Vi har genomfört en studie med en kvantitativ ansats, i syfte att undersöka hur elevers läsförståelse kan påverka deras resultat i de nationella proven i matematik. Detta görs för att bidra med kunskap till lärare om var det är mest nödvändigt att lägga ner tid för elevers kunskapsutveckling i matematik. Metoden som används i denna studie innefattar en analys av dokument som innehåller data som samlats in från drygt 200 elevers resultat i de nationella proven i svenska och matematik för året 2021/2022. Den data som samlades in bearbetades genom regressionsanalyser. Det statistiskt signifikanta resultatet i studien visar på en stark korrelation mellan elevers läsförståelse och deras prestation i de nationella matematikproven. Slutsatsen framhäver att det kan finnas olika förklaringar till varför resultatet ser ut som det gör, en av orsakerna skulle kunna vara att de nationella proven i matematik innehåller för många textuppgifter som gör att elevernas läsförståelse kan spela en alltför betydande roll. / We have conducted a study with a quantitative approach, aiming to investigate how students' reading comprehension might influence their performance in the national mathematics exams. This is done to contribute knowledge to teachers about where it is most crucial to allocate resources for student success in mathematics. The method employed in this study involves an analysis of documents containing data gathered from over 200 students' results in the national exams in Swedish and mathematics for the year 2021/2022. The collected data was processed through regression analyses. The statistically significant result in the study reveals a strong correlation between students' reading comprehension and their performance in the national mathematics exams. The conclusion highlights that there are different explanations for why the result appears as it does, one of which is that there may be too many word problems in the national mathematics exams, and students' reading comprehension might play an overly significant role.

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I dagsläget hanteras papperstentamina manuellt på Karlstads universitet. Detta system är inte effektivt; det bildas köer vid ankomst \& inlämning och inlämningstidsstatistik är svår att ta vara på. Hade denna statistik funnits till lärares och administratörer hade de enklare kunnat bedöma tentaminas tidsåtgång. Lärare skulle kunna sätta en kortare skrivtid på många tentamina och fler tentamina schemaläggas av tentamensavdelningen. Trycket på skrivsalar är mycket stort idag och att schemalägga tentamina kan vara en stor utmaning. Målen med detta projektarbete var främst att skapa ett digitalt system som samlar och presenterar statistik kring inlämningstider för kursansvariga, och sekundärt att försöka effektivisera den generella studenthanteringen vid salstentamina. Planen var att skapa en mobilapplikation som skannar QR-koder på tentaminas försättsblad, och en webbsida som presenterar denna statistik. I denna uppsats diskuteras och utvärderas resultatet av en sådan lösning. Det system vi har utvecklat blev klart, men kunde inte driftsättas på Karlstads universitetet då vi inte fick åtkomst till existerande system som Ladok. Vi fick inte heller möjligheten att testa och därmed utvärdera systemet vid ett riktigt provtillfälle. / Pen-and-paper examinations are currently managed manually at Karlstad University. This system is not efficient; queues form during arrivals and submissions, and submission time statistics are difficult to make use of. If these statistics were to be made available to teachers and administrators, they would be able to more easily assess the time requirements for exams. Consequently, teachers would be able to allocate shorter writing times for many exams, and administrators thus schedule more of them. The pressure on exam halls is substantial today, and scheduling exams can be a challenge. The goal of this project was to create a digital system which gathers and presents statistics regarding submission times. The plan was to create a mobile application which scans QR codes found on exam cover sheets, and a website which presents these statistics. In this thesis, the results of such a solution are discussed and evaluated. The system we developed was completed, but was unable to be deployed in production at Karlstad University as we did not get access to any existing systems, such as Ladok. Futhermore, we were not given the opportunity to test and thus evaluate the system at an exam session.

