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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.
81

Dimensionality Reduction for Commercial Vehicle Fleet Monitoring

Baldiwala, Aliakbar 25 October 2018 (has links)
A variety of new features have been added in the present-day vehicles like a pre-crash warning, the vehicle to vehicle communication, semi-autonomous driving systems, telematics, drive by wire. They demand very high bandwidth from in-vehicle networks. Various electronic control units present inside the automotive transmit useful information via automotive multiplexing. Automotive multiplexing allows sharing information among various intelligent modules inside an automotive electronic system. Optimum functionality is achieved by transmitting this data in real time. The high bandwidth and high-speed requirement can be achieved either by using multiple buses or by implementing higher bandwidth. But, by doing so the cost of the network and the complexity of the wiring in the vehicle increases. Another option is to implement higher layer protocol which can reduce the amount of data transferred by using data reduction (DR) techniques, thus reducing the bandwidth usage. The implementation cost is minimal as only the changes are required in the software and not in hardware. In our work, we present a new data reduction algorithm termed as “Comprehensive Data Reduction (CDR)” algorithm. The proposed algorithm is used for minimization of the bus utilization of CAN bus for a future vehicle. The reduction in the busload was efficiently made by compressing the parameters; thus, more number of messages and lower priority messages can be efficiently sent on the CAN bus. The proposed work also presents a performance analysis of proposed algorithm with the boundary of fifteen compression algorithm, and Compression area selection algorithms (Existing Data Reduction Algorithm). The results of the analysis show that proposed CDR algorithm provides better data reduction compared to earlier proposed algorithms. The promising results were obtained in terms of reduction in bus utilization, compression efficiency, and percent peak load of CAN bus. This Reduction in the bus utilization permits to utilize a larger number of network nodes (ECU’s) in the existing system without increasing the overall cost of the system. The proposed algorithm has been developed for automotive environment, but it can also be utilized in any applications where extensive information transmission among various control units is carried out via a multiplexing bus.
82

Estudo do efeito de dipolos em arranjos de antenas adaptativas de sistemas de comunica??o DS-CDMA

Torquato, Ciro Augusto Paula 17 October 2003 (has links)
Made available in DSpace on 2014-12-17T14:55:20Z (GMT). No. of bitstreams: 1 CiroAPT.pdf: 942128 bytes, checksum: 56e26f87c283ff837ca5212f483b63ad (MD5) Previous issue date: 2003-10-17 / This master dissertation introduces a study about some aspects that determine the aplication of adaptative arrays in DS-CDMA cellular systems. Some basics concepts and your evolution in the time about celular systems was detailed here, meanly the CDMA tecnique, specialy about spread-codes and funtionaly principies. Since this, the mobile radio enviroment, with your own caracteristcs, and the basics concepts about adaptive arrays, as powerfull spacial filter was aborded. Some adaptative algorithms was introduced too, these are integrants of the signals processing, and are answerable for weights update that influency directly in the radiation pattern of array. This study is based in a numerical analysis of adaptative array system behaviors related to the used antenna and array geometry types. All the simulations was done by Mathematica 4.0 software. The results for weights convergency, square mean error, gain, array pattern and supression capacity based the analisis made here, using RLS (supervisioned) and LSDRMTA (blind) algorithms / Esta disserta??o de mestrado vem trazer um estudo sobre alguns aspectos que influenciam na aplica??o de antenas adaptativas em sistemas celulares DS-CDMA (ou simplesmente CDMA). Foram detalhados alguns conceitos b?sicos a respeito do sistema celular e em geral, bem como sua evolu??o ao longo do tempo, dando ?nfase ? t?cnica CDMA, no que diz respeito aos c?digos de espalhamento e princ?pio de funcionamento. A partir disso, o ambiente de r?dio m?vel, com suas caracter?sticas peculiares, foi abordado, bem como os conceitos b?sicos em que se baseiam o sistema de antenas adaptativas com sua poderosa capacidade de filtragem espacial, capaz de reduzir significativamente o efeito de sinais indesejados. Tamb?m alguns algoritmos adaptativos foram discutidos, esses s?o integrantes do processamento dos sinais captados pelos arranjos, e s?o respons?veis pela atualiza??o dos pesos que de certa forma controlar?o o diagrama de radia??o do arranjo. Mais especificamente, esse trabalho fundamentou-se na an?lise, mediante simula??es computacionais, do comportamento do sistema de antenas adaptativas face ao tipo de antena e ao tipo (geometria) de arranjo empregados. Todas as simula??es foram feitas utilizando o software Mathematica 4.0. Os resultados para a converg?ncia dos pesos, erro m?dio quadr?tico, ganho, diagrama de radia??o e capacidade de supress?o foram as grandezas que basearam as an?lises aqui feitas, utilizando para isso, os algoritmos RLS (supervisionado) e LSDRMTA (cego)
83

