<p>We investigate a certain epidemics model, with and without noise. Some parameter analysis is performed together with computer simulations. The model was presented in Iacus (2008).</p>

Delivering health care services in an efficient and effective way has become a great challenge for many countries due to the aging population worldwide, rising health expenses, and increasingly complex healthcare delivery systems. It is widely recognized that models and analytical tools can aid decision-making at various levels of the healthcare delivery process, especially when decisions have to be made under uncertainty. This thesis employs stochastic models to improve decision-making under uncertainty in two specific healthcare settings: inpatient flow management and infectious disease modeling. In Part I of this thesis, we study patient flow from the emergency department (ED) to hospital inpatient wards. This line of research aims to develop insights into effective inpatient flow management to reduce the waiting time for admission to inpatient wards from the ED. Delayed admission to inpatient wards, also known as ED boarding, has been identified as a key contributor to ED overcrowding and is a big challenge for many hospitals. Part I consists of three main chapters. In Chapter 2 we present an extensive empirical study of the inpatient department at our collaborating hospital. Motivated by this empirical study, in Chapter 3 we develop a high fidelity stochastic processing network model to capture inpatient flow with a focus on the transfer process from the ED to the wards. In Chapter 4 we devise a new analytical framework, two-time-scale analysis, to predict time-dependent performance measures for some simplified versions of our proposed model. We explore both exact Markov chain analysis and diffusion approximations. Part I of the thesis makes contributions in three dimensions. First, we identify several novel features that need to be built into our proposed stochastic network model. With these features, our model is able to capture inpatient flow dynamics at hourly resolution and reproduce the empirical time-dependent performance measures, whereas traditional time-varying queueing models fail to do so. These features include unconventional non-i.i.d. (independently and identically distributed) service times, an overflow mechanism, and allocation delays. Second, our two-time-scale framework overcomes a number of challenges faced by existing analytical methods in analyzing models with these novel features. These challenges include time-varying arrivals and extremely long service times. Third, analyzing the developed stochastic network model generates a set of useful managerial insights, which allow hospital managers to (i) identify strategies to reduce the waiting time and (ii) evaluate the trade-off between the benefit of reducing ED congestion and the cost from implementing certain policies. In particular, we identify early discharge policies that can eliminate the excessively long waiting times for patients requesting beds in the morning. In Part II of the thesis, we model the spread of influenza pandemics with a focus on identifying factors that may lead to multiple waves of outbreak. This line of research aims to provide insights and guidelines to public health officials in pandemic preparedness and response. In Chapter 6 we evaluate the impact of seasonality and viral mutation on the course of an influenza pandemic. In Chapter 7 we evaluate the impact of changes in social mixing patterns, particularly mass gatherings and holiday traveling, on the disease spread. In Chapters 6 and 7 we develop agent-based simulation models to capture disease spread across both time and space, where each agent represents an individual with certain socio-demographic characteristics and mixing patterns. The important contribution of our models is that the viral transmission characteristics and social contact patterns, which determine the scale and velocity of the disease spread, are no longer static. Simulating the developed models, we study the effect of the starting season of a pandemic, timing and degree of viral mutation, and duration and scale of mass gatherings and holiday traveling on the disease spread. We identify possible scenarios under which multiple outbreaks can occur during an influenza pandemic. Our study can help public health officials and other decision-makers predict the entire course of an influenza pandemic based on emerging viral characteristics at the initial stage, determine what data to collect, foresee potential multiple waves of attack, and better prepare response plans and intervention strategies, such as postponing or cancelling public gathering events.

Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Keskinocak, Pinar; Committee Member: Ergun, Ozlem; Committee Member: Goldsman, David; Committee Member: Hupert, Nathaniel; Committee Member: Swann, Julie. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Cette thèse analyse les transformations de l'espace urbain qui ont eu lieu depuis la moitié du XIXe siècle dans la ville de Fortaleza - capitale de l'état du Ceará - à partir du discours médical-hygiéniste. La transformation urbaine qui s'est produite s'insère dans un contexte international d'hégémonie du discours médical qui prêchait l'hygiène et l'assainissement des villes. Ces idées ont eu un rôle fondamental dans le processus de formation et d'ordonnancement de l'espace urbain. Pour comprendre et expliquer la constellation d'idées et de pratiques il a fallu étudier le rôle du médecin dans l'élaboration d'une nouvelle forme de penser la ville à partir de l'hygiène et de la santé, l'application et l'adaptation des modèles d'hygiène et d'urbanisation européens - principalement français -, inventoriant les actions réactives et préventives de l'Etat pendant les sécheresses et les épidémies ; les politiques de prévention contre les maladies et les campagnes contre les épidémies. La Géographie a contribué à comprendre le rôle des idées et à l'impact des changements de mentalité pour la génération de nouvelles configurations territoriales et des paysages géographiques. La diffusion de théories médicales entre la population et les gouvernants a eu un effet significatif dans l'ordonnancement des villes brésiliennes. / From the hygienic and medical point of view, this thesis analyses the transformation of the urban space that took place in the city of Fortaleza - Capital of Ceará State (Brazil) - since mid XIX Century. The occurred urban transformation is comprised in an international context of the hegemony of the medical discourse that preached city's hygiene and sanitation. These ideas played a fundamental role in the process of formation and organisation of the urban space; in order to understand and explain the constellation of ideas and practices, it was necessary to study the role of the doctor in the design of a new way of thinking the city from the hygiene and health perspective, in addition to its application and adaptation to the European hygienic and urbanisation patterns - notably the French ones -, listing the State reactive and preventive actions during droughts and epidemics; the preventive policies against illness and campaign against epidemics. Geography contributed to the understanding of the role of ideas and of the impact of changes in the mentality for the creation of new territorial layouts and geographical landscapes. The dissemination of medical theories amongst the population and public authorities had significant impact in the organisation of Brazilian cities.

Desde sua eclosão na década de 1980 na forma de epidemia, a AIDS tem sido principalmente associada a homossexuais masculinos: inicialmente partindo da literatura médica, essa visão espalhou-se também para o público leigo e mantém-se viva no imaginário popular, ainda que, a partir da década de 1990, tenha havido um movimento para reconhecer a parcela cada vez mais vitimada pela síndrome: mulheres heterossexuais. A essa progressão, deu-se o nome de feminização do HIV/AIDS, uma narrativa sobre uma suposta mudança no perfil da epidemia. No entanto, é possível encontrar informações sobre ocorrências da doença em mulheres desde muito antes, e é por meio de uma análise discursiva acerca do tema que este trabalho nasce: embora a epidemia da AIDS nunca tenha deixado de ter mulheres como parte expressiva de seus portadores, os discursos e narrativas desde 1980 vêm sistematicamente falhando em incluí-las e direcionar políticas de prevenção e combate que levem em consideração as particularidades das vivências femininas ou a complexidade de sua vulnerabilidades – parte de um sistema intricado de influência bidirecional entre cultura e materialidade. Utilizando metodologias, conceitos e textos de diversas áreas de produção de conhecimento, me proponho a analisar a inserção do corpo feminino na narrativa da epidemia HIV/AIDS privilegiando a historicidade e as diferentes versões desse objeto. / Since its occurrence in the 1980s in epidemic form, AIDS has been mainly associated to homosexual males: initially put forth by medical literature, this view spread to the non-expert audience as well and is kept alive in people’s imaginations, even though by the 1990s there has been a movement towards recognizing the group increasingly victimized by the syndrome: heterosexual women. This progression has been dubbed feminization of HIV/AIDS, a narrative about a supposed change in the profile of the epidemic. However, it is possible to find information about occurrence of the disease in women since much earlier, and it is through a discoursive analysis around the subject that this work came to be: even though the AIDS epidemic has never been without women as an expressive part of its carriers, mainstream discourse and narratives have since the 1980s systematically failed to include them and direct prevention and treatment politics that take into account particularities of femalehood or the complexity of its vulnerabilities – part of an intricate system of bidirectional influence between culture and materiality. By using methodologies, concepts, and texts from several fields of generation of knowledge, I propose to analyze the insertion of the female body in the HIV/AIDS epidemic focusing on the historicity and the different versions of this object.

