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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.
391

Metamodeling Driven IP Reuse for System-on-chip Integration and Microprocessor Design

Mathaikutty, Deepak Abraham 02 December 2007 (has links)
This dissertation addresses two important problems in reusing intellectual properties (IPs) in the form of reusable design or verification components. The first problem is associated with fast and effective integration of reusable design components into a System-on-chip (SoC), so faster design turn-around time can be achieved, leading to faster time-to-market. The second problem has the same goals of faster product design cycle, but emphasizes on verification model reuse, rather than design component reuse. It specifically addresses reuse of reusable verification IPs to enable a "write once, use many times" verification strategy. This dissertation is accordingly divided into part I and part II which are related but describe the two problems and our solutions to them. These two related but distinctive problems faced by system design companies have been tackled through a unique approach which hither-to-fore only have been used in the software engineering domain. This approach is called metamodeling, which allows creating customized meta-language to describe the syntax and semantics for a modeling domain. It provides a way to create, transform and analyze domain specific languages, which are themselves described by metamodels, and the transformation and processing of models in such languages are also described by metamodels. This makes machine based interpretation and translation from these models an easier and formal task. In part I, we consider the problem of rapid system-level model integration of existing reusable components such that (i) the required architecture of the SoC can be expressed formally, (ii) automatic selection of components from an IP library to match the need of the system being integrated can be done, (iii) integrability of the components is provable, or checkable automatically, and (iv) structural and behavioral type systems for each component can be utilized through inferencing and matching techniques to ensure their compatibility. Our solutions include a component composition language, algorithms for component selection, type matching and inferencing algorithms, temporal property based behavioral typing, and finally a software system on top of an existing metamodeling environment. In part II, we use the same metamodeling environment to create a framework for modeling generative verification IPs. Our main contributions relate to INTEL's microprocessor verification environment, and our solution spans various abstraction levels (System, architectural, and microarchitecture) to perform verification. We provide a unified language that can be used to model verification IPs at all abstraction levels, and verification collaterals such as testbenches, simulators, and coverage monitors can be generated from these models, thereby enhancing reuse in verification. / Ph. D.
392

Harnessing the opportunities and overcoming constraints to widespread adoption of cage aquaculture in Ghana

Anane-Taabeah, Gifty 04 June 2012 (has links)
Understanding cage aquaculture adoption decisions and factors affecting adoption is necessary to ensure that fish production from cage aquaculture in Ghana is both significant and sustainable. The goal of this study was to provide a framework for understanding cage aquaculture adoption decisions and to identify factors affecting adoption, to inform decision makers as they formulate policies aimed at promoting cage aquaculture adoption in Ghana. I surveyed 122 respondents comprising current cage fish farmers, farmers who have abandoned cage aquaculture, and potential adopters of cage aquaculture such as, fish traders, fishermen and land-based fish farmers. Respondents answered questions related to knowledge, interest, constraints in cage aquaculture, and demographics. I used non-metric multidimensional scaling and discriminant function analysis to identify unique groups within the respondents, classify respondents according to their position in the innovation-decision continuum, and identify factors affecting cage aquaculture adoption. Based on their differences in knowledge and interests, I placed respondents into one of three stages of the cage aquaculture innovation-decision process model I developed: (1) Unawareness, (2) Knowledge, Persuasion, and Decision (KPD), and (3) Implementation (Confirmation and Abandonment). Respondents in the KPD and Implementation stages had knowledge, were more interested in cage aquaculture, and were aware of constraints in cage aquaculture, whereas respondents in the Unawareness stage lacked knowledge and interest in cage aquaculture, and did not clearly understand the constraints. Respondents who were males, belonged to the tribes Ewe and Akan, and who had fishing experience tended to be more interested in cage aquaculture. The lack of capital, high input costs, inability to adequately market fish, theft, lack of information sources, conflict over water use, and cage destruction by storms, were identified as the main constraints to cage aquaculture adoption in Ghana. The results of the study suggest that programs aimed at encouraging new entrants into cage aquaculture should focus on demographic characteristics such as gender, and tribe. However, demographic characteristics may affect adoption decisions and it may be important to consider them as such. Some recommendation to address the major constraints in cage aquaculture include: the Fisheries Directorate should (1) develop an efficient extension program that farmers can access regularly, especially, for farmers with no other information sources, (2) provide feed subsidy to enable farmers produce fish at competitive prices, (3) facilitate the formation of fish farmers' cooperative groups that would purchase large quantities of feed, (4) encourage local production of high quality fish feed, and (5) develop credit facilities that can be accessed by individuals interested in cage aquaculture to assist potential farmers who would, otherwise, not be able to adopt cage aquaculture . In addition, fish farmers should (6) be proactive in marketing their fish by identifying potential niche markets prior to production, and (7) join cooperative groups to ease the burden of accessing loans to increase production. / Master of Science
393

Analysis and Reduction of ComputerPerformance Metric Collection forPredictive Analysis : A study of computer performance metrics predictive capabilities within acloud data center.

