The discontinuities play an important role both in design and development stages of many geotechnical engineering projects. Because of that considerable time and capital should be spent to determine discontinuity sets by conventional methods. This thesis present the results of the studies associated with the application of the Remote Sensing (RS) and the development of a methodology in accurately and automatically detecting the discontinuity sets. For detection of the discontinuities, automatic lineament analysis is performed by using high resolution satellite imagery for identification of rock discontinuities. The study area is selected as an Andesite quarry area in G&ouml / lbaSi, Ankara, Turkey. For the high resolution data 8-bit Ikonos Precision Plus with 1 meter resolution orthorectified image is used. The automatic lineament extraction process is carried out with LINE module of PCI Geomatica v8.2. In order to determine the most accurate parameters of LINE, an accuracy assessment is carried out. To be the reference of the output, manual lineament extraction with directional filtering in four principal directions (N-S, E-W, NE-SW, NW-SE) is found to be the most suitable method. For the comparison of automatic lineament extraction and manual lineament extraction processes, LINECOMP program is coded in java environment. With the written code, a location and length based accuracy assessment is carried out. After the accuracy assesssment, final parameters of automatically extracted lineaments for rock discontinuity mapping for the study area are determined. Besides these, field studies carried out in the study area are also taken into consideration.

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Doctor of Philosophy(PhD) / This thesis employs survival analysis framework (Allison, 1984) and the Cox’s hazard model (Cox, 1972) to estimate the probability that a credit rating survives in its current grade at a certain forecast horizon. The Cox’s hazard model resolves some significant drawbacks of the conventional estimation approaches. It allows a rigorous testing of non-Markovian behaviours and time heterogeneity in rating dynamics. It accounts for the changes in risk factors over time, and features the time structure of probability survival estimates. The thesis estimates three stratified Cox’s hazard models, including a proportional hazard model, and two dynamic hazard models which account for the changes in macro-economic conditions, and the passage of survival time over rating durations. The estimation of these stratified Cox’s hazard models for downgrades and upgrades offers improved understanding of the impact of rating history in a static and a dynamic estimation framework. The thesis overcomes the computational challenges involved in forming dynamic probability estimates when the standard proportionality assumption of Cox’s model does not hold and when the data sample includes multiple strata. It is found that the probability of rating migrations is a function of rating history and that rating history is more important than the current rating in determining the probability of a rating change. Switching from a static estimation framework to a dynamic estimation framework does not alter the effect of rating history on the rating migration hazard. It is also found that rating history and the current rating interact with time. As the rating duration extends, the main effects of rating history and current rating variables decay. Accounting for this decay has a substantial impact on the risk of rating transitions. Downgrades are more affected by rating history and time interactions than upgrades. To evaluate the predictive performance of rating history, the Brier score (Brier, 1950) and its covariance decomposition (Yates, 1982) were employed. Tests of forecast accuracy suggest that rating history has some predictive power for future rating changes. The findings suggest that an accurate forecast framework is more likely to be constructed if non-Markovian behaviours and time heterogeneity are incorporated into credit risk models.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Accurate water usage information is very important for municipalities in order to provide accurate billing information for high volume water users. Meter reading are currently obtained by sending a person out to every meter to obtain a manual reading. This is very costly with regards to time and money, and it is also very error prone. In order to improve on this system, an image based telemetry system was developed that can be retrofitted on currently installed bulk water meters. Images of the meter dials are captured and transmitted to a central server where they are further processed and enhanced. Character recognition is performed on the enhanced images in order to extract meter readings. Through tests it was found that characters can be recognised to 100% accuracy