Embedded systems are present in many fields of application where failure may be critical. Such systems often possess characteristics that hampers the testing activity, as large amount of produced data and temporal requirements which must be specified and evaluated. There are tools that support the development of models for analysis and simulation still in the design stage. After being evaluated, a model may be used as basis to the implementation. In this case, it is important to ensure that the model is consistent with the specification. Otherwise, a divergence will be propagated to the final code. Therefore, the model must be tested prior to the codification. Simulink is a standard development and simulation tool for models of embedded systems. Its wide application in the industry has promoted the creation of free-software alternatives, as XCos. In the literature, there are researches which seek to improve the testing activity for Simulink-like models. The proposed solutions usually focus on test case selection strategies. However, little efforts have been directed to the oracle problem, that is, the difficulty in evaluating if an execution agrees with the specification. The objective of this doctorate proposal is to provide an oracle generation approach for Simulink-like models which addresses the characteristics previously summarized. Specifically, it is proposed a process, methods, procedures and a tool that enable the partially-automated generation of oracles for such models. As a main contribution, it is expected an improvement in the evaluation process of embedded systems in terms of quality, cost and time / Sistemas embarcados estão presentes em diversas áreas de aplicação em que falhas podem ser críticas. Tais sistemas frequentemente possuem características que tornam a fase de teste particularmente desafiadora, como a produção de grande quantidade de dados e requisitos temporais que precisam ser validados de acordo com a especificação. Existem ferramentas que auxiliam no desenvolvimento de modelos para análise e simulação do comportamento de sistemas embarcados ainda na fase de design. Após ser avaliado, o modelo pode ser usado como base para a implementação. Neste caso, deve-se buscar garantir que um modelo esteja de acordo com a especificação. Do contrário, tal divergência será propagada para a implementação. Portanto, e importante que o modelo seja testado antes da fase de implementação. Simulink e uma ferramenta-padrão de desenvolvimento e simulação de modelos de sistemas embarcados. Sua ampla aplicação na indústria incentivou a criação de alternativas de software livres como XCos. Na literatura, existem pesquisas que visam a aprimorar a atividade de teste de modelos Simulink-like. As soluções propostas geralmente focam em estratégias de seleção de casos de teste. Mas pouco esforço tem sido direcionado ao problema do oráculo, isto e, na dificuldade em avaliar se a execução está de acordo com a especificação. O objetivo desta proposta de doutorado é prover uma abordagem de geração de oráculos de teste para modelos simulink-like que contemple as características previamente resumidas. Especificamente, é proposto um processo, métodos, procedimentos e uma ferramenta que viabilizem a geração parcialmente automatizada de oráculos de teste para modelos Simulink-like. Como contribuição principal, é esperada a melhora da qualidade, custo e tempo do processo de validação de sistemas embarcados suportados por modelagem em Simulink e ferramentas similares

Cette thèse s'inscrit dans les domaines de la statistique non-asymptotique et de la théorie statistique de la sélection de modèle. Son objet est la construction de procédures d'estimation de paramètres en régression hétéroscédastique. Ce cadre reçoit un intérêt croissant depuis plusieurs années dans de nombreux champs d'application. Les résultats présentés reposent principalement sur des inégalités de concentration et sont illustrés par des applications à des données simulées.<br /><br />La première partie de cette thèse consiste dans l'étude du problème d'estimation de la moyenne et de la variance d'un vecteur gaussien à coordonnées indépendantes. Nous proposons une méthode de choix de modèle basée sur un critère de vraisemblance pénalisé. Nous validons théoriquement cette approche du point de vue non-asymptotique en prouvant des majorations de type oracle du risque de Kullback de nos estimateurs et des vitesses de convergence uniforme sur les boules de Hölder.<br /><br />Un second problème que nous abordons est l'estimation de la fonction de régression dans un cadre hétéroscédastique à dépendances connues. Nous développons des procédures de sélection de modèle tant sous des hypothèses gaussiennes que sous des conditions de moment. Des inégalités oracles non-asymptotiques sont données pour nos estimateurs ainsi que des propriétés d'adaptativité. Nous appliquons en particulier ces résultats à l'estimation d'une composante dans un modèle de régression additif.