Gashi, Alban January 2024 (has links)
This study, conducted in collaboration with Ericsson Research, explores the potential of utilizing metric data for predictive analytics within IT operations. The primary objective is to address underutilized data by investigating its utility in forecasting future trends and behaviors. The research is driven by two key questions: to what extent can metric data inform predictive behaviors and the identification of specific metrics most valuable for predictive analysis? The study focuses on three main aims: evaluating the quality and predictive suitability of Zabbix-collected data, assessing the strength of correlations within the datasets using industry-standard analytical techniques, and developing an inference model based on identified metrics. Initial findings indicate that while the metric data holds significant potential for predictive analytics, it exhibits high individuality among hosts, requiring careful feature selection and temporal resolution analysis. This research lays the ground-work for future studies to utilze datasets at Ericsson Research.
394

Semi-lipschitz functions, best approximation, and fuzzy quasi-metric hyperspaces

Sánchez Álvarez, José Manuel 25 June 2009 (has links)
En los últimos años se ha desarrollado una teoría matemática que permite generalizar algunas teorías matemáticas clásicas: hiperespacios, espacios de funciones, topología algebraica, etc. Este hecho viene motivado, en parte, por ciertos problemas de análisis funcional, concentración de medidas, sistemas dinámicos, teoría de las ciencias de la computación, matemática económica, etc. Esta tesis doctoral está dedicada al estudio de algunas de estas generalizaciones desde un punto de vista no simétrico. En la primera parte, estudiamos el conjunto de funciones semi-Lipschitz; mostramos que este conjunto admite una estructura de cono normado. Estudiaremos diversos tipos de completitud (bicompletitud, right k-completitud, D-completitud, etc), y también analizaremos cuando la casi-distancia correspondiente es balanceada. Además presentamos un modelo adecuado para el computo de la complejidad de ciertos algoritmos mediante el uso de normas relativas. Esto se consigue seleccionando un espacio de funciones semi-Lipschitz apropiado. Por otra parte, mostraremos que estos espacios proporcionan un contexto adecuado en el que caracterizar los puntos de mejor aproximación en espacios casi-métricos. El hecho de que varias hipertopologías hayan sido aplicadas con éxito en diversas áreas de Ciencias de la Computación ha contribuido a un considerable aumento del interés en el estudio de los hiperespacios desde un punto de vista no simétrico. Así, en la segunda parte de la tesis, estudiamos algunas condiciones de mejor aproximación en el contexto de hiperespacios casi-métricos. Por otro lado, caracterizamos la completitud de un espacio uniforme usando la completitud de Sieber-Pervin, la de Smyth y la D-completitud de su casi-uniformidad superior de Hausdorff-Bourbaki, definida en los subconjuntos compactos no vacíos. Finalmente, introducimos dos nociones de hiperespacio casi-métrico fuzzy. / Sánchez Álvarez, JM. (2009). Semi-lipschitz functions, best approximation, and fuzzy quasi-metric hyperspaces [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/5769
395

Using Kullback-Leibler Divergence to Analyze the Performance of Collaborative Positioning

