The latest development in the measurement techniques has resulted in fast improvements in the instruments used for measurement of various electrical quantities. A common problem in such instruments is the automation of acquiring, retrieving and controlling the measurements by a computer or a laptop. In this study, nodal resistance measurement (NRM) system is developed to solve the above problem. The purpose of this study is to design and develop a compact electronic board, which measures electrical resistance, and a computer or a laptop controls the board. For the above purpose, surface nodal points are created on the surface of the sample electrically conductive material. The nodal points are connected to the compact electronic board and this board is connected to the computer. The user selects the nodal points, from the computer, between which the NRM system measures the electrical resistance and displays the measured quantity on the computer.

Adults in Hong Kong show relatively low participation in physical activity. In the wake of technological advancements, it has become necessary to promote physical activity in an innovative approach. To that end, this study aimed to investigate the effect of an application of Social Cognitive Theory (SCT) under an eight-week electronic activity monitor system (EAMS)-based intervention on changes in physical activity (PA) as well as its associated SCT constructs of self-efficacy, social support and self-regulation for working adults in Hong Kong. A series of studies were performed: Study 1: In order to assess the validity of the step count output of two popular electronic activity monitor system (EAMS) model, Fitbit Charge HR and Xiaomi Mi Band 2, healthy adult (N=30) worn both EAMS and walked at five predetermined speeds on a treadmill. Two-factor (step x speed) repeated measures ANOVAs was performed to compare the output of devices with manual step count. Result: there was no significant mean difference (p> 0.05) in step count among the Fitbit Charge HR and Mi Band 2 activity monitors and the criterion in all treadmill speeds. Both of them are valid devices for step count in the laboratory setting. Study 2: As to assess the validity of step measurement of Mi Band 2 in the free-living environment, 31 healthy adults were invited for wearing both Mi Band 2 and ActiGraph GT9X Link on their dominant hands wrist for 7 consecutive days. Paired sample t-tests and Pearson correlation were conducted to compare the average steps per day between Mi Band 2 and ActiGraph GT9X Link. Result: there was no significant mean difference (p >0.05) and high positive correlation in step count between the Mi Band 2 and Actigraph. The Mi Band 2 is a valid device for step count in the free-living environment. Study 3: To examine the validity and reliability of the Chinese version of PA related self-efficacy, self-regulation and social support in Hong Kong Chinese adults. There were 230 healthy adults aged 19-63 years recruited. The factorial validity of the scales was assessed by the Confirmatory Factor Analyses (CFA) while criterion validity was assessed by correlating measured constructs with self-reported PA. The internal consistency and scales test-retest reliability were evaluated by Cronbach's alpha and intraclass correlation coefficient, respectively. Result: indicators of CFA supported the one-factor structure while all PA correlates were significant (p<0.01) associated with self-reported PA. All scales demonstrated acceptable internal consistency and test-retest reliability. The results provided psychometric support for using the Chinese version of the scales to measure PA correlates among Hong Kong adults. Main Study: A two-armed randomised controlled trial took place to investigate the effect of an EAMS-SCT intervention on changes in PA and its associated SCT constructs for working adults in Hong Kong. Sixty-four (26 males, 38 females, mean age = 39.98, SD =7.06) participants were stratified based on their job nature and randomly assigned to the control, EAMS only group (n = 33) and the treatment, EAMS-SCT group (n =31) after data screening. Both groups received an EAMS, whereas the EAMS-SCT group received SCT elements in the eight-week intervention, which comprised of one physical activity advisory session conducted by a certified personal trainer and four WhatsApp delivered sessions conducted by the researcher. Outcome measures: Measures of PA (by IPAQ MET score) and SCTs constructs (by the scale of Exercise Self-efficacy, Social Support for Exercise and Physical Activity Self-regulation) of two groups at three times of measurement. 2 x 3 (Group x Time of Measurement) mixed ANOVA and mixed MANOVA were conducted respectively for PA and SCTs constructs for detecting group difference.Results: The interaction effect between different groups (EAMS only and EAMS-SCT) on the participants' score on IPAQ, across three times of measurement (pre-intervention, post-intervention and 4-week follow-up) was significant. The mean IPAQ MET scores of participants in both groups (EAMS only, from 957.64 to 1235.82, EAMS-SCT group from 883.49 to 1420.86) increased and statistically significant difference from its scores than that of the pre-intervention. However, there was no statistically significant difference in IPAQ MET scores between the groups. There was a statistically significant multivariate effect of SCT constructs across the interaction between the groups and time of measurement: F (6, 57) = 7.267, p = .000, with large effect size. Post-hoc analysis revealed that the score of exercise self-efficacy, social support for exercise and physical activity self-regulation from pre- intervention to post-intervention were significantly higher in the EAMS-SCT group. There was no significant difference in the score of physical activity self-regulation between the EAMS only group and the EAMS-SCT group. Meanwhile, there was a significant mean difference in exercise self-efficacy and social support for exercise at Week 8 and social support for exercise at Week 12 between EAMS only and EAMS- SCT group. Conclusion: The participants in the EAMS-SCT group show a significant increase in physical activity level and all three related SCT constructs. Both the EAMS only and the EAMS-SCT groups have an increase in the IPAQ MET score and the score of the scale of physical activity self-regulation after the 8-week intervention. Participants in the EAMS-SCT group exhibit higher scores in the scales of exercise self-efficacy and social support for exercise than participants in the EAMS only group after the 8-week intervention.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Steven Lee Garverick. / M.S.

Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2010. / Static state estimation is a mathematical procedure in which physical measurements from sub-stations and physical model are combined in an optimal way. That is, the measurements obtained from the sub-stations are used with the physical model and the states of the power system are selected or calculated such that the states match the measurements in some best way. The states of a power system are the bus voltage magnitude and voltage angle of each bus of the system. Static state estimation is an increasingly common part of electrical power utility energy management systems (EMS). It plays a critical part in a day-to-day operation of a power system utility. The system measurements obtained from static estimation are used for realtime operations like optimal power flow calculations and contingency analysis. Proper system operations with regards to avoidance of insecure conditions includes situational awareness, therefore, the static estimator plays an important role in power system security. A further motivation: in increasingly electrical power deregulation, more economic operations mean savings for customers and electrical power provider alike. Economic benefit might be realized if system operators have a more accurate situational awareness of the system through improved power system state estimator. The objective of the study was to develop method, algorithm and MATLAB program for solution of power system state estimation using parallel processing techniques. In achieving the objective, the study has concentrated on development of an approximate Tanzanian power system network model comprising of 30 buses and used as a case study; decomposing the bus admittance matrix of the model into 3 interconnected sub-systems; development of mathematical model for real and reactive power injections, real and reactive power flows in the transmission lines and tie-lines connecting the sub-systems; development of measurement data model for voltage magnitude, real and reactive power injections, real and reactive power flows; formulating of a constrained weighted least absolute value state estimation problem; development of decomposition-coordination method and algorithm; and formulating algorithm and MATLAB program for solving the constrained state estimation problem using parallel processing technique.

CAPES / A tomografia por resistência elétrica (ERT) é uma técnica destinada a estimar a distribuição interna de condutividade de um corpo através de medições na periferia. Em aplicações médicas, o objetivo é detectar algum distúrbio de saúde em diferentes diagnósticos comumente utilizados para exames médicos. Em aplicações industriais, a ERT se destina a levantar características internas do objeto para detectar alguma anomalia em variação de alguma grandeza. Uma aplicação industrial notável é a medição de temperatura de gases, porque consegue pode monitorar processos industriais. Neste trabalho, foi proposta uma abordagem alternativa para estimar condutâncias numa rede ou grade de resistências, na qual apenas os elementos periféricos são acessíveis para medições. Diferente das abordagens existentes, onde o meio é considerado contínuo, propõe-se discretizar o meio em elementos de resistência. O princípio de medição baseia-se na injeção de corrente elétrica conhecida em determinados pontos e posterior estimava de todas as condutâncias da rede apenas através medições de tensões periféricas. O sensor para prova de conceito é composto por resistências soldadas entre si. Com o intuito de modelar o comportamento do sensor, foram feitas simulações elétricas. Para validar o desenvolvimento, foi construída uma fonte de corrente e um software onde é possível salvar os dados adquiridos. A montagem completa também inclui uma placa de aquisição de sinais e um algoritmo de reconstrução. Uma vez que a relação entre os valores de condutância e de medição de tensão é não linear, a solução para o problema inverso inclui linearização iterativa, sendo necessário à atualização da matriz de sensibilidade a cada iteração. Possíveis aplicações da técnica desenvolvida incluem qualquer sensoriamento distribuído composto por transdutores que tenha a sua resistência elétrica variada em função de outra grandeza (temperatura, pressão, etc.). As principais vantagens em relação a sensores de temperatura é a capacidade de se desenvolver sensores robustos e a simplicidade de medição. / Electrical Resistance Tomography is a technique aimed at estimating the inner conductivity distribution of a phantom from boundary measurements. In medical applications, the goal is to detect any medical condition. In industrial applications, the objective is to detect any anomalous condition. A notable application is the determination of gas temperature distribution. This work proposes an alternative approach to determine all conductances in a resistor network or grid where only boundary elements are accessible for measurements. Differently from most existing approaches, where the medium is considered continuum, this work proposes to discretize the medium in resistive elements. The basic principle is to inject a known electrical current in certain points and estimate all conductances in the network from only boundary voltage measurements. The proof-of-concept sensor is composed by inter-welded resistors. For modeling purposes, simulations were performed in Proteus. To validate the development, a current source and a LabView software were developed. The complete setup includes a reconstruction algorithm developed in Matlab. Since the relationship between conductance values and voltage measurements is nonlinear, the inverse problem requires an iterative linearization step, where a sensitivity matrix is calculated at each iteration. The main applications of the developed technique include any distributed sensor based on resistive transducers such as temperature, pressure, etc. The advantages of the proposed technique are the ability of design robust sensors as well as the simplicity of measurements.

