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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.
91

Σχεδιασμός θερμικού ηλιακού συστήματος για τα μετεωρολογικά δεδομένα της Πάτρας

Ζάρρας, Γεώργιος 18 June 2009 (has links)
Σκοπός της παρούσης διπλωματικής εργασίας είναι η διερεύνηση, μέσω παραμετρικών αναλύσεων, της συμπεριφοράς και απόδοσης ενός δεδομένου Θερμικού Ηλιακού Συστήματος (Θ.Η.Σ.) για την περιοχή της Πάτρας. Στα πλαίσια αυτά, στο πρώτο μέρος της εργασίας περιλαμβάνεται μία βιβλιογραφική έρευνα, η οποία καλύπτει εκτενώς θέματα όπως η ηλιακή ακτινοβολία, κατηγορίες – εφαρμογές και ανάλυση των κύριων συνιστωσών ολοκληρωμένων Θ.Η.Σ., καθώς επίσης και μεθόδους εξομοίωσης τους. Στο δεύτερο μέρος αναπτύσσεται πρόγραμμα υπολογιστή, το οποίο αφ’ ενός υπολογίζει την ηλιακή ακτινοβολία που προσπίπτει σε μία επιφάνεια στην περιοχή της Πάτρας, αφ’ ετέρου προσδιορίζει, μέσω δύο μεθόδων (αναλυτική και f-chart), τα μηνιαία και ετήσια ποσοστά κάλυψης του φορτίου ενός δεδομένου Θ.Η.Σ.. Τα αποτελέσματα των αναλύσεων αυτών εμφανίζονται στη συνέχεια σε σχετικά γραφήματα παρέχοντας διάφορα χρήσιμα συμπεράσματα. / This project includes bibliographic research related to solar thermal systems and a study of performance, via parametrical analysis, for a solar water heating system installed in a hotel unit located in the region of Patras.
92

Nouvelles approches pour la conception d'outils CAO pour le domaine des systèmes embarqués

Lapalme, James January 2009 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal
93

Sparse graph-based coding schemes for continuous phase modulations / Schémas codés pour modulation de phase continue à l'aide de codes définis sur des graphes creux

Benaddi, Tarik 15 December 2015 (has links)
L'utilisation de la modulation à phase continue (CPM) est particulièrement intéressante lorsque le canal de communication comporte une forte non-linéarité et un support spectral limité, en particulier pour la voie aller, lorsque l'on dispose d'un amplificateur par porteuse à bord du satellite, et pour la voie retour où le terminal d'émission travaille à saturation. De nombreuses études ont été effectuées sur le sujet mais les solutions proposées reposent sur la démodulation/décodage itératif des CPM couplées à un code correcteur d'erreur de type convolutif ou bloc. L'utilisation de codes LDPC n'a pas été à ce jour abordée de façon précise. En particulier, il n'existe pas à notre connaissance de travaux sur l'optimisation des codes basés sur des graphes creux adaptés à ce type de schémas. Dans cette étude, nous proposons d'effectuer l'analyse asymptotique et le design d'un schéma Turbo-CPM basé sur des graphes creux. Une étude du récepteur associé comportant les fonctions de démodulation sera également effectuée. / The use of the continuous phase modulation (CPM) is interesting when the channel represents a strong non-linearity and in the case of limited spectral support; particularly for the uplink, where the satellite holds an amplifier per carrier, and for downlinks where the terminal equipment works very close to the saturation region. Numerous studies have been conducted on this issue but the proposed solutions use iterative CPM demodulation/decoding concatenated with convolutional or block error correcting codes. The use of LDPC codes has not yet been introduced. Particularly, no works, to our knowledge, have been done on the optimization of sparse graph-based codes adapted for the context described here. In this study, we propose to perform the asymptotic analysis and the design of turbo-CPM systems based on the optimization of sparse graph-based codes. Moreover, an analysis on the corresponding receiver will be done.
94

Mapeamento geotécnico e análise dos processos erosivos na bacia do córrego Tuncum, São Pedro-SP, escala 1:10.000 / Geotechnical mapping and analysis of erosion process at Tuncum creek watershed, São Pedro-SP, scale: 1:10.000

Aristotelina Ferreira da Silva 17 October 2003 (has links)
Este trabalho procurou analisar os fatores influentes nos processos erosivos na bacia do córrego Tuncum, município de São Pedro-SP, através de características observadas, tanto no campo como em laboratório (ensaios geotécnicos de caracterização de solos e ensaio de erodibilidade), onde se constatou que as áreas que apresentam alta susceptibilidade aos processos erosivos estão associados principalmente ao material geológico constituinte da bacia. Para o estudo da evolução das feições erosivas foram utilizadas fotografias aéreas de três diferentes datas (1972, 1995 e 2000), e com auxílio de técnicas de geoprocessamento realizou-se um tratamento qualificado das informações adquiridas. A análise das informações obtidas permitiu o estabelecimento da susceptibilidade à erosão que associada às informações de uso e ocupação conduziu a definição de prognósticos acerca da evolução dos processos erosivos na área. Os documentos cartográficos elaborados foram o mapa de documentação, mapa de Landforms, carta de declividade, mapa de materiais inconsolidados, carta de susceptibilidade à erosão e carta de prognósticos ao desenvolvimento de erosões lineares. / This work aims to analyze the main factors related to the erosion processes in the Tuncum creek watershed, city of São Pedro-SP, based on the observed geological-geotechnical characteristics in the field and laboratory (soil geotechnical characterization and erodibility tests). It was verified that high susceptibility area to the erosion processes are mainly associated to geological materials of the watershed. For the study of the evolution erosion features were used aerial photographs of three different dates (1972, 1995 and 2000), and with aid of geoprocessing techniques realized a qualified treatment to the acquired informations. The analysis of the obtained informations allowed the establishment of the erosion susceptibility that associated to the information of use and occupation lead the definition of prognostics concerning the evolution of the erosive processes in the area. The cartographic documents elaborated were documentation, landforms and unconsolidated materials maps, declivity, susceptibility to erosion and prognostic to the development of linear erosions charts.
95