Digitaliseringen av nationella prov i matematik är en pågående utveckling som väcker intresse och oro bland matematiklärare. Denna förändring innebär en övergång från traditionella pappersbaserade prov till digitala prov, vilket påverkar både lärare och elever. Forskning har visat på både fördelar och utmaningar med digitala prov, inklusive frågor om bedömning, tillgängligheten av teknisk utrustning och elevens teknikvana. Därför är det viktigt att förstå matematiklärares uppfattningar och erfarenheter av denna övergång för att effektivt stödja dem och deras elever i den nya digitala miljön. Denna studie syftade till att undersöka matematik lärares uppfattningar om hur digitaliseringen av nationella prov i gymnasieskolans matematik kommer att påverka genomförandet av dessa prov. Genom analys av intervjuer skapas sex tydliga teman relaterade till lärarnas uppfattningar. Genom att tillämpa fenomenografi som det teoretiska ramverket analyseras och tolkas lärarnas perspektiv och upplevelser. Resultaten av studien indikerar att matematiklärare har olika uppfattningar och förväntningar på digitaliseringen av nationellaprov i matematik. Dessa sex teman presenteras i studien: 1. Enklare att rätta: Lärarna ser digitaliseringen som ett sätt att minska rättningsbördan och möjliggöra mer rättvisa bedömningar genom central rättning. Dock finns oro över hur denna centrala rättning ska utföras. 2. Underlättande för elever med svårigheter: Digitaliseringen förväntas gynna elever som har svårt att skriva för hand eller elever med andra svårigheter genom tydligare redovisning och bättre översikt. 3. Teknikkrångel: Lärarna uttrycker oro över tekniska och logistiska problem som kan uppstå vid digitala prov, såsom tillgång till utrustning och nätverksproblem. 4. Mer fokus på tekniken? Det finns farhågor om att elevernas fokus kommer att hamna mer på tekniken än på matematiken, vilket kan påverka provresultaten. 5. Lättare att fuska? Läcker proven? Oro över ökade möjligheter till fusk och för att det ska vara större risk att proven ska läcka med införandet av digitala nationella prov. 6. Oroliga över en stor förändring: Lärarna uttrycker generell oro över den stora förändringen som digitaliseringen av nationella prov innebär, inklusive osäkerhet över hur de själva och eleverna kommer att anpassa sig till denna förändring. Dessa teman visar på både möjligheter och utmaningar med digitaliseringen av nationella prov i matematik, och det är tydligt att lärarna behöver stöd och förberedelse inför denna övergång. / The digitization of national math exams is an ongoing development that raises interest and concern among math teachers. This change involves a transition from traditional paper-based exams to digital ones, affecting both teachers and students. Research has shown both advantages and challenges of digital exams, including issues related to assessment, availability of technical equipment, and students' technological literacy. Therefore, it is important to understand math teachers' perceptions and experiences of this transition to effectively support them and their students in the new digital environment. This study aimed to investigate math teachers' perceptions of how the digitization of national math exams in high school will impact the administration of these exams. Through the analysis of interviews, six clear themes related to teachers' perceptions are identified. By applying phenomenography as the theoretical framework, teachers' perspectives and experiences are analyzed and interpreted. The results of the study indicate that math teachers have varied perceptions and expectations regarding the digitization of national math exams. These six themes are presented in the study: 1. Easier grading: Teachers see digitization as a way to reduce grading workload and enable fairer assessments through centralized grading. However, there are concerns about how this centralized grading will be conducted. 2. Aid for students with difficulties: Digitization is expected to benefit students who have difficulty writing by hand or students with other difficulties through clearer presentation and better overview. 3. Technical problems: Teachers express concerns about technical and logistical problems that may arise during digital exams, such as equipment access and network issues. 4. More focus on technology? There are fears that students' focus will shift more towards technology than mathematics, which may affect exam results. 5. Easier to cheat? Exam leaks? Concerns about increased opportunities for cheating and a greater risk of exam leaks with the introduction of digital national exams. 6. Worries about significant change: Teachers express general concerns about the major change that digitization of national exams entails, including uncertainty about how they and their students will adapt to this change. These themes highlight both opportunities and challenges of digitizing national math exams, and it is evident that teachers need support and preparation for this transition.

