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2010 International Conference on Reconfigurable Computing and FPGAs, ReConFig 2010

作者： Muñoz, Daniel M. Llanos, Carlos H. Dos S. Coelho, Leandro Ayala-Rincón, Mauricio Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia DF Brazil Industrial and Systems Engineering Graduate Program LAS/PPGPES Pontifical Catholic University of Parana Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia DF Brazil

ISBN: (纸本)9780769543147

Particle Swarm Optimization (PSO) algorithms have been proposed to solve engineering problems that require to find an optimal point of operation. However, the PSO algorithm suffers from premature convergence and high elapsed time when solving multimodal and large scale engineering problems. This problem becomes an evident drawback for embedded applications in which the microcontrollers often operates at low computational capacity. This paper proposes a hardware implementation of a parallel self-adaptive PSO algorithm based on an attractive-repulsive scheme and using the efficient floating-point arithmetic which performs computations with large dynamic range and high precision. The parallel capabilities of the PSO are exploited by implementing parallel particles directly in hardware in order to decrease the running time. In addition, the attractive-repulsive technique avoids the premature convergence problem by self-adapting the swarm behavior according to its diversity. Synthesis and simulation results for benchmark test problems were performed, demonstrating the correctness of the proposed architectures. Finally, an elapsed time comparison between the hardware and software implementations shows the suitableness of the proposed architecture for embedded applications. © 2010 IEEE.

关键词： Global optimization

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Cauchy particle swarm optimization with dynamic adaptation applied to inverse heat transfer problem

Cauchy particle swarm optimization with dynamic adaptation a...

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2010 IEEE International Conference on systems, Man and Cybernetics, SMC 2010

作者： Mariani, Viviana Cocco Neckel, Vagner Jorge Grebogi, Rafael Bartnik Dos Santos Coelho, Leandro Department of Mechanical Engineering PPGEM Pontifical Catholic University of Paraná Imaculada Conceição 1155 80215-901 Curitiba Paraná Brazil Industrial and Systems Engineering Graduate Program PPGEPS Pontifical Catholic University of Paraná Imaculada Conceição 1155 80215-901 Curitiba Paraná Brazil

ISBN: (纸本)9781424465880

The particle swarm optimization (PSO) algorithm is a member of the wide category of swarm intelligence methods for solving global optimization problems. Its basic idea is the simulation of simplified animal social behaviors such as fish schooling and bird flocking. PSO algorithms are attracting attentions in recent years, due to their ability of keeping good balance between convergence and diversity maintenance. Several attempts have been made to improve the performance of the original PSO algorithm. In this paper, a modified version of the original PSO based on Cauchy distribution and dynamic adaptation of inertia factor, named modified PSO (MPSO), is proposed. to estimate the unknown variables of an inverse heat transfer problem. To validate the optimization performance of the proposed MPSO, an inverse heat transfer problem is illustrated and the algorithm has to estimate its unknown variables. The results testify that the MPSO can perform well in an inverse heat transfer problem. ©2010 IEEE.

关键词： Heat transfer

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Accelerating the Shuffled Frog Leaping algorithm by parallel implementations in FPGAs

Accelerating the Shuffled Frog Leaping algorithm by parallel...

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2010 IEEE 5th International Conference on Bio-Inspired Computing: Theories and Applications, BIC-TA 2010

作者： Muñoz, Daniel M. Llanos, Carlos H. Dos S. Coelho, Leandro Ayala-Rincón, Mauricio Department of Mechanical Engineering Automation and Control Group/GRACG University of Brasilia Brasilia D.F. Brazil Industrial and Systems Engineering Graduate Program Pontifical Catholic University of Parana Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia D.F. Brazil

