An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems
Abstract
It was hypothesized that the variations in time to solution are driven by the competing mechanisms of exploration and exploitation.This thesis explores this hypothesis by examining two contrasting problems that embody the hypothesized tradeoff between exploration and exploitation. Plus one recall store (PORS) is an optimization problem based on the idea of a simple calculator with four buttons: plus, one, store, and recall. Integer addition and store are classified as operations, and one and memory recall are classified as terminals. The goal is to arrange a fixed number of keystrokes in a way that maximizes the numerical result. PORS 15 (15 keystrokes) represents the subset of difficult PORS problems and PORS 16 (16 keystrokes) represents the subset of PORS problems that are easiest to optimize. The goal of this work is to examine the tradeoff between exploitation and exploration in graph based evolutionary algorithm (GBEA) optimization. To do this, computational experiments are used to examine how solutions evolve in PORS 15 and 16 problems when solved using GBEAs. The experiment is comprised of three components; the graphs and the population, the evolutionary algorithm rule set, and the example problems. The complete, hypercube, and cycle graphs were used for this experiment.more »
 Authors:
 Iowa State Univ., Ames, IA (United States)
 Publication Date:
 Research Org.:
 Ames Laboratory (AMES), Ames, IA (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC)
 OSTI Identifier:
 1048523
 Report Number(s):
 IST 3056
 DOE Contract Number:
 AC0207CH11358
 Resource Type:
 Thesis/Dissertation
 Country of Publication:
 United States
 Language:
 English
 Subject:
 97 MATHEMATICS AND COMPUTING
Citation Formats
Koch, Kaelynn. An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems. United States: N. p., 2012.
Web. doi:10.2172/1048523.
Koch, Kaelynn. An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems. United States. doi:10.2172/1048523.
Koch, Kaelynn. 2012.
"An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems". United States.
doi:10.2172/1048523. https://www.osti.gov/servlets/purl/1048523.
@article{osti_1048523,
title = {An investigation of exploitation versus exploration in GBEA optimization of PORS 15 and 16 Problems},
author = {Koch, Kaelynn},
abstractNote = {It was hypothesized that the variations in time to solution are driven by the competing mechanisms of exploration and exploitation.This thesis explores this hypothesis by examining two contrasting problems that embody the hypothesized tradeoff between exploration and exploitation. Plus one recall store (PORS) is an optimization problem based on the idea of a simple calculator with four buttons: plus, one, store, and recall. Integer addition and store are classified as operations, and one and memory recall are classified as terminals. The goal is to arrange a fixed number of keystrokes in a way that maximizes the numerical result. PORS 15 (15 keystrokes) represents the subset of difficult PORS problems and PORS 16 (16 keystrokes) represents the subset of PORS problems that are easiest to optimize. The goal of this work is to examine the tradeoff between exploitation and exploration in graph based evolutionary algorithm (GBEA) optimization. To do this, computational experiments are used to examine how solutions evolve in PORS 15 and 16 problems when solved using GBEAs. The experiment is comprised of three components; the graphs and the population, the evolutionary algorithm rule set, and the example problems. The complete, hypercube, and cycle graphs were used for this experiment. A fixed population size was used.},
doi = {10.2172/1048523},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2012,
month = 1
}

The time pattern of extraction and consumption chosen in the centrallyplanned Soviet economy is the result of decisions made at many levels of the economic hierarchy in response to a variety of signals. In this dissertation, the conditions for the optimal exploitation of nonrenewable resources first derived in Harol Hotelling's classic article are used as a standard against which to judge Soviet practices. The familiar Western theory is adapted to describe the decisionmaking process in the Soviet extractive branches in order to investigate the hypothesis that a number of features of the Soviet economy are likely to lead to amore »

Decomposition of structured largescale optimization problems and parallel optimization
Blockangular linearprogramming problems and linear multicommodity network optimization problems can be cast into a form given. In the approach, the Rockafellar dual of the problem is taken to arrive at an unconstrained nonsmooth maximization problem. The difficulty arises from the nonsmoothness of the dual objective. Traditional subgradient methods are not good enough as they do not have implementable stopping criteria and are reported to have slow convergence. One also may not obtain a primal solution at the end. Instead, a modified bundle algorithm is applied that has an implementable stopping criterion, and more importantly, one can recover an approximate primalmore » 
Dynamic optimization approach to modeling petroleum exploration with an application to the 1986 oil price decline
A longstanding problem with econometric oil and gas supply models is the lack of a dynamic optimization framework that incorporates expectations of future prices and costs as a basis for the econometric equations. This dissertation attempts to remedy this problem by using a rationalexpectations model of the United States oil market in which a representative competitive firm chooses an exploratory drilling plan so as to maximize the expected discounted net present value of oil discoveries. The quadratic objective function and linear laws of motion for exogenous variables lead to a linear exploratory drilling decision rule. This decision rule is thenmore » 
Construction work in progress in the rate base versus allowance for funds used during construction: an investigation of the effects on capital intensity in electric utilities
The allowance for funds used during construction accounting procedure has been giving way to construction work in progress in the rate base in recent years for many regulated electric utility companies. As of 1976, more than onehalf of all state utility commissions permit all or a portion of construction work in progress in the rate base for at least one electric utility under their regulatory authority, compared with less than onefourth at the beginning of the 1970's. This dissertation investigates the effects on capital intensity of allowing construction work in progress in the rate base. The basic null hypothesis thatmore » 
Investigation of the relative abundance of heavy versus light nuclei in primary cosmic rays using underground muon bundles
We study multiple muon events (muon bundles) recorded underground at a depth of 2090 mwe. To penetrate to this depth, the muons must have energies above 0.8 TeV at the Earth`s surface; the primary cosmic ray nuclei which give rise to the observed muon bundles have energies at incidence upon the upper atmosphere of 10 to 10 ^{5}TeV. The events are detected using the Soudan 2 experiment`s fine grained tracking calorimeter which is surrounded by a 14 m x 10 m x 31 m proportional tube array (the ``active shield``). Muon bundles which have at least one muon traversing themore »