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Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Underwater Nonlinear Acoustic Speaker.  

E-Print Network (OSTI)

??In this work an acoustic parametric array for underwater use was designed, built and tested. An acoustic parametric array creates a focused beam of sound… (more)

Andersson, Sara

2011-01-01T23:59:59.000Z

2

Iterative equalization and decoding applied to underwater acoustic communication  

E-Print Network (OSTI)

1.1 Shallow Underwater Acoustic Channels . . . . . . . .and Decoding Approach for Underwater Acoustic Commu-Equalization and Decoding of Underwater Acoustic Using Array

Sifferlen, James F.

2008-01-01T23:59:59.000Z

3

Cooperative Schemes for Underwater Acoustic Communications (AQU 3)  

E-Print Network (OSTI)

Cooperative Schemes for Underwater Acoustic CommunicationsIntroduction: Underwater Cooperative CommunicationsMotivation Traditional underwater communications Used for

Madhavan Vajapeyam; Satish Vedantam; Urbashi Mitra

2006-01-01T23:59:59.000Z

4

Sparse Multichannel Estimation Algorithm for Cooperative Underwater Acoustic Communication Networks  

E-Print Network (OSTI)

Introduction: Cooperative Underwater Acoustic Communicationsgain for wireless and underwater network in interference-

Richard, Nick; Mitra, Urbasi

2007-01-01T23:59:59.000Z

5

Proceedings of the 11th European Conference on Underwater Acoustics ACHIEVABLE RATES OF UNDERWATER ACOUSTIC OFDM  

E-Print Network (OSTI)

Proceedings of the 11th European Conference on Underwater Acoustics ACHIEVABLE RATES OF UNDERWATER-Telecom, Telecom Bretagne, UMR CNRS 6285 Lab-STICC, Ueb, Brest, France J.-M. Passerieux Thales Underwater Systems maintaining acceptable data rates, remains one of the major difficulty faced by underwater acoustic

Paris-Sud XI, Université de

6

MAC and Routing Protocols for Mobile Underwater Acoustic Sensor Swarms  

E-Print Network (OSTI)

Pressure Routing for Underwater Sensor Networks . . . . . .of Aloha Protocols for Underwater Acoustic Sensor Networks.Critical Applications in Underwater Sensor Networks. In

Noh, Young Tae

2012-01-01T23:59:59.000Z

7

Time synchronization for underwater acoustic sensor networks.  

E-Print Network (OSTI)

??The unique properties of underwater acoustic communications, such as large and time-varying propagation, low and range dependent bandwidth, and adverse operating environment make the synchronization… (more)

Khandoker, Tarik-Ul Islam

2012-01-01T23:59:59.000Z

8

SPARSE UNDERWATER ACOUSTIC IMAGING: A CASE STUDY Nikolaos Stefanakis  

E-Print Network (OSTI)

SPARSE UNDERWATER ACOUSTIC IMAGING: A CASE STUDY Nikolaos Stefanakis , Jacques Marchal , Valentin de Beaulieu 35042 Rennes Cedex, France ABSTRACT Underwater acoustic imaging is traditionally 3D underwater imaging using a newly built flexible-configuration sonar device. The computational

Paris-Sud XI, Université de

9

Piezoelectric materials used in underwater acoustic transducers  

Science Conference Proceedings (OSTI)

Piezoelectric materials have been used in underwater acoustic transducers for nearly a century. In this paper, we reviewed four different types of piezoelectric materials: piezoelectric ceramics, single crystals, composites, and polymers, which are widely used in underwater acoustic transducers nowadays. Piezoelectric ceramics are the most dominant material type and are used as a single-phase material or one of the end members in composites. Piezoelectric single crystals offer outstanding electromechanical response but are limited by their manufacturing cost. Piezoelectric polymers provide excellent acoustic impedance matching and transducer fabrication flexibility although their piezoelectric properties are not as good as ceramics and single crystals. Composites combined the merits of ceramics and polymers and are receiving increased attention. The typical structure and electromechanical properties of each type of materials are introduced and discussed with respect to underwater acoustic transducer applications. Their advantages and disadvantages are summarized. Some of the critical design considerations when developing underwater acoustic transducers with these materials are also touched upon.

Li, Huidong; Deng, Zhiqun; Carlson, Thomas J.

2012-07-07T23:59:59.000Z

10

Underwater Acoustic Sensor Networks: Research Challenges  

E-Print Network (OSTI)

Underwater sensor nodes will find applications in oceanographic data collection, pollution monitoring, o#shore exploration, disaster prevention, assisted navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs, AUVs), equipped with sensors, will enable the exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking is the enabling technology for these applications. Underwater networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area.

Ian Akyildiz Dario; Ian F. Akyildiz; Dario Pompili; Tommaso Melodia

2005-01-01T23:59:59.000Z

11

Underwater Acoustic Sensor Networks: Research Challenges  

E-Print Network (OSTI)

Underwater sensor nodes will find applications in oceanographic data collection, pollution monitoring, o#shore exploration, disaster prevention, assisted navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs, AUVs), equipped with sensors, will enable the exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking is the enabling technology for these applications. Underwater networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. In this

Ian F. Akyildiz; Dario Pompili; Tommaso Melodia

2005-01-01T23:59:59.000Z

12

Spectrally efficient underwater acoustic communications : channel characterization and design aspects for OFDM  

E-Print Network (OSTI)

with L = 9 for an underwater channel impulse response with Ladaptive modulation in underwater acoustic communications,”Adaptive OFDM for underwater acoustic channels with limited

Radoševi?, Andreja

2012-01-01T23:59:59.000Z

13

Spatiotemporal processing and time-reversal for underwater acoustic communications  

E-Print Network (OSTI)

High-rate underwater acoustic communication can be achieved using transmitter/receiver arrays. Underwater acoustic channels can be characterized as rapidly time-varying systems that suffer severe Inter Symbol Interferences ...

Wang, Daniel Y

2005-01-01T23:59:59.000Z

14

Reliable Data Communication and Storage in Underwater Acoustic Networks.  

E-Print Network (OSTI)

??Underwater acoustic communications (UAC) and networking (UAN) are promising paradigms for various oceanic applications. However, acoustic signal transmissions are characterized by long propagation delay, frequency-dependent… (more)

Cao, Rui

2011-01-01T23:59:59.000Z

15

Underwater acoustic imaging: physically-motivated sparse models  

E-Print Network (OSTI)

Underwater acoustic imaging: physically-motivated sparse models and validation on real data N hal-00677287,version1-4Jun2012 #12;Underwater acoustic imaging (UWA)hal-00677287,version1-4Jun2012 #12;Underwater acoustic imaging: direct problem Successive emission sequences, or pings, indexed by p. ep

Paris-Sud XI, Université de

16

Proceedings of the 11 European Conference on Underwater Acoustics  

E-Print Network (OSTI)

Proceedings of the 11 th European Conference on Underwater Acoustics INCOHERENT CHANGE DETECTION on Underwater Acoustics images. This allows performing a segmentation of the master image at the coarser stage,version1-7Sep2012 #12;Proceedings of the 11 th European Conference on Underwater Acoustics The idea

Paris-Sud XI, Université de

17

Underwater Localization in Sparse 3D Acoustic Sensor Networks  

E-Print Network (OSTI)

Underwater Localization in Sparse 3D Acoustic Sensor Networks Wei Cheng1,2, Amin Y. Teymorian the localization problem in sparse 3D underwater sensor networks. Considering the fact that depth information is typically available for underwater sensors, we transform the 3D underwater positioning problem into its two

Cheng, Xiuzhen "Susan"

18

Silent Positioning in Underwater Acoustic Sensor Networks  

E-Print Network (OSTI)

In this paper, we present a silent positioning scheme termed as UPS for underwater acoustic sensor networks. UPS relies on the time-difference of arrivals measured locally at a sensor to detect range differences from the sensor to four anchor nodes. These range differences are averaged over multiple beacon intervals before they are combined to estimate the 3D sensor location through trilateration. UPS requires no time-synchronization and provides location privacy at underwater vehicles/sensors whose locations need to be determined. To study the performance of UPS, we model the underwater acoustic channel as a modified Ultra Wide Band (UWB) S-V model: the arrival of each path cluster and paths within each cluster follow double Poisson distributions, and the multipath channel gain follows a Rician distribution. Based on this channel model, we perform both theoretical analysis and simulation study on the position error of UPS under acoustic fading channels. The obtained results indicate that UPS is an effective scheme for underwater vehicle/sensor self-positioning.

Xiuzhen Cheng; Haining Shu; Qilian Liang; David Hung-chang Du

2007-01-01T23:59:59.000Z

19

Design of a low-cost underwater acoustic modem for short- range sensor networks  

E-Print Network (OSTI)

of Optical Waves Underwater . . . . . . . 3.2.2 ExistingChapter 4 Existing Underwater Acoustic Modems 4.1 CommercialControl Structure of Symbol Synchronization for Underwater

Benson, Bridget

2010-01-01T23:59:59.000Z

20

Underwater Acoustic Sensor Network with Energy Harvesting Nodes.  

E-Print Network (OSTI)

??This thesis explores the possibility of a self sustained and service free Underwater Acoustic Sensor Network (UASN). The network nodes are installed along a subsea… (more)

Huseby, Morten

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Use of an acoustic network as an underwater positioning system .  

E-Print Network (OSTI)

??Underwater acoustic networks provide an interface between UUVs and surface or land-based control systems. By exploiting range data measured incidental to communications on these networks… (more)

Reed, Michael S.

2006-01-01T23:59:59.000Z

22

Cooperative Communication over Underwater Acoustic Channels.  

E-Print Network (OSTI)

??As diverse and data-heavy underwater applications emerge, demanding requirements are further imposed on underwater wireless communication systems. Future underwater wireless communication networks might consist of… (more)

Aldharrab, Suhail Ibrahim

2013-01-01T23:59:59.000Z

23

Focused beam routing protocol for underwater acoustic networks  

Science Conference Proceedings (OSTI)

Multi-hop transmission is considered for large coverage areas in bandwidth-limited underwater acoustic networks. In this paper, we present a scalable routing technique based on location information, and optimized for minimum energy per bit consumption. ... Keywords: power control, routing, underwater acoustic networks

Josep Miquel Jornet; Milica Stojanovic; Michele Zorzi

2008-09-01T23:59:59.000Z

24

Challenges for Efficient Communication in Underwater Acoustic Sensor Networks  

E-Print Network (OSTI)

Abstract — Ocean bottom sensor nodes can be used for oceanographic data collection, pollution monitoring, offshore exploration and tactical surveillance applications. Moreover, Unmanned or Autonomous Underwater Vehicles (UUVs, AUVs), equipped with sensors, will find application in exploration of natural undersea resources and gathering of scientific data in collaborative monitoring missions. Underwater acoustic networking is the enabling technology for these applications. Underwater Networks consist of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over a given area. In this paper, several fundamental key aspects of underwater acoustic communications are investigated. Different architectures for two-dimensional and three-dimensional underwater sensor networks are discussed, and the underwater channel is characterized. The main challenges for the development of efficient networking solutions posed by the underwater environment are detailed at all layers of the protocol stack. Furthermore, open research issues are discussed and possible solution approaches are outlined. I.

Ian F. Akyildiz; Dario Pompili; Tommaso Melodia

2004-01-01T23:59:59.000Z

25

An underwater acoustic channel model using ray tracing in ns-2  

Science Conference Proceedings (OSTI)

Underwater Acoustic Sensor Network (UASN) is the enabling technology for real-time underwater monitoring and data collection. The costly underwater trials and unknown underwater acoustic modem infrastructures increase the need and importance of a reliable ... Keywords: ns-2, ray tracing, sensor network, underwater

Tarik Çinar; M. Bülent Örencik

2009-12-01T23:59:59.000Z

26

Direct-form adaptive equalization for underwater acoustic communication  

E-Print Network (OSTI)

Adaptive equalization is an important aspect of communication systems in various environments. It is particularly important in underwater acoustic communication systems, as the channel has a long delay spread and is subject ...

Yellepeddi, Atulya

2012-01-01T23:59:59.000Z

27

Examining transmission power in minimum capacity underwater acoustic networks  

E-Print Network (OSTI)

This paper explores the prospect of reducing the transmission power required to operate links within an underwater acoustic network by minimizing the total capacity of the network while maintaining certain data flow ...

Stanchak, Kathryn E

2010-01-01T23:59:59.000Z

28

Reduced bandwidth frequency domain equalization for underwater acoustic communications  

E-Print Network (OSTI)

Two challenges facing adaptive decision feedback equalizers (DFEs) in the underwater acoustic channel are those of the channel changing too rapidly to allow for the stable adaptation of the number of coefficients required ...

Wornell, Gregory W.

29

Listening to Raindrops from Underwater: An Acoustic Disdrometer  

Science Conference Proceedings (OSTI)

Different sized raindrops splashing on a water surface produce sound underwater that is distinctive and can be used to measure the drop size distribution in the rain. Five acoustically significant raindrop sizes are described. An inversion of the ...

Jeffrey A. Nystuen

2001-10-01T23:59:59.000Z

30

MAC and Routing Protocols for Mobile Underwater Acoustic Sensor Swarms.  

E-Print Network (OSTI)

??Underwater Acoustic Sensor Networks (UW-ASNs) have recently been proposed as a way to explore and observe the ocean, which covers two-thirds of the Earth's surface.… (more)

Noh, Young Tae

2012-01-01T23:59:59.000Z

31

Design, implementation and performance evaluation of security services for Underwater Acoustic Networks.  

E-Print Network (OSTI)

??Underwater Acoustic Networks (UANs), composed by Autonomous Underwater Vehicles (AUVs) are part of a new network paradigm that is being proposed for different uses like… (more)

MASSANTI, GIULIANO

2011-01-01T23:59:59.000Z

32

Underwater acoustic sensor networks: research challenges Ian F. Akyildiz *, Dario Pompili, Tommaso Melodia  

E-Print Network (OSTI)

Underwater acoustic sensor networks: research challenges Ian F. Akyildiz *, Dario Pompili, Tommaso September 2004; accepted 21 January 2005 Abstract Underwater sensor nodes will find applications navigation and tactical surveillance applications. Moreover, unmanned or autonomous underwater vehicles (UUVs

Baykal, Buyurman

33

A Comparative Analysis and Experimental Study on Wireless Aerial and Underwater Acoustic  

E-Print Network (OSTI)

A Comparative Analysis and Experimental Study on Wireless Aerial and Underwater Acoustic underwater acoustic sensor networks through the use of audio hardware built in to the sensor modules. In this paper, we explore the potential of the acoustic communication system for both aerial and underwater

Lopes, Cristina Videira

34

A broadband underwater acoustic modem implementation using coherent OFDM  

E-Print Network (OSTI)

Abstract — Multicarrier modulation in the form of orthogonal frequency division multiplexing (OFDM) has prevailed in recent broadband wireless systems over radio channels. In this senior design project, we have implemented an acoustic OFDM modem that transmits digital data through sound propagation. We have demonstrated OFDM transmission first in air, and then in water. We find that the underwater channel is much more complex than the air channel, and careful signal designs are needed for underwater transmissions. We have also handled another difficulty incurred by sampling rate mismatches at the transmitter and the receiver due to low-cost sampling devices. With two-way communication capabilities, this project provides a simple online chatting tool between two computers relying on acoustic links. Index Terms — OFDM, multicarrier transmission, underwater acoustic communication.

Sean Mason; Robert Anstett; Nicoletti Anicette; Shengli Zhou

2007-01-01T23:59:59.000Z

35

A New Discrete Transparent Boundary Condition for Standard and Wide Angle "Parabolic" Equations in Underwater Acoustics  

E-Print Network (OSTI)

in Underwater Acoustics ANTON ARNOLD1,2 AND MATTHIAS EHRHARDT1 1 Fachbereich Mathematik TU Berlin, MA 6­2 Stra�e in underwater acoustics, where they have been introduced by Tappert [31]. An account on the vast recent literature is given in the survey article [21]. In oceanography one wants to calculate the underwater

Ehrhardt, Matthias

36

Tier-Based Underwater Acoustic Routing for Applications with Reliability and Delay Constraints  

E-Print Network (OSTI)

Tier-Based Underwater Acoustic Routing for Applications with Reliability and Delay Constraints Li for underwater sensor networks is still an open research problem because of the unique charac- teristics of the underwater acoustic communication channel such as limited bandwidth, high and variable propagation delays

Melodia, Tommaso

37

An Aquatic Acoustic Metrics Interface Utility for Underwater Sound Monitoring and Analysis  

SciTech Connect

Fishes and other marine mammals suffer a range of potential effects from intense sound sources generated by anthropogenic underwater processes such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording devices (USR) were built to monitor the acoustic sound pressure waves generated by those anthropogenic underwater activities, so the relevant processing software becomes indispensable for analyzing the audio files recorded by these USRs. However, existing software packages did not meet performance and flexibility requirements. In this paper, we provide a detailed description of a new software package, named Aquatic Acoustic Metrics Interface (AAMI), which is a Graphical User Interface (GUI) designed for underwater sound monitoring and analysis. In addition to the general functions, such as loading and editing audio files recorded by USRs, the software can compute a series of acoustic metrics in physical units, monitor the sound's influence on fish hearing according to audiograms from different species of fishes and marine mammals, and batch process the sound files. The detailed applications of the software AAMI will be discussed along with several test case scenarios to illustrate its functionality.

Ren, Huiying; Halvorsen, Michele B.; Deng, Zhiqun; Carlson, Thomas J.

2012-05-31T23:59:59.000Z

38

Three-Dimenisional Routing in Underwater Acoustic Sensor Networks  

E-Print Network (OSTI)

Underwater sensor networks will find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation, and tactical surveillance applications. In this paper, the problem of data gathering in a 3D underwater acoustic sensor network is investigated at the network layer, by considering the interactions between the routing functions and the characteristics of the underwater channel. Two routing algorithms are proposed for delay-insensitive and delay-sensitive sensor network applications, respectively. The proposed distributed algorithm for delay-insensitive applications allows each node to select its next hop, with the objective of minimizing the energy consumption taking into account the varying condition of the underwater channel. A centralized algorithm for delay-sensitive routing in an underwater environment is proposed. The solution relies on topology information gathered by a surface station, which optimally configures the network paths. The proposed algorithms are shown to achieve the performance targets of the underwater environment by means of simulation. Categories and Subject Descriptors:

Dario Pompili; Tommaso Melodia

2005-01-01T23:59:59.000Z

39

Underwater acoustic MIMO OFDM: an experimental analysis  

E-Print Network (OSTI)

Performance of multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) is analyzed on an experimental shallow water acoustic channel. Different modulation levels, numbers of subcarriers and ...

Palou Visa, Guillem

40

Characterisation of long-range horizontal performance of underwater acoustic communication.  

E-Print Network (OSTI)

??Underwater acoustic communication is a rapidly progressing field of technology, largely due to recent advances in low cost and power efficient digital signal processors. Unfortunately,… (more)

Pusey, Grant Mark

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Athanassis Anastasiou MRes Project: A Robust Acoustic Link for Underwater Data  

E-Print Network (OSTI)

Athanassis Anastasiou MRes Project: A Robust Acoustic Link for Underwater Data Communications The work carried out in this project contains extensive modelling of various underwater communications an appropriate Forward Error Control coding method according to the quality of the underwater channel it operates

Abu-Rgheff, Mosa Ali

42

Use of high performance computing resources for underwater acoustic modeling.  

Science Conference Proceedings (OSTI)

The majority of standard underwater propagation models provide a two?dimensional (range and depth) acoustic field for a single frequency point source. Computational resource demand increases considerably when the three?dimensional acoustic field of a broad?band spatially extended source is of interest. An upgrade of the standard parabolic equationmodel RAM for use in a high?performance computing (HPC) environment is discussed. A benchmarked upgraded version of RAM is used in the Louisiana Optical Network Initiative HPC?environment to model the three?dimensional acoustic field of a seismic airgun array. Four?dimensional visualization (time and space) of the generated data volume is also addressed. [Research supported by the Louisiana Optical Network Initiative

Anca M. Niculescu; Natalia A. Sidorovskaia; Peter Achi; Arslan M. Tashmukhambetov; George E. Ioup; Juliette W. Ioup

2009-01-01T23:59:59.000Z

43

Underwater acoustic navigation with the WHOI micro-modem  

E-Print Network (OSTI)

Abstract — The WHOI Micro-Modem is a compact, low-power acoustic transceiver that can provide both acoustic telemetry and navigation. Its size and versatility make it ideal for integration in autonomous underwater vehicles (AUVs). The modem supports the use of both broadband and narrowband transponders for long baseline navigation systems, has a modem-to-modem ranging capability, and can be configured to provide synchronous oneway ranging, when integrated with a precision clock. This paper gives an overview of the different navigation systems supported by the Micromodem and presents the results from field tests conducted on the SeaBED AUV in deployments in Greece, the Bluefin AUV, and whale localizations in the Stellwagen Bank Marine Sanctuary. I.

Ipa Singh; Matthew Grund; Brian Bingham; Ryan Eustice; Hanumant Singh; Lee Freitag

2006-01-01T23:59:59.000Z

44

K-distribution fading models for Bayesian estimation of an underwater acoustic channel  

E-Print Network (OSTI)

Current underwater acoustic channel estimation techniques generally apply linear MMSE estimation. This approach is optimal in a mean square error sense under the assumption that the impulse response fluctuations are well ...

Laferriere, Alison Beth

2011-01-01T23:59:59.000Z

45

Acoustic Doppler Velocimeter Flow Measurement from an Autonomous Underwater Vehicle with Applications to Deep Ocean Convection  

Science Conference Proceedings (OSTI)

The authors present a new modality for direct measurement of ocean flow, achieved by combining the resolution and precision of an acoustic Doppler velocimeter with the mobility of an autonomous underwater vehicle. To obtain useful measurements, ...

Yanwu Zhang; Knut Streitlien; James G. Bellingham; Arthur B. Baggeroer

2001-12-01T23:59:59.000Z

46

Underwater acoustic signal separation based on prior estimation of the channel impulse response  

Science Conference Proceedings (OSTI)

An underwater acoustic signals separation method based on prior information about the channel impulse response (IR) is presented. Using a sound speed profile measured in a real world environment, the IR of the ocean is estimated with normal mode theory ...

S. Bonnifay; K. Yao; C. Jutten

2000-06-01T23:59:59.000Z

47

Design and analysis of a high-rate acoustic link for underwater video transmission  

E-Print Network (OSTI)

A high bit rate acoustic link for underwater video transmission is examined. Currently, encoding standards support video transmission at bit rates as low as 64 kbps. While this rate is still above the limit of commercially ...

Pelekanakis, Konstantinos

2004-01-01T23:59:59.000Z

48

On Joint Frequency and Power Allocation in a Cross-Layer Protocol for Underwater Acoustic Networks  

E-Print Network (OSTI)

Path loss in an underwater acoustic channel depends not only on the transmission distance, but also on the signal frequency. As a result, the useful bandwidth decreases with distance, a feature not normally present in ...

Jornet, Josep Miquel

49

Elastic parabolic equation solutions for underwater acoustic problems using seismic sources  

E-Print Network (OSTI)

Elastic parabolic equation solutions for underwater acoustic problems using seismic sources Scott D theoretic methods, and attempts to model them with fluid-bottom parabolic equation solu- tions suggest between elastic and acoustic waves, current elastic parabolic equation solutions must be modified to allow

50

Underwater Acoustic Networks: Channel Models and Network Coding based Lower Bound to Transmission Power for Multicast  

E-Print Network (OSTI)

The goal of this paper is two-fold. First, to establish a tractable model for the underwater acoustic channel useful for network optimization in terms of convexity. Second, to propose a network coding based lower bound for transmission power in underwater acoustic networks, and compare this bound to the performance of several network layer schemes. The underwater acoustic channel is characterized by a path loss that depends strongly on transmission distance and signal frequency. The exact relationship among power, transmission band, distance and capacity for the Gaussian noise scenario is a complicated one. We provide a closed-form approximate model for 1) transmission power and 2) optimal frequency band to use, as functions of distance and capacity. The model is obtained through numerical evaluation of analytical results that take into account physical models of acoustic propagation loss and ambient noise. Network coding is applied to determine a lower bound to transmission power for a multicast scenario, fo...

Lucani, Daniel E; Stojanovic, Milica

2008-01-01T23:59:59.000Z

51

Underwater Acoustic Localisation in the context of Autonomous Submersibles .  

E-Print Network (OSTI)

??With the advancement of the field of underwater robotics, the amount of autonomy embodied in the vehicles themselves have considerably increased while making it possible… (more)

Kottege, Navinda

2011-01-01T23:59:59.000Z

52

Oceanic Rainfall Detection and Classification in Tropical and Subtropical Mesoscale Convective Systems Using Underwater Acoustic Methods  

Science Conference Proceedings (OSTI)

Measurements of the underwater sound produced by rain were made at three U.S. coastal sites in a study to determine the feasibility and limitations of the acoustic detection and classification of rainfall over water. In the analysis of the rain ...

Peter G. Black; John R. Proni; John C. Wilkerson; Christopher E. Samsury

1997-09-01T23:59:59.000Z

53

Wormhole-Resilient Secure Neighbor Discovery in Underwater Acoustic Networks  

E-Print Network (OSTI)

is vulnerable to the wormhole attack by which the adversary uses secret wormhole links to make distant nodes, undersea explorations, disaster preven- tion, tactical surveillance, underwater warfare, and so on [3, essentially an out-of-band and low-latency channel, between two distant network locations. They then tunnel

Zhang, Rui

54

Underwater Acoustic Detection of Ultra High Energy Neutrinos  

E-Print Network (OSTI)

We investigate the acoustic detection method of 10^18-20 eV neutrinos in a Mediterranean Sea environment. The acoustic signal is re-evaluated according to dedicated cascade simulations and a complex phase dependant absorption model, and compared to previous studies. We detail the evolution of the acoustic signal as function of the primary shower characteristics and of the acoustic propagation range. The effective volume of detection for a single hydrophone is given taking into account the limitations due to sea bed and surface boundaries as well as refraction effects. For this 'benchmark detector' we present sensitivity limits to astrophysical neutrino fluxes, from which sensitivity bounds for a larger acoustic detector can be derived. Results suggest that with a limited instrumentation the acoustic method would be more efficient at extreme energies, above 10^20 eV.

V. Niess; V. Bertin

2005-11-21T23:59:59.000Z

55

Software acoustic modems for short range mote-based underwater sensor networks  

E-Print Network (OSTI)

Abstract — Most recent work in underwater network development has relied on using expensive commercial acoustic modems or on building custom transceivers for each application to establish acoustic communication links among the sensors. Using commercial modems or designing custom hardware may require prohibitive monetary or time investment for many applications. Our work proposes the design of software acoustic modems that can utilize built-in microphones and speakers on the relatively cheap Tmote Invent platforms. The software modem and built-in hardware can be used for establishing acoustic communication in a short range shallow water network for environmental monitoring. In this paper, we introduce the application and architecture for our proposed network, as well as the initial design of our acoustic communication system. Our experiments with generic acoustic hardware to profile this underwater communication channel reveal that this channel favors frequencies below 3Khz, a result which guides the design choices for our FSK software modem. We perform experiments with our software modem/generic hardware system to explore the system’s data transfer capability. The data communications experiments confirm the system’s capability of transferring information in the order of tens of bits per second for a communications range of up to 10 meters. I.

Raja Jurdak; Cristina Videira Lopes; Pierre Baldi

2006-01-01T23:59:59.000Z

56

Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter  

Science Conference Proceedings (OSTI)

The Juvenile Salmon Acoustic Telemetry System (JSATS) project supported by the U.S. Army Corps of Engineers, Portland District, has yielded the smallest acoustic fish tag transmitter commercially available to date. In order to study even smaller fish populations and make the transmitter injectable by needles, the JSATS acoustic micro transmitter needs to be further downsized. As part of the transmitter downsizing effort some of the design parameters of the lead zirconate titanate (PZT) ceramic tube transducer in the transmitter were studied, including the type of PZT, the backing material, the necessary drive voltage, the transmitting bandwidth and the length of the transducer. It was found that, to satisfy the 156-dB source level requirement of JSATS, a square wave with a 10-volt amplitude is required to drive 'soft' PZT transducers. PZT-5H demonstrated the best source level performance. For Navy types I and II, 16 volts or 18 volts were needed. Ethylene-propylene-diene monomer (EPDM) closed-cell foam was found to be the backing material providing the highest source level. The effect of tube length on the source level is also demonstrated in this paper, providing quantitative information for downsizing of small piezoelectric transmitters.

Li, Huidong; Deng, Zhiqun; Yuan, Yong; Carlson, Thomas J.

2012-07-02T23:59:59.000Z

57

QUO VADIS: QoS-aware Underwater Optimization Framework for Inter-vehicle Communication using Acoustic Directional Transducers  

E-Print Network (OSTI)

Abstract—Underwater acoustic communications consume a significant amount of energy due to the high transmission power (10?50 W) and long data packet transmission times (0.1?1 s). Mobile Autonomous Underwater Vehicles (AUVs) can conserve energy by waiting for the ‘best ’ network topology configuration, e.g., a favorable alignment, before starting to communicate. Due to the frequency-selective underwater acoustic ambient noise and high medium power absorption – which increases exponentially with distance – a shorter distance between AUVs translates into a lower transmission loss and a higher available bandwidth. By leveraging the predictability of AUV trajectories, a novel solution is proposed that optimizes communications by delaying packet transmissions in order to wait for a favorable network topology (thus trading end-to-end delay for energy and/or throughput). In addition, the solution proposed – which is implemented and compared with other solutions using an emulator that integrates underwater acoustic WHOI Micro-Modems – exploits the frequency-dependent radiation pattern of underwater acoustic transducers to reduce communication energy consumption by adjusting the transducer directivity on-the-fly. I.

Baozhi Chen; Dario Pompili

2011-01-01T23:59:59.000Z

58

Ray-based analysis of the interference striation pattern in an underwater acoustic waveguide  

E-Print Network (OSTI)

In some underwater acoustic waveguides with specially selected sound speed profiles striations or fringes of the interference pattern are determined by a single parameter \\beta\\ called the waveguide (or Chuprov) invariant. In the present paper it is shown that an analytical description of fringes may be possible in a waveguide with an arbitrary sound speed profile. A simple analytical expression is obtained for smooth lines formed by local maxima of the interference pattern. This result is valid at long enough ranges. It is derived proceeding from a known relation connecting the differences of ray travel times and the action variables of ray paths.

Virovlyansky, A L

2013-01-01T23:59:59.000Z

59

Acoustic Timing Simulation of Active Beacons for  

E-Print Network (OSTI)

A simulation of freely-deployed active underwater beacons to estimate the tow path of a Synthetic Aperture Sonar (SAS) towfish is presented. Knowledge of the tow path allows the removal of motion induced blurring in the SAS images. The beacons sit on the seabed listening for acoustic chirps from the sonar and retransmit back in a different frequency band after a fixed time delay. After reconstruction the beacons appear in the SAS image as point-source targets, blurred by towfish motion, from which the tow-path can be determined by triangulation. The effect of reconstructing the continuous towfish motion as discrete along-track `hops' is also investigated. Simulations of a towfish path with 20 cm sway amplitude and typical measurement timing errors show a significant improvement in image quality using two active beacons.

Measuring The Tow-Path; Edward N. Pilbrow; Michael P. Hayes

2003-01-01T23:59:59.000Z

60

A CDMA-based Medium . . . UnderWater Acoustic Sensor Networks  

E-Print Network (OSTI)

UnderWater Acoustic Sensor Networks (UW-ASNs) ... performing collaborative monitoring tasks. In this article, UW-MAC, a distributed Medium Access Control (MAC) protocol designed for UW-ASNs, is introduced. The proposed MAC protocol is a transmitter-based Code Division Multiple Access (CDMA) scheme that incorporates a novel closed-loop distributed algorithm to jointly set the optimal transmit power and code length. CDMA is the most promising physical layer and multiple access technique for UW-ASNs because it is robust to frequencyselective fading, it compensates for the effect of multipath at the receiver, and it allows receivers to distinguish among signals simultaneously transmitted by multiple devices. UW-MAC aims at achieving three objectives, i.e., guarantee i) high network throughput, ii) low channel access delay, and iii) low energy consumption. It is demonstrated that UW-MAC simultaneously achieves these three objectives in deep water communications (where the ocean depth is more than 100 m), which are usually not severely affected by multipath. In shallow water communications, which may be heavily affected by multipath, it dynamically finds the optimal trade-off among these objectives according to the application requirements. UW-MAC is the first protocol that leverages CDMA properties to achieve multiple access to the scarce underwater bandwidth, while other protocols tailored for this environment have considered CDMA merely from a physical layer perspective. Experiments show that UW-MAC outperforms many existing MAC protocols tuned for the underwater environment under different architecture scenarios and simulation settings.

Dario Pompili; Tommaso Melodia; Ian F. Akyildiz

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Cooperative Localization for Autonomous Underwater Vehicles  

E-Print Network (OSTI)

This paper describes an algorithm for distributed acoustic navigation for Autonomous Underwater Vehicles

Bahr, Alexander

62

Strategies in tracking and localization of distributed underwater systems  

E-Print Network (OSTI)

decoding approach for underwater acoustic communications",Mobility Prediction for Underwater Sensor Networks", W U W NH . V . , "Localization in Underwater Sensor Networks Survey

Mirza, Diba

2010-01-01T23:59:59.000Z

63

State of the art in protocol research for underwater acoustic sensor networks  

E-Print Network (OSTI)

Underwater networks of sensors have the potential to enable unexplored applications and to enhance our ability to observe and predict the ocean. In this paper, architectures for twodimensional and three-dimensional underwater sensor networks are proposed. A detailed overview on the current solutions for medium access control, network, and transport layer protocols is given and open research issues are discussed. I.

Ian F. Akyildiz; Dario Pompili; Tommaso Melodia

2007-01-01T23:59:59.000Z

64

Acoustical Rainfall Analysis: Rainfall Drop Size Distribution Using the Underwater Sound Field  

Science Conference Proceedings (OSTI)

Rainfall estimation is difficult, especially in oceanic regions where land-based techniques are unavailable. Fortunately, rain produces a loud and unique sound underwater that can be used to detect and quantify rainfall. Laboratory studies of the ...

Jeffrey A. Nystuen

1996-02-01T23:59:59.000Z

65

A Comparative Analysis and Experimental Study on Wireless Aerial and Underwater Acoustic Communications  

Science Conference Proceedings (OSTI)

Widely available speakers and microphones in electronic devices motivate the use of generic audio hardware to establish acoustic communication links. Acoustic communication with generic hardware requires software modems for data modulation and demodulation. ...