<p>I denna uppsats undersöks hur Kronofogden har byggt upp sin beställarkompetens inför och under upphandlingen av sitt första affärssystem, samt vilken inverkan behovet av beställarkompetens har haft på upphandlingens upplägg.</p><p>Genom att studera den upphandlingsprocess Kronofogden bedrev vid upphandling av nytt affärssystem och med hjälp av en modell för beställarkompetens identifieras vilka faktorer som påverkat upphandlingen samt vilken inverkan dessa faktorer haft.</p><p>Kronofogden har byggt upp sin beställarkompetens genom att utgå ifrån verksamhetens behov och lärt sig hur ett affärssystem kan tillfredsställa behovet. Därigenom har man förbättrat sina möjligheter att genomföra en framgångsrik upphandling trots att Kronofogden inte har några tidigare erfarenheter av affärssystem. Utifrån den förståelse Kronofogden har byggt upp rörande affärssystem har man valt att begränsa sin lösning för att sedan fortsätta successivt och genom att använda ett testsystem har de fått in en extra säkerhet i upphandlingen.</p>

I denna uppsats undersöks hur Kronofogden har byggt upp sin beställarkompetens inför och under upphandlingen av sitt första affärssystem, samt vilken inverkan behovet av beställarkompetens har haft på upphandlingens upplägg. Genom att studera den upphandlingsprocess Kronofogden bedrev vid upphandling av nytt affärssystem och med hjälp av en modell för beställarkompetens identifieras vilka faktorer som påverkat upphandlingen samt vilken inverkan dessa faktorer haft. Kronofogden har byggt upp sin beställarkompetens genom att utgå ifrån verksamhetens behov och lärt sig hur ett affärssystem kan tillfredsställa behovet. Därigenom har man förbättrat sina möjligheter att genomföra en framgångsrik upphandling trots att Kronofogden inte har några tidigare erfarenheter av affärssystem. Utifrån den förståelse Kronofogden har byggt upp rörande affärssystem har man valt att begränsa sin lösning för att sedan fortsätta successivt och genom att använda ett testsystem har de fått in en extra säkerhet i upphandlingen.

Model selection methods and nonparametric estimation of Levy densities are presented. The estimation relies on the properties of Levy processes for small time spans, on the nature of the jumps of the process, and on methods of estimation for spatial Poisson processes. Given a linear space S of possible Levy densities, an asymptotically unbiased estimator for the orthogonal projection of the Levy density onto S is found. It is proved that the expected standard error of the proposed estimator realizes the smallest possible distance between the true Levy density and the linear space S as the frequency of the data increases and as the sampling time period gets longer. Also, we develop data-driven methods to select a model among a collection of models. The method is designed to approximately realize the best trade-off between the error of estimation within the model and the distance between the model and the unknown Levy density. As a result of this approach and of concentration inequalities for Poisson functionals, we obtain Oracles inequalities that guarantee us to reach the best expected error (using projection estimators) up to a constant. Numerical results are presented for the case of histogram estimators and variance Gamma processes. To calibrate parametric models,a nonparametric estimation method with least-squares errors is studied. Comparison with maximum likelihood estimation is provided. On a separate problem, we review the theoretical properties of temepered stable processes, a class of processes with potential great use in Mathematical Finance.

Texte remanié de: Thèse de doctorat--Épigraphie grecque--Paris, EPHE, 2000.

published_or_final_version / Chinese / Doctoral / Doctor of Philosophy

Culture is commonly viewed as the most significant factor that distinguishes one ethic group from another. Writing is primarily defined as the carrier of culture. Religion is generally conceded to be the important way to convey culture, while culture is primly manifested by religion. Shang Dynasty that started up as a very first dynasty boasts of literary inscription, in the same time, it is discovered to be the earliest era of writing system in existence. All that is attributed to the Oracle Bone Inscriptions unearthed. Hence, Oracle Bone Inscriptions is associated with the culture study of Shang Dynasty. Central to the culture of Shang Dynasty is the religion culture in the sense that Oracle Bone Inscriptions articulates a great deal of records related to religion. Oracle Bone Inscriptions, accordingly, manages to provide abundant and genuine documents and evidences for the purpose of studying the culture of Shang Dynasty. The research aims to focus on the Oracle Bone Inscriptions as a main object of analysis, with the combination of the study of Oracle Bone, history of Shang Dynasty together with anthropology, which intends to explore the characteristics of China’s religion and develop a new definition. The Shang Dynasty is regarded as a period of strengthening religious belief and rituals. The degree of China’s religion ceremony represents itself in a statement of full popularity and development in Shang Dynasty which is implicated by the Oracle Bone Inscriptions, and the worship ceremony is embodied in China’s religion. Through the research, it is concluded that the core belief of China’s religion mainly revolves around ancestor worship and its consciousness; particular religious sites, such as ancestor temples; worship ancestor of genetic connection as well as ancestor of social groups; and belief of ethics and morality. Religion is closely concerned in society construction and nation building; moreover, it exerts a significant influence on Chinese cultures in many aspects. / published_or_final_version / Chinese / Master / Master of Philosophy