for cases which the character recognition software has been trained, and 70% accuracy for cases which is was not trained. Thus, an overall recognition accuracy of 85% was achieved. These results can be improved upon in future work by statistically analysing results and utilizing the inherent heuristic information from the meter dials. Overall the feasibility of the approach was demonstrated and a way forward was indicated. / AFRIKAANSE OPSOMMING: Dit is belangrik vir munisipaliteite om akkurate water verbruikingssyfers te hê sodat hulle akkurate rekeninge aan hoë volume water gebruikers kan stuur. Tans besoek ’n persoon fisies elke meter om meterlesings te verkry. Dit is egter baie oneffektief ten opsigte van tyd en geld. Die metode is ook baie geneig tot foute. Ten einde te verbeter op hierdie stelsel was ’n beeld gebaseerde telemetrie stelsel ontwerp wat geïnstalleer word op huidig geïnstalleerde hoë volume water meters. Beelde van die meters word na ’n sentrale bediener gestuur waar dit verwerk word en die beeld kwaliteit verbeter word. Karakter herkenning sagteware word gebruik om die meter lesings te verkry vanuit die verbeterde beelde. Deur middel van toetse is gevind dat karakters herken kan word tot op 100% graad van akkuraatheid in gevalle waar die karakter herkenning sagteware opgelei is, en 70% akkuraatheid vir gevalle waarvoor dit nie opgelei was nie. Dus was ’n algehele herkennings akkuraatheid van 85% behaal. Hierdie resultate kan verbeter word in die toekoms deur die resultate statisties te analiseer en die inherente heuristieke inligting van die meter syfers te benutting. Ten slotte, in die tesis was die haalbaarheid van die benadering gedemonstreer en ’n weg vorentoe vir toekomstige werk aangedui.

Made available in DSpace on 2015-03-26T13:28:39Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1798304 bytes, checksum: 82fab847755cdc498705bfbc7b11d946 (MD5) Previous issue date: 2007-03-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation had the purpose of evaluating the positional accuracy and representing, spatially, the thematic accuracy in products of imagining systems by using as methodologies the Map Accuracy Standards (MAS), to evaluate the positional accuracy, and a thematic reliability map, to represent the space distribution of errors, in way to present to the user a visual indication of the reliability in the attributions of the labels of each pixel in the image. Also, a study was conducted to verify the behavior of the agreement indexes, which are largely used to evaluate the thematic accuracy, when the variation of the number of informational classes and/or the number of validation patterns or even if there is predominant class among the sample used for validation, among the informational classes. Based on the obtained results, it can conclude that the coming data of the remote sensing have positional accuracy to be used for purpose updating, since they are assisting the established norms for the quality control in the work scale wanted. Regarding thematic accuracy, it could be verified that the behavior of the indexes of thematic accuracy are more affected when it occurs discrepancy among the sample values and that the thematic reliability map seems to be an efficient form to represent the thematic accuracy, because it provides good visual representation of the areas that have low precision inside of the classified image. / A presente dissertação teve como finalidade avaliar a exatidão posicional e representar espacialmente a exatidão temática em produtos de sistemas imageadores, empregando como metodologias o Padrão de Exatidão Cartografia (PEC), para avaliar a exatidão posicional, e um mapa de confiabilidade temático, para representar a distribuição espacial do erro, de forma a apresentar ao usuário uma indicação visual da confiabilidade nas atribuições dos rótulos de cada pixel na imagem. Também foi realizado um estudo para verificar o comportamento dos índices de concordância, amplamente usados para avaliar a exatidão temática, quando da variação do número de classes informacionais e/ou do número de padrões de validação ou mesmo se houver classe predominante entre os valores amostrados, para validação, entre as classes informacionais. Pelos resultados obtidos, pode-se concluir que os dados provenientes do sensoriamento remoto possuem exatidão posicional para serem utilizados para fins de atualização, desde que estejam atendendo às normas estabelecidas para o controle de qualidade na escala de trabalho desejada. Com relação à exatidão temática, pôde-se verificar que o comportamento dos índices de exatidão temática são mais afetados quando ocorre discrepância entre os valores amostrados e que o mapa de confiabilidade temático mostra ser uma forma eficaz para representar a exatidão temática, pois fornece uma boa representação visual das áreas que possuem baixa precisão dentro da imagem classificada.