Raja Jurdak; Cristina Videira Lopes; Pedro M. Q. Aguiar; Pierre Baldi

2006-08-01T23:59:59.000Z

66

State-of-the-art in protocol research for underwater acoustic sensor networks  

E-Print Network (OSTI)

In this paper, architectures for two-dimensional and three-dimensional underwater sensor networks are discussed. A detailed overview on the current solutions for medium access control, network, and transport layer protocols are given and open research issues are discussed. Categories and Subject Descriptors:

Ian F. Akyildiz; Dario Pompili; Tommaso Melodia

2006-01-01T23:59:59.000Z

67

Dusky Dolphin (Lagenorhynchus obscurus) Underwater Bait-Balling Behaviors and Acoustic Signals: A Comparison Between Argentina and New Zealand  

E-Print Network (OSTI)

I characterized dusky dolphin (Lagenorhynchus obscurus) underwater bait-balling behaviors and acoustic signals, and compared data between Argentina and New Zealand (NZ) to investigate the roles of ecology versus social learning. I quantified prey herding and capturing behaviors from video footage, and I analyzed acoustic signals from narrowband recordings. In both locations, I related bait-balling behaviors and acoustic signals to group and prey ball sizes. In NZ, I also related dolphin behaviors to prey ball escape behaviors and acoustic signal parameters to examine proximate functions. Observed herding behaviors typically involved dolphins swimming around or under a prey ball using a side body orientation, while dolphins typically captured fish from the side of a prey ball using a ventral orientation. Coordinated prey-capture behaviors may have made it easier for dolphins to capture fish by trapping fish between dolphins. Signals were categorized as click trains, burst pulses, and combinations due to a bimodal inter-click interval distribution. I observed 3 whistle-like chirp-screams, but no whistles. Sequences of burst pulses also occurred that contained 2-14 burst pulses that aurally and visually appeared closely matched. Similarities between locations suggest that ecological context related to broad behavioral and acoustic parameters, while social learning differences may occur on a finer scale. In NZ, prey balls exhibited horizontal and vertical movements, but the only behavior that preceded escape was “funneling”, the brief formation of a ball shape where the height was at least twice the width. Dolphin behaviors that related to prey balls ascending were type of herding pass, location of prey-capture attempts, and body orientation during attempts. These behavioral parameters may also be used to counter vertical prey escape behaviors. In NZ, all signal categories had a direct or indirect role in capturing prey. Click train-burst pulses were likely used for echolocating on prey, burst pulses and sequences appeared to have communication roles, and the role of click trains was ambiguous. No signal categories appeared to have a herding function, but the sheer number of signals emitted may have caused fish to cluster together more tightly and therefore facilitated capture.

Vaughn, Robin

2011-08-01T23:59:59.000Z

68

DISCRETE TRANSPARENT BOUNDARY CONDITIONS FOR WIDE ANGLE PARABOLIC EQUATIONS IN UNDERWATER  

E-Print Network (OSTI)

DISCRETE TRANSPARENT BOUNDARY CONDITIONS FOR WIDE ANGLE PARABOLIC EQUATIONS IN UNDERWATER ACOUSTICS "parabolic" equations (WAPEs) in underwater acoustics (assuming cylindrical symmetry). Existing the discretization of transparent bottom boundary conditions. In oceanography one wants to calculate the underwater

Ehrhardt, Matthias

69

Using optical communication for remote underwater robot operation  

E-Print Network (OSTI)

Underwater vehicles are typically operated using a tether or a slow acoustic link. We present an underwater optical communication system that enables a high-throughput and low-latency link to an underwater robot. The optical ...

Doniec, Marek Wojciech

70

Blue whale response to underwater noise from commercial ships  

E-Print Network (OSTI)

D. , 1976. Mechanics of Underwater Noise. Pergamon PressD. , 1993. On ocean underwater ambient noise. AcousticsRichmond, M.E. , 2005. Underwater, low- frequency noise in a

McKenna, Megan Frances

2011-01-01T23:59:59.000Z

71

Underwater Sensor Network (UWSN) LabUnderwater Sensor Network (UWSN) Lab AquaAqua--fModemfModem: A Stand: A Stand--alone Underwateralone Underwater  

E-Print Network (OSTI)

Underwater Sensor Network (UWSN) LabUnderwater Sensor Network (UWSN) Lab AquaAqua--fModemfModem: A Stand: A Stand--alone Underwateralone Underwater Acoustic Modem Based on OFDM TechnologyAcoustic ModemUniversity of Connecticut OFDM is one appealing solution for highOFDM is one appealing solution for high--rate underwater

Zhou, Shengli

72

Underwater wireless ad hoc sensor networks are aimed at remotely monitoring various aquatic activities, such as marine biological and zoological lives, geological changes, and  

E-Print Network (OSTI)

Abstract Underwater wireless ad hoc sensor networks are aimed at remotely monitoring various aquatic activities, such as marine biological and zoological lives, geological changes, and underwater quality of service is more difficult in underwater net- works due to large underwater propagation delay

Kumar, M. Jagadesh

73

Designing a wireless underwater optical communication system  

E-Print Network (OSTI)

Though acoustic modems have long been the default wireless communication method for underwater applications due to their long range, the need for high speed communication has prompted the exploration of non-acoustic methods ...

Brundage, Heather

2010-01-01T23:59:59.000Z

74

Underwater Sensor Network (UWSN) LabUnderwater Sensor Network (UWSN) Lab Demonstration of PCDemonstration of PC--based and DSPbased and DSP--basedbased  

E-Print Network (OSTI)

Underwater Sensor Network (UWSN) LabUnderwater Sensor Network (UWSN) Lab Demonstration--OFDM is one ultimate solution for highOFDM is one ultimate solution for high--datadata--raterate underwater acoustic communications!underwater acoustic communications! PC based implementationPC based implementation

Zhou, Shengli

75

Sound propagation around underwater seamounts  

E-Print Network (OSTI)

In the ocean, low frequency acoustic waves propagate with low attenuation and cylindrical spreading loss over long-ranges, making them an effective tool for underwater source localization, tomography, and communications. ...

Sikora, Joseph J., III

2009-01-01T23:59:59.000Z

76

Software Modems for Underwater Sensor Networks Raja Jurdak, Pedro Aguiar, Pierre Baldi, and Cristina Videira Lopes  

E-Print Network (OSTI)

Software Modems for Underwater Sensor Networks Raja Jurdak, Pedro Aguiar, Pierre Baldi acoustic hardware represent an obstacle for underwater sensor network deployment efforts. To address this issue, we propose underwater networks that rely on widely available speakers and microphones

Aguiar, Pedro M. Q.

77

An Underwater Network Testbed: Design, Implementation and Measurement  

E-Print Network (OSTI)

An Underwater Network Testbed: Design, Implementation and Measurement Zheng Peng, Jun-Hong Cui-Lab, an underwater acoustic sensor network lab testbed. Aqua-Lab consists of a water tank, a set of acoustic algorithms and protocols designed for underwater sensor networks. Categories and Subject Descriptors C.2.m

Wang, Bing

78

Wireless Underwater Communications  

Science Conference Proceedings (OSTI)

The depths of the oceans have a high potential for future industrial development and applications. Robotic autonomous systems will greatly depend on a reliable communications channel with operators and equipment either performing joint operations or ... Keywords: Acoustic communications, Channel modelling, Networking mechanisms, Underwater

J. Poncela; M. C. Aguayo; P. Otero

2012-06-01T23:59:59.000Z

79

Underwater wireless communications have witnessed major developments in recent years, especially in the last decade. While the first generation of applications involved just a single transmitter and receiver communicating at low bit-rates, nowadays un-  

E-Print Network (OSTI)

Underwater wireless communications have witnessed major developments in recent years, especially applications range from autonomous observation systems to cooperative missions between autonomous underwater layer for underwater networks. The underwater acoustic channel shows some unique characteristics

Stojanovic, Milica

80

Data muling over underwater wireless sensor networks using an autonomus underwater vehicle  

E-Print Network (OSTI)

Abstract — We present algorithms, systems, and experimental results for underwater data muling. In data muling a mobile agent interacts with static agents to upload, download, or transport data to a different physical location. We consider a system comprising an Autonomous Underwater Vehicle (AUV) and many static Underwater Sensor Nodes (USN) networked together optically and acoustically. The AUV can locate the static nodes using vision and hover above the static nodes for data upload. We describe the hardware and software architecture of this underwater system, as well as experimental data. Index Terms — Underwater sensor networks, AUV, visionbased navigation, underwater robotics.

Matthew Dunbabin; Peter Corke; Iuliu Vasilescu; Daniela Rus

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Detection of ultra high energy neutrinos with an underwater very large volume array of acoustic sensors: A simulation study  

E-Print Network (OSTI)

This thesis investigates the detection of ultra high energy (E > 1 EeV) cosmic neutrinos using acoustic sensors immersed in water. The method is based on the thermoacoustic model describing the production of microsecond bipolar acoustic pulses by neutrino-induced particle cascades. These cascades locally heat the medium which leads to rapid expansion and a short sonic pulse detectable in water with hydrophones over distances of several kilometres. This makes acoustic detection an approach complementary to todays optical Cerenkov and radio Cerenkov detectors, and could help to reduce the respective systematic uncertainties. In this work a complete simulation / reconstruction chain for a submarine acoustic neutrino telescope is developed, and the sensitivity of such a detector to a diffuse flux of ultra highenergy cosmic neutrinos is estimated.

Timo Karg

2006-08-15T23:59:59.000Z

82

Underwater cities  

NLE Websites -- All DOE Office Websites (Extended Search)

Underwater cities Name: hasinoff Location: NA Country: NA Date: NA Question: I have a student who is doing a project on underwater cities. What are the most important technical...

83

On the Impacts and Benefits of Implementing Full-Duplex Communications Links in an Underwater Acoustic Network  

E-Print Network (OSTI)

-duplex links requires the total system data capacity be divided between the generated channels, which can lead of sensor grids, ad hoc communications links to covert forces, or positive control of unmanned, forward-deployed weapons systems. However, the capacity limitations and extreme propagation delays of acoustic

Xie, Geoffrey

84

Design and Control of Autonomous Underwater Robots: A Survey  

Science Conference Proceedings (OSTI)

During the 1990s, numerous worldwide research and development activities have occurred in underwater robotics, especially in the area of autonomous underwater vehicles (AUVs). As the ocean attracts great attention on environmental issues and resources ... Keywords: autonomous underwater vehicles, underwater navigation and control, underwater robots

J. Yuh

2000-01-01T23:59:59.000Z

85

Fountain Codes and their Application to Broadcasting in Underwater Networks  

E-Print Network (OSTI)

Fountain Codes and their Application to Broadcasting in Underwater Networks: Performance Modeling aim in this paper is to study the performance of broadcasting al- gorithms for underwater acoustic to broad- casting in underwater networks. Our analysis allows us to find per- formance metrics

Rossi, Michele

86

Underwater Sensor Networking: Research Challenges and Potential Applications  

E-Print Network (OSTI)

Underwater Sensor Networking: Research Challenges and Potential Applications USC/ISI Technical, and underwater robotics. We identify research directions in short-range acoustic communications, MAC, time in applications today on the ground, underwater operations remain quite limited by comparison. Remotely controlled

Heidemann, John

87

Cooperative Localization for Autonomous Underwater Vehicles  

Science Conference Proceedings (OSTI)

This paper describes an algorithm for distributed acoustic navigation for Autonomous Underwater Vehicles (AUVs). Whereas typical AUV navigation systems utilize pre-calibrated arrays of static transponders, our work seeks to create a fully mobile network ... Keywords: autonomous underwater vehicles, cooperative navigation, mobile robotics, sensor networks

Alexander Bahr; John J. Leonard; Maurice F. Fallon

2009-06-01T23:59:59.000Z

88

Wireless Sensor Networks for Underwater Localization: A Survey  

E-Print Network (OSTI)

Autonomous Underwater Vehicles (AUVs) have widely deployed in marine investigation and ocean exploration in recent years. As the fundamental information, their position information is not only for data validity but also for many real-world applications. Therefore, it is critical for the AUV to have the underwater localization capability. This report is mainly devoted to outline the recent advancement of Wireless Sensor Networks (WSN) based underwater localization. Several classic architectures designed for Underwater Acoustic Sensor Network (UASN) are briefly introduced. Acoustic propagation and channel models are described and several ranging techniques are then explained. Many state-of-the-art underwater localization algorithms are introduced, followed by the outline of some

Sen Wang; Huosheng Hu

2012-01-01T23:59:59.000Z

89

1756 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 57, NO. 3, MAY 2008 Silent Positioning in Underwater  

E-Print Network (OSTI)

in Underwater Acoustic Sensor Networks Xiuzhen Cheng, Member, IEEE, Haining Shu, Student Member, IEEE, Qilian a silent positioning scheme termed UPS for underwater acoustic sensor networks. UPS relies on the time and provides location privacy at underwater vehicles/sensors whose locations need to be determined. To study

Cheng, Xiuzhen "Susan"

90

Handling Triple Hidden Terminal Problems for Multi-Channel MAC in Long-Delay Underwater  

E-Print Network (OSTI)

1 Handling Triple Hidden Terminal Problems for Multi-Channel MAC in Long-Delay Underwater Sensor-channel MAC problem in underwater acoustic sensor networks. To reduce hardware cost, only one acoustic transceiver is often preferred on every node. In a single-transceiver multi- channel long-delay underwater

Cui, Jun-Hong

91

Underwater sensor networking: Research challenges and potential applications  

E-Print Network (OSTI)

This report summarizes our research directions in underwater sensor networks. We highlight potential applications to off-shore oilfields for seismic monitoring, equipment monitoring, and underwater robotics. We identify research directions in short-range acoustic communications, MAC, time synchronization, and localization protocols for highlatency acoustic networks, long-duration network sleeping, and application-level data scheduling. 1

John Heidemann; Yuan Li; Affan Syed; Jack Wills; Wei Ye

2006-01-01T23:59:59.000Z

92

Communication protocols for underwater data collection using a robotic sensor network  

E-Print Network (OSTI)

We examine the problem of collecting data from an underwater sensor network using an autonomous underwater vehicle (AUV). The sensors in the network are equipped with acoustic modems that provide noisy, range-limited ...

Singh, Hanumant

2013-05-01T23:59:59.000Z

93

Underwater Glider System Study  

E-Print Network (OSTI)

Leonard, N. E. , “ONR Underwater Glider Systems Study GliderDavis. The Autonomous Underwater Glider Spray. IEEE Journalto the ONR Committee for Underwater Glider Systems Study,

2003-01-01T23:59:59.000Z

94

Research Challenges and Applications for Underwater Sensor Networking  

E-Print Network (OSTI)

This paper explores applications and challenges for underwater sensor networks. We highlight potential applications to off-shore oilfields for seismic monitoring, equipment monitoring, and underwater robotics. We identify research directions in shortrange acoustic communications, MAC, time synchronization, and localization protocols for high-latency acoustic networks, longduration network sleeping, and application-level data scheduling. We describe our preliminary design on short-range acoustic communication hardware, and summarize results of high-latency time synchronization.

John Heidemann; Wei Ye; Jack Wills; Affan Syed; Yuan Li

2006-01-01T23:59:59.000Z

95

Design and implementation of an underwater sound recording device  

SciTech Connect

To monitor the underwater sound and pressure waves generated by activities such as underwater blasting and pile driving, an autonomous system used to record underwater acoustic signals was designed. The device designed allows two hydrophones or other dynamic pressure sensors to be connected, filters out high frequency noise, has a gain that can be independently set for each sensor, and allows two hours of data to be collected. Two versions of the USR were created; one is submersible to a maximum depth of 300 m, and the other, although watertight, is not intended to be fully submersed. Tests were performed in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to the each component. These tests verified that the device performs as well as larger commercially available data acquisition systems, which are not suited for field use. A prototype of the device was used in a case study to investigate the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. The case study demonstrated that the device was able to tolerate being operated in harsh environments, making it a valuable tool for collecting field measurements.

Martinez, Jayson J.; Myers, Joshua R.; Carlson, Thomas J.; Deng, Zhiqun; Rohrer, John S.; Caviggia, Kurt A.; Woodley, Christa M.; Weiland, Mark A.

2011-09-01T23:59:59.000Z

96

IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 58, NO. 8, AUGUST 2010 4093 Localization in Underwater Dispersive  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 58, NO. 8, AUGUST 2010 4093 Localization in Underwater applications of time-frequency representations deal with the analysis of the underwater acoustic signals nonlinear effect at very low frequencies. That is, if we intend to establish an underwater communication

Paris-Sud XI, Université de

97

Towards automated design of MAC protocols for underwater wireless networks  

Science Conference Proceedings (OSTI)

We present a framework for the automated design of MAC protocols for underwater acoustic wireless networks. We formulate a protocol optimization problem in which the exchange of control packets is explicitly modeled. A protocol optimization program generates ... Keywords: automation, mac, network, wireless underwater protocol

Volkan Rodoplu; Amir Aminzadeh Gohari; Wei Tang

2008-09-01T23:59:59.000Z

98

Transformation elastodynamics and active exterior acoustic cloaking  

E-Print Network (OSTI)

This chapter consists of three parts. In the first part we recall the elastodynamic equations under coordinate transformations. The idea is to use coordinate transformations to manipulate waves propagating in an elastic material. Then we study the effect of transformations on a mass-spring network model. The transformed networks can be realized with "torque springs", which are introduced here and are springs with a force proportional to the displacement in a direction other than the direction of the spring terminals. Possible homogenizations of the transformed networks are presented, with potential applications to cloaking. In the second and third parts we present cloaking methods that are based on cancelling an incident field using active devices which are exterior to the cloaked region and that do not generate significant fields far away from the devices. In the second part, the exterior cloaking problem for the Laplace equation is reformulated as the problem of polynomial approximation of analytic functions. An explicit solution is given that allows to cloak larger objects at a fixed distance from the cloaking device, compared to previous explicit solutions. In the third part we consider the active exterior cloaking problem for the Helmholtz equation in 3D. Our method uses the Green's formula and an addition theorem for spherical outgoing waves to design devices that mimic the effect of the single and double layer potentials in Green's formula.

Fernando Guevara Vasquez; Graeme W. Milton; Daniel Onofrei; Pierre Seppecher

2011-05-06T23:59:59.000Z

99

Information-theoretic limits of dense underwater networks  

E-Print Network (OSTI)

Information-theoretic throughput scaling laws are analyzed in an underwater acoustic network with n regularly located nodes on a unit square, in which both bandwidth and received signal power can be severely limited. A ...

Shin, Won-Yong

100

The underwater radiance distribution problem  

E-Print Network (OSTI)

THE UNDERWATER RADIANCE DISTRIBUTION PROBLEM S. Q. DuntleyFunction of Depth in an Underwater Environment," which firsta Function of Depth in an Underwater Environment," which has

Duntley, Seibert Q

1959-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Autonomous Underwater Vehicle (AUV) path planning and adaptive on-board routing for adaptive rapid environmental assessment  

E-Print Network (OSTI)

In shallow water, a large part of underwater acoustic prediction uncertainties are induced by sub-meso-to-small scale oceanographic variabilities. Conventional oceanographic measurements for capturing such ocean-acoustic ...

Wang, Ding, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

102

Clear underwater vision  

E-Print Network (OSTI)

Underwater imaging is important for scientific research and technology, as well as for popular activities. We present a computer vision approach which easily removes degradation effects in underwater vision. We analyze the physical effects of visibility degradation. We show that the main degradation effects can be associated with partial polarization of light. We therefore present an algorithm which inverts the image formation process, to recover a good visibility image of the object. The algorithm is based on a couple of images taken through a polarizer at different orientations. As a by product, a distance map of the scene is derived as well. We successfully used our approach when experimenting in the sea using a system we built. We obtained great improvement of scene contrast and color correction, and nearly doubled

Yoav Y. Schechner; Nir Karpel

2004-01-01T23:59:59.000Z

103

Underwater wireless sensor networks: routing issues and future challenges  

Science Conference Proceedings (OSTI)

With the advancements of acoustic modem technology that supports better data rates with reliable communications, current research focuses on algorithms those can support such technology in a better way. During the last two decades, many protocols suggested ... Keywords: acoustic communicaitons, intermettent networks, routing protocols, underwater sensor networks

Muhammad Ayaz; Azween Abdullah

2009-12-01T23:59:59.000Z

104

Exploring underwater target detection by imaging polarimetry and correlation techniques  

E-Print Network (OSTI)

1 Exploring underwater target detection by imaging polarimetry and correlation techniques M *Corresponding author: ayman.al-falou@isen.fr Underwater target detection is investigated by combining active. This experimentally study illustrates the potential of polarization imaging for underwater target detection and opens

Paris-Sud XI, Université de

105

Color-Accurate Underwater Imaging using Perceptual Adaptive Illumination  

E-Print Network (OSTI)

Color-Accurate Underwater Imaging using Perceptual Adaptive Illumination Iuliu Vasilescu, Carrick, and ecosystem health and activity monitoring. Underwater robots are equipped with motor control for large scale transects but they lack sensors that enable capturing color-accurate underwater images. We present a method

Farritor, Shane

106

Underwater Mortgages  

E-Print Network (OSTI)

House prices have fallen approximately 30 % from their peak in 2006, accompanied by a level of defaults and foreclosures without precedent in the post-World War II era. Many homeowners have mortgages with principal amounts higher than the market value of their properties. In general, though, the rational default point is below the “underwater ” point where house price equals the remaining loan balance, and depends on prospects for future house price appreciation and borrower default costs. Housing market analysts often explain mortgage defaults as a consequence of life events such as divorce, illness, or job loss. No doubt, such events figure importantly in a borrower’s ability to repay a mortgage. However, except for unemployment, which varies with the business cycle, life events occur with unfortunate regularity. By contrast, mortgage default rates vary substantially over time. It is clear then that life events lead to defaults when they occur in combination with some other factor. It seems most likely that this other factor is a change in house prices. Default and foreclosure are costly for borrowers. They would rather avoid these expenses by selling their houses and prepaying their mortgages instead of defaulting. They can and will do so when house prices are increasing or flat. The default rate increases in periods when house prices have fallen, making mortgage prepayment through resale or refinancing difficult. Given the importance of falling house prices as a factor in defaults, it is natural to ask how far they must drop before it serves the borrower’s rational interest to strategically default, that is, to walk away from a mortgage even in the absence of a life event. A common answer is that house prices must fall to a point where the value of the house is less than the remaining loan balance, or when the house is “underwater ” (see Thaler 2010, for example). The map in Figure 1 estimates the incidence of underwater first-lien mortgages in 2000. We do not know the actual values of the underlying properties

Krainer; Stephen Leroy

2010-01-01T23:59:59.000Z

107

Underwater manipulator  

DOE Patents (OSTI)

Self-contained, waterproof, water-submersible, remote-controlled apparatus is provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer .+-.45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer .+-.10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Schrum, Phillip B. (Clairton, PA); Cohen, George H. (Pittsburgh, PA)

1993-01-01T23:59:59.000Z

108

Underwater manipulator  

DOE Patents (OSTI)

This invention is comprised of a self-contained, waterproof, water-submersible, remote-controlled apparatus provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer {plus_minus} 45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer {plus_minus} 10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Schrum, P.B.; Cohen, G.H.

1992-12-31T23:59:59.000Z

109

Underwater manipulator  

DOE Patents (OSTI)

Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer [plus minus]45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer [plus minus]10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Schrum, P.B.; Cohen, G.H.

1993-04-20T23:59:59.000Z

110

Software Modems for Underwater Sensor Networks  

E-Print Network (OSTI)

Abstract — The prohibitive monetary cost and high power consumption of existing acoustic hardware represent an obstacle for underwater sensor network deployment efforts. To address this issue, we propose underwater networks that rely on widely available speakers and microphones in electronic devices, coupled with software modems, to establish acoustic communication links. In this paper, we analytically and empirically explore the potential of this acoustic communication system for the underwater environment with a generic PC microphone as a receiver and with the Tmote Invent sensor module speaker as a transmitter. After waterproofing the components with elastic membranes that provide suitable coupling with the water, our experiments profile the hardware communication capability in a controlled aquatic environment. The medium profiling results expose the favorable frequencies of operation for the hardware, enabling us to design a software FSK modem. The experiments to evaluate the data transfer capability of our 8-frequency FSK software modem in the underwater channel yield an error-free channel capacity of 24 bps, and they also demonstrate that the system supports data rates up to at least 48 bps within a transmission range of 17 m. I.

Raja Jurdak; Pedro Aguiar; Pierre Baldi; Cristina Videira Lopes

2007-01-01T23:59:59.000Z

111

Hybrid CFx–Ag2V4O11 as a high-energy, power density cathode for application in an underwater acoustic microtransmitter  

SciTech Connect

This study demonstrates the excellent electrochemical performance of the hybrid carbon fluoride(CFx)/silver vanadium oxide(SVO)/graphene(G) cathode and its potential utilization in Acoustic Telemetry System Transmitter (ATST). The impedance increase issue caused by LiF formation from CFx is effectively addressed by the deposition of conductive silver metal from the reduction of SVO aided by the coexistence of graphene additive thus a prolonged operation voltage is observed with enhanced electronic conductivity throughout the whole discharge process. In particular, the hybrid shows capacity retention of {approx}462 mAhg-1 at 5C rate and 661 mAhg-1 at 1C rate. The peak current delivered from the as-designed hybrid cathode is improved compared with that of commercial Zn/Ag2O batteries suggesting the possibility of the further reduction on the size/weight of the micro batteries which is critical for the transmitters.

Meduri, Praveen; Chen, Honghao; Chen, Xilin; Xiao, Jie; Gross, Mark E.; Carlson, Thomas J.; Zhang, Jiguang; Deng, Zhiqun

2011-12-01T23:59:59.000Z

112

Experiments with Underwater Robot Localization and Tracking Peter Corke, Carrick Detweiler, Matthew Dunbabin, Michael Hamilton,Daniela Rus and Iuliu Vasilescu  

E-Print Network (OSTI)

Experiments with Underwater Robot Localization and Tracking Peter Corke, Carrick Detweiler, Matthew of underwater robot localization are compared. The first method is based on a geometric approach in which, and a comparison of acoustic and visual methods for underwater operation. I. INTRODUCTION Performing reliable

Hamilton, Michael P.

113

Multi-hop routing is order-optimal in underwater extended networks  

E-Print Network (OSTI)

Capacity scaling laws are analyzed in an underwater acoustic network with n regularly located nodes. A narrow-band model is assumed where the carrier frequency is allowed to scale as a function of n. In the network, we ...

Shin, Won-Yong

114

Capacity Scaling Laws for Underwater Networks  

E-Print Network (OSTI)

The underwater acoustic channel is characterized by a path loss that depends not only on the transmission distance, but also on the signal frequency. Signals transmitted from one user to another over a distance $l$ are subject to a power loss of $l^{-\\alpha}{a(f)}^{-l}$. Although a terrestrial radio channel can be modeled similarly, the underwater acoustic channel has different characteristics. The spreading factor $\\alpha$, related to the geometry of propagation, has values in the range $1 \\leq \\alpha \\leq 2$. The absorption coefficient $a(f)$ is a rapidly increasing function of frequency: it is three orders of magnitude greater at 100 kHz than at a few Hz. Existing results for capacity of wireless networks correspond to scenarios for which $a(f) = 1$, or a constant greater than one, and $\\alpha \\geq 2$. These results cannot be applied to underwater acoustic networks in which the attenuation varies over the system bandwidth. We use a water-filling argument to assess the minimum transmission power and optimum...

Lucani, Daniel E; Stojanovic, Milica

2009-01-01T23:59:59.000Z

115

Multicolor Underwater Imaging Techniques.  

E-Print Network (OSTI)

??Studies were conducted on multispectral polarimetric subtraction imaging techniques for underwater imaging that use a broadband light source. The main objective of this study was… (more)

Waggoner, Douglas Scott

2007-01-01T23:59:59.000Z

116

Routing Algorithms for Delay-insensitive and Delay-sensitive Applications in Underwater Sensor Networks  

E-Print Network (OSTI)

Underwater sensor networks consist of sensors and vehicles deployed to perform collaborative monitoring tasks over a given region. Underwater sensor networks will find applications in oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation, tactical surveillance, and mine reconnaissance. Underwater acoustic networking is the enabling technology for these applications. In this paper, an architecture for three-dimensional underwater sensor networks is considered, and a model characterizing the acoustic channel utilization efficiency is introduced, which allows investigating some fundamental characteristics of the underwater environment. In particular, the model allows setting the optimal packet size for underwater communications given monitored volume, density of the sensor network, and application requirements. Moreover, the problem of data gathering is investigated at the network layer by considering the cross-layer interactions between the routing functions and the characteristics of the underwater acoustic channel. Two distributed routing algorithms are introduced for delay-insensitive and delaysensitive applications. The proposed solutions allow each node to select its next hop, with the objective of minimizing the energy consumption taking the varying condition of the underwater channel and the different application requirements into account. The proposed routing solutions are shown to achieve the performance targets by means of simulation.

Dario Pompili; Tommaso Melodia; Ian F. Akyildiz

2006-01-01T23:59:59.000Z

117

Computer vision techniques for underwater navigation  

E-Print Network (OSTI)

Vision Techniques for Underwater Navigation A thesisand J. Amat. Positioning an underwater vehicle through imageand S. Feder. Autonomous Underwater Vehicle Navigation. MIT

Barngrover, Christopher M.

2010-01-01T23:59:59.000Z

118

Experiments with Underwater Robot Localization and Tracking  

E-Print Network (OSTI)

J. S. Feder, “Autonomous underwater vehicle navigation,” MITfor an autonomous underwater reef monitoring robot,” intechniques applied to an underwater vehicle,” in Proceedings

Corke, Peter; Detwiler, Carrick; Dunbabin, Matthew; Hamilton, Michael; Rus, Daniela; Vasilescu, Iuliu

2007-01-01T23:59:59.000Z

119

Effects of Channel Estimation Errors in OFDM-MIMO-Based Underwater Communications  

Science Conference Proceedings (OSTI)

State-of-the-art radio communication systems are in a large extent based on multi-carrier communication (OFDM) and multiple antennas (MIMO). In this paper the performance of such systems adapted to an underwater acoustic communication channel is assessed. ... Keywords: Acoustic communication, OFDM, MIMO

Jan Erik Hakegard; Knut Grythe

2009-05-01T23:59:59.000Z

120

Low probability of detection underwater acoustic ...  

Science Conference Proceedings (OSTI)

... increases significantly the data processing load. B. Temporal coherence: Signal coherence time The Doppler corrected impulse responses are ...

2009-03-06T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Autonomous Underwater Vehicle Measurements of Surface Wave Decay and Directional Spectra in the Marginal Sea Ice Zone  

Science Conference Proceedings (OSTI)

In March 2003 several autonomous underwater vehicle (AUV) missions were carried out under sea ice in the western Bellingshausen Sea. Data from the upward-looking acoustic Doppler current profiler (ADCP) on the “Autosub” AUV indicate a strongly ...

Daniel R. Hayes; Adrian Jenkins; Stephen McPhail

2007-01-01T23:59:59.000Z

122

Underwater Gliders: Recent Developments and Future Applications  

E-Print Network (OSTI)

Underwater Gliders: Recent Developments and Future Applications (Invited Paper) R. Bachmayer, N underwater vehicles, and in particular au- tonomous underwater gliders, represent a rapidly maturing of an underwater glider system for propulsion, control, communication and sensing. A typical glider operation

Leonard, Naomi

123

Underwater localization based on multicarrier waveforms  

E-Print Network (OSTI)

Abstract—In this paper, we investigate the problem of localizing an underwater sensor node based on message broadcasting from multiple surface nodes. With the time-of-arrival measurements from a DSP-based multicarrier modem, each sensor node localizes itself based on the travel time differences among multiple senders to the receiver. Using one-way message passing, such a solution can scalably accommodate a large number of nodes in a network. We present simulation results as well as preliminary testing results in a swimming pool and in a local lake. Surface buoys with GPS sensors self-localization via acoustic links I.

Patrick Carroll; Shengli Zhou; Hao Zhou; Jun-hong Cui; Peter Willett

2010-01-01T23:59:59.000Z

124

TIMEOPTIMAL CONTROL FOR UNDERWATER VEHICLES  

E-Print Network (OSTI)

TIME­OPTIMAL CONTROL FOR UNDERWATER VEHICLES M. Chyba #,1 N.E. Leonard #,1 E.D. Sontag ##,2 problems for a special class of controlled mechanical systems, underwater vehicles. Lie algebras associated­optimal trajectories. We apply the general theory to a model of an underwater vehicle and illustrate our results

Sontag, Eduardo

125

Autonomous Underwater Gliders Wood, Stephen  

E-Print Network (OSTI)

26 Autonomous Underwater Gliders Wood, Stephen Florida Institute of Technology United States underwater vehicles to perform ocean surveys. With these vehicles it is now possible for the scientist substances in the ocean such as chemicals from an underwater vent or toxic algae such as red tide

Wood, Stephen L.

126

Oxygen in Underwater Cave  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxygen in Underwater Cave Oxygen in Underwater Cave Name: Natalie Status: student Grade: 9-12 Location: HI Country: USA Date: Spring 2011 Question: Is it possible for there to be free oxygen in an underwater cave? If it is, then how does it work? Replies: Yes it is possible as I have personally experienced. If the cave roof rises to a level above the water, air dissolved in the water will slowly out gas until the water is at the same level at all places. A pocket of breathable air will form. In many caves the roof dips below water level in one place but it above it on both sides. Think of a U shaped tube where the bottom of the U is blocked by water. This is called a siphon and I have passed through many of these to find breathable air on the other side. R. W. "Bob" Avakian Oklahoma State Univ. Inst. of Technology

127

Acoustic waves in the atmosphere and ground generated by volcanic activity  

SciTech Connect

This paper reports an interesting sequence of harmonic tremor observed in the 2011 eruption of Shinmoe-dake volcano, southern Japan. The main eruptive activity started with ashcloud forming explosive eruptions, followed by lava effusion. Harmonic tremor was transmitted into the ground and observed as seismic waves at the last stage of the effusive eruption. The tremor observed at this stage had unclear and fluctuating harmonic modes. In the atmosphere, on the other hand, many impulsive acoustic waves indicating small surface explosions were observed. When the effusion stopped and the erupted lava began explosive degassing, harmonic tremor started to be transmitted also to the atmosphere and observed as acoustic waves. Then the harmonic modes became clearer and more stable. This sequence of harmonic tremor is interpreted as a process in which volcanic degassing generates an open connection between the volcanic conduit and the atmosphere. In order to test this hypothesis, a laboratory experiment was performed and the essential features were successfully reproduced.

