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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Self-Scaling Evolution of Analog Computation Circuits

Pyle, Steven 01 January 2015 (has links)
Energy and performance improvements of continuous-time analog-based computation for selected applications offer an avenue to continue improving the computational ability of tomorrow*s electronic devices at current technology scaling limits. However, analog computation is plagued by the difficulty of designing complex computational circuits, programmability, as well as the inherent lack of accuracy and precision when compared to digital implementations. In this thesis, evolutionary algorithm-based techniques are utilized within a reconfigurable analog fabric to realize an automated method of designing analog-based computational circuits while adapting the functional range to improve performance. A Self-Scaling Genetic Algorithm is proposed to adapt solutions to computationally-tractable ranges in hardware-constrained analog reconfigurable fabrics. It operates by utilizing a Particle Swarm Optimization (PSO) algorithm that operates synergistically with a Genetic Algorithm (GA) to adaptively scale and translate the functional range of computational circuits composed of high-level or low-level Computational Analog Elements to improve performance and realize functionality otherwise unobtainable on the intrinsic platform. The technique is demonstrated by evolving square, square-root, cube, and cube-root analog computational circuits on the Cypress PSoC-5LP System-on-Chip. Results indicate that the Self-Scaling Genetic Algorithm improves our error metric on average 7.18-fold, up to 12.92-fold for computational circuits that produce outputs beyond device range. Results were also favorable compared to previous works, which utilized extrinsic evolution of circuits with much greater complexity than was possible on the PSoC-5LP.
2

Morphogenetic evolvable hardware

Lee, Justin Alexander January 2006 (has links)
Evolvable hardware (EHW) uses simulated evolution to generate an electronic circuit with specific characteristics, and is generally implemented on Field Programmable Gate Arrays (FPGAs). EHW has proven to be successful at producing small novel circuits for applications such as robot control and image processing, however, traditional approaches, in which the FPGA configuration is directly encoded on the chromosome, have not scaled well with increases in problem and FPGA architecture complexity. One of the methods proposed to overcome this is the incorporation of a growth process, known as morphogenesis, into the evolutionary process. However, existing approaches have tended to abstract away the underlying architectural details, either to present a simpler virtual FPGA architecture, or a biochemical model that hides the relationship between the cellular state and the underlying hardware. By abstracting away the underlying architectural details, EHW has moved away from one of its key strengths, that being to allow evolution to discover novel solutions free of designer bias. Also, by separating the biological model from the target FPGA architecture, too many assumptions and arbitrary decisions need to be made, which are liable to lead to the growth process failing to produce the desired results. In this thesis a new approach to applying morphogenesis to gate-level FPGA- based EHW is presented, whereby circuit growth is closely tied to the underlying gate-level architecture, with circuit growth being driven largely by the state of gate-level resources of the FPGA. An investigation into the applicability of biological processes, structures and mechanisms to morphogenetic EHW (MGEHW) is conducted, and the resulting design elaborated. The developed MGEHW system is applied to solving a signal routing problem with irregular and severe constraints on routing resources. It is shown that the morphogenetic approach outperforms a traditional EHW approach using a direct encoding, and importantly, is able to scale to larger, more complex, signal routing problems without any significant increase in the number of generations required to find an optimal solution. With the success of the MGEHW system in solving primarily structural prob- lems, it is then applied to solving a combinatorial function problem, specifically a one-bit full adder, with a more complete set of FPGA resources. The results of these experiments, together with the previous experiments, has provided valuable information that when analysed has enabled the identification of the critical factors that determine the likelihood of an EHW problem being solvable. In particular this has highlighted the importance of effective fitness feedback for guiding evolution towards its desired goal. Results indicate that the gate-level morphogenetic approach is promising. The research presented here is far from complete; many avenues for future research have opened. The MGEHW system that has been developed allows further research in this area to be explored experimentally. Some of the most fruitful directions for future research are described.
3

Optimizing Dynamic Logic Realizations For Partial Reconfiguration Of Field Programmable Gate Arrays

Parris, Matthew 01 January 2008 (has links)
Many digital logic applications can take advantage of the reconfiguration capability of Field Programmable Gate Arrays (FPGAs) to dynamically patch design flaws, recover from faults, or time-multiplex between functions. Partial reconfiguration is the process by which a user modifies one or more modules residing on the FPGA device independently of the others. Partial Reconfiguration reduces the granularity of reconfiguration to be a set of columns or rectangular region of the device. Decreasing the granularity of reconfiguration results in reduced configuration filesizes and, thus, reduced configuration times. When compared to one bitstream of a non-partial reconfiguration implementation, smaller modules resulting in smaller bitstream filesizes allow an FPGA to implement many more hardware configurations with greater speed under similar storage requirements. To realize the benefits of partial reconfiguration in a wider range of applications, this thesis begins with a survey of FPGA fault-handling methods, which are compared using performance-based metrics. Performance analysis of the Genetic Algorithm (GA) Offline Recovery method is investigated and candidate solutions provided by the GA are partitioned by age to improve its efficiency. Parameters of this aging technique are optimized to increase the occurrence rate of complete repairs. Continuing the discussion of partial reconfiguration, the thesis develops a case-study application that implements one partial reconfiguration module to demonstrate the functionality and benefits of time multiplexing and reveal the improved efficiencies of the latest large-capacity FPGA architectures. The number of active partial reconfiguration modules implemented on a single FPGA device is increased from one to eight to implement a dynamic video-processing architecture for Discrete Cosine Transform and Motion Estimation functions to demonstrate a 55-fold reduction in bitstream storage requirements thus improving partial reconfiguration capability.
4