A Zenith-386 workstation was outfitted with a DICRES-54.8 paralell port board to facilitate I/C between a large Summagrid x-y coordinate digital measurement pad that has a resolution of 10 microns. Film views of high energy particle collisions can be projected onto this pad for measurement. Voice prompts via a Votrax speech synthesis system are sent at critical points during the algorithm from the Z-386 through other ports of the DICRES board. Progress in measurement is fed into the Z-386's serial port from an Interstate voice recognition system at other points of the measurement algorithm. The whole measurement process is managed by an assembler language based modular computer program. / Department of Physics and Astronomy

Les techniques d'évaluation de la composition tissulaire permettent de mieux comprendre les processus physiologiques et leur impact global sur l'état biologique des sujets expérimentaux. Le travail présenté dans ce manuscrit vise à concevoir un système de mesure intégré de spectroscopie de bioimpédance capable de mesurer un large champ de biomarqueurs sur de longues périodes (jusqu'à un an). Le système de mesure présenté peut être utilisé pour des applications de suivi à long terme de variables physiologiques en général. Néanmoins, les solutions présentées visent en particulier le poisson dans le cadre du projet POPSTAR qui vise à améliorer notre compréhension du comportement des poissons en analysant non seulement l’environnement dans lequel les poissons se déplacent et vivent mais aussi les poissons eux-mêmes. Après avoir identifié les défis de conception d'un système de mesure intégré par spectroscopie de bioimpédance, nous avons proposé une nouvelle architecture hybride permettant une spectroscopie rapide tout en maximisant la précision des mesures. Les blocs de génération du signal d'excitation sont critiques car leurs performances affectent l'ensemble des performances de l'architecture. La deuxième partie de cette recherche porte donc sur la conception et l’optimisation de la partie génération de l’architecture. En effet, nous avons amélioré la qualité des signaux de génération de stimuli pour les excitations mono-fréquentielle et multi-fréquentielle tout en proposant pour cela des implémentations sur puce de basse complexité. Dans la dernière partie de notre travail, la source de courant analogique qui transforme les stimuli en un courant d'excitation est discuté. Pour ce bloc, nous avons proposé une nouvelle topologie analogique utilisant un version améliorée du cascode régulé et une compensation de rétroaction du mode commun indépendante des variations du processus. Le premier prototype de puce intégrée embarquant les blocs critiques de l'architecture de mesure de bioimpédance a été conçu et simulé avec un process CMOS 0.18 µm de AMS fonctionnant sous une tension d'alimentation de 1.8 V. / Tissue composition assessment techniques are used to help better comprehend physiological processes and their overall impact on the biological state of the experiments subjects. The research presented in this manuscript aims to design a bioimpedance spectroscopy integrated measurement system capable of measuring a wide range of biomarkers over long periods of time (up to one year). The presented measurement system can be used for physiological variables long time monitoring applications in general. Nevertheless, the presented solutions target in particular fish species in the context of the POPSTAR project which aims to enhance our understanding of fish behavior by analyzing not only the environment in which fish travel and live but also the fish themselves. After identifying the design challenges of a bioimpedance spectroscopy integrated measurement system, we have proposed a novel hybrid architecture providing fast bioimpedance spectroscopy while maximizing the measurement precision. As the signal generation blocks are critical and their performances affect the whole architecture performances. The second part of this research focuses on the design and optimization of the signal generation part of the architecture. Indeed, we have enhanced the stimuli generation signals quality for single tone and multitone excitations while proposing for this blocks low complexity on-chip implementations. In the last part of our work the current driver that transforms the voltage stimuli into an excitation current is discussed. A novel analog topology using an improved regulated cascode and a common-mode feedback compensation independent of process variations is presented. The first chip prototype implementing the critical blocks of the bioimpedance integrated measurement architecture has been designed and simulated in a 0.18 µm AMS (Austria MicroSystems) CMOS process operating at 1.8 V power supply.

