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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Optimisation et aide à la décision pour la programmation des opérations électives et urgentes / Optimization and decision support for the scheduling of elective and non-elective surgeries

Bouguerra, Afef 07 July 2017 (has links)
Au sein d’un établissement hospitalier, le bloc opératoire représente un des secteurs les plus emblématiques et les plus coûteux. Le fonctionnement du bloc opératoire est orchestré par un programme opératoire qui consiste à construire un planning prévisionnel des interventions chirurgicales à réaliser pendant un horizon donné. La littérature abondante sur le sujet est unanime sur le fait que la construction du programme opératoire est une tâche complexe, car il s’agit non seulement de planifier et d’ordonnancer les interventions, mais aussi de satisfaire des exigences souvent antagonistes. Ce projet est le fruit d’une collaboration entre la Communauté d’Agglomération de Sarreguemines Confluences et la Région Lorraine, des membres du secteur hospitalier (Hôpital Robert Pax de Sarreguemines) et l’équipe Gestion Industrielle et Logistique (GIL) du Laboratoire de Génie Industriel, de Production et de Maintenance (LGIPM). L’objectif de cette recherche est d’apporter une aide aux gestionnaires du bloc opératoire, qui ont besoin de plus en plus des méthodes et des outils d’aide à la décision en vue d’optimiser leur fonctionnement. Pour répondre à ce besoin nous nous intéressons dans la première partie de cette thèse à la gestion des opérations électives en prenant en compte différentes contraintes et en particulier la disponibilité des chirurgiens. Nous nous plaçons dans le contexte d’une stratégie « open scheduling » et nous proposons deux modèles mathématiques permettant d’élaborer le programme opératoire. La complexité des modèles mathématiques et leur explosion combinatoire rendent difficile la recherche de l’optimum pour des tailles réalistes. Ceci nous a donc amené à proposer une heuristique constructive utilisant le modèle proposé et permettant d’obtenir des solutions là où la méthode exacte ne nous le permettait pas. Dans la seconde partie de cette thèse, nous considérons l’intégralité du processus opératoire (brancardage vers le bloc opératoire, préparation et anesthésie, acte chirurgicale et réveil). Nous modélisons ce processus comme un flow shop hybride à 4 étages avec contrainte de blocage de type RSb, et nous le résolvons à l’aide d’un algorithme génétique dont l’objectif est de synchroniser toutes les ressources nécessaires, en respectant au mieux le programme opératoire prévisionnel. Outre les opérations électives, nous nous intéressons dans la dernière partie aux opérations urgentes. Nous proposons un outil d’aide à la décision pour la gestion des opérations urgentes. En prenant en considération la pathologie et la gravité de l’état du patient, nous distinguons principalement 3 degrés d’urgences et proposons pour chacune un algorithme permettant d’intégrer en temps réel ces opérations dans le programme prévisionnel, tout en minimisant différents critères (temps d’attente avant affectation, heures supplémentaires, décalage par rapport aux anciennes dates de débuts) / The operating theater is one of the most critical and expensive hospital resources. Indeed, a high percentage of hospital admissions are due to surgical interventions. Rising expenditures spur health care organizations to organize their processes more efficiently and effectively. This thesis is supported by the urban community of Sarreguemines-France and the region of Lorraine-France, and is carried out in collaboration with the Centre Hospitalier de Sarreguemines - Hôpital Robert Pax. In the first part of this work, we propose two mathematical programming models to help operating theater managers in developing an optimal operating rooms scheduling. We also propose a constructive heuristic to obtain near optimal results for realistic sizes of the problem. In the second part of our work, the whole scheduling process is modeled as a hybrid four-stage flow shop problem with RSb blocking constraint, and is solved by a genetic algorithm. The objective is to synchronize all the needed resources around the optimal daily schedule obtained with the proposed mathematical model. The last part of our work is dedicated to non-elective surgeries. We propose a decision support tool, guiding the operating room manager, to handle this unpredictable flow of patients. Non-elective patients are classified according to their medical priority. The main contribution of the proposed decision support tool is to provide online assignment strategies to treat each non elective patient category. Proposed assignments are riskless on patient’s health. According to non-elective surgery classes, the proposed adjusted schedule minimizes different criteria such as patient’s waiting time, deviation from the firstly scheduled starting time of a surgery and the amount of resulting overtime
52

