The emergency medical services (EMS) provide the preliminary assistance and transportation for patients in need of urgent medical care in order to decrease the mortality rate and reduce the non-reversible effects of injuries. Since the objective is directly related to the human life, the value of the proposed solutions in order to improve the performance of EMS is highly welcomed. Mainly, there are three problems that EMS managers face with: location, allocation and redeployment of the EMS facilities/vehicles. Most of the studies in EMS literature focus on accurately modeling the probabilistic nature of the availability of an ambulance when it is called for. However, trivial changes in model parameters or estimates could dramatically change the optimal allocations generated by the probabilistic models and hence make the model invalid. In this study, we formulate the ambulance location problem as a deterministic multi-level maximal coverage model by which the total demand is tried to be covered as many as possible at multiple levels. Both a mathematical programming model and genetic algorithm-based heuristic approaches are proposed for the problem. The results indicate that the genetic algorithm-based solutions give reliable (near-optimal) and robust results in reasonable computational times for the problem. Moreover, the tradeoffs between the two performance measures, &lsquo / responsiveness&rsquo / and &lsquo / preparedness&rsquo / , are searched for / and our approaches with multi-level coverage are compared against the multiple coverage approaches in terms of these performance measures.

Στην εργασία αυτή αντιμετωπίζεται το πρόβλημα της χωροθέτησης εγκαταστάσεων και της κατανομής της ζήτησης σε περιφερειακό επίπεδο μέσω της παρουσίασης σχετικών μαθηματικών υποδειγμάτων μικτού ακέραιου προγραμματισμού, τα οποία στη συνέχεια εφαρμόζονται σε περιπτωσιολογική μελέτη. Η εργασία αφορά την χωροθέτηση δημοσίων εγκαταστάσεων. Ειδικότερα, αναφέρεται στην κατηγορία των προβλημάτων χωροθέτησης που χρησιμοποιούν την τυπική συνάρτηση αποδοτικότητας minsum. Σε αυτές τις περιπτώσεις οι εγκαταστάσεις τοποθετούνται έτσι ώστε να ελαχιστοποιούν το άθροισμα του συνολικού κόστους μεταφοράς. Η εργασία επικεντρώνεται στην χωροθέτηση οχληρών εγκαταστάσεων και συγκεκριμένα στη χωροθέτηση εγκαταστάσεων διαχείρισης αστικών απορριμμάτων. Αυτές οι εγκαταστάσεις ασκούν επιδράσεις όχι μόνο στον χώρο που καταλαμβάνουν, αλλά και σε μεγάλες εκτάσεις γύρω τους. Το πρόβλημα χωροθέτησης σε αυτές τις περιπτώσεις γίνεται ακόμα πιο πολύπλοκο λόγω της αναγκαίας συνεκτίμησης πολλαπλών κριτηρίων. Για τον σκοπό αυτό αναπτύσσεται ένα εξειδικευμένο πλαίσιο παραγωγής μαθηματικών υποδειγμάτων. Ειδικότερα,. στην παρούσα διδακτορική εργασία, δημιουργήθηκαν μαθηματικά υποδείγματα βελτιστοποίησης μικτού ακέραιου προγραμματισμού, τα οποία στη συνέχεια αναλύονται με μεθόδους πολυκριτηριακής ανάλυσης. Τα υποδείγματα αυτά εφαρμόζονται σε περιπτωσιολογική μελέτη με θέμα το χωροθετικό σχεδιασμό ενός περιφερειακού συστήματος διαχείρισης των αστικών απορριμμάτων για τον νομό Αχαΐας. / This study considers a facility location problem with demand allocation in regional level through mixed integer programming models that have been developed for these propose. Afterwards, these models applied in a case study. The present research concerns mostly the public facility location problems. In particular, the PhD dissertation deals with models using the typical mathematical function of efficiency minsum. Therese models locate the facilities in order to minimize the sum of costs for opening facilities and variable transportation costs. The problem becomes more complicated if, in addition it is necessary to locate undesirable facilities. The selection of proper sites for the facilities with obnoxious characteristics is a sensitive issue that has often cause social and political tension. The multiobjective nature of the problem implies that a number of environmental social and political criteria have to be considered. The study presents a model generating framework for formulating location allocation models that applied in municipal solid waste management systems. These models analyzed via multicriteria methodology in order to select the locations of different types of facilities at the regional level. Finally, we apply these concepts in a case study for the development of a solid waste management system for a specific region in Greece.