ISBN: (纸本)9781424464388

Meta-heuristics are efficient techniques for solving large scale optimization problems in which traditional mathematical techniques are impractical or provide sub-optimal solutions. The Shuffled Frog Leaping algorithm (SFLA) is a stochastic iterative method, bio-inspired on the memetic evolution of a group of frogs when seeking for food, which combines the social behavior-based of the particle swarm optimization technique (PSO) and the global information exchange of memetic algorithms. However, the SFLA algorithm suffers on large execution times, being this problem clearly evident when solving complex optimization problems for embedded applications. This drawback can be overcome by exploiting the parallel capabilities of the SFLA. This paper proposes a hardware parallel implementation of the SFLA algorithm (HPSFLA) using FPGAs (Field programmable gate Arrays) and the efficient floating-point arithmetic. The proposed architecture allows the SFLA to improve the functionality of the algorithm as well as to decrease the execution times by implementing parallel frogs and parallel memeplexes. Three well-known benchmark problems have been used to validate the implemented algorithm and simulation results demonstrate that the HPSFLA speeds-up by factors of 362, 727 and 211 a C-code implementation using an embedded microprocessor for the Sphere, Rastrigin and Rosenbrock benchmarks problems, respectively. Synthesis, simulation and execution time results demonstrate the effectiveness of the proposed HPSFLA architecture for embedded optimization systems. © 2010 IEEE.

关键词： Global optimization

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Effect of axial heat conduction and internal heat generation on the effectiveness of counter flow microchannel heat exchangers

Effect of axial heat conduction and internal heat generation...

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作者： Mathew, B. Hegab, H. College of Engineering and Science Louisiana Tech University Ruston LA 71272 United States Micro and Nano Systems Track College of Engineering and Science LA Tech. Ruston LA 71272 United States Mechanical Engineering Program College of Engineering and Science LA Tech. Ruston LA 71272 United States

ISBN: (纸本)9781600867453

The influence of axial heat conduction and internal heat generation (viscous dissipation) on the effectiveness of a counter flow microchannel heat exchanger is analyzed in this paper. The ends of the wall separating the hot and cold fluid are kept isothermal, i.e. non-adiabatic, thereby leading to thermal interaction between the heat exchanger and its surroundings. A thermal model of this particular heat exchanger consists of three one dimensional governing equations. This system of equations is solved using finite difference method. The hot and cold fluid effectiveness is found to depend on parameters such as NTU, axial heat conduction parameter, end wall temperatures and internal heat generation parameter. Increase in axial heat conduction parameter of a heat exchanger subjected internal heat generation can either increase or decrease the effectiveness of the fluids depending on the temperature of the end walls. The effect of internal heat generation in a counter flow microchannel heat exchanger with axial heat conduction is to always degrade and improve the effectiveness of the hot and cold fluid, respectively. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Heat exchangers

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Dynamics of fluid flow in a heated zig-zag square microchannel

Dynamics of fluid flow in a heated zig-zag square microchann...

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作者： Mathew, B. John, T.J. Hegab, H. College of Engineering and Science Louisiana Tech University Ruston LA 71272 United States Micro and Nano Systems Track College of Engineering and Science LA Tech. Ruston LA 71272 United States Mechanical Engineering Program College of Engineering and Science LA Tech. Ruston LA 71272 United States

ISBN: (纸本)9781600867453

This paper deals with the dynamics of flow in a zig-zag square microchannel subjected to uniform external heat flux (H2 thermal boundary condition). The heat transfer and fluid flow characteristics is studied using CoventorWare™. Numerical studies are performed using microchannels with hydraulic diameter ranging from 100 μm to 300 μm for Reynolds number between 25 and 500. The angle which each arm of the zig-azg microchannel makes with the axial direction is varied from between 10° and 30° with increments of 10°. The effect of number of turns in a repeating unit for a specific length of the microchannel is also investigated in this paper. The Nusselt number and Poiseuille number in a zig-zag microchannel is found to be totally different from that in a straight square microchannel of the same geometric dimensions. These two parameters are found to increase with increase in Re for zig-zag microchannels with fixed geometry. The individual effect of each of these parameters is to increase both Nusselt number and Poiseuille number for a specific Reynolds number. The enhancement is highest with increase in number of turns while it is the lowest with increase in hydraulic diameter. The enhancement in Nusselt number and Poiseuille number is explained using the flow profile in the microchannels. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Microchannels