Monitoring of servers over the network is important to detect anomalies in servers in adatacenter. Systems management software exist which can receive messages from servers on which such anomalies occur. Network monitoring software are often used to periodically poll servers for their hardware health status. A centralized approach to network monitoring ispresented in this thesis, in which a systems management software receives messages from servers, and is polled by a network monitoring software. This thesis examines the reliabilityof a centralized monitoring approach in terms of how accurate its response is, as well as the time it took to respond with the correct hardware health status when polled, when it is affected by varying degrees of traffic through conducting an experiment. The results of the experiment show that the monitoring architecture is accurate when exposed to a level of load which is in line with scalability guidelines as offered by the company developing the systems management software, and that the time it takes for a hardware health status to be poll-able for the majority of the measurements lie within the interval 0 to 15 seconds.

Denna uppsats berör ämnet konkurser och behandlar två olika sätt att förutsäga dessa. Dessa tillvägagångssätt är dels revisorers fortlevnadsvarningar, vilket är det tillvägagångssätt som används idag, och dels beräkning med en konkursprediktionsmodell. Syftet med denna studie är att diskutera möjligheten att förbättra träffsäkerheten hos revisorers fortlevnadsvarningar genom att tillämpa en standardiserad fortlevnadsvarning med hjälp av Z”-modellen. Möjligheten undersöks genom att jämföra träffsäkerheten mellan revisorer och Z”-modellen. För att bedöma lämpligheten hos Z”-modellen kartläggs även faktorer och nyckeltal som påverkar revisorers fortlevnadsbedömningar. Studien är av kvantitativ natur och den använda metoden är en dokumentstudie. Studiens urval är samtliga svenska aktiebolag med inledd konkurs under året 2017 och som vid deras senaste bokslut hade en omsättning överstigande tio miljoner kronor samt hade en revisor. Dessa bolag summerar till 336 stycken. De studerade bolagen underkastades en innehållsanalys av årsredovisningarna och tillhörande revisionsberättelser. Från årsredovisningarna inhämtades de siffror som sedan beräknades med hjälp av Z”-modellen, och från revisionsberättelserna inhämtades revisorernas uttalanden om bolagen. Denna data var grunden till hela analysen där träffsäkerheten i att förutsäga en konkurs jämfördes mellan de två olika tillvägagångssätten; revisorernas fortlevnadsvarningar kontra Z”- modellen. Resultatet visar att Z”-modellen är bättre på att förutsäga konkurser än vad revisorer är. Skillnaden i träffsäkerhet analyserades och förklarades med hjälp av teorier som pekar på att revisorerna och deras subjektiva bedömningar kan medföra bias och en underskattning av ett företags negativa siffror. Z”-modellen är å andra sidan objektiv varför dessa problem ej uppstår, vilket verkar medföra en bättre träffsäkerhet. Resultatet visar även att ett statistiskt signifikant samband finns mellan revisorers fortlevnadsvarningar och Z”-modellen. Detta indikerar att revisorer beaktar liknande nyckeltal som Z”-modellen. En faktor som, av studien att döma, påverkar revisorers träffsäkerhet är revisorns tillhörande revisionsbyrå. Detta förklarades av att de olika byråerna använder olika tumregler. / This paper deals with the subject of bankruptcies and deals with two different ways of predicting these. These approaches are partly the auditor's going concern warnings, which is the approach used today, and partly the calculation by a bankruptcy prediction model. The purpose of this study is to discuss the possibility to improve the accuracy of auditors’ going concern warnings by applying a standardized going concern warning with the help of the Z”-model. The possibility is examined by comparing the accuracy in predicting bankruptcies between auditors’ going concern warnings and the Z”-model. Furthermore, to evaluate the suitability of the model, factors and financial ratios that affects the auditors’ judgements are mapped. The method used was of quantitative nature and was a document study. The sample of the study is all Swedish companies that began bankruptcy during the year of 2017 and had a turnover of more than SEK ten million in the last fiscal year and had an auditor. These companies totaled 336. The companies studied were subjected to a content analysis by analyzing the annual reports and associated audit reports. From the annual reports, the figures were then calculated using the Z”- model, and from the audit reports, the auditors' statements about the companies were obtained. This data was the basis for the whole analysis, where the accuracy of predicting bankruptcy was compared between the two different approaches; Z”-model versus auditors' going concern warnings. The result shows that the Z”-model is better in predicting bankruptcy than the auditors. The difference was analyzed and explained using theories that indicate that the auditors and their subjective assessments may lead to bias and an underestimation of a company's negative figures. The Z”-model, on the other hand, is objective why these problems probably do not occur, which ultimately seems to lead to an overall better accuracy. Furthermore, the result shows that a statistically significant relationship exists between the auditors’ going concern warnings and the Z”-model. This indicates that the auditors asses similar financial ratios as the Z”-model. One factor that seems to affect the auditors’ accuracy is the auditor’s audit firm. This was explained by the different firms’ heuristics.

