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L’imagerie chimique Raman appliquée à l’analyse des produits pharmaceutiques falsifiés / Raman chemical imaging for the analysis of falsified pharmaceuticalsRebiere, Hervé 28 November 2017 (has links)
La thèse propose une méthodologie d’analyse rapide basée sur l’étude de l’image hyperspectrale Raman d’un produit pharmaceutique falsifié sous forme solide afin, d’une part d’identifier les substances présentes, et d’autre part estimer la teneur du principe actif dans l’échantillon sans étalonnage préalable.La présence de produits pharmaceutiques falsifiés est un véritable enjeu de santé publique. Ce type de produits de santé est facilement disponible sur internet, et beaucoup d’exemples montrent leur dangerosité. De nombreuses techniques sont disponibles pour analyser ces produits et ainsi participer à la lutte contre la falsification de médicament. La combinaison de ces techniques analytiques permet une caractérisation approfondie de l’échantillon. Cependant, peu de techniques analytiques procurent l’ensemble des informations chimiques.L’imagerie chimique Raman est une technique qui répond aux exigences requises pour l’analyse de produits falsifiés sous forme solide. En effet, cette technique peu destructive permet de réutiliser l’échantillon pour des analyses complémentaires. L’imagerie chimique Raman combine les trois disciplines de spectroscopie Raman, microscopie et chimiométrie. Cette technique réalise des mesures successives de spectres Raman sur des zones adjacentes couvrant la surface de l’échantillon. Elle intègre donc des informations spatiales et spectrales. Les méthodes chimiométriques dites de résolution (MCR-ALS et DCLS) analysent le jeu de spectres pour extraire des informations qualitatives (détection des spectres purs du mélange) et des informations quantitatives (estimation de la concentration de la substance active). La méthodologie a été optimisée et validée avec des échantillons préparés en laboratoire, puis appliquée à des échantillons réels authentiques et falsifiés. La sensibilité de la méthode qualitative a été démontrée par la détection d’un principe actif antibiotique à la teneur de 0,3% m/m dans un comprimé à visée anabolisante. De plus la méthode a été capable de détecter les substances utilisées pour le traitement de dysfonctions sexuelles (sildénafil, tadalafil, vardénafil, dapoxétine). Malgré une forte émission de fluorescence, la méthode a réussi à discriminer les 3 sels de clopidogrel (hydrogénosulfate, bésilate et chlorhydrate). L’analyse quantitative directe sur des échantillons de Viagra® et de Plavix® a été jugée convenable avec une déviation de la teneur entre -15% et +24%. Cette déviation est considérée acceptable pour évaluer le risque sanitaire pour le patient et alerter les autorités de santé.Dans le cadre de l’analyse des produits falsifiés, il a été démontré que la micro-spectroscopie Raman associée aux méthodes chimiométriques permet de réaliser un « screening spectroscopique » des composants de l’échantillon, d’identifier les substances chimiques, de visualiser leur distribution sur la surface de l’échantillon et d’estimer leur teneur par « quantification directe ». / The thesis proposes a rapid methodology of analysis based on the Raman hyperspectral image study of a solid form falsified pharmaceutical product in order to identify the substances in the sample and to estimate the content of the active ingredient in the sample without prior calibration.The presence of falsified pharmaceuticals is a real public health issue. This type of products is easily available on the internet, and many examples show their dangerousness. Many techniques are available for the analysis of these products and thus participate in the fight against drug falsification. The combination of these analytical techniques allows a comprehensive characterization of the sample. However few analytical techniques provide all the chemical information. Raman chemical imaging is a technique that meets the requirements for the analysis of falsified products in solid form. Indeed, this non-destructive technique makes it possible the reuse of the sample for additional testing. Raman chemical imaging combines the three disciplines of Raman spectroscopy, microscopy and chemometrics. This technique performs successive measurements of Raman spectra on adjacent location covering the surface of the sample. It therefore collects spatial and spectral information. The so-called resolution chemometric methods analyse the set of spectra in order to extract qualitative information (detection of pure spectra in the mixture) and quantitative information (estimate of the concentration of the chemical substance). The methodology was optimized and validated with samples prepared in the laboratory, and then applied to genuine and falsified real samples. The sensitivity of the qualitative method was demonstrated with the detection of an antibiotic active ingredient at a content of 0.3% m/m in an anabolic tablet. Moreover, the method was able to distinguish substances used for the treatment of sexual dysfunctions (sildenafil, tadalafil, vardenafil, dapoxetine). Despite a high fluorescence emission, the method successfully discriminated the 3 salts of clopidogrel (hydrogen sulfate, besylate and hydrochloride). Direct quantitative analysis of samples of Viagra® and Plavix® was found to be appropriate with a deviation between -15% and +24%. This deviation is considered acceptable to assess the health risk to the patient and to alert health authorities.For the analysis of falsified products, it has been demonstrated that Raman micro-spectroscopy combined with chemometric methods allows to perform a "spectroscopic screening" of the components in the sample, to identify chemical substances, to visualize their distribution on the sample surface and to estimate their content by "direct quantification".
