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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.
31

Real-time Transmission Over Internet

Gao, Qi January 2004 (has links)
With the Internet expansion, real-time transmission over Internet is becoming a new promising application. Successful real-time communication over IP networks requires reasonably reliable, low delay, low loss date transport. Since Internet is a non-synchronous packet switching network, high load and lack of guarantees on data delivery make real-time communication such as Voice and Video over IP a challenging application to become realistic on the Internet. This thesis work is composed of two parts within real-time voice and video communication: network simulation and measurement on the real Internet. In the network simulation, I investigate the requirement for the network"overprovisioning"in order to reach certain quality-of-service. In the experiments on the real Internet, I simulate real-time transmission with UDP packets along two different traffic routes and analyze the quality-of- service I get in each case. The overall contribution of this work is: To create scenarios to understand the concept of overprovisioning and how it affects the quality-of-service. To develop a mechanism to measure the quality-of-service for real-time traffic provided by the current best-effort network.
32

Adaptive Adjustment on CP/CF Ratio for Improving QoS Support in IEEE 802.11e Networks

Jiang, Chih-Shiuan 11 August 2005 (has links)
As the development of wireless networks, no doubt it brings much more convenience to us. Besides, QoS (Quality of Service) demand emerges due to the popularity of multimedia traffic. Therefore, it is quite worthwhile to do researches about how to provide QoS in wireless networks. 802.11 wireless networks are the most widespread wireless networks currently, and the main goal of 802.11e task group is to support QoS. This thesis proposes a method for further improving QoS under 802.11e environment. According to varying ratio of CBR-like / VBR-like traffic, it adaptively adjusts the proportion of CP/CF medium access mode, and selects the corresponding admission control mechanism. The basic philosophy is to choose favorable transfer ways for different traffic characteristics, hence to reduce average delay. In addition to reduce average delay, we propose another mechanism to maintain or improve system throughput as well.
33

Automatic Source Code Classification : Classifying Source Code for a Case-Based Reasoning System

Nordström, Markus January 2015 (has links)
This work has investigated the possibility of classifying Java source code into cases for a case-based reasoning system. A Case-Based Reasoning system is a problem solving method in Artificial Intelligence that uses knowledge of previously solved problems to solve new problems. A case in case-based reasoning consists of two parts: the problem part and solution part. The problem part describes a problem that needs to be solved and the solution part describes how this problem was solved. In this work, the problem is described as a Java source file using words that describes the content in the source file and the solution is a classification of the source file along with the source code. To classify Java source code, a classification system was developed. It consists of four analyzers: type filter, documentation analyzer, syntactic analyzer and semantic analyzer. The type filter determines if a Java source file contains a class or interface. The documentation analyzer determines the level of documentation in asource file to see the usefulness of a file. The syntactic analyzer extracts statistics from the source code to be used for similarity, and the semantic analyzer extracts semantics from the source code. The finished classification system is formed as a kd-tree, where the leaf nodes contains the classified source files i.e. the cases. Furthermore, a vocabulary was developed to contain the domain knowledge about the Java language. The resulting kd-tree was found to be imbalanced when tested, as the majority of source files analyzed were placed inthe left-most leaf nodes. The conclusion from this was that using documentation as a part of the classification made the tree imbalanced and thus another way has to be found. This is due to the fact that source code is not documented to such an extent that it would be useful for this purpose.
34

USING CASE-BASED REASONING FOR PREDICTING ENERGY USAGE

Bjurén, Johan January 2013 (has links)
In this study, the inability to in a future meet the electricity demand and the urge to change the consumption behavior considered. In a smart grid context there are several possible ways to do this. Means include ways to increase the consumer’s awareness, add energy storages or build smarter homes which can control the appliances. To be able to implement these, indications on how the future consumption will be could be useful. Therefore we look further into how a framework for short-term consumption predictions can be created using electricity consumption data in relation to external factors. To do this a literature study is made to see what kind of methods that are relevant and which qualities is interesting to look at in order to choose a good prediction method. Case Based Reasoning seemed to be able to be suitable method. This method was examined further and built using relational databases. After this the method was tested and evaluated using datasets and evaluation methods CV, MBE and MAPE, which have previously been used in the domain of consumption prediction. The result was compared to the results of the winning methods in the ASHRAE competition. The CBR method was expected to perform better than what it did, and still not as good as the winning methods from the ASHRAE competition. The result showed that the CBR method can be used as a predictor and has potential to make good energy consumption predictions. and there is room for improvement in future studies.
35