Gráficos CUSUM e EWMA para monitorar dados de contagem com distribuição binominal negativa. / CUSUM and EWMA control charts to monitor series of Negative Binomial count data,

Pablo Cezar Urbieta 22 March 2016 (has links)
Gráficos de controle têm sido amplamente utilizados na manufatura para melhoria de processos. Diversas abordagens tem sido propostas para melhorar o desempenho dos gráficos existentes na literatura. Além disso, o uso de gráficos de controle tem se estendido para outras áreas, tais como, economia, finanças, medicina, etc. O objetivo deste trabalho é comparar o gráfico CUSUM com o gráfico EWMA para monitoramento do número diário de internações hospitalares. Para tanto, utilizou-se uma série histórica de internações devido a doenças respiratórias para a população acima de 65 anos. Um modelo linear foi ajustado considerando que o número de internações segue uma distribuição Binomial Negativa. São simulados diversos cenários de mudança no número médio de internações e utilizando diferentes estatísticas baseadas em transformações, é feita uma comparação entre estes gráficos. Verifica-se que o gráfico EWMA com limite de controle assintótico possui desempenho muito similar ao gráfico CUSUM. Já o EWMA implementado com limite de controle exato apresenta melhor desempenho em relação ao gráfico CUSUM quando se atribui pesos menores aos dados atuais. / Control charts have been widely used for process improvement in manufacturing. In literature several approaches have been proposed to improve the current charts performance. In addition, the use of control charts has been extended to other areas such as economics, finance, medicine, and others. The objective of this study is to compare CUSUM control chart with EWMA control chart for monitoring daily number of hospital admissions. Using a historical hospitalizations series due to respiratory diseases for people over 65 years old, a Negative Binomial regression model is fitted. Several scenarios are simulated using different shifts in the mean and using different statistics based on transformations, in order to compare these charts. It is shown that EWMA control chart with asymptotic control limit has similar performance as CUSUM control chart. However, using smaller values for new observations the EWMA control chart with exact control limit has better performance than CUSUM control chart.
96

Určování způsobilosti a stability vybraného technického procesu / Determination of capability and stability of a chosen technical process

Šváchová, Mariana January 2020 (has links)
This diploma thesis deals with the evaluation of the capability of a specific production process. The theoretical part of the work contains a description of statistical process control, types of control charts and evaluation of process capability. The practical part is focused on evaluating the capability of a specific process. The method of dataset collection is described at first, then this data are analyzed and the capability of this process is evaluated.
97

Safety Measures in the Epilepsy Monitoring Unit: An Organizational Assessment

Yates, Tina R. 11 May 2022 (has links)
No description available.
98

Evaluating the use of Brush and Tooltip for Time Series visualizations: A comparative study

Eklund, André, Helin, Sebastian January 2023 (has links)
This study uses a combination of user testing and analysis to evaluate the impact of brush and tooltip on the comprehension of time series visualizations. Employing a sequential mixed-methods approach, with qualitative data from semi-structured interviews used to inform the design of a visualization tool, followed by a quantitative user study to validate it. Sixteen (16) participants from various fields of study, predominantly computer science, participated in the study. A MANOVA test was conducted with results indicating a significant statistical difference between the groups. Results deriving from the study show that the use of brush and tooltip increases user accuracy on detecting outliers, as for perception of trends and patterns. The study’s context was limited to desktop usage, and all participants were treated as a homogenous group, presenting potential limitations in applying these findings to other devices or more diverse user groups. The results provide information about improving time series data visualizations for facilitating more efficient and effective understanding, which can be relevant specifically to data analysts and academic researchers.
99

Storleksstrategier inom svenska modeföretag : och dess påverkan på kunders syn på storlekar och passform / Size strategies within Swedish fashion companies