This master thesis investigates how certain components error margin may affect the accuracy of a IFF monopulse receiver. The IFF monopulse receiver measures the angle of arrival of the incident signal by comparing sum and difference signals created in the receiver. The components of interest are phase shifters and attenuators, where both can give individual and different errors depending on the antenna steering angle. The project is conducted at Saab Aeronautics, based on a receiver in development for the Gripen E aircraft. The results of the thesis generated results showing that the angular accuracy decreases with the increase of steering angle. The angular deviation can for some cases be seen as sufficiently small for the receiver to work properly in the ideal case.

Human movements are remarkably adaptive, such that we are capable of completing movements in a novel environment with similar accuracy to those performed in a typical environment. Our ability to perform in these environments involves accurate processing of sensory feedback for online and offline control. These processes of control have been widely studied for well learned actions, but not for actions in a novel visuomotor environment. In two experiments, we examined control processes underlying reaches when participants were first introduced to a visuomotor rotation (Experiment 1) and then following visuomotor adaptation (Experiment 2). All participants completed 150 reach training trials when (1) a cursor accurately represented their hand motion (i.e., aligned cursor) and (2) a cursor was rotated 45 degrees clockwise relative to their hand motion (i.e., rotated cursor). In Experiment 1, we sought to determine if the control processes underlying movements in typical and novel visuomotor conditions were comparable. Participants (n = 16) received either continuous visual feedback or terminal visual feedback regarding movement endpoint during reach training. Analyses revealed that participants were able to demonstrate similar outcomes (i.e., movement time and endpoint errors) regardless of visual or cursor feedback, but also demonstrated more offline control (i.e., took more time planning and were less consistent in initiating their movements) when reaching with a rotated cursor compared to an aligned cursor, even at the end of training. Together, the results suggest a greater contribution of offline control processes and less effective online corrective processes when reaching in a novel environment compared to when reaching in a typical environment. In attempt to promote online corrective processes, participants (n = 16) in Experiment 2 first completed the training trials with continuous visual feedback and then completed an additional 45 reaches under (1) slow movement time (i.e., Slow MT: 800-1000 ms) and (2) fast movement time (i.e., Fast MT: 400-500ms) constraints. Results showed a shift to online control (i.e., greater endpoint accuracy) when reaching with an aligned and rotated cursor, when sufficiently more time was provided (i.e., Slow MT). Specifically, participants were able to more effectively utilize visual feedback for online control under the Slow MT constraint compared to when reaching quickly (i.e., Fast MT). Together, these experiments demonstrate a flexibility in control processes underlying reaches with rotated visual feedback of the hand. In that reaches first engage in offline control processes during adaptation to a visuomotor rotation, and then shift to online corrective processes following visuomotor adaptation.