Ichihara, Mie; Lyons, John; Oikawa, Jun; Takeo, Minoru [Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Instituto Geofisico, Escuela Politecnica Nacional, Ladron de Guevara E11-253, Aptdo 2759, Quito (Ecuador); Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

2012-09-04T23:59:59.000Z

128

Vocalization characteristics of North Atlantic right whale surface active groups in the calving habitat, southeastern United States  

Science Conference Proceedings (OSTI)

Passive acoustic surveys were conducted to assess the vocal behavior of North Atlantic right whales (Eubalaena glacialis) in the designated critical calving habitat along the shallow coastal waters of southeastern United States. Underwater vocalizations were recorded using autonomous buoys deployed in close proximity to surface active groups (SAGs). Nine main vocalization types were identified with manual inspection of spectrograms

Vasilis Trygonis; Edmund Gerstein; Stephen McCulloch

2013-01-01T23:59:59.000Z

129

Underwater cladding with laser beam and plasma arc welding  

SciTech Connect

Two welding processes, plasma arc (transferred arc) (PTA) and laser beam, were investigated to apply cladding to austenitic stainless steels and Inconel 600. These processes have long been used to apply cladding layers , but the novel feature being reported here is that these cladding layers were applied underwater, with a water pressure equivalent to 24 m (80 ft). Being able to apply the cladding underwater is very important for many applications, including the construction of off-shore oil platforms and the repair of nuclear reactors. In the latter case, being able to weld underwater eliminates the need for draining the reactor and removing the fuel. Welding underwater in reactors presents numerous challenges, but the ability to weld without having to drain the reactor and remove the fuel provides a huge cost savings. Welding underwater in reactors must be done remotely, but because of the radioactive corrosion products and neutron activation of the steels, remote welding would also be required even if the reactor is drained and the fuel removed. In fact, without the shielding of the water, the remote welding required if the reactor is drained might be even more difficult than that required with underwater welds. Furthermore, as shall be shown, the underwater welds that the authors have made were of high quality and exhibit compressive rather than tensile residual stresses.

White, R.A.; Fusaro, R.; Jones, M.G.; Solomon, H.D. [General Electric Corporate Research and Development Center, Schenectady, NY (United States); Milian-Rodriguez, R.R. [GE Nuclear Energy, San Jose, CA (United States)

1997-01-01T23:59:59.000Z

130

Underwater Sensor Networks: Applications, Advances, and Challenges  

E-Print Network (OSTI)

Underwater Sensor Networks: Applications, Advances, and Challenges By John Heidemann1 , Milica- mentation of underwater wireless sensor networks. We summarize key applications and the main phenomena hardware, testbeds, and simulation tools available to the research community. Keywords: underwater

Heidemann, John

131

Intelligent Planning for Autonomous Underwater Vehicles  

E-Print Network (OSTI)

Intelligent Planning for Autonomous Underwater Vehicles Zeyn Saigol January 31, 2007 Supervisors Underwater Vehicles Classical planning systems Problem specification Markov Decision Processes 2 / 10 #12 in relaxing these planning under uncertainty Application area: Autonomous Underwater Vehicles (AUVs) used

Yao, Xin

132

Underwater noise caused by snapping shrimp  

E-Print Network (OSTI)

E. 0. ~ulbert,,~~An Underwater Sound of Natural Qrigin,!! J.Sect ion, Feb. 3, 1943. UNDERWATER SOUN~SOF OLOG l CALOF CERTAl N Bl OLOGl CAL UNDERWATER SOUND ON 'THE EAST COAST

University of California, Division of War Research at the U.S. Navy Electronics Laboratory,

1946-01-01T23:59:59.000Z

133

Networking support for underwater wireless networks.  

E-Print Network (OSTI)

?? Underwater wireless networks provide many opportunities for exploration, environmental monitoring, and military applications. Future growth of underwater networks seems promising as much of the… (more)

Kredo, Kurtis B., II

2010-01-01T23:59:59.000Z

134

NEMO-\\onde: a submarine station for real-time monitoring of acoustic background installed at 2000 m depth in the Mediterranean Sea  

E-Print Network (OSTI)

The NEMO (NEutrino Mediterranean Observatory) Collaboration installed, 25 km E offshore the port of Catania (Sicily) at 2000 m depth, an underwater laboratory to perform long-term tests of prototypes and new technologies for an underwater high energy neutrino km$^3$-scale detector in the Mediterranean Sea. In this framework the collaboration deployed and successfully operated for about two years, starting form January 2005, an experimental apparatus for on-line monitoring of deep-sea noise. The station was equipped with 4 hydrophones and it is operational in the range 30 Hz - 43 kHz. This interval of frequencies matches the range suitable for the proposed acoustic detection technique of high energy neutrinos. Hydrophone signals were digitized underwater at 96 kHz sampling frequency and 24 bits resolution. A custom software was developed to record data on high resolution 4-channels digital audio file. This paper deals with the data analysis procedure and first results on the determination of sea noise sound pressure density curves. The stored data library, consisting of more than 2000 hours of recordings, is a unique tool to model underwater acoustic noise at large depth, to characterise its variations as a function of environmental parameters, biological sources and human activities (ship traffic, ...), and to determine the presence of cetaceans in the area.

The NEMO Collaboration; L. Cosentino; M. Favetta; G. Larosa; G. Pavan; D. J. Romeo; S. Privitera; F. Speziale

2008-04-17T23:59:59.000Z

135

Challenges: Building Scalable and Distributed Underwater Wireless Sensor Networks (UWSNs) for Aquatic Applications  

E-Print Network (OSTI)

Large-scale Underwater Wireless Sensor Network (UWSN) is a novel networking paradigm to explore the uninhabited and complex oceans. However, the characteristics of UWSNs, such as huge propagation delay, floating node mobility, and limited acoustic link capacity, are significantly different from ground-based wireless sensor networks and existing small scale Underwater Acoustic Networks (UANs). The novel networking paradigm poses inter-disciplinary challenges that will require new technological solutions. In particular, in this technical report we adopt a top-down approach to explore the research challenges in UWSN design. Along the layered protocol stack, we roughly go down from the top application layer to the bottom physical layer. At each layer, a set of new design intricacies are studied. The conclusion is that building scalable and distributed UWSNs is a challenge that must be answered by inter-disciplinary efforts of acoustic communications, signal processing and mobile acoustic network protocol design. I.

Jun-hong Cui; Jiejun Kong; Mario Gerla; Shengli Zhou

2005-01-01T23:59:59.000Z

136

Data collection, storage, and retrieval with an underwater sensor network  

E-Print Network (OSTI)

In this paper we present a novel platform for underwater sensor networks to be used for long-term monitoring of coral reefs and fisheries. The sensor network consists of static and mobile underwater sensor nodes. The nodes communicate point-to-point using a novel high-speed optical communication system integrated into the TinyOS stack, and they broadcast using an acoustic protocol integrated in the TinyOS stack. The nodes have a variety of sensing capabilities, including cameras, water temperature, and pressure. The mobile nodes can locate and hover above the static nodes for data muling, and they can perform network maintenance functions such as deployment, relocation, and recovery. In this paper we describe the hardware and software architecture of this underwater sensor network. We then describe the optical and acoustic networking protocols and present experimental networking and data collected in a pool, in rivers, and in the ocean. Finally, we describe our experiments with mobility for data muling in this network.

I. Vasilescu; K. Kotay; D. Rus; M. Dunbabin; P. Corke

2005-01-01T23:59:59.000Z

137

A Small Submarine Robot for Experiments in Underwater Sensor Networks  

E-Print Network (OSTI)

The Development of Autonomous Underwater Vehicles (AUVs); AA Solar Powered Autonomous Underwater Vehi- cle System,The Phoenix Autonomous Underwater Vehicle, chapter 13, AI-

V. Bokser; C. Oberg; G. Sukhatme; A. Requicha

2004-01-01T23:59:59.000Z

138

Underwater Lighting by Submerged Lasers and Incandescent Sources  

E-Print Network (OSTI)

Techniques for long- range underwater photography usingon Resolving Power in Underwater Photography," J. Opt. Soc.A. R. , Tyler, J. E. , "Underwater Photometer," J. Opt. Soc.

Duntley, Seibert Q

1971-01-01T23:59:59.000Z

139

NW-MILO Acoustic Data Collection  

SciTech Connect

There is an enduring requirement to improve our ability to detect potential threats and discriminate these from the legitimate commercial and recreational activity ongoing in the nearshore/littoral portion of the maritime domain. The Northwest Maritime Information and Littoral Operations (NW-MILO) Program at PNNL’s Coastal Security Institute in Sequim, Washington is establishing a methodology to detect and classify these threats - in part through developing a better understanding of acoustic signatures in a near-shore environment. The purpose of the acoustic data collection described here is to investigate the acoustic signatures of small vessels. The data is being recorded continuously, 24 hours a day, along with radar track data and imagery. The recording began in August 2008, and to date the data contains tens of thousands of signals from small vessels recorded in a variety of environmental conditions. The quantity and variety of this data collection, with the supporting imagery and radar track data, makes it particularly useful for the development of robust acoustic signature models and advanced algorithms for signal classification and information extraction. The underwater acoustic sensing system is part of a multi-modal sensing system that is operating near the mouth of Sequim Bay. Sequim Bay opens onto the Straight of Juan de Fuca, which contains part of the border between the U.S. and Canada. Table 1 lists the specific components used for the NW-MILO system. The acoustic sensor is a hydrophone permanently deployed at a mean depth of about 3 meters. In addition to a hydrophone, the other sensors in the system are a marine radar, an electro-optical (EO) camera and an infra-red (IR) camera. The radar is integrated with a vessel tracking system (VTS) that provides position, speed and heading information. The data from all the sensors is recorded and saved to a central server. The data has been validated in terms of its usability for characterizing the signatures of small vessels. The sampling rate of 8 kHz and low pass filtering to 2 kHz results in an alias-free signal in the frequency band that is appropriate for small vessels. Calibration was performed using a Lubell underwater speaker so that the raw data signal levels can be converted to sound pressure. Background noise is present due to a nearby pump and as a result of tidal currents. More study is needed to fully characterize the noise, but it does not pose an obstacle to using the acoustic data for the purposes of vessel detection and signature analysis. The detection range for a small vessel was estimated using the calibrated voltage response of the system and a cylindrical spreading model for transmission loss. The sound pressure of a typical vessel with an outboard motor was found to be around 140 dB mPa, and could theoretically be detected from 10 km away. In practical terms, a small vessel could reliably be detected from 3 - 5 km away. The data is archived in netCDF files, a standard scientific file format that is "self describing". This means that each data file contains the metadata - timestamps, units, origin, etc. - needed to make the data meaningful and portable. Other file formats, such as XML, are also supported. A visualization tool has been developed to view the acoustic data in the form of spectrograms, along with the coincident radar track data and camera images.

Matzner, Shari; Myers, Joshua R.; Maxwell, Adam R.; Jones, Mark E.

2010-02-17T23:59:59.000Z

140

Underwater Gas Expansion and Deflagration  

E-Print Network (OSTI)

The underwater combustion of a propane-air mixture in an acrylic cylinder is captured on video from multiple angles. This experiment is designed to provide visual data and pressure time-histories for future CFD validation studies.

Jones, Van; Gilbert, John; McCue-Weil, Leigh

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Seismic Imaging of UXO-Contaminated Underwater Sites (Interim Report)  

E-Print Network (OSTI)

Imaging of UXO-Contaminated Underwater Sites” Roland GrittoImaging of UXO-Contaminated Underwater Sites” over the first

Gritto, Roland; Korneev, Valeri; Nihei, Kurt; Johnson, Lane

2004-01-01T23:59:59.000Z

142

Bowhead whale acoustic activity in the southeast Beaufort Sea during late summer 2008–2010  

Science Conference Proceedings (OSTI)

Autonomous passive acoustic recorders were deployed to record sounds of bowhead whales (Balaena mysticetus) in the southeast Beaufort Sea for periods of 30–55 days during the late summer

Russell A. Charif; Ashakur Rahaman; Charles A. Muirhead; Ann M. Warde; James Hall; Cynthia Py?; Christopher W. Clark

2013-01-01T23:59:59.000Z

143

www.postersession.com Autonomous Underwater Vehicles of the Underwater Technology Laboratory  

E-Print Network (OSTI)

printed by www.postersession.com Autonomous Underwater Vehicles of the Underwater Technology at depths to 6000 meters. The system will comprise of four key components: 1) an autonomous underwater vehicle (AUV), 2) an underwater refueling and information exchange station, 3) an oceanographic mooring

Wood, Stephen L.

144

A method for numerical representation of arbitrary boundaries in acoustic wavefront propagation.  

Science Conference Proceedings (OSTI)

An enhancement to the application of a wavefront propagation algorithm for underwater acoustics based on the level set method is presented. The presence of discontinuities in the phase space at reflecting boundaries requires the use of specialized differencing techniques to prevent oscillations in the computed solutions of the acoustic phase. A weighted essentially non?oscillatory method is applied for this purpose

Sheri Martinelli

2011-01-01T23:59:59.000Z

145

Autonomous Underwater Vehicle–Based Hydrographic Sampling  

Science Conference Proceedings (OSTI)

An autonomous underwater vehicle (AUV), the U.S. Navy’s Large Diameter Unmanned Underwater Vehicle (LDUUV), was used as a stable platform for rapid, repeated, near-synoptic CTD measurements of estuarine variability in Narragansett Bay. Surveys ...

Edward R. Levine; Donald N. Connors; Richard R. Shell; Robert C. Hanson

1997-12-01T23:59:59.000Z

146

Path planning methods for Autonomous Underwater Vehicles  

E-Print Network (OSTI)

From naval operations to ocean science missions, the importance of autonomous vehicles is increasing with the advances in underwater robotics technology. Due to the dynamic and intermittent underwater environment and the ...

Yi?it, Konuralp

2011-01-01T23:59:59.000Z

147

Full-duplex underwater networking using CDMA .  

E-Print Network (OSTI)

??Establishing a full-duplex underwater network, researching and applying a CDMA protocol to this network, providing a recommendation for a full-duplex underwater network and providing recommendations… (more)

Bektas, Kurtulus

2004-01-01T23:59:59.000Z

148

Reliability of underwater hearing thresholds in pinnipeds  

E-Print Network (OSTI)

Reliability of underwater hearing thresholds in pinnipeds Brandon L. Southall Long Marine@ucsc.edu Abstract: Repeated measures of low-frequency underwater hearing sensi- tivity in individuals of three and certain testing parameters (e.g., equipment and research personnel), measured underwater hearing

Reichmuth, Colleen

149

Underwater Vehicles for Deep Ocean Exploration  

E-Print Network (OSTI)

1 Underwater Vehicles for Deep Ocean Exploration Louis L. Whitcomb Ph.D. Associate Professor Kaohsiung, Taiwan, R.O.C. March 8, 2003 Outline · Introduction to Underwater Robotics · Johns Hopkins University Research Vehicle: JHU ROV · Research in Underwater Vehicle Navigation: ­ DVLNAV Navigation Program

Whitcomb, Louis L.

150

Three-dimensional ocean chlorophyll distributionsfrom underwater  

E-Print Network (OSTI)

Three-dimensional ocean chlorophyll distributionsfrom underwater serial-sectioned fluorescence images Andrew W. Palowitch and Jules S. Jaffe An underwater optical serial-sectioning technique that the underwater optical serial- sectioning technique is practical for in situ determination and analysis

Jaffe, Jules

151

UNDERWATER PAINT MARKING OF PORPOISES1  

E-Print Network (OSTI)

UNDERWATER PAINT MARKING OF PORPOISES1 Identification of individual animals has always been underwater. Applica- tion of these paints was easiest by pressurized spray. We experimented with spray. Paint bounced off most hard-surface materials before it could set underwater, unlike human or porpoise

152

Advances and Trends of Bionic Underwater Propulsors  

Science Conference Proceedings (OSTI)

In recent twenty years, tens of the bionic underwater prototype propulsors which imitate aquatic animals have been invented. The bionic principles hand classification of bionic propulsors were presented firstly. The main advance of the bionic propulsors ... Keywords: Bionic underwater propulsor, fish robot, undulation fin, neural control, underwater vehicle

Daibing Zhang; K. H. Low; Haibin Xie; Lincheng Shen

2009-05-01T23:59:59.000Z

153

On wormhole attacks in underwater sensor networks: A two-tier localization approach  

E-Print Network (OSTI)

Under-Water Sensor Network (UWSN) is a novel networking paradigm to explore the uninhabited oceans. However, the characteristics of this new network, such as huge propagation delay, floating node mobility, and limited acoustic link capacity, are significantly different from land-based sensor networks. In this paper we show that underwater denial-of-service attack imposes great threats to any UWSN. Without proper countermeasures, underwater sensor networking is a mission impossible. We propose a localization based approach to answer the challenge. In our design, DUB and DDB, a pair of efficient single-round distance measuring schemes, are critical building blocks to realize our approach inspite of constrained node capability and floating node mobility. In addition, to cope with low/medium node mobiltiy, we propose a two-tier localization scheme to identify short-range wormholes instantly, and long-haul wormholes within a limited latency. Our simulation and implementation confirm the effectiveness of our design. I.

Jiejun Kong; Zhengrong Ji; Weichao Wang; Mario Gerla; Rajive Bagrodia

2004-01-01T23:59:59.000Z

154

Divergence-Free Spatial Velocity Flow Field Interpolator for Improving Measurements from ADCP-Equipped Small Unmanned Underwater Vehicles  

Science Conference Proceedings (OSTI)

Applying a two-dimensional (2D) divergence-free (DF) interpolation to a one-person deployable unmanned underwater vehicle’s (UUV) noisy moving-vessel acoustic Doppler current profiler (MV-ADCP) measurements improves the results and increases the ...

Jamie MacMahan; Ross Vennell; Rick Beatson; Jenna Brown; Ad Reniers

2012-03-01T23:59:59.000Z

155

UNDERWATER COATINGS FOR CONTAMINATION CONTROL  

SciTech Connect

The Idaho National Laboratory (INL) deactivated several aging nuclear fuel storage basins. Planners for this effort were greatly concerned that radioactive contamination present on the basin walls could become airborne as the sides of the basins became exposed during deactivation and allowed to dry after water removal. One way to control this airborne contamination was to fix the contamination in place while the pool walls were still submerged. There are many underwater coatings available on the market for marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives were easily applied and adhered well to the substrates (pool wall materials) found in INL fuel pools. Lab-scale experiments were conducted by applying fourteen different commercial underwater coatings to four substrate materials representative of the storage basin construction materials, and evaluating their performance. The coupons included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The evaluation criteria included ease of application, adherence to the four surfaces of interest, no change on water clarity or chemistry, non-hazardous in final applied form and be proven in underwater applications. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected from the underwater coatings tested for application to all four pools. Divers scrubbed loose contamination off the basin walls and floors using a ship hull scrubber and vacuumed up the sludge. The divers then applied the coating using a special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pools with no detectable airborne contamination releases.

Julia L. Tripp; Kip Archibald; Ann Marie Phillips; Joseph Campbell

2004-02-01T23:59:59.000Z

156

NEMO: A Project for a km$^3$ Underwater Detector for Astrophysical Neutrinos in the Mediterranean Sea  

E-Print Network (OSTI)

The status of the project is described: the activity on long term characterization of water optical and oceanographic parameters at the Capo Passero site candidate for the Mediterranean km$^3$ neutrino telescope; the feasibility study; the physics performances and underwater technology for the km$^3$; the activity on NEMO Phase 1, a technological demonstrator that has been deployed at 2000 m depth 25 km offshore Catania; the realization of an underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).

I. Amore; for the NEMO Collaboration

2007-09-25T23:59:59.000Z

157

Trajectory Design and Implementation for Multiple Autonomous Underwater Vehicles Based on Ocean Model Predictions  

E-Print Network (OSTI)

for Multiple Autonomous Underwater Vehicles Based on OceanAUVs) • Autonomous Underwater Vehicles Evolving ocean

2009-01-01T23:59:59.000Z

158

Building Underwater Ad-Hoc Networks and Sensor Networks for Large Scale Real-Time Aquatic Applications  

E-Print Network (OSTI)

Large-scale Underwater Ad-hoc Networks (UANET) and Underwater Sensor Networks (UWSN) are novel networking paradigms to explore the uninhabited oceans. However, the characteristics of these new networks, such as huge propagation delay, floating node mobility, and limited acoustic link capacity, are significantly different from ground-based mobile ad-hoc networks (MANET) and wireless sensor networks (WSN). In this paper we adopt a top-down approach to explore the new research subject. We at first show a new practical application scenario that cannot be addressed by existing technology and hence demands the advent of the UANET and UWSN. Then along the layered protocol stack, we go down from the top application layer to the bottom physical layer. At each layer we show a set of new design challenges. We conclude that UANET and UWSN are challenges that must be answered by inter-disciplinary efforts of acoustic communication, signal processing and mobile acoustic network protocol design.

Jiejun Kong; Jun-hong Cui; Dapeng Wu; Mario Gerla

2005-01-01T23:59:59.000Z

159

Underwater Visual Acuity of Florida Manatees (Trichechus manatus latirostris)  

E-Print Network (OSTI)

equivalent aerial and underwater diurnal acuity. Science,S. , & Blue, J. (1999). The underwater audiogram of the WestR. F. (1971). Aerial and underwater visual acuity in the

Bauer, Gordon B.; Colbert, Debborah E.; Gaspard III, Joseph C.; Littlefield, Brandie; Fellner, Wendi

2003-01-01T23:59:59.000Z

160

Applications of Underwater Technology on Underwater Archaeology:The Search for Underwater Cultural Heritage in Peng-Hu Sea Area.  

E-Print Network (OSTI)

??The purpose of this paper is to investigate the survey strategy for marine archaeology using modern underwater survey and identification instruments and techniques on Peng-Hu… (more)

Chen, Wei-Cheng

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Experiments with Cooperative Control of Underwater Robots  

E-Print Network (OSTI)

In this paper we describe cooperative control algorithms for robots and sensor nodes in an underwater environment. Cooperative navigation is defined as the ability of a coupled system of autonomous robots to pool their resources to achieve long-distance navigation and a larger controllability space. Other types of useful cooperation in underwater environments include: exchange of information such as data download and retasking; cooperative localization and tracking; and physical connection (docking) for tasks such as deployment of underwater sensor networks, collection of nodes, and rescue of damaged robots. We present experimental results obtained with an underwater system that consists of two very different robots and a number of sensor network modules. We present the hardware and software architecture of this underwater system. We then describe various interactions between the robots and sensor nodes and between the two robots, including cooperative navigation. Finally, we describe our experiments with this underwater system and present data. 1

Matthew Dunbabin; Iuliu Vasilescu; Peter Corke; Daniela Rus

2008-01-01T23:59:59.000Z

162

TECHNOLOGY DEMONSTRATION UNDERWATER HYDROLASING PHASE 0 & 1 & 2 TECHNICAL REPORT  

Science Conference Proceedings (OSTI)

From September 10 through December 17th, 2003, S.A.Robotics executed Phases 0, I, and II of the Technology Demonstration - Underwater Hydrolasing. Phase 0 was performed at the S.A.Robotics facility in Loveland, Colorado, while Phases I and II were performed at the Hanford K-Basin East Site. The purpose of the demonstrations was to show (1) underwater hydrolasing is a feasible method of removing contaminated concrete underwater to a required depth, (2) the hydrolasing head could be controlled during operation, (3) the depth of contamination in the concrete structure could be accurately measured, and (4) a characterization of the waste stream during hydrolasing activities could be recorded. Video monitoring was also used during all demonstrations. All phases of the demonstration were completed and deemed a success by both the observers and the demonstration team. Single and multiple passes were made using variable cutting rates, different stand-off distances were tested, and stationary cuts were executed. Hot and cold hyrdolasing was performed with radiological and depth scans of the affected surfaces. Specially designed equipment was installed and operated within the contaminated environment of 100-K East Basin. Separate results are documented below by phase. The Phase II radiological demonstration was performed to determine the feasibility of underwater hydrolasing technology for decontamination of the DOE spent fuel basins at Hanford 100-K area. This project demonstration was conducted at 105 KE Basin with the expectation that, once proven, this technology can be implemented at Hanford and other DOE sites.

CHRONISTER, G.B.

2005-06-08T23:59:59.000Z

163

State Estimation Strategies for Autonomous Underwater Vehicle Fish Tracking Applications.  

E-Print Network (OSTI)

??As the largest unexplored area on earth, the underwater world has unlimited at traction to marine scientists. Due to the complexity of the underwater environment… (more)

Zhou, Jun Jay

2008-01-01T23:59:59.000Z

164

Intelligent deployment strategies for passive underwater sensor networks.  

E-Print Network (OSTI)

??Passive underwater sensor networks are often used to monitor a general area of the ocean, a port or military installation, or to detect underwater vehicles… (more)

Golen, Erik; Yuan, B; Shenoy, N

2009-01-01T23:59:59.000Z

165

Design of small, low-cost, underwater fin manipulator.  

E-Print Network (OSTI)

??This thesis details the development of a small, low cost, underwater manipulator for use on the XAUV. At this time, there are no cheap underwater… (more)

Roberts, Megan Johnson

2008-01-01T23:59:59.000Z

166

Implementation of a wireless underwater video link  

E-Print Network (OSTI)

Autonomous underwater vehicles (AUVs) are increasingly being considered for remotely supervised missions, primarily for routine subsea inspection tasks currently performed by tethered remotely operated vehicles (ROVs). ...

Morash, James Paul

2008-01-01T23:59:59.000Z

167

Underwater survival story presents physics puzzle  

NLE Websites -- All DOE Office Websites (Extended Search)

0213sea 07022013 High Resolution Image LLNL physicist Maxim Umansky recently performed a physics analysis of an underwater survival story off the Nigerian coast. Umansky, an...

168

Iterative equalization and decoding applied to underwater acoustic communication  

E-Print Network (OSTI)

absolute phase error versus iter- ation. (d) Number of bitCMP estimation are done iter- atively, in conjunction withAPP estimates ? (i) . If i = N iter , then the sym- bol APP

Sifferlen, James F.

2008-01-01T23:59:59.000Z

169

Lorentz actuators for turbulence control and underwater acoustic communications  

E-Print Network (OSTI)

Lorentz actuator dynamics in a fluid are governed by the fundamental principles of electromagnetism and hydrodynamics and have several potential applications in the marine field. Two areas of interest where improvements ...

Sura, Daniel A

2005-01-01T23:59:59.000Z

170

Artificial Bubble Cloud Targets for Underwater Acoustic Remote Sensing  

Science Conference Proceedings (OSTI)

This article describes a technique that uses polymer additives to suspend air bubbles to form stable artificial bubble clouds. The results presented include the range of polymer concentrations for an effective bubble suspension; the void fraction,...

Paul A. Hwang; Ronald A. Roy; Lawrence A. Crum

1995-12-01T23:59:59.000Z

171

In-Situ Characterization of Underwater Radioactive Sludge  

Science Conference Proceedings (OSTI)

A fundamental requirement underpinning safe clean-up technologies for legacy spent nuclear fuel (SNF) ponds, pools and wet silos is the ability to characterize the radioactive waste form prior to retrieval. The corrosion products resulting from the long term underwater storage of spent nuclear fuel, reactor components and reprocessing debris present a major hazard to facility decontamination and decommissioning in terms of their radioactive content and physical / chemical reactivity. The ability to perform in-situ underwater non-destructive characterization of sludge and debris in a safe and cost-effective manner offers significant benefits over traditional destructive sampling methods. Several techniques are available for underwater measurements including (i) Gross gamma counting, (ii) Low-, Medium- and High- Resolution Gamma Spectroscopy, (iii) Passive neutron counting and (iv) Active Neutron Interrogation. The optimum technique depends on (i) the radioactive inventory (ii) mechanical access restrictions for deployment of the detection equipment, interrogation sources etc. (iii) the integrity of plant records and (iv) the extent to which Acceptable Knowledge which may be used for 'fingerprinting' the radioactive contents to a marker nuclide. Prior deployments of underwater SNF characterization equipment around the world have been reviewed with respect to recent developments in gamma and neutron detection technologies, digital electronics advancements, data transfer techniques, remote operation capabilities and improved field ruggedization. Modeling and experimental work has been performed to determine the capabilities, performance envelope and operational limitations of the future generation of non-destructive underwater sludge characterization techniques. Recommendations are given on the optimal design of systems and procedures to provide an acceptable level of confidence in the characterization of residual sludge content of legacy wet storage facilities such that retrieval and repackaging of SNF sludges may proceed safely and efficiently with support of the regulators and the public. (author)

Simpson, A.P.; Clapham, M.J.; Swinson, B. [Pajarito Scientific Corp., Santa Fe, NM (United States)

2008-07-01T23:59:59.000Z

172

Underwater Coatings for Contamination Control  

Science Conference Proceedings (OSTI)

The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included 1) Test Area North (TAN-607) with epoxy painted concrete walls; 2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; 3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and 4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55oF to 80oF dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: · Be easy to apply · Adhere well to the four surfaces of interest · Not change or have a negative impact on water chemistry or clarity · Not be hazardous in final applied form · Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected to be applied by divers after scrubbing loose contamination off the basin walls and floors using a ship hull scrubber and vacuuming up the sludge. A special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pool with no airborne contamination problems.

Julia L. Tripp; Kip Archibald; Ann-Marie Phillips; Joseph Campbell

2004-02-01T23:59:59.000Z

173

Compact acoustic refrigerator  

DOE Patents (OSTI)

This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

Bennett, G.A.

1991-12-31T23:59:59.000Z

174

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

Bennett, G.A.

1992-11-24T23:59:59.000Z

175

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

Bennett, Gloria A. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

176

Acoustic imaging system  

DOE Patents (OSTI)

An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

Smith, Richard W. (Richland, WA)

1979-01-01T23:59:59.000Z

177

Platform effects on optical variability and prediction of underwater visibility  

E-Print Network (OSTI)

Platform effects on optical variability and prediction of underwater visibility Grace Chang,1, specifically the breakdown of stratification from mixing by the hull of R/P FLIP. Modeled underwater radiance Successful, rapid identification of underwater tar- gets and accurate underwater imaging are critical

You, Yu

178

Underwater Vehicles hal-00733797,version1-19Sep2012  

E-Print Network (OSTI)

Underwater Vehicles hal-00733797,version1-19Sep2012 Author manuscript, published in "Underwater Vehicles (2009) 525-538" #12;hal-00733797,version1-19Sep2012 #12;Underwater Vehicles Edited by Alexander V from: publication@intechweb.org First published January 2009 Printed in Croatia Underwater Vehicles

Paris-Sud XI, Université de

179

Automatic Underwater Image Pre-Processing Stephane Bazeille(1)  

E-Print Network (OSTI)

Automatic Underwater Image Pre-Processing St´ephane Bazeille(1) , Isabelle Quidu(1) , Luc Jaulin(1 Cedex 9 FRANCE (2) Thales Underwater Systems S.A S. Route de Sainte Anne du Portzic Site Amiral Nomy CS for underwater image restoration. Because of specific transmission properties of light in the water, underwater

Paris-Sud XI, Université de

180

Underwater Augmented Reality Game using the DOLPHYN Abdelkader Bellarbi2  

E-Print Network (OSTI)

Underwater Augmented Reality Game using the DOLPHYN Abdelkader Bellarbi2 , Christophe Domingues1 technologies. With the extension of Internet to underwater applications, the innovative character, such as the mouse, to underwater uses [1]. The Dolphyn is an underwater-computerized display system with various

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Upper ocean processes observed by underwater gliders in the California Current System  

E-Print Network (OSTI)

region using autonomous underwater gliders during fall of73 Chapter 4 Underwater gliders reveal rapid arrivaland M. D. Ohman (2011), Underwater gliders reveal rapid

Todd, Robert E.

2011-01-01T23:59:59.000Z

182

Fish Detection in Underwater Video of Benthic Habitats in Virgin Islands.  

E-Print Network (OSTI)

??The research of underwater creatures is a fascinating work to marine biologists and environmental experts. However, finding and segmenting underwater creatures in underwater images and… (more)

Wu, Nan

2012-01-01T23:59:59.000Z

183

RELIABILITY CONSIDERATIONS OF ELECTRONICS COMPONENTS FOR THE DEEP UNDERWATER MUON AND NEUTRINO DETECTION SYSTEM  

E-Print Network (OSTI)

Considerations for the Dtep Underwater Muon and NeutrinoPresented at the Deep Underwater Huon and Neutrino DetectionCOMPONENTS FOR THE DEEP UNDERWATER MUON AND NEUTRINO

Leskovar, B.

2010-01-01T23:59:59.000Z

184

Underwater Mirror Exposure to Free-Ranging Naïve Atlantic Spotted Dolphins (Stenella frontalis) in the Bahamas  

E-Print Network (OSTI)

Vocalizations and associated underwater behavior of free-Comparative Psychology Underwater Mirror Exposure to Free-frontalis) has been studied underwater in the Bahamas. We

Delfour, Fabienne; Herzing, Denise

2013-01-01T23:59:59.000Z

185

PHOTOMULTIPLIER CHARACTERISTICS CONSIDERATIONS FOR THE DEEP UNDERWATER MUON AND NEUTRINO DETECTION SYSTEM  

E-Print Network (OSTI)

Presented at the Deep Underwater Huon and Neutrino DetectionCONSIDERATIONS FOR THE DEEP UNDERWATER HUON AND NEUTRINOPresented at the Deep Underwater Huon and Neutrino Detection

Leskovar, B.

2010-01-01T23:59:59.000Z

186

Special Issue "Underwater Sensor Nodes and Underwater Sensor Networks" A special issue of Sensors (ISSN 1424-8220)  

E-Print Network (OSTI)

Special Issue "Underwater Sensor Nodes and Underwater Sensor Networks" A special issue of Sensors (ISSN 1424-8220) Website: http://www.mdpi.com/journal/sensors/special_issues/underwater_sens Journal prediction, oil monitoring and so on. This special issue tries to collect the recent advances on underwater

Chen, Min

187

Recovery of underwater visibility and structure by polarization analysis  

E-Print Network (OSTI)

Abstract—Underwater imaging is important for scientific research and technology as well as for popular activities, yet it is plagued by poor visibility conditions. In this paper, we present a computer vision approach that removes degradation effects in underwater vision. We analyze the physical effects of visibility degradation. It is shown that the main degradation effects can be associated with partial polarization of light. Then, an algorithm is presented, which inverts the image formation process for recovering good visibility in images of scenes. The algorithm is based on a couple of images taken through a polarizer at different orientations. As a by-product, a distance map of the scene is also derived. In addition, this paper analyzes the noise sensitivity of the recovery. We successfully demonstrated our approach in experiments conducted in the sea. Great improvements of scene contrast and color correction were obtained, nearly doubling the

Yoav Y. Schechner; Nir Karpel

2005-01-01T23:59:59.000Z

188

Underwater radiation detector  

DOE Patents (OSTI)

A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

Kruse, Lyle W. (Albuquerque, NM); McKnight, Richard P. (Albuquerque, NM)

1986-01-01T23:59:59.000Z

189

Prompt muon contribution to the flux underwater  

E-Print Network (OSTI)

We present high energy spectra and zenith-angle distributions of the atmospheric muons computed for the depths of the locations of the underwater neutrino telescopes. We compare the calculations with the data obtained in the Baikal and the AMANDA muon experiments. The prompt muon contribution to the muon flux underwater due to recent perturbative QCD-based models of the charm production is expected to be observable at depths of the large underwater neutrino telescopes. This appears to be probable even at rather shallow depths (1-2 km), provided that the energy threshold for muon detection is raised above $\\sim 100$ TeV.

