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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.
61

Associative neural networks: properties, learning, and applications.

January 1994 (has links)
by Chi-sing Leung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 236-244). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background of Associative Neural Networks --- p.1 / Chapter 1.2 --- A Distributed Encoding Model: Bidirectional Associative Memory --- p.3 / Chapter 1.3 --- A Direct Encoding Model: Kohonen Map --- p.6 / Chapter 1.4 --- Scope and Organization --- p.9 / Chapter 1.5 --- Summary of Publications --- p.13 / Chapter I --- Bidirectional Associative Memory: Statistical Proper- ties and Learning --- p.17 / Chapter 2 --- Introduction to Bidirectional Associative Memory --- p.18 / Chapter 2.1 --- Bidirectional Associative Memory and its Encoding Method --- p.18 / Chapter 2.2 --- Recall Process of BAM --- p.20 / Chapter 2.3 --- Stability of BAM --- p.22 / Chapter 2.4 --- Memory Capacity of BAM --- p.24 / Chapter 2.5 --- Error Correction Capability of BAM --- p.28 / Chapter 2.6 --- Chapter Summary --- p.29 / Chapter 3 --- Memory Capacity and Statistical Dynamics of First Order BAM --- p.31 / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Existence of Energy Barrier --- p.34 / Chapter 3.3 --- Memory Capacity from Energy Barrier --- p.44 / Chapter 3.4 --- Confidence Dynamics --- p.49 / Chapter 3.5 --- Numerical Results from the Dynamics --- p.63 / Chapter 3.6 --- Chapter Summary --- p.68 / Chapter 4 --- Stability and Statistical Dynamics of Second order BAM --- p.70 / Chapter 4.1 --- Introduction --- p.70 / Chapter 4.2 --- Second order BAM and its Stability --- p.71 / Chapter 4.3 --- Confidence Dynamics of Second Order BAM --- p.75 / Chapter 4.4 --- Numerical Results --- p.82 / Chapter 4.5 --- Extension to higher order BAM --- p.90 / Chapter 4.6 --- Verification of the conditions of Newman's Lemma --- p.94 / Chapter 4.7 --- Chapter Summary --- p.95 / Chapter 5 --- Enhancement of BAM --- p.97 / Chapter 5.1 --- Background --- p.97 / Chapter 5.2 --- Review on Modifications of BAM --- p.101 / Chapter 5.2.1 --- Change of the encoding method --- p.101 / Chapter 5.2.2 --- Change of the topology --- p.105 / Chapter 5.3 --- Householder Encoding Algorithm --- p.107 / Chapter 5.3.1 --- Construction from Householder Transforms --- p.107 / Chapter 5.3.2 --- Construction from iterative method --- p.109 / Chapter 5.3.3 --- Remarks on HCA --- p.111 / Chapter 5.4 --- Enhanced Householder Encoding Algorithm --- p.112 / Chapter 5.4.1 --- Construction of EHCA --- p.112 / Chapter 5.4.2 --- Remarks on EHCA --- p.114 / Chapter 5.5 --- Bidirectional Learning --- p.115 / Chapter 5.5.1 --- Construction of BL --- p.115 / Chapter 5.5.2 --- The Convergence of BL and the memory capacity of BL --- p.116 / Chapter 5.5.3 --- Remarks on BL --- p.120 / Chapter 5.6 --- Adaptive Ho-Kashyap Bidirectional Learning --- p.121 / Chapter 5.6.1 --- Construction of AHKBL --- p.121 / Chapter 5.6.2 --- Convergent Conditions for AHKBL --- p.124 / Chapter 5.6.3 --- Remarks on AHKBL --- p.125 / Chapter 5.7 --- Computer Simulations --- p.126 / Chapter 5.7.1 --- Memory Capacity --- p.126 / Chapter 5.7.2 --- Error Correction Capability --- p.130 / Chapter 5.7.3 --- Learning Speed --- p.157 / Chapter 5.8 --- Chapter Summary --- p.158 / Chapter 6 --- BAM under Forgetting Learning --- p.160 / Chapter 6.1 --- Introduction --- p.160 / Chapter 6.2 --- Properties of Forgetting Learning --- p.162 / Chapter 6.3 --- Computer Simulations --- p.168 / Chapter 6.4 --- Chapter Summary --- p.168 / Chapter II --- Kohonen Map: Applications in Data compression and Communications --- p.170 / Chapter 7 --- Introduction to Vector Quantization and Kohonen Map --- p.171 / Chapter 7.1 --- Background on Vector quantization --- p.171 / Chapter 7.2 --- Introduction to LBG algorithm --- p.173 / Chapter 7.3 --- Introduction to Kohonen Map --- p.174 / Chapter 7.4 --- Chapter Summary --- p.179 / Chapter 8 --- Applications of Kohonen Map in Data Compression and Communi- cations --- p.181 / Chapter 8.1 --- Use Kohonen Map to design Trellis Coded Vector Quantizer --- p.182 / Chapter 8.1.1 --- Trellis Coded Vector Quantizer --- p.182 / Chapter 8.1.2 --- Trellis Coded Kohonen Map --- p.188 / Chapter 8.1.3 --- Computer Simulations --- p.191 / Chapter 8.2 --- Kohonen MapiCombined Vector Quantization and Modulation --- p.195 / Chapter 8.2.1 --- Impulsive Noise in the received data --- p.195 / Chapter 8.2.2 --- Combined Kohonen Map and Modulation --- p.198 / Chapter 8.2.3 --- Computer Simulations --- p.200 / Chapter 8.3 --- Error Control Scheme for the Transmission of Vector Quantized Data --- p.213 / Chapter 8.3.1 --- Motivation and Background --- p.214 / Chapter 8.3.2 --- Trellis Coded Modulation --- p.216 / Chapter 8.3.3 --- "Combined Vector Quantization, Error Control, and Modulation" --- p.220 / Chapter 8.3.4 --- Computer Simulations --- p.223 / Chapter 8.4 --- Chapter Summary --- p.226 / Chapter 9 --- Conclusion --- p.232 / Bibliography --- p.236
62