Desde sua eclosão na década de 1980 na forma de epidemia, a AIDS tem sido principalmente associada a homossexuais masculinos: inicialmente partindo da literatura médica, essa visão espalhou-se também para o público leigo e mantém-se viva no imaginário popular, ainda que, a partir da década de 1990, tenha havido um movimento para reconhecer a parcela cada vez mais vitimada pela síndrome: mulheres heterossexuais. A essa progressão, deu-se o nome de feminização do HIV/AIDS, uma narrativa sobre uma suposta mudança no perfil da epidemia. No entanto, é possível encontrar informações sobre ocorrências da doença em mulheres desde muito antes, e é por meio de uma análise discursiva acerca do tema que este trabalho nasce: embora a epidemia da AIDS nunca tenha deixado de ter mulheres como parte expressiva de seus portadores, os discursos e narrativas desde 1980 vêm sistematicamente falhando em incluí-las e direcionar políticas de prevenção e combate que levem em consideração as particularidades das vivências femininas ou a complexidade de sua vulnerabilidades – parte de um sistema intricado de influência bidirecional entre cultura e materialidade. Utilizando metodologias, conceitos e textos de diversas áreas de produção de conhecimento, me proponho a analisar a inserção do corpo feminino na narrativa da epidemia HIV/AIDS privilegiando a historicidade e as diferentes versões desse objeto. / Since its occurrence in the 1980s in epidemic form, AIDS has been mainly associated to homosexual males: initially put forth by medical literature, this view spread to the non-expert audience as well and is kept alive in people’s imaginations, even though by the 1990s there has been a movement towards recognizing the group increasingly victimized by the syndrome: heterosexual women. This progression has been dubbed feminization of HIV/AIDS, a narrative about a supposed change in the profile of the epidemic. However, it is possible to find information about occurrence of the disease in women since much earlier, and it is through a discoursive analysis around the subject that this work came to be: even though the AIDS epidemic has never been without women as an expressive part of its carriers, mainstream discourse and narratives have since the 1980s systematically failed to include them and direct prevention and treatment politics that take into account particularities of femalehood or the complexity of its vulnerabilities – part of an intricate system of bidirectional influence between culture and materiality. By using methodologies, concepts, and texts from several fields of generation of knowledge, I propose to analyze the insertion of the female body in the HIV/AIDS epidemic focusing on the historicity and the different versions of this object.