T. S. Sinegovskaya; S. I. Sinegovsky

2000-07-21T23:59:59.000Z

190

MECHANICS AND NONLINEAR CONTROL: MAKING UNDERWATER VEHICLES  

E-Print Network (OSTI)

MECHANICS AND NONLINEAR CONTROL: MAKING UNDERWATER VEHICLES RIDE AND GLIDE Naomi Ehrich Leonard \\Lambda \\Lambda Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 naomi@princeton.edu Abstract: Methods from geometric mechanics and dynamical systems theory make

Leonard, Naomi

191

Turbulence Measurement from an Autonomous Underwater Vehicle  

Science Conference Proceedings (OSTI)

Horizontal profiles of the microstructure of velocity and temperature were obtained with a large autonomous underwater vehicle (AUV) using two piezoelectric shear probes, an FP07 thermistor, and three orthogonal accelerometers mounted on a sting ...

Edward R. Levine; Rolf G. Lueck

1999-11-01T23:59:59.000Z

192

Vertical Water Velocities from Underwater Gliders  

Science Conference Proceedings (OSTI)

The underwater glider is set to become an important platform for oceanographers to gather data within oceans. Gliders are usually equipped with a conductivity–temperature–depth (CTD) sensor, but a wide range of other sensors have been fitted to ...

Lucas Merckelbach; David Smeed; Gwyn Griffiths

2010-03-01T23:59:59.000Z

193

Development of tether mooring type underwater robot  

Science Conference Proceedings (OSTI)

For the purpose of detecting CO2 leaks during ocean CO2 sequestration, there is a need for independent underwater robots that can make observations while maintaining their position over the seabed against the current for long periods ...

Ya-Wen Huang; Koji Ueda; Kazuhiro Itoh; Edwardo F. Fukushima; Shigeo Hirose

2009-10-01T23:59:59.000Z

194

Underwater Camera Calibration Using Wavelength Triangulation  

Science Conference Proceedings (OSTI)

In underwater imagery, the image formation process includes refractions that occur when light passes from water into the camera housing, typically through a flat glass port. We extend the existing work on physical refraction models by considering the ...

Timothy Yau, Minglun Gong, Yee-Hong Yang

2013-06-01T23:59:59.000Z

195

Predicting the navigation performance of underwater vehicles  

Science Conference Proceedings (OSTI)

In this paper we present a general framework for predicting the positioning uncertainty of underwater vehicles. We apply this framework to common examples from marine robotics: standalone long baseline (LBL) positioning and integrated LBL reference and ...

Brian Bingham

2009-10-01T23:59:59.000Z

196

Design considerations for engineering Autonomous Underwater Vehicles  

E-Print Network (OSTI)

Autonomous Underwater Vehicles (AUVs) have been established as a viable tool for Oceanographic Sciences. Being untethered and independent, AUVs fill the gap in Ocean Exploration left by the existing manned submersible and ...

Shah, Vikrant P. (Vikrant Pankaj)

2007-01-01T23:59:59.000Z

197

Contributions to automated realtime underwater navigation  

E-Print Network (OSTI)

This dissertation presents three separate-but related-contributions to the art of underwater navigation. These methods may be used in postprocessing with a human in the loop, but the overarching goal is to enhance vehicle ...

Stanway, Michael Jordan

2012-01-01T23:59:59.000Z

198

Krill: An exploration in underwater sensor networks  

E-Print Network (OSTI)

While sensor networks have now become very popular on land, the underwater environment still poses some difficult problems. Communication is one of the difficult challenges under water. There are two options:

I Vasilescu; K Kotay; D Rus; L Overs; P Sikka; M Dunbabin; P Chen; P Corke

2005-01-01T23:59:59.000Z

199

Cooperative localization for autonomous underwater vehicles  

E-Print Network (OSTI)

Self-localization of an underwater vehicle is particularly challenging due to the absence of Global Positioning System (GPS) reception or features at known positions that could otherwise have been used for position ...

Bahr, Alexander

2009-01-01T23:59:59.000Z

200

XAUV : modular high maneuverability autonomous underwater vehicle  

E-Print Network (OSTI)

The design and construction of a modular test bed autonomous underwater vehicle (AUV) is analyzed. Although a relatively common stacked-hull design is used, the state of the art is advanced through an aggressive power ...

Walker, Daniel G. (Daniel George)

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization  

DOE Green Energy (OSTI)

Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a smaller aperture, 96-element array and a 200-meter tall meteorological tower. Analysis of the data successfully demonstrated the ability to estimate the vertical velocity profile using coherence data from the pressure array. Also, dynamical systems analysis methods were successful in identifying and tracking a gust type event. In addition to the passive acoustic profiling method, this program also investigated a rapid response Doppler SODAR system, the optimization of wind turbine blades for enhanced power with reduced aeroacoustic noise production, and the implementation of a wireless health monitoring system for the wind turbine blades. Each of these other objectives was met successfully. The use of phase unwrapping applied to SODAR data was found to yield reasonable results for per-pulse measurements. A health monitoring system design analysis was able to demonstrate the ability to use a very small number of sensors to monitor blade health based on the blade's overall structural modes. Most notable was the development of a multi-objective optimization methodology that successfully yielded an aerodynamic blade design that produces greater power output with reduced aerodynamic loading noise. This optimization method could be significant for future design work.

Murray, Nathan E.

2012-03-12T23:59:59.000Z

202

Uncertainty-driven view planning for underwater inspection  

E-Print Network (OSTI)

We discuss the problem of inspecting an underwater structure, such as a submerged ship hull, with an autonomous underwater vehicle (AUV). In such scenarios, the goal is to construct an accurate 3D model of the structure ...

Hollinger, Geoffrey A.

203

Development of a low-cost underwater manipulator.  

E-Print Network (OSTI)

??This thesis describes the design, modeling, manufacture, and testing of a low cost, multiple degree-of-freedom underwater manipulator. Current underwater robotic arm technologies are often expensive… (more)

Cooney, Lauren Alise

2006-01-01T23:59:59.000Z

204

Dissolved organic matters impact on colour reconstruction in underwater images  

Science Conference Proceedings (OSTI)

The natural properties of water column usually affect underwater imagery by suppressing high-energy light. In application such as color correction of underwater images estimation of water column parameters is crucial. Diffuse attenuation coefficients ...

J. Åhlén; D. Sundgren; T. Lindell; E. Bengtsson

2005-06-01T23:59:59.000Z

205

Underwater ultra-wideband fingerprinting-based localization.  

E-Print Network (OSTI)

??In this work a new location fingerprinting-based localization algorithm is proposed for an underwater medium by utilizing ultra-wideband (UWB) signals. In many conventional underwater systems,… (more)

Shakeri, S.

2012-01-01T23:59:59.000Z

206

Development of a low-cost underwater manipulator  

E-Print Network (OSTI)

This thesis describes the design, modeling, manufacture, and testing of a low cost, multiple degree-of-freedom underwater manipulator. Current underwater robotic arm technologies are often expensive or limited in functionality. ...

Cooney, Lauren Alise

2006-01-01T23:59:59.000Z

207

Design of small, low-cost, underwater fin manipulator  

E-Print Network (OSTI)

This thesis details the development of a small, low cost, underwater manipulator for use on the XAUV. At this time, there are no cheap underwater servos commercially available. The design involves modifying a commercially ...

Roberts, Megan Johnson

2008-01-01T23:59:59.000Z

208

The challenges of building scalable mobile underwater wireless sensor networks for aquatic applications  

E-Print Network (OSTI)

The large-scale mobile Underwater Wireless Sensor Network (UWSN) is a novel networking paradigm to explore aqueous environments. However, the characteristics of mobile UWSNs, such as low communication bandwidth, large propagation delay, floating node mobility, and high error probability, are significantly different from ground-based wireless sensor networks. The novel networking paradigm poses interdisciplinary challenges that will require new technological solutions. In particular, in this article we adopt a top-down approach to explore the research challenges in mobile UWSN design. Along the layered protocol stack, we proceed roughly from the top application layer to the bottom physical layer. At each layer, a set of new design intricacies are studied. The conclusion is that building scalable mobile UWSNs is a challenge that must be answered by interdisciplinary efforts of acoustic communications, signal processing, and mobile acoustic network protocol design. T

Jun-hong Cui; Jiejun Kong; Mario Gerla

2006-01-01T23:59:59.000Z

209

Underwater Human-Robot Interaction via Biological Motion Identification  

E-Print Network (OSTI)

Underwater Human-Robot Interaction via Biological Motion Identification Junaed Sattar and Gregory: {junaed, dudek}@cim.mcgill.ca Abstract-- We present an algorithm for underwater robots to visually detect pertaining to biological motion. This technique is applied to track scuba divers in underwater domains

Dudek, Gregory

210

An Underwater Robotic Network for Monitoring Nuclear Waste Storage Pools  

E-Print Network (OSTI)

An Underwater Robotic Network for Monitoring Nuclear Waste Storage Pools Sarfraz Nawaz1 , Muzammil must be stored for around 60 years in underwater storage pools before permanent disposal. These underwater storage environments must be carefully monitored and controlled to avoid an environmental

Jeavons, Peter

211

An Underwater Sensor Network with Dual Communications, Sensing, and  

E-Print Network (OSTI)

An Underwater Sensor Network with Dual Communications, Sensing, and Mobility Carrick Detweiller an underwater sensor network with dual communication and sup- port for sensing and mobility. The nodes developed. We describe the hardware details of the underwater sensor node and the communication

Farritor, Shane

212

Coastal Underwater Field Observer with Remote IP Access  

E-Print Network (OSTI)

Coastal Underwater Field Observer with Remote IP Access Joe Wilinski, Aaron Ganick, Alexander with continuous use of batteries. Costal Underwater Field Observer 9/16/09 #12;Boston University Slideshow Title? Wide angle Zoom Costal Underwater Field Observer #12;Boston University Slideshow Title Goes Here

Goldberg, Bennett

213

Batoid Fishes: Inspiration for the Next Generation of Underwater Robots  

E-Print Network (OSTI)

P A P E R Batoid Fishes: Inspiration for the Next Generation of Underwater Robots A U T H O R-endurance swimming that can outperform current underwater vehicle technology in the areas of stealth, maneuverability batoid fishes an ideal platform to emulate in the design of a bio-inspired autonomous underwater vehicle

Fish, Frank

214

Integrated Short Term Navigation of a Towed Underwater Body*  

E-Print Network (OSTI)

Integrated Short Term Navigation of a Towed Underwater Body* G. Damy' M. Joannides2 F. LeGland3 M. An underwater body, to be called here- after the fish, is towed by a surface ship at the end of a few hundred cannot provide any position estimates of an underwater body such as a towed fish, but only position

LeGland, François

215

LFT/H varying sampling control for Autonomous Underwater Vehicles  

E-Print Network (OSTI)

LFT/H varying sampling control for Autonomous Underwater Vehicles E. Roche , O. Sename D. Simon: This paper deals with the robust control of an Autonomous Underwater Vehicle (AUV) subject to communication. INTRODUCTION In this paper the H approach for LPV systems is applied to an Autonomous Underwater Vehicle (AUV

Paris-Sud XI, Université de

216

Underwater vehicles: The minimum time problem Department of Mathematics  

E-Print Network (OSTI)

Underwater vehicles: The minimum time problem M. Chyba Department of Mathematics 2565 McCarthy Mall for a class of underwater vehicles. We focus on the situation of initial and final configurations at rest In this paper we pursue the analysis of the minimum time problem for a special class of underwater vehicles, see

Sontag, Eduardo

217

A camcorder for 3D underwater reconstruction of archeological objects  

E-Print Network (OSTI)

A camcorder for 3D underwater reconstruction of archeological objects A. Meline1 , J. Triboulet1 Cedex 5, France 2 Université de Nîmes, Place Gabriele Péri, 30021 Nîmes, France Abstract- The underwater cartography has made great progress in the last decade. In this paper, we discuss of the 3D underwater

Paris-Sud XI, Université de

218

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES  

E-Print Network (OSTI)

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH AND HENRIK KALISCH Abstract. Consideration is given to the influence of an underwater landslide on waves at the surface distinct generation mechanisms of a tsunami are underwater earth- quakes, and submarine mass failures

219

ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND  

E-Print Network (OSTI)

ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND Marine Biological Laboratory NOV 9 -1953 WOODS, Director ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND by Clifford J. Burner and Harvey Lo Moore" - Electro-magnetic transducer 6 Piezo-electric crystal transducer l8 "Wampus" - Underwater turbine 20

220

UNDERWATER TELEVISION VEHICLE FOR USE IN FISHERIES RESEARCH  

E-Print Network (OSTI)

UNDERWATER TELEVISION VEHICLE FOR USE IN FISHERIES RESEARCH (Marine Biological Laboratoiy j -. :I57 UNDERWATER TELEVISION VEHiaE FOR USE IN FISHERIES RESEARCH By R. F. Sand/""and R. L. McNeely''"* K^hief, Gear IN UMDERSFA RESEARCH 12 REFERENCES l5 LIST OF ILLUSTRATIONS Figure 1. Underwater Television Vehicle 3 2

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Mote-based Underwater Sensor Networks: Opportunities, Challenges, and Guidelines  

E-Print Network (OSTI)

Mote-based Underwater Sensor Networks: Opportunities, Challenges, and Guidelines Raja Jurdak (lopes@uci.edu) University of California, Irvine CA 92697 USA Abstract. Most underwater networks rely deployments of underwater sensor networks and has forced researchers to use simulations to investigate

Lopes, Cristina Videira

222

ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND  

E-Print Network (OSTI)

403 ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND -iD^ SPECIAL SCIENTIFK REPOKT-FISHERIES Na ATTEMPTS TO GUIDE SMALL FISH WITH UNDERWATER SOUND by Clifford J. Burner and Harvey L.. Moore United States-electric crystal transducer "Wampus" - Underwater turbine Electromagnetic transducer. Bell (lK-2) Summary

223

Underwater locomotion from oscillatory shape deformations Patricio A. Vela  

E-Print Network (OSTI)

Underwater locomotion from oscillatory shape deformations Patricio A. Vela , Kristi A. Morgansen@robotics.caltech.edu Abstract: This paper considers underwater propulsion that is generated by variations in body shape. We underwater vehicles that propel and steer themselves by changes in shape (e.g. [11, 13, 15

Sontag, Eduardo

224

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES  

E-Print Network (OSTI)

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH # AND HENRIK KALISCH Abstract. Consideration is given to the influence of an underwater landslide on waves at the surface of a tsunami are underwater earth­ quakes, and submarine mass failures. Among the broad class of submarine mass

225

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES  

E-Print Network (OSTI)

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH AND HENRIK KALISCH Abstract. Consideration is given to the influence of an underwater landslide on waves at the surface tsunamis. Two distinct generation mechanisms of a tsunami are underwater earthquakes, and submarine mass

226

Underwater Color Constancy : Enhancement of Automatic Live Fish Recognition  

E-Print Network (OSTI)

Underwater Color Constancy : Enhancement of Automatic Live Fish Recognition M. Chambah, D. Semani-mail: rizzi@dti.unimi.it ABSTRACT We present in this paper some advances in color restoration of underwater images, especially with regard to the strong and non uniform color cast which is typical of underwater

Paris-Sud XI, Université de

227

Underwater vehicles: The minimum time problem Department of Mathematics  

E-Print Network (OSTI)

Underwater vehicles: The minimum time problem M. Chyba Department of Mathematics 2565 McCarthy Mall for a class of underwater vehicles. We focus on the situation of initial and final configurations at rest the analysis of the minimum time problem for a special class of underwater vehicles, see [5], [6] for previous

Sussmann, Hector

228

An algebraic perspective to single-transponder underwater navigation  

E-Print Network (OSTI)

An algebraic perspective to single-transponder underwater navigation J´er^ome Jouffroy and Johann Reger Abstract-- This paper studies the position estimation of an underwater vehicle using a single are presented to illus- trate the approach. I. INTRODUCTION As an underwater counterpart of GPS, Long Base

Knobloch,Jürgen

229

Clean, economical, underwater (hydrocarbon) storage  

SciTech Connect

A consortium consisting of Howaldtswerke-Deutsche Werft A.G., Phoenix Gummiwerke A.G., Strabag Bau-A.G., and Bugsier Reederei und Bergungs-A.G. offers a plausible solution to the large-scale underwater storage of hydrocarbons. Up to 20 storage compartments of 8000 cu m capacity can be assembled for a capacity of 160,000 cu m. Each compartment is divided in half by a nylon-reinforced polyurethane diaphragm which isolates oil or other products on one side from sea-water ballast on the other side. As oil is pumped into storage on one side of the diaphragm, the diaphragm moves and ballast on the other side is displaced to the sea. Ballast re-enters the compartment during unloading. The system can enable small offshore platforms to produce more economically. Cargo tankers load at 8000 cu m/hr. The tanks will be used in 200 m or greater water depths. The loading station is installed in a buoy 30 m below the water surface.

1978-08-01T23:59:59.000Z

230

WILEY WCMC SPECIAL ISSUE ON UNDERWATER SENSOR NETWORKS (INVITED) 1 Prospects and Problems of Wireless Communication for Underwater  

E-Print Network (OSTI)

WILEY WCMC SPECIAL ISSUE ON UNDERWATER SENSOR NETWORKS (INVITED) 1 Prospects and Problems of Wireless Communication for Underwater Sensor Networkss Lanbo Liu, Shengli Zhou, and Jun-Hong Cui The work ISSUE ON UNDERWATER SENSOR NETWORKS (INVITED) 2 Abstract This paper reviews the physical fundamentals

Cui, Jun-Hong

231

Copyright Journal of Ocean Technology 2009 Underwater Intervention, Vol. 4, No. 1, 2009 7 Autonomous Underwater Gliders (AUGs) are  

E-Print Network (OSTI)

Copyright Journal of Ocean Technology 2009 Underwater Intervention, Vol. 4, No. 1, 2009 7 Autonomous Underwater Gliders (AUGs) are becoming the tool of choice for oceanographers to collect in of Ocean Gliders A glider is a type of autonomous underwater vehicle (AUV) that is able to move for weeks

deYoung, Brad

232

DUMAND-II (deep underwater muon and neutrino detector) progress report  

SciTech Connect

The DUMAND II detector will search for astronomical sources of high energy neutrinos. Successful deployment of the basic infrastructure, including the shore cable, the underwater junction box, and an environmental module was accomplished in December, 1993. One optical module string was also deployed and operated, logging data for about 10 hours. The underwater cable was connected to the shore station where we were able to successfully exercise system controls and log further environmental data. After this time, water leaking into the electronics control module for the deployed string disabled the string electrical system. The acquired data are consistent with the expected rate of downgoing muons, and our ability to reconstruct muons was demonstrated. The measured acoustical backgrounds are consistent with expectation, which should allow acoustical detection of nearby PeV particle cascades. The disabled string has been recovered and is undergoing repairs ashore. We have identified the source of the water leak and implemented additional testing and QC procedures to ensure no repetition in our next deployment. We will be ready to deploy three strings and begin continuous data taking in late 1994 or early 1995. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Young, K.K. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); The DUMAND Collaboration

1995-07-10T23:59:59.000Z

233

DUMAND-II (Deep Underwater Muon and Neutrino Detector) PROGRESS Report  

E-Print Network (OSTI)

The DUMAND-II detector will search for astronomical sources of high energy neutrinos. Successful deployment of the basic infrastructure, including the shore cable, the underwater junction box, and an environmental module was accomplished in December, 1993. One optical module string was also deployed and operated, logging data for about 10 hours. The underwater cable was connected to the shore station where we were able to successfully exercise system controls and log further environmental data. After this time, water leaking into the electronics control module for the deployed string disabled the string electrical system. The acquired data are consistent with the expected rate of downgoing muons, and our ability to reconstruct muons was demonstrated. The measured acoustical backgrounds are consistent with expectation, which should allow acoustical detection of nearby PeV particle cascades. The disabled string has been recovered and is undergoing repairs ashore. We have identified the source of the water leak and implemented additional testing and QC procedures to ensure no repetition in our next deployment. We will be ready to deploy three strings and begin continuous data taking in 1995.

Kenneth K. Young

1994-12-16T23:59:59.000Z

234

Remotely operated submersible underwater suction apparatus  

DOE Patents (OSTI)

A completely submersible, remotely operated underwater suction device for collection of irradiated materials in a nuclear pool is disclosed. The device includes a pump means for pumping water through the device, a filter means for capturing irradiated debris, remotely operated releasable connector means, a collection means and a means for remotely maneuvering the collection means. The components of the suction device may be changed and replaced underwater to take advantage of the excellent radiation shielding ability of water to thereby minimize exposure of personnel to radiation.

Kristan, Louis L. (2111 Brentwood Dr., Idaho Falls, ID 83402)

1990-01-01T23:59:59.000Z

235

Applications of Underwater Search and Identification Technology on Monitoring of Underwater Structures and Analysis of Upper-Layer Geological Properties of Seabed.  

E-Print Network (OSTI)

??The application of underwater search and identification technology has been widely used in the underwater engineering. There are two major fields in this thesis: monitoring… (more)

Yeh, Ti-ting

2005-01-01T23:59:59.000Z

236

Development of Underwater Laser Cladding and Underwater Laser Seal Welding Techniques for Reactor Components (II)  

SciTech Connect

Stress corrosion cracking (SCC) is one of the major reasons to reduce the reliability of aged reactor components. Toshiba has been developing underwater laser welding onto surface of the aged components as maintenance and repair techniques. Because most of the reactor internal components to apply this underwater laser welding technique have 3-dimensional shape, effect of welding positions and welded shapes are examined and presented in this report. (authors)

Masataka Tamura; Shohei Kawano; Wataru Kouno; Yasushi Kanazawa [Toshiba Corporation (Japan)

2006-07-01T23:59:59.000Z

237

On the Order Optimality of Large-scale Underwater Networks  

E-Print Network (OSTI)

Capacity scaling laws are analyzed in an underwater acoustic network with $n$ regularly located nodes on a square, in which both bandwidth and received signal power can be limited significantly. A narrow-band model is assumed where the carrier frequency is allowed to scale as a function of $n$. In the network, we characterize an attenuation parameter that depends on the frequency scaling as well as the transmission distance. Cut-set upper bounds on the throughput scaling are then derived in both extended and dense networks having unit node density and unit area, respectively. It is first analyzed that under extended networks, the upper bound is inversely proportional to the attenuation parameter, thus resulting in a highly power-limited network. Interestingly, it is seen that the upper bound for extended networks is intrinsically related to the attenuation parameter but not the spreading factor. On the other hand, in dense networks, we show that there exists either a bandwidth or power limitation, or both, ac...

Shin, Won-Yong; Medard, Muriel; Stojanovic, Milica; Tarokh, Vahid

2011-01-01T23:59:59.000Z

238

KE Basin underwater visual fuel survey  

SciTech Connect

Results of an underwater video fuel survey in KE Basin using a high resolution camera system are presented. Quantitative and qualitative information on fuel degradation are given, and estimates of the total fraction of ruptured fuel elements are provided. Representative photographic illustrations showing the range of fuel conditions observed in the survey are included.

Pitner, A.L.

1995-02-01T23:59:59.000Z

239

Acoustic transducer  

DOE Patents (OSTI)

An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

Drumheller, D.S.

1997-12-30T23:59:59.000Z

240

Acoustic transducer  

DOE Patents (OSTI)

An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

Drumheller, Douglas S. (Cedar Crest, NM)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Neutron Interrogation System For Underwater Threat Detection And Identification  

Science Conference Proceedings (OSTI)

Wartime and terrorist activities, training and munitions testing, dumping and accidents have generated significant munitions contamination in the coastal and inland waters in the United States and abroad. Although current methods provide information about the existence of the anomaly (for instance, metal objects) in the sea bottom, they fail to identify the nature of the found objects. Field experience indicates that often in excess of 90% of objects excavated during the course of munitions clean up are found to be non-hazardous items (false alarm). The technology to detect and identify waterborne or underwater threats is also vital for protection of critical infrastructures (ports, dams, locks, refineries, and LNG/LPG). We are proposing a compact neutron interrogation system, which will be used to confirm possible threats by determining the chemical composition of the suspicious underwater object. The system consists of an electronic d-T 14-MeV neutron generator, a gamma detector to detect the gamma signal from the irradiated object and a data acquisition system. The detected signal then is analyzed to quantify the chemical elements of interest and to identify explosives or chemical warfare agents.

Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C. [Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd, 11077 Bowling Green, KY 42101 (United States)

2009-03-10T23:59:59.000Z

242

Optical Delineation of Benthic Habitat Using an Autonomous Underwater Vehicle  

SciTech Connect

To improve understanding and characterization of coastal regions, there has been an increasing emphasis on autonomous systems that can sample the ocean on relevant scales. Autonomous underwater vehicles (AUVs) with active propulsion are especially well suited for studies of the coastal ocean because they are able to provide systematic and near-synoptic spatial observations. With this capability, science users are beginning to integrate sensor suits for a broad range of specific and often novel applications. Here, the relatively mature Remote Environmental Monitoring Units (REMUS) AUV system is configured with multi-spectral radiometers to delineate benthic habitat in Sequim Bay, WA. The vehicle was deployed in a grid pattern along 5 km of coastline in depths from 30 to less than 2 meters. Similar to satellite and/or aerial remote sensing, the bandwidth ratios from the downward looking radiance sensor and upward looking irradiance sensor were used to identify beds of eelgrass on sub-meter scales. Strong correlations were found between the optical reflectance signals and the geo-referenced in situ data collected with underwater video within the grid. Results demonstrate the ability of AUVs to map littoral habitats at high resolution and highlight the overall utility of the REMUS vehicle for nearshore oceanography.

Moline, Mark A.; Woodruff, Dana L.; Evans, Nathan R.

2007-06-01T23:59:59.000Z

243

Virtual long baseline (VLBL) autonomous underwater vehicle navigation using a single transponder  

E-Print Network (OSTI)

(cont.) Therefore, accurate underwater navigation using a single location transponder would provide dramatic time and cost savings for underwater vehicle operations. This thesis presents a simulation of autonomous underwater ...

LaPointe, Cara Elizabeth Grupe

2006-01-01T23:59:59.000Z

244

Acoustic cryocooler  

DOE Patents (OSTI)

An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintain a cooling load of 5 W at 80 K. 3 figs.

Swift, G.W.; Martin, R.A.; Radebaugh, R.

1989-09-26T23:59:59.000Z

245

Acoustic cryocooler  

DOE Patents (OSTI)

An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

Swift, Gregory W. (Santa Fe, NM); Martin, Richard A. (Los Alamos, NM); Radenbaugh, Ray (Louisville, CO)

1990-01-01T23:59:59.000Z

246

Acoustic telemetry.  

Science Conference Proceedings (OSTI)

Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

2003-08-01T23:59:59.000Z

247

Reconstruction of 3D Points From Uncalibrated Underwater Video.  

E-Print Network (OSTI)

??This thesis presents a 3D reconstruction software pipeline that is capable of generating point cloud data from uncalibrated underwater video. This research project was undertaken… (more)

Cavan, Neil

2011-01-01T23:59:59.000Z

248

Modelling and control of underwater inspection vehicle for aquaculture sites.  

E-Print Network (OSTI)

?? Underwater vehicles such as AUVs and ROVs with hovering capabilities is a promising method for inspection of net integrity in large scale, sea based,… (more)

Hval, Mats Nåvik

2012-01-01T23:59:59.000Z

249

Underwater kicking following the freestyle tumble-turn.  

E-Print Network (OSTI)

??Swim turns are a component of competitive swimming where considerable advantage can be gained or lost. This thesis investigates underwater dolphin and flutter kicking techniques… (more)

Clothier, Peter

2004-01-01T23:59:59.000Z

250

High-Speed Fracture Phenomena of Glass Bottle by Underwater ...  

Science Conference Proceedings (OSTI)

Presentation Title, High-Speed Fracture Phenomena of Glass Bottle by Underwater Shock Wave. Author(s), Hidetoshi Sakamoto, Shinjirou Kawabe, Yoshifumi ...

251

Development of a Field Deployable Underwater Laser Scanning System.  

E-Print Network (OSTI)

??As humans seek to explore and exploit underwater environments and resources the need for tools and techniques to assist in this is critical. An important… (more)

Gillham, Jason

2011-01-01T23:59:59.000Z

252

Underwater tanker ballast water/oil separation  

SciTech Connect

The invention contemplates tranferring ballast water contaminated with entrained or emulsified oil to an underwater disengagement zone operating on the water displacement principle, as exemplified by an underwater storage tank having an upwardly convex shell with an opening in its bottom through which water can move into and out of the shell as the volume of oil enclosed within the storage zone fluctuates. The ballast mixture of water and oil is introduced into the disengagement zone, where it separates under the influence of gravity into separate oil and water phases. The oil layer rises to a point from which it can be recovered, while the separated water flows out of the open bottom of the zone into the body of water. (2 claims)

McCabe, J.S.

1973-10-02T23:59:59.000Z

253

Underwater splice for submarine coaxial cable  

SciTech Connect

The invention is a device for splicing submarine coaxial cable underwater on the seafloor with a simple push-on operation to restore and maintain electrical and mechanical strength integrity; the splice device is mateable directly with the severed ends of a coaxial cable to be repaired. Splicing assemblies comprise a dielectric pressure compensating fluid filled guide cavity, a gelled castor oil cap and wiping seals for exclusion of seawater, electrical contacts, a cable strength restoration mechanism, and a pressure compensation system for controlled extrusion of and depletion loss prevention of dielectric seal fluid during cable splicing. A splice is made underwater by directly inserting prepared ends of coaxial cable, having no connector attachments, into splicing assemblies.

Inouye, A.T.; Roe, T. Jr.; Tausing, W.R.; Wilson, J.V.

1984-10-30T23:59:59.000Z

254

Review of potential impacts to sea turtles from underwater explosive removal of offshore structures  

SciTech Connect

The purpose of this study was to collect and synthesize existing information relevant to the explosive removal of offshore structures (EROS) in aquatic environments. Data sources were organized and summarized by topic - explosive removal methods, physics of underwater explosions, sea turtle resources, documented impacts to sea turtles, and mitigation of effects. Information was gathered via electronic database searches and literature source review. Bulk explosive charges are the most commonly used technique in EROS. While the physical principles of underwater detonations and the propagation of pressure and acoustic waves are well understood, there are significant gaps in the application of this knowledge. Impacts to sea turtles from explosive removal operations may range from non-injurious effects (e.g. acoustic annoyance; mild tactile detection or physical discomfort) to varying levels of injury (i.e. non-lethal and lethal injuries). Very little information exists regarding the impacts of underwater explosions on sea turtles. Effects of explosions on turtles often must be inferred from documented effects to other vertebrates with lungs or other gas-containing organs, such as mammals and most fishes. However, a cautious approach should be used when determining impacts to sea turtles based on extrapolations from other vertebrates. The discovery of beached sea turtles and bottlenose dolphins following an explosive platform removal event in 1986 prompted the initiation of formal consultation between the U.S. Department of the Interior, Minerals Management Service (MMS) and the National Marine Fisheries Service (NMFS), authorized through the Endangered Species Act Section 7, to determine a mechanism to minimize potential impacts to listed species. The initial consultation resulted in a requirement for oil and gas companies to obtain a permit (through separate consultations on a case-by-case basis) prior to using explosives in Federal waters. Because many offshore structure removal operations are similar, a 'generic' Incidental Take Statement was established by the NMFS that describes requirements to protect sea turtles when an operator's individual charge weights did not exceed 50 lb (23 kg). Requirements associated with the Incidental Take Permit were revised in 2003 and 2006 to accommodate advances in explosive charge technologies, removals of structures in deeper waters, and adequate protection of deep water marine mammal species in Gulf of Mexico waters. Generally, these requirements include pre- and post-detonation visual monitoring using standard surface and aerial survey methods for sea turtles and marine mammals, and, in some scenarios, passive acoustic survey methods for marine mammals within a specified radius from an offshore structure. The survey program has been successful in mitigating impacts to sea turtles associated with EROS. However, even with these protective measures in place, there have been observations of sea turtles affected by explosive platform removals.

Viada, Stephen T. [CSA International, Inc., 759 Parkway Street, Jupiter, FL 33477 (United States)], E-mail: sviada@conshelf.com; Hammer, Richard M. [CSA International, Inc., 759 Parkway Street, Jupiter, FL 33477 (United States)], E-mail: rhammer@conshelf.com; Racca, Roberto [JASCO Research Ltd., Vancouver Island Technology Park, Suite 2101, 4464 Markham Street, Victoria, British Columbia, V8Z 7X8 (Canada)], E-mail: rob@jasco.com; Hannay, David [JASCO Research Ltd., Vancouver Island Technology Park, Suite 2101, 4464 Markham Street, Victoria, British Columbia, V8Z 7X8 (Canada)], E-mail: dave@jasco.com; Thompson, M. John [CSA International, Inc., 759 Parkway Street, Jupiter, FL 33477 (United States)], E-mail: jthompson@conshelf.com; Balcom, Brian J. [CSA International, Inc., 759 Parkway Street, Jupiter, FL 33477 (United States)], E-mail: bbalcom@conshelf.com; Phillips, Neal W. [CSA International, Inc., 759 Parkway Street, Jupiter, FL 33477 (United States)], E-mail: nphillips@conshelf.com

2008-05-15T23:59:59.000Z

255

Acoustic Logs | Open Energy Information  

Open Energy Info (EERE)

Acoustic Logs Acoustic Logs Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Acoustic Logs Details Activities (7) Areas (6) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: determine porosity of layers Stratigraphic/Structural: map discontinuities to determine their orientation. Hydrological: Thermal: Cost Information Low-End Estimate (USD): 1.00100 centUSD 1.0e-3 kUSD 1.0e-6 MUSD 1.0e-9 TUSD / foot Median Estimate (USD): 4.62462 centUSD 0.00462 kUSD 4.62e-6 MUSD 4.62e-9 TUSD / foot High-End Estimate (USD): 16.001,600 centUSD 0.016 kUSD 1.6e-5 MUSD 1.6e-8 TUSD / foot

256

A Framework for Testing of Wireless Underwater Robots  

Science Conference Proceedings (OSTI)

Underwater applications of wireless robots are foreseen to hold a market potential. The standardization process will drive the development of the necessary technology so that devices can work cooperatively. Specific testing procedures have to be developed ... Keywords: Conformance, Interoperability, Testing, Underwater, Wireless robot

J. Poncela; M. C. Aguayo-Torres

2013-06-01T23:59:59.000Z

257

Application of optimization algorithms to trajectory planning for underwater gliders  

Science Conference Proceedings (OSTI)

Underwater gliders are a technology that have demonstrated to be a valid tool for diverse applications in the oceans including validation of currents models, environmental control or security. Due to their low speed, gliders might drift significantly ... Keywords: path planning, underwater gliders

José Isern-Gonz$#225;lez; Daniel Hern$#225;ndez-Sosa; Enrique Fern$#225;ndez-Perdomo; Jorge Cabrera-G$#225;mez; Antonio C. Domínguez-Brito; Víctor Prieto-Marañón

2011-02-01T23:59:59.000Z

258

Study on Hydrodynamic Outline of an Unmanned Underwater Vehicle  

Science Conference Proceedings (OSTI)

Unmanned Underwater Vehicle (UUV) is being widely developed and used in many areas. In order to meet the low resistance and low noise requirements of a kind of UUV for long voyage, the outline curve and parameters of different sections of the UUV are ... Keywords: Unmanned underwater vehicle, Hydrodynamic outline, Low resistance, Low noise

Shao Zhiyu, Fang Jing, Feng Shunshan, Cheng Yufeng

2013-01-01T23:59:59.000Z

259

Sensor-based Behavior Control for an Autonomous Underwater Vehicle  

Science Conference Proceedings (OSTI)

In this paper, we evaluate a set of core functions that allow an underwater robot to perform surveillance under operator control. Specifically, we are interested in behaviors that facilitate the monitoring of organisms on a coral reef, and we present ... Keywords: Underwater robotics, adaptive gait control, computer vision, swimming robots, symbolic languages, visual human-robot interaction, visual servoing

Junaed Sattar; Philippe Giguère; Gregory Dudek

2009-06-01T23:59:59.000Z

260

Underwater vehicle localization using range measurements  

E-Print Network (OSTI)

This thesis investigates the problem of cooperative navigation of autonomous marine vehicles using range-only acoustic measurements. We consider the use of a single maneuvering autonomous surface vehicle (ASV) to aid the ...