Atualmente os dados epidemiológicos sobre a exposição ao crack no Brasil são preocupantes, principalmente entre crianças e adolescentes na capital de São Paulo. É sabido que o crack apresenta um potencial maior que o correspondente a outras formas de uso da cocaína para causar dependência. Apesar de haver numerosos estudos e métodos validados para identificação e quantificação de cocaína em fluidos biológicos, o mesmo não ocorre para a caracterização de seu uso na forma de crack. Todos os métodos descritos para diferenciação de exposição ao crack empregam equipamentos de alto custo e que nem sempre são viáveis para a realidade econômica dos laboratórios públicos brasileiros. Este trabalho objetivou desenvolver e aplicar um método eficiente e viável economicamente para identificação e quantificação dos indicadores de uso do crack em amostras de urina provenientes do Núcleo de Toxicologia Forense do Instituto Médico-Legal de São Paulo. O método mostrou-se linear na faixa de interesse (intervalo dinâmico de 0,2 a 20 µg/mL) para éster metilanidroecgonina. Os limites de detecção e quantificação foram de 0,1 e 0,2 µg/mL respectivamente e os testes de estabilidade mostraram-se satisfatórios (degradação menor que 10% após 30 dias). Foram analisadas trinta e sete amostras de urina sendo que onze foram positivas para o indicador escolhido mostrando a utilidade do método no esclarecimento de ocorrências no âmbito forense, no sentido de indicar se a intoxicação da cocaína se deu por esta forma de exposição (utilização de crack). / At the present time, epidemiologic data on the prevalence of crack in Brazil is alarming, principally as it concerns young children and teenagers in the capital city of São Paulo of São Paulo State. It is known that with crack there is a greater potential for dependency than that corresponding to other forms of cocaine use in causing dependency. Although numerous studies and methods have been validated for the identification and quantification of cocaine in biological fluids, the same is not true for the characterization of its use in the form of crack. All the methods described for differentiating the exposure to crack employ very expensive equipment, which is not always viable to the economic reality of the Brazilian public laboratories. This study had as its objective the development and application of a method that is efficient and economically viable for the identification and quantification of products of crack biomarkers in urine samples from the Forensic Toxicology Lab of the Legal Medicine Institute of São Paulo. The method showed to be linear in the interest range (dynamic range from 0.2 to 20 µg/mL ) for anhydroecgonine methyl ester. The limits of detection and quantification were 0.1 and 0.2 µg/mL respectively, and the stability tests proved to be satisfactory (less than 10% lost after 30 days). Thirty seven urine samples were analyzed such that these 11 were positive for the chosen biomarker, showing the usefulness of the method for clarification purposes in the forensic environment, in the sense of indicating whether the intoxication from cocaine was of this form of exposition (crack use).

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-16T13:56:09Z No. of bitstreams: 1 Minéia Frezza.pdf: 1758793 bytes, checksum: 506bdf85c94ed952d8aa63d7ca579de0 (MD5) / Made available in DSpace on 2015-06-16T13:56:09Z (GMT). No. of bitstreams: 1 Minéia Frezza.pdf: 1758793 bytes, checksum: 506bdf85c94ed952d8aa63d7ca579de0 (MD5) Previous issue date: 2015-02-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação de mestrado consiste em um subprojeto de um estudo maior (Uma mulher, um feto, e uma má notícia: a entrega de diagnósticos de síndromes e de malformações fetais – em busca de uma melhor compreensão do que está por vir e do que pode ser feito, OSTERMANN, 2013) e tem como objetivo descrever a entrega de notícias por um geneticista a gestantes ou puérperas e seus/suas acompanhantes durante aconselhamentos genéticos gravados em áudio, em um hospital materno infantil do Sistema Único de Saúde (SUS), localizado na região sul do Brasil. Depois de transcrever os 54 aconselhamentos genéticos gravados, selecionamos apenas os 21 aconselhamentos que lidam com a comunicação de resultados de exames e os investigamos por meio da Análise da Conversa (SACKS; SCHEGLOFF; JEFFERSON, 1974) para descrever as ações envolvidas na fase