Proposition d'une méthode de conception systémique d'interface homme-système adaptée aux situations de multihandicap / Proposal of a systemic deging method of human-system interface integrating specificities of people with multiple disabilities

Roche, Amelie 16 December 2015 (has links)
Dans le domaine de la conception d’Interfaces Homme-Système (IHS), un des concepts clés est celui de la Conception Centrée Utilisateurs (CCU), qui place les utilisateurs au centre de la démarche. Bien que cette démarche constitue une avancée considérable pour proposer des solutions qui répondent aux besoins et aux attentes des utilisateurs finaux, elle n’est pas totalement adaptée lorsque ces derniers présentent des déficiences multiples. Egalement, malgré les bénéfices de la CCU, il est constaté que les concepteurs demeurent peu nombreux à appliquer cette démarche, l’utilisation d’approches plus classiques restant encore dominante. Les concepteurs sont peu sensibilisés à la prise en compte des utilisateurs finaux, encore moins lorsque ceux-ci présentent des déficiences.Face à ces constats, notre travail s’est articulé selon deux axes réalisés en parallèle. Nous avons élaboré et formalisé une méthode de conception systémique d’IHS : AMICAS (Approche Méthodologique Innovante de Conception Adaptée Systémique), afin de permettre la conception d’outils et services adaptés aux utilisateurs finaux, quelles que soient leurs spécificités. Cette méthode a été testée auprès d’enfants en situation de multihandicap dans un contexte scolaire et de personnes âgées en institution. En parallèle, nous avons élaboré un système d’aide à la décision, à destination des concepteurs d’IHS, afin de les sensibiliser à la prise en compte des utilisateurs finaux et de leurs déficiences dans les démarches de conception. Au regard des résultats obtenus, nous proposons en synthèse une version améliorée de la méthode de conception AMICAS et une mise en ligne de notre système d’aide. / In the field of Human-System Interface (HSI) design, one key concept is the User-Centred Design (UCD), an approach that considers the user as the centre of the design process. Although this approach is a significant advance to provide solutions that meets the needs and expectations of end-users, it is not totally suitable for end-users with multiple disabilities. Moreover, despite the benefits of the UCD, only few designers apply this approach. The use of standard approaches remains dominant. There is a general lack of awareness among designers on how take account of end-users, even less when the end-users have multiples disabilities.In view of these observations, our work has been structured to two main axes, conducted in parallel. We have elaborated and formalized design method of HSI, named AMICAS (Innovative Methodological Approach of Adapted Systemic Design), in order to design tools or services adapted for users, whatever their disabilities are. This method has been tested to children with multiple disabilities in educational context and with elderly in care homes. Also, we have developed a decision support tool. The purpose of this tool is to help designers to take into account end-users and their disabilities into the design stage. Based on the results, we suggest in synthesizing an improved version of AMICAS and we have published the decision support tool online.
53

Hydro-climatic Risk Assessment and Communication for Smallholder Farmers in Maharashtra / Bedömning och kommunikation av hydroklimatiska risker för småskaliga jordbrukare i Maharashtra