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Žinojimo augimo problema Lakatoso ir Kuhno mokslo filosofijoje / The Growth of Knowledge in the philosophy of science of Lakatos and KuhnKasputis, Juozas 16 June 2011 (has links)
Darbe pristatoma žinojimo augimo problema mokslo filosofijoje, pasirinkus Lakatoso ir Kuhno diskusiją šiuo klausimu. Lakatosas yra vienas iš žymiausių falsifikacionistų, labai prisidėjęs prie Popperio teorijų falsifikavimo metodologijos tobulinimo. Žinojimo augimas yra pagrindinė falsifikacionizmo koncepcija. Falsifikacija Kuhnui yra nepriimtina. Įvykus mokslo revoliucijai, senas žinojimas atmetamas. Nauja paradigma kaupia naują žinojimą. / The discussion between Lakatos and Kuhn is chosen to represent the growth of knowledge in philosophy of science. Lakatos is one of the best-known falsificationists, he improved Popper's methodology of falsification. The growth of knowledge is a key concept in falsificationism. Kuhn did not reject the growth of knowledge, but he had different approach to it. During scientific revolution old knowledge is abolished. There is no continuity from the old paradigm to the new one.
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Švietimo falsifikacija: fenomeno samprata ir situacijos analizė / Falsification of Education:the Conception of Phenomenon and Analysis of SituationAleknaitė, Aušra 22 June 2006 (has links)
Aleknaitė A. Falsification of Education:the Conception of Phenomenon and Analysis of Situation.
Topicality . The reform of educational system in Lithuania requires to estimate the quality of the process of education. Educational establishments participate in international projects and seek the latest methods of cognition, evaluation and diagnostics. Where the quality is concerned we find out a new method like an educational falsification . What does it mean ? There is a lack of scientific research about the phenomenon ‘s content, and the influence to society.
Object. The phenomenon of educational falsification .
Aim. To analyse the concept and situation of educational falsification .
Goals. To investigate educational documents and scientific literature sources, reveal the concept and teachers ‘outlook to educational falsification.
Methodology .With the intention of gathering new educational data there is a provision that old problems become irrelevant meanwhile the new attitude is of greater importance.
The research was conducted in two stages. The first stage included an expert survey and was fulfilled in December, 2005/ February,2006. The group was made of the following experts : educationists, representatives from educational department, high schools and the Seimas. The competence is the main criteria. A hundred teachers were interviewed on the second stage. The research was carried out in Radviliskis comprehensive schools in March, 2006.
The research... [to full text]
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Autenticita potravin na českém trhu / Authenticity of food on the Czech marketLÍBALOVÁ, Renata January 2016 (has links)
The Thesis acquaints consumers with Czech and European legislation regarding food quality and safety. There are also described in detail the supervisory autorities for food authenticity operating in Czech Republic and related terms such as food quality and safety. The following is a pivotal part dedicated to the food authenticity, which describes the problem of food adulteration, including the reasons and methods of food adulteration. The practical part contains the results of inspections of food by SZPI for the year 2015. The analysis of the data is based on the website "Potraviny na pranýři". Another part relates to the evaluation of questionnaire, which focuses on consumers's relationship to authenticity and adulteration of food on the Czech market. The practical part is concludes by the evaluation of set hypotheses.