Biomass production is spatially distributed resulting in high transportation costs when moving dedicated biomass crops and crop residues. A multifaceted approach was taken to address this issue as the low bulk and energy density of biomass limits transportation efficiency. Two systems were analyzed for the conversion of biomass into a denser feedstock applicable to on-farm use. Pelletization was able to densify the material into a solid fuel. Using a pilot scale flat ring pellet mill, the density of the material was able to be increased to at least 4.4 times that of uncompressed material. Pellet durability was found to be strongly related to the moisture content of the material entering the mill. Unlike with ring roller pellet mills, a higher durability was typically seen forbiomass materials with a preconditioned moisture content of 20% (w.b.). From a liquid fuel standpoint, the conversion of lignocellulosic material into biobutanol on-farm was the second method investigated. For the pretreatment of biomass, alkaline hydrogen peroxide spray was demonstrated to be an effective enhancer of saccharification. The viability of on-farm biobutanol preprocessing bunker facilities within Kentucky was analyzed using Geographic Information systems (GIS) to specifically address transportation related factors. The spatial variability of corn field production, size, and location were resolved by utilizing ModelBuilder to combine the various forms of data and their attributes. Centralized and Distributed preprocessing with Centralized refining (DC) transportation systems were compared. Centralized was defined as transport of corn stover directly from the field to a refinery. Distributed-Centralized was specified as going from the field to the biobutanol bunker with corn stover and from the bunker to the refinery with a dewatered crude biobutanol solution. For the DC design, the location of the field and refinery were fixed with the biobutanol bunker location being variable and dependent upon differing maximum transportation (8-80 km) cutoffs for biomass transport from the field to biobutanol bunkers. The DC designs demonstrated a lower (38 - 59%) total transportation cost with a reduced fuel use and CO2 emissions compared to the centralized system.

Este estudo integrou sistemas de informação geográfica e métodos analíticos geoespaciais baseados em modelos de acessibilidade espacial e de locação-alocação com o objetivo de aprimorar o planejamento espacial de diferentes programas de saúde pública em áreas urbanas. Para estimar a acessibilidade espacial foi desenvolvido o modelo de três passos de área de influência flutuante (E3SFCA - Enhancement three-step floating catchment área) baseado em uma função Gaussiana, considerando um coeficiente de atrito e distâncias ao longo de uma rede de transporte, utilizando o algoritmo de Dijkstra. A metodologia foi aplicada e validada usando os programas de vacinação contra a raiva e de esterilização para cães e gatos da cidade de Bogotá, Colômbia. A escolha do método de cálculo da distância resolveu o problema de superestimação associado com a metodologia clássica que aplica zonas buffer em torno dos locais de serviço baseado em uma distância Euclideana. Em geral, não se encontrou uma adequada acessibilidade espacial aos dois programas. As zonas norte, central e periférica da cidade revelaram baixa ou nula acessibilidade aos serviços. Para determinar a alocação e realocação efetiva dos programas foram utilizados os problemas de máxima cobertura com demanda finita e de p-mediana ou de mínima impedância. A realocação proposta pelo modelo de máxima cobertura forneceu uma melhor distribuição dos serviços nas áreas mais povoadas com cães e gatos e garantiu uma acessibilidade espacial potencial a estes programas. O desenvolvimento deste trabalho pode trazer benefícios diretos para a sociedade em geral auxiliando no planejamento estratégico e melhorando a efetividade das ações públicas em áreas urbanas da América Latina. / This study integrated geographic information systems and geospatial analytical methods based on spatial accessibility and location-allocation models in order to improve the spatial planning of different public health programs in urban areas. To estimate the spatial accessibility, a Gaussian-based three-step oating catchment area (E3SFCA) method was developed, including a friction coeffcient and using distances along a street network based on Dijkstra\'s algorithm. The methodology was applied and valiated using the rabies vaccination and sterilization programs for dogs and cats in the city of Bogotá, Colombia. The choice of the distance calculation method solve the overestimation associated with the classic methodology that applies buffer zones around vaccination sites based on Euclidean (straight-line) distance. In general it was not observed an adequate spatial accessibility to both programs. The zones north, central and peripheral of the city revealed low or no access to services. To determine the effective allocation or reallocation of these programs the maximum coverage with finite demand and the p-median or minimum impedance problems were used. The relocation proposed by the maximum coverage model provided a better distribution of the services in the most populated areas and proportioned a potential spatial accessibility to these programs. The development of this work can provide direct benefits to society assisting in the strategic planning and improving the effectiveness of public policies in urban areas of Latin America.