Ekström, Elin, Halonen, Jonna January 2021 (has links)
Smallholder farmers often have great entrepreneurial qualities that build on generations of experience. However, many farm management practices are poorly adapted to current climate change conditions. In order for farmers to understand the risks they are undertaking by following certain farming practices and to adapt accordingly, a decision support tool is being developed by researchers at TU Delft. The tool runs a socio-hydrological model, created in Python, in the back-end and provides farmer specific investment and profit data for different crops in the front-end. The aim of this study is to develop a risk assessment process that integrates hydro-climatic variability in the decision support tool, and to identify ways of communicating risk to smallholder farmers in Maharashtra, India. Two sources of variability were characterised based on a literature review of Indian farmers’ own risk perceptions; the untimely onset of the Indian Summer Monsoon and the frequency of dry spells. A sensitivity analysis was then carried out to investigate their respective effects on the farmers’ crop yields. The method proposed to evaluate these risks used a single variable, precipitation data, and a two-dimensional risk matrix to compound the two risk factors, over a time span of 14 years (2003-2016). However, the results indicate that it might be more beneficial to define dry spells in terms of crop water stress, instead of a precipitation threshold. This study also proposed a method for translating a cumulative distribution curve into a risk representation that is adapted for low-literacy users by combining numbers and text with graphics, color and voice descriptions. Ultimately, however, the usability of the tool cannot be determined solely through literature, but must involve the end-users in its design. / Småskaliga jordbrukare är goda entreprenörer som samlat på sig kunskaper och erfarenheter över flera generationer. Däremot är vissa metoder som jordbrukarna använder sig av idag för att förvalta sitt jordbruk inte anpassade till nutida klimatförändringar. För att jordbrukarna ska förstå riskerna som de åtar sig vid valet av dessa metoder försöker forskare vid TU Delft nu ta fram ett verktyg för att underlätta jordbrukares förmåga att ta självständiga men välgrundade beslut om sitt jordbruk. Verktyget är baserat på en socio-hydrologisk modell som är framtagen i Python och som förser specifika investerings- och inkomstdata för enskilda jordbrukare. Syftet med detta kandidatarbete är att bidra till verktyget genom att undersöka de hydroklimatiska risker som uppstår till följd av föränderliga och osäkra klimatologiska förhållanden för jordbrukare i delstaten Maharashtra, Indien. Två riskfaktorer karakteriserades baserat på en litteraturstudie om indiska jordbrukares riskuppfattningar: avvikelser i starten på den indiska sommarmonsunen och antal torrperioder under monsunsäsongen. Dessutom utfördes en känslighetsanalys för att undersöka om och hur den existerande modellens utdata av skörd påverkades av de valda riskfaktorerna. Monsunstarten och torrperioderna togs fram genom metoder som enbart använde historiska nederbördsdata över tidsperioden 2003-2016 och kombinerades sedan med hjälp av en tvådimensionell riskmatris. Resultaten visade att det fanns anledning att ifrågasätta hur torrperioderna definierades och att det kan vara mer fördelaktigt att undersöka vattenbrist för grödan, snarare än att enbart förlita sig på nederbördsdata. Vidare föreslog denna studie en metod för att översätta en kumulativ fördelningsfunktion till en grafisk riskframställning som är anpassad till användare med låg läskunnighet genom att kombinera siffror med text, grafik, färg och ljudförklaringar. I slutändan kan dock inte användbarheten av verktyget enbart avgöras utifrån litteratur, utan måste även inkludera återkoppling från slutanvändarna.
54

Climate change impacts on mountain snowpack presented in a knowledge to action framework

