10 research outputs found
Análisis de problemas de control de Markov vía principio del máximo de Pontryagin y programación dinámica
Full text link"El control óptimo es una herramienta matemática utilizada para resolver problemas de optimización cuya evolución en el tiempo es susceptible a ser influenciado por fuerzas externas. La teoría del Control Óptimo inicia en los años 50.s, cuando en la incipiente era espacial se pretendía llevar una aeronave de la Tierra a un punto en el espacio en un tiempo mínimo y consumiendo la menor cantidad de combustible posible. Pontryagin y un equipo de matemáticos rusos desarrollaron la teoría de Control Óptimo Integrando el Principio de Optimalidad de Bellman, resultados fundamentales en la teoría Moderna de la Optimización [Ver 1]. Pontryagin, Bellman y Kalma fueron los primeros matemáticos en estudiar las ecuaciones diferenciales ordinarias como un modelo de sistemas de control. En el presente, la teoría de Control Óptimo abarca disciplinas tan diversas como Ingeniería mecánica, electrónica, economía, comunicaciones, navegación espacial, etc.
Análisis de problemas de control de Markov vía principio del máximo de Pontryagin y programación dinámica
No full text"El control óptimo es una herramienta matemática utilizada para resolver problemas de optimización cuya evolución en el tiempo es susceptible a ser influenciado por fuerzas externas. La teoría del Control Óptimo inicia en los años 50.s, cuando en la incipiente era espacial se pretendía llevar una aeronave de la Tierra a un punto en el espacio en un tiempo mínimo y consumiendo la menor cantidad de combustible posible. Pontryagin y un equipo de matemáticos rusos desarrollaron la teoría de Control Óptimo Integrando el Principio de Optimalidad de Bellman, resultados fundamentales en la teoría Moderna de la Optimización [Ver 1]. Pontryagin, Bellman y Kalma fueron los primeros matemáticos en estudiar las ecuaciones diferenciales ordinarias como un modelo de sistemas de control. En el presente, la teoría de Control Óptimo abarca disciplinas tan diversas como Ingeniería mecánica, electrónica, economía, comunicaciones, navegación espacial, etc.
Análisis de problemas de control de Markov vía principio del máximo de Pontryagin y programación dinámica
No full text"El control óptimo es una herramienta matemática utilizada para resolver problemas de optimización cuya evolución en el tiempo es susceptible a ser influenciado por fuerzas externas. La teoría del Control Óptimo inicia en los años 50.s, cuando en la incipiente era espacial se pretendía llevar una aeronave de la Tierra a un punto en el espacio en un tiempo mínimo y consumiendo la menor cantidad de combustible posible. Pontryagin y un equipo de matemáticos rusos desarrollaron la teoría de Control Óptimo Integrando el Principio de Optimalidad de Bellman, resultados fundamentales en la teoría Moderna de la Optimización [Ver 1]. Pontryagin, Bellman y Kalma fueron los primeros matemáticos en estudiar las ecuaciones diferenciales ordinarias como un modelo de sistemas de control. En el presente, la teoría de Control Óptimo abarca disciplinas tan diversas como Ingeniería mecánica, electrónica, economía, comunicaciones, navegación espacial, etc.