Papadopoulos, Ge?rgios

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Design and implementation of an underwater sound recording device  

SciTech Connect

The purpose of this study was to design and build two versions of an underwater sound recording device. The device designed is referred to as the Underwater Sound Recorder (USR), which can be connected to one or two hydrophones or other underwater sound sensors. The URS contains a 26 dB preamplifier and a user selectable gain that permits additional amplification of input to the system from 26 dB to 46 dB. Signals within the frequency range up to 15 kHz may be recorded using the USR. Examples of USR applications are monitoring underwater processes that have the potential to create large pressure waves that could potentially harm fish or other aquatic life, such as underwater explosions or pile driving. Additional applications are recording sound generated by vessels or the vocalizations of some marine mammals, such as the calls from many species of whales.

Martinez, Jayson J.; Myers, Joshua R.; Carlson, Thomas J.; Deng, Zhiqun; Rohrer, John S.; Caviggia, Kurt A.

2011-09-19T23:59:59.000Z

262

Analysis of using fuel cell technology for autonomous underwater vehicle power supply  

Science Conference Proceedings (OSTI)

Nowadays underwater robotics aims at semi or whole autonomous underwater vehicles. Autonomy of underwater robots depends on their control systems usually based on artificial intelligence methods and capacity of supply sources mounted on their boards. ... Keywords: fuel cell, underwater vehicle power supply

Grzegorz Grzeczka; Piotr Szymak

2009-05-01T23:59:59.000Z

263

Proceedings of the 2008 IFAC Workshop on Navigation, Guidance and Control of Underwater Vehicles  

E-Print Network (OSTI)

Proceedings of the 2008 IFAC Workshop on Navigation, Guidance and Control of Underwater Vehicles Autonomous Underwater Multivehicle Control with Limited Communication: Theory and Experiment Daniel J. Klein underwater vehicles linked via underwater communi- cation. By treating heading angle as oscillator phase

Morgansen, Kristi

264

Underwater robots require adequate guidance and control to perform useful tasks. Visual  

E-Print Network (OSTI)

Abstract Underwater robots require adequate guidance and control to perform useful tasks. Visual trained by reinforcement learn- ing our aim is to enable an underwater robot to hold station on a reef technologies for underwater exploration and obser- vation. Our objectives are to enable underwater robots

265

Aqua-Net: An Underwater Sensor Network Architecture --Design and Implementation  

E-Print Network (OSTI)

Aqua-Net: An Underwater Sensor Network Architecture -- Design and Implementation Zheng Peng, Zhong Department, University of Connecticut, Storrs, CT 06269 Abstract Underwater sensor network (UWSN) has emerged architecture for underwater sensor network. This paper proposes AQUA-NET, an architecture for underwater sensor

Cui, Jun-Hong

266

HIPPOPOTAMUS UNDERWATER LOCOMOTION: REDUCED-GRAVITY MOVEMENTS FOR A MASSIVE MAMMAL  

E-Print Network (OSTI)

HIPPOPOTAMUS UNDERWATER LOCOMOTION: REDUCED- GRAVITY MOVEMENTS FOR A MASSIVE MAMMAL BRITTANY L on land by such heavy animals. Videos of the underwater locomotion of 2 hippopotami were analyzed frame by frame. Average horizontal velocity underwater was 0.47 m/s. Hippopotami used a gait underwater

Fish, Frank

267

Specs add confidence in use of wet welding. [Underwater welding  

SciTech Connect

Underwater wet welding can now be utilized with the same confidence as dry welding, provided certain guidelines are followed. A new electrode is discussed that has been delivering exceptionally high quality welds by a diving firm in Houston. With the issuance of the American Welding Society's specifications (ANS/LAWS D3.6-83) much of the confusion surrounding underwater welding should be eliminated. The new specifications establish the levels of quality for underwater welding and gives everyone in the business a common language.

1984-02-01T23:59:59.000Z

268

Algorithms and analysis for underwater vehicle plume tracing.  

SciTech Connect

The goal of this research was to develop and demonstrate cooperative 3-D plume tracing algorithms for miniature autonomous underwater vehicles. Applications for this technology include Lost Asset and Survivor Location Systems (L-SALS) and Ship-in-Port Patrol and Protection (SP3). This research was a joint effort that included Nekton Research, LLC, Sandia National Laboratories, and Texas A&M University. Nekton Research developed the miniature autonomous underwater vehicles while Sandia and Texas A&M developed the 3-D plume tracing algorithms. This report describes the plume tracing algorithm and presents test results from successful underwater testing with pseudo-plume sources.

Byrne, Raymond Harry; Savage, Elizabeth L. (Texas A& M University, College Station, TX); Hurtado, John Edward (Texas A& M University, College Station, TX); Eskridge, Steven E.

2003-07-01T23:59:59.000Z

269

Cross-Dipole Acoustic Log | Open Energy Information  

Open Energy Info (EERE)

Cross-Dipole Acoustic Log Cross-Dipole Acoustic Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Cross-Dipole Acoustic Log Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Acoustic Logs Information Provided by Technique Lithology: Stratigraphic/Structural: Rock stress and fracture analysis Hydrological: Use for fracture identification in open and cased holes. Also used for evaluating hydro fracturing/well stimulation effectiveness. Thermal: Dictionary.png Cross-Dipole Acoustic Log: An acoustic logging technique where the acoustic transmitter and receivers are lowered down hole and waveforms that travel through the well mud,

270

Sensor Data Processing for Tracking Underwater Threats Using Terascale Optical Core Devices  

SciTech Connect

A critical aspect of littoral surveillance (including port protection) involves the localization and tracking of underwater threats such as manned or unmanned autonomous underwater vehicles. In this article, we present a methodology for locating underwater threat sources from uncertain sensor network data, and illustrate the threat tracking aspects using active sonars in a matched filter framework. The novelty of the latter paradigm lies in its implementation on a tera-scale optical core processor, EnLight , recently introduced by Lenslet Laboratories. This processor is optimized for array operations, which it performs in a fixed point arithmetic architecture at tera-scale throughput. Using the EnLight 64 prototype processor, our results (i) illustrate the ability to reach a robust tracking accuracy, and (ii) demonstrate that a considerable speed-up (a factor of over 13,000) can be achieved when compared to an Intel XeonTM processor in the computation of sets of 80K-sample complex Fourier transforms that are associated with our matched filter techniques.

Barhen, Jacob [ORNL; Imam, Neena [ORNL

2009-01-01T23:59:59.000Z

271

Modeling and control of a biorobotic autonomous underwater vehicle  

E-Print Network (OSTI)

Current research into Autonomous Underwater Vehicles (AUVs) has included work on biologically inspired propulsion mechanisms, for instance flapping foils. The first aim of this thesis is to develop an accurate non-linear ...

Booth, William Duncan Lewis

2006-01-01T23:59:59.000Z

272

Autonomous underwater vehicle navigation and mapping in dynamic, unstructured environments  

E-Print Network (OSTI)

This thesis presents a system for automatically building 3-D optical and bathymetric maps of underwater terrain using autonomous robots. The maps that are built improve the state of the art in resolution by an order of ...

Kunz, Clayton Gregory

2012-01-01T23:59:59.000Z

273

Underwater Radiance Distributions Measured with Miniaturized Multispectral Radiance Cameras  

Science Conference Proceedings (OSTI)

Miniaturized radiance cameras measuring underwater multispectral radiances in all directions at high-radiometric accuracy (CE600) are presented. The camera design is described, as well as the main steps of its optical and radiometric ...

David Antoine; André Morel; Edouard Leymarie; Amel Houyou; Bernard Gentili; Stéphane Victori; Jean-Pierre Buis; Nicolas Buis; Sylvain Meunier; Marius Canini; Didier Crozel; Bertrand Fougnie; Patrice Henry

2013-01-01T23:59:59.000Z

274

Large scale structure from motion for autonomous underwater vehicle surveys  

E-Print Network (OSTI)

Our ability to image extended underwater scenes is severely limited by attenuation and backscatter. Generating a composite view from multiple overlapping images is usually the most practical and flexible way around this ...

Pizarro, Oscar

2004-01-01T23:59:59.000Z

275

An Autonomous Underwater Vehicle for the Study of Small Lakes  

Science Conference Proceedings (OSTI)

A small autonomous underwater vehicle (AUV) was designed and built to carry a wide variety of oceanographic sensors in the relatively benign lacustrine environment. PURLII navigates along preprogrammed paths for up to 3 h using compass, depth, ...

Bernard Laval; John S. Bird; Peter D. Helland

2000-01-01T23:59:59.000Z

276

Gabor Transform Application in Feature Description of Underwater Echo Signal  

Science Conference Proceedings (OSTI)

For the nonstationarity of target echo signals acquired by laser underwater target detecting system and the relevance between target echo signal and noise, in virtue of texture analysis of image processing, Gabor transform is used to localize the target ...

Shubin Yang; Wanlong Cui; Huaxi Wang

2009-12-01T23:59:59.000Z

277

State Estimation Strategies for Autonomous Underwater Vehicle Fish Tracking Applications  

E-Print Network (OSTI)

I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. Jun Zhou ii As the largest unexplored area on earth, the underwater world has unlimited attraction to marine scientists. Due to the complexity of the underwater environment and the limitations of human divers, underwater exploration has been facilitated by the use of submarines, Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs). In recent years, use of autonomous control systems being integrated with visual sensors has increased substantially, especially in marine applications involving guidance of AUVs. In this work, autonomous fish-tracking via AUV with vision servoing control system is studied with the purpose of assisting marine biologists in gathering detailed

Jun Zhou

2007-01-01T23:59:59.000Z

278

Imaging sonar-aided navigation for autonomous underwater harbor surveillance  

E-Print Network (OSTI)

In this paper we address the problem of drift-free navigation for underwater vehicles performing harbor surveillance and ship hull inspection. Maintaining accurate localization for the duration of a mission is important ...

Johannsson, Hordur

279

Large area 3-D reconstructions from underwater optical surveys  

E-Print Network (OSTI)

Robotic underwater vehicles are regularly performing vast optical surveys of the ocean floor. Scientists value these surveys since optical images offer high levels of detail and are easily interpreted by humans. Unfortunately, ...

Singh, Hanumant

280

Autonomous Depth Adjustment for Underwater Sensor Networks: Design and Applications  

E-Print Network (OSTI)

To fully understand the ocean environment requires sensing the full water column. Utilizing a depth adjustment system on an underwater sensor network provides this while also improving global sensing and communications. ...

Detweiler, Carrick

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Development of a snorkel for unmanned underwater vehicles  

E-Print Network (OSTI)

The development of unmanned underwater vehicles (UUV) has provided a bevy of opportunities for the exploration of the ocean. However, one limitation has kept UUVs from truly becoming mass produced, its limited range. The ...

Tia, Peter (Peter M.)

2012-01-01T23:59:59.000Z

282

Path planning of Autonomous Underwater Vehicles for adaptive sampling  

E-Print Network (OSTI)

This thesis develops new methods for path planning of Autonomous Underwater Vehicles for adaptive sampling. The problem is approached in an optimization framework and two methods are developed to solve it based on Mixed ...

Yilmaz, Namik Kemal, 1975-

2006-01-01T23:59:59.000Z

283

Dispersive waves generated by an underwater landslide  

E-Print Network (OSTI)

In this work we study the generation of water waves by an underwater sliding mass. The wave dynamics are assumed to fell into the shallow water regime. However, the characteristic wavelength of the free surface motion is generally smaller than in geophysically generated tsunamis. Thus, dispersive effects need to be taken into account. In the present study the fluid layer is modeled by the Peregrine system modified appropriately and written in conservative variables. The landslide is assumed to be a quasi-deformable body of mass whose trajectory is completely determined by its barycenter motion. A differential equation modeling the landslide motion along a curvilinear bottom is obtained by projecting all the forces acting on the submerged body onto a local moving coordinate system. One of the main novelties of our approach consists in taking into account curvature effects of the sea bed.

Dutykh, Denys; Beysel, Sonya; Shokina, Nina; Khakimzyanov, Gayaz

2011-01-01T23:59:59.000Z

284

Spectroscopic research of underwater electrical wire explosion  

Science Conference Proceedings (OSTI)

Results of spectroscopic research in the visible range of light of the radiation generated by underwater electrical wire explosions (UEWE) are presented. A pulsed generator with an output voltage of {approx}110 kV, current of {approx}70 kA, and rise time of {approx}60 ns was used for electrical explosion of Cu wires 0.1 mm in diameter and 50 mm in length. It was shown that UEWE is not governed by the 'polarity' effect, which plays an important role in electrical wire explosions in vacuum. The results of detailed space- and time-resolved spectroscopic measurements show that the radiation spectrum differs significantly of the spectrum expected from the exploding wire. A model is suggested based on the formation of a few {mu}m 'water' plasma layer in the vicinity of the exploding wire plasma which efficiently absorbs the radiation of the exploding wire.

Fedotov, A.; Sheftman, D.; Gurovich, V. Tz.; Efimov, S.; Bazilitski, G.; Krasik, Ya. E. [Physics Department, Technion-Israel Institute of Technology, 32000 Haifa (Israel); Oreshkin, V. I. [Institute of High Current Electronics, RAS, Tomsk (Russian Federation)

2008-08-15T23:59:59.000Z

285

Acoustic Microscopy Applications*  

Science Conference Proceedings (OSTI)

Figure: ...Fig. 17 A portion of the 160 mm 2 (0.25 in. 2 ) area of an alumina ceramic disk scanned by an acoustic microscope

286

Acoustics by additive manufacturing.  

E-Print Network (OSTI)

??This study focuses on exploring the merging field of additive manufacturing and acoustics and introduces a new type of sound absorber which is regulating performance… (more)

Setaki, F.

2012-01-01T23:59:59.000Z

287

Remote Underwater Characterization System - Innovative Technology Summary Report  

Science Conference Proceedings (OSTI)

Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The underwater characterization equipment is often required to operate at depths exceeding 20 ft (6.1 m) and in relatively confined or congested spaces. The typical baseline approach has been the use of radiation detectors and underwater cameras mounted on long poles, or stationary cameras with pan and tilt features mounted on the sides of the underwater facility. There is a perceived need for an inexpensive, more mobile method of performing close-up inspection and radiation measurements in confined spaces underwater. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available “Scallop” vehicle1, but has been modified by Department of Energy’s Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at Idaho National Engineering and environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a “head-tohead” fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations.

Willis, Walter David

1999-04-01T23:59:59.000Z

288

Feasibility of underwater welding of highly irradiated in-vessel components of boiling-water reactors: A literature review  

SciTech Connect

In February 1997, the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research (RES), initiated a literature review to assess the state of underwater welding technology. In particular, the objective of this literature review was to evaluate the viability of underwater welding in-vessel components of boiling water reactor (BWR) in-vessel components, especially those components fabricated from stainless steels that are subjected to high neutron fluences. This assessment was requested because of the recent increased level of activity in the commercial nuclear industry to address generic issues concerning the reactor vessel and internals, especially those issues related to repair options. This literature review revealed a preponderance of general information about underwater welding technology, as a result of the active research in this field sponsored by the U.S. Navy and offshore oil and gas industry concerns. However, the literature search yielded only a limited amount of information about underwater welding of components in low-fluence areas of BWR in-vessel environments, and no information at all concerning underwater welding experiences in high-fluence environments. Research reported by the staff of the U.S. Department of Energy (DOE) Savannah River Site and researchers from the DOE fusion reactor program proved more fruitful. This research documented relevant experience concerning welding of stainless steel materials in air environments exposed to high neutron fluences. It also addressed problems with welding highly irradiated materials, and primarily attributed those problems to helium-induced cracking in the material. (Helium is produced from the neutron irradiation of boron, an impurity, and nickel.) The researchers found that the amount of helium-induced cracking could be controlled, or even eliminated, by reducing the heat input into the weld and applying a compressive stress perpendicular to the weld path.

Lund, A.L.

1997-11-01T23:59:59.000Z

289

Random matrix theory for underwater sound propagation  

E-Print Network (OSTI)

Ocean acoustic propagation can be formulated as a wave guide with a weakly random medium generating multiple scattering. Twenty years ago, this was recognized as a quantum chaos problem, and yet random matrix theory, one pillar of quantum or wave chaos studies, has never been introduced into the subject. The modes of the wave guide provide a representation for the propagation, which in the parabolic approximation is unitary. Scattering induced by the ocean's internal waves leads to a power-law random banded unitary matrix ensemble for long-range deep ocean acoustic propagation. The ensemble has similarities, but differs, from those introduced for studying the Anderson metal-insulator transition. The resulting long-range propagation ensemble statistics agree well with those of full wave propagation using the parabolic equation.

Katherine C. Hegewisch; Steven Tomsovic

2011-04-20T23:59:59.000Z

290

Underwater Explosive Shock Consolidation of Nanocomposite Pr2Fe14B/-Fe Magnetic Powders  

E-Print Network (OSTI)

PR O O FS Underwater Explosive Shock Consolidation of Nanocomposite Pr2Fe14B/-Fe Magnetic Powders; Accepted January 6, 2005) Keywords: explosive compaction, underwater shock wave, nanocomposites, magnetic

Liu, J. Ping

291

Design of an autonomous underwater vehicle : vehicle tracking and position control.  

E-Print Network (OSTI)

??This project proposes the development of an autonomous underwater vehicle that can be used to perform underwater research missions..The vehicle can be pre-programmed to complete… (more)

Holtzhausen, Servaas.

2010-01-01T23:59:59.000Z

292

Open loop performance of a biomimetic flapping foil autonomous underwater vehicle  

E-Print Network (OSTI)

Flapping foil propulsion is emerging as an alternative to conventional propulsion for underwater vehicles. MIT's Biomimetic Flapping Foil Autonomous Underwater Vehicle is a prototype vehicle that uses four three-dimensional ...

Wolf, Malima Isabelle, 1981-

2006-01-01T23:59:59.000Z

293

Neutrino Detection, Position Calibration and Marine Science with Acoustic Arrays in the Deep Sea  

E-Print Network (OSTI)

Arrays of acoustic receivers are an integral part of present and potential future Cherenkov neutrino telescopes in the deep sea. They measure the positions of individual detector elements which vary with time as an effect of undersea currents. At the same time, the acoustic receivers can be employed for marine science purposes, in particular for monitoring the ambient noise environment and the signals emitted by the fauna of the sea. And last but not least, they can be used for studies towards acoustic detection of ultra-high-energy neutrinos. Measuring acoustic pressure pulses in huge underwater acoustic arrays with an instrumented volume of the order of 100 km^3 is a promising approach for the detection of cosmic neutrinos with energies exceeding 1 EeV. Pressure signals are produced by the particle cascades that evolve when neutrinos interact with nuclei in water, and can be detected over large distances in the kilometre range. In this article, the status of acoustic detection will be reviewed and plans for...

Lahmann, Robert

2013-01-01T23:59:59.000Z

294

Acoustic cooling engine  

DOE Patents (OSTI)

An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

Hofler, Thomas J. (Los Alamos, NM); Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Santa Fe, NM); Migliori, Albert (Santa Fe, NM)

1988-01-01T23:59:59.000Z

295

Robust Vision-based Underwater Target Identification & Homing Using Self-Similar  

E-Print Network (OSTI)

Robust Vision-based Underwater Target Identification & Homing Using Self-Similar Landmarks Amaury. Next generation Autonomous Underwater Vehicles (AUVs) will be re- quired to robustly identify underwater targets for tasks such as inspection, locali- sation and docking. Given their often unstructured

Paris-Sud XI, Université de

296

The DRL Underwater Sensor Network: Supporting Dual Communications, Sensing, and Mobility  

E-Print Network (OSTI)

The DRL Underwater Sensor Network: Supporting Dual Communications, Sensing, and Mobility Iuliu Vasilescu, Carrick Detweiler and Daniela Rus We propose to demonstrate the underwater sensor network are anchored with weights and form a static underwater network. This network self-localizes a range based 3D

Farritor, Shane

297

Long-term underwater camera surveillance for monitoring and analysis of fish populations  

E-Print Network (OSTI)

Long-term underwater camera surveillance for monitoring and analysis of fish populations Bastiaan J Laboratories, Taiwan Abstract Long-term monitoring of the underwater environ- ment is still labour intensive work. Using underwater surveillance cameras to monitor this environment has the potential advantage

Fisher, Bob

298

A Statistical Learning-Based Method for Color Correction of Underwater Images  

E-Print Network (OSTI)

A Statistical Learning-Based Method for Color Correction of Underwater Images Luz A. Torres the problem of color correction of un- derwater images using statistical priors. Underwater images present by using a non-parametric sampling procedure. Experimental results on a variety of underwater scenes

Dudek, Gregory

299

Using a High Order Sliding Modes for diving control a torpedo Autonomous Underwater Vehicle  

E-Print Network (OSTI)

Using a High Order Sliding Modes for diving control a torpedo Autonomous Underwater Vehicle T Underwater Vehicle AUV is not a trivial task, due to: Parameter uncertainties (as added mass, hydrodynamic underwater robots are basically two: PD [2] [10] and Sliding Modes Control (SMC) [6] [11]. These algorithms

Paris-Sud XI, Université de

300

Stability Analysis of a New Extended L1 Controller with Experimental Validation on an Underwater Vehicle  

E-Print Network (OSTI)

Stability Analysis of a New Extended L1 Controller with Experimental Validation on an Underwater on an underwater vehicle subjected to a varying trajectory under several dis- turbances are then displayed. Moreover, experimental results are provided on an underwater vehicle in depth. The robot is expected

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Abstract-Homing and navigation capabilities are essential for many Autonomous Underwater Vehicle  

E-Print Network (OSTI)

Abstract- Homing and navigation capabilities are essential for many Autonomous Underwater Vehicle, speed bias and underwater currents affect dead-reckoning measurements. All operation need to have INTRODUCTION Actually, there is a real challenge on application of Autonomous Underwater Vehicle, particularly

Paris-Sud XI, Université de

302

Underwater temporary threshold shift in pinnipeds: Effects of noise level and duration  

E-Print Network (OSTI)

Underwater temporary threshold shift in pinnipeds: Effects of noise level and duration David Kastak psychophysical techniques were used to evaluate the residual effects of underwater noise on the hearing , amplified Realis- tic MPA-20 , and projected from one of two underwater transducers NUWC J-9 or Lubell

Reichmuth, Colleen

303

Time-critical Underwater Sensor Diffusion with No Proactive Exchanges and Negligible Reactive Floods  

E-Print Network (OSTI)

Time-critical Underwater Sensor Diffusion with No Proactive Exchanges and Negligible Reactive multi-hop ad hoc routing in a scalable Underwater Sensor Network (UWSN), which is a novel network in the challenging new underwater environment. Unlike the terrestrial scenarios, on-demand flooding cannot be both

Park, Joon-Sang

304

PARTICLE FILTERING AND CRAM ER-RAO LOWER BOUND FOR UNDERWATER NAVIGATION  

E-Print Network (OSTI)

PARTICLE FILTERING AND CRAM ´ER-RAO LOWER BOUND FOR UNDERWATER NAVIGATION Rickard Karlsson, Fredrik-mail: {rickard,fredrik}@isy.liu.se Tobias Karlsson Saab Bofors Underwater Systems Box 910 SE-591 29 Motala relying on a dig- ital underwater terrain map and sonar measurements. The method is applicable for both

Gustafsson, Fredrik

305

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP  

E-Print Network (OSTI)

Hydrobiologia vol. 65, I, pag. 65-68, 1979 A SIZE SELECTIVE UNDERWATER LIGHT TRAP R. B. AIKEN underwater light trap isdescribed. Trap records indicate that the trap iseffective in taking a wide variety. (1955) described the construction and operation of an underwater light trap. Their records indi- cate

Aiken, Ron

306

From PD to Nonlinear Adaptive Depth-Control of a Tethered Autonomous Underwater Vehicle  

E-Print Network (OSTI)

From PD to Nonlinear Adaptive Depth-Control of a Tethered Autonomous Underwater Vehicle D and an adaptive nonlinear state feedback one, both applied on a tethered autonomous underwater vehicle. The aim performed using each of the above mentioned control laws. Keywords: Underwater robotics, Depth control

Paris-Sud XI, Université de

307

Underwater temporary threshold shift induced by octave-band noise in three species of pinniped  

E-Print Network (OSTI)

Underwater temporary threshold shift induced by octave-band noise in three species of pinniped at center frequency . Each subject was trained to dive into a noise field and remain stationed underwater airborne. When human divers were tested underwater, for instance, the resultant levels of TTS were much

Reichmuth, Colleen

308

In-air and underwater hearing sensitivity of a northern elephant seal (Mirounga angustirostris)  

E-Print Network (OSTI)

In-air and underwater hearing sensitivity of a northern elephant seal (Mirounga angustirostris) D. Kastak and R.J. Schusterman Abstract: In-air and underwater sound detection thresholds were obtainedPa). The upper frequency limit in air was approximately 20 kHz. The underwater audiogram is similar to those

Reichmuth, Colleen

309

Underwater Networking Research at USC/ISI John Heidemann Wei Ye Jack Wills  

E-Print Network (OSTI)

Underwater Networking Research at USC/ISI John Heidemann Wei Ye Jack Wills {johnh. By comparison, underwater sensing today is often expensive, sparsely deployed, and wired, or with very limited of terrestrial sensor networks underwater. To this end we are developing new approaches for hardware, with a new

Heidemann, John

310

Underwater Bomb Trajectory Prediction for Stand-off Assault (Mine/IED) Breaching Weapon  

E-Print Network (OSTI)

Underwater Bomb Trajectory Prediction for Stand-off Assault (Mine/IED) Breaching Weapon Fuse to determine accurately underwater (full-size) bomb trajectory path so that the final detonation position of a six degrees of freedom (6-DOF) model to predict underwater high-speed bomb trajectory and orientation

Chu, Peter C.

311

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size  

E-Print Network (OSTI)

Underwater microscope for measuring spatial and temporal changes in bed-sediment grain size David M by Elsevier B.V. Keywords: Underwater microscope; Bed sediment; Grain size; In situ measurement; Colorado counts on a small subset of processed images. 2.3. Underwater microscope hardware Digital images of bed

312

MAPPING OUR UNDERWATER MARINE RESOURCES The MapCoast and BayMap Partnerships  

E-Print Network (OSTI)

MAPPING OUR UNDERWATER MARINE RESOURCES The MapCoast and BayMap Partnerships BAYMAP: CHARTING communities and underwater archaeological sites in a readily accessible GIS format. An interdisciplinary team underwater resources, including bathymetry, habitat, geology, soils/ sediment, and archeological resources

Wang, Y.Q. "Yeqiao"

313

Towards Optimal Broadcasting Policies for HARQ based on Fountain Codes in Underwater Networks  

E-Print Network (OSTI)

Towards Optimal Broadcasting Policies for HARQ based on Fountain Codes in Underwater Networks Paolo technique for the transmission over underwater channels as their performance, in terms of delay, reliability on the topic and encourages us towards the design of practical HARQ protocols for the underwater medium. Index

Rossi, Michele

314

HydroNode: an underwater sensor node prototype for monitoring hydroelectric reservoirs  

Science Conference Proceedings (OSTI)

The research of underwater sensor networks (UWSNs) is gaining attention due to its possible applications in many scenarios, such as ecosystem preservation, disaster prevention, oil and gas exploration and freshwater reservoirs management. The main elements ... Keywords: hydroelectric, monitoring, reservoirs, underwater sensor networks, underwater sensor node

Luiz F. M. Vieira; Marcos A. M. Vieira; David Pinto; José Augusto M. Nacif; Sadraque S. Viana; Alex B. Vieira

2012-11-01T23:59:59.000Z

315

Effect of inelastic scattering on underwater daylight in the ocean: model evaluation,  

E-Print Network (OSTI)

optical processes affecting underwater daylight are mathematically described by the radiativeEffect of inelastic scattering on underwater daylight in the ocean: model evaluation, validation capable of simulating underwater daylight in the ocean is presented. The main focus is on gelbstoff

Oldenburg, Carl von Ossietzky Universität

316

Digital RAC with a disturbance observer for underwater vehicle-manipulator systems  

Science Conference Proceedings (OSTI)

Most control methods of underwater vehiclemanipulator systems (UVMS) are based on the computed torque method that is used for underwater robotic vehicles. We have proposed a resolved acceleration control (RAC) method for UVMS. In this article, we propose ... Keywords: Digital control, Disturbance observer, Manipulator, Underwater robot

Shinichi Sagara; Takashi Yatoh; Tomoaki Shimozawa

2010-12-01T23:59:59.000Z

317

Acoustical heat pumping engine  

DOE Patents (OSTI)

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

1983-08-16T23:59:59.000Z

318

Acoustical heat pumping engine  

DOE Patents (OSTI)

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1983-08-16T23:59:59.000Z

319

Acoustic well cleaner  

DOE Patents (OSTI)

A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

Maki, Jr., Voldi E. (11904 Bell Ave., Austin, TX 78759-2415); Sharma, Mukul M. (Dept. of Petroleum Engr. Univ. of Texas, Austin, TX 78712)

1997-01-21T23:59:59.000Z

320

Sensitivity of ray dynamics in an underwater sound channel to vertical scale of longitudinal sound-speed variations  

E-Print Network (OSTI)

We investigate sound ray propagation in a range-dependent underwater acoustic waveguide. Our attention is focused on sensitivity of ray dynamics to the vertical structure of a sound-speed perturbation induced by ocean internal waves. Two models of longitudinal sound-speed variations are considered: a periodic inhomogeneity and a stochastic one. It is found that vertical oscillations of a sound-speed perturbation can affect rays in a resonant manner. Such resonances give rise to chaos in certain regions of phase space. It is shown that stability of steep rays, being observed in experiments, is connected with suppression of resonances in the case of small-scale vertical sound-speed oscillations.

D. V. Makarov; M. Yu. Uleysky; M. Yu. Martynov

2005-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Acoustic Logs At The Needles Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

The Needles Area (DOE GTP) Exploration Activity Details Location The Needles Area Exploration Technique Acoustic Logs Activity Date Usefulness not indicated DOE-funding Unknown...

322

Space, time and acoustics  

E-Print Network (OSTI)

This thesis describes the development of new concepts in acoustical analysis from their inception to implementation as a computer design tool. Research is focused on a computer program which aids the designer to visually ...

Thompson, Philip R. Z. (Philip Reed Zane)

1988-01-01T23:59:59.000Z

323

Atmospheric Acoustic Minisounder  

Science Conference Proceedings (OSTI)

An improved version of a monostatic acoustic minisounder for the investigation of the structure and dynamics of the lower boundary layer, operating at high frequencies and equipped with a specially designed micro-antenna and advanced electronic ...

D. N. Asimakopoulos; C. G. Helmis; G. J. Stephanou

1987-06-01T23:59:59.000Z

324

Spacetime transformation acoustics  

E-Print Network (OSTI)

A recently proposed analogue transformation method has allowed the extension of transformation acoustics to general spacetime transformations. We analyze here in detail the differences between this new analogue transformation acoustics (ATA) method and the standard one (STA). We show explicitly that STA is not suitable for transformations that mix space and time. ATA takes as starting point the acoustic equation for the velocity potential, instead of that for the pressure as in STA. This velocity-potential equation by itself already allows for some transformations mixing space and time, but not all of them. We explicitly obtain the entire set of transformations that do not leave its form invariant. It is in these cases that ATA shows its true potential, allowing for building a transformation acoustics method that enables the full range of spacetime transformations. We provide an example of an important transformation which cannot be achieved with STA. Using this transformation, we design and simulate an acous...

García-Meca, C; Barceló, C; Jannes, G; Sánchez-Dehesa, J; Martínez, A

2013-01-01T23:59:59.000Z

325

Automatic acoustic guitar tuner  

E-Print Network (OSTI)

Acoustic guitar musicians tune their instruments by using a conventional tuner. Individuals pluck the string and the conventional tuner indicates whether the note is sharp or flat. The musician then has to wind the string ...

Bocanegra, Alfredo

2005-01-01T23:59:59.000Z

326

MHK Technologies/Underwater Electric Kite Turbines | Open Energy  

Open Energy Info (EERE)

Underwater Electric Kite Turbines Underwater Electric Kite Turbines < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Underwater Electric Kite Turbines.jpg Technology Profile Primary Organization UEK Corporation Project(s) where this technology is utilized *MHK Projects/Atchafalaya River Hydrokinetic Project II *MHK Projects/Chitokoloki Project *MHK Projects/Coal Creek Project *MHK Projects/Half Moon Cove Tidal Project *MHK Projects/Indian River Tidal Hydrokinetic Energy Project *MHK Projects/Luangwa Zambia Project *MHK Projects/Minas Basin Bay of Fundy Commercial Scale Demonstration *MHK Projects/Passamaquoddy Tribe Hydrokinetic Project *MHK Projects/Piscataqua Tidal Hydrokinetic Energy Project *MHK Projects/UEK Yukon River Project Technology Resource

327

Keyboard acoustic emanations revisited  

Science Conference Proceedings (OSTI)

We examine the problem of keyboard acoustic emanations. We present a novel attack taking as input a 10-minute sound recording of a user typing English text using a keyboard, and then recovering up to 96% of typed characters. There is no need for a labeled ... Keywords: HMM, acoustic emanations, cepstrum, computer security, electronic eavesdropping, hidden Markov models, human factors, keyboards, learning theory, privacy, signal analysis

Li Zhuang; Feng Zhou; J. D. Tygar

2005-11-01T23:59:59.000Z

328

Keyboard acoustic emanations revisited  

Science Conference Proceedings (OSTI)

We examine the problem of keyboard acoustic emanations. We present a novel attack taking as input a 10-minute sound recording of a user typing English text using a keyboard and recovering up to 96% of typed characters. There is no need for training ... Keywords: Computer security, HMM, acoustic manations, cepstrum, electronic eavesdropping, hidden markov models, human factors, keyboards, learning theory, privacy, signal analysis

Li Zhuang; Feng Zhou; J. D. Tygar

2009-10-01T23:59:59.000Z

329

Design of a low-cost underwater acoustic modem for short- range sensor networks  

E-Print Network (OSTI)

for cost, energy consumption or deployment time forfor cost, energy consumption or deployment time for a givenbattery energy and cost for a deployment time of 6 months

Benson, Bridget

2010-01-01T23:59:59.000Z

330

Design of a low-cost underwater acoustic modem for short- range sensor networks  

E-Print Network (OSTI)

Table 7.3: FPGA Power Consumption Device Q Pwr D Pwr T Pwr (in device families known for their low power consumption (

Benson, Bridget

2010-01-01T23:59:59.000Z

331

Design of a low-cost underwater acoustic modem for short- range sensor networks  

E-Print Network (OSTI)

following subsection. The battery cost and energy capacityfor minimizing battery energy and cost for a deployment timea modem, the cost of an individual battery, and the energy

Benson, Bridget

2010-01-01T23:59:59.000Z

332

Design of a low-cost underwater acoustic modem for short- range sensor networks.  