Kasdieninis žiniatinklio informacinių sistemų (toliau – IS) naudojimas paprastų vartotojų, verslo ir vyriausybinių organizacijų tarpe, reikalauja vis aukštesnės tokių IS kokybės. Žiniatinklio IS dažniausiai yra tokia programinė įranga, kurios sudėtingumas, dėl keleto apjungiamų technologijų, yra aukštas, o pokyčių greitis yra didelis. Vykdant palaikymo ir priežiūros darbus, gali atsirasti begalė klaidų, kurias iššaukia atlikti pakeitimai. Regresinio testavimo paskirtis yra užtikrinti, jog įdiegus programinės įrangos pakeitimus, tokius kaip naujo funkcionalumo pridėjimas ar jau egzistuojančio taisymas, ankstesnėje IS versijoje veikęs funkcionalumas veiks taip pat gerai ir naujojoje versijoje. Šiame darbe tiriami iš HTML žymų sudarytą IS atsaką galintys palyginti regresinio testavimo algoritmai (toliau – testų orakulai). HTML ãtsako kaip teksto lyginimas pateikia per daug klaidingai teigiamų (angl. false positives) rezultatų – testuotojas užverčiamas pranešimais apie netikras klaidas. Mūsų realizuotas testų orakulas HTML žymų atsaką nagrinėja kaip medžio struktūrą. Toks algoritmo veikimas leidžia tikrinti arba netikrinti aprašytas HTML semantines savybes, ko pasekoje yra sumažinamas klaidingai teigiamų ir klaidingai neigiamų rezultatų kiekis. Realizuotas testų orakulas nuo literatūroje aprašomų ir rinkoje siūlomų testų orakulų skiriasi tuo, jog nepraneša apie klaidą, kai HTML atsakas būna papildytas naujomis žymomis, kurios nekeičia pradinės medžio struktūros. Žiniatinklio IS... [toliau žr. visą tekstą] / Common usage of web information systems among consumers, business and governmental organizations require higher quality of such systems. Web information systems is such a software, which has high complexity because of the multiple technology usage and tends to rapid changes. Errors may occur because of the changes that have been made through maintenance period. Regression testing purpose is to ensure, that software changes such as new functionality or previously existed functionality modification, did not affect functionality, which was well working in the older version. In these master thesis we analyze test oracle comparators which can compare HTML response. HTML as a text comparison produces too many false positives. Meanwhile our test oracle comparator analyses HTML response as is was a tree structure. Thus implementation of the test oracle comparator algorithm enables opportunity to validate or not to validate described HTML semantic features. Therefore, we get fewer false positives and false negatives. Our implemented test oracle comparator differs from the ones described in literature or the ones proposed in market by capability not to warn tester about changes such as newly added HTML tag, which do not change overall tree structure. In this way the introduction of natural functionality growth is allowed. After improvement our test oracle comparator detects 90 % errors with the 90 % precision, whereas in the market existing test oracle comparator of the regression... [to full text]

Code faults can seriously degrade scientific software accuracy. Therefore, it is imperative that scientific software developers scrutinize their codes in an attempt to find these faults. This thesis explores, particularly, the efficacy of code testing as a method of scientific software code fault detection. Software engineers, as experts in code quality, have developed many code testing techniques, but many of these techniques cannot readily be applied to scientific codes for at least two reasons. First, scientific software testers do not usually have access to an ideal oracle. Second, scientific software outputs, by nature, can only be judged for accuracy and not correctness. Testing techniques developed under the assumption that these two problems can be ignored--as most have been--are of questionable value to computational scientists. To demonstrate the reality of these problems and to provide an example of how software engineers and scientists can begin to address them, this thesis discusses the development and application of a novel technique: Mutation Sensitivity Testing (MST). MST is based on traditional mutation testing, but--in place of a focus on mutant "killing"--MST focuses on assessing the mutation sensitivity of a test set. In this thesis, MST experiments are conducted using eight small numerical routines, four classes of mutation operators, and 1155 tests. The results are discussed and some conclusions are drawn. Two observations are of particular interest to computational scientists. First, it is found that oracles that exhibit uncertainties greater than (approximately) 80% of the expected output are of questionable value when they are used in the testing of scientific software. Second, it is found that a small number of carefully selected tests may be sufficient to falsify a code. / Thesis (Master, Computing) -- Queen's University, 2009-04-19 13:34:08.943