Nounagnon, Jeannette Donan 12 July 2016 (has links)
Geolocation accuracy is a very crucial and a life-or-death factor for rescue teams. Natural disasters or man-made disasters are just a few convincing reasons why fast and accurate position location is necessary. One way to unleash the potential of positioning systems is through the use of collaborative positioning. It consists of simultaneously solving for the position of two nodes that need to locate themselves. Although the literature has addressed the benefits of collaborative positioning in terms of accuracy, a theoretical foundation on the performance of collaborative positioning has been disproportionally lacking. This dissertation uses information theory to perform a theoretical analysis of the value of collaborative positioning.The main research problem addressed states: 'Is collaboration always beneficial? If not, can we determine theoretically when it is and when it is not?' We show that the immediate advantage of collaborative estimation is in the acquisition of another set of information between the collaborating nodes. This acquisition of new information reduces the uncertainty on the localization of both nodes. Under certain conditions, this reduction in uncertainty occurs for both nodes by the same amount. Hence collaboration is beneficial in terms of uncertainty. However, reduced uncertainty does not necessarily imply improved accuracy. So, we define a novel theoretical model to analyze the improvement in accuracy due to collaboration. Using this model, we introduce a variational analysis of collaborative positioning to deter- mine factors that affect the improvement in accuracy due to collaboration. We derive range conditions when collaborative positioning starts to degrade the performance of standalone positioning. We derive and test criteria to determine on-the-fly (ahead of time) whether it is worth collaborating or not in order to improve accuracy. The potential applications of this research include, but are not limited to: intelligent positioning systems, collaborating manned and unmanned vehicles, and improvement of GPS applications. / Ph. D.
396

Temporal rate is not a distinct perceptual metric.

Motala, A., Heron, James, McGraw, P.V., Roach, N.W., Whitaker, D. 03 June 2020 (has links)
Yes / Sensory adaptation experiments have revealed the existence of ‘rate after-effects’ - adapting to a relatively fast rate makes an intermediate test rate feel slow, and adapting to a slow rate makes the same moderate test rate feel fast. The present work aims to deconstruct the concept of rate and clarify how exactly the brain processes a regular sequence of sensory signals. We ask whether rate forms a distinct perceptual metric, or whether it is simply the perceptual aggregate of the intervals between its component signals. Subjects were exposed to auditory or visual temporal rates (a ‘slow’ rate of 1.5 Hz and a ‘fast’ rate of 6 Hz), before being tested with single unfilled intervals of varying durations. Results show adapting to a given rate strongly influences the perceived duration of a single empty interval. This effect is robust across both interval reproduction and duration discrimination judgments. These findings challenge our understanding of rate perception. Specifically, they suggest that contrary to some previous assertions, the perception of sequence rate is strongly influenced by the perception of the sequence’s component duration intervals. / This work was supported by a Wellcome Trust [WT097387] grant to NWR
397

A Comparative Study of Real time Video Streaming Solutions / En jämförande studie av realtidslösningar för streaming av video

Eklund, Carl January 2024 (has links)
With the emergence of video-streaming applications extending beyond the entertainment section and becoming more accessible in everyday interactions. However, developing a video live-streaming application and choosing which services to use can be a hard task whether to go for a pre-built solution or build your own foundation. When deciding which services to include in your product a lot of aspects have to be taken into consideration, regarding performance and so on. The aim of this thesis is to emphasize the importance and relevancy of the development efficiency metric, including soft metrics such as maintainability and understandability. During this thesis three different video live-streaming services were chosen to be compared against each other regarding development efficiency: WebRTC, Agora and GetStream. Baseline applications were developed where each respective chosen service was implemented and further evaluated based on development efficiency. According to development efficiency, GetStream had the highest score compared to the other services and therefore should be the easiest to maintain and understand. On the other hand, WebRTC had the lowest development efficiency score and therefore should be the hardest to maintain and understand, however by choosing WebRTC you are not opting into a third-party service and therefore have more control over the implementation. Overall, it can be concluded that deciding which services to include a multitude of aspects has to be considered.
398

The differential geometry of the fibres of an almost contract metric submersion

Tshikunguila, Tshikuna-Matamba 10 1900 (has links)
Almost contact metric submersions constitute a class of Riemannian submersions whose total space is an almost contact metric manifold. Regarding the base space, two types are studied. Submersions of type I are those whose base space is an almost contact metric manifold while, when the base space is an almost Hermitian manifold, then the submersion is said to be of type II. After recalling the known notions and fundamental properties to be used in the sequel, relationships between the structure of the fibres with that of the total space are established. When the fibres are almost Hermitian manifolds, which occur in the case of a type I submersions, we determine the classes of submersions whose fibres are Kählerian, almost Kählerian, nearly Kählerian, quasi Kählerian, locally conformal (almost) Kählerian, Gi-manifolds and so on. This can be viewed as a classification of submersions of type I based upon the structure of the fibres. Concerning the fibres of a type II submersions, which are almost contact metric manifolds, we discuss how they inherit the structure of the total space. Considering the curvature property on the total space, we determine its corresponding on the fibres in the case of a type I submersions. For instance, the cosymplectic curvature property on the total space corresponds to the Kähler identity on the fibres. Similar results are obtained for Sasakian and Kenmotsu curvature properties. After producing the classes of submersions with minimal, superminimal or umbilical fibres, their impacts on the total or the base space are established. The minimality of the fibres facilitates the transference of the structure from the total to the base space. Similarly, the superminimality of the fibres facilitates the transference of the structure from the base to the total space. Also, it is shown to be a way to study the integrability of the horizontal distribution. Totally contact umbilicity of the fibres leads to the asymptotic directions on the total space. Submersions of contact CR-submanifolds of quasi-K-cosymplectic and quasi-Kenmotsu manifolds are studied. Certain distributions of the under consideration submersions induce the CR-product on the total space. / Mathematical Sciences / D. Phil. (Mathematics)
399