A presente pesquisa investiga as epidemias de febre amarela - em 1897 e 1900 - e de gripe espanhola - em 1918 - ocorridas em Sorocaba e a atuação do médico Álvaro César da Cunha Soares no seu combate, a fim de revelar as condições sanitárias de uma cidade que passava por grandes transformações, como o crescimento urbano e a industrialização, em um contexto de consolidação da medicina oficial e de acirrados debates em torno das questões relacionadas à saúde pública. Para tanto, traça-se um panorama das condições sanitárias e de saúde pública de Sorocaba entre o final do século XIX e o início do século XX, apontando o agravamento dos problemas sociais e o aumento do número de casos de determinadas enfermidades. Desse modo, pretende-se demonstrar como a condição de vida da população pobre sorocabana foi se deteriorando cada vez mais enquanto a cidade apresentava um relativo crescimento urbano e industrial. As epidemias de febre amarela são reconstituídas, abordando-se questões políticas, sociais e científicas que se desenrolaram no decorrer dos surtos epidêmicos, em um contexto de disputa entre o poder estadual, representado pelo Serviço Sanitário do Estado de São Paulo, e os poderes locais, representados por médicos e autoridades públicas municipais, na condução das medidas de combate às epidemias. A epidemia de gripe espanhola na cidade representou um desafio às autoridades públicas locais e uma ameaça à estabilidade econômica local - em um momento em que o crescimento industrial da cidade era colocado em evidência. Desse modo, estudando as epidemias que assolaram Sorocaba na virada do século XIX para o XX e acompanhando a atuação de Álvaro Soares nesse contexto, pretende-se compreender melhor a relação entre a consolidação da medicina oficial no Estado de São Paulo e suas implicações nas práticas em saúde pública / This research investigates epidemics of yellow fever - in 1897 and 1900 - and the Spanish flu - in 1918 - occurred in Sorocaba and the performance of the medical Álvaro César Soares da Cunha in combating them, in order to reveal the sanitary conditions of a city passing through major transformations, such as urban growth and industrialization, in a context of consolidation of official medicine and heated debates on issues related to public health. To this end, draws up an overview of public health and sanitary conditions of Sorocaba in the late nineteenth and the early twentieth century, pointing to the worsening of social problems and the increasing number of cases of certain diseases. Thus, it is intended to demonstrate how the living conditions of the poor in Sorocaba was deteriorating more and more as the city had a relative urban and industrial growth. The yellow fever epidemics are reconstituted, addressing political, social and scientific issues that unfolded over the outbreaks, in a dispute context between state power, represented by the State Sanitation Service of São Paulo, and local authorities, represented by physicians and municipal authorities, in the conduct of measures to combat epidemics. The Spanish flu epidemic in the city was a challenge to local public authorities and a threat to local economic stability - at a time when the industrial growth of the city was placed in evidence. Thus, studying the epidemics that ravaged Sorocaba in the late nineteenth century to the twentieth and monitoring the performance of Alvaro Soares in this context, it is intended to better understand the relationship between the consolidation of official medicine in the State of São Paulo and its implications for practice in public health

Para além de um fenômeno biológico, as enfermidades são fenômenos históricos, pois a forma que a sociedade a prova é demonstrada por meio como pensam e agem em preveni-las, transmiti-las, estudá-las, compreendê-las e curá-las, e que estão calcadas pelas práticas e discursos da medicina, pelas políticas públicas desenvolvidas pelo Estado em saúde e pelos aspectos socioculturais e econômicos presentes em diferentes comunidades. A historiografia elaborou diversos estudos sobre a epidemia de AIDS (Síndrome da ImunoDeficiência Adquirida) que procuravam compreendê-la perante sua repercussão na sociedade, as comparações com outras experiências epidêmicas vividas pelas diferentes coletividades, as particularidades geográficas de infecção, a mortalidade pela enfermidade, as respostas, os preconceitos e as metáforas construídas em torno da doença por diferentes grupos sociais. Este texto apresenta o projeto de mestrado sobre como se deu a epidemia na cidade de Itapetininga (1985-1999). O presente estudo de dimensão histórica busca compreender, pelos fios dos documentos, como foram incorporados discursos e práticas sobre a AIDS no universo de uma cidade do interior paulista. Por meio da leitura da produção jornalística local e do levantamento dos projetos e requerimentos