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Micro channel heat sink with embedded pin-fin structures

Micro channel heat sink with embedded pin-fin structures

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作者： John, T.J. Mathew, B. Hegab, H. College of Engineering and Science Louisiana Tech University Ruston LA 71272 United States Micro and Nano Systems Track College of Engineering and Science LA Tech. Ruston LA 71272 United States Mechanical Engineering Program College of Engineering and Science LA Tech. Ruston LA 71272 United States

ISBN: (纸本)9781600867453

The dissipation of heat with the help of micro channel heat sink and micro pin-fin fin heat sink has been a topic of interest for many researchers over a decade. The comparison between these two heat sink and the advantage and disadvantages of one over the other has been studied by researchers. In this paper, the authors are trying to study the effect of introducing pin-fin structures inside the micro channel heat sink. A FOM term is introduced in the paper to evaluate the overall performance of the ordinary micro channel heat sink and the micro channel heat sink with pin-fin structures embedded in it. The effect of introducing different shapes of pin-fin structures inside the micro channel is also studied in the paper. The study results showed that there is a huge increase in the overall performance of the micro channel heat sink by introducing pin-fin structures inside the channel, but the study also showed that the effect of introducing different shapes of pin-fin structures inside the channel is negligible. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Fins (heat exchange)

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Parallel flow microchannel heat exchangers subjected to axial heat conduction and internal heat generation

Parallel flow microchannel heat exchangers subjected to axia...

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ISBN: (纸本)9781600867453

This paper studies the effect of axial heat conduction and internal heat generation (viscous dissipation) on the effectiveness of a parallel flow microchannel heat exchanger. The ends of the wall separating the fluids are maintained at constant temperatures. This leads to heat transfer between the heat exchanger and its surroundings. The thermal model developed in this paper consists of three governing equations;one for each of the fluids and one for the wall. This system of coupled equations is solved simultaneously using finite difference method. The effectiveness of the fluids is found to depend on NTU, axial heat conduction parameter, end wall temperatures and internal heat generation parameter. In the presence of just internal heat generation the effectiveness of the hot and cold fluid degrades and improves, respectively. For situations when the temperature of the end wall at the inlet side is greater than that at the outlet side, increase in axial heat conduction parameter of a heat exchanger subjected internal heat generation increases and decreases the effectiveness of the hot and cold fluid, respectively. The effect of internal heat generation in a parallel flow microchannel heat exchanger with axial heat conduction is to always degrade and improve the effectiveness of the hot and cold fluid, respectively. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

关键词： Heat exchangers

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Comparison between two FPGA implementations of the particle swarm optimization algorithm for high-performance embedded applications

Comparison between two FPGA implementations of the particle ...

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2010 IEEE 5th International Conference on Bio-Inspired Computing: Theories and Applications, BIC-TA 2010

作者： Muñoz, Daniel M. Llanos, Carlos H. Dos S. Coelho, Leandro Ayala-Rincón, Mauricio Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia D.F. Brazil Industrial and Systems Engineering Graduate Program LAS/PPGPES Pontifical Catholic University of Parana Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia D.F. Brazil

ISBN: (纸本)9781424464388

Particle Swarm Optimization (PSO) algorithms have been proposed to solve engineering problems that require to find an optimal point of operation. There are several embedded applications which requires to solve online optimization problems with a high performance. However, the PSO suffers on large execution times, and this fact becomes evident when using Reduced Instruction Set Computer (RISC) microprocessors in which the operational frequencies are low in comparison with the high operational frequencies of traditional personal computers (PCs). This paper compares two hardware implementations of the parallel PSO algorithm using an efficient floating-point arithmetic which perform computations with large dynamic range and high precision. The full-parallel and the partially-parallel PSO architectures allow the parallel capabilities of the PSO to be exploited in order to decrease the running time. Three well-known benchmark test functions have been used to validate the hardware architectures and a comparison in terms of cost in logic area, quality of the solution and performance is reported. In addition, a comparison of the execution time between the hardware and two C-code software implementations, based on a Intel Core Duo at 1.6GHz and a embedded Microblaze microprocessor at 50MHz, are presented. © 2010 IEEE.