E-Print Network (OSTI)

??Small, dense, wireless sensor networks are beginning to revolutionize our understanding of the physical world by providing fine resolution sampling of the surrounding environment. The… (more)

Benson, Bridget

2010-01-01T23:59:59.000Z

333

Wave localization as a manifestation of ray chaos in underwater acoustics  

E-Print Network (OSTI)

Wave chaos is demonstrated by studying a wave propagation in a periodically corrugated wave-guide. In the limit of a short wave approximation (SWA) the underlying description is related to the chaotic ray dynamics. In this case the control parameter of the problem is characterized by the corrugation amplitude and the SWA parameter. The considered model is fairly suitable and tractable for the analytical analysis of a wave localization length. The number of eigenmodes characterized the width of the localized wave packet is estimated analytically.

A. Iomin; Yu. Bliokh

2007-06-03T23:59:59.000Z

334

Performance analysis of Non Linear Filtering Algorithms for underwater images  

E-Print Network (OSTI)

Image filtering algorithms are applied on images to remove the different types of noise that are either present in the image during capturing or injected in to the image during transmission. Underwater images when captured usually have Gaussian noise, speckle noise and salt and pepper noise. In this work, five different image filtering algorithms are compared for the three different noise types. The performances of the filters are compared using the Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE). The modified spatial median filter gives desirable results in terms of the above two parameters for the three different noise. Forty underwater images are taken for study.

Padmavathi, Dr G; Kumar, Mr M Muthu; Thakur, Suresh Kumar

2009-01-01T23:59:59.000Z

335

An overview of the internet of underwater things  

Science Conference Proceedings (OSTI)

Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas. Ocean temperatures determine climate and wind patterns that affect life on land. Freshwater ... Keywords: Applications, Architecture, Internet of underwater things, Research challenges

Mari Carmen Domingo

2012-11-01T23:59:59.000Z

336

Automatic fish classification for underwater species behavior understanding  

Science Conference Proceedings (OSTI)

The aim of this work is to propose an automatic fish classification system that operates in the natural underwater environment to assist marine biologists in understanding subehavior. Fish classification is performed by combining two types of features: ... Keywords: fish species description and classification

Concetto Spampinato; Daniela Giordano; Roberto Di Salvo; Yun-Heh Jessica Chen-Burger; Robert Bob Fisher; Gayathri Nadarajan

2010-10-01T23:59:59.000Z

337

Color-accurate underwater imaging using perceptual adaptive illumination  

Science Conference Proceedings (OSTI)

Capturing color in water is challenging due to the heavy non-uniform attenuation of light in water across the visible spectrum, which results in dramatic hue shifts toward blue. Yet observing color in water is important for monitoring and surveillance ... Keywords: Accurate colors, Adaptive illumination, Color rendering index, Underwater imaging

Iuliu Vasilescu; Carrick Detweiler; Daniela Rus

2011-10-01T23:59:59.000Z

338

Underwater 3D Mapping: Experiences and Lessons learned  

Science Conference Proceedings (OSTI)

This paper provides details on the development of a tool to aid in 3D coral reef mapping designed to be operated by a single diver and later integrated into an autonomous robot. We discuss issues that influence the deployment and development of underwater ...

Andrew Hogue; Andrew German; James Zacher; Michael Jenkin

2006-06-01T23:59:59.000Z

339

Underwater Noise and the Distribution of Snapping Shrimp with Special Reference to the Asiatic and the Southwest and Central Pacific Areas  

E-Print Network (OSTI)

Six - Section 6.1 UNDERWATER NOISE AND TEE DISTRIBUTION OFOfficor, u. s. NavY Underwater Sound La.borntory COEUTCH - (I D' E NT I N A. ~ . UNDERWATER NOISE Ai'ID TEE DISTRIBUTION

Johnson, Martin W

1944-01-01T23:59:59.000Z

340

Acoustic Imaging Suite  

INL’s acoustic imaging technology improves methods of capturing moving images of a specified object by using a photorefractive effect to produce a full-field image of the object without using a probe to perform a full scan of the object. INL ...

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Acoustic Logs At Coso Geothermal Area (1977) | Open Energy Information  

Open Energy Info (EERE)

Coso Geothermal Area (1977) Coso Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Acoustic Logs At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Acoustic Logs Activity Date 1977 Usefulness not indicated DOE-funding Unknown Notes Acoustic logs indicate fractured rock and potentially permeable zones. References Galbraith, R. M. (1 May 1978) Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Goranson, C.; Schroeder, R. (1 June 1978) Static downhole characteristics of well CGEH-1 at Coso Hot Springs, China Lake, California Retrieved from "http://en.openei.org/w/index.php?title=Acoustic_Logs_At_Coso_Geothermal_Area_(1977)&oldid=510216"

342

The Sound Emission Board of the KM3NeT Acoustic Positioning System  

E-Print Network (OSTI)

We describe the sound emission board proposed for installation in the acoustic positioning system of the future KM3NeT underwater neutrino telescope. The KM3NeT European consortium aims to build a multi-cubic kilometre underwater neutrino telescope in the deep Mediterranean Sea. In this kind of telescope the mechanical structures holding the optical sensors, which detect the Cherenkov radiation produced by muons emanating from neutrino interactions, are not completely rigid and can move up to dozens of meters in undersea currents. Knowledge of the position of the optical sensors to an accuracy of about 10 cm is needed for adequate muon track reconstruction. A positioning system based on the acoustic triangulation of sound transit time differences between fixed seabed emitters and receiving hydrophones attached to the kilometre-scale vertical flexible structures carrying the optical sensors is being developed. In this paper, we describe the sound emission board developed in the framework of KM3NeT project, whi...

Llorens, C D; Sogorb, T; Bou--Cabo, M; Martínez-Mora, J A; Larosa, G; Adrián-Martínez, S

2012-01-01T23:59:59.000Z

343

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ical-exclusion-determination Download CX-005561: Categorical Exclusion Determination Underwater Active Acoustic Monitoring Support for Marine Hydrokinetic Energy Projects CX(s)...

344

Acoustics 2000 1 Acoustic Propagation Prediction in Shallow Water  

E-Print Network (OSTI)

the experiment location. Light bulbs in particular have been the topic of interest as an implosive underwater) will be lost to an absorptive seabed. The results of the propagation measurements performed using light bulbs were a 20-cui air gun and imploding sources comprising 60W and 75W light globes and purpose built

345

Trajectory Design and Implementation for Multiple Autonomous Underwater Vehicles Based on Ocean Model Predictions  

E-Print Network (OSTI)

Underwater Vehicles Based on Ocean Model Predictions Ryan N.Trajectory Design based on Ocean Model Predictions PredictEffective tracking of ocean features Gather specific in situ

2009-01-01T23:59:59.000Z

346

The development of Zero-G class underwater robots: unrestricted attitude control using control moment gyros.  

E-Print Network (OSTI)

??The ‘Zero-G’ is designated as a new class of underwater robot that is capable of unrestricted attitude control. A novel control scheme based on internal… (more)

Thornton, Blair

2006-01-01T23:59:59.000Z

347

P2-28: Characterization of Pores and Cracks in Underwater Welds ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Underwater shielded metal arc wet welding with coated electrodes is a common procedure for in situ repair of structural parts of offshore oil ...

348

A data link layer in support of swarming of autonomous underwater vehicles.  

E-Print Network (OSTI)

??Communication underwater is challenging because of the inherent characteristics of the media. First, common radio frequency (RF) signals utilized in wireless communications cannot be used… (more)

Jabba Molinares, Daladier

2009-01-01T23:59:59.000Z

349

Caloric expenditure and substrate utilization in underwater treadmill running versus land-based treadmill running.  

E-Print Network (OSTI)

??The objective of this study is to compare the caloric expenditure and oxidative sources of underwater treadmill running and land-based treadmill running at maximal and… (more)

Schaal, Courtney

2009-01-01T23:59:59.000Z

350

An analysis of underwater habitats a development of the outline for aquatectural graphic standards.  

E-Print Network (OSTI)

??In addition to many forms of land-based architecture in this world, there are several instances of underwater habitats. These habitats have implications for space exploration… (more)

Riggin, Daniel

2009-01-01T23:59:59.000Z

351

Decentralized sensor placement and mobile localization on an underwater sensor network with depth adjustment capabilities.  

E-Print Network (OSTI)

??Over 70% of our planet is covered by water. It is widely believed that the underwater world holds ideas and resources that will fuel much… (more)

Detweiler, Carrick (Carrick James)

2010-01-01T23:59:59.000Z

352

On the detection of relativistic magnetic monopoles by deep underwater and underice neutrino telescopes  

E-Print Network (OSTI)

I present here some reflections and very speculative remarks on the detection of relativistic magnetic monopoles by currently operating deep underwater/ice neutrino telescopes.

B. K. Lubsandorzhiev

2005-06-13T23:59:59.000Z

353

Autonomous adaptive environmental assessment and feature tracking via autonomous underwater vehicles  

E-Print Network (OSTI)

In the underwater environment, spatiotemporally dynamic environmental conditions pose challenges to the detection and tracking of hydrographic features. A useful tool in combating these challenge is Autonomous Adaptive ...

Petillo, Stephanie Marie

354

Hydrodynamic Modeling for Autonomous Underwater Vehicles Using Computational and Semi-Empirical Methods.  

E-Print Network (OSTI)

??Buoyancy driven underwater gliders, which locomote by modulating their buoyancy and their attitude with moving mass actuators and inflatable bladders, are proving their worth as… (more)

Geisbert, Jesse Stuart

2007-01-01T23:59:59.000Z

355

Path planning methods for Autonomous Underwater Vehicles; Path planning methods for AUVs.  

E-Print Network (OSTI)

??From naval operations to ocean science missions, the importance of autonomous vehicles is increasing with the advances in underwater robotics technology. Due to the dynamic… (more)

Yi?it, Konuralp

2011-01-01T23:59:59.000Z

356

Control and guidance systems for the navigation of a biomimetic autonomous underwater vehicle.  

E-Print Network (OSTI)

??The field of Autonomous Underwater Vehicles (AUVs) has increased dramatically in size and scope over the past three decades. Application areas for AUVs are numerous… (more)

Tonello, Alberto

2011-01-01T23:59:59.000Z

357

Virtual Long Baseline (VLBL) autonomous underwater vehicle navigation using a single transponder .  

E-Print Network (OSTI)

??This thesis presents a simulation of autonomous underwater vehicle navigation using a single transponder to create a virtual long baseline (VLBL). Similarly to LBL systems,… (more)

LaPointe, Cara E. G.

2006-01-01T23:59:59.000Z

358

Strongly coupled copper plasma generated by underwater electrical wire explosion  

Science Conference Proceedings (OSTI)

A number of theoretical approaches to the analysis of the parameters of a discharge channel consisting of strongly coupled plasma generated in the process of underwater electrical wire explosion are presented. The analysis is based on experimental results obtained from discharges employing Cu wire. The obtained experimental data included electrical measurements and optical observations from which information about the dynamics of the water flow was extrapolated. Numerical calculation based on a 1D magnetohydrodynamic model was used to simulate the process of underwater wire explosion. A wide range conductivity model was applied in this calculation and good agreement with a set of experimental data was obtained. A method of determining the average temperature of the discharge channel based on this model and experimental results is proposed, and the limits of this method's applicability are discussed.

Grinenko, A.; Gurovich, V.Tz.; Saypin, A.; Efimov, S.; Krasik, Ya.E.; Oreshkin, V.I. [Physics Department, Technion, 32000 Haifa (Israel); Institute of High Current Electronics, SB RAN, 634055 Tomsk (Russian Federation)

2005-12-15T23:59:59.000Z

359

Welding and Repair Technology Center: Underwater Laser Welding Studies  

Science Conference Proceedings (OSTI)

Repair of internal reactor components has been a continuing challenge for the nuclear industry. High radiation levels, underwater environment, and altered material weldability have made traditional repair methods more difficult to use for internal component repair. One of the key issues is to make seal-weld repairs on cracks that might exist due to stress corrosion or fatigue. Sealing of these cracks by welding might be necessary to maintain pressure boundary or flow requirements. During this research pr...

2009-12-21T23:59:59.000Z

360

Underwater photomosaic system $40,000 Sandin is working to develop a new tool to take large-scale  

E-Print Network (OSTI)

Underwater photomosaic system $40,000 Sandin is working to develop a new tool to take large-scale photographs of the underwater environment. The effort comes in capturing many hi-resolution images

Russell, Lynn

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Acoustic paramagnetic logging tool  

DOE Patents (OSTI)

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

Vail, III, William B. (Bothell, WA)

1988-01-01T23:59:59.000Z

362

Cylindrical Acoustic Levitator/Concentrator  

NLE Websites -- All DOE Office Websites (Extended Search)

Cylindrical Acoustic Levitator/Concentrator Cylindrical Acoustic Levitator/Concentrator Cylindrical Acoustic Levitator/Concentrator A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. Available for thumbnail of Feynman Center (505) 665-9090 Email Cylindrical Acoustic Levitator/Concentrator A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that

363

Reduction of unsteady underwater propeller forces via active tail articulation  

E-Print Network (OSTI)

This study investigates the use of biologically-inspired tail articulation as a means to reduce unsteady propeller forces and by extension, noise due to stator wake blade interaction. This study is experimental in nature ...

James, Richard A. (Richard Alexander), 1982-

2006-01-01T23:59:59.000Z

364

Active control of underwater propulsor using shape memory alloys  

E-Print Network (OSTI)

The development of a leading edge propeller blade reconfiguration system using Shape Memory Allow (SMA) muscles is presented. This work describes the design and testing of a leading edge flap, which is used to alter the local camber of a propeller blade. The leading edge flap is deflected by SMA wires housed in the blade and maintained in a fixed position with a shaft locking and releasing mechanism. A locking and releasing mechanism is utilized so that constant actuation of the SMAs is not required to maintain leading edge deflection. The profile at 70% span of the propeller blade was used to create a two-dimensional blade for leading edge flap design implementation and load testing. Deflection of up to five degrees was obtained with the final design of the leading edge flap and locking and releasing mechanism. The SMA muscles used to deflect the leading edge were actuated electronically through resistive heating and were controlled by a proportional/integral gain control algorithm with closed-loop feedback from a linear displacement sensor within the blade. With the final design of the leading edge flap and locking and releasing mechanism, a preliminary design for a three-dimensional propeller was created.

Wasylyszyn, Jonathan Allen

2005-12-01T23:59:59.000Z

365

Acoustic Enhancement of Photodetecting Devices  

for suspect materials, to advanced weapons guidance. Using a high Q acoustic resonator, the invention increases the sensitivity of the detectors by an order of

366

Cylindrical Acoustic Levitator/Concentrator  

NLE Websites -- All DOE Office Websites (Extended Search)

A low-power, inexpensive acoustic apparatus for levitation andor concentration of aerosols and small liquidsolid samples having particulates up to several millimeters in...

367

Acoustic Character Of Hydraulic Fractures In Granite  

E-Print Network (OSTI)

Hydraulic fractures in homogeneous granitic rocks were logged with conventional acoustic-transit-time, acoustic-waveform, and acoustic-televiewer logging systems. Fractured intervals ranged in depth from 45 to 570m. and ...

Paillet, Frederick I.

1983-01-01T23:59:59.000Z

368

BUILDING UNDERWATER AD-HOC NETWORKS AND SENSOR NETWORKS FOR LARGE SCALE REAL-TIME AQUATIC APPLICATIONS  

E-Print Network (OSTI)

BUILDING UNDERWATER AD-HOC NETWORKS AND SENSOR NETWORKS FOR LARGE SCALE REAL-TIME AQUATIC, CT 06269 Gainesville, FL 32611 Abstract-- Large-scale Underwater Ad-hoc Networks (UANET) and Underwater Sensor Networks (UWSN) are novel networking paradigms to explore the uninhabited oceans. How- ever

Cui, Jun-Hong

369

626 IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 37, NO. 4, OCTOBER 2012 A Novel Blending Technique for Underwater  

E-Print Network (OSTI)

for Underwater Gigamosaicing Ricard Prados, Rafael Garcia, Nuno Gracias, Javier Escartín, and László Neumann underwater photomosaics to small areas de- spite the hundreds of thousands of square meters that modern sur- veys can cover. Large underwater photomosaics are increasingly in demand for the characterization

Escartin, Javier

370

An Underwater Communication and Sensing Testbed in Marina del Rey Andrew Goodney, Young H. Cho, John Heidemann, John Wroclawski  

E-Print Network (OSTI)

An Underwater Communication and Sensing Testbed in Marina del Rey Andrew Goodney, Young H. Cho, and communication underwater is increasingly important to scientists who study the oceans, rivers, and lakes, as government and industry seek to observe, protect, exploit, and control resources underwater. With growing

Heidemann, John

371

A Novel Application of Multivariable L1 Adaptive Control : from Design to Real-Time Implementation on an Underwater Vehicle  

E-Print Network (OSTI)

on an Underwater Vehicle Divine Maalouf1 Vincent Creuze1 and Ahmed Chemori1 Abstract-- This paper presents time in the field of underwater vehicles control. This paper summarizes the implementation and experimental results obtained on a modified version of the AC-ROV underwater vehicle. Various experimental

Paris-Sud XI, Université de

372

Underwater Unmanned Vehicle Boeing gave us the opportunity to compete against the Electrical Engineering Dept. The competition was  

E-Print Network (OSTI)

Underwater Unmanned Vehicle Overview Boeing gave us the opportunity to compete against Underwater Unmanned Vehicles. Basically we had to build remote controlled submarines from the ground up. Objectives To design a Underwater Unmanned Vehicle that meets the following Specs: Has an internal Ballast

Demirel, Melik C.

373

1 Underwater 3D SLAM through Entropy Minimization J.M. Sez, A. Hogue, F. Escolano and M. Jenkin  

E-Print Network (OSTI)

1 Underwater 3D SLAM through Entropy Minimization J.M. Sáez, A. Hogue, F. Escolano and M. Jenkin Underwater 3D SLAM through Entropy Minimization J.M. Sáez*, A. Hogue**, F. Escolano* and M. Jenkin** Underwater 3D SLAM through Entropy Minimization *Robot Vision Group, Dept. de Ciencia de la Computación e

Escolano, Francisco

374

Underwater vehicles: a surprising non time-optimal path This paper deals with the time-optimal problem for  

E-Print Network (OSTI)

Underwater vehicles: a surprising non time-optimal path M. Chyba Abstract This paper deals with the time-optimal problem for a class of underwater vehicles. We prove that if two configurations at rest or an underwater ve- hicle. This problem is a particularly challenging one and has been widely studied during

Sontag, Eduardo

375

3D Underwater Sensor Network Localization Amin Y. Teymorian, Student Member, IEEE, Wei Cheng, Student Member, IEEE,  

E-Print Network (OSTI)

3D Underwater Sensor Network Localization Amin Y. Teymorian, Student Member, IEEE, Wei Cheng, and Zexin Lu, Member, IEEE Abstract--We transform the 3D underwater sensor network (USN) localization termed as Underwater Sensor Positioning (USP). Through extensive simulations, we show that USP has

Cheng, Xiuzhen "Susan"

376

Underwater Maintenance Guide: Revision 2: A Guide to Diving and Remotely-Operated Vehicle Operations for Nuclear Maintenance Personnel  

Science Conference Proceedings (OSTI)

The use of water in nuclear power generating stations, both as an effective radiation barrier and thermal transfer medium, is critical to basic station operations. Consequently, underwater services play an important role in the maintenance and repair of these stations. Revision 2 of this guide expands previous discussions on underwater maintenance and provides new information on underwater welding and cutting operations and tasks.

1994-05-02T23:59:59.000Z

377

ATA: adaptive transmission algorithms for prolonging lifetime in underwater sensor networks  

Science Conference Proceedings (OSTI)

The severe energy constraints of sensors and the unique characteristics of underwater sensor networks (UWSNs) present major challenges for the long-term monitoring applications. This paper proposes two novel adaptive transmission algorithms for UWSNs ... Keywords: algorithms, lifetime, underwater sensor networks

Zhongwen Guo; Jinfeng Dou; Wei Han; Guangxu Zhang; Zhengang Ha

2008-05-01T23:59:59.000Z

378

Robust servo-control for underwater robots using banks of visual filters  

Science Conference Proceedings (OSTI)

We present an application of machine learning to the semi-automatic synthesis of robust servo-trackers for underwater robotics. In particular, we investigate an approach based on the use of Boosting for robust visual tracking of color objects in an underwater ...

Junaed Sattar; Gregory Dudek

2009-05-01T23:59:59.000Z

379

Building Energy Software Tools Directory: Acoustics Program  

NLE Websites -- All DOE Office Websites (Extended Search)

Acoustics Program Developed to help designers accurately model the sound level reaching building tenant's ears, the Trane Acoustics Program (TAP) "projects" equipment sound power...

380

The electron geodesic acoustic mode  

Science Conference Proceedings (OSTI)

In this report, a novel new mode, named the electron geodesic acoustic mode, is presented. This mode can occur in toroidal plasmas like the conventional geodesic acoustic mode (GAM). The frequency of this new mode is much larger than that of the conventional GAM by a factor equal to the square root of the ion to electron mass ratio.

Chakrabarti, N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064 (India); Guzdar, P. N. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Kaw, P. K. [Institute for Plasma Research Bhat, Gandhinagar 382428 (India)

2012-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Acoustics sound systems for baseball  

Science Conference Proceedings (OSTI)

Acoustic considerations impact the design of sound systems for baseball stadiums in several important ways. Intrusion by the sound system into adjacent residential communities must often be minimized. Excess attenuation greatly increases the required high frequency component of acoustic power for sound travelling long distances

2001-01-01T23:59:59.000Z

382

Search for acoustic signals from ultrahigh energy neutrinos in 1500 km{sup 3} of sea water  

SciTech Connect

An underwater acoustic sensor array spanning {approx}1500 km{sup 3} is used to search for cosmic-ray neutrinos of ultrahigh energies ( E{sub {nu}>}10{sup 18} eV). Approximately 328 million triggers accumulated over an integrated 130 days of data taking are analyzed. The sensitivity of the experiment is determined from a Monte Carlo simulation of the array using recorded noise conditions and expected waveforms. Two events are found to have properties compatible with showers in the energy range 10{sup 24} eVacoustic technique.

Kurahashi, Naoko; Gratta, Giorgio [Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305 (United States); Vandenbroucke, Justin [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics (United States) and SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305 (United States)

2010-10-01T23:59:59.000Z

383

Laser-Induced Underwater Plasma And Its Spectroscopic Applications  

SciTech Connect

Applications of Laser Induced Breakdown Spectroscopy (LIBS) for analysis of immersed solid and soft materials, and for liquid impurities are described. A method for improving the LIBS signal underwater and for obtaining quantitative analyses in presence of strong shot-to-shot variations of the plasma properties is proposed. Dynamic of the gas bubble formed by the laser pulse is also discussed, together with its importance in Double-Pulse (DP) laser excitation. Results of the studies relative to an application of multi-pulse sequence and its effects on the plasma and gas bubble formation are also presented.

Lazic, Violeta [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (Italy)

2008-09-23T23:59:59.000Z

384

Towards Localization and Mapping of Autonomous Underwater Vehicles: A Survey  

E-Print Network (OSTI)

Autonomous Underwater Vehicles (AUVs) have been used for a huge number of tasks ranging from commercial, military and research areas etc, while the fundamental function of a successful AUV is its localization and mapping ability. This report aims to review the relevant elements of localization and mapping for AUVs. First, a brief introduction of the concept and the historical development of AUVs is given; then a relatively detailed description of the sensor system used for AUV navigation is provided. As the main part of the report, a comprehensive investigation of the simultaneous localization and mapping (SLAM) for AUVs are conducted, including its application examples. Finally a brief conclusion

Ling Chen; Huosheng Hu

2011-01-01T23:59:59.000Z

385

Results of the first two seasons of underwater surveys at Episkopi Bay and Akrotiri, Cyprus  

E-Print Network (OSTI)

During the summers of 2003 and 2004, a small team of graduate students initiated an underwater archaeological survey off the coast of Cyprus as part of the University of Cincinnati excavations at Episkopi-Bamboula. With the support of the Institute of Nautical Archaeology (INA) at Texas A&M University and RPM Nautical Foundation, the project explored the seabed south and west of the Akrotiri Peninsula at Episkopi Bay. The overall aim of this ongoing diachronic survey is to determine the extent and nature of maritime contacts at Episkopi-Bamboula and its Greco-Roman successor, Kourion, from the Bronze Age through the Byzantine period. Efforts during these first two seasons concentrated on simple visual inspection of several promising areas near dangerous cliffs, offshore rocks and shallow reefs, as well as potential harbors and anchorages. The team recorded substantial pottery and anchor assemblages at Dreamer?s Bay, Cape Zevgari, and Avdimou Bay, including at least three shipwreck sites. Throughout the area, amphoras and anchors attest to varying levels of maritime activity over the past three millennia.The underwater material record reveals a modest level of Classical trade, followed by a respectable increase during the Hellenistic era. While very little material thus far can be attributed to the earlier Imperial centuries, the greatest quantities in terms of both individual sherds and coherent assemblages speaks strongly to intense trade during the Late Roman (Early Byzantine) period, from the fourth through the seventh century. Not surprisingly, this rapid floruit in maritime trade parallels the expansion of settlement throughout the island, including its eventual collapse in the middle of the seventh century.

Leidwanger, Justin Ryan

2005-12-01T23:59:59.000Z

386

Opto-acoustic thrombolysis  

DOE Patents (OSTI)

This invention is a catheter-based device for generating an ultrasound excitation in biological tissue. Pulsed laser light is guided through an optical fiber to provide the energy for producing the acoustic vibrations. The optical energy is deposited in a water-based absorbing fluid, e.g. saline, thrombolytic agent, blood or thrombus, and generates an acoustic impulse in the fluid through thermoelastic and/or thermodynamic mechanisms. By pulsing the laser at a repetition rate (which may vary from 10 Hz to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus or treating vasospasm. The catheter can also incorporate thrombolytic drug treatments as an adjunct therapy and it can be operated in conjunction with ultrasonic detection equipment for imaging and feedback control and with optical sensors for characterization of thrombus type and consistency.

Celliers, Peter (Berkeley, CA); Da Silva, Luiz (Danville, CA); Glinsky, Michael (Livermore, CA); London, Richard (Orinda, CA); Maitland, Duncan (Livermore, CA); Matthews, Dennis (Moss Beach, CA); Fitch, Pat (Livermore, CA)

2000-01-01T23:59:59.000Z

387

Opto-acoustic thrombolysis  

Science Conference Proceedings (OSTI)

This invention is a catheter-based device for generating an ultrasound excitation in biological tissue. Pulsed laser light is guided through an optical fiber to provide the energy for producing the acoustic vibrations. The optical energy is deposited in a water-based absorbing fluid, e.g. saline, thrombolytic agent, blood or thrombus, and generates an acoustic impulse in the fluid through thermoelastic and/or thermodynamic mechanisms. By pulsing the laser at a repetition rate (which may vary from 10 Hz to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus or treating vasospasm. The catheter can also incorporate thrombolytic drug treatments as an adjunct therapy and it can be operated in conjunction with ultrasonic detection equipment for imaging and feedback control and with optical sensors for characterization of thrombus type and consistency.

Celliers, P.; Silva, L. Da; Glinsky, M.; London, R.; Maitland, D.; Matthews, D.; Fitch, P.

2000-02-08T23:59:59.000Z

388

Acoustic Inspection Devices: Detecting the Undetectable  

Acoustic Inspection Devices: Detecting the Undetectable Emerging homeland security threats and increasingly sophisticated adversaries have heightened ...

389

Impacts of Bottom Trawling on Underwater Cultural Heritage  

E-Print Network (OSTI)

The fishing method of trawling, or dragging, has long been shown to be harmful to a plethora of sea life inhabiting the world?s oceans and inland waterways. Fishing nets scour the seabed, disturbing everything in their path, while usually in search of only one type of bottom-dwelling species. Impacts to the seafloor include a removal of topographic features, disturbance of the upper sediment layers, including deep furrows, as well as physical and chemical changes to sediment morphology. While biological organisms and communities can potentially recover from this destruction, archaeological data cannot. Fishermen have been raising important artifacts in their nets for over a century. These finds have helped archaeologists locate significant sites, but they also have the adverse effect of irreparably damaging these sites. This thesis explores the impacts of bottom trawling on underwater cultural heritage. The methods and gear used by trawlers and their documented effects upon the sea floor are identified. Examples of the types of damage shipwreck sites receive after being impacted by trawling are presented. Instances where fishermen have raised prehistoric artifacts from inundated land sites are also introduced. The fishing and archaeological communities must cooperate to limit further damage to underwater cultural heritage around the globe.

Atkinson, Christopher

2012-05-01T23:59:59.000Z

390

Coordination of an underwater glider fleet for adaptive sampling  

E-Print Network (OSTI)

Prediction (ASAP) projects aim to develop a sustainable, portable, adaptive ocean observing and prediction system for use in coastal environments. These projects employ, among other observation platforms, autonomous underwater vehicles that carry sensors to measure physical and biological signals in the ocean. The measurements from all sensing platforms are assimilated in real-time into advanced ocean models. The objective is to coordinate the mobile assets in order to collect data of highest possible utility. Critical to this effort are reliable, efficient and adaptive control strategies to enable the mobile sensor platforms to collect data autonomously. In this paper, we summarize feedback control strategies that enable us to gather useful information over a wide spectrum of spatial and temporal scales. First, we design formation control strategies useful for sampling small spatial scale processes (less than 5 km). In this framework, the feedback control laws maintain a desired formation of vehicles and allow the group to locate interesting features in the ocean. Some of these control strategies were implemented on a group of underwater gliders in Monterey Bay in August 2003, as part of the AOSN-II project. Second, we direct mobile sensor networks to provide synoptic coverage to investigate

Pradeep Bhatta; Edward Fiorelli; Francois Lekien; Naomi E. Leonard; Derek A. Paley; Fumin Zhang; Ralf Bachmayer; Russ E. Davis; David M. Fratantoni; Rodolphe Sepulchre

2005-01-01T23:59:59.000Z

391

Atmospheric Muon Flux at Sea Level, Underground, and Underwater  

E-Print Network (OSTI)

The vertical sea-level muon spectrum at energies above 1 GeV and the underground/underwater muon intensities at depths up to 18 km w.e. are calculated. The results are particularly collated with a great body of the ground-level, underground, and underwater muon data. In the hadron-cascade calculations, the growth with energy of inelastic cross sections and pion, kaon, and nucleon generation in pion-nucleus collisions are taken into account. For evaluating the prompt muon contribution to the muon flux, we apply two phenomenological approaches to the charm production problem: the recombination quark-parton model and the quark-gluon string model. To solve the muon transport equation at large depths of homogeneous medium, a semi-analytical method is used. The simple fitting formulas describing our numerical results are given. Our analysis shows that, at depths up to 6-7 km w. e., essentially all underground data on the muon intensity correlate with each other and with predicted depth-intensity relation for conventional muons to within 10%. However, the high-energy sea-level data as well as the data at large depths are contradictory and cannot be quantitatively decribed by a single nuclear-cascade model.

E. V. Bugaev; A. Misaki; V. A. Naumov; T. S. Sinegovskaya; S. I. Sinegovsky; N. Takahashi

1998-03-30T23:59:59.000Z

392

Acoustically Induced Streaming Flows near a Model Cod Otolith and their Potential Implications for Fish Hearing  

SciTech Connect

The ears of fishes are remarkable sensors for the small acoustic disturbances associated with underwater sound. For example, each ear of the Atlantic cod (Gadus morhua) has three dense bony bodies (otoliths) surrounded by fluid and tissue, and detects sounds at frequencies from 30 to 500 Hz. Atlantic cod have also been shown to localize sounds. However, how their ears perform these functions is not fully understood. Steady streaming, or time-independent, flows near a 350% scale model Atlantic cod otolith immersed in a viscous fluid were studied to determine if these fluid flows contain acoustically relevant information that could be detected by the ear s sensory hair cells. The otolith was oscillated sinusoidally at various orientations at frequencies of 8 24 Hz, corresponding to an actual frequency range of 280 830 Hz. Phaselocked particle pathline visualizations of the resulting flows give velocity, vorticity, and rate of strain fields over a single plane of this mainly two-dimensional flow. Although the streaming flows contain acoustically relevant information, the displacements due to these flows are likely too small to explain Atlantic cod hearing abilities near threshold. The results, however, may suggest a possible mechanism for detection of ultrasound in some fish species.