Inovace klasifikace a zkoušení podložních zemin pro realizaci lesních odvozních cest

Tvrdý, Daniel January 2014 (has links)
Basic presumption of good functionality of forest roads is not only high quality of laminars in flexible pavement, but also right distribution of elasticity modules in soil plain and it's protection against degradation during the process of building. Materials used for TA ČR project, which were isolated from forest roads subsoil, were analyzed in soil mechanics laboratory of Geostar s.r.o. company for the purposes of diploma thesis. Basic laboratory tests were carried out in order to classify soils. Sub-component is to propose a simplified classification of soils for the implementation of forest haul routes. In this work are validated according to the static load tests ( SZZ ) and dynamic light boards ( LDD ) . The thesis includes evaluation of the quality of existing forest roads for faults and failure on forest roads classes 1L and 2L with different surfaces and ground covers .
36

Case Representation Methodology for a Scalable Case-Based Reasoning

Larsson, Carl January 2018 (has links)
Case-Based Reasoning (CBR) is an Artificial Intelligence (AI) methodology and a growing field of research. CBR uses past experiences to help solve new problems the system faces. To do so CBR is comprised of a few core parts, such as case representation, case library, case retrieval, and case adaptation. This thesis will focus on the case representation aspect of CBR systems and presents a scalable case representation for big data environments. One aspect of focus on big data environments is also the focus of a MapReduce environment. MapReduce is a software framework enabling the use of a Map and Reduce function to be executed over a network cluster. This thesis conducts a systematic literature review to gain an understanding of the current case representations used in various CBR systems. The systematic literature review presents two major types of case representations, hierarchical and vector-based representations. However, the review also finds that the field of case representation research to be lacking. Most papers were focused on other aspects of CBR systems, mainly case retrieval. This thesis also proposes the design of a scalable and distributed case representation. The proposed case representation is of a hierarchical nature and is designed in such a way that it can utilize a MapReduce environment for working with the case library in components such as case retrieval. In the proof of concept, part of the case representation was implemented and tested using two data-sets. One data-set contains EEG sensor data measuring sleepiness while the other contains information about employees health and time taken off work. These tests show the case representation adequately representing the respective data-sets. The strength of the proposed case representation method is further discussed using a cross of papers. These papers cover the use of XML structured data in both CBR and MapReduce showing how this case representation is suitable for both uses. This shows strong capabilities of the case representation being further implemented and the addition of a case retrieval method to utilize it.
37

A new 3D shape descriptor based on depth complexity and thickness information / Um novo descritor de formas 3D baseado em informações de depth complexity e thickness