Sobre a incomunicabilidade humana / Sobre a incomunicabilidade humana

Claudenir Modolo Alves 05 June 2009 (has links)
Esta dissertação versa sobre a incomunicabilidade humana. A pergunta problematizadora que temos como objetivo aprofundar é: o ser humano é, ontologicamente, um ser capaz de se comunicar? ou de outra forma: é possível a existência da comunicação? A hermenêutica imanente dos textos de natureza filosófica, seguida da reflexão analítica, nos aproxima da problemática sobre a incomunicabilidade humana, iluminando os enfoques chave do estado instaurado de incomunicação radical e generalizada, por outro lado a possibilidade do ser de relacionar-se e abrir a comunicação para sua existência. A possibilidade do ser humano de relacionar-se é mínima no sistema planetário de comunicação, o que nos faz concluir que vivemos na era da incomunicabilidade humana, por primeiro da incomunicabilidade entre eu e o outro. / This dissertation deals with human incommunicability. We intend to further study the following problematizing issue: Ontologically speaking, is the human being capable of communicating? In other words: can communication exist? The immanent hermeneutics of philosophical texts, followed by analytical reflection, leads us to the problem of human incommunicability, throws light on key approaches to the state of radical and generalized incommunication, and, on the other hand, the possibility for human beings to establish relationships and open lines of communication for their survival. The planets communication system allows for minimal possibilities of human beings establishing relationships; we have, therefore, to conclude that we live in an era of human incommunicability, starting with the incommunicability between the self and others.
84

Sistema de comunicação utilizando sinais caóticos de tempo discreto em canais de banda limitada

Fanganiello, Renato Dalto 03 August 2010 (has links)
Made available in DSpace on 2016-03-15T19:37:30Z (GMT). No. of bitstreams: 1 Renato Dalto Fanganiello.pdf: 1457160 bytes, checksum: bf6c236fbb03a0209447afecf0831326 (MD5) Previous issue date: 2010-08-03 / Universidade Presbiteriana Mackenzie / Many synchronization methods for chaotic systems have been proposed over the past decades seeking for applications in communications. However, they have not satisfactorily performed when submitted to non-ideal communication channels. In this work, a discrete-time master-slave system based on Wu and Chua's synchronization model is considered. It is shown that it is possible to achieve synchronization under bandwidth limitations imposed by the communication channel by applying a digital filter in the feedback loop reponsible for the generation of the chaotic signal that will be transmitted. Furthermore, an analytical demonstration is presented showing that synchronization is not affected by the presence of digital filter introduced in the communication system. Results of computacional simulations relating the filter's parameters, such as its order and cut-off frequency, to maximum Lyapunov expoent of the transmitter system, which determines if the transmitted signal is chaotic or periodic, are also shown. / No decorrer das últimas décadas, muitos métodos de sincronismo para sistemas caóticos têm sido propostos visando aplicações em comunicações. No entanto, suas performances não têm se mostrado satisfatórias quando submetidos a condições não ideais de canais de transmissão. Neste trabalho considera-se um sistema mestre-escravo de tempo discreto baseado no modelo de sincronismo de Wu e Chua. Mostra-se que é possível atingir o sincronismo, mesmo quando há limitação de largura de banda imposta pelo canal de comunicação, por meio da introdução de um filtro digital que limita o espectro de potência na malha de realimentação responsável pela geração do sinal que será transmitido. Ademais, demonstra-se analiticamente que a presença do filtro digital introduzido no sistema de comunicação não interfere no seu sincronismo. Também são mostrados resultados de simulações computacionais que relacionam os parâmetros do filtro digital introduzido no sistema de comunicação, como ordem e frequência de corte, com o maior expoente de Lyapunov do sistema transmissor, que determina se o sinal transmitido será caótico ou periódico.
85

Proposta de alocação de baterias em redes de sensores sem fio orientada à maximização do tempo de vida / Proposal of battery allocation on wireless sensor networks oriented to lifetime maximization