Indiana University-Purdue University Indianapolis (IUPUI) / While optimization techniques have been studied since 300 B.C. when Euclid first considered the minimal distance between a point and a line, it wasn’t until 1966 that location optimization was first applied to a problem in healthcare. Location optimization techniques are capable of increasing efficiency and equity in the placement of many types of services, including those within the healthcare industry, thus enhancing quality of life. Medical imaging is a healthcare service which helps to determine medical diagnoses in acute and preventive care settings. It provides physicians with information guiding treatment and returning a patient back to optimal health. In this study, a retrospective analysis of the locations of current medical imaging centers in central Indiana is performed, and alternate placement as determined using optimization techniques is considered and compared. This study focuses on reducing the drive time experienced by the population within the study area to their nearest imaging facility. Location optimization models such as the P-Median model, the Maximum Covering model, and Clustering and Partitioning are often used in the field of operations research to solve location problems, but are lesser known within the discipline of Geographic Information Science. This study was intended to demonstrate the capabilities of these powerful algorithms and to increase understanding of how they may be applied to problems within healthcare. While the P-Median model is effective at reducing the overall drive time for a given network set, individuals within the network may experience lengthy drive times. The results further indicate that while the Maximum Covering model is more equitable than the P-Median model, it produces large sets of assigned individuals overwhelming the capacity of one imaging center. Finally, the Clustering and Partitioning method is effective at limiting the number of individuals assigned to a given imaging center, but it does not provide information regarding average drive time for those individuals. In the end, it is determined that a capacitated Maximal Covering model would be the preferred method for solving this particular location problem.

La question de l'accès au soin est cruciale dans notre société moderne. Un effet évident de la demande accrue de services de santé est l'augmentation du taux d'occupation dans les hôpitaux. La principale différence entre la dispensation de soins à l'hôpital et au domicile est la suivante: le patient doit se déplacer et toutes les ressources nécessaires à son traitement se trouvent dans le même endroit, tandis que dans les soins délivrés au domicile, les ressources doivent être déplacées au chevet du patient. Il existe plusieurs défis afin de pouvoir réaliser ce changement. Dans cette thèse nous traitons trois problèmes importants dans la conception des structures de soins à domicile. D’abord, la localisation des structures en minimisant les coûts logistiques, où nous développons trois modèles incluant différentes caractéristiques comme du système de santé comme les coûts liés aux déplacements des ressources, la variation de la demande dans le temps et l’existence et évolution des ressource libérales. Ces modèles nous permettent de proposer des localisations robustes dans le temps tout en assurant une couverture maximale et en minimisant les coûts. La deuxième problématique consiste au choix des activités et couverture épidémiologique et spatiale en tenant compte différentes activités et types de ressources, les autorisations pour réaliser les pathologies et la couverture. Deux modèles développés nous ont permis montrer les effets sur l’affectation de la demande et le dimensionnement de ressources induits par changements dans les coûts des libéraux, salaires et d’autorisation de servir la demande. Le troisième problème et celui du dimensionnement de ressources avec incertitudes de demande (volume, épidémiologique et géographique) et le modèle proposé tient compte du problème sous-jacent de déplacement des ressources à l’aide d’une estimation de la tournée réalisée. / The issue of access to heamthcare is crucial in our modern society. One obvious effect of the augmentation of healthcare services demand is the increasing occupancy rates in hospitals. The main difference between the provision of care at the hospital and at home is as follows: the patient is at hospital and all the resources necessary for its treatment are in the same place, while in the care delivered at home, resources must be moved to the bedside. There are several challenges in order to achieve this change. In this thesis we address three important issues in the design of structures of home care. First, the location of structures minimizing logistics costs, where we develop three models with different features such as traveling costs of resources, changes in demand over time and evolution of freelance resources. These models allow us to provide robust location over time while ensuring maximum coverage and minimizing costs. The second issue is the choice of activities, epidemiological and spatial coverage, taking into account different types of activities and resources, permissions to serve some pathologies and coverage. Two models developed allow us to show the effects on the demand allocation and resources planning induced by changes in the costs of freelance professionals and authorization to serve some pathologies. The third problem is the dimensioning of resources with demand uncertainty (volume, epidemiological and geographical) and the proposed model takes into account the underlying problem of moving resources using an estimate of the routes performed.

