Garrison Greenwood | Portland State University (original) (raw)

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Papers by Garrison Greenwood

Research paper thumbnail of A methodology for mapping pipelined algorithms onto hypercube arrays /

Research paper thumbnail of Attaining Fault Tolerance through Self-adaption: The Strengths and Weaknesses of Evolvable Hardware Approaches

Research paper thumbnail of Fault recovery in linear systems via intrinsic evolution

Research paper thumbnail of EARP-1 - An evolvable analog research platform

Research paper thumbnail of A Multi-Agent System for Autonomous Adaptive Control of a Flapping-Wing Micro Air Vehicle

2015 IEEE Symposium Series on Computational Intelligence, 2015

Research paper thumbnail of So many algorithms. So little time

Acm Sigsoft Software Engineering Notes, Mar 1, 1997

ABSTRACT

Research paper thumbnail of Does the moran process hinder our understanding of cooperation in human populations?

2014 Ieee Conference on Computational Intelligence and Games, Aug 1, 2014

Research paper thumbnail of Static task allocation using (�, ?) evolutionary strategies

Research paper thumbnail of Finding Solutions to NP Problems: Philosophical Difference Between Quantum and Evolutionary Search Algorithms

Cec, Oct 5, 2000

There is no known polynomial-time algorithm that can solve an NP problem. Evolutionary search has... more There is no known polynomial-time algorithm that can solve an NP problem. Evolutionary search has been shown to be a viable method of finding acceptable solutions within a reasonable time period. Recently quantum computers have surfaced as another alternative method. But these two methods use radically different philosophies for solving NP problems even though both search methods are non-deterministic. This paper uses instances of {\bf SAT}, {\bf 3SAT} and {\bf TSP} to describe how these two methods differ in their approach to solving NP problems.

Research paper thumbnail of The state of engineering management: a view from the trenches

Research paper thumbnail of Emotions and Their Effect on Cooperation Levels in N-Player Social Dilemma Games

Lecture Notes in Computer Science, 2015

Research paper thumbnail of Evolving N-person social dilemma strategies to resolve questions on participation in climate change programs

Proceedings of the 2010 IEEE Conference on Computational Intelligence and Games, 2010

This paper describes an N -person social dilemma game created to study how climate change agreeme... more This paper describes an N -person social dilemma game created to study how climate change agreement strategies develop. The players in this game are trying to collect a target amount for a climate fund. Players fall into three categories: cooperators who contribute their fair share, altruists who contribute more than their fair share and defectors who contribute nothing. In all cases we would evolve a set of player strategies that collected the target sum (-0%/+0.5%). Our results indicate defection is a preferred strategy, but group-level reciprocity or non-altruistic punishment from a third party can dramatically increase levels of cooperation.

Research paper thumbnail of Using discrete fourier transforms to detect operational environments for autonomous nonlinear systems

2011 Conference Record of the Forty Fifth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2011

The proportional-integrative-derivative (PID) controller provides effective control in linear sys... more The proportional-integrative-derivative (PID) controller provides effective control in linear systems. However, performance is poor in nonlinear systems unless combined with a fuzzy logic controller (FLC) that modifies the PID controller gains as needed. System behavior can adapt to operational environment changes by switching different FLCs online. But that capability requires accurate operational environment identification. Identification must be done without human intervention in autonomous systems. This paper describes how Discrete Fourier Transforms can identify operational environments in an autonomous nonlinear system. Simulation results indicate the proposed method accurately identifies the environment and switches the correct FLC online to adapt the system's behavior.

Research paper thumbnail of Teaching hardware description languages to satisfy industry expectations

International Journal of Electrical Engineering Education, 2009

ABSTRACT

Research paper thumbnail of A tag-mediated game designed to study cooperation in human populations

2013 IEEE Conference on Computational Inteligence in Games (CIG), 2013

ABSTRACT How and why cooperation develops in human populations is not known. The iterated prisone... more ABSTRACT How and why cooperation develops in human populations is not known. The iterated prisoner's dilemma game provides a natural framework for studying cooperation growth in human populations. However, recent experiments with human subjects has exposed a number of serious flaws in virtually all of the game-theoretical models that have appeared in the literature. Indeed, some experiments suggest network reciprocity-thought to be essential for cooperation in human populationsmay actually play no role whatsoever. In this paper we briefly review some human experiments that were conducted in the last three years. We then present preliminary results of a new tag-mediated model designed for studying cooperation in human populations. The model exhibits many characteristics found in the human experiments including assortment, which many researchers now believe is necessary for maintaining cooperation.

Research paper thumbnail of On the value of operator-induced neighborhoods in fitness landscapes

2011 IEEE Congress of Evolutionary Computation (CEC), 2011

ABSTRACT All of the solutions to a combinatorial optimization problem can be collected into a fit... more ABSTRACT All of the solutions to a combinatorial optimization problem can be collected into a fitness landscape. Often these landscapes are huge, making an exhaustive search for the best solution impractical. Stochastic search algorithms work best if the search operators are tailored to the fitness landscape structure. Some researchers claim this structure is induced by the search operator itself. In this paper we show structural information obtained from operator-induced neighborhoods can be completely misleading unless specific ordering has prevailed during the mapping process and appropriate isomorphic proofs have been made.