Kotas, Charlotte W [ORNL; Rogers, Peter [Georgia Institute of Technology; Yoda, Minami [Georgia Institute of Technology

2011-01-01T23:59:59.000Z

393

Acoustical heat-pumping engine  

DOE Patents (OSTI)

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1981-08-14T23:59:59.000Z

394

Acoustic Logs At Alum Area (Moos & Ronne, 2010) | Open Energy Information  

Open Energy Info (EERE)

Acoustic Logs At Alum Geothermal Area (Moos & Ronne, Acoustic Logs At Alum Geothermal Area (Moos & Ronne, 2010) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Acoustic Logs Activity Date Usefulness useful DOE-funding Unknown Notes The results revealed that acoustic images are superior to electrical images to detect structurally important natural fractures and stress-induced wellbore breakouts and tensile wall fractures, and were adequate to detect stratigraphic features. References Daniel Moos, Joel Ronne (2010) Selecting The Optimal Logging Suite For Geothermal Reservoir Evaluation- Results From The Alum 25-29 Well, Nevada Retrieved from "http://en.openei.org/w/index.php?title=Acoustic_Logs_At_Alum_Area_(Moos_%26_Ronne,_2010)&oldid=510215" Categories: Exploration Activities

395

Cross-Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) | Open Energy  

Open Energy Info (EERE)

Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Cross-Dipole Acoustic Log At Alum Geothermal Area (Moos & Ronne, 2010) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Cross-Dipole Acoustic Log Activity Date Usefulness useful DOE-funding Unknown Notes A crossed-dipole acoustic log detected stress induced anisotropy in the sediments, and also appeared to be able to identify and orient steeply dipping, compliant and therefore possibly conductive fractures in basement rocks. Because the shear-wave velocity was extremely low throughout most of the sedimentary section dipole data was required for its determination. The analysis results, which included a stress determination based on an

396

Acoustic Logs At Newberry Caldera Area (Combs, Et Al., 1999) | Open Energy  

Open Energy Info (EERE)

Acoustic Logs At Newberry Caldera Area (Combs, Et Al., 1999) Acoustic Logs At Newberry Caldera Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Acoustic Logs At Newberry Caldera Area (Combs, Et Al., 1999) Exploration Activity Details Location Newberry Caldera Area Exploration Technique Acoustic Logs Activity Date Usefulness could be useful with more improvements DOE-funding Unknown Notes The acoustic borehole televiewer (BHTV) was run twice in the wellbore with limited success. There were several problems with the tool's fimctions, but images were successfully obtained over the interval from 2748' to 3635'. References Jim Combs, John T. Finger, Colin Goranson, Charles E. Hockox Jr., Ronald D. Jacobsen, Gene Polik (1999) Slimhole Handbook- Procedures And Recommendations For Slimhole Drilling And Testing In Geothermal Exploration

397

Real-time classification via sparse representation in acoustic sensor networks  

Science Conference Proceedings (OSTI)

Acoustic Sensor Networks (ASNs) have a wide range of applications in natural and urban environment monitoring, as well as indoor activity monitoring. In-network classification is critically important in ASNs because wireless transmission costs several ... Keywords: ℓ1 minimization, acoustic sensor networks (ASNs), audio classification, sparse approximation

Bo Wei, Mingrui Yang, Yiran Shen, Rajib Rana, Chun Tung Chou, Wen Hu

2013-11-01T23:59:59.000Z

398

Employing the complete acoustical palette in teleconferencing design  

Science Conference Proceedings (OSTI)

The prevailing architectural acoustics approach in teleconferencing is “Deader is better” or “No acoustics is better than bad acoustics.” In some situations

Peter D'Antonio

1989-01-01T23:59:59.000Z

399

Acoustic Backscatter from Turbulent Microstructure  

Science Conference Proceedings (OSTI)

Acoustic backscatter has produced spectacular images of internal ocean processes for nearly two decades, but interpretation of the images remains ambiguous because several mechanisms can generate measurable backscatter. The authors present what ...

Harvey E. Seim; Michael C. Gregg; R. T. Miyamoto

1995-04-01T23:59:59.000Z

400

Forest Products: Acoustic Humidity Sensor  

SciTech Connect

The new acoustic sensor, designed as a humidity-control system for the paper and textile industries, can both eliminate overdrying and improve product quality by measuring humidity precisely. This new fact sheet explains how the process works.

Poole, L.; Recca, L.

1999-01-29T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Acoustically Enhanced Boiling Heat Transfer  

E-Print Network (OSTI)

An acoustic field is used to increase the critical heat flux (CHF) of a flat-boiling-heat-transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid-heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flatboiling surface for better study of an individual vapor bubble's reaction to the acoustic field. Work also includes application of the results from the single-bubble heater to a calibrated-copper heater used for quantifying the improvements in CHF.

Z. W. Douglas; M. K. Smith; A. Glezer

2008-01-07T23:59:59.000Z

402

Acoustic Characterization of Mesoscale Objects  

SciTech Connect

This report describes the science and engineering performed to provide state-of-the-art acoustic capabilities for nondestructively characterizing mesoscale (millimeter-sized) objects--allowing micrometer resolution over the objects entire volume. Materials and structures used in mesoscale objects necessitate the use of (1) GHz acoustic frequencies and (2) non-contacting laser generation and detection of acoustic waves. This effort demonstrated that acoustic methods at gigahertz frequencies have the necessary penetration depth and spatial resolution to effectively detect density discontinuities, gaps, and delaminations. A prototype laser-based ultrasonic system was designed and built. The system uses a micro-chip laser for excitation of broadband ultrasonic waves with frequency components reaching 1.0 GHz, and a path-stabilized Michelson interferometer for detection. The proof-of-concept for mesoscale characterization is demonstrated by imaging a micro-fabricated etched pattern in a 70 {micro}m thick silicon wafer.

Chinn, D; Huber, R; Chambers, D; Cole, G; Balogun, O; Spicer, J; Murray, T

2007-03-13T23:59:59.000Z

403

Acoustic Logs At Coso Geothermal Area (2005) | Open Energy Information  

Open Energy Info (EERE)

Coso Geothermal Area (2005) Coso Geothermal Area (2005) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Acoustic Logs Activity Date 2005 Usefulness not indicated DOE-funding Unknown Exploration Basis Well bore fracture analysis Notes Electrical and acoustic image logs have been collected from well 58A-10 in crystalline rock on the eastern margin. Electrical image logs appear to be sensitive to variations in mineralogy, porosity, and fluid content that highlight both natural fractures and rock fabrics. These fabric elements account for about 50% of the total population of planar structures seen in the electrical image log, but locally approach 100%. Acoustic image logs reveal a similar natural fracture population, but generally image slightly fewer fractures, and do not reveal rock fabric. Both logs also record

404

Verification of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle  

E-Print Network (OSTI)

mproving the performance of modular, low-cost autonomous underwater vehicles (AUVs) in such applications as long-range oceanographic survey, autonomous docking, and shallow-water mine countermeasures requires improving the ...

Prestero, Timothy (Timothy Jason), 1970-

2001-01-01T23:59:59.000Z

405

Development and validation of a conceptual design program for unmanned underwater vehicles  

E-Print Network (OSTI)

With a renewed focus on the Asia-Pacific region, the United States Navy will increasingly rely on high-endurance unmanned underwater vehicles (UUVs) to support successful operations in a challenging threat environment. ...

Laun, Alexander Walter, Ensign

2013-01-01T23:59:59.000Z

406

AMOUR V: A Hovering Energy Efficient Underwater Robot Capable of Dynamic Payloads  

Science Conference Proceedings (OSTI)

In this paper we describe the design and control algorithms of AMOUR, a low-cost autonomous underwater vehicle (AUV) capable of missions of marine survey and monitoring. AMOUR is a highly maneuverable robot capable of hovering and carrying ...

Iuliu Vasilescu; Carrick Detweiler; Marek Doniec; Daniel Gurdan; Stefan Sosnowski; Jan Stumpf; Daniela Rus

2010-04-01T23:59:59.000Z

407

Complete SE[superscript 3] underwater robot control with arbitrary thruster configurations  

E-Print Network (OSTI)

e present a control algorithm for autonomous underwater robots with modular thruster configuration. The algorithm can handle arbitrary thruster configurations. It maintains the robot's desired attitude while solving for ...

Doniec, Marek Wojciech

408

Rex 2 : design, construction, and operation of an unmanned underwater vehicle  

E-Print Network (OSTI)

The practical usage of unmanned underwater vehicles (UUVs) is limited by vehicle and operation cost, difficulty in accurate navigation, and communication between the vehicle and operator. The "Rex 2" UUV employs a system ...

Owens, Dylan

2009-01-01T23:59:59.000Z

409

Determining Turbulent Vertical Velocity, and Fluxes of Heat and Salt with an Autonomous Underwater Vehicle  

Science Conference Proceedings (OSTI)

The authors show that vertical turbulent fluxes in the upper ocean can be measured directly with an autonomous underwater vehicle (AUV). A horizontal profile of vertical water velocity is obtained by applying a Kalman smoother to AUV motion data. ...

Daniel R. Hayes; James H. Morison

2002-05-01T23:59:59.000Z

410

Dynamic response and maneuvering strategies of a hybrid autonomous underwater vehicle in hovering  

E-Print Network (OSTI)

The Odyssey IV autonomous underwater vehicle (AUV) is the next generation of unmanned subsurface robots from the MIT Sea Grant AUV Laboratory. The Odyssey IV AUV has a novel propulsion system, which includes a pair of ...

Cooney, Lauren Alise

2009-01-01T23:59:59.000Z

411

13.49 Maneuvering and Control of Surface and Underwater Vehicles, Fall 2000  

E-Print Network (OSTI)

Maneuvering motions of surface and underwater vehicles. Derivation of equations of motion, hydrodynamic coefficients. Memory effects. Linear and nonlinear forms of the equations of motion. Control surfaces modeling and ...

Triantafyllou, Michael S.

412

Determining Bottom Reflectance and Water Optical Properties Using Unmanned Underwater Vehicles under Clear or Cloudy Skies  

Science Conference Proceedings (OSTI)

An unmanned underwater vehicle (UUV) with hyperspectral optical sensors that measure downwelling irradiance and upwelling radiance was deployed over sandy bottoms, sea grass patches, and coral reefs near Lee Stocking Island, Bahamas, during the ...

David C. English; Kendall L. Carder

2006-02-01T23:59:59.000Z

413

Development of a New Underwater Bathymetric Laser Imaging System: L-Bath  

Science Conference Proceedings (OSTI)

The design, construction, and performance of a new high-resolution underwater bathymetric prototype system (L-Bath) with extended imaging capability is presented. The design offers simultaneous reflectance and depth information on a pixel-by-...

Karl D. Moore; Jules S. Jaffe; Benjamin L. Ochoa

2000-08-01T23:59:59.000Z

414

Remote Real-Time Video-Enabled Docking for Underwater Autonomous Platforms  

Science Conference Proceedings (OSTI)

One of the key challenges in the development and implementation of ocean observatories is sustained observations over relevant temporal and spatial scales. Autonomous underwater vehicles (AUVs) have demonstrated their potential for synoptic ...

Mark A. Moline; Oscar Schofield

2009-12-01T23:59:59.000Z

415

Development of a porous piezoresistive material and its applications to underwater pressure sensors and tactile sensors  

E-Print Network (OSTI)

MEMS (Microelectromechanical System) pressure sensor arrays are gaining attention in the field of underwater navigation because they are seen as alternatives to current sonar and vision-based systems that fail to navigate ...

Woo, Mun Ee

2013-01-01T23:59:59.000Z

416

A flexible underwater pressure sensor array for artificial lateral line applications  

E-Print Network (OSTI)

This thesis develops a flexible elastomer-based underwater pressure sensor array. When mounted onto the hull of an aquatic vehicle, the array enables obstacle detection, identification and tracking, and can help the vehicle ...

Yaul, Frank M

2011-01-01T23:59:59.000Z

417

Autonomous underwater data muling using wireless optical communication and agile AUV control  

E-Print Network (OSTI)

Underwater exploration and surveillance currently relies on subsea cables and tethers to relay data back to the user. The cause for this is that water heavily absorbs most electromagnetic signals, preventing effective radio ...

Doniec, Marek Wojciech

2013-01-01T23:59:59.000Z

418

Biomimetic oscillating foil propulsion to enhance underwater vehicle agility and maneuverability  

E-Print Network (OSTI)

Inspired by the swimming abilities of marine animals, this thesis presents "Finnegan the RoboTurtle", an autonomous underwater vehicle (AUV) powered entirely by four flapping foils. Biomimetic actuation is shown to produce ...

Licht, Stephen Carl

2008-01-01T23:59:59.000Z

419

Collection of Water Samples from an Autonomous Underwater Vehicle for Tracer Analysis  

Science Conference Proceedings (OSTI)

A compact water sampler rated to full ocean depth has been deployed from an autonomous underwater vehicle (AUV) to enable oceanographic tracer measurements. Techniques developed to allow the instrument to collect up to 49 samples of sufficient ...

Paul A. Dodd; Martin R. Price; Karen J. Heywood; Miles Pebody

2006-12-01T23:59:59.000Z

420

Aquatecture : underwater dwellings and sea born structures as paradigms of design  

E-Print Network (OSTI)

There are many reasons for undertaking a work such as this. Among them are the benefits offered to society when we acknowledge the potential of submersible structures, The provision of habitable underwater space remains ...

Guillermo, Ricardo

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Oil/gas collector/separator for underwater oil leaks  

DOE Patents (OSTI)

This invention is comprised of an oil/gas collector/separator for recovery of oil leaking, for example, from an offshore or underwater oil well. The separator is floated over the point of the leak and tethered in place so as to receive oil/gas floating, or forced under pressure, toward the water surface from either a broken or leaking oil well casing, line, or sunken ship. The separator is provided with a downwardly extending skirt to contain the oil/gas which floats or is forced upward into a dome wherein the gas is separated from the oil/water, with the gas being flared (burned) at the top of the dome, and the oil is separated from water and pumped to a point of use. Since the density of oil is less than that of water it can be easily separated from any water entering the dome.

Henning, C.D.

1992-12-31T23:59:59.000Z

422

Oil/gas collector/separator for underwater oil leaks  

DOE Patents (OSTI)

An oil/gas collector/separator for recovery of oil leaking, for example, from an offshore or underwater oil well. The separator is floated over the point of the leak and tethered in place so as to receive oil/gas floating, or forced under pressure, toward the water surface from either a broken or leaking oil well casing, line, or sunken ship. The separator is provided with a downwardly extending skirt to contain the oil/gas which floats or is forced upward into a dome wherein the gas is separated from the oil/water, with the gas being flared (burned) at the top of the dome, and the oil is separated from water and pumped to a point of use. Since the density of oil is less than that of water it can be easily separated from any water entering the dome.

Henning, Carl D. (Livermore, CA)

1993-01-01T23:59:59.000Z

423

SNG completes deepest underwater pipelay in Gulf of Mexico  

SciTech Connect

This paper reports that gas began flowing this spring in the deepest underwater, large-diameter pipeline in the U.S. Gulf of Mexico. Water depth along the route of the pipeline varies from approximately 460 ft at the Alabaster platform, increasing to the record depth of 1,220 ft in the Mississippi Canyon area, and decreasing to negligible water depth at the landfall site southwest of Venice. The SNG Mississippi Canyon Block 397 pipeline project exemplifies how a pipeline project can encounter an array of conditions which prompt special design considerations and installation techniques. Important considerations for this project were related to pipe properties, anti-corrosion and weight coatings, span and buckle considerations, and installation equipment. A team effort was used to study, research, test, design, and install this pipeline.

Vogt, G.B. (Project Consulting Services Inc., Metairie, LA (US))

1992-08-24T23:59:59.000Z

424

''Water bath'' effect during the electrical underwater wire explosion  

SciTech Connect

The results of a simulation of underwater electrical wire explosion at a current density >10{sup 9} A/cm{sup 2}, total discharge current of {approx}3 MA, and rise time of the current of {approx}100 ns are presented. The electrical wire explosion was simulated using a one-dimensional radiation-magnetohydrodynamic model. It is shown that the radiation of the exploded wire produces a thin conducting plasma shell in the water in the vicinity of the exploding wire surface. It was found that this plasma shell catches up to 30% of the discharge current. Nevertheless, it was shown that the pressure and temperature of the wire material remain unchanged as compared with the idealized case of the electrical wire explosion in vacuum. This result is explained by a 'water bath' effect.

Oreshkin, V. I.; Chaikovsky, S. A.; Ratakhin, N. A.; Grinenko, A.; Krasik, Ya. E. [High Current Electronic Institute SB RAS, Tomsk (Russian Federation); Physics Department, Technion, Haifa 32000 (Israel)

2007-10-15T23:59:59.000Z

425

Expected Muon Energy Spectra and Zenithal Distributions Deep Underwater  

E-Print Network (OSTI)

Energy spectra and zenith angle distributions of atmospheric muons are calculated for the depths of operation of large underwater neutrino telescopes. The estimation of the prompt muon contribution is performed with three approaches to charm hadroproduction: recombination quark-parton model, quark-gluon string model, and perturbative QCD based models. Calculations show that the larger are zenith angles and water thickness above the detector, the lower is the energy at which the prompt muon flux becomes equal to conventional one (``crossing energy'') . For instance, for the depth of the Baikal Neutrino Telescope and for zenith angle of 78 degrees the crossing energy is about 300 TeV, whereas it is only 8 TeV for the NESTOR depth. Nevertheless, the muon flux of the crossing energy at NESTOR depth is in order of magnitude lower in comparison with the Baikal depth.

A. Misaki; V. A. Naumov; T. S. Sinegovskaya; S. I. Sinegovsky; N. Takahashi

1999-05-19T23:59:59.000Z

426

Multi-Modal Local Sensing and Communication for Collective Underwater Systems  

E-Print Network (OSTI)

This paper is devoted to local sensing and communication for collective underwater systems used in networked and swarm modes. It is demonstrated that a specific combination of modal and sub-modal communication, used simultaneously for robot-robot and robot-object detection, can create a dedicated cooperation between multiple AUVs. These technologies, platforms and experiments are shortly described, and allow us to make a conclusion about useful combinations of different signaling approaches for collective underwater systems.

Kernbach, Serge; Sutantyo, Donny

2011-01-01T23:59:59.000Z

427

HIERARCHICAL HYBRID-MODEL BASED DESIGN, VERIFICATION, SIMULATION, AND SYNTHESIS OF MISSION CONTROL FOR AUTONOMOUS UNDERWATER VEHICLES.  

E-Print Network (OSTI)

??The objective of modeling, verification, and synthesis of hierarchical hybrid mission control for underwater vehicle is to (i) propose a hierarchical architecture for mission control… (more)

Bhattacharyya, Siddhartha

2005-01-01T23:59:59.000Z

428

Target tracking onboard an autonomous underwater vehicle: determining optimal towed array heading in an anisotropic noise field .  

E-Print Network (OSTI)

??In order to overcome the challenges that an anisotropic noise field poses for underwater target tracking, we conduct an onboard estimation of the horizontal noise… (more)

Parra-Orlandoni, Maria Alejandra.

2007-01-01T23:59:59.000Z

429

The Design of Acoustic Radar Baffles  

Science Conference Proceedings (OSTI)

Compact acoustic antenna arrays, commonly used for profiling urban atmospheres, usually require acoustic baffles to minimize reflections from hard objects and to limit the impact of the 2–6-kHz signals on inhabitants. To facilitate optimum ...

C. J. Werkhoven; S. G. Bradley

1997-06-01T23:59:59.000Z

430

Acoustic data transmission through a drill string  

DOE Patents (OSTI)

Acoustical signals are transmitted through a drill string by canceling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter impedance characteristics of the drill string. 5 figs.

Drumheller, D.S.

1988-04-21T23:59:59.000Z

431

Use of Underwater Gliders for Acoustic Data Retrieval from Subsurface Oceanographic Instrumentation and Bidirectional Communication in the Deep Ocean  

Science Conference Proceedings (OSTI)

Many fixed oceanographic instruments and observing systems are deployed in the water column or on the seafloor for extended periods of time without any expression at the sea surface. To routinely communicate with such subsurface instruments in the ...

Uwe Send; Lloyd Regier; Brent Jones

2013-05-01T23:59:59.000Z

432

Surface Measurements of Precipitation from an Ocean Mooring: The Underwater Acoustic Log from the South China Sea  

Science Conference Proceedings (OSTI)

Surface measurements of precipitation in oceanic environments have proven especially difficult to obtain because traditional technologies such as tipping-bucket rain gauges are unsuitable for deployment from oceanic platforms such as ships and ...

Jeffrey A. Nystuen; Michael J. McPhaden; H. Paul Freitag

2000-12-01T23:59:59.000Z

433

Particle analysis in an acoustic cytometer  

SciTech Connect

The present invention is a method and apparatus for acoustically manipulating one or more particles. Acoustically manipulated particles may be separated by size. The particles may be flowed in a flow stream and acoustic radiation pressure, which may be radial, may be applied to the flow stream. This application of acoustic radiation pressure may separate the particles. In one embodiment, the particles may be separated by size, and as a further example, the larger particles may be transported to a central axis.

Kaduchak, Gregory; Ward, Michael D

2012-09-18T23:59:59.000Z

434

Owens Corning Acoustic & Insulation Product Testing ...  

Science Conference Proceedings (OSTI)

... Insulation. [01/T10] ASTM C687 Thermal Resistance of Loose-Fill Building Insulation. Acoustical Testing Services. Accreditation ...

2014-01-03T23:59:59.000Z

435

Acoustic Analysis of Adult Speaker Age  

Science Conference Proceedings (OSTI)

Information about the age of the speaker is always present in speech. It is used as perceptual cues to age by human listeners, and can be measured acoustically and used by automatic age estimators. This chapter offers an introduction to the phonetic ... Keywords: Acoustic analysis, Acoustic correlates, Phonetics, Speaker age

Susanne Schötz

2007-02-01T23:59:59.000Z

436

Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound  

SciTech Connect

Hydrokinetic turbines will be a source of noise in the marine environment - both during operation and during installation/removal. High intensity sound can cause injury or behavioral changes in marine mammals and may also affect fish and invertebrates. These noise effects are, however, highly dependent on the individual marine animals; the intensity, frequency, and duration of the sound; and context in which the sound is received. In other words, production of sound is a necessary, but not sufficient, condition for an environmental impact. At a workshop on the environmental effects of tidal energy development, experts identified sound produced by turbines as an area of potentially significant impact, but also high uncertainty. The overall objectives of this project are to improve our understanding of the potential acoustic effects of tidal turbines by: (1) Characterizing sources of existing underwater noise; (2) Assessing the effectiveness of monitoring technologies to characterize underwater noise and marine mammal responsiveness to noise; (3) Evaluating the sound profile of an operating tidal turbine; and (4) Studying the effect of turbine sound on surrogate species in a laboratory environment. This study focuses on a specific case study for tidal energy development in Admiralty Inlet, Puget Sound, Washington (USA), but the methodologies and results are applicable to other turbine technologies and geographic locations. The project succeeded in achieving the above objectives and, in doing so, substantially contributed to the body of knowledge around the acoustic effects of tidal energy development in several ways: (1) Through collection of data from Admiralty Inlet, established the sources of sound generated by strong currents (mobilizations of sediment and gravel) and determined that low-frequency sound recorded during periods of strong currents is non-propagating pseudo-sound. This helped to advance the debate within the marine and hydrokinetics acoustic community as to whether strong currents produce propagating sound. (2) Analyzed data collected from a tidal turbine operating at the European Marine Energy Center to develop a profile of turbine sound and developed a framework to evaluate the acoustic effects of deploying similar devices in other locations. This framework has been applied to Public Utility District No. 1 of Snohomish Country's demonstration project in Admiralty Inlet to inform postinstallation acoustic and marine mammal monitoring plans. (3) Demonstrated passive acoustic techniques to characterize the ambient noise environment at tidal energy sites (fixed, long-term observations recommended) and characterize the sound from anthropogenic sources (drifting, short-term observations recommended). (4) Demonstrated the utility and limitations of instrumentation, including bottom mounted instrumentation packages, infrared cameras, and vessel monitoring systems. In doing so, also demonstrated how this type of comprehensive information is needed to interpret observations from each instrument (e.g., hydrophone data can be combined with vessel tracking data to evaluate the contribution of vessel sound to ambient noise). (5) Conducted a study that suggests harbor porpoise in Admiralty Inlet may be habituated to high levels of ambient noise due to omnipresent vessel traffic. The inability to detect behavioral changes associated with a high intensity source of opportunity (passenger ferry) has informed the approach for post-installation marine mammal monitoring. (6) Conducted laboratory exposure experiments of juvenile Chinook salmon and showed that exposure to a worse than worst case acoustic dose of turbine sound does not result in changes to hearing thresholds or biologically significant tissue damage. Collectively, this means that Chinook salmon may be at a relatively low risk of injury from sound produced by tidal turbines located in or near their migration path. In achieving these accomplishments, the project has significantly advanced the District's goals of developing a demonstration-scale tidal energy proj

Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

2012-03-30T23:59:59.000Z

437

Acoustic black holes Matt Visser  

E-Print Network (OSTI)

Acoustic black holes Matt Visser Physics Department Washington University Saint Louis USA Ole Miss you develop a number of use- ful connections between supersonic uid ow and black holes in general is the basis underlying a deep and fruitful analogy between the black holes of Einstein gravity and supersonic

Visser, Matt

438

http://www.digitalocean.eu : FP7 262160 (2010-2012) Human-Robot-Interfaces based on Mixed Reality for Underwater Robot  

E-Print Network (OSTI)

for Underwater Robot Teleoperation Christophe Domingues*, Mouna Essabbah*, Nader Cheaib* and Samir Otmane* Alain two Human-Robot interfaces for underwater robot teleoperation. This work is in the context of the Digital Ocean Europe project1 that aims at digitalizing seafloor sites in 3D imagery using underwater

Paris-Sud XI, Université de

439

A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater Surveys  

E-Print Network (OSTI)

A Single-armed Manta-board as a New Diver-controlled Planing Board and Its Use for Underwater, Australia. Abstract-Due to inadequacies ofprevi ous underwater towing techniques and the special needs of a recent underwater sur vey, a modified mania-board technique was developed. With this new technique

440

Boussinesq modeling of surface waves due to underwater landslides  

E-Print Network (OSTI)

Consideration is given to the influence of an underwater landslide on waves at the surface of a shallow body of fluid. The equations of motion which govern the evolution of the barycenter of the landslide mass include various dissipative effects due to bottom friction, internal energy dissipation, and viscous drag. The surface waves are studied in the Boussinesq scaling, with time-dependent bathymetry. A numerical model for the Boussinesq equations is introduced which is able to handle time-dependent bottom topography, and the equations of motion for the landslide and surface waves are solved simultaneously. The numerical solver for the Boussinesq equations can also be restricted to implement a shallow-water solver, and the shallow-water and Boussinesq configurations are compared. A particular bathymetry is chosen to illustrate the general method, and it is found that the Boussinesq system predicts larger wave run-up than the shallow-water theory in the example treated in this paper. It also found that the fi...

Dutykh, Denys

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Polarimetry and Schlieren diagnostics of underwater exploding wires  

SciTech Connect

Nondisturbing laser-probing polarimetry (based on the Faraday and Kerr effects) and Schlieren diagnostics were used in the investigation of underwater electrical wire explosion. Measuring the polarization plane rotation angle of a probing laser beam due to the Faraday effect allows one to determine an axially resolved current flowing through the exploding wire, unlike commonly used current probes. This optical method of measuring current yields results that match those obtained using a current viewing resistor within an accuracy of 10%. The same optical setup allows simultaneous space-resolved measurement of the electric field using the Kerr effect. It was shown that the maximal amplitude of the electric field in the vicinity of the high-voltage electrode is approx80 kV/cm and that the radial electric field is <1 MV/cm during the wire explosion. Finally, it was shown that the use of Schlieren diagnostics allows one to obtain qualitatively the density distribution behind the shock wave front, which is important for the determination of the energy transfer from the discharge channel to the generated water flow.

Fedotov-Gefen, A. V.; Krasik, Ya. E. [Physics Department, Technion, 32000 Haifa (Israel)

2009-11-01T23:59:59.000Z

442

Wideband Source Localization Using a Distributed Acoustic Vector-Sensor Array  

E-Print Network (OSTI)

Abstract—We derive fast wideband algorithms, based on measurements of the acoustic intensity, for determining the bearings of a target using an acoustic vector sensor (AVS) situated in free space or on a reflecting boundary. We also obtain a lower bound on the mean-square angular error (MSAE) of such estimates. We then develop general closed-form weighted least-squares (WLS) and reweighted least-squares algorithms that compute the three-dimensional (3-D) location of a target whose bearing to a number of dispersed locations has been measured. We devise a scheme for adaptively choosing the weights for the WLS routine when measures of accuracy for the bearing estimates, such as the lower bound on the MSAE, are available. In addition, a measure of the potential estimation accuracy of a distributed system is developed based on a two-stage application of the Cramér–Rao bound. These 3-D results are quite independent of how bearing estimates are obtained. Naturally, the two parts of the paper are tied together by examining how well distributed arrays of AVSs located on the ground, seabed, and in free space can determine the 3-D position of a target The results are relevant to the localization of underwater and airborne sources using freely drifting, moored, or ground sensors. Numerical simulations illustrate the effectiveness of our estimators and the new potential performance measure. I.

Malcolm Hawkes; Arye Nehorai

2003-01-01T23:59:59.000Z

443

Opto-acoustic transducer for medical applications  

DOE Patents (OSTI)

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

Benett, William (Livermore, CA); Celliers, Peter (Berkeley, CA); Da Silva, Luiz (Danville, CA); Glinsky, Michael (Livermore, CA); London, Richard (Orinda, CA); Maitland, Duncan (Livermore, CA); Matthews, Dennis (Moss Beach, CA); Krulevich, Peter (Pleasanton, CA); Lee, Abraham (Walnut Creek, CA)

1999-01-01T23:59:59.000Z

444

Opto-acoustic transducer for medical applications  

DOE Patents (OSTI)

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

Benett, William (Livermore, CA); Celliers, Peter (Berkeley, CA); Da Silva, Luiz (Danville, CA); Glinsky, Michael (Livermore, CA); London, Richard (Orinda, CA); Maitland, Duncan (Livermore, CA); Matthews, Dennis (Moss Beach, CA); Krulevich, Peter (Pleasanton, CA); Lee, Abraham (Walnut Creek, CA)

2002-01-01T23:59:59.000Z

445

Opto-acoustic transducer for medical applications  

Science Conference Proceedings (OSTI)

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control. 7 figs.

Benett, W.; Celliers, P.; Da Silva, L.; Glinsky, M.; London, R.; Maitland, D.; Matthews, D.; Krulevich, P.; Lee, A.

1999-08-31T23:59:59.000Z

446

Review Article Underwater Image Processing: State of the Art of Restoration and Image Enhancement Methods  

E-Print Network (OSTI)

License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The underwater image processing area has received considerable attention within the last decades, showing important achievements. In this paper we review some of the most recent methods that have been specifically developed for the underwater environment. These techniques are capable of extending the range of underwater imaging, improving image contrast and resolution. After considering the basic physics of the light propagation in the water medium, we focus on the different algorithms available in the literature. The conditions for which each of them have been originally developed are highlighted as well as the quality assessment methods used to evaluate their performance. 1.

Raimondo Schettini; Silvia Corchs

2010-01-01T23:59:59.000Z

447

Analysis of particle penetration into aluminum plate using underwater shock wave  

Science Conference Proceedings (OSTI)

Some techniques using underwater shock waves have been developed for several material processing applications: explosive welding, shock compaction, and shock synthesis. In this research, a new technique was developed for surface modification of an aluminum plate. Diamond particles were accelerated by an underwater shock wave and penetrated into an aluminum plate, creating a surface coating of diamond on the aluminum plate. In the observation of the cross-section of the recovered Al-diamond composite, a rich diamond layer was confirmed at about 200 {mu}m depth. XRD and wear measurements were conducted for the recovered Al-diamond composite. We also report on the optical observation of the underwater shock wave in this paper.

Tanaka, S. [Faculty of engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto City, Kumamoto 860-8555 (Japan); Hokamoto, K.; Itoh, S. [Shock Wave and Condensed Matter Research Center, Kumamoto University, 2-39-1 Kurokami, Kumamoto City, Kumamoto 860-8555 (Japan)

2007-12-12T23:59:59.000Z

448

Acoustic Emission Monitoring of the Syracuse Athena Temple: Scale Invariance in the Timing of Ruptures  

Science Conference Proceedings (OSTI)

We perform a comparative statistical analysis between the acoustic-emission time series from the ancient Greek Athena temple in Syracuse and the sequence of nearby earthquakes. We find an apparent association between acoustic-emission bursts and the earthquake occurrence. The waiting-time distributions for acoustic-emission and earthquake time series are described by a unique scaling law indicating self-similarity over a wide range of magnitude scales. This evidence suggests a correlation between the aging process of the temple and the local seismic activity.

Niccolini, G.; Carpinteri, A.; Lacidogna, G.; Manuello, A. [Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino (Italy)] [Department of Structural Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

2011-03-11T23:59:59.000Z

449

Quantum entanglement for acoustic spintronics  

SciTech Connect

We consider the entanglement of spins for two electrons contributing to the acoustoelectric current driven by a surface acoustic wave (SAW) in two adjacent narrow channels by calculating their exchange energy (J). The channels belong to an acoustic nanocircuit which comprises a network of quasi-one-dimensional pinched-off channels serving as wires along which SAW quantum dots transport electrons. This is motivated by possible practical applications involving quantum information processing and quantum computers. We calculate J as a function of time as the electrons travel side-by-side in the adjacent channels and as a function of the distance between the centers of the channels. The leakage from the state in which the system is prepared, is calculated. The oscillations in the leakage indicate the probability for the electron system to make transitions between the ground and excited states, or for an electron to hop back and forth between channels.

Gumbs, Godfrey; Abranyos, Yonatan [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10021 (United States)

2004-11-01T23:59:59.000Z

450

Acoustic horizons in nuclear fluids  

E-Print Network (OSTI)

We consider a hydrodynamic description of the spherically symmetric outward flow of nuclear matter, accommodating dispersion in it as a very weak effect. About the resulting stationary conditions in the flow, we apply an Eulerian scheme to derive a fully nonlinear equation of a time-dependent radial perturbation. In its linearized limit, with no dispersion, this equation implies the static acoustic horizon of an analogue gravity model. We, however, show that time-dependent nonlinear effects destabilize the static horizon. We also model the perturbation as a high-frequency travelling wave, and perform a {\\it WKB} analysis, in which the effect of weak dispersion is studied iteratively. We show that even arbitrarily small values of dispersion make the horizon fully opaque to any acoustic disturbance propagating against the bulk flow, with the amplitude and the energy flux of the radial perturbation undergoing a discontinuity at the horizon, and decaying exponentially just outside it.

Niladri Sarkar; Abhik Basu; Jayanta K. Bhattacharjee; Arnab K. Ray

2013-06-03T23:59:59.000Z

451

Cylindrical acoustic levitator/concentrator  

DOE Patents (OSTI)

A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

Kaduchak, Gregory (Los Alamos, NM); Sinha, Dipen N. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

452

Solid Rocket Motor Acoustic Testing  

DOE Green Energy (OSTI)

Acoustic data are often required for the determination of launch and powered flight loads for rocket systems and payloads. Such data are usually acquired during test firings of the solid rocket motors. In the current work, these data were obtained for two tests at a remote test facility where we were visitors. This paper describes the data acquisition and the requirements for working at a remote site, interfacing with the test hosts.

Rogers, J.D.

1999-03-31T23:59:59.000Z

453

Alion Science and Technology / Riverbank Acoustical ...  

Science Conference Proceedings (OSTI)

... E2179 Laboratory Measurement of the Effectiveness of Floor Coverings in Reducing ... 08/P61] AAMA 1801 Acoustical Rating of Windows, Doors and ...

2013-07-19T23:59:59.000Z

454

Wind Turbine Acoustic Noise A white paper  

E-Print Network (OSTI)

Wind Turbine Acoustic Noise A white paper Prepared by the Renewable Energy Research Laboratory...................................................................... 8 Sound from Wind Turbines .............................................................................................. 10 Sources of Wind Turbine Sound

Massachusetts at Amherst, University of

455

DEVELOPMENT OF A LONG WAVELENGTH ACOUSTIC ...  