L’estimation de l’âge au décès d’individus découverts en contexte médico-légal ou ar-chéologique est un sujet fondamental. La cémentochronologie fondée sur le dépôt annuel de cément acellulaire est une technique parmi les plus performantes dont l’exactitude est appréciée dans de nombreuses publications. Cependant, le manque de standardisation ralentit l’adoption de cette méthode et freine l’étude de la précision qui demeure méconnue tout comme l’impact des conditions taphonomiques sur sa fiabilité. Le premier objectif de ce travail est de mesurer la concordance des estimations effectuées, donc la précision, puis d’évaluer l’exactitude, donc la qualité de l’accord entre l’âge estimé et l’âge chronologique, en appliquant un protocole standardisé et certifié ISO-9001 pour s’affranchir des biais inhérents à la préparation. Le second objectif est d’apprécier l’impact des affections taphonomiques trop souvent négligées. La collecte des données à partir de préparations histologiques dentaires représente une opération coûteuse en temps et constitue un obstacle majeur pour conduire des études cémentochronologiques. Nous nous fixons comme autre objectif d’expérimenter un logiciel de comptage semi-automatique, fruit d’une collaboration entre anthropologues (UTML) et développeurs (FEI Visualization Sciences Group). Pour atteindre ces buts, l’étude porte sur 2000 lames histologiques réalisées à partir de 400 canines. 200 canines sont issues de collections de référence dont l’âge, le sexe, l’intervalle postmortem et la durée d’inhumation des sujets sont connus. Afin d’apprécier l’influence de la taphonomie sur la lisibilité et la précision et d’étudier l’applicabilité de la méthode à du matériel ancien, 200 canines extraites de sujets archéologiques datés entre le XIIe et le XVIIIe siècle sont intégrées à l’étude. Précision et exactitude sont approchées pour chaque classe d’âge et en tenant compte des intervalles post-mortem et des affections taphonomiques, mettant ainsi en évidence une fiabilité qui est fonction de l’âge du sujet, mais aussi de l’état de conservation des tissus. Ce travail vise, sur un échantillon standardisé conséquent, à amener une discussion sur les performances de la cémentochronologie à l’échelle individuelle et populationnelle, à apporter des recommandations et proposer un modèle de prédiction pour minimiser les différences entre âge estimé et âge chronologique. / Age at death estimation is a fundamental component of creating a biological profile in forensic and bioarchaeological contexts. Cementochronology based on annual deposition of acellular cementum is one of the most effective ageing techniques, and its accuracy, i.e. the agreement between estimated age and chronological age, is acknowledged in many publications. However, the lack of standardization slows down the adoption of this method and hinders the evaluation of its precision that remains unknown as well as the impact of taphonomical processes. The first objective of this thesis is to measure the agreement between cementum estimates, i.e. the precision, and then to assess the accuracy through the evaluation of the quality of the accordance between chronological age and estimates based on a standardized and ISO-9001 certified protocol to overcome bias due to sample preparation. The second objective is to gauge the impact of taphonomical effects too often neglected. Counting cementum increments on histological preparations is time-consuming and represents a major difficulty to perform cementochronological studies. Another goal is to experiment a semi-automatic program resulting from a col-laboration between anthropologists (UTML) and software developers (FEI Visualization Sciences Group). To achieve these goals, our study is based on 2000 histological sections from 400 canines. 200 canines are derived from reference collections with documented age, sex, postmortem interval and burial duration. In order to grasp the influence of taphonomy on slices readability and on precision and to investigate the applicability of this method on ancient material, 200 canines extracted from archaeological assemblages dated between the XIIth century and XVIIIth century are included in the study. Accuracy and precision are assessed for each age group in considering post-mortem intervals and taphonomical conditions and show a reliability influenced by age but also by tissue preservation. This work aims, on a large standardized sample, to discuss cementochronology’s performance for individual and population approaches, to provide recommen-dations and to propose a prediction model to reduce differences between estimated age and chronological age.