Neue Indexingverfahren für die Ähnlichkeitssuche in metrischen Räumen über großen Datenmengen / New indexing techniques for similarity search in metric spaces

Guhlemann, Steffen 06 July 2016 (has links) (PDF)
Ein zunehmend wichtiges Thema in der Informatik ist der Umgang mit Ähnlichkeit in einer großen Anzahl unterschiedlicher Domänen. Derzeit existiert keine universell verwendbare Infrastruktur für die Ähnlichkeitssuche in allgemeinen metrischen Räumen. Ziel der Arbeit ist es, die Grundlage für eine derartige Infrastruktur zu legen, die in klassische Datenbankmanagementsysteme integriert werden könnte. Im Rahmen einer Analyse des State of the Art wird der M-Baum als am besten geeignete Basisstruktur identifiziert. Dieser wird anschließend zum EM-Baum erweitert, wobei strukturelle Kompatibilität mit dem M-Baum erhalten wird. Die Abfragealgorithmen werden im Hinblick auf eine Minimierung notwendiger Distanzberechnungen optimiert. Aufbauend auf einer mathematischen Analyse der Beziehung zwischen Baumstruktur und Abfrageaufwand werden Freiheitsgrade in Baumänderungsalgorithmen genutzt, um Bäume so zu konstruieren, dass Ähnlichkeitsanfragen mit einer minimalen Anzahl an Anfrageoperationen beantwortet werden können. / A topic of growing importance in computer science is the handling of similarity in multiple heterogenous domains. Currently there is no common infrastructure to support this for the general metric space. The goal of this work is lay the foundation for such an infrastructure, which could be integrated into classical data base management systems. After some analysis of the state of the art the M-Tree is identified as most suitable base and enhanced in multiple ways to the EM-Tree retaining structural compatibility. The query algorithms are optimized to reduce the number of necessary distance calculations. On the basis of a mathematical analysis of the relation between the tree structure and the query performance degrees of freedom in the tree edit algorithms are used to build trees optimized for answering similarity queries using a minimal number of distance calculations.
400

Examining fish quality : the evaluation of the use of lipids as a measure of condition in wild Atlantic salmon

Howe, Alexandra Jane January 2015 (has links)
Considering the response of organisms to their environment is difficult; it is made more so if population numbers cannot be closely monitored. In such cases different methods of population assessment are required. This thesis uses lipids as a measure of Atlantic salmon (Salmo salar L.) quality and investigates its usefulness in indicating fish condition. The first study examines the relationship between fish total lipid content and W[sub]R condition factor; this study clearly demonstrates that there is a significant positive relationship between the condition factor of a fish and its total lipid content. In the following study the lipid storage between the different tissues of the Atlantic salmon is considered. This indicates that the red muscle and the adipose tissues hold higher concentrations of lipid than the white muscle. However, the white muscle makes up the majority of lipid tissue mass in the Atlantic salmon so contains the bulk of stored lipid in a fish, at low concentration. The next study investigates the effect of spawning on Atlantic salmon condition. Salmon can be seen preferentially conserving lipid in their musculature and drawing down the lipid stored in their adipose tissues. The following study looked at one key lipid group, triacylglycerides, in salmon. Triacylglycerides are energetically important in fish and this study found that the spawning process depleted triacylglyceride reserves, but that the red muscle conserves triacylglycerides even after spawning. The final study considers the relationship between maternal quality and egg quality, identifying that longer Atlantic salmon produce eggs with more lipid after spawning migration. Egg lipid concentrations were comparably maintained between fish. Monitoring quality in this way is a useful tool to determine population wellbeing and help indicate where populations are compromised.

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