Science Conference Proceedings (OSTI)

... are developing a long-wavelength acoustic flowmeter (LWAF) for accurate, economical measurements of exhaust flows from coal-burning power ...

456

Ricoh Company LTD. Acoustical Testing Laboratory  

Science Conference Proceedings (OSTI)

Acoustical Testing Laboratory. ... 143-8555 JAPAN Contact: Mr. Seiji Nakamura Phone: 81-046-292-3871 Fax: E-Mail: seiji.nakamura@nts.ricoh.co.jp ...

2013-11-08T23:59:59.000Z

457

THE EFFECT OF ACOUSTIC MODULATION ON SPRAY ...  

Science Conference Proceedings (OSTI)

... that at full load in liquid injection systems, extra energy or perturbation is ... The acoustic modulation is generated by a piezoelectric crystal driven by a ...

458

Acoustic concentration of particles in fluid flow  

DOE Patents (OSTI)

An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)

2010-11-23T23:59:59.000Z

459

Acoustic Logs At Raft River Geothermal Area (1979) | Open Energy  

Open Energy Info (EERE)

Raft River Geothermal Area (1979) Raft River Geothermal Area (1979) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Acoustic Logs Activity Date 1979 Usefulness useful DOE-funding Unknown Exploration Basis To permit the lateral and vertical extrapolation of core and test data and bridged the gap between surface geophysical data and core analyses. Notes Televiewer logs permitted the location and orientation of numerous fractures and several features that may be faults. References Keys, W. S.; Sullivan, J. K. (1 June 1979) Role of borehole geophysics in defining the physical characteristics of the Raft River geothermal reservoir, Idaho Retrieved from "http://en.openei.org/w/index.php?title=Acoustic_Logs_At_Raft_River_Geothermal_Area_(1979)&oldid=473816"

460

Depth control of remotely operated underwater vehicles using an adaptive fuzzy sliding mode controller  

Science Conference Proceedings (OSTI)

Sliding mode control, due to its robustness against modelling imprecisions and external disturbances, has been successfully employed to the dynamic positioning of remotely operated underwater vehicles. In order to improve the performance of the complete ... Keywords: Adaptive algorithms, Depth control, Fuzzy logic, Nonlinear control, Remotely operated vehicles, Sliding modes

Wallace M. Bessa; Max S. Dutra; Edwin Kreuzer

2008-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

An adaptive fuzzy sliding mode controller for remotely operated underwater vehicles  

Science Conference Proceedings (OSTI)

Sliding mode control is a very attractive control scheme because of its robustness against both structured and unstructured uncertainties as well as external disturbances. In this way, it has been widely employed for the dynamic positioning of remotely ... Keywords: Adaptive algorithms, Dynamic positioning, Fuzzy logic, Remotely operated underwater vehicles, Sliding modes

Wallace M. Bessa; Max S. Dutra; Edwin Kreuzer

2010-01-01T23:59:59.000Z

462

A Behavioral Probabilistic Risk Assessment Framework for Managing Autonomous Underwater Vehicle Deployments  

Science Conference Proceedings (OSTI)

The deployment of a deep-diving long-range autonomous underwater vehicle (AUV) is a complex operation that requires the use of a risk-informed decision-making process. Operational risk assessment is heavily dependent on expert subjective judgment. ...

Mario Brito; Gwyn Griffiths; James Ferguson; David Hopkin; Richard Mills; Richard Pederson; Erin MacNeil

2012-11-01T23:59:59.000Z

463

An Evaluation of the WOTAN Technique of Inferring Oceanic Winds from Underwater Ambient Sound  

Science Conference Proceedings (OSTI)

The potential of the WOTAN technique to estimate oceanic winds from underwater ambient sound is thoroughly evaluated. Anemometer winds and sound spectrum levels at 11 frequencies in the range 3–25 kHz from the FASINEX Experiment are used to ...

Svein Vagle; William G. Large; David M. Farmer

1990-08-01T23:59:59.000Z

464

Remote robotic underwater grinding system and modeling for rectification of hydroelectric structures  

Science Conference Proceedings (OSTI)

A submersible grinding robot has been designed to automate the dam gate metallic structure repair process. In order to measure and control the amount of material removed during the process, an empirical approach for modeling the material removal rate ... Keywords: Air injector, Grinding modeling, Material removal rate (MRR), Robotic grinding, Underwater grinding process, Water drag effect

Dominique Thuot; Zhaoheng Liu; Henri Champliaud; Julien Beaudry; Pierre-Luc Richard; Michel Blain

2013-02-01T23:59:59.000Z

465

Surface acoustic wave probe implant for predicting epileptic seizures  

DOE Patents (OSTI)

A system and method for predicting and avoiding a seizure in a patient. The system and method includes use of an implanted surface acoustic wave probe and coupled RF antenna to monitor temperature of the patient's brain, critical changes in the temperature characteristic of a precursor to the seizure. The system can activate an implanted cooling unit which can avoid or minimize a seizure in the patient.

Gopalsami, Nachappa (Naperville, IL); Kulikov, Stanislav (Sarov, RU); Osorio, Ivan (Leawood, KS); Raptis, Apostolos C. (Downers Grove, IL)

2012-04-24T23:59:59.000Z

466

Acoustic emission monitoring for assessment of steel bridge details  

SciTech Connect

Acoustic emission (AE) testing was deployed on details of two large steel Interstate Highway bridges: one cantilever through-truss and one trapezoidal box girder bridge. Quantitative measurements of activity levels at known and suspected crack locations were made by monitoring AE under normal service loads (e.g., live traffic and wind). AE indications were used to direct application of radiography, resulting in identification of a previously unknown flaw, and to inform selection of a retrofit detail.

Kosnik, D. E.; Corr, D. J. [Infrastructure Technology Institute, Northwestern University, Evanston, IL 60208 (United States); Hopwood, T. [Kentucky Transportation Center, University of Kentucky, Lexington, KY 40506 (United States)

2011-06-23T23:59:59.000Z

467

Optimal adaptive sampling for continental shelf acoustic forecasting.  

Science Conference Proceedings (OSTI)

Shallow water acoustic propagation variability is driven by bathymetry and geo?acoustic and oceanographic variabilities. At the shelf?break

Kevin D. Heaney

2009-01-01T23:59:59.000Z

468

HYDROLASING OF CONTAMINATED UNDERWATER BASIN SURFACES AT THE HANFORD K-AREA  

SciTech Connect

This paper discusses selecting and Implementing hydrolasing technology to reduce radioactive contamination in preparing to dispose of the K Basins; two highly contaminated concrete basins at the Hanford Site. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities have begun for the remaining highly contaminated water, sludge, and concrete basin structures. Hydrolasing will be used to decontaminate and prepare the basin structures for disposal. The U. S. Department of Energy's (DOE) Hanford Site is considered the world's largest environmental cleanup project. The site covers 1,517 Km{sup 2} (586 square miles) along the Columbia River in an arid region of the northwest United States (U.S.). Hanford is the largest of the US former nuclear defense production sites. From the World War II era of the mid-1940s until the late-1980s when production stopped, Hanford produced 60 percent of the plutonium for nuclear defense and, as a consequence, produced a significant amount of environmental pollution now being addressed. Spent nuclear fuel was among the major challenges for DOE's environmental cleanup mission at Hanford. The end of production left Hanford with about 105,000 irradiated, solid uranium metal fuel assemblies--representing approximately 2,100 metric tons (80 percent of DOE's spent nuclear fuel). The fuel was ultimately stored in the K Basins water-filled, concrete basins attached to Hanford's K East (KE) and K West (KW) reactors. K Basin's fuel accounted for 95 percent of the total radioactivity in Hanford's former reactor production areas. Located about 457 meters (500 yards) from the Columbia River, the K Basins are two indoor, rectangular structures of reinforced concrete; each filled with more than 3.8 million liters (one million gallons) of water that has become highly contaminated with long-lived radionuclides. At the KW Basin, fuel was packaged and sealed in canisters. At the KE Basin, fuel was stored in open canisters that were exposed to water in the basin. The irradiated spent nuclear fuel corroded during long-term, wet storage; resulting in thousands of fuel assemblies becoming severely corroded and/or damaged. Corrosion, especially in the KE Basin, contributed to the formation of a layer of radioactive sludge in the basins. Sludge removal is now progressing and will be followed by dewatering and dispositioning the concrete structures. The DOE Richland Operations Office (RL) has given Fluor Hanford Inc./Fluor Government Group (Fluor) the task of preparing Hanford's K Basins for decontamination and disposal. Prior to dewatering, hydrolasing will be used to decontaminate the basin surfaces to prepare them for disposal. By removing highly contaminated surface layers of concrete, hydrolasing will be used to meet the dose objectives for protecting workers and complying with regulations for transporting demolition debris. Fluor has innovated, tested, and planned the application of the hydrolasing technology to meet the challenge of decontaminating highly radioactive concrete surfaces underwater. Newly existing technology is being adapted to this unique challenge.

CHRONISTER, G.B.

2005-06-14T23:59:59.000Z

469

Acoustical properties of drill strings  

DOE Green Energy (OSTI)

The recovery of petrochemical and geothermal resources requires extensive drilling of wells to increasingly greater depths. Real-time collection and telemetry of data about the drilling process while it occurs thousands of feet below the surface is an effective way of improving the efficiency of drilling operations. Unfortunately, due to hostile down-hole environments, telemetry of this data is an extremely difficult problem. Currently, commercial systems transmit data to the surface by producing pressure pulses within the portion of the drilling mud enclosed in the hollow steel drill string. Transmission rates are between two and four data bits per second. Any system capable of raising data rates without increasing the complexity of the drilling process will have significant economic impact. One alternative system is based upon acoustical carrier waves generated within the drill string itself. If developed, this method would accommodate data rates up to 100 bits per second. Unfortunately, the drill string is a periodic structure of pipe and threaded tool joints, the transmission characteristics are very complex and exhibit a banded and dispersive structure. Over the past forty years, attempts to field systems based upon this transmission method have resulted in little success. This paper examines this acoustical transmission problem in great detail. The basic principles of acoustic wave propagation in the periodic structure of the drill string are examined through theory, laboratory experiment, and field test. The results indicate the existence of frequency bands which are virtually free of attenuation and suitable for data transmission at high bit rates. 9 refs., 38 figs., 2 tabs.

Drumheller, D.S.

1988-08-01T23:59:59.000Z

470

Acoustically enhanced heat exchange and drying apparatus  

DOE Patents (OSTI)

A heat transfer drying apparatus includes an acoustically augmented heat transfer chamber for receiving material to be dried. The chamber includes a first heat transfer gas inlet, a second heat transfer gas inlet, a material inlet, and a gas outlet which also serves as a dried material and gas outlet. A non-pulsing first heat transfer gas source provides a first drying gas to the acoustically augmented heat transfer chamber through the first heat transfer gas inlet. A valveless, continuous second heat transfer gas source provides a second drying gas to the acoustically augmented heat transfer chamber through the second heat transfer gas inlet. The second drying gas also generates acoustic waves which bring about acoustical coupling with the gases in the acoustically augmented heat transfer chamber. The second drying gas itself oscillates at an acoustic frequency of approximately 180 Hz due to fluid mechanical motion in the gas. The oscillations of the second heat transfer gas coupled to the first heat transfer gas in the acoustically augmented heat transfer chamber enhance heat and mass transfer by convection within the chamber. 3 figs.

Bramlette, T.T.; Keller, J.O.

1987-07-10T23:59:59.000Z

471

Three-Dimensional Nonlinear Acoustical Holography  

E-Print Network (OSTI)

Nearfield Acoustical Holography (NAH) is an acoustic field visualization technique that can be used to reconstruct three-dimensional (3-D) acoustic fields by projecting two-dimensional (2-D) data measured on a hologram surface. However, linear NAH algorithms developed and improved by many researchers can result in significant reconstruction errors when they are applied to reconstruct 3-D acoustic fields that are radiated from a high-level noise source and include significant nonlinear components. Here, planar, nonlinear acoustical holography procedures are developed that can be used to reconstruct 3-D, nonlinear acoustic fields radiated from a high-level noise source based on 2-D acoustic pressure data measured on a hologram surface. The first nonlinear acoustic holography procedure is derived for reconstructing steady-state acoustic pressure fields by applying perturbation and renormalization methods to nonlinear, dissipative, pressure-based Westervelt Wave Equation (WWE). The nonlinear acoustic pressure fields radiated from a high-level pulsating sphere and an infinite-size, vibrating panel are used to validate this procedure. Although the WWE-based algorithm is successfully validated by those two numerical simulations, it still has several limitations: (1) Only the fundamental frequency and its second harmonic nonlinear components can be reconstructed; (2) the application of this algorithm is limited to mono-frequency source cases; (3) the effects of bent wave rays caused by transverse particle velocities are not included; (4) only acoustic pressure fields can be reconstructed. In order to address the limitations of the steady-state, WWE-based procedure, a transient, planar, nonlinear acoustic holography algorithm is developed that can be used to reconstruct 3-D nonlinear acoustic pressure and particle velocity fields. This procedure is based on Kuznetsov Wave Equation (KWE) that is directly solved by using temporal and spatial Fourier Transforms. When compared to the WWE-based procedure, the KWE-based procedure can be applied to multi-frequency source cases where each frequency component can contain both linear and nonlinear components. The effects of nonlinear bent wave rays can be also considered by using this algorithm. The KWE-based procedure is validated by conducting an experiment with a compression driver and four numerical simulations. The numerical and experimental results show that holographically-projected acoustic fields match well with directly-calculated and directly-measured fields.

Niu, Yaying

2013-05-01T23:59:59.000Z

472

AquaOptical: a lightweight device for high-rate long-range underwater point-to-point communication  

E-Print Network (OSTI)

This paper describes AquaOptical, an underwater optical communication system. Three optical modems have been developed: a long range system, a short range system, and a hybrid. We describe their hardware and software ...

Doniec, Marek Wojciech

473

Design of an autonomous underwater vehicle to evaluate the blazed array sonar and simultaneous localization and mapping algorithms  

E-Print Network (OSTI)

This thesis has investigated aspects of the design of a new highly maneuverable Autonomous Underwater Vehicle - the XAUV. The overall goal for the design of this vehicle is to create a small, highly maneuverable AUV that ...

Uhle, Matthew William

2007-01-01T23:59:59.000Z

474

Lossy compression and real-time geovisualization for ultra-low bandwidth telemetry from untethered underwater vehicles  

E-Print Network (OSTI)

Oceanographic applications of robotics are as varied as the undersea environment itself. As underwater robotics moves toward the study of dynamic processes with multiple vehicles, there is an increasing need to distill ...

Murphy, Christopher Alden

2008-01-01T23:59:59.000Z

475

Passive Acoustic Detection and Measurement of Rainfall at Sea  

Science Conference Proceedings (OSTI)

Rainfall over the ocean is one of the most important climatic parameters for both oceanic and atmospheric science. Traditional accumulation-type rain gauges are difficult to operate at sea, and so an alternate technique using underwater sound has ...

Barry B. Ma; Jeffrey A. Nystuen

2005-08-01T23:59:59.000Z

476

Acoustic Logs At Steamboat Springs Area (Combs, Et Al., 1999) | Open Energy  

Open Energy Info (EERE)

Steamboat Springs Area (Combs, Et Al., 1999) Steamboat Springs Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Acoustic Logs At Steamboat Springs Area (Combs, Et Al., 1999) Exploration Activity Details Location Steamboat Springs Area Exploration Technique Acoustic Logs Activity Date Usefulness useful DOE-funding Unknown Notes Two other Sandia instruments were used briefly: the acoustic borehole televiewer (BHTV) yielded wellbore images down to 520';and a Sandia memory tool gave pressuretemperature data for a shut-in test at the end of the project. Because no oriented core has been collected in this field, the televiewer images giving fracture direction were extremely M.ormative, but the BHTV could not be used at greater depths because of its temperature

477

Speaker verification system using acoustic data and non-acoustic data  

DOE Patents (OSTI)

A method and system for speech characterization. One embodiment includes a method for speaker verification which includes collecting data from a speaker, wherein the data comprises acoustic data and non-acoustic data. The data is used to generate a template that includes a first set of "template" parameters. The method further includes receiving a real-time identity claim from a claimant, and using acoustic data and non-acoustic data from the identity claim to generate a second set of parameters. The method further includes comparing the first set of parameters to the set of parameters to determine whether the claimant is the speaker. The first set of parameters and the second set of parameters include at least one purely non-acoustic parameter, including a non-acoustic glottal shape parameter derived from averaging multiple glottal cycle waveforms.

Gable, Todd J. (Walnut Creek, CA); Ng, Lawrence C. (Danville, CA); Holzrichter, John F. (Berkeley, CA); Burnett, Greg C. (Livermore, CA)

2006-03-21T23:59:59.000Z

478

Acoustically enhanced heat exchange and drying apparatus  

DOE Patents (OSTI)

A heat transfer apparatus includes a first chamber having a first heat transfer gas inlet, a second heat transfer gas inlet, and an outlet. A first heat transfer gas source provides a first gas flow to the first chamber through the first heat transfer gas inlet. A second gas flow through a second chamber connected to the side of the first chamber, generates acoustic waves which bring about acoustical coupling of the first and second gases in the acoustically augmented first chamber. The first chamber may also include a material inlet for receiving material to be dried, in which case the gas outlet serves as a dried material and gas outlet.

Bramlette, T. Tazwell (Livermore, CA); Keller, Jay O. (Oakland, CA)

1989-01-01T23:59:59.000Z

479

Copper vapor laser acoustic thermometry system  

DOE Patents (OSTI)

A copper vapor laser (CVL) acoustic thermometry system is disclosed. The invention couples an acoustic pulse a predetermined distance into a laser tube by means of a transducer and an alumina rod such that an echo pulse is returned along the alumina rod to the point of entry. The time differential between the point of entry of the acoustic pulse into the laser tube and the exit of the echo pulse is related to the temperature at the predetermined distance within the laser tube. This information is processed and can provide an accurate indication of the average temperature within the laser tube.

Galkowski, J.J.

1986-08-27T23:59:59.000Z

480

Particle collection enhancement by acoustics  

SciTech Connect

The overall objective of this project is to demonstrate pulse combustion induced acoustic enhancement of coal ash agglomeration and sulfur capture efficiency at conditions typical of proposed direct coal-fired turbines. The MTCI proprietary approach results in agglomerates that allow the use of conventional cyclones to achieve very high particulate collection efficiency and eliminates the need for barrier filters which pose concerns regarding durability and economics. The goal of the program is to support the mission of the Department of Energy (DOE) for developing coal-fired combustion gas turbines. The MTCI concept can be packaged either as a hot flue gas clean-up subsystem for the existing combustor island configurations or as an alterative primary pulse combustor island with integrated sulfur capture, particulate agglomeration and capture, alkali gettering and NO{sub x} emissions control.

Mansour, M.N.; Chandran, R.R.; Duqum, J.N. [Manufacturing and Technology Conversion International, Inc., Columbia, MD (United States); Scaroni, A.W.; Koopman, G.H. [Pennsylvania State Univ., University Park, PA (United States); Loth, J.L. [West Virginia Univ., Morgantown, WV (United States)

1993-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "underwater active acoustic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Enforcing heritage law in Dutch waters. The enforcement of the provisions of the Monuments and Historic Buildings Act on illegal excavation of underwater cultural heritage.  

E-Print Network (OSTI)

??This study focuses on illegal excavation as a threat to underwater cultural heritage in the Netherlands. More specifically, it deals with enforcement of legal protection… (more)

Ziengs, Leon

2012-01-01T23:59:59.000Z

482

Characterization of acoustic signals due to surface discharges on H.V. glass insulators using wavelet radial basis function neural networks  

Science Conference Proceedings (OSTI)

A hybrid model incorporating wavelet and radial basis function neural network is presented which is used to detect, identify and characterize the acoustic signals due to surface discharge activity and hence differentiate abnormal operating conditions ... Keywords: Acoustic signal, Dry bands, Glass insulator, RBF-NN, Surface discharge, Wavelet transform

Nasir A. Al-geelani; M. Afendi M. Piah; Redhwan Q. Shaddad

2012-04-01T23:59:59.000Z

483

CX-009160: Categorical Exclusion Determination  

Energy.gov (U.S. Department of Energy (DOE))

Underwater Active Acoustic Monitoring Network for Marine and Hydrokinetic Energy Projects CX(s) Applied: B3.3 Date: 09/24/2012 Location(s): Maine Offices(s): Golden Field Office

484

ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS  

SciTech Connect

The research during this project has concentrated on developing a correlation between rock deformation mechanisms and their acoustic velocity signature. This has included investigating: (1) the acoustic signature of drained and undrained unconsolidated sands, (2) the acoustic emission signature of deforming high porosity rocks (in comparison to their low porosity high strength counterparts), (3) the effects of deformation on anisotropic elastic and poroelastic moduli, and (4) the acoustic tomographic imaging of damage development in rocks. Each of these four areas involve triaxial experimental testing of weak porous rocks or unconsolidated sand and involves measuring acoustic properties. The research is directed at determining the seismic velocity signature of damaged rocks so that 3-D or 4-D seismic imaging can be utilized to image rock damage. These four areas of study are described in the report: (1) Triaxial compression experiments have been conducted on unconsolidated Oil Creek sand at high confining pressures. (2) Initial experiments on measuring the acoustic emission activity from deforming high porosity Danian chalk were accomplished and these indicate that the AE activity was of a very low amplitude. (3) A series of triaxial compression experiments were conducted to investigate the effects of induced stress on the anisotropy developed in dynamic elastic and poroelastic parameters in rocks. (4) Tomographic acoustic imaging was utilized to image the internal damage in a deforming porous limestone sample. Results indicate that the deformation damage in rocks induced during laboratory experimentation can be imaged tomographically in the laboratory. By extension the results also indicate that 4-D seismic imaging of a reservoir may become a powerful tool for imaging reservoir deformation (including imaging compaction and subsidence) and for imaging zones where drilling operation may encounter hazardous shallow water flows.

Thurman E. Scott, Jr.; Younane Abousleiman

2004-04-01T23:59:59.000Z

485

Building Energy Software Tools Directory: Acoustics Program  

NLE Websites -- All DOE Office Websites (Extended Search)

Acoustics Program Acoustics Program Developed to help designers accurately model the sound level reaching building tenant's ears, the Trane Acoustics Program (TAP) "projects" equipment sound power data through the surroundings (e.g., floors, ductwork, walls), to estimate the sound level that will be heard. Industry-standard calculations published by ASHRAE's 1991 Algorithms for HVAC Acoustics handbook are the basis for this estimate. In TAP, you can model the conditions of an HVAC system by choosing specific equipment and building component criteria. TAP will analyze the sound path and calculate the total effect for the enclosed space. You can continuously adjust the data and system design criteria to compare the results effortlessly. TAP will even plot presentation quality graphs of

486

Errors in Radio Acoustic Sounding of Temperature  

Science Conference Proceedings (OSTI)

With the use of simultaneous correction for radial wind, the accuracy of radio acoustic sounding systems for the measurement of temperature has been substantially improved. The temperature accuracy can now be affected by a number of factors that ...

Wayne M. Angevine; W. L. Ecklund

1994-06-01T23:59:59.000Z

487

Audioptimization : global-based acoustic design  

E-Print Network (OSTI)

Acoustic design is a difficult problem, because the human perception of sound depends on such things as decibel level, direction of propagation, and attenuation over time, none of which are tangible or visible. The advent ...

Monks, Michael Christopher, 1958-

1999-01-01T23:59:59.000Z

488

Weather Classification Using Passive Acoustic Drifters  

Science Conference Proceedings (OSTI)

Weather observations are needed in remote oceanic regions to support numerical weather forecast models, to provide surface truth for satellite sensors, and to help understand global weather patterns. An acoustic mini-drifting buoy using no moving ...

Jeffrey A. Nystuen; Harry D. Selsor

1997-06-01T23:59:59.000Z

489

An Acoustic Doppler and Electromagnetic Velocity Profiler  

Science Conference Proceedings (OSTI)

A freely failing current meter called the Absolute Velocity Profiler (AVP) is described. This profiler is an expansion of a previously developed instrument, the Electro-Magnetic Velocity Profiler (EMVP), with the additional capability of acoustic ...

Thomas B. Sanford; Robert G. Driver; John H. Dunlap

1985-06-01T23:59:59.000Z

490

Scattering of ion-acoustic solitons  

SciTech Connect

A series of experiments is described that is designed to ascertain the properties of the scattering of planar ion-acoustic solitons from objects of various shapes. The scattered solitons are compared with those radiated from the same objects.

Raychaudhuri, S.; Chang, H.; Tsikis, E.K.; Lonngren, K.E.

1985-07-01T23:59:59.000Z

491

Global Ocean Warming: An Acoustic Measure?  

Science Conference Proceedings (OSTI)

Explosions of 300 lbs of TNT at 1 km depth off Perth, Australia were recorded on Bermuda hydrophones, demonstrating 30 years age the feasibility of global acoustic transmissions. Climate-induced changes in ocean temperature (and hence in sound ...

W. H. Munk; A. M. G. Forbes

1989-11-01T23:59:59.000Z

492

Acoustic Energy Storage in Single Bubble Sonoluminescence  

E-Print Network (OSTI)

Single bubble sonoluminescence is understood in terms of a shock focusing towards the bubble center. We present a mechanism for significantly enhancing the effect of shock focusing, arising from the storage of energy in the acoustic modes of the gas. The modes with strongest coupling are not spherically symmetric. The storage of acoustic energy gives a framework for understanding how light intensities depend so strongly on ambient gases and liquids and suggests that the light intensities of successive flashes are highly correlated.

Michael P. Brenner; Sascha Hilgenfeldt; Detlef Lohse; Rodolfo R. Rosales

1996-05-07T23:59:59.000Z

493

Tunable damper for an acoustic wave guide  

DOE Patents (OSTI)

A damper for tunably damping acoustic waves in an ultrasonic waveguide is provided which may be used in a hostile environment such as a nuclear reactor. The area of the waveguide, which may be a selected size metal rod in which acoustic waves are to be damped, is wrapped, or surrounded, by a mass of stainless steel wool. The wool wrapped portion is then sandwiched between tuning plates, which may also be stainless steel, by means of clamping screws which may be adjusted to change the clamping force of the sandwiched assembly along the waveguide section. The plates are preformed along their length in a sinusoidally bent pattern with a period approximately equal to the acoustic wavelength which is to be damped. The bent pattern of the opposing plates are in phase along their length relative to their sinusoidal patterns so that as the clamping screws are tightened a bending stress is applied to the waveguide at 180/sup 0/ intervals along the damping section to oppose the acoustic wave motions in the waveguide and provide good coupling of the wool to the guide. The damper is tuned by selectively tightening the clamping screws while monitoring the amplitude of the acoustic waves launched in the waveguide. It may be selectively tuned to damp particular acoustic wave modes (torsional or extensional, for example) and/or frequencies while allowing others to pass unattenuated.

Rogers, S.C.

1982-10-21T23:59:59.000Z

494

Tunable damper for an acoustic wave guide  

DOE Patents (OSTI)

A damper for tunably damping acoustic waves in an ultrasonic waveguide is provided which may be used in a hostile environment such as a nuclear reactor. The area of the waveguide, which may be a selected size metal rod in which acoustic waves are to be damped, is wrapped, or surrounded, by a mass of stainless steel wool. The wool wrapped portion is then sandwiched between tuning plates, which may also be stainless steel, by means of clamping screws which may be adjusted to change the clamping force of the sandwiched assembly along the waveguide section. The plates are preformed along their length in a sinusoidally bent pattern with a period approximately equal to the acoustic wavelength which is to be damped. The bent pattern of the opposing plates are in phase along their length relative to their sinusoidal patterns so that as the clamping screws are tightened a bending stress is applied to the waveguide at 180.degree. intervals along the damping section to oppose the acoustic wave motions in the waveguide and provide good coupling of the wool to the guide. The damper is tuned by selectively tightening the clamping screws while monitoring the amplitude of the acoustic waves launched in the waveguide. It may be selectively tuned to damp particular acoustic wave modes (torsional or extensional, for example) and/or frequencies while allowing others to pass unattenuated.

Rogers, Samuel C. (Knoxville, TN)

1984-01-01T23:59:59.000Z

495

Apparatus for separating particles utilizing engineered acoustic contrast capture particles  

DOE Patents (OSTI)

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Kaduchak, Gregory (Los Alamos, NM); Ward, Michael D. (Los Alamos, NM)

2011-12-27T23:59:59.000Z

496

Comparative Performance of Acoustic-tagged and PIT-tagged Juvenile Salmonids  

DOE Green Energy (OSTI)

Numerous research tools and technologies are currently being used to evaluate fish passage and survival to determine the impacts of the Federal Columbia River Power System (FCRPS) on endangered and threatened juvenile salmonids, including PIT tags, balloon tags, hydroacoustic evaluations, radio telemetry, and acoustic telemetry. Each has advantages and disadvantages, but options are restricted in some situations because of limited capabilities of a specific technology, lack of detection capability downstream, or availability of adequate numbers of fish. However, there remains concern about the comparative effects of the tag or the tagging procedure on fish performance. The recently developed Juvenile Salmonid Acoustic Telemetry System (JSATS) acoustic transmitter is the smallest active acoustic tag currently available. The goal of this study was to determine whether fish tagged with the JSATS acoustic-telemetry tag can provide unbiased estimates of passage behavior and survival within the performance life of the tag. We conducted both field and laboratory studies to assess tag effects. For the field evaluation we released a total of 996 acoustic-tagged fish in conjunction with 21,026 PIT-tagged fish into the tailrace of Lower Granite Dam on 6 and 13 May. Travel times between release and downstream dams were not significantly different for the majority of the reaches between acoustic-tagged and PIT-tagged fish. In addition to the field evaluation, a series of laboratory experiments were conducted to determine if growth and survival of juvenile Chinook salmon surgically implanted with acoustic transmitters is different than untagged or PIT tagged juvenile Chinook salmon. Only yearling fish with integrated and non-integrated transmitters experienced mortalities, and these were low (<4.5%). Mortality among sub-yearling control and PIT-tag treatments ranged up to 7.7% while integrated and non-integrated treatments had slightly higher rates (up to 8.3% and 7.9% respectively). No acoustic transmitters were shed by yearling fish during the course of the 90 day study. Up to 7.8% of subyearling fish expelled transmitters. Tags were expelled from 5 to 63 days post-surgery. The average time to expulsion was 27 days; few fish expelled transmitters within 14 days of implantation or less. Histological results suggest that inflammation associated with implantation of an acoustic transmitter can produce fibrous tissue which can invade and possibly damage internal organs soon after implantation. Reactions severe enough to damage organs however, were limited to only ~20% of subyearling Chinook salmon, all of which were under 101mm and 12g at tagging. The infiltration of the fibrous tissue into organs was observed most often in fish held for 21 days and appeared to decrease in subsequent holding times.

Hockersmith, Eric E.; Brown, Richard S.; Liedtke, Theresa L.

2008-02-01T23:59:59.000Z

497

Comparative Performance of Acoustic-tagged and PIT-tagged Juvenile Salmonids  

Science Conference Proceedings (OSTI)

Numerous research tools and technologies are currently being used to evaluate fish passage and survival to determine the impacts of the Federal Columbia River Power System (FCRPS) on endangered and threatened juvenile salmonids, including PIT tags, balloon tags, hydroacoustic evaluations, radio telemetry, and acoustic telemetry. Each has advantages and disadvantages, but options are restricted in some situations because of limited capabilities of a specific technology, lack of detection capability downstream, or availability of adequate numbers of fish. However, there remains concern about the comparative effects of the tag or the tagging procedure on fish performance. The recently developed Juvenile Salmonid Acoustic Telemetry System (JSATS) acoustic transmitter is the smallest active acoustic tag currently available. The goal of this study was to determine whether fish tagged with the JSATS acoustic-telemetry tag can provide unbiased estimates of passage behavior and survival within the performance life of the tag. We conducted both field and laboratory studies to assess tag effects. For the field evaluation we released a total of 996 acoustic-tagged fish in conjunction with 21,026 PIT-tagged fish into the tailrace of Lower Granite Dam on 6 and 13 May. Travel times between release and downstream dams were not significantly different for the majority of the reaches between acoustic-tagged and PIT-tagged fish. In addition to the field evaluation, a series of laboratory experiments were conducted to determine if growth and survival of juvenile Chinook salmon surgically implanted with acoustic transmitters is different than untagged or PIT tagged juvenile Chinook salmon. Only yearling fish with integrated and non-integrated transmitters experienced mortalities, and these were low (tag treatments ranged up to 7.7% while integrated and non-integrated treatments had slightly higher rates (up to 8.3% and 7.9% respectively). No acoustic transmitters were shed by yearling fish during the course of the 90 day study. Up to 7.8% of subyearling fish expelled transmitters. Tags were expelled from 5 to 63 days post-surgery. The average time to expulsion was 27 days; few fish expelled transmitters within 14 days of implantation or less. Histological results suggest that inflammation associated with implantation of an acoustic transmitter can produce fibrous tissue which can invade and possibly damage internal organs soon after implantation. Reactions severe enough to damage organs however, were limited to only ~20% of subyearling Chinook salmon, all of which were under 101mm and 12g at tagging. The infiltration of the fibrous tissue into organs was observed most often in fish held for 21 days and appeared to decrease in subsequent holding times.

Hockersmith, Eric E.; Brown, Richard S.; Liedtke, Theresa L.

2008-02-01T23:59:59.000Z

498

Direct observation of dynamic surface acoustic wave controlled carrier injection into single quantum posts using phase-resolved optical spectroscopy  

E-Print Network (OSTI)

A versatile stroboscopic technique based on active phase-locking of a surface acoustic wave to picosecond laser pulses is used to monitor dynamic acoustoelectric effects. Time-integrated multi-channel detection is applied to probe the modulation of the emission of a quantum well for different frequencies of the surface acoustic wave. For quantum posts we resolve dynamically controlled generation of neutral and charged excitons and preferential injection of holes into localized states within the nanostructure.

Völk, S; Schülein, F J R; Truong, T A; Kim, H; Petroff, P M; Wixforth, A; Krenner, H J

2010-01-01T23:59:59.000Z

499

Direct observation of dynamic surface acoustic wave controlled carrier injection into single quantum posts using phase-resolved optical spectroscopy  

E-Print Network (OSTI)

A versatile stroboscopic technique based on active phase-locking of a surface acoustic wave to picosecond laser pulses is used to monitor dynamic acoustoelectric effects. Time-integrated multi-channel detection is applied to probe the modulation of the emission of a quantum well for different frequencies of the surface acoustic wave. For quantum posts we resolve dynamically controlled generation of neutral and charged excitons and preferential injection of holes into localized states within the nanostructure.

S. Völk; F. Knall; F. J. R. Schülein; T. A. Truong; H. Kim; P. M. Petroff; A. Wixforth; H. J. Krenner

2010-11-08T23:59:59.000Z

500

Imaging of Acoustic Waves in Sand  

SciTech Connect

There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

2003-08-01T23:59:59.000Z