Research paper thumbnail of Fault Recovery Using Evolvable Fuzzy Systems

2007 IEEE Workshop on Evolvable and Adaptive Hardware (WEAH2007), 2007

Autonomous systems must survive for long periods without relying on humans for fault recovery. Fa... more Autonomous systems must survive for long periods without relying on humans for fault recovery. Faults may be impossible to analyze remotely and redundant hardware is frequently not allowed. The only recourse may be to replace the existing control strategy. This paper proposes a fuzzy logic controller architecture that executes a replacement control strategy for autonomous systems. This paper shows this architecture is ideally suited for fault recovery in autonomous systems with imprecisely defined faults. The controller is evolved in-situ and evaluated intrinsically

Research paper thumbnail of Using ant colony optimization to find low energy atomic cluster structures

2005 Ieee Congress on Evolutionary Computation, Oct 2, 2005

Over the past 20 years atomic cluster structures have been intensively studied because of their i... more Over the past 20 years atomic cluster structures have been intensively studied because of their importance in physics, chemistry and recently material science. Unfortunately finding the lowest energy structure, which is the most stable configuration, is NP-hard. In this paper we present preliminary results on an ant colony optimization algorithm used in conjunction with a Monte Carlo sampling method to find low energy configurations of small silicon atomic clusters.

Research paper thumbnail of An Evolutionary Approach to Hardware/Software Partitioning

In this paper, we present an approach to hardware software codesign of real-time embedded systems... more In this paper, we present an approach to hardware software codesign of real-time embedded systems. Two of the di culties associated with codesign are handling tradeo s among multiple attributes and exploring a large design space. We use a combination of techniques from the evolutionary computation and utility theory elds to address these problem areas. A real-time microcontroller-based design example is presented to illustrate our approach.

Research paper thumbnail of Characterization of attractors in speech signals

Biosystems, Feb 1, 1997

It is shown that speech signals can have attractors with fractal dimension. A method for estimati... more It is shown that speech signals can have attractors with fractal dimension. A method for estimating this dimension is given. The existence of this attractor suggests that statistical models for speech may be inappropriate. Moreover, the dimension of this attractor is a lower bound on the order of a linear prediction model. © 1997 Elsevier Science Ireland Ltd.

Research paper thumbnail of A methodology for mapping pipelined algorithms onto hypercube arrays /

Research paper thumbnail of Attaining Fault Tolerance through Self-adaption: The Strengths and Weaknesses of Evolvable Hardware Approaches

Research paper thumbnail of Fault recovery in linear systems via intrinsic evolution

Research paper thumbnail of EARP-1 - An evolvable analog research platform

Research paper thumbnail of A Multi-Agent System for Autonomous Adaptive Control of a Flapping-Wing Micro Air Vehicle

2015 IEEE Symposium Series on Computational Intelligence, 2015

Research paper thumbnail of So many algorithms. So little time

Acm Sigsoft Software Engineering Notes, Mar 1, 1997

ABSTRACT

Research paper thumbnail of Does the moran process hinder our understanding of cooperation in human populations?

2014 Ieee Conference on Computational Intelligence and Games, Aug 1, 2014

Research paper thumbnail of Static task allocation using (�, ?) evolutionary strategies

Research paper thumbnail of Finding Solutions to NP Problems: Philosophical Difference Between Quantum and Evolutionary Search Algorithms

Cec, Oct 5, 2000

There is no known polynomial-time algorithm that can solve an NP problem. Evolutionary search has... more There is no known polynomial-time algorithm that can solve an NP problem. Evolutionary search has been shown to be a viable method of finding acceptable solutions within a reasonable time period. Recently quantum computers have surfaced as another alternative method. But these two methods use radically different philosophies for solving NP problems even though both search methods are non-deterministic. This paper uses instances of {\bf SAT}, {\bf 3SAT} and {\bf TSP} to describe how these two methods differ in their approach to solving NP problems.

Research paper thumbnail of The state of engineering management: a view from the trenches

Research paper thumbnail of Emotions and Their Effect on Cooperation Levels in N-Player Social Dilemma Games

Lecture Notes in Computer Science, 2015

Research paper thumbnail of Evolving N-person social dilemma strategies to resolve questions on participation in climate change programs

Proceedings of the 2010 IEEE Conference on Computational Intelligence and Games, 2010

This paper describes an N -person social dilemma game created to study how climate change agreeme... more This paper describes an N -person social dilemma game created to study how climate change agreement strategies develop. The players in this game are trying to collect a target amount for a climate fund. Players fall into three categories: cooperators who contribute their fair share, altruists who contribute more than their fair share and defectors who contribute nothing. In all cases we would evolve a set of player strategies that collected the target sum (-0%/+0.5%). Our results indicate defection is a preferred strategy, but group-level reciprocity or non-altruistic punishment from a third party can dramatically increase levels of cooperation.

