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141	Caracterização de redes complexas: aplicação à modelagem relacional entre sistemas autônomos da Internet / Complex networks characterization: application to relational modeling between internet autonomous systems Nilton Alves Junior 29 March 2007 (has links) Neste trabalho, foram utilizadas técnicas e conceitos tipicamente encontrados em estudos de Redes Complexas, uma sub-área da Física Estatística, para caracterizar a Internet e sua evolução em uma década, de 1998 a 2007. Foi considerada como unidade básica de análise, a estrutura Sistema Autônomo. Nesta caracterização, foram utilizadas várias ferramentas computacionais desenvolvidas em linguagem C/C++, que permitiram classificar, simular e modelar propriedades dinâmicas. Dentre estas propriedades podemos destacar o coeficiente de conectividade, fundamental para os estudos topológicos, e o parâmetro menor caminho médio, ambos baseados nas propriedades da matriz adjacência. Os dados experimentais foram inicialmente obtidos nos roteadores de borda da RedeRio de Computadores - FAPERJ e posteriormente, os dados relativos ao intervalo de estudo, foram retirados da base de dados disponibilizada pela Universidade de Oregon. Foi proposto um modelo de crescimento de uma rede complexa baseado nas premissas de crescimento contínuo e conexão preferencial não linear com suporte aos mecanismos de rearranjo e novas conexões entre nós já existentes. Este modelo se mostrou bastante adequado no estudo das propriedades consideradas. Foi desenvolvido um método para cálculo do menor caminho médio que apresentou performance superior àqueles normalmente utilizados pela comunidade acadêmica. O comportamento da topologia sob o ponto de vista da distribuição de probabilidades de conexão e do ranque de conectividade, apresentaram comportamento linear constante no período estudado com coeficientes médios iguais a -2,0 e -0,93, respectivamente. O parâmetro menor caminho médio global da Internet permaneceu praticamente inalterado e igual a 4, 2 ao longo da década estudada. / Connection networks are observed in many areas of human knowledge. The characterization and topological studies of these networks may be performed through distribution of connectivity degrees, rank properties, shortest path length between nodes, adjacency matrix etc, typical concepts from Complex networks, a filed of study of Statistical Physics domain. In this thesis we characterize the Internet connections evolution from 1998 to 2007. The Internet may be seen under several levels of reach and complexity considering different basic units. A wide vision is to consider the Internet basic element as an Autonomous System - AS, which is defined as a cluster of LANs or routers submitted to the same policy of usage, connectivity and technically administrated by the same network management group. The complex network considered in this work is composed by Autonomous Systems (vertices) and the established tra connection (edges) between them obtained from the BGP routing table. Many interesting property of this networks is analyzed, e.g. degree distribution (the rank and outdegree exponents) from 1998 to 2007 and the shortest path length (L), obtained by a proposed computational method (Friburgo algorithm) among each pair of ASs represented in the adjacency matrix. Finally, we present the behavior of the power law function and the shortest path length of the Internet for each year. Simulations of the connections network were carried out by a proposed model developed from continuous growth premises, possibilities of new and rearranging connections. This model was based on the concept of potential preferable connection showing a stable exponential factor that reproduces the true shortest path parameter over the decade. Menor caminho médio Modelagem relacional Leis de potência Redes complexas Redes livres de escala Sistemas autônomos Física estatística Teoria dos grafos Redes (Matemática) Autonomous system Complex networks Statistical physics Graph theory Nets (Mathematics) Power Law Scale-free networks Relational modeling, Shortest path MATEMATICA APLICADA
142	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. Teoria de Grafos Fluxos em Redes Problema do Menor Caminho Problema do Fluxo Máximo Problema do Fluxo de Custo Mínimo Algoritmos Paralelos Graph Theory Networks Flows Shortest Path Problem Maximum Flow Problem Minimum Cost Flow Problem Parallel Algorithms
143	Optimal Route Planning for Electric Vehicles / Optimal Route Planning for Electric Vehicles Juřík, Tomáš January 2013 (has links) In this work we present algorithms that are capable of calculating paths to destination for electric vehicles. These paths can be based on the simple metrics such as the distance, time or the paths can be based on more advanced metric such as the minimum energy demanding metric. This metric is parameterizable by the physical construction of the electrical vehicle. We also propose a new algorithm that computes energy optimal paths that are more acceptable by the driver, because it also takes into consideration the time metric while computing the path.
144	An Analysis of Consequences of Land Evaluation and Path Optimization Murekatete, Rachel Mundeli January 2018 (has links) Planners who are involved in locational decision making often use raster-based geographic information systems (GIS) to quantify the value of land in terms of suitability or cost for a certain use. From a computational point of view, this process can be seen as a transformation of one or more sets of values associated with a grid of cells into another set of such values through a function reflecting one or more criteria. While it is generally anticipated that different transformations lead to different ‘best’ locations, little has been known on how such differences arise (or do not arise). Examples of such spatial decision problems can be easily found in the literature and many of them concern the selection of a set of cells (to which the land use under consideration is allocated) from a raster surface of suitability or cost depending on context. To facilitate GIS’s algorithmic approach, it is often assumed that the quality of the set of cells can be evaluated as a whole by the sum of their cell values. The validity of this assumption must be questioned, however, if those values are measured on a scale that does not permit arithmetic operations. Ordinal scale of measurement in Stevens’s typology is one such example. A question naturally arises: is there a more mathematically sound and consistent approach to evaluating the quality of a path when the quality of each cell of the given grid is measured on an ordinal scale? The thesis attempts to answer the questions highlighted above in the context of path planning through a series of computational experiments using a number of random landscape grids with a variety of spatial and non-spatial structures. In the first set of experiments, we generated least-cost paths on a number of cost grids transformed from the landscape grids using a variety of transformation parameters and analyzed the locations and (weighted) lengths of those paths. Results show that the same pair of terminal cells may well be connected by different least-cost paths on different cost grids though derived from the same landscape grid and that the variation among those paths is affected by how given values are distributed in the landscape grid as well as by how derived values are distributed in the cost grids. Most significantly, the variation tends to be smaller when the landscape grid contains more distinct patches of cells potentially attracting or distracting cost-saving passage or when the cost grid contains a smaller number of low-cost cells. The second set of experiments aims to compare two optimization models, minisum and minimax (or maximin) path models, which aggregate the values of the cells associated with a path using the sum function and the maximum (or minimum) function, respectively. Results suggest that the minisum path model is effective if the path search can be translated into the conventional least-cost path problem, which aims to find a path with the minimum cost-weighted length between two terminuses on a ratio-scaled raster cost surface, but the minimax (or maximin) path model is mathematically sounder if the cost values are measured on an ordinal scale and practically useful if the problem is concerned not with the minimization of cost but with the maximization of some desirable condition such as suitability. / Planerare som arbetar bland annat med att fatta beslut som hänsyftar till vissa lokaler använder ofta rasterbaserade geografiska informationssystem (GIS) för att sätta ett värde på marken med avseende på lämplighet eller kostnad för en viss användning. Ur en beräkningssynpunkt kan denna process ses som en transformation av en eller flera uppsättningar värden associerade med ett rutnät av celler till en annan uppsättning sådana värden genom en funktion som återspeglar ett eller flera kriterier. Medan det generellt förväntas att olika omvandlingar leder till olika "bästa" platser, har lite varit känt om hur sådana skillnader uppstår (eller inte uppstår). Exempel på sådana rumsliga beslutsproblem kan lätt hittas i litteraturen och många av dem handlar om valet av en uppsättning celler (som markanvändningen övervägs tilldelas) från en rasteryta av lämplighet eller kostnad beroende på kontext. För att underlätta GISs algoritmiska tillvägagångssätt antas det ofta att kvaliteten på uppsättningen av celler kan utvärderas som helhet genom summan av deras cellvärden. Giltigheten av detta antagande måste emellertid ifrågasättas om dessa värden mäts på en skala som inte tillåter aritmetiska transformationer. Användning av ordinal skala enligt Stevens typologi är ett exempel av detta. En fråga uppstår naturligt: Finns det ett mer matematiskt sunt och konsekvent tillvägagångssätt för att utvärdera kvaliteten på en rutt när kvaliteten på varje cell i det givna rutnätet mäts med ordinalskala? Avhandlingen försöker svara på ovanstående frågor i samband med ruttplanering genom en serie beräkningsexperiment med hjälp av ett antal slumpmässigt genererade landskapsnät med en rad olika rumsliga och icke-rumsliga strukturer. I den första uppsättningen experiment genererade vi minsta-kostnad rutter på ett antal kostnadsnät som transformerats från landskapsnätverket med hjälp av en mängd olika transformationsparametrar, och analyserade lägen och de (viktade) längderna för dessa rutter. Resultaten visar att samma par ändpunkter mycket väl kan vara sammanbundna med olika minsta-kostnad banor på olika kostnadsraster härledda från samma landskapsraster, och att variationen mellan dessa banor påverkas av hur givna värden fördelas i landskapsrastret såväl som av hur härledda värden fördelas i kostnadsrastret. Mest signifikant är att variationen tenderar att vara mindre när landskapsrastret innehåller mer distinkta grupper av celler som potentiellt lockar eller distraherar kostnadsbesparande passage, eller när kostnadsrastret innehåller ett mindre antal låg-kostnad celler. Den andra uppsättningen experiment syftar till att jämföra två optimeringsmodeller, minisum och minimax (eller maximin) sökmodeller, vilka sammanställer värdena för cellerna som är associerade med en sökväg med summanfunktionen respektive maximum (eller minimum) funktionen. Resultaten tyder på att minisumbanemodellen är effektiv om sökningen av sökvägen kan översättas till det konventionella minsta kostnadsproblemet, vilket syftar till att hitta en väg med den minsta kostnadsvägda längden mellan två terminaler på en ratio-skalad rasterkostyta, men minimax (eller maximin) banmodellen är matematiskt sundare om kostnadsvärdena mäts i ordinär skala och praktiskt användbar om problemet inte bara avser minimering av kostnad men samtidigt maximering av någon önskvärd egenskap såsom lämplighet. / <p>QC 20181002</p> Least-cost paths Most-suitable paths Raster cost surfaces Raster suitability surfaces Shortest path problem Minimax path problem Scales of measurement Minsta-kostnad rutter Mest-lämpliga rutter Raster kostnadsytor Raster lämplighets ytor kortaste vägen problem Minimax väg problem Mätskalor Geosciences, Multidisciplinary Multidisciplinär geovetenskap
145	GIS-based Episode Reconstruction Using GPS Data for Activity Analysis and Route Choice Modeling / GIS-based Episode Reconstruction Using GPS Data Dalumpines, Ron 26 September 2014 (has links) Most transportation problems arise from individual travel decisions. In response, transportation researchers had been studying individual travel behavior – a growing trend that requires activity data at individual level. Global positioning systems (GPS) and geographical information systems (GIS) have been used to capture and process individual activity data, from determining activity locations to mapping routes to these locations. Potential applications of GPS data seem limitless but our tools and methods to make these data usable lags behind. In response to this need, this dissertation presents a GIS-based toolkit to automatically extract activity episodes from GPS data and derive information related to these episodes from additional data (e.g., road network, land use). The major emphasis of this dissertation is the development of a toolkit for extracting information associated with movements of individuals from GPS data. To be effective, the toolkit has been developed around three design principles: transferability, modularity, and scalability. Two substantive chapters focus on selected components of the toolkit (map-matching, mode detection); another for the entire toolkit. Final substantive chapter demonstrates the toolkit’s potential by comparing route choice models of work and shop trips using inputs generated by the toolkit. There are several tools and methods that capitalize on GPS data, developed within different problem domains. This dissertation contributes to that repository of tools and methods by presenting a suite of tools that can extract all possible information that can be derived from GPS data. Unlike existing tools cited in the transportation literature, the toolkit has been designed to be complete (covers preprocessing up to extracting route attributes), and can work with GPS data alone or in combination with additional data. Moreover, this dissertation contributes to our understanding of route choice decisions for work and shop trips by looking into the combined effects of route attributes and individual characteristics. / Dissertation / Doctor of Philosophy (PhD) GPS time use diary episode extraction multinomial logit travel behavior mode detection episode reconstruction GIS map-matching route choice path size logit potential path area scale estimation Python ArcGIS activity analysis trip reconstruction smartphone global positioning system geographic information system toolkit work trip shop trip potential activity location land use activity episode travel episode stop episode transferability scalability modularity scripting big data travel survey respondent burden preprocessing multipath error tracking purpose detection segmentation data filter data smoothing fuzzy logic neural network decision tree rule-based algorithm trajectory point road network network dataset gateway shortest path horizontal dilution of precision HDOP commonality factor mode transfer point Halifax Nova Scotia Space-Time Activity Research variance inflation factor shapefile comma-separated values traveling salesman problem data mining branch-and-bound algorithm pedestrian network alternative route observed route route efficiency route attributes distance time heading bearing duration acceleration latitude longitude coordinate overlay analysis intersect shopping module data logger walk likelihood ratio test classification table path generation kappa statistic degrees data collection transportation research automate framework ArcToolbox spatio-temporal navigation positioning trace path spatial data topology horizontal accuracy SPSS Stata spatial resolution temporal resolution household survey trip reporting proximity analysis DMTI Desktop Mapping Technologies Inc. road intersection route overlap left turn right turn location analysis time geography spatial statistics buffer analysis cycling bus transit public transportation GEOIDE AGILE data need raw data urban canyon endpoint data cleaning elevation satellite outliers automatic processing nearest node classifier classification method short trip multi-point

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