das consultas em que ocorre uma sequência de entrega de boas e de más notícias. A análise de dados revelou que o geneticista em questão entrega as notícias seguindo uma sequência didática composta pelos seguintes elementos: (1) pré-anúncio da notícia, (2) retomada dos resultados de exames anteriores que indicavam a realização de exames mais especializados, (3) série(s) de apresentação de perspectiva (MAYNARD, 1992) nos casos de más notícias, (4) anúncio da notícia em si e, (5) apresentação de algo potencialmente “positivo” dentro de cada quadro, quando as notícias tratam de um diagnóstico “ruim”. Outra tendência evidenciada nos dados refere-se ao processo de alocação da categoria de porta-voz da notícia ao médico, à equipe de medicina fetal e à própria instituição quando a notícia é boa. Quando a notícia a ser entregue é ruim, há um processo de distanciamento da pessoa que a entrega, uma vez que essa categoria é alocada ao exame. Assim, por ser colocado na posição de agente dos verbos que montam a notícia, o exame acaba sendo apresentado como “o responsável” pelo porte e entrega das más notícias. Esse processo de “agentivização do exame” está ligado ao processo de “despessoalização da doença”, que acontece devido à falta de referentes pronominais e/ou nominais que categorizem o feto como portador da doença e dos sintomas apresentados durante a sequência de entrega de notícias. A análise linguístico-interacional da entrega de notícias neste contexto de pesquisa revela práticas recorrentes no evento aconselhamento genético. A partir dessas recorrências, o geneticista apresenta formas para lidar com o sofrimento de pacientes e de seus/suas acompanhantes que podem ser disseminadas na formação de profissionais de saúde em áreas em que a entrega de diagnósticos é prática do dia-a-dia. / This master’s dissertation consists of a subproject of a larger study (Uma mulher, um feto, e uma má notícia: a entrega de diagnósticos de síndromes e de malformações fetais – em busca de uma melhor compreensão do que está por vir e do que pode ser feito, OSTERMANN, 2013) and aims at describing the news delivery made by a geneticist to pregnant or puerperal women and their companion during audio recorded genetic counselings held in a mother and child hospital of the Sistema Único de Saúde (SUS), located in southern Brazil. After transcribing the 54 audiorecorded genetic counselings, we selected only the 21 counseling sessions which dealt with the communication of tests results. By taking a conversation analytical perspective (SACKS; SCHEGLOFF; JEFFERSON, 1974), the interactions were analyzed so as to describe the actions involved within the phase of the consultations in which the sequence of good and bad news delivery occurs. The data analysis reveals that the delivery of the news follows a didactic sequence composed by the following elements: (1) a news preannouncement, (2) a retake of the previous exams results which indicated the realization of more specialized exams, (3) a/some perspective-display series (MAYNARD, 1992) in case of bad news, (4) a news announcement itself, and when the news consists of a “bad” diagnosis, (5) a display of something potentially “positive” within each case. Another tendency revealed in the data refers to the process of placing the category of spokesperson to the doctor, to the staff of fetal medicine and to the institution itself when the news is good. When the news to be delivered is bad, on the other hand, there is a process of distancing of the person who delivers it and this category is alocated to the exam, which is then put in the position of the “agent” of the verbs that announce the news and, as a consequence, ends up being “the responsible one” for bearing it. This process of agentivization of the exam is linked to the process of “depersonalization of the disease”, which happens due to the lack of nominal and/or pronominal referents that categorize the fetus as the bearer of the disease and the symptoms presented throughout the news delivery sequence. The linguistic-interactional analysis of the news delivery in this research study shows recurring practices in the event genetic counseling. By these recurrences, the geneticist presents ways to deal with the patients and their companions’ distress, and these ways can be spread to the health professionals’ education in areas in which diagnosis delivery is a daily practice.

