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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

VECTOR QUANTIZATION USING ODE BASED NEURAL NETWORK WITH VARYING VIGILANCE PARAMETER

Khudhair, Ali Dheyaa 01 May 2012 (has links)
Vector Quantization importance has been increasing and it is becoming a vital element in the process of classification and clustering of different types of information to help in the development of machines learning and decisions making, however the different techniques that implements Vector Quantization have always come short in some aspects. A lot of researchers have turned their heads towards the idea of creating a Vector Quantization mechanism that is fast and can be used to classify data that is rapidly being generated from some source, most of the mechanisms depend on a specific style of neural networks, this research is one of those attempts. One of the dilemmas that this technology faces is the compromise that has to be made between the accuracy of the results and the speed of the classification or quantization process, also the complexity of the suggested algorithms makes it very hard to implement and realize any of them on a hardware that can be used as a fast-online classifier which can keep up with the speed of the information being presented to the system, an example for such information sources would be high speed processors, and computer networks intrusion detection systems. This research focuses on creating a Vector Quantizer using neural networks, the neural network that is used in this study is a novel one and has a unique feature that comes from the fact that it is based solely on a set of ordinary differential equations. The input data will be injected in those equations and the classification would be based on finding the equilibrium points of the system with the presence of those input patterns. The elimination of conditional statements in this neural network would mean that the implementation and the execution of the classification process of this technique would have one single path that can accommodate any value. A single execution path will provide easier algorithm analysis and open the possibility to realizing it on a pure analog circuit that can have an operation speed able to match the speed of incoming information and classify the data in a real time fashion. The details of this dynamical system will be provided in this research, also the shortcomings that we have faced and how we overcame them will be explained in particulars. Also, a drastic change in the way of looking at the speed vs. accuracy compromise has been made and presented in this research, aiming towards creating a technique that can produce accurate results with high speeds.
62

Avaliação da concentração de flúor na água de abastecimento público de Bauru, antes e depois da fluoretação

Irene Ramires 22 October 2004 (has links)
A importância da fluoretação da água de abastecimento público na prevenção da cárie dentária é reconhecida e exaustivamente estudada desde 1945. O objetivo desta pesquisa foi o de avaliar a concentração de flúor presente na água de abastecimento público de Bauru, SP, antes e depois do processo de fluoretação. Para tanto estabeleceu-se um protocolo para a coleta de amostras de água durante três dias de uma semana, a cada três meses, durante as quatro estações do ano. As amostras foram coletas na ETA e nos 27 poços que abastecem a cidade, antes e depois da fluoretação, e em 63 pontos (residências) estabelecidos a partir do mapa onde estão definidos os 19 setores de abastecimento, com a finalidade de coletar amostras em toda a extensão da rede. A análise das amostras foi realizada em duplicata, utilizando-se o eletrodo íon-sensível (Orion 9609), acoplado ao potenciômetro (Procyon, modelo 720), adicionando 1 mL de TISAB II a 1 mL da amostra. A checagem dos resultados da análise das amostras de água foi feita através de nova leitura de 10% das amostras e com uma reprodutibilidade mínima estabelecida em 90%. Não foram observadas variações na concentração do flúor naturalmente presente na água em função da sazonalidade de cada uma das estações do ano. A concentração, das 318 amostras analisadas, variou entre 0,05 e 0,15 mg F/L. Entretanto, a média das concentrações de flúor verificadas nas 297 amostras obtidas na ETA e nos poços após a fluoretação variou entre 0,26 e 6,23 mg F/L e das 697 amostras das residências, entre 0,10 e 0,91 mg F/L. A concentração de flúor presente na água de abastecimento público de Bauru, antes da fluoretação, mostrou-se constante, diferente daquela verificada após a fluoretação, que apresentou grandes oscilações na sua concentração de flúor, indicando que o sistema de abastecimento de Bauru não mantém constantes os níveis de flúor na água. / The importance of public water fluoridation for the prevention of dental caries has been scientifically recognized. The aim of this study was to evaluate the fluoride concentration of the public water supply of Bauru, SP, before and after the fluoridation, in different seasons. It was established a protocol for collecting water samples during 3 days in a week, every 3 months. Samples were collected at the Water Treatment Station and in 27 wells that supply the city, before and after fluoridation. In addition, samples were also collected in 63 points (houses), which were selected from a city map, corresponding to the 19 sections of supply, in order to represent all the distribution system. Samples were analyzed in duplicates, using an ion-sensitive electrode (Orion 9609), coupled to a potentiometer (Procyon, model SA 720), by adding 1 mL of TISAB to 1 mL of the water sample. Repeatability was checked in 10% of the samples and was higher than 90%. No differences in the natural fluoride concentration in water were observed in the four different seasons. However mean fluoride concentrations found in the 297 samples collected in the Water Treatment Station and in the wells after fluoridation varied between 0.26 and 6.23 mg F/L. For the 697 samples collected in the houses, the ranged was from 0.10 to 0.91 mg F/L. Natural fluoride concentration in the water before fluoridation was constant, differently from fluoride concentration in the public water supply after fluoridation, which spanned a wide range. This indicates that the system of supply of Bauru does not maintain constant water fluoride levels.
63