The role of prediction error in probabilistic associative learning

Cevora, Jiri January 2018 (has links)
This thesis focuses on probabilistic associative learning. One of the classic effects in this field is the stimulus associability effect for which I derive a statistically optimal inference model and a corresponding approximation that addresses a number of problems with the original account of Mackintosh. My proposed account of associability - a variable learning rate depending on a relative informativeness of stimuli - also accounts of the classic blocking effect \cite{kamin1969predictability} without the need for Prediction Error [PE] computation. Given that blocking was the main impetus for placing PE at the centre of learning theories, I critically re-evaluate other evidence for PE in learning, particularly the recent neuroimaging evidence. I conclude that the brain data are not as clear cut as often presumed. The main shortcoming of the evidence implicating PE in learning is that probabilistic associative learning is mostly described as a transition from one state of belief to another, yet those beliefs are typically observed only after multiple learning episodes and in a very coarse manner. To address this problem, I develop an experimental paradigm and accompanying statistical methods that allow one to infer the beliefs at any given point in time. However, even with the rich data provided by this new paradigm, the blocking effect still cannot provide conclusive evidence for the role of PE in learning. I solve this problem by deriving a novel conceptualisation of learning as a flow in probability space. This allows me to derive two novel effects that can unambiguously distinguish learning that is driven by PE from learning not driven by PE. I call these effectsgeneralized blocking and false blocking, given their inspiration by the original paradigm of Kamin (1969). These two effects can be generalized to the entirety of probability space, rather than just the two specific points provided by the paradigms used by Mackintosh and Kamin, and therefore offer greater sensitivity to differences in learning mechanisms. In particular, I demonstrate that these effects are necessary consequences of PE-driven learning, but not learning based on the relative informativeness of stimuli. Lastly I develop an online experiment to acquire data on the new paradigm from a large number (approximately 2000) of participants recruited via social media. The results of model fitting, together with statistical tests of generalized blocking and false blocking, provide strong evidence against a PE-driven account of learning, instead favouring the relative informativeness account derived at the start of the thesis.
63