Made available in DSpace on 2016-04-27T17:13:04Z (GMT). No. of bitstreams: 1 Julio Cesar da Silva.pdf: 837518 bytes, checksum: debe86ad0bfcf3aa32d00c396f570f8f (MD5) Previous issue date: 2007-10-23 / Made available in DSpace on 2016-08-25T17:25:42Z (GMT). No. of bitstreams: 2 Julio Cesar da Silva.pdf.jpg: 4168 bytes, checksum: 39ec4287bfffaa2fe4a53a94a5947da6 (MD5) Julio Cesar da Silva.pdf: 837518 bytes, checksum: debe86ad0bfcf3aa32d00c396f570f8f (MD5) Previous issue date: 2007-10-23 / Secretaria da Educação do Estado de São Paulo / The goal of our research was to ascertain the relations between the brazilian educational instruments (textbook, official documents and the official exams), in that it refers to the contents of the Statistics, the light of the levels statistical literacy considered by the GAL (2002) and Wild and Pffannkuch (1999). In this paper, before the search for answers, we presented the definition of statistical thought as proposed by Gal (2002) and Wild and Pffannkuch (1999), and the level of statistical literacy shown by Shamos (1995), which our research was based on. We then analyzed the official documents (PCNEM, PNLEM, PCN+ and the Curricular Guidelines for High School) and found that their recommendations benefit the development of statistical thought. Finally, following the Praxeological Organization of Chevallard (1999), we analyzed two collections of textbooks and three official exams, in order to identify the tasks, the techniques and the theoretical-technological discourse favored by them. Based on that analysis, we can infer that the textbooks allow the development of skills that enable statistical literacy on the cultural level, whereas for a good performance in the official exams it is necessary to develop abilities that enable the statistical literacy on the functional level. In view of the results presented here, it is to be expected that our pupils show difficulties in solving the statistical questions of the official examinations; however, we believe that the shaping of statistical thought is essential for statistical learning, as well as a possible way to minimize those difficulties / Nossa pesquisa teve por objetivo verificar as relações entre os instrumentos educacionais brasileiros (livro didático, documentos oficiais e os exames oficiais), no que tange aos conteúdos da Estatística, a luz dos níveis de alfabetização estatística propostos por Gal (2002) e Wild e Pffannkuch (1999). Neste trabalho, antes da busca pelas respostas, apresentamos os termos do nosso quadro teórico. Em seguida, analisamos os documentos oficiais (PCNEM, PNLEM, PCN+ e Orientações Curriculares do Ensino Médio) e verificamos que suas recomendações favorecem o desenvolvimento do pensamento estatístico. Finalmente, analisamos, segundo a Organização Praxeológica de Chevallard (1999), duas coleções de livros didáticos e três exames oficiais de modo a identificar as tarefas, as técnicas e o discurso teórico-tecnológico por eles privilegiados. Com base nessa análise, podemos inferir que os livros didáticos permitem desenvolver habilidades propícias à alfabetização estatística no nível cultural, enquanto para um bom desempenho nos exames oficiais são necessárias habilidades propícias à alfabetização estatística no nível funcional. Tendo em vista os resultados apontados neste trabalho, é de se esperar que nossos alunos apresentem dificuldades nas resoluções das questões estatísticas dos exames oficiais, mas acreditamos que a formação do pensamento estatístico seja fundamental para a aprendizagem estatística, assim como um caminho possível para minimizar essas dificuldades

Submitted by Jailda Nascimento (jmnascimento@pucsp.br) on 2016-10-03T15:02:31Z No. of bitstreams: 1 Juliana Pereira Souto Barreto.pdf: 3340189 bytes, checksum: 30f53e6df08e1c7c68807c3dacf8ad70 (MD5) / Made available in DSpace on 2016-10-03T15:02:31Z (GMT). No. of bitstreams: 1 Juliana Pereira Souto Barreto.pdf: 3340189 bytes, checksum: 30f53e6df08e1c7c68807c3dacf8ad70 (MD5) Previous issue date: 2016-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The research reported here intends to analyze the production and the evaluation of the written text in the college entrance essays produced by undergraduate applicants. More specifically, this study verifies how the composition tests, written by the applicants during the admission process to the Rio Grande do Norte Federal University (UFRN), are related to the varying dimensions of Brazilian Portuguese, presented in Berber Sardinha, Kauffmann and Acunzo (2014). The research uses the theoretical framework of Corpus Linguistics and the methodological approach of Multidimensional Analysis. The study corpus is composed of one hundred essays written by applicants for admission to higher education undergraduate courses, tagged by Palavras parser and post-processed with a script, which calculates the score of each text into all of the six