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Pour une didactique de la conception. Les étudiants en design et les formes d'énonciation de la conception / For design didactics. Design students and the forms of design statementTortochot, Éric 30 March 2012 (has links)
L'activité de conception peut être analysée grâce aux signes produits par les sujets concepteurs et par le discours qu'ils tiennent sur les nouveaux modèles d'artéfacts désirés qui en résultent. L'analyse psycho-sémiologique de l'activité d'étudiants en Master professionnel de design montre deux processus. D'une part, pour résoudre les problèmes abordés, les étudiants rendent compte seuls régulièrement de leur activité en énonçant par divers instruments de représentations les différentes tâches accomplies. D'autre part, pour élaborer les différents modèles d'artéfacts, ils falsifient les contraintes que les enseignants leurs imposent plus ou moins avec insistance. Parce qu'ils communiquent sur le travail qu'ils réalisent et parce qu'ils dialoguent avec des interlocuteurs, les étudiants prennent conscience de l'activité de conception en train de se faire. C'est aussi de cette façon qu'ils organisent des métaconnaissances, des valeurs, des habiletés, c'est-à-dire une compétence de conception. Cette compétence est fondée non pas seulement sur la reproduction d'héritages conceptuels et méthodologiques, sur des routines ou sur des habitudes, mais sur de véritables dispositions à remettre en cause les héritages par des stratégies opportunistes. Réfléchir sur une didactique de la conception, c'est retenir que les étudiants constituent eux-mêmes, aidés par les enseignants, un renouvellement de l'activité professionnelle de conception. Cette thèse tente de montrer qu'une didactique de la conception, afin d'être formalisée, doit prendre en compte le processus d'énonciation comme activité cognitive indispensable à l'acquisition d'une compétence de conception. / Design activity can be analyzed through the signs produced by design developers and their discourse on the new models of artifacts they wished to develop. Psycho-semiotic analysis of student activity in Professional Master of Design shows two processes. First, to solve problems, students report regularly and alone their activities with statements of the different tasks using various representation instruments. Second, to develop different models of artifacts, they falsify the constraints the teachers required with more or less insistence. As students communicate about their work and interact with many people they become aware of their ongoing design activity and organize metaknowledge, values, skills, meaning design abilities. All these acquired abilities are not only based upon the reproduction of conceptual and methodological legacies, routines or habits, but on real inclinations to challenge these legacies using opportunistic strategies. To think about design didactics allows us to understand that students, assisted by teachers, induce themselves a renewal of the design activity. This thesis is an attempt to show that a design didactics, to be formalized, requires taking into account the statement process as an essential cognitive activity for the acquisition of design skills.
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Detecção de adulteração de combustíveis com sensores poliméricos eletrodepositados e redes neurais artificiais. / Fuel adulteration detection using electrodepositated polymer sensors and artificial neural networks.Ozaki, Sérgio Tonzar Ristori 11 June 2010 (has links)
A adulteração de combustíveis é uma grande preocupação no Brasil. A agência reguladora nacional (ANP) detecta anualmente de 1 a 3% de adulterações nas amostras coletadas, o que é um índice alto considerando o tamanho do mercado brasileiro. As alternativas de adulteração são vastas e muito dinâmicas, por isso os arranjos de sensores baseados no conceito de seletividade global parecem os mais adequados para detectar falsificação de combustíveis. O conceito de seletividade global leva em conta a sensibilidade cruzada de sensores químicos não específicos e o uso de métodos de análise multivariada de dados para encontrar padrões para amostras de diferentes composições químicas. Os sensores químicos podem ser obtidos de uma variedade de materiais sensoativos, cujas respostas elétricas variam de acordo com as propriedades físico-químicas do meio em que se encontra. Os polímeros condutores são excelentes materiais sensoativos, pois sua condutividade elétrica é grandemente influenciada pelas condições ambientais e podem ser processados na forma de filmes finos através várias técnicas. No presente trabalho, filmes de poli(3-metiltiofeno) (PMTh) e poli(3-hexiltiofeno) são depositados por cronopotenciometria e cronoamperometria sobre microeletrodos interdigitados e são caracterizados por espectroscopia de impedância. Os dados são analisados por redes neurais artificiais do tipo multilayer perceptron e bons resultados são obtidos na detecção de adulteração de gasolina. O mesmo estudo também pode ser aplicado na detecção de adulteração de álcool etílico combustível com um desempenho um pouco pior. / Fuel adulteration is a major concern in Brazil. The local governmental agency detects from 1 to 3% of problematic samples yearly, which is a lot considering Brazils market size. The myriad of adulteration possibilities is vast and it is very dynamic, thus array of sensors based on global selectivity concept seems to be more suitable methodology to detect problems in fuel. The global selectivity concept encompasses the cross-sensitivity of non-specific chemical sensors and the use of multivariated data analysis methods as a way to provide fingerprints for samples of different chemical composition. The chemical sensors can employ different types of sensoactive materials, whose electrical responses are dependent on the physicochemical characteristics of the media they get in contact with. Conducting polymers (CP) are per excellence suitable sensoactive materials, since their electrical conductivity is highly influenced by the environmental conditions and they can be easily processed in the thin film form by different techniques. In the present work films of poly(3-methylthiophene) (PMTh) and poly(3-hexylthiophene) (PHTh) are deposited by chronopotenciometry and chronoamperometry onto interdigitated microelectrodes and characterized through Impedance Spectroscopy. This data was analyzed with Multilayer perceptron neural networks and a very good performance is found in gasoline adulteration detection. A less great performance was also achieved in the investigation vehicular ethanol adulteration.