关键词： Global optimization

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Help on SOS

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IEEE CONTROL systems MAGAZINE 2010年第4期30卷 18-23页

作者： [Anonymous] University of California at Berkeley (UCB) Mechanical Engineering Department United States California Institute of Technology United States Aerospace Engineering and Mechanics Department University of Minnesota United States Control Science and Dynamical Systems Program University of Minnesota United States

Andy Packard, an expert from University of California at Berkeley (UCB) mechanical engineering Department shares views on the use of sum-of-squares (SOS) methods to determine the region of attraction (ROA). SOS applies to polynomials in several real variables and a polynomial is a finite linear combination of monomials. The ROA can be visualized by simulating the system from many initial conditions and plotting the trajectories in a phase plane plot for systems with two or three states. SOS techniques can be used to perform nonlinear analyses, including computation of input/output gains, estimation of reachable sets, and computation of robustness margins. The approaches that apply to SOS methods includes the computational requirements that grow rapidly in the number of variables and polynomial degree, which roughly limits SOS-based analysis to systems with at most eight to ten states, one to two inputs, and polynomial vector fields of degree 3.

关键词： Polynomials

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The P3E2 project: The introduction, implementation and evaluation of engineering design integrated across the middle school curriculum

The P3E2 project: The introduction, implementation and evalu...

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2010 ASEE Annual Conference and Exposition

作者： Pizziconi, Vincent Haag, Susan Ganesh, Tirupalavanam Cozort, Lynn Krause, Stephen Tasooji, Amaneh Ramakrishna, B.L. Meldrum, Deirdre Lunt, Brian Valdez, Albert Yarbrough, Victoria Harrington Bioengineering Program Fulton School of Engineering Arizona State University United States Research and Evaluation for CRESMET Arizona State University United States Department of Engineering Education Arizona State University United States Department of Academic Operations School of Mechanical Aerospace Chemical and Materials Engineering Arkansas State University United States School of Materials Arizona State University United States Materials Program Fulton School of Engineering Arizona State University United States Center for Ecogenomics Biodesign Institute United States Ira A. Fulton Schools of Engineering Arizona State University United States Harrington Bioengineering Program School of Biological and Health Systems Engineering Arizona State University United States

The Partnership, Pathway, and Pipeline for engineering Education (P 3E2) Project is an exploratory collaboration between ASU engineering faculty and Santan Junior High School teachers from a broad range of subjects and local community members aimed at engaging middle school students in real world and grade-relevant engineering activities as a way of enriching the value of their STEM education as it relates to STEM careers and their broad societal relevance. Central to the P3E2 project is the introduction of engineering design across the curricula via the implementation of the engineering design process through engineering service-learning projects that are intended to facilitate integrated learning of science, math, social studies and language arts. Such STEM-based integrated activities have been co-developed in partnership with middle school teachers and are designed to engage students and captivate their interest while promoting problem-solving and entrepreneurial skills by addressing real world needs in their local communities. This one-year pilot project consisted of four key phases that were implemented in nearly equal quarters, i.e., (a) the creation of a vibrant partnership to assess, motivate and inform teachers and counselors about engineering and its societal connections, workforce barriers, and curricular relevance, (b) the development of a viable education pathway to successfully engage 8th grade students in the full spectra of STEM-based learning that captivate their interest through integrated activities that span across science, mathematics, language arts and social studies, (c) the implementation of semester-long science and engineering fair projects chosen by students who were mentored by ASU engineering undergraduate and graduate students and (d) the evaluation of the P3E2 program effectiveness using designated assessment tools that were developed and administered to the teachers and students at the middle school. The major findings and the lessons

关键词： Students

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