Miranda, Felipe Antonio Moura 18 August 2018 (has links)
Orientador: Carlos Alberto dos Reis Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T23:24:59Z (GMT). No. of bitstreams: 1 Miranda_FelipeAntonioMoura_M.pdf: 6566309 bytes, checksum: b49e924fd653f7969996d5f0c2fd2a0a (MD5) Previous issue date: 2011 / Resumo: Os avanços recentes na tecnologia das Redes de Sensores Sem Fio mostraram que enquanto suas limitações computacionais são questões passageiras, limitações de energia são problemas mais complicados. Neste trabalho, foi proposta uma estratégia que visa o aumento do tempo de vida de Redes de Sensores Sem Fio. A principal motivação deste trabalho é que a limitação de energia é um sério problema inerente às Redes de Sensores Sem Fio, causado pelo fato de que os motes utilizados geralmente são equipados de pequenas baterias, conseqüentemente, dotadas de pequenas cargas de energia. Além disso, a troca de baterias após a alocação de todos os motes é uma tarefa de grande dificuldade, resultando em tempos de vida curtos e em desperdício de energia. A estratégia proposta neste trabalho é baseada na alocação de energia guiada pela estimativa de consumo de cada mote, independentemente da topologia física da rede. A validação desta estratégia foi feita através de simulações utilizando motes montados com modelos de diversos componentes utilizados em redes reais. Para avaliar a eficácia da estratégia, a mesma foi testada em redes de diferentes topologias, alcançando o aumento no tempo de vida das redes e na redução do desperdício de energia em todos os cenários / Abstract: The recent advances in Wireless Sensor Networks technologies showed that while computational limitations are transient issues, energy limitations are much more complicated problems. In this work, a strategy aiming the lifetime increment of Wireless Sensor Networks is proposed. The main motivation of this work is that energy limitation is a serious inherent problem to Wireless Sensor Networks, caused by the fact that their motes generally use small batteries, consequently, with a small amount of energy. Besides that, changing batteries after all motes deployment is such a hard task, resulting in short lifetimes and energy waste. The strategy proposed in this work is based on the energy allocation guided by the estimation of each node's consumption, no matter what is the network topology. The validation of this strategy was made by mean of simulations using motes made with models of many commercial devices used in real networks. To evaluate the strategy effectiveness, it was tested on different networks topologies, achieving network lifetime increment and energy waste reduction on all scenarios / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica
86

An investigation of social computing

Schlenkrich, Lara January 2009 (has links)
Social network sites have recently become extremely popular online destinations as they offer users easy ways to build and maintain their relationships with each other. Consequently, students, lecturers, teachers, parents and businesses are using these tools to communicate with each other in a fast and cost-effective manner. However, literature suggests that the full potential of social network sites has not yet been revealed since users are still battling to overcome the various negative characteristics surrounding these sites. A framework for appropriate use of these sites is needed so that users are able to overcome these negative aspects, allowing them to be more effective and use the sites successfully. The goal of this research is to construct a framework for perceived successful use of social computing tools in educational institutions. This framework will include critical success factors that need to be adopted by users in order to develop the positive aspects of social computing, while at the same time overcoming the disadvantages experienced by users. Factors for successful use were derived from the literature and consolidated into a theoretical framework in order to understand the factors that drive successful use of social network sites. Measures used to test successful use of social network sites were also derived from these sources and were included in the same theoretical framework; these measures allow users to evaluate the extent of perceived successful use of social network sites. This framework was tested empirically by means of a pilot study and online survey, and revised according to the results of the survey. The factors were identified using Cronbach alpha coefficients (in the pilot study) and exploratory factor analysis to confirm the reliability of the scales developed. Pearson product-moment correlation coefficient analysis, t-tests and Pearson Chi-Square tests were used to measure the relationships amongst the variables in the framework proposed in this research. The factors influencing perceived successful use of social network sites were identified by the empirical study as: • Privacy and Security Settings need to be enabled. These are split into: - Settings: content that users allow others to see - Viewers: people who are allowed onto a user's profile • It is necessary for users to practise Legal and Acceptable Activities when using social network sites • Suspect Information needs to be checked before sharing it with others • Personal and Professional Time needs to be separated to ensure that work is completed before social activities occur • Users need to practise Professional and Ethical Behaviour • Users need to have a Positive Attitude when using social network sites • Usability of sites affects their success. This includes: - technical capacity (broadband) - ease of use - functionality (range of features and functions) • Current and Controversial Issues need to be discussed on social network sites. The extent to which social network sites are being used successfully can be evaluated by the presence of the following measures: • Range of Content must be available to users. This includes: - Content displayed on profiles - Viewers able to visit profiles • Visitors Behaviour is monitored and no unwanted visitors are present users' profiles • Social Contracts found on sites are followed by users • Critical Thinking Skills and Accurate Information are displayed by users • Work is completed before social activities occur on sites • A Variety of Users is present on sites • Collaboration between people as well as variety of opinions exist on sites • Social Capital (well-being) is present after users have been on sites • Learning and Advising Skills are enhanced on sites. The framework developed provides users with a useful instrument to overcome the negative characteristics associated with social network sites. If used successfully, social network sites can offer lecturers and students a unique method to develop their relationship, creating a positive learning experience.
87