variation dimensions of Brazilian Portuguese. At first, it is checked how the applicants’ texts are related to the six Brazilian Portuguese varying dimensions. Then, it is observed the variation in relation to the grades award to these essays by examiners in order to determine whether and which correction criteria were met, based on the scores of the Brazilian Portuguese multidimensional analysis. Hence, the outcomes here are likely to provide important contributions to the field of textual production in Portuguese in Brazil, considering that it is vital to develop a more accurate understanding of the language in use applied to the teaching and learning of argumentative text production, written by applicants during their admission to undergraduate courses in Higher Education / A pesquisa aqui relatada tem por objetivo analisar a qualidade do texto escrito nas redações de vestibular produzidas por candidatos à graduação. Mais especificamente, esse estudo verifica o modo como as redações de candidatos ao Ensino Superior da Universidade Federal do Rio Grande do Norte (UFRN) elacionam-se às dimensões de variação do português brasileiro, apresentadas em Berber Sardinha, Kauffmann e Acunzo (2014a; 2014b; no prelo). Para isso, a pesquisa recorre ao arcabouço teórico da Linguística de Corpus e à abordagem metodológica da Análise Multidimensional (Biber, 1988). O corpus de estudo, composto por cem redações escritas por candidatos ao ingresso em cursos de graduação do Ensino Superior, foi analisado com o etiquetador Palavras e pós-processado com um script que calcula o escore de cada texto em cada uma das seis dimensões de variação do português brasileiro. Em um primeiro momento, é verificado o modo como as redações dos candidatos relacionam-se às seis dimensões de variação do português brasileiro. Em seguida, a variação é observada em relação às notas dadas às redações por examinadores, a fim de determinar se e quais os critérios de avalição, estipulados para a correção das redações de vestibular, foram atendidos, com base nos escores da análise multidimensional do português brasileiro. Por fim, acredita-se que os resultados aqui encontrados possam vir a proporcionar contribuições relevantes ao campo da produção textual em língua portuguesa no Brasil, uma vez que se faz necessário uma compreensão mais apurada da língua em uso aplicada ao ensino e ao aprendizado da produção de textos argumentativos por candidatos a ingresso em cursos de graduação do Ensino Superior

Cette thèse propose un nouveau processus de réservation d'examens IRM (Imagerie par Résonance Magnétique) afin de réduire les temps d’attente d’examens d'imagerie des patients atteint d'un AVC (Accident Vasculaire Cérébral) soignés dans une unité neurovasculaire. Le service d’imagerie réserve chaque semaine pour l'unité neurovasculaire un nombre donné de créneaux d'examens IRM appelés CTS afin d’assurer un diagnostic rapide aux patients. L'unité neurovasculaire garde la possibilité de réservations régulières appelées RTS pour pallier les variations des flux de patients.Nous donnons d'abord une formulation mathématique du problème d'optimisation pour déterminer le nombre et la répartition des créneaux CTS appelée contrat et une politique d'affectation des patients entre les créneaux CTS ou les réservations RTS. L'objectif est de trouver le meilleur compromis entre le délai d'examens et le nombre de créneaux CTS non utilisés. Pour un contrat donné, nous avons mis en évidence les propriétés et la forme des politiques d'affectation optimales à l'aide d'une approche de processus de décision markovien à coût moyen et coût actualisé. Le contrat est ensuite déterminé par une approche d'approximation Monté Carlo et amélioré par des recherches locales. Les expérimentations numériques montrent que la nouvelle méthode de réservation permet de réduire de manière importante les délais d'examens au prix des créneaux inutilisés.Afin de réduire le nombre de CTS inutilisé, nous explorons ensuite la possibilité d’annuler des créneaux CTS un ou deux jours en avance. Une approche de processus de décision markovien est de nouveau utilisée pour prouver les propriétés et la forme de la politique optimale d’annulation. Les expérimentations numériques montrent que l'annulation avancée des créneaux CTS permet de réduire de manière importante les créneaux CTS inutilisés avec une augmentation légère des délais d'attente. / This research is motivated by our collaborations with a large French university teaching hospital in order to reduce the Length of Stay (LoS) of stroke patients treated in the neurovascular department. Quick diagnosis is critical for stroke patients but relies on expensive and heavily used imaging facilities such as MRI (Magnetic Resonance Imaging) scanners. Therefore, it is very important for the neurovascular department to reduce the patient LoS by reducing their waiting time of imaging examinations. From the neurovascular department perspective, this thesis proposes a new MRI examinations reservation process in order to reduce patient waiting times without degrading the utilization of MRI. The service provider, i.e., the imaging department, reserves each week a certain number of appropriately distributed contracted time slots (CTS) for the neurovascular department to ensure quick MRI examination of stroke patients. In addition to CTS, it is still possible for stroke patients to get MRI time slots through regular reservation (RTS). This thesis first proposes a stochastic programming model to simultaneously determine the contract decision, i.e., the number of CTS and its distribution, and the patient assignment policy to assign patients to either CTS or RTS. To solve this problem, structure properties of the optimal patient assignment policy for a given contract are proved by an average cost Markov decision process (MDP) approach. The contract is determined by a Monte Carlo approximation approach and then improved by local search. Computational experiments show that the proposed algorithms can efficiently solve the model. The new reservation process greatly reduces the average waiting time of stroke patients. At the same time, some CTS cannot be used for the lack of patients.To reduce the unused CTS, we further explore the possibility of the advance cancellation of CTS. Structure properties of optimal control policies for one-day and two-day advance cancellation are established separately via an average-cost MDP approach with appropriate modeling and advanced convexity concepts used in control of queueing systems. Computational experiments show that appropriate advance cancellations of CTS greatly reduce the unused CTS with nearly the same waiting times.

Atualmente os dados epidemiológicos sobre a exposição ao crack no Brasil são preocupantes, principalmente entre crianças e adolescentes na capital de São Paulo. É sabido que o crack apresenta um potencial maior que o correspondente a outras formas de uso da cocaína para causar dependência. Apesar de haver numerosos estudos e métodos validados para identificação e quantificação de cocaína em fluidos biológicos, o mesmo não ocorre para a caracterização de seu uso na forma de crack. Todos os métodos descritos para diferenciação de exposição ao crack empregam equipamentos de alto custo e que nem sempre são viáveis para a realidade econômica dos laboratórios públicos brasileiros. Este trabalho objetivou desenvolver e aplicar um método eficiente e viável economicamente para identificação e quantificação dos indicadores de uso do crack em amostras de urina provenientes do Núcleo de Toxicologia Forense do Instituto Médico-Legal de São Paulo. O método mostrou-se linear na faixa de interesse (intervalo dinâmico de 0,2 a 20 µg/mL) para éster metilanidroecgonina. Os limites de detecção e quantificação foram de 0,1 e 0,2 µg/mL respectivamente e os testes de estabilidade mostraram-se satisfatórios (degradação menor que 10% após 30 dias). Foram analisadas trinta e sete amostras de urina sendo que onze foram positivas para o indicador escolhido mostrando a utilidade do método no esclarecimento de ocorrências no âmbito forense, no sentido de indicar se a intoxicação da cocaína se deu por esta forma de exposição (utilização de crack). / At the present time, epidemiologic data on the prevalence of crack in Brazil is alarming, principally as it concerns young children and teenagers in the capital city of São Paulo of São Paulo State. It is known that with crack there is a greater potential for dependency than that corresponding to other forms of cocaine use in causing dependency. Although numerous studies and methods have been validated for the identification and quantification of cocaine in biological fluids, the same is not true for the characterization of its use in the form of crack. All the methods described for differentiating the exposure to crack employ very expensive equipment, which is not always viable to the economic reality of the Brazilian public laboratories. This study had as its objective the development and application of a method that is efficient and economically viable for the identification and quantification of products of crack biomarkers in urine samples from the Forensic Toxicology Lab of the Legal Medicine Institute of São Paulo. The method showed to be linear in the interest range (dynamic range from 0.2 to 20 µg/mL ) for anhydroecgonine methyl ester. The limits of detection and quantification were 0.1 and 0.2 µg/mL respectively, and the stability tests proved to be satisfactory (less than 10% lost after 30 days). Thirty seven urine samples were analyzed such that these 11 were positive for the chosen biomarker, showing the usefulness of the method for clarification purposes in the forensic environment, in the sense of indicating whether the intoxication from cocaine was of this form of exposition (crack use).