Schmitt, Wagner January 2015 (has links)
Modelos geométricos desempenham um papel fundamental em divérsas áreas, desde a indústria do entretenimento até aplicações científicas. Para reduzir o elevado custo de criação de um modelo 3D, a reutilização de modelos existentes é a solução ideal. Recuperação de modelos 3D utilizam técnicas baseadas em conteúdo (do inglês CBR) que auxiliam a busca de modelos desejados em repositórios massivos, muitos disponíveis publicamente na Internet. Pontos principais para técnicas CBR eficientes e eficazes são descritores de forma que capturam com precisão as características de uma forma 3D e são capazes de discriminar entre diferentes formas. Nós apresentamos um descritor com base na distribuição de duas características globais, extraídas de uma forma 3D, depth complexity e thickness, que, respectivamente, capturam aspectos da topologia e da geometria das formas 3D. O descritor final, chamado DCT (depth complexity and thickness histogram), é um histograma 2D invariante a translações, rotações e escalas das formas geométricas. Nós eficientemente implementamos o DCT na GPU, permitindo sua utilização em consultas em tempo real em grandes bases de dados de modelos 3D. Nós validamos o DCT com as Princeton e Toyohashi Forma Benchmarks, contendo 1815 e 10000 modelos respectivamente. Os resultados mostram que DCT pode discriminar classes significativas desses benchmarks, é rápido e robusto contra transformações de forma e diferentes níveis de subdivisão e suavidade dos modelos. / Geometric models play a vital role in several fields, from the entertainment industry to scientific applications. To reduce the high cost of model creation, reusing existing models is the solution of choice. Model reuse is supported by content-based shape retrieval (CBR) techniques that help finding the desired models in massive repositories, many publicly available on the Internet. Key to efficient and effective CBR techniques are shape descriptors that accurately capture the characteristics of a shape and are able to discriminate between different shapes. We present a descriptor based on the distribution of two global features measured on a 3D shape, depth complexity and thickness, which respectively capture aspects of the geometry and topology of 3D shapes. The final descriptor, called DCT (depth complexity and thickness histogram), is a 2D histogram that is invariant to the translation, rotation and scale of geometric shapes. We efficiently implement the DCT on the GPU, allowing its use in real-time queries of large model databases. We validate the DCT with the Princeton and Toyohashi Shape Benchmarks, containing 1815 and 10000 models respectively. Results show that DCT can discriminate meaningful classes of these benchmarks, and is fast to compute and robust against shape transformations and different levels of subdivision and smoothness.
38

Studium vlivu inhibitorů cyklin-dependentních kinas na expresi vybraných AKR a CBR enzymů v lidských buněčných liniích. / Study of the effect of cyclin-dependent kinase inhibitors on the expression of selected AKR and CBR enzymes in human cell lines.

Kouklíková, Etela January 2018 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Bc. Etela Kouklíková Supervisor: RNDr. Eva Novotná, Ph.D. Title of diploma thesis: Study of the effect of cyclin-dependent kinase inhibitors on the expression of selected AKR and CBR enzymes in human cell lines Cyclin-dependent kinase inhibitors (CDKi) are considered as a suitable treatment especially in patients with wrong prognosis or advanced stage of cancer. It has only recently been discovered that CDKi are able to influence the activity of some enzymes from aldo-keto reductase (AKR) and short-chain dehydrogenase/reductase (SDR) superfamilies. AKR and SDR enzymes belong to a group of carbonyl reducing enzymes that are involved in the metabolism of endobiotics and xenobiotics. An important group of drugs that are metabolized by these enzymes to less efficient compounds are anthracyclines. The aim of this diploma thesis was to find out whether purvalanol A, roscovitin, dinaciclib, AZD5438 and R547 can affect the expression of the most important anthracycline reductases (AKR1A1, AKR1B10, AKR1C3, AKR7A2 and CBR1) in human HepG2 and HL-60 cell lines. Expression of anthracycline reductases in cells exposed to CDKi was evaluated at mRNA level by RT-qPCR and at protein level by Western blotting. The...
39

A new 3D shape descriptor based on depth complexity and thickness information / Um novo descritor de formas 3D baseado em informações de depth complexity e thickness