[pt] Nesta dissertação, é apresentado um procedimento estatístico para a estimação de perfis de curvas de carga por aparelhos para consumidores residenciais atendidos na BT (Baixa Tensão). O modelo desenvolvido utiliza informações de duas fontes distintas: PPHs (Pesquisas de Posses e Hábitos de Aparelhos Elétricos) e Medições de consumo com medidores eletrônicos com memória de massa que gravam leituras de consumo por aparelhos a cada 15 minutos. Através das PPHs desenvolvidas por Procel/Eletrobrás em 1996, obtêm-se um perfil aproximado da curva de carga do domicilio por aparelho. Entretanto, esta curva tende a ser imprecisa, pois é obtida por declarações de uso dos aparelhos. Para reduzir esta imprecisão, foi montado um experimento onde uma sub-amostra de domicílios auditados pelas PPHs, teve os principais aparelhos da residência medidos por medidores eletrônicos em intervalos de 15 minutos. A partir das curvas de utilização destes aparelhos, obtidas pelos dois procedimentos, utilizou-se um modelo estatístico de regressão linear para estimar coeficientes de ajustes para correção das curvas declaradas para cada hora do dia, para os principais eletrodomésticos do domicílio. Os resultados foram aplicados a duas distribuidoras do grupo ENDESA: AMPLA e COELCE. / [en] In this thesis, it is presented a statistical based model that allows the estimation of the load shape curve for appliances (end uses) for residential consumers that belong to low voltage group (BT clients), using information from two sources: PPHs (Energy Audit on Ownership and Usage of Electrical Appliances) and household measurements through specific devices that provide not only the total consumption (15 minute intervals) as well as the breakdown of this consumption for each device (end use) existing in the household. Through energy audits (PPHs) developed by Procel/Eletrobrás in 1996, one has a rough idea of the load shape curves by appliance. However, the curves obtained this way tend to be rather imprecise, as they are obtained by the consumer information of usage of the equipments on the surveys, which tend to be rather vague. In order to reduce such imprecision, an experiment was set where a subsample of the original survey sample is selected and the main appliances consumption measured by electronic meters at intervals of 15 minutes. The end use load shape obtained by these meters are then compared with the corresponding curve obtained by usage declaration. Using the linear regression model, the correction coefficients of the declarations are obtained for each hour of the day, for the main appliances. The results were applied to two distribution utilities of the ENDESA group: AMPLA and COELCE.

[pt] As perdas de energia elétrica, particularmente as comerciais, constituem problema importante e complexo para as empresas distribuidoras. O problema só se apresenta de forma aguda nos países em desenvolvimento, onde o percentual de perdas por furto é elevado e adquire importantes conotações sociais, políticas e culturais. Isso explica o fato de empresas brasileiras de distribuição de energia elétrica investirem recursos apreciáveis para mitigar esse problema e ressalta a importância de um tema ainda pouco explorado na literatura técnico-científica. Esta dissertação, de caráter exploratório, tem como objetivo estudar o problema de perda de energia por desvio e a eficácia de soluções tecnológicas investigando o caso de uma empresa e os resultados obtidos em projeto recente. Ao tempo do estudo, a empresa implantava uma tecnologia cujo objetivo principal era identificar os clientes que desviam energia elétrica e, posteriormente, tornar o processo de faturamento automatizado. O estudo partiu de algumas questões julgadas mais relevantes, incluindo: Quanto a empresa ganhou com a instalação desta tecnologia? Como se comporta o consumo dos clientes antes e depois da instalação da tecnologia? Há correlação entre o ganho da empresa e o poder aquisitivo da população da área? Há efeito demonstração de uma área sobre suas vizinhas? A partir destas questões foram analisadas séries de dados referentes ao consumo medido antes e após a instalação da nova tecnologia. Os resultados indicam a viabilidade da tecnologia como eficaz paliativo de curto-prazo para o problema cuja solução definitiva envolve tratamento concomitante dos aspectos sociais, políticos e culturais. / [en] Electrical energy losses, chiefly, commercial losses, constitute an important and complex problem for energy distribution companies worldwide. However, only in developing countries the problem becomes acute because theft losses are large, and coupled with social, legal, political and cultural issues. This explains why Brazilian energy distribution companies dedicate sizable investments for mitigating the problem, and stresses the importance of a theme still largely unexplored in the technical-scientific literature. This thesis, of exploratory nature, addresses the problem and assesses the effectiveness of technological solutions by investigating the case of a recent project developed in a Brazilian company. At the time of the research, the company was implementing a new and original technology, whose main objective was to identify pilfering clients, and later on, to make the billing process more automated. The study started with some questions judged more relevant, including: How large was the gain yielded by the new technology? How does the energy consumption behave after the technological change? Is there a correlation between the gain obtained and the areas of lesser purchasing power? Is there a demonstration effect upon neighboring areas? Starting from these questions, series of historical data on measured consumption before and after the new technology were analyzed. The results indicate the feasibility of the technology as an effective shortterm palliative for the problem whose ultimate solution involves the concurrent treatment of the social, legal, political e cultural aspects.