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Une analyse économique et expérimentale de la fraude à l'assurance et de l'auditBorgi, Sameh 05 October 2006 (has links) (PDF)
Ce travail propose une approche expérimentale de la fraude à l'assurance. Nous présentons d'abord les deux principaux paradigmes qui ont été développés dans la littérature économique pour analyser la fraude à l'assurance d'un point de vue théorique : les mécanismes de vérification coûteuse et les mécanismes de falsification coûteuse. Selon l'hypothèse de vérification coûteuse, l'assureur vérifie les déclarations de dommages en supportant un coût d'audit. Cette procédure peut être déterministe ou aléatoire. Selon l'hypothèse de falsification, c'est l'assuré qui engage certains frais visant à rendre l'audit imparfait. L'assureur est, par conséquent, incapable de détecter la fraude avec certitude. Parallèlement à cette modélisation, l'expérimentation menée dans ces contextes, confirme que l'audit aléatoire domine l'audit déterministe et que l'application d'une sanction sévère permet de dissuader la fraude, d'atténuer l'ampleur de la falsification et de compenser la mauvaise qualité de l'audit.
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Vetenskap eller pseudovetenskap? : En utvärdering av giltigheten i Poppers kritik gentemot Freuds psykoanalytiska teori på basis av demarkationskriterietBergquist, Linda January 2008 (has links)
<p>In this essay I evaluate the legality of Karl Popper’s criticism against psychoanalysis, regarding this theory of Freud’s being pseudoscientific. Popper’s criticism is based on his theory of demarcation in which he states that an empirical theory must be possible to test by observations in order to be, as most important is, hypothetically possible to falsify based on other empirical statements – often in the form of new found facts that contradict the original statement/theory. In purpose of assessing Popper’s criticism I perform a modified idea analysis, based on a book by Evert Vedung (1977). By referring both to Popper and to spokespersons of psychoanalysis I structure the arguments pro and contra Popper’s criticism, in order to then weigh these arguments against each other. My main conclusion is that psychoanalysis, regardless of Popper’s criticism, is in fact an empirical theory since it can be internally validated based on the observations made by a psychoanalyst. But according to the theory of demarcation psychoanalysis can not be tested based on observations, probably because Popper by ”observations” meant only those that can be made and validated by independent scientists.</p>
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Formal Requirements-Driven Analysis of Cyber Physical SystemsJanuary 2017 (has links)
abstract: Testing and Verification of Cyber-Physical Systems (CPS) is a challenging problem. The challenge arises as a result of the complex interactions between the components of these systems: the digital control, and the physical environment. Furthermore, the software complexity that governs the high-level control logic in these systems is increasing day by day. As a result, in recent years, both the academic community and the industry have been heavily invested in developing tools and methodologies for the development of safety-critical systems. One scalable approach in testing and verification of these systems is through guided system simulation using stochastic optimization techniques. The goal of the stochastic optimizer is to find system behavior that does not meet the intended specifications.
In this dissertation, three methods that facilitate the testing and verification process for CPS are presented:
1. A graphical formalism and tool which enables the elicitation of formal requirements. To evaluate the performance of the tool, a usability study is conducted.
2. A parameter mining method to infer, analyze, and visually represent falsifying ranges for parametrized system specifications.
3. A notion of conformance between a CPS model and implementation along with a testing framework.
The methods are evaluated over high-fidelity case studies from the industry. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2017
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Sistema biométrico híbrido para verificação de assinaturas manuscritas / Hybrid biometric handwritten signature verification systemZimmer, Alessandro 18 August 2018 (has links)
Orientador: Lee Luan Ling / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T06:12:12Z (GMT). No. of bitstreams: 1
Zimmer_Alessandro_D.pdf: 5470836 bytes, checksum: d921f7565d292e8ab4908c12ab13e3ce (MD5)
Previous issue date: 2008 / Resumo: Com este documento é descrito o desenvolvimento de um novo sistema de verificação de assinaturas híbrido on/off-line, em que os dados dinâmicos de referência são adquiridos a partir de um dispositivo especial de entrada de dados e servem de suporte ao sinal estático (imagem) correspondente. As assinaturas são segmentadas segundo a complexidade de seus traços constituintes, baseando-se em um modelo psicofísico delta-lognormal de reprodução da escrita manuscrita. Focos de atenção na imagem (janelas) são gerados e a partir de tais regiões um envelope estático personalizado composto pelos traços simples das assinaturas de um dado escritor é criado. Tal invólucro visa a focalizar a extração das primitivas locais, obtidas a partir de estimadores da estatística de dados direcionais aplicados sobre funções de distribuição de probabilidade extraídas da imagem e do esqueleto interpolado. Primitivas representando a distribuição espacial dos pixels também são calculadas. O envelope protótipo representativo da classe é gerado com os respectivos limiares de decisão durante a fase de aprendizagem através de um critério de minimização da distância intraclasse e delimita através de sua forma o escopo usado para a extração das primitivas locais. Características globais são extraídas, complementando o rol das primitivas utilizadas. Durante o processo de verificação uma imagem é apresentada ao sistema juntamente com o seu número de identificação. O envelope protótipo correspondente à assinatura original é lido da base de dados e superposto à imagem de teste. As primitivas são obtidas e a decisão sobre a autenticidade da assinatura é tomada baseando-se em um classificador limiarizado a voto. Tal projeto é essencialmente inovador pois procura conciliar vantagens das duas correntes existentes na área de verificação de assinaturas (on-line e off-line). Ao contrário dos sistemas puramente on-line, que apresentam de uma forma geral índice de desempenho superior mas que ao mesmo tempo são de aplicação limitada, um sistema híbrido tem aplicação direta no meio bancário e cartorário em que a aquisição supervisionada dos exemplares de referência pode ser solicitada sem maiores dificuldades e a verificação feita a posteriori sem a presença necessária do autor da firma. Também original é o conceito de criação de um envelope estático gerado automaticamente segundo critérios estabelecidos por um modelo de reprodução da escrita manuscrita, bem como a sua personalização por protótipos visando à redução da distância intraclasse / Abstract: Through this document the development of a new hybrid on/off-line signature verification system is described, where the dynamic reference data is acquired by either a tablet or an instrumented pen and it is used to support the corresponding static signal (image). The signatures are segmented according to the complexity of their constituent strokes based upon a delta-lognormal psychophysical handwritten reproduction scheme. Foci of attention in the image (windows) are generated and from those regions a personalized static envelope is created. Such envelope helps in localizing the extraction of the local features, obtained through circular data statistics applied over directional probability distribution functions which are extracted from the image and from the interpolated skeleton. Other measures representing the spatial distribution of pixels are also used. The class representative envelope prototype is generated with the respective decision thresholds during the learning stage through an inter-class minimization criterion and its boundaries spatially limit the extraction of local features. Global features are also used, complementing the group of characteristics thence extracted. During the verification process an image is presented to the system with its identification key. The corresponding prototype envelope of the original signature is then read from the database and placed over the test image. The features are obtained and the decision about the authenticity of the specimen is made by a threshold classifier. Such project is original in its essence, since it tries to conciliate advantages of both signature verification methodologies (on-line and off-line). Differently from purely on-line systems, which generally present a better performance, but are of limited use, a hybrid system has direct application on the bank industry, where the supervised acquisition of the reference specimen can be asked without difficulties and the verification is done without author's presence. Other new features include the concept behind the creation of an automatically generated static envelope, inspired by a handwritten reproduction model, as well as its personalization by prototypes, in order to reduce the within-class variation / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica
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