Sustainable Fault-handling Of Reconfigurable Logic Using Throughput-driven Assessment

Sharma, Carthik 01 January 2008 (has links)
A sustainable Evolvable Hardware (EH) system is developed for SRAM-based reconfigurable Field Programmable Gate Arrays (FPGAs) using outlier detection and group testing-based assessment principles. The fault diagnosis methods presented herein leverage throughput-driven, relative fitness assessment to maintain resource viability autonomously. Group testing-based techniques are developed for adaptive input-driven fault isolation in FPGAs, without the need for exhaustive testing or coding-based evaluation. The techniques maintain the device operational, and when possible generate validated outputs throughout the repair process. Adaptive fault isolation methods based on discrepancy-enabled pair-wise comparisons are developed. By observing the discrepancy characteristics of multiple Concurrent Error Detection (CED) configurations, a method for robust detection of faults is developed based on pairwise parallel evaluation using Discrepancy Mirror logic. The results from the analytical FPGA model are demonstrated via a self-healing, self-organizing evolvable hardware system. Reconfigurability of the SRAM-based FPGA is leveraged to identify logic resource faults which are successively excluded by group testing using alternate device configurations. This simplifies the system architect's role to definition of functionality using a high-level Hardware Description Language (HDL) and system-level performance versus availability operating point. System availability, throughput, and mean time to isolate faults are monitored and maintained using an Observer-Controller model. Results are demonstrated using a Data Encryption Standard (DES) core that occupies approximately 305 FPGA slices on a Xilinx Virtex-II Pro FPGA. With a single simulated stuck-at-fault, the system identifies a completely validated replacement configuration within three to five positive tests. The approach demonstrates a readily-implemented yet robust organic hardware application framework featuring a high degree of autonomous self-control.
5

An Analog Evolvable Hardware Device for Active Control

Vigraham, Saranyan A. 28 November 2007 (has links)
No description available.
6

Evolution and Analysis of Neuromorphic Flapping-Wing Flight Controllers

Boddhu, Sanjay Kumar 26 March 2010 (has links)
No description available.
7

Rychlá detekce aplikačních protokolů / Fast Detection of Application Protocols

Grochol, David January 2014 (has links)
Master thesis is focused on classification of application protocols based on application data taken from layer L7 of ISO/OSI model. The aim of the thesis is to suggest a classifier for SDM system (Software defined monitoring) so it could be used for links with throughput up to 100 Gb/s. At the same time it should classify with the fewest possible errors.Designed classifier consists of two parts. First part depicts encoders for encoding selected attributes. Second part deals with evaluating circuit which detects series characteristic for particular application protocols on the output from the first part. Considered attributes and series are taken from statistic analyzes of application protocol data.The classifier itself is designed so it can be implemented in FPGA and enables modification set of application protocols who intended for classification. The quality of  designed classifier is tested on real network data. The results of classification are compared with current methods used for classification of application protocols.
8

Genetic Algorithm Based Design and Optimization of VLSI ASICs and Reconfigurable Hardware

Fernando, Pradeep Ruben 17 October 2008 (has links)
Rapid advances in integration technology have tremendously increased the design complexity of very large scale integrated (VLSI) circuits, necessitating robust optimization techniques in many stages of VLSI design. A genetic algorithm (GA) is a stochastic optimization technique that uses principles derived from the evolutionary process in nature. In this work, genetic algorithms are used to alleviate the hardware design process of VLSI application specific integrated circuits (ASICs) and reconfigurable hardware. VLSI ASIC design suffers from high design complexity and a large number of optimization objectives requiring hierarchical design approaches and multi-objective optimization techniques. The floorplanning stage of the design cycle becomes highly important in hierarchical design methods. In this work, a multi-objective genetic algorithm based floorplanner has been developed with novel crossover operators to address the multi-objective floorplanning problem for VLSI ASICs. The genetic floorplanner achieves significant wirelength savings (>19% on average) with little or no increase in area ( < 3% penalty) over previous floorplanners that perform simultaneous area and wirelength minimization. Hardware implementation of genetic algorithms is gaining importance because of their proven effectiveness as optimization engines for real-time applications. Earlier hardware implementations suffer from major drawbacks such as absence of GA parameter programmability, rigid pre-defined system architecture, and lack of support for multiple fitness functions. A compact IP core that implements a general purpose GA engine has been designed to realize evolvable hardware in field programmable gate array devices. The designed GA core achieved a speedup of around 5.16x over an analogous software implementation. Novel reconfigurable analog architectures have been proposed to realize extreme environment analog electronics. In this work, a digital framework has been developed to realize self reconfigurable analog arrays (SRAA) where genetic algorithms are used to evolve the required analog functionality and compensate performance degradation in extreme environments. The framework supports two methods of compensation, namely, model based lookup and genetic algorithm based compensation and is scalable in terms of the number of fitness evaluation modules. The entire framework has been implemented as a digital ASIC in a leading industrystrength silicon-on-insulator (SOI) technology to obtain high performance and a small form factor.
9

Cascaded Digital Refinement for Intrinsic Evolvable Hardware

Thangavel, Vignesh 01 January 2015 (has links)
Intrinsic evolution of reconfigurable hardware is sought to solve computational problems using the intrinsic processing behavior of System-on-Chip (SoC) platforms. SoC devices combine capabilities of analog and digital embedded components within a reconfigurable fabric under software control. A new technique is developed for these fabrics that leverages the digital resources' enhanced accuracy and signal refinement capability to improve circuit performance of the analog resources' which are providing low power processing and high computation rates. In particular, Differential Digital Correction (DDC) is developed utilizing an error metric computed from the evolved analog circuit to reconfigure the digital fabric thereby enhancing precision of analog computations. The approach developed herein, Cascaded Digital Refinement (CaDR), explores a multi-level strategy of utilizing DDC for refining intrinsic evolution of analog computational circuits to construct building blocks, known as Constituent Functional Blocks (CFBs). The CFBs are developed in a cascaded sequence followed by digital evolution of higher-level control of these CFBs to build the final solution for the larger circuit at-hand. One such platform, Cypress PSoC-5LP was utilized to realize solutions to ordinary differential equations by first evolving various powers of the independent variable followed by that of their combinations to emulate mathematical series-based solutions for the desired range of values. This is shown to enhance accuracy and precision while incurring lower computational energy and time overheads. The fitness function for each CFB being evolved is different from the fitness function that is defined for the overall problem.
10

Uma ferramenta alternativa para síntese de circuitos lógicos usando a técnica de circuito evolutivo /

Goulart Sobrinho, Edilton Furquim. January 2007 (has links)
Orientador: Suely Cunha Amaro Mantovani / Banca: José Raimundo de Oliveira / Banca: Nobuo Oki / Resumo: Neste trabalho descreve-se uma metodologia para síntese e otimização de circuitos digitais, usando a teoria de algoritmos evolutivos e como plataforma os dispositivos reconfiguráveis, denominada Hardware Evolutivo do inglês- Evolvable Hardware - EHW. O EHW, tornou-se viável com o desenvolvimento em grande escala dos dispositivos reconfiguráveis, Programmable Logic Devices (PLD’s), cuja arquitetura e função podem ser determinadas por programação. Cada circuito pode ser representado como um indivíduo em um processo evolucionário, evoluindo-o através de operações genéticas para um resultado desejado. Como algoritmo evolutivo, aplicou-se o Algoritmo Genético (AG), uma das técnicas da computação evolutiva que utiliza os conceitos da genética e seleção natural. O processo de síntese aplicado neste trabalho, inicia por uma descrição do comportamento do circuito, através de uma tabela verdade para circuitos combinacionais e a tabela de estados para os circuitos seqüenciais. A técnica aplicada busca o arranjo correto e minimizado do circuito que desempenhe uma função proposta. Com base nesta metodologia, são implementados alguns exemplos em duas diferentes representações (mapas de fusíveis e matriz de portas lógicas). / Abstract: In this work was described a methodology for optimization and synthesis of digital circuits, which consist of evolving circuits through evolvable algorithms using as platforms reconfigurable devices, denominated Evolvable Hardware (EHW). It was became viable with the large scale development of reconfigurable devices, whose architecture and function can be determined by programming. Each circuit can be represented as an individual within an evolutionary process, evolving through genetic operations to desire results. Genetic Algorithm (GA) was applied as evolutionary algorithm where this technique evolvable computation as concepts of genetics and natural selection. The synthesis process applied in this work starts from a description from the circuits behavior. Trust table for combinatorial circuits and state transition table for sequential circuits were used for synthesis process. This technic applied search the correct arrange and minimized circuit which response the propose function. Based on this methodology, some examples are implemented in two different representations (fuse maps and logic gate matrices). / Mestre

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