Aproximación vía Q-Learning en problemas de consumo-inversión
Full text link“El control óptimo estocástico es un área de las matemáticas dedicada a resolver problemas de optimización cuya evolución en el tiempo es susceptible a ser influenciado por variables aleatorias. Los procesos de control de Markov (PCM) son problemas de control estocástico, también conocidos como procesos de decisión de Markov, procesos de Markov controlados. Los PCM aparecen en muchos campos, por ejemplo, ingeniería, economía, investigación de operaciones, estadística, administración de recursos, control de epidemias, etc. La técnica básica para resolver problemas de control de Markov es la programación dinámica, técnica creada por Richard Bellman en 1953, con el propósito de optimizar problemas complejos que pueden ser sincretizados y secuencializados. Sin embargo, se complica su utilidad al trabajar con espacios de inter ́es de grandes dimensiones, en la literatura esto se conoce como maldición de la dimensionalidad. Machine learning es el estudio de algoritmos computacionales que automáticamente mejoran a través de la experiencia. Los algoritmos machine learning construyen un modelo matemático sobre datos muestrales, conocido como training data, para hacer predicciones o tomar decisiones sin ser explícitamente programado para ello”
A sociedade internacional contemporânea e o século XXI
Full text linkTese [doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Jurídicas. Programa de Pós-Graduação em Direito.Análise da origem, da afirmação e da conformação interna da sociedade internacional moderna e das principais perspectivas de realização da emergente sociedade internacional contemporânea, com destaque para a possibilidade de construção de uma ordem mundial justa e solidária
Das memórias às veredas: Revista USP - letras, cenas e sons
Full text linkTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-graduação em LiteraturaEsta tese tenta configurar o espaço ocupado pela literatura na Revista USP, partindo da reflexão que ali se realiza sobre a arte produzida nos anos 80 e 90. As criações recentes da música popular, do teatro e do cinema são submetidas a um balanço enquanto a literatura não recebe o mesmo tipo de abordagem crítica. Investigar as motivações e desdobramentos de tal postura por parte da revista é a principal proposição desta pesquisa, que busca desenvolver a seguinte hipótese: um vasto conjunto de ensaios publicados na Revista USP compõe um mosaico, no qual a reflexão acerca da literatura brasileira se configura através da constituição de um eixo monumental, formado por Memórias póstumas de Brás Cubas, de Machado de Assis e Grande sertão: veredas, de João Guimarães Rosa. Estas duas obras sustentam e demarcam os limites do cânone proposto pela revista, que posiciona a obra de Guimarães Rosa como última baliza do ciclo criativo da literatura brasileira. Entretanto, é possível perceber algumas sombras que conturbam o desenho nítido do referido eixo. A primeira delas é Grande sertão: veredas enquanto texto neobarroco e a segunda é uma antologia de poesia brasileira publicada na revista Universidad de México. This thesis tries to configure the space occupied by literature in Revista USP magazine, starting from the reflection about the art produced in the 80's and 90's. The popular music, the theater and the movies are submitted to an evaluation of their recent creations while the literature does not receive the same kind of critical approach. Investigating motivations and consequences of this attitude is the main proposition of this research, which intends to develop the following hypothesis: a great amount of texts published in Revista USP composes a mosaic, in which the reflection about Brazilian literature configures itself through the constitution of a monumental axle, formed by Memórias póstumas de Brás Cubas, written by Machado de Assis and Grande sertão: veredas, by João Guimarães Rosa. These books mark and support the limits of the canon proposed by the magazine, which considers Guimarães Rosa's narrative as the last sign of creativity in Brazilian literature. Although, it's possible to perceive some shadows that disturb the clearness of this axle. The first one is Grande sertão: veredas seen as a "neobarroco" text, and the second is an anthology of Brazilian poetry published at Universidad de México magazine
Dois lados da moeda?: Versus, um jornal alternativo, e Cultura, uma revista do MEC (1976 - 1978)
Full text linkDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em LiteraturaEsta dissertação é uma leitura comparativa de dois periódicos: Cultura, revista publicada pelo MEC (Ministério da Educação e Cultura) entre 1971 e 1984, e Versus, jornal alternativo que circulou entre 1975 e 1979. O recorte proposto se deteve nos anos de 1976, 1977 e 1978, ou, números 20 a 30 de Cultura e 01 a 23 de Versus. A partir do que os periódicos entendiam pelo termo "cultura", foram detectadas não só diferenças, mas, também, semelhanças entre ambos. Ainda com relação ao significado e função atribuídos à cultura por Cultura e Versus, detectamos as diferenças de posicionamento internas (isto é, dentro das publicações). Ao final, percebe-se que a "cultura", tanto por parte do Estado, como por parte dos opositores ao regime militar, é relegada a um segundo plano, seja pela conjuntura econômica, no primeiro caso, seja pela conjuntura política, no segundo
Pasquim, anos 70 & entrevista, um jogo de poder e sedução
Full text linkTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Letras/Literatura Brasileira
Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study
Full text linkBackground
Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies.
Methods
For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia.
Findings
Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8–13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05–6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50–75% of children and adolescents with familial hypercholesterolaemia not being identified.
Interpretation
Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life.
Funding
Pfizer, Amgen, Merck Sharp & Dohme, Sanofi–Aventis, Daiichi Sankyo, and Regeneron
Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study.
Full text linkBACKGROUND: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. METHODS: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. FINDINGS: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. INTERPRETATION: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. FUNDING: Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron
