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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.
11

[en] NETWORK SIMPLEX, ALGORITHM E IMPLEMENTATION / [pt] SIMPLEX PARA REDES, ALGORITMO E IMPLEMENTAÇÃO

JOAQUIM PEDRO DE V CORDEIRO 01 April 2009 (has links)
[pt] Este trabalho busca desenvolver o método Simplex para Redes na solução de problemas de Fluxo de Custo Mínimo. Este método consiste em uma adaptação do método Simplex primal em que são exploradas as características específicas da rede subjacente ao problema ao se buscar a solução ótima em um número finito de árvores geradoras. A árvore geradora ótima será obtida iterativamente através de sucessivas melhorias na estrutura de cada árvore formada. A maior eficiência do Simplex para Redes se dá tanto no menor número de iterações necessárias para se atingir o ótimo, quanto na maior velocidade destas iterações, trata-se, portanto, de um método bastante poderoso na resolução de problemas de Fluxo de Custo Mínimo. Serão, também, abordados aspectos práticos da implementação do algoritmo além da aplicação deste algoritmo implementado em VBA (Visual Basic for Applications) em um problema prático a título de exemplificação. / [en] The current work intends to develop a Network Simplex Method for solving Minimum Cost Flow problems. Such method consists of a primal Simplex Method adaptation in which specific characteristics of the network underlying the problem are investigated by searching for the optimal solution within a finite number of spanning trees. The optimal spanning tree is iteratively obtained through successive structure improvements in each formed tree. The higher efficiency of Network Simplex lies both in fewer iterations necessary to achieve the optimum and in the higher speed of these iterations. Therefore, it is a powerful method for solving Minimum Cost Flow Problems. Practical aspects of implementing the algorithm will be discussed, as well as the algorithm´s implementation in VBA (Visual Basic for Applications) through a practical instance.
12

Interference-Optimal Frequency Allocation in Femtocellular Networks

Ouda, Mahmoud 02 April 2012 (has links)
The evolution of Mobile Internet has led to the growth of bandwidth demanding applications like video streaming and social networking. The required data rates projected for such applications cannot be sustained by current cellular networks. New network architectures like Long Term Evolution (LTE) and LTE Advanced have been carefully engineered and introduced to fulfill such large data rates. The recent introduction of femtocells enabled high data rates and better coverage indoors, without the need for site establishment or upgrading the network infrastructure. Femtocells, however, will potentially suffer from major interference problems due to their expected dense and ad hoc deployment. The main contribution in this thesis is the introduction of a new and a very promising direction in deriving capable and efficient interference mitigation schemes, and comparing this direction to current techniques in the literature. Several works have studied the effect of interference on networks employing femtocells. In this thesis, we also survey such works and provide an overview of the elements considered in mitigating interference. We introduce a new scheme known for its optimality, and use it for frequency assignment in downlink femtocell networks. The algorithm is based on optimization search rather than greedy or heuristic methods. Experimental simulations will be shown to evaluate the proposed scheme against other schemes from the literature. / Thesis (Master, Computing) -- Queen's University, 2012-03-31 02:14:28.549
13

應急蜂巢式行動網路的拓撲設計 / Topology design for contingency cellular network

黃玉潔, Huang, Yu Chieh Unknown Date (has links)
大型災害頻傳傷亡慘重,若能把握於救災黃金72小時內救出受困民眾,則可望挽回更多寶貴的生命,但災區通訊網路基礎設施常因災害而遭受嚴重損毀,無法正常運作。救災工作在缺乏通訊系統的支援下,因溝通協調的困難而紊亂無章、效率低落。 本研究提出一個可快速恢復特定區域通訊服務的網路,並為其設計通訊的拓撲結構。我們稱該網路為應急蜂巢式行動通訊網路(Contingency Cellular Network),簡稱CCN網路。CCN網路利用無線電連接災區行動電話網路中斷訊但結構未損的基地台建構而成,具有建置速度快、使用門檻低等多項特點,可支援災區救援的緊急通訊。 本研究中,我們以各毀損基地台通訊範圍內的通訊需求人數與災區毀損程度,作為效益參數,嘗詴在蜂巢式網路的格網架構以及數量有限的緊急通訊設備下,選擇效益較高的位置點配置緊急通訊設備,建立應急蜂巢式行動網路的網路拓撲,此拓撲除追求最大救災效益外,並顧及通訊品質,避免建立負載失衡的連線。我們將問題塑模為一類似圖論中的K-Minimum Cost Spanning Tree (K-Cardinality Tree or KCT)問題,稱為Depth Bounded K-Maximum Profit Spanning Tree問題,並提供數個快速的啟發式演算法,可在緊急時快速地建立應急蜂巢式行動網路拓撲。 / When a catastrophic natural disaster occurs, the efficiency of disaster response operation is critical to life saving. However, communication systems, such as cellular networks, usually crashed due to various causes that make coordination difficult for many disorganized disaster response workers extremely. Unfortunately, rapid deployment of many existing emergency communication systems relies on a good transportation system, which is usually not available in a catastrophic natural disaster. We propose a Contingency Cellular Network (CCN) by connecting disconnected base stations together with wireless links and portable power generators. CCN can support existing mobile phone users with limited capability. Such a system can support a large number of voluntary workers in the early hours of a catastrophic natural disaster, thus saving many lives. Communication traffics, either voice or data, are forwarded hop-by-hop to the external network that remains operational. The efficiency and effeteness of CCN is obviously depends on the topology of such a forwarding network. This thesis addresses the design of forwarding topology aiming to maximize its efficiency. We take the degree of emergency degree of the damage, population of each stricken as the priority measure as well as the amount of emergency recovery resources as the constraint to determine the topology. We model the CCN topology design problem into a Depth Bounded K-Maximum Spanning Tree Problem. The problem is proven NP-hard and we designed an efficient heuristic algorithm (DBTB) to solve it. We also model CCN topology design problem into a Hop Concerned K-Maximum Spanning iii Tree Program and designed a HCTB algorithm to solve it. The simulation results show that DBTB algorithm can control tree depth effectively but HCTB can gain more profit.
14

Αναλυτικά μαθηματικά μοντέλα για προβλήματα παραγωγής και αποθήκευσης προϊόντων

Ζώη, Κωνσταντίνα 19 August 2010 (has links)
Ο προγραμματισμός παραγωγής και ελέγχου αποθεμάτων αποσκοπεί στην εύρεση της “χρυσής τομής” μεταξύ δυο αντιφατικών στόχων, από πλευράς ελαχιστοποίησης του συνολικού κόστους λειτουργίας μιας επιχείρησης: της μείωσης απ’ τη μια του διαθέσιμου αποθέματος και της ύπαρξης απ’ την άλλη ικανής ποσότητας διαθέσιμων αγαθών έτσι ώστε να καλύπτεται η ζήτησή τους στην αγορά. Ο συμβιβασμός μεταξύ αυτών των δυο στόχων επιτυγχάνεται με την δημιουργία κατάλληλων μαθηματικών κανόνων για τη χρονική (πότε;) και ποσοτική (πόσο;) διακίνηση του αποθέματος. Για την επίλυσή του έχουν προταθεί διάφορα μαθηματικά μοντέλα, τα οποία ποσοτικοποιούν τις παραμέτρους κόστους και εκφράζουν το συνολικό κόστος λειτουργίας της επιχείρησης με τη χρήση μιας συνάρτησης η οποία βελτιστοποιείται με εφαρμογή μαθηματικών μεθόδων. Η παρούσα εργασία επικεντρώνεται στην παρουσίαση των πιο ευρέως χρησιμοποιούμενων, προσδιοριστικών μοντέλων (όλες οι παράμετροι του συστήματος είναι γνωστές σταθερές) ενώ ο ορίζοντας σχεδιασμού θεωρείται πεπερασμένος. Στο πρώτο κεφάλαιο της παρούσας εργασίας παρουσιάζονται τα γενικά χαρακτηριστικά ενός προβλήματος παραγωγής και αποθήκευσης καθώς επίσης τα σχετικά με αυτό κόστη. Στο δεύτερο κεφάλαιο ακολουθεί η παρουσίαση των μοντέλων της Οικονομικής Ποσότητας Παραγγελίας, στα οποία θεωρείται ότι η ζήτηση πραγματοποιείται με ένα σταθερό ρυθμό και ότι το απόθεμα επιθεωρείται διαρκώς (ο χρόνος θεωρείται συνεχής). Αντίθετα, στα μοντέλα του τρίτου κεφαλαίου ο ορίζοντας σχεδιασμού χωρίζεται σε τακτά χρονικά διαστήματα, δηλαδή γίνεται η παραδοχή ότι ο χρόνος είναι διακριτός. Τέλος, στο τέταρτο αντιστοιχείται σε κάθε μοντέλο που αναλύθηκε στα προηγούμενα κεφαλαία, μια ολοκληρωμένη εφαρμογή η οποία επιλύεται λεπτομερώς. / Programmising the production and stock control aims to find the “golden mean” between two contradictory goals : as far as minimizing the total service expenses of a company is concerned, reduce the available cost, and on the other hand the existence of another one adequate quantity of available goods, so that their demand in the market can be covered. The compromising between these two goals can be achieved with the creation of appropriate mathematic rules about the time (when?) and amount (how much?) stock circulation. In order to achieve this compromising, many mathematical models have been proposed which quantify the subsiding costs and express the total service expenses of the company, using a function which is constantly being improved with the application of mathematical methods. The present project focuses on the presentation of the most widely used defining models, while the designing horizon is considered to be passed by. In the first part of the present project appear the general characteristics of a problem concerning the production and saving, as well as the relevant costs. The second part includes the presentation of the model about the Economic Order Quantity, in which it is regarded that demand is accomplished with a steady pace, and that the stock is constantly being checked (time is regarded to be continuous). On the other hand, in the model of the third part, the designing horizon is divided in regular time spaces, reaching the conclusion that time is apparent significant. Finally in the last part, each model analyzed in the previous chapters, is matched with a complete application, being solved in detail.
15

Otimização da potência de bombeamento aplicado ao planejamento do sistema hidrotérmico de potência via colônia de formigas

Alencar, Thiago Ribeiro de January 2017 (has links)
Orientadora: Profa. Dra. Patrícia Teixeira Leite Asano / Tese (doutorado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2017. / A área do setor elétrico que trata das necessidades energéticas por parte das usinas, de forma coordenada, é chamada de Planejamento da Operação de Sistemas Hidrotérmicos de Potência. Esta área tem como finalidade principal encontrar uma política operativa que forneça energia elétrica ao sistema, em um determinado período, com confiabilidade e por um custo mínimo. Sendo assim com a intenção de colaborar com está área, a Tese desenvolvida teve como objetivo principal aplicar a técnica de otimização de colônia de formigas para minimizar a potência de bombeamento através da definição do melhor caminho para construção de tubulações de transferência de água entre dois pontos. Para isso uma nova ferramenta computacional (programa IarAI) foi proposta e implementada considerando os dados georreferenciados de entrada, sendo o relevo da região e restrições ambientais. O programa IarAI foi implementado nas linguagens Java e JavaScript. Além disso, o IarAI é composto por quatro módulos que utilizam como técnicas de otimização as Colônias de Formigas e Algoritmos Genéticos. A metodologia e programa foram validados através de dois estudos de casos. O primeiro foi composto por três pontes que ligavam o ninho até a comida com um espaço de busca de 1200 m (40 pontos) x 480 m (16 pontos). O segundo caso teste foi aplicado no curso natural do rio Pinheiros na cidade de São Paulo com um espaço de busca de 34.710 m (1.157 pontos) x 17.960 m (568 pontos). Finalmente, os resultados apresentados demonstram a aplicabilidade da metodologia e algoritmo proposto. / The area of the electricity sector that addresses the energy needs of the plants, in a coordinated way, is called Operation of Hydrothermal Power Systems. This area has as main objective to find an operative policy that provides electrical energy to the system, in a certain period, with reliability and for a minimum cost. The main objective of this thesis was to apply the ant colony optimization technique to minimize pumping power by defining the best path for the construction of water transfer pipes between two points. A new computational tool (IarAI program) was proposed and implemented considering the georeferenced input data, being the relief of the region and environmental restrictions. The IarAI program was implemented in Java and JavaScript languages. In addition, the IarAI is composed of four modules that use as optimization techniques the Ant Colony and Genetic Algorithms. The methodology and program were validated through two case studies. The first one consisted of three bridges that connected the nest to the food with a search space of 1200 m (40 points) x 480 m (16 points). The second test case was applied in the natural course of the Pinheiros river in the city of São Paulo with a search space of 34,710 m (1,157 points) x 17,960 m (568 points). Finally, the presented results demonstrate the applicability of the methodology and proposed algorithm.
16

Towards New Bounds for the 2-Edge Connected Spanning Subgraph Problem

Legault, Philippe January 2017 (has links)
Given a complete graph K_n = (V,E) with non-negative edge costs c ∈ R^E, the problem multi-2EC_cost is that of finding a 2-edge connected spanning multi-subgraph of K_n with minimum cost. It is believed that there are no efficient ways to solve the problem exactly, as it is NP-hard. Methods such as approximation algorithms, which rely on lower bounds like the linear programming relaxation multi-2EC^LP of multi-2EC , thus become vital cost cost to obtain solutions guaranteed to be close to the optimal in a fast manner. In this thesis, we focus on the integrality gap αmulti-2EC of multi-2EC^LP , which is a measure of the quality of multi-2EC^LP as a lower bound. Although we currently only know cost that 6/5 ≤ αmulti-2EC_cost ≤ 3 , the integrality gap for multi-2EC_cost has been conjectured to be 6/5. We explore the idea of using the structure of solutions for αmulti-2EC_cost and the concept of convex combination to obtain improved bounds for αmulti-2EC_cost. We focus our efforts on a family J of half-integer solutions that appear to give the largest integrality gap for multi-2EC_cost. We successfully show that the conjecture αmulti-2EC_cost = 6/5 is true for any cost functions optimized by some x∗ ∈ J. We also study the related problem 2EC_size, which consists of finding the minimum size 2-edge connected spanning subgraph of a 2-edge connected graph. The problem is NP-hard even at its simplest, when restricted to cubic 3-edge connected graphs. We study that case in the hope of finding a more general method, and we show that every 3-edge connected cubic graph G = (V ′, E′), with n = |V ′| allows a 2EC_size solution for G of size at most 7n/6 This improves upon Boyd, Iwata and Takazawa’s guarantee of 6n/5 and extend Takazawa’s 7n/6 guarantee for bipartite cubic 3-edge connected graphs to all cubic 3-edge connected graphs.
17

Estudo da qualidade da matéria-prima de uma fábrica de ração para frangos de corte utilizando cartas de controle e técnicas Taguchi de custo mínimo - 2005 / Quality study of material for ration factory for cut chickens using control charts and techniques Taguchi of minimum cost ? 2005

Boas, érika Bastos Buttenmüller Vilas 24 February 2005 (has links)
Made available in DSpace on 2017-07-10T18:33:54Z (GMT). No. of bitstreams: 1 Dissertacao Erika Vilas Boas parte 1.pdf: 46912 bytes, checksum: 83dc25886d37cfeac84c60648054e192 (MD5) Previous issue date: 2005-02-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to verify the statistical quality control of the raw material used during the manufacturing of animal feed, which is being utilized for broiler chicken feed in businesses located in the western region of the state of Paraná. The raw material selected to be monitored were: corn and soy meal from vegetable origin, and meat flour, viscus and feather flour from animal origin. The variables that make up each group of raw material, such as humidity, raw protein, soluble protein, phosphorus, acidity, raw fiber, uretic activity and ethereal extract were collected during 2003 and 2004. The focus of this study of quality was on the application of individual X and AM control charts, and EWMA charts, Tabular CUSUM accumulated sum charts and V Mask CUSUM. An approach regarding the cost of quality loss was utilized in order to determine the economic interval of inspection related to the minimum cost, according to Taguchi s techniques. Regarding the corn raw material, the results show that the pondered control chart EWMA was the most efficient when analyzing the studied variables. As far as the capability of the process is concerned, we can conclude that only the humidity variable is below the desired specifications. The soy meal raw material had the individual X and AM charts as the most efficient and with an equivalent performance, and, regarding the process capacity, only the variable urease is up to the minimum value recommended by the CBAA. When it comes to the meat flour raw material, the tabular of the accumulated sums chart CUSUM was the least efficient and, as far as its process capacity is concerned, only the humidity variable is up to the minimum requirements required by the CBAA. Regarding the feather flour raw material, the individual AM chart was the most efficient, as far as the process capacity is concerned, none of the variables are up to the minimum specifications required by the CBAA. When it comes to the viscus flour raw material, the EWMA chars and the Tabular CUSUM were the most efficient, having an equivalent performance, and regarding the process capacity, only the humidity and acidity variables are up to minimum CBAA requirements. For the analysis of the minimum costs, we observed that the costs increase with the process tolerance increase (k) and decrease with the increase of the Cpl or Cpu values. Regarding the optimum interval analysis of inspection, the results show that the interval times decrease with the increase of the process tolerance (k), and increase with the increase of the values of Cpl or Cpu. / Este trabalho teve como objetivo verificar o controle estatístico de qualidade das matérias- primas na fabricação de ração que são utilizadas para a alimentação de frangos de corte, em empresa situada na região Oeste do Paraná. As matérias-primas selecionadas para serem monitoradas foram: milho e farelo de soja de origem vegetal e farinha de carne, farinha de vísceras e farinha de penas de origem animal. As variáveis que compõe cada matéria-prima como umidade, proteína bruta, proteína solúvel, fósforo, acidez, fibra bruta, atividade ureática e extrato etéreo foram coletadas nos anos de 2003 e 2004. O enfoque deste estudo da qualidade foi a aplicação dos gráficos de controle individual X e AM, gráfico ponderado EWMA, gráficos de somas acumuladas CUSUM Tabular e CUSUM Máscara V. Uma abordagem sobre custo de perda de qualidade foi utilizada para a determinação do intervalo econômico de inspeção em função do custo mínimo, segundo técnicas de Taguchi. Os resultados mostram com relação a matéria-prima milho que o gráfico de controle ponderado EWMA foi o mais eficiente na análise das variáveis estudadas. Quanto à capacidade do processo pode-se inferir que apenas a variável umidade está abaixo das especificações desejadas. A matéria-prima farelo de soja teve os gráficos Individual X e AM como os mais eficientes, tendo desempenho equivalente e, em relação à capacidade do processo, apenas a variável urease está atendendo o valor mínimo recomendado pelo CBAA. A respeito da matéria-prima farinha de carne, o gráfico de somas acumuladas CUSUM Tabular foi o mais eficiente e quanto a capacidade do processo apenas a variável umidade está atendendo as especificações mínimas exigidas pelo CBAA. Em relação à matéria-prima farinha de penas, o gráfico Individual AM foi o mais eficiente, e quanto a capacidade do processo, nenhuma variável está atendendo as especificações mínimas exigidas pelo CBAA. Em relação à matéria-prima farinha de vísceras, os gráficos EWMA e CUSUM Tabular foram os mais eficazes com desempenho equivalente, e quanto à capacidade do processo apenas as variáveis umidade e acidez estão atendendo as especificações mínimas exigidas pelo CBAA. Para análise dos custos mínimos, observou-se que os custos aumentam com o aumento da tolerância do processo (k) e diminuem com o aumento do valor de Cpl ou Cpu. A respeito da análise do intervalo ótimo de inspeção, os resultados mostram que os tempos de intervalo diminuem com o aumento da tolerância do processo (K), e aumenta com o aumento dos valores de Cpl ou Cpu.
18

A Structure based Methodology for Retrieving Similar Rasters and Images

Jayaraman, Sambhavi 22 June 2015 (has links)
No description available.
19

Optimal design of urban sewer systems

Saldarriaga, Juan 04 March 2024 (has links)
Tesis por compendio / [ES] Los sistemas de drenaje urbano, también conocidos como sistemas de alcantarillado, tienen el propósito de drenar tanto las aguas lluvias como las aguas residuales de nuestras ciudades. Estos sistemas son una de las diferentes infraestructuras civiles que permiten el correcto funcionamiento de las ciudades actuales. Los sistemas de alcantarillados pluviales se encargan de mover las aguas lluvias que caen en la ciudad en forma segura y en un tiempo razonable, sin permitir inundaciones, hacia los cuerpos receptores naturales localizados aguas abajo. Los sistemas de alcantarillado sanitario, por otra parte, tienen el objetivo de recolectar las aguas servidas, de origen domiciliario, industrial y comercial, y trasportarlas en forma segura hacia una planta de tratamiento de aguas residuales antes de enviarlas en forma definitiva hacia un cuerpo receptor o hacia un sistema de reuso, en caso de que este exista. Ambos tipos de alcantarillado, pero particularmente los sanitarios, tienen un profundo impacto sobre la salud pública con implicaciones sobre la viabilidad de una ciudad. La infraestructura de drenaje urbano existente plantea nuevos retos a la ingeniería hidráulica urbana. Por un lado, los sistemas de drenaje de aguas lluvias, además de verse sometidos a problemas de envejecimiento con deterioros de materiales y asentamientos de suelos, se están enfrentando a serios problemas causados por el Cambio Climático. En muchas ciudades este fenómeno está implicando cambios radicales en la hidrología urbana; en muchas ciudades las intensidades y frecuencias de los eventos de lluvia están aumentando con lo cual los sistemas existentes, que fueron diseñados para hidrologías diferentes, se quedan sin capacidad aumentando la frecuencia de las inundaciones urbanas con sus consecuencias sobre la seguridad y salud humana. Por otro lado, los sistemas sanitarios también presentan retos a la ingeniería por problemas de aumento de la densidad poblacional de las ciudades, la falta de resiliencia ante eventos externos como sismos, y a problemas de calidad de agua en los cuerpos receptores al interior de las zonas urbanas, en las aguas freáticas y las corrientes naturales de agua. Estos sistemas también se ven afectados por el deterioro de los materiales y los problemas de asentamiento de los suelos. Ahora, un problema diferente es la no existencia de sistemas de drenaje urbano en muchas ciudades de nuestro mundo, particularmente en aquellas localizadas en países en vías de desarrollo. En la gran mayoría de esos casos, esa falta de alcantarillados es causada por el alto costo de esa infraestructura cuya construcción hace inviable para los gobiernos locales. Además, el crecimiento de las zonas urbanas en esos países agrava el problema. No solamente la infraestructura necesaria se hace más grande y compleja, sino que aumentan los problemas de salud pública asociados con la falta de sanidad ambiental. Por consiguiente, el reto para la ingeniería hidráulica urbana moderna es lograr un mayor acceso a ese servicio esencial. Una de las formas de resolverlo es bajando los costos de construcción y operación de los sistemas de drenaje, haciéndolos financieramente viables a la vez que se mantienen su resiliencia y seguridad. De esta manera se ayudará a cumplir con el Objetivo de Desarrollo Sostenible No. 6 Agua Limpia y Saneamiento. Teniendo en cuenta lo anterior, el objetivo de esta tesis fue proponer una metodología que llevara al diseño de mínimo costo de redes de alcantarillado convencionales, manteniendo su resiliencia y facilidad de operación, a la vez que se cumplieran todas las restricciones hidráulicas, constructivas y de operación que, de acuerdo con la experiencia empírica internacional, son las apropiadas para garantizar un correcto comportamiento del sistema de drenaje. El diseño optimizado de una red de alcantarillado está compuesto por dos partes mutuamente dependientes: la selección del árbol y el diseño hidráulico. En esta tesis se resolvieron / [CA] Els sistemes de drenatge urbà, també coneguts com a sistemes de clavegueram, tenen el propòsit de drenar tant les aigües pluges com les aigües residuals de les nostres ciutats. Aquests sistemes són una de les diferents infraestructures civils que permeten el correcte funcionament de les ciutats actuals. Els sistemes de claveguerams pluvials s'encarreguen de moure les aigües pluges que cauen a la ciutat en forma segura i en un temps raonable, sense permetre inundacions, cap als cossos receptors naturals localitzats aigües avall. Els sistemes de clavegueram sanitari, d'altra banda, tenen l'objectiu de recol·lectar les aigües servides, d'origen domiciliari, industrial i comercial, i transportar-les en forma segura cap a una planta de tractament d'aigües residuals abans d'enviar-les en forma definitiva cap a un cos receptor o cap a un sistema de reuse, en cas que aquest existisca. Tots dos tipus de clavegueram, però particularment els sanitaris, tenen un profund impacte sobre la salut pública amb implicacions sobre la viabilitat d'una ciutat. La infraestructura de drenatge urbà existent planteja nous reptes a l'enginyeria hidràulica urbana. D'una banda, els sistemes de drenatge d'aigües pluges, a més de veure's sotmesos a problemes d'envelliment amb deterioracions de materials i assentaments de sòls, s'estan enfrontant a seriosos problemes causats pel Canvi Climàtic. En moltes ciutats aquest fenomen està implicant canvis radicals en la hidrologia urbana; en moltes ciutats les intensitats i freqüències dels esdeveniments de pluja estan augmentant amb la qual cosa els sistemes existents, que van ser dissenyats per a hidrologies diferents, es queden sense capacitat augmentant la freqüència de les inundacions urbanes amb les seues conseqüències sobre la seguretat i salut humana. D'altra banda, els sistemes sanitaris també presenten reptes a l'enginyeria per problemes d'augment de la densitat poblacional de les ciutats, la falta de resiliència davant esdeveniments externs com a sismes, i a problemes de qualitat d'aigua en els cossos receptors a l'interior de les zones urbanes, en les aigües freàtiques i els corrents naturals d'aigua. Aquests sistemes també es veuen afectats per la deterioració dels materials i els problemes d'assentament dels sòls. Ara, un problema diferent és la no existència de sistemes de drenatge urbà en moltes ciutats del nostre món, particularment en aquelles localitzades en països en vies de desenvolupament. En la gran majoria d'aqueixos casos, aqueixa falta de claveguerams és causada per l'alt cost d'aqueixa infraestructura la construcció de la qual fa inviable per als governs locals. A més, el creixement de les zones urbanes en aqueixos països agreuja el problema. No solament la infraestructura necessària es fa més gran i complexa, sinó que augmenten els problemes de salut pública associats amb la falta de sanitat ambiental. Per consegüent, el repte per a l'enginyeria hidràulica urbana moderna és aconseguir un major accés a aqueix servei essencial. Una de les maneres de resoldre-ho és baixant els costos de construcció i operació dels sistemes de drenatge, fent-los financerament viables alhora que es mantenen la seua resiliència i seguretat. D'aquesta manera s'ajudarà a complir amb l'Objectiu de Desenvolupament Sostenible No. 6 Aigua Neta i Sanejament. Tenint en compte l'anterior, l'objectiu d'aquesta tesi va ser proposar una metodologia que portara al disseny de mínim cost de xarxes de clavegueram convencionals, mantenint la seua resiliència i facilitat d'operació, alhora que es compliren totes les restriccions hidràuliques, constructives i d'operació que, d'acord amb l'experiència empírica internacional, són les apropiades per a garantir un correcte comportament del sistema de drenatge. El disseny optimitzat d'una xarxa de clavegueram està compost per dues parts mútuament dependents: la selecció de l'arbre i el disseny hidràulic. En aquesta tesi es van resoldre els dos problemes en forma separada des del punt / [EN] Urban drainage systems, also known as sewer systems, have the purpose of draining both rainwater and wastewater from our cities. These systems are one of the different civil infrastructures that allow the proper functioning of modern cities. Stormwater systems are responsible for moving the rainwater that falls in the city safely and in a reasonable time, without allowing flooding, to the natural receiving bodies located downstream. On the other hand, wastewater systems are designed to collect sewage from domestic, industrial, and commercial sources and transport it safely to a wastewater treatment plant before sending it definitively to a receiving body or to a reuse system, if available. Both types of sewer systems, but particularly wastewater systems, have an extensive impact on public health with implications for the viability of a city. The existing urban drainage infrastructure presents new challenges to urban hydraulic engineering. On the one hand, stormwater systems, in addition to being subjected to aging problems with deterioration of materials and soil settlement, are facing serious problems caused by climate change. In many cities this phenomenon is implying radical changes in urban hydrology; intensities and frequencies of rainfall events are increasing so that the existing systems, which were designed for different hydrological conditions, are running out of capacity, increasing the frequency of urban flooding with its consequences on safety and human health. On the other hand, wastewater systems also present engineering challenges due to problems of increasing population density in cities, lack of resilience to external events such as earthquakes, and water quality problems in receiving waters within urban areas, in groundwater, and natural water currents. These systems are also affected by the deterioration of materials and soil settlement problems. Now, a different problem is the non-existence of urban drainage systems in many cities of the world, particularly in those located in developing countries. In the vast majority of these cases, the lack of sewers is caused by the high cost of this infrastructure, making its construction unfeasible for local governments. In addition, the growth of urban areas in these countries exacerbates the problem. Not only does the necessary infrastructure become larger and more complex, but the public health problems associated with the lack of environmental sanitation increase. Therefore, the challenge for modern urban water engineering is to achieve greater access to this essential service. One way to solve this is by lowering the construction and operating costs of drainage systems, making them financially viable while maintaining their resilience and safety. This will help meet Sustainable Development Goal No. 6 Clean Water and Sanitation. Considering the above, the aim of this thesis was to propose a methodology that would lead to the minimum cost design of conventional sewer networks, maintaining their resilience and ease of operation, while complying with all the hydraulic, constructive, and operational restrictions that, according to international empirical experience, are appropriate to guarantee a correct behavior of the drainage system. The optimized design of a sewer network is composed of two mutually dependent parts: the layout selection and the hydraulic design. In this thesis, the two problems were solved separately from a mathematical point of view, maintaining their interdependence through an iterative process. For a given layout, which could be random for a first iteration, the hydraulic design problem was solved as a shortest path problem using the Bellman-Ford algorithm that guarantees the global minimum cost for that layout. The problem is model as a directed graph in which the nodes represent the combination of diameters and invert elevations at every manhole, and the arcs represent the diameter and upstream and downstream invert elevation of a specific pi / Saldarriaga, J. (2024). Optimal design of urban sewer systems [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202962 / Compendio
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INTERFACE DE ANÁLISE DA INTERCONEXÃO EM UMA LAN USANDO CORBA / Software development (graphical user interface) that makes possible to analyze the interconnection in a LAN (Local Area Network) using CORBA (Common Object Request Broker Architecture)

MONTEIRO, Milson Silva 07 June 2002 (has links)
Made available in DSpace on 2016-08-17T14:52:43Z (GMT). No. of bitstreams: 1 Milson Monteiro.pdf: 1924077 bytes, checksum: 78f931b493f756dec0edee7a465e1099 (MD5) Previous issue date: 2002-06-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This works concern software development (graphical user interface) that makes possible to analyze the interconnection in a LAN (Local Area Network) using CORBA (Common Object Request Broker Architecture) on distributed and heterogeneous environment among several outlying machines. This works presents paradigms of graphs theory: shortest paths problems (Dijkstra-Ford-Moore-Belman), maximum flow problems (Edmonds-Karp) and minimum cost flow problems (Busacker-Gowen) to formalize the interface development. We discoursed on the graphs theory and networks flows that are essentials to guarantee theoretical insight. / O objeto de estudo deste trabalho é o desenvolvimento de um software (interface gráfica do usuário) que possibilita analisar a interconexão de uma LAN (Local Area Network) usando CORBA (Common Object Request Broker Architecture) em ambientes distribuídos e heterogêneos entre diversas máquinas periféricas. Este trabalho apresenta os paradigmas da teoria de grafos: menor caminho (Dijkstra, Ford-Moore-Belman), fluxo máximo (Edmonds-Karp) e fluxo de custo mínimo (Busacker-Gowen) para formalizar o desenvolvimento da interface. Discorremos sobre a teoria de grafos e fluxos em redes que são relevantes para garantir o embasamento teórico.

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