Age and vigilance: The effects of event rate and task pacing

Mohney, Jack D. 01 January 1986 (has links)
No description available.
64

Research on Human-Machine Interfaces of Vigilance Estimation and Robot Control based on Biomedical Signals / 生体信号に基づく覚醒度推定とロボット制御のヒューマン・マシン・インターフェイスに関する研究

Ma, Jiaxin 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18944号 / 工博第3986号 / 新制||工||1614(附属図書館) / 31895 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 松野 文俊, 教授 椹木 哲夫, 教授 富田 直秀 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
65

EFFECTS OF LEADERS ON FOLLOWER GOAL STRIVING PROCESSES: COGNITIVE AND EMOTIONAL SENSEMAKING MECHANISMS

Naidoo, Loren J. January 2005 (has links)
No description available.
66

Revisiting the Vigilance Taxonomy: Are Findings Consistent in a Remote Environment?

Waldfogle, Grace E 01 January 2023 (has links) (PDF)
Previous research has highlighted key taxonomic factors that have been found to influence human performance on vigilance tasks. However, previous literature has focused on research conducted in laboratory settings but has not examined vigilance tasks in remote environments. The present dissertation addresses this gap in the literature by examining human performance on a remote vigilance task, as well as workload and stress associated with the task. Qualitative data were collected to further understand the environment and distractions that participants experienced. Across three experiments, 372 participants were asked to complete a vigilance task and answer surveys pertaining to stress, workload, and ambient distractions. Experiment one manipulated the taxonomic factors of event rate and signal discrimination. Next, experiment two manipulated the taxonomic factors of event rate and source complexity. Finally, experiment three manipulated the taxonomic factors of event rate and task type. Across all three experiments, results identified significant differences in performance for the low and high event rate conditions, which are consistent with previous findings. Furthermore, signal discrimination type, source complexity, and task type (i.e., sensory vs. cognitive) resulted in significant differences between groups on measures of performance. All three experiments reported changes in perceived stress and increases in perceived workload. Ambient distractions, when they occurred, did impact performance, but only for experiment two. Overall, this study provides further support for several facets of the vigilance taxonomy and attempts to understand the impact of remote environments and ambient distractions on vigilance performance. Thus, these findings are advancing our understanding of the vigilance taxonomy and how environmental effects may influence human performance.
67

Effects of Sensory and Cognitive Vigilance Tasks on Cerebral Blood Flow Velocity

Beam, Christina Ashley January 2002 (has links)
No description available.
68

Workload and Stress Measurements in the Study of Sustained Attention

FINOMORE, VICTOR STEVEN, JR. 25 August 2008 (has links)
No description available.
69

A Comparison of Cerebral Hemovelocity and Blood Oxygen Saturation Levels During Vigilance Performance

Funke, Matthew E. January 2009 (has links)
No description available.
70

Neuroergonomic and Stress Dynamics Associated with Spatial Uncertainty During Vigilance Task Performance

Funke, Matthew E. 23 September 2011 (has links)
No description available.

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