Schmitt, Wagner January 2015 (has links)
Modelos geométricos desempenham um papel fundamental em divérsas áreas, desde a indústria do entretenimento até aplicações científicas. Para reduzir o elevado custo de criação de um modelo 3D, a reutilização de modelos existentes é a solução ideal. Recuperação de modelos 3D utilizam técnicas baseadas em conteúdo (do inglês CBR) que auxiliam a busca de modelos desejados em repositórios massivos, muitos disponíveis publicamente na Internet. Pontos principais para técnicas CBR eficientes e eficazes são descritores de forma que capturam com precisão as características de uma forma 3D e são capazes de discriminar entre diferentes formas. Nós apresentamos um descritor com base na distribuição de duas características globais, extraídas de uma forma 3D, depth complexity e thickness, que, respectivamente, capturam aspectos da topologia e da geometria das formas 3D. O descritor final, chamado DCT (depth complexity and thickness histogram), é um histograma 2D invariante a translações, rotações e escalas das formas geométricas. Nós eficientemente implementamos o DCT na GPU, permitindo sua utilização em consultas em tempo real em grandes bases de dados de modelos 3D. Nós validamos o DCT com as Princeton e Toyohashi Forma Benchmarks, contendo 1815 e 10000 modelos respectivamente. Os resultados mostram que DCT pode discriminar classes significativas desses benchmarks, é rápido e robusto contra transformações de forma e diferentes níveis de subdivisão e suavidade dos modelos. / Geometric models play a vital role in several fields, from the entertainment industry to scientific applications. To reduce the high cost of model creation, reusing existing models is the solution of choice. Model reuse is supported by content-based shape retrieval (CBR) techniques that help finding the desired models in massive repositories, many publicly available on the Internet. Key to efficient and effective CBR techniques are shape descriptors that accurately capture the characteristics of a shape and are able to discriminate between different shapes. We present a descriptor based on the distribution of two global features measured on a 3D shape, depth complexity and thickness, which respectively capture aspects of the geometry and topology of 3D shapes. The final descriptor, called DCT (depth complexity and thickness histogram), is a 2D histogram that is invariant to the translation, rotation and scale of geometric shapes. We efficiently implement the DCT on the GPU, allowing its use in real-time queries of large model databases. We validate the DCT with the Princeton and Toyohashi Shape Benchmarks, containing 1815 and 10000 models respectively. Results show that DCT can discriminate meaningful classes of these benchmarks, and is fast to compute and robust against shape transformations and different levels of subdivision and smoothness.
40

A new 3D shape descriptor based on depth complexity and thickness information / Um novo descritor de formas 3D baseado em informações de depth complexity e thickness

Schmitt, Wagner January 2015 (has links)
Modelos geométricos desempenham um papel fundamental em divérsas áreas, desde a indústria do entretenimento até aplicações científicas. Para reduzir o elevado custo de criação de um modelo 3D, a reutilização de modelos existentes é a solução ideal. Recuperação de modelos 3D utilizam técnicas baseadas em conteúdo (do inglês CBR) que auxiliam a busca de modelos desejados em repositórios massivos, muitos disponíveis publicamente na Internet. Pontos principais para técnicas CBR eficientes e eficazes são descritores de forma que capturam com precisão as características de uma forma 3D e são capazes de discriminar entre diferentes formas. Nós apresentamos um descritor com base na distribuição de duas características globais, extraídas de uma forma 3D, depth complexity e thickness, que, respectivamente, capturam aspectos da topologia e da geometria das formas 3D. O descritor final, chamado DCT (depth complexity and thickness histogram), é um histograma 2D invariante a translações, rotações e escalas das formas geométricas. Nós eficientemente implementamos o DCT na GPU, permitindo sua utilização em consultas em tempo real em grandes bases de dados de modelos 3D. Nós validamos o DCT com as Princeton e Toyohashi Forma Benchmarks, contendo 1815 e 10000 modelos respectivamente. Os resultados mostram que DCT pode discriminar classes significativas desses benchmarks, é rápido e robusto contra transformações de forma e diferentes níveis de subdivisão e suavidade dos modelos. / Geometric models play a vital role in several fields, from the entertainment industry to scientific applications. To reduce the high cost of model creation, reusing existing models is the solution of choice. Model reuse is supported by content-based shape retrieval (CBR) techniques that help finding the desired models in massive repositories, many publicly available on the Internet. Key to efficient and effective CBR techniques are shape descriptors that accurately capture the characteristics of a shape and are able to discriminate between different shapes. We present a descriptor based on the distribution of two global features measured on a 3D shape, depth complexity and thickness, which respectively capture aspects of the geometry and topology of 3D shapes. The final descriptor, called DCT (depth complexity and thickness histogram), is a 2D histogram that is invariant to the translation, rotation and scale of geometric shapes. We efficiently implement the DCT on the GPU, allowing its use in real-time queries of large model databases. We validate the DCT with the Princeton and Toyohashi Shape Benchmarks, containing 1815 and 10000 models respectively. Results show that DCT can discriminate meaningful classes of these benchmarks, and is fast to compute and robust against shape transformations and different levels of subdivision and smoothness.

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