I och med urbaniseringen i det svenska samhället har många städer vuxit och utvecklats till storstäder. Storstäder har många utmaningar, allt ifrån att det ska finnas jobb och bostadsmöjligheter så måste även infrastrukturen i form av transportmöjligheter utvecklas i takt med befolkningsökningen. Större befolkning betyder mer människor i rörelse som lätt leder till försämrad framkomlighet i trafiken. Detta examensarbete har utförts åt Räddningstjänsten i Jönköpings kommun med syftet att bidra med ett underlag angående vad en ny brandstation skulle generera i minskade insatstider och samhällsnytta. Räddningstjänsten upplever att trafiken i Jönköpings tätort bidrar till sämre framkomlighet som i sin tur leder till att räddningstjänsten får längre insatstider än önskat. Därför planerar kommunen att en ny brandstation ska byggas. I examensarbetet har samhällsnyttan för den nya stationen undersökts genom att bygga en GIS-modell där det går att simulera och undersöka insatstiden för räddningstjänsten baserat på historiska händelser. En litteraturstudie utfördes för att ge en grundläggande kunskapsmässig förståelse för området examensarbetet behandlar. För att få förståelse och kunskap om nuläget för Räddningstjänsten i Jönköping utfördes tre olika intervjuer. Intervjuerna riktade sig till personer som är involverade i utvecklingsprocessen av Jönköpings infrastruktur. Den största delen av examensarbetet var skapandet av GIS-modellen och analysen av det resultat modellen genererade. Under hela examensarbetet har en dialog med Räddningstjänsten i Jönköping förts. Detta för att få hjälp med tolkning av den historiska data räddningstjänsten bidragit med men också för att kontrollera att GIS-modellen resulterade i svar som verkade sannolika och användbara. Examensarbetet resulterade i att en ny brandstation skulle minska medelinsatstiden för räddningstjänsten och generera samhällsnytta. Eftersom en modell aldrig kan ge samma resultat som verkligheten är det viktigt att ta andra saker än enbart GIS-modellens resultat i beaktning när det diskuteras vad samhällsnyttan och en minskning av medelinsatstiden egentligen har för betydelse. Examensarbetet anses kunna vara en del av det beslutsunderlag som används vid beslutsfattandet om en ny brandstation i Jönköpings kommun.

Shelters have been a significant part of the Swedish civil defense for a long time. In times of war in Europe, questions have been raised regarding the 64,000 shelters in Sweden and the civil population’s access to them. This study aims to investigate civilians’ access to the Swedish shelters, as well as where demand is high and low and where new shelters might be needed. The study has been conducted through Location-allocation analyses in GIS. Findings show that the accessibility to shelters varies throughout the country and that shelters are most accessible in urban areas. The average time taken to walk to the closest shelter in Stockholm Municipality is approximately 2 minutes. Findings also show that there are many new urban areas in Stockholm County where there are no shelters, and that there are densification areas where new shelters could be of use and meet demand as well.

No description available.

No description available.