Návrh na zvýšení efektivity interpersonální komunikace ve firmě / Proposal to Improve the Effectiveness of Interpersonal Communication in Company

Petrášová, Lenka January 2010 (has links)
The key objective of this master's thesis is to elucidate processes that increase the effectiveness of interpersonal communication in company Saint-Gobain Weber Terranova, Inc. The paper is divided into two main sections. The first part provides a theoretical summary. Followed second empirical section which is based on research of actual quality of interpersonal communication in company. The results of a questionary research as the main data-collecting tool will make a headstone for a set of proposals which will result in more effective internal communication in the above-mentioned company.
88

Mobile Speditionslogistikunterstützung durch integrierte Kommunikationssysteme

Gruhn, Volker, Hülder, Malte, Ijioui, Raschid, Schöpe, Lothar 28 January 2019 (has links)
Für Speditionsunternehmen liegt ein erhebliches Potential zur Effizienzsteigerung in der verbesserten Kommunikation zwischen Disponent und Fahrer. Dies bezieht sich insbesondere auf die Übermittlung von Auftrags- und Transportdaten, sowie auf Daten, die zur Auftragsfortschrittskontrolle dienen. In dieser Arbeit werden zunächst einige am Markt verfügbare Systeme vorgestellt und mit ihren Vor- und Nachteilen präsentiert. Im Anschluss wird das Kommunikationssystem vorgestellt, das im Rahmen des Forschungsprojekts „Mobile Spedition im Web (SpiW)1“ entwickelt wird. Dieses Kommunikationssystem soll als Zusatzmodul in eine bestehende IT-Infrastruktur eines Speditionsunternehmens eingebunden werden. Da das Kommunikationssystem eine offene Schnittstelle anbietet, kann es mit verschiedenen Speditionslogistiksystemen integriert werden, jedoch wird hier die Unterstützung der Schnittstelle seitens des Speditionslogistiksystems vorausgesetzt. Durch eine spezielle Workflow-Engine kann das Kommunikationssystem leicht an die unterschiedlichen Arbeitsabläufe in verschiedenen Speditionsunternehmen angepasst werden.
89

A Comparison of Manual Signing and PECS Within a Functional Communication Training Context

Boudloche, Lloyd, JR 12 December 2016 (has links)
This applied dissertation study was designed to inform and advance knowledge regarding research in the area of the effectiveness of functional communication training (FCT) in reducing challenging behaviors among individuals with autism spectrum disorder (ASD) who were nonverbal, by using a quantitative single subject approach. The researcher specifically focused on determining which modality, Picture Exchange Communication System (PECS) or manual sign language, would be the most effective as a replacement behavior to bring about a reduction in challenging behaviors. Previous researchers in the field of FCT did not address this area, thus leaving a gap in the research. The participants for the study were three children with ASD between the ages of 4 and 6. Prior to the start of the study, multiple assessments were administered to assess the function of challenging behaviors, level of functioning, imitation skills, and preferences. The intervention phases consisted of randomly alternating between a session of PECS and manual sign daily with each session consisting of 10 trials. Baseline data was collected to assess preexisting skill level to mand for items. The intervention trials continued until the participants reached mastery level in either modality. Results demonstrated that only PECS was effective for both the participants who completed the study, and for the participant who mastered both manual signing and PECS, PECS had a quicker acquisition rate. Implications from the findings suggest that FCT is an effective intervention in reducing challenging behaviors, and that PECS might be more effective for quick reductions of challenging behaviors. The study is a valuable addition to the current FCT research as it aligns with and extends findings from previous research.
90

Advanced Signal Processing for Fiber-Optic Communication Systems Scaling Capacity Beyond 100 Tb/s / 光ファイバ通信システムの100 Tb/s容量限界の克服へ向けた信号処理技術

Shibahara, Kohki 25 September 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第20740号 / 情博第654号 / 新制||情||113(附属図書館) / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 守倉 正博, 教授 大木 英司, 教授 梅野 健 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

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