Sproles, Eric Allan 16 February 2012 (has links)
Throughout many of the world’s mountain ranges snowpack accumulates during the winter and into the spring, providing a natural reservoir for water. As this reservoir melts, it fills streams and recharges groundwater for over 1 billion people globally. Despite its importance to water resources, our understanding of the storage capacity of mountain snowpack is incomplete. This partial knowledge limits our abilities to assess the impact that projected climate conditions will have on mountain snowpack and water resources. While understanding the effect of projected climate on mountain snowpack is a global question, it can be best understood at the basin scale. It is at this level that decision makers and water resource managers base their decisions and require a clarified understanding of basin's mountain snowpack. The McKenzie River Basin located in the central-western Cascades of Oregon exhibits characteristics typical of many mountain river systems globally and in the Pacific Northwestern United States. Here snowmelt provides critical water supply for hydropower, agriculture, ecosystems, recreation, and municipalities. While there is a surplus of water in winter, the summer months see flows reach a minimum and the same groups have to compete for a limited supply. Throughout the Pacific Northwestern United States, current analyses and those of projected future climate change impacts show rising temperatures, diminished snowpacks, and declining summertime streamflow. The impacts of climate change on water resources presents new challenges and requires fresh approaches to understanding problems that are only beginning to be recognized. Climate change also presents challenges to decision makers who need new kinds of climate and water information, and will need the scientific research community to help provide improved means of knowledge transfer. This dissertation quantified the basin-wide distribution of snowpack across multiple decades in present and in projected climate conditions, describing a 56% decrease in mountain snowpack with regional projected temperature increases. These results were used to develop a probabilistic understanding of snowpack in projected climates. This section described a significant shift in statistical relations of snowpack. One that would be statistically likely to accumulate every 3 out of 4 years would accumulate in 1 out of 20 years. Finally this research identifies methods to improved knowledge transfer from the research community to water resource professionals. Implementation of these recommendations would enable a more effective means of dissemination to stakeholders and policy makers. While this research focused only on the McKenzie River Basin, it has regional applications. Processes affecting snowpack in the McKenzie River Basin are similar to those in many other maritime, forested Pacific Northwest watersheds. The framework of this research could also be applied to regions outside of the Pacific Northwestern United States to gain a similar level of understanding of climate impacts on mountain snowpack. / Graduation date: 2012
55

Potential for water reuse in Vietnam

Oertlé, Emmanuel, Vu, Duc Toan, Nguyen, Dinh Chuc, Näf, Laurin, Müller, Sandra Regina 14 May 2020 (has links)
Southeast Asian countries and Vietnam in particular are facing water security challenges; water reclamation is increasingly being considered as a favorable solution. Despite the availability of suitable technologies, several constraints often prevent stakeholders and especially decision makers exploiting their potential. In this paper we present the results of applying a decision support tool (DST) to evaluate water reclamation, support pre-feasibility studies and build capacity for water reclamation in Vietnam. The DST and its data are open access, providing information related to local and international water and wastewater quality standards. In this research we identified high potential Vietnamese case studies and conducted a systematic PISTLE analysis considering six dimensions (Political, Institutional, Social, Technical, Legal and Economic) at a multiple local stakeholder workshop. Key barriers and drivers for water reclamation implementation were identified. Measures proposed during the workshop could serve as a starting point for the development of water reclamation projects in Vietnam. / Các nước Đông Nam Á và đặc biệt là Việt Nam nói riêng hiện đang phải đối mặt với những thách thức về đảm bảo an ninh nguồn nước; cải tạo nguồn nước hiện đang được xem là một giải pháp thuận lợi. Mặc dù các công nghệ phù hợp đã có sẵn, nhưng một số hạn chế đã ngăn cản các bên liên quan và đặc biệt là những nhà làm chính sách có thể khai thác các tiềm năng của những công nghệ này. Trong bài báo này, chúng tôi trình bày các kết quả của việc áp dụng một công cụ hỗ trợ quyết định (DST) để đánh giá việc cải tạo nguồn nước, hỗ trợ các nghiên cứu tiền khả thi và xây dựng các khả năng cải tạo nguồn nước ở Việt Nam. DST và dữ liệu của nó là nguồn truy cập mở, cung cấp thông tin liên quan đến những tiêu chuẩn về chất lượng nước và nước thải của địa phương và quốc tế. Trong nghiên cứu này, chúng tôi đã xác định các tình huống điển hình có tiềm năng cao của Việt Nam và tiến hành phân tích PISTLE có hệ thống xem xét sáu khía cạnh (Chính trị, Thể chế, Xã hội, Kỹ thuật, Pháp lý và Kinh tế) tại một hội thảo của các bên liên quan tại địa phương. Những rào cản chính và yếu tố vận hành của việc thực hiện cải tạo nguồn nước cũng đã được xác định. Các giải pháp được đề xuất trong hội thảo này có thể đóng vai trò là điểm khởi đầu để phát triển các dự án cải tạo nguồn nước ở Việt Nam.

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