An integrated approach to parametric associative design for powertrain components on the automotive industry

Salehi-Douzloo, Vahid January 2012 (has links)
The automotive engineering process is characterized by a long and complex design process which starts with the first sketches in the preliminary design phase and proceeds to the final detailed CAD and physical models. In this process, every design phase includes different process steps and tasks which are closely interconnected with each other. Therefore the different design stages demand capable Computer Aided Design (CAD) systems which are able to handle the different kinds of design information created and manipulated in the process. Currently in automotive practice, parametric and associative (PA) CAD systems are widely applied in the product development process. Such systems allow design knowledge to be embedded in CAD models by means of rules and formulae. In addition, CAD parts and assemblies can be generated faster and easier by modification of design parameters and therefore there is a possibility to create different CAD model variants which are based on the same CAD model. The four key element of the following work are (a) to identify the problems during the design process with parametric and associative (PA) methods during a three year of study and also the analysis of the literature survey. Furthermore (b) in this study the author will develop and implement a newly developed PA design approach (PARAMASS) in a ―real‖ industrial context. Beside this the following work will (c) discuss the issues which are important during the implementation of the developed PA approach in an industrial surrounding. The last key element (d) is to develop an evaluation approach for the PARAMASS approach during the application in an industrial context. In this case the author will be able to do action research in the industry and get first hand information during the accomplishment of these key elements. This thesis presents the results of a research programme carried out using the design research methodology of Blessing and Chakrabarti, aimed at understanding the difficulties and challenges faced by designers in using PA CAD systems and then developing and evaluating an integrated approach to the creation of PA CAD models in an automotive power train design context. Firstly, this thesis presents a review of the state of the art in PA design methods and approaches and also reviews previous research on the development of methodologies for the construction of PA CAD models. It then presents results of a descriptive study of the use of PA CAD tools and methods in vehicle power train design in an automotive original equipment manufacturer and in companies in its supply chain using questionnaires, interviews, tests and other field studies with a number of practising engineers. This study identified a number of issues faced by designers in the use of PA CAD tools and allowed the requirements for improved methods for the use of PA CAD tools to be formulated and indicators identified for their evaluation. Based on the results of the descriptive study a new integrated parametric associative (PA) approach for the design process of power train components was created in a prescriptive study stage. The approach, called PARAMASS, allows designers to construct and modify models in a methodical way based on three main phases: a specification phase to prepare the relevant parameters and associative relationships, a structuring phase that allows part and assembly structures to be created and a modification phase in which the created parametric and associative information can be modified and changed. The method makes extensive use of predefined structures matrix approaches adapted from the Design Structure Matrix. The prescriptive study phase of the research was followed by a second descriptive study to evaluate and investigate in both a qualitative and quantitative way the changes achieved by the PARAMASS approach. The qualitative evaluation was based on the Goal Question Metric approach and showed that there are advantages related to the reusability aspects like learning, application and acceptance of the developed integrated approach. The quantitative evaluation was based on the Use Case approach and demonstrated good advantages in applying the developed approach, but dependent on the complexity of the created parts and assemblies.
64

Quand la puissance publique délègue l'égalité : ethnographie de la politique de développement du football féminin en France (2011 - 2017) / When public authorities delegate equality : ethnography of the development policy of women's football in France (2011 - 2017)