Research paper thumbnail of Using discrete fourier transforms to detect operational environments for autonomous nonlinear systems

2011 Conference Record of the Forty Fifth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2011

The proportional-integrative-derivative (PID) controller provides effective control in linear sys... more The proportional-integrative-derivative (PID) controller provides effective control in linear systems. However, performance is poor in nonlinear systems unless combined with a fuzzy logic controller (FLC) that modifies the PID controller gains as needed. System behavior can adapt to operational environment changes by switching different FLCs online. But that capability requires accurate operational environment identification. Identification must be done without human intervention in autonomous systems. This paper describes how Discrete Fourier Transforms can identify operational environments in an autonomous nonlinear system. Simulation results indicate the proposed method accurately identifies the environment and switches the correct FLC online to adapt the system's behavior.

Research paper thumbnail of Teaching hardware description languages to satisfy industry expectations

International Journal of Electrical Engineering Education, 2009

ABSTRACT

Research paper thumbnail of A tag-mediated game designed to study cooperation in human populations

2013 IEEE Conference on Computational Inteligence in Games (CIG), 2013

ABSTRACT How and why cooperation develops in human populations is not known. The iterated prisone... more ABSTRACT How and why cooperation develops in human populations is not known. The iterated prisoner's dilemma game provides a natural framework for studying cooperation growth in human populations. However, recent experiments with human subjects has exposed a number of serious flaws in virtually all of the game-theoretical models that have appeared in the literature. Indeed, some experiments suggest network reciprocity-thought to be essential for cooperation in human populationsmay actually play no role whatsoever. In this paper we briefly review some human experiments that were conducted in the last three years. We then present preliminary results of a new tag-mediated model designed for studying cooperation in human populations. The model exhibits many characteristics found in the human experiments including assortment, which many researchers now believe is necessary for maintaining cooperation.

Research paper thumbnail of On the value of operator-induced neighborhoods in fitness landscapes

2011 IEEE Congress of Evolutionary Computation (CEC), 2011

ABSTRACT All of the solutions to a combinatorial optimization problem can be collected into a fit... more ABSTRACT All of the solutions to a combinatorial optimization problem can be collected into a fitness landscape. Often these landscapes are huge, making an exhaustive search for the best solution impractical. Stochastic search algorithms work best if the search operators are tailored to the fitness landscape structure. Some researchers claim this structure is induced by the search operator itself. In this paper we show structural information obtained from operator-induced neighborhoods can be completely misleading unless specific ordering has prevailed during the mapping process and appropriate isomorphic proofs have been made.

Research paper thumbnail of Fault Recovery Using Evolvable Fuzzy Systems

2007 IEEE Workshop on Evolvable and Adaptive Hardware (WEAH2007), 2007

Autonomous systems must survive for long periods without relying on humans for fault recovery. Fa... more Autonomous systems must survive for long periods without relying on humans for fault recovery. Faults may be impossible to analyze remotely and redundant hardware is frequently not allowed. The only recourse may be to replace the existing control strategy. This paper proposes a fuzzy logic controller architecture that executes a replacement control strategy for autonomous systems. This paper shows this architecture is ideally suited for fault recovery in autonomous systems with imprecisely defined faults. The controller is evolved in-situ and evaluated intrinsically

Research paper thumbnail of Using ant colony optimization to find low energy atomic cluster structures

2005 Ieee Congress on Evolutionary Computation, Oct 2, 2005

Over the past 20 years atomic cluster structures have been intensively studied because of their i... more Over the past 20 years atomic cluster structures have been intensively studied because of their importance in physics, chemistry and recently material science. Unfortunately finding the lowest energy structure, which is the most stable configuration, is NP-hard. In this paper we present preliminary results on an ant colony optimization algorithm used in conjunction with a Monte Carlo sampling method to find low energy configurations of small silicon atomic clusters.

Research paper thumbnail of An Evolutionary Approach to Hardware/Software Partitioning

In this paper, we present an approach to hardware software codesign of real-time embedded systems... more In this paper, we present an approach to hardware software codesign of real-time embedded systems. Two of the di culties associated with codesign are handling tradeo s among multiple attributes and exploring a large design space. We use a combination of techniques from the evolutionary computation and utility theory elds to address these problem areas. A real-time microcontroller-based design example is presented to illustrate our approach.

Research paper thumbnail of Characterization of attractors in speech signals

Biosystems, Feb 1, 1997

It is shown that speech signals can have attractors with fractal dimension. A method for estimati... more It is shown that speech signals can have attractors with fractal dimension. A method for estimating this dimension is given. The existence of this attractor suggests that statistical models for speech may be inappropriate. Moreover, the dimension of this attractor is a lower bound on the order of a linear prediction model. © 1997 Elsevier Science Ireland Ltd.