propostos na Câmara Municipal de Itapetininga, farar-se-á uma reconstrução das representações históricas sobre a doença / Beyond a biologic phenomenon, illnesses are historical fact, because of the society rehearses experience is demonstrated by show it thinks and acts to prevent, to transmit, to study, to understand, to represent and to heal. All those elements are guided by the practices and discourses of medicine, of public health policy developed by Estate and by sociocultural and economical aspects presents in many different communities. The historiography elaborated several studies about AIDS epidemic aiming at understanding it before it repercussion in society, as comparison with other epidemics by many different collectivities, the geographic infection particularities, the mortality by the illness, the answers, the preconceptions and metaphors built around of the disease by many different social groups. This work presents a master\'s degree project about how was the AIDS epidemic in Itapetininga city during the early period (1989-1996). By means of documents, the present study of historical dimension search to understand, how speeches and practices about AIDS were incorporated in the universe of a city from São Paulo State countryside. Through the reading of the local journalistic production and the survey of the projects and requirements proposed in the Municipality of Itapetininga, a reconstruction of the historical representations about the disease will be made

Orientador: Cristina de Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T20:46:44Z (GMT). No. of bitstreams: 1 HernandezTasco_Aleidys_M.pdf: 2499047 bytes, checksum: 236f6901a7068d237ee969ad03880acc (MD5) Previous issue date: 2013 / Resumo: Em 1927 a luta contra a febre amarela parecia finalizada no continente americano. A Fundação Rockefeller, instituição filantrópica estadunidense que tinha como principal objetivo o combate da febre amarela na primeira metade do século XX, assegurava que a doença estava quase erradicada. No entanto, a ocorrência das epidemias de febre amarela no Rio de Janeiro em 1928 (Brasil) e em Socorro em 1929 (Colômbia), colocou em dúvida as medidas profiláticas recomendadas e aplicadas tanto pelos órgãos nacionais de Saúde Pública como os da Fundação Rockefeller que participou da luta contra essa doença em ambos os países. Ao mesmo tempo em que ocorriam as epidemias, uma controvérsia instalou-se em torno à descoberta de Stokes, Bauer e Hudson na África, em 1927, que demonstrou que a febre amarela era facilmente inoculável no Macacus Rhesus. Tal descoberta acabou por rejeitar a concepção etiológica estabelecida em 1919 por Noguchi. A nova descoberta dos pesquisadores, as epidemias e a rejeição da teoria de Noguchi geraram uma enorme desconfiança na época, dando a sensação de que nada era seguro em assuntos relacionados à febre amarela, despertando uma crise nos estudos da doença. Esta pesquisa assume a responsabilidade de fazer um estudo comparativo a partir da ciência, da política e da técnica que ambos os países usaram no combate à doença, com intuito de conhecer as experiências desenvolvidas com o fenômeno da febre amarela. Assim, a dissertação tem dois objetivos principais. Primeiro, analisar o processo histórico da febre amarela, a fim de entender a crise que predominou nos estudos da doença entre os anos de 1927 e 1930. Para isso iremos analisar os múltiplos atores locais, nacionais e internacionais no domínio teórico e técnico da doença, durante a epidemia de febre amarela no Rio de Janeiro, em 1928-29, e em Socorro, em 1929. O segundo objetivo é analisar as manifestações científicas contra o avanço da febre amarela no Brasil e na Colômbia, a partir das duas últimas grandes epidemias registradas no Rio de Janeiro (1928-1929) e em Socorro (1929), através das tensões entre o ideal de uma ciência médica universal, representada pela Fundação Rockefeller e pelas Conferências Pan-Americanas, e as práticas de saúde pública, representadas por médicos e pesquisadores, elaboradas localmente para minimizar o alcance da febre amarela no período de 1930 a 1948 / Abstract: In 1927 the fight against yellow fever seemed to have concluded in American continent. In the first half of the twentieth century, a philanthropic American organization had as primary goal the fight against that outbreak (The Rockefeller Foundation) and, they ensured that epidemic was almost completely eradicated in that time. Nonetheless, two yellow fever outbreaks recorded in Rio de Janeiro in 1928 (Brazil) and Socorro in 1929 (Colombia) put in doubt the prophylactic measures recommended and implemented by the National Agencies of Public Health and the Rockefeller Foundation. This later institution took part in the fight against the disease in both countries. A controversy was established, while those epidemics took place in both countries, due to