Martin, Camille 01 December 2017 (has links)
Le fonctionnement du secteur associatif ne peut être compris sans envisager le lien qu'il entretient aux pouvoirs publics et cette intrication entre secteurs public et privé non lucratif s’avère particulièrement structurante dans le domaine du sport. En effet, ces activités sont largement administrées par des structures associatives mais la reconnaissance de l'utilité publique est ancienne et invite à leur encadrement public. L'action publique dans le domaine du sport est alors largement déléguée aux associations et fédérations sportives, lesquelles se voient attribuer dans ce cadre des ressources matérielles, humaines et symboliques qui assurent le pouvoir de prescription de l'Etat sur leur fonctionnement. C'est dans un tel contente que je propose d'envisager la politique de féminisation du football engagée par la Fédération Française de Football comme une politique publique sectorielle en faveur de l'égalité entre les femmes et les hommes, déléguée par l’État. Ainsi, ce travail propose une réflexion sur les effets de la délégation de politiques publiques vers le secteur associatif, en réalisant un détour par l’observation du travail concret des salarié-e-s de droit privé à qui incombent ces missions de service public, pour rendre compte des rapports de domination dans lesquelles ils et elles se voient pris-e-s et qui constituent autant de contraintes sur leur activité. Cette démarche permet ainsi d'envisager conjointement les conséquences de cette délégation sur les modalités de réalisation de ces missions (les effets sur les usager-e-s) et sur le travail de celles et ceux à qui incombent leur définition et leur mise en œuvre (effet sur les prestataires, salarié-e-s et bénévoles). Cette présentation s'adosse ainsi à un travail ethnographique de plusieurs années au sein des instances gestionnaires de la FFF, lequel s'est construit en partie autour de ma participation aux activités fédérales. Après avoir proposé une évaluation quantitative des modalités de diffusion du football féminin depuis le début des années 1990, je montre qu’en dépit du caractère hautement ambigu de la position de salarié-e associatif-ve – contractuellement rémunéré-e-s dans des organisations structurées par une éthique de désintéressement – celles et ceux qui sont chargé-e-s de la mise en œuvre de la féminisation à la FFF construisent leur activité autour de la vocation de service public qui la justifie et orientent en conséquence le contenu de leur activité. J’envisage ensuite la manière dont les rapports de genre dans lesquels sont prises les salariées chargées du développement du football féminin informent les orientations qu’elles donnent aux dispositifs de diffusion de cette pratique, au gré d’un travail de naturalisation des dispositions féminines, et de qualification individualisée des rapports sociaux de sexe. Ainsi, c'est en articulant des questionnements propres à la sociologie du travail (associatif), du genre et de l'action publique qu'il s'est agi de proposer une réflexion sur les enjeux de la recomposition de l'action publique, au travers des effets sociaux de sa délégation au secteur associatif. / This doctoral research has begun after I joined a workgroup of the French Football Association – the Fédération Française de Football (FFF) – in October 2012. This workgroup was focused on how to develop female football. The reason I joined the group was initially to get access to administrative data to study the career of the players. I got this access in exchange of doing some statistical work for the group. Thus, I worked during four years, with four employees of the FFF, in charge of the development of female football. Doing so, I got the chance to observe the negotiations about gender equality in football and debates about the best orientation to give to the policy of development.This work precisely deals with the construction and implementation of this new policy, created in 2011. This policy takes place in the institutional context of a partnership between the ministry of sports and the sports associations. Thus, the policy of football feminization will be seen as a delegated sectorial policy for gender equality. This mechanism of policy delegation exists in the domain of sport since the 50’s. In other words, the policy of sports is partially operated by the sports associations. The ministry of sports provides them with funds and human support (nearly 1,600 civil servants work for the sport associations). Thus, the public authority keeps a control over the policy of sport and delegates its implementation. This delegation scheme is not specific to sport and has been used in various fields since the 80’s. It is reflected in the growing number of employees in the non-profit associations sector; this sector having increasingly a role of intermediate in the public policies.Therefore, the purpose will be to illustrate the impacts of delegating the public policy related to gender equality to employees working under private law for the FFF. Consequently, their working conditions, the social relationships in which they are included will be objectively examined, to grasp how they embodied this policy and they reflect it. In that matter, it will be demonstrated that despite the great ambiguity of the employee’s status in an association – contractually hired in an organization structured around an ethic of selflessness –, the ones in charge of implementing the feminization within the FFF, build their activity around public service values which consequently impacts the content of their activities. Subsequently, I will consider how the gender inequality, in which the female employees developing the female football evolve, influences the orientations that they give to the policy of development of female football. I will demonstrate that the marginal position occupied by the female employees in the FFF reduces not only their range of actions but creates the risk of a transfer of gender inequality from the female employees to the female players. Indeed, this work proposes to reflect on the impact of delegating public policies to non-profit associations thanks to an observation study of the actual work of privately hired employees to whom the responsibility of public policy is delegated. Hence, it will interlink questionings in sociology related to gender, associative work and public policy.
65

Neural network with multiple-valued activation function. / CUHK electronic theses & dissertations collection

January 1996 (has links)
by Chen, Zhong-Yu. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (p. 146-[154]). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.
66

Associative processing implemented with content-addressable memories

Kida, Luis Sergio 01 January 1991 (has links)
The associative processing model provides an alternative solution to the von Neumann bottleneck. The memory of an associative computer takes some of the responsibility for processing. Only intermediate results are exchanged between memory and processor. This greatly reduces the amount of communication between them. Content-addressable memories are one implementation of memory for this computational model. Associative computers implemented with CAMs have reported performance improvements of three orders of magnitude, which is equivalent to the performance of the same application running in a conventional computer with clock frequencies of the order of GHz. Among the benefits of content-addressable memories to the computer system are: 1) it is simpler to parallelize algorithms and implement concurrency; 2) the synchronization cost for parallel processing is lower, which enables the use of small grain parallelism; 3) it can improve the performance in non-numeric applications that are known to have low performance in conventional computers; 4) it provides a trade off between integration density and clock frequencies to achieve the same performance that is not available in RAM 5) matches well to current and future technologies due to the trade off between integration and clock frequency; 6) it attacks the von Neumann bottleneck by reducing the requirements on the communication bandwidth between processor and memory. In this thesis, the role of CAMs in associative processing is analyzed, reaching the conclusion that to implement these characteristics the CAM must be able to filter the data transferred to the processor, provide explicit support for parallelism and data structures, support non-numeric applications, and execute logical operations. The characteristics and architecture of a content-addressable memory integrated circuit are presented along with an application with estimated performance improvement of over three orders of magnitude.
67

Smart Memory: An Inexact Content-Addressable Memory

Lee, Jack 12 February 1993 (has links)
The function of a Content-Addressable Memory (CAM) is to efficiently search the information stored in the memory, by using hardware rather than software with a corresponding improvement in searching speed. This hardware allows a parallel search by matching the data stored in memory to a search key rather than sequentially searching address by address as is done in a Random Access Memory. Although existing CAMs are more efficient in finding relevant information than RAM, there are additional improvements that can be made to further improve its efficiency. For example, previous CAMs use a word parallel searching scheme that can only identify exact matches. To find the best (closest) match, previous CAMs had to use bit serial approaches. Although still more efficient than RAM searching, these CAMs were limited by the word size (bit width) of the memory. Responding to this inefficiency, the CAM described in this thesis improves best-fit searching by using analog design in combination with digital design. This design retains a mismatch line to collect the result of the comparison of each bit of a word which is decoded by a simple flash A/D. This means that after a single operation the best-fit plus all words with zero to three bits of mismatch, are determined. This word/bit parallel searching makes this CAM more efficient than existing CAMs. The best-fit function of this CAM is good for database retrieval, communications and error correction circuitry. By using the high speed searching and the inexact match feature, this CAM also provides efficient sorting and set operations. The accumulated searching time is shortened when compared to regular CAM and RAM. The inexact CAM in this thesis is designed using mixed analog/digital design in a 2~ CMOS technology.
68

Cofree objects in the categories of comonoids in certain abelian monoidal categories

Abdulwahid, Adnan Hashim 01 August 2016 (has links)
We investigate cofree coalgebras, and limits and colimits of coalgebras in some abelian monoidal categories of interest, such as bimodules over a ring, and modules and comodules over a bialgebra or Hopf algebra. We nd concrete generators for the categories of coalgebras in these monoidal categories, and explicitly construct cofree coalgebras, products and limits of coalgebras in each case. This answers an open question in [4] on the existence of a cofree coring, and constructs the cofree (co)module coalgebra on a B-(co)module, for a bialgebra B.
69

Prefrontal Cortex Circuitry in Sex Differences of Context-Mediated Renewal of Appetitive Pavlovian Conditioned Responding

Anderson, Lauren C. January 2017 (has links)
Thesis advisor: Gorica D. Petrovich / Learned associations are formed when cues from the environment are paired with biologically important events and can later drive appetitive and aversive behaviors. These behaviors can persist and reappear after extinction because the original learned associations continue to exist. In particular, cues previously associated with food can later stimulate appetite and food consumption in the absence of hunger. Renewal, or reinstatement, of extinguished conditioned behaviors may help explain the mechanisms underlying persistent responding to food cues and difficulty associated with changing unhealthy eating habits. The aim of this dissertation was to determine key components in the neural circuitry mediating renewal of responding to food cues. The main focus was on the ventromedial prefrontal cortex (vmPFC; includes the infralimbic (ILA) and prelimbic (PL) areas) because that region was selectively recruited during context-dependent renewal (Chapter 3). In all of the experiments, the behavior and neural substrates of male and female rats were compared. It was important to examine both males and females because sex differences in context-mediated renewal were recently established: males consistently show renewal responding while females fail to do so (Chapters 2 and 3). The first study in this dissertation examined whether behavioral sex differences were driven by estradiol (Chapter 2) and whether the vmPFC is recruited during renewal responding (Fos induction; Chapter 3). Then, to establish the vmPFC is causal in driving the behavioral responding during renewal in a sex-specific way (Chapter 4), the vmPFC was silenced in males and stimulated it in females. This was accomplished using a chemogenetic methodology, DREADDs (Designer Receptors Exclusively Activated by Designer Drugs). Inhibiting the vmPFC in males blocks renewal responding. Reversely, stimulating the vmPFC in females resulted in renewal of responding. To determine key components of the vmPFC circuitry mediating renewal and whether these were different in males and females the experiments in Chapter 5 examined activation of PL inputs using a retrograde tract tracing combined with Fos detection design. The pathways to the PL from the ventral hippocampal formation (subiculum and CA1), the thalamus (anterior paraventricular nucleus), and the amygdala (anterior basolateral nucleus) were recruited in males and not recruited in females. This lack of recruitment could explain the lack of behavioral responding during renewal for females. Taken together, there are distinct and sex-specific circuitries recruited during context-mediated renewal. The findings from these experiments advanced our understanding of the neural mechanisms underlying sex differences in associative memory and contextual processing. They are also important for our understanding of the resilience of food cue to influence our consumption and diet choices. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.
70

The Named-State Register File

Nuth, Peter R. 01 August 1993 (has links)
This thesis introduces the Named-State Register File, a fine-grain, fully-associative register file. The NSF allows fast context switching between concurrent threads as well as efficient sequential program performance. The NSF holds more live data than conventional register files, and requires less spill and reload traffic to switch between contexts. This thesis demonstrates an implementation of the Named-State Register File and estimates the access time and chip area required for different organizations. Architectural simulations of large sequential and parallel applications show that the NSF can reduce execution time by 9% to 17% compared to alternative register files.

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