Byhmer Svensson, Fanny, Gustafsson, Olivia, Tornberg, Ida January 2022 (has links)
Kläder i samma storlek från samma företag kan skilja sig radikalt mot varandra men det kan även skilja sig mellan olika företag. Som konsument kan du beställa samma storlek från två olika företag och motta produkter som skiljer sig stort i upplevd passform. Trots att flertal studier gjorts på storleksstrategin har vi inte kunnat hitta någon studie som kombinerar och ser på helheten av företags storleksstrategi. Därav är studiens syfte att undersöka svenska företags storleksstrategi inom deras damsortimentet och hur en förändrad strategi kan påverka företagets returer. Studien bidrar till en större förståelse för inköpare inom modeindustrin och om hur strategier gällande storleksurval och information till kund gällande storlekar kan komma att påverka företagets returer. Studien kommer också undersöka hur svenska företag storleksstrategier motsvarar kundernas förväntningar på klädernas passform och storlek. För att besvara studiens frågeställning genomfördes semistrukturerade intervjuer med tre svenska modeföretag, samt en en enkätstudie mot kvinnliga konsumenter mellan 20-84 års ålder. Detta för att få en syn på problemet ur både ett företagsperspektiv och ett konsumentperspektiv. De teman som undersökts är prover, måttlista, returandel, förbättrad passform och lönsamhet. Resultatet från fyra intervjuer och 96 enkätsvar visar på att det finns en dissonans mellan företags arbetssätt och konsumenters förväntningar på företagen. Möjlighet till att minska denna dissonans hade varit ifall företagen hade ändrat i sina storleksstrategier genom att alla utgår ifrån samma måttlista och storlekssystem. Vidare att företag implementerar sina mönsterkonstruktioner internt för att motverka variationer i passform på grund av varierande leverantörer. Genom att upprätthålla virtuella provrum för konsumenterna ger det dem chansen att testa plagg online innan köp, vilket hade kunnat eliminera många av de returer som på grund av att man beställer samma plagg i fler än en storlek. Således hade egna mönsterkonstruktioner resulterat i färre returer och påverkat lönsamheten positivt, då företagen hade kunnat erbjuda storlekar och passform som inte beror på val av leverantör. / Clothes of the same size and from the same company, can differ radically from each other. Likewise, the same size and fit can also differ between different companies. A consumer can order the same size and receive products that differ greatly in perceived and actual fit. Although there have been studies made on different parts of companies size strategy, there has not been any study that combines them and looks at the different strategies as a whole. The purpose of this study is therefore to examine the size strategies of Swedish fashion companies’ ladies assortment and whether a change in strategy would affect the returns. Furthermore, this includes whether companies’ size strategies correspond to the customers’ expectations on size and fit. The method was conducted by semi-structured interviews with three different Swedish fashion companies and by a quantitative survey-study towards female consumers above the age of 20. This was made in order to get a perspective on the different size strategies from both companies and consumers. The themes examined throughout this paper are samples, measurement charts, returns, consumers, improved fit and profitability. The result from the four interviews and the 96 survey answers shows that there exists a dissonance between the way companies work and customers’ expectations on sizes and fit that companies offer. Opportunity to reduce this dissonance would have been if all companies changed their size strategies and instead started using the same measurement list och size system. Furthermore, companies could implement their pattern design on the internet to avoid different variations in fit due to the use of different suppliers. Likewise, to maintain virtual test rooms for consumers gives them a chance to test a garment online before purchasing. By offering virtual testing rooms online, it would have been possible to avoid several of the returns that occur due to the need of ordering the same garment in different sizes. Creating their own patterns would result in fewer returns and thus a positive effect on profitability, as the companies should be able to offer sizes and fits that did not depend on their choice of supplier. The report is written in Swedish.
100

Multivariate EWMA Control Chart and Application to a Semiconductor Manufacturing Process

Huh, Ick 09 1900 (has links)
<p>The multivariate cumulative sum (MCUSUM) and the multivariate exponentially weighted moving average (MEWMA) control charts are the two leading methods to monitor a multivariate process. This thesis focuses on the MEWMA control chart. Specifically, using the Markov chain method, we study in detail several aspects of the run length distribution both for the on- and off- target cases. Regarding the on-target run length analysis, we express the probability mass function of the run length distribution, the average run length (ARL), the variance of run length (V RL) and higher moments of the run length distribution in mathematically closed forms. In previous studies, with respect to the off-target performance for the MEWMA control chart, the process mean shift was usually assumed to take place at the beginning of the process. We extend the classical off-target case and introduce a generalization of the probability mass function of the run length distribution, the ARL and the V RL. What Prabhu and Runger (1996) proposed can be derived from our new model. By evaluating the off-target ARL values for the MEWMA control chart, we determine the optimal smoothing parameters by using the partition method that provides an easy algorithm to find the optimal smoothing parameters and study how they respond as the process mean shift time changes. We compare the ARL performance of the MEWMA control chart with that of the multivariate Shewhart control chart to see whether the MEWMA chart is still effective in detecting a small mean shift as the process mean shift time changes. In order to apply the model to semiconductor manufacturing processes, we use a bivariate normal distribution to generate sample data and compare the MEWMA control chart with the multivariate Shewhart control chart to evaluate how the MEWMA control chart behaves when a delayed mean shift happens. We also apply the variation transmission model introduced by Lawless et al. (1999) to the semiconductor manufacturing process and show an extension of the model to make our application to semiconductor manufacturing processes more realistic. All the programming and calculations were done in R</p> / Master of Science (MS)

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