the discovery made by Stokes, Bauer e Hudson in Africa in 1927, which demonstrated Macacus Rhesus could be easily inoculated with the virus of yellow fever. That discovery eventually rejected the etiological agent theory established by Noguchi in 1919. In this fashion, with the new discovery, the epidemics and the rejecting of Noguchi's theory, a huge distrust grew up in those days, giving the impression that nothing was safe in issues related to yellow fever, and generating a crisis in studies of disease. Therefore, a comparative study from science, policy and technical that both Colombia and Brazil used in fighting against disease is carried out in this research in order to know the experiences developed with the yellow fever. In this manner, this dissertation has two mains objectives. First, the historical process of yellow fever will be analyzed by this research to understand the crisis that prevailed in studies of that disease between 1927 and 1930. For this reason, the multiple local actors, national and international in theoretical and technical field of the disease were analyzed during yellow fever outbreak in 1928-29 in Rio de Janeiro and in 1929 in Socorro. Second, several scientific manifestations against the progress of yellow fever in Brazil and Colombia were also studied from the last two major epidemics recorded in Rio de Janeiro (1928-1929) and Socorro (1929). Thus, controversies between an ideal of universal medical science represented by Rockefeller Foundation and Pan-American Conference, and the local public health practices developed to minimize the propagation of yellow fever in the period between 1930 and 1948 / Mestrado / Politica Cientifica e Tecnologica / Mestra em Política Científica e Tecnológica

Cette thèse s'inscrit dans le cadre du projet ANR HOST (Hôpital : Optimisation, Simulation et évitement des Tensions) qui vise à étudier et résoudre le problème de tension aux urgences hospitalières. Le projet cherche premièrement à définir rigoureusement la notion de tension et puis d'utiliser des outils mathématiques pour proposer des solutions qui prennent en compte la complexité du système de santé. Malgré la récurrence des phénomènes de tension, ils sont limités dans le temps et sollicitent par conséquent des solutions à court terme. La difficulté de trouver des solutions efficaces est principalement due à l'incertitude et au dynamisme caractéristique du service des urgences. D'une année à une autre, l'intensité de l'épidémie, et donc le nombre de patients se présentant aux urgences peut varier drastiquement. De plus, pour un même nombre de patients, il est difficile d'estimer correctement la charge de travail qu'il représente. L'objectif de cette thèse est donc de proposer des solutions stratégiques, tactiques et opérationnelles de gestion des ressources en prenant en compte les aléas caractéristiques des urgences. D'un point de vue stratégique nous étudions la distribution optimale de la capacité de travail sur une période épidémique. Ensuite, nous traitons le problème de confection des postes de travail journalier en fonction de la dynamique de la demande. Nous étudions également la possibilité d'affecter des postes d'astreinte aux médecins pendant les périodes épidémiques. Finalement, nous traitons le problème d'affectation des heures supplémentaires aux ressources dans un contexte plus opérationnel. / In France, the problem of overcrowding in Emergency Departments (ED) is particularly relevant today because of increasing admissions and budget restrictions in health establishments. Formally, overcrowding can be defined as a situation where the demand surpasses the service capacity. Studies that have dealt with ED overcrowding have mostly dealt with issues of patient flow management and resource management.Our work focuses on resource management and more particularly on the impact that human resources have on ED overcrowding. In the first part of the study, we formulate the capacity allocation problem in a generic form. As such, we examine the capacity management problem and derive interesting properties for a general demand distribution and a normal demand distribution. Then, we examine the cyclic shift scheduling problem as it exists in ED. This research allows us to examine different cyclic scheduling strategies and answer the question of whether lack of flexibility in the schedules has an impact on the waiting time of patients. We propose an original stochastic linear formulation for the problem that accounts for the non-stationary work demand. After that we evaluate two scheduling mechanisms to reduce overcrowding in EDs: on-call duties and overtime hours. We study the conditions under which these mechanisms can be beneficial. The on-call duties problem is modeled as a two-stage stochastic optimization problem and the overtime management problem as a Markov decision problem.