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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

MagnetViz : design and evaluation of a physics-based interaction technique for graph visualization / MagnetViz : projeto e avaliação de uma técnica de interação baseada em física para visualização de grafos

Spritzer, Andre Suslik January 2009 (has links)
Esta dissertação apresenta MagnetViz, uma técnica para visualização de grafos. Enquanto a maior parte das técnicas visualizam um layout de grafo estático pre-computado, MagnetViz permite que usuários dinamicamente alterem o layout de um grafo de forma a melhor satisfazer suas necessidades. Isso é feito ao construir em cima da metáfora de física de algoritmos dirigidos à força para proporcionar aos usuários imãs virtuais, que podem atrair nodos que satisfazem um conjunto de critérios associados a eles. Critérios podem ser baseados na topologia ou semântica do grafo. Através de boundary shapes, que são simples formas geométricas que podem ser colocadas ao redor de imãs, usuários podem também definir regiões na cena onde os nodos atraídos devem permanecer. Grafos são descritos usando GraphML, uma linguagem baseada em XML, que permite a especificação dos nodos e arestas e de atributos para essas entidades. Após a submissão de um grafo como entrada, MagnetViz o exibe utilizando uma versão modificada do algoritmo clássico de Fruchterman and Rheingold, e permite que usuário, a seguir, insira imãs na cena. Usuários podem construir as condições associadas aos imãs utilizando os atributos dos nodos e arestas, além de atributos topológicos próprios de grafos. Para a avaliação de MagnetViz, foi primeiro analisado o desempenho da técnica ao ajudar usuários a executarem tarefas definidas por uma taxonomia de tarefas de visualização de grafos encontrada na literatura. Então, MagnetViz foi testada em um contexto prático através de um estudo de caso. Uma rede de co-autorias foi escolhida como conjunto de dados e o protótipo de MagnetViz foi inicialmente usado para responder questões relevantes a esses dados e então testado por um grupo de potenciais usuários, que tinham de usa-lo para responder essas mesmas perguntas. Após testar a aplicação, os sujeiotos receberam questionários sobre usas opiniões quanto a usabilidade, aplicabilidade, relevância e resultados visuais da técnica. Enquanto alguns aspectos da técnica ainda podem ser melhorados, os resultados da avaliação provaram que MagnetViz é uma abordagem válida para interação com visualizações de grafos. / This dissertation presents MagnetViz, a technique for the visualization of graphs. While most techniques visualize a static pre-computed graph layout, MagnetViz allows users to dynamically alter the layout of a graph to better satisfy their needs. This is done by building on the physics metaphor of force-directed algorithms to provide users with virtual magnets, which can attract nodes that fulfill a set of criteria associated with them. Criteria can be based on either the topology or semantics of the graph. Through boundary shapes, which are simple geometric shapes that can be placed around magnets, users can also define regions within the scene where the attracted nodes should remain. Graphs are described in GraphML, a XML-like description language which allows the specification of nodes and edges between nodes as well as attributes associated to nodes and edges. After loading a graph, Magnetviz displays it using a slightly modified version of the classical Fruchterman and Reingold' algorithm, and allows the user to insert magnets. Users can build the criteria associated with the magnets using the attributes of nodes and/or edges, besides the common graphs' topological attributes. For MagnetViz's evaluation, it was first analyzed how the technique fared in aiding users to perform tasks defined by a graph visualization task taxonomy described in the literature. Then, MagnetViz was tested within a practical context by means of a case study. A co-authorship network was chosen as the target dataset. The MagnetViz prototype was initially used to answer questions relevant to this dataset and then tested by a group of potential users, who had to use it to answer these same questions. After trying the application, subjects answered questionnaires about their opinion on the technique's usability, applicability, relevance and visual results. While some aspects of the technique should still be refined, results of the evaluation proved MagnetViz to be a valid approach when it comes to interaction with graph visualizations.
12

Product Layout Optimization for Autonomous Warehouses with Grouped Products

Nilsson, Max, Olsson, Hampus January 2020 (has links)
To utilize space better, warehouses stack their products on top of each other. This increases the risk of injury for workers when storing and retrieving the products. Some warehouses counteract this by using robots to retrieve products to a picking area where a human worker picks the products needed to fulfill an order. This means that it is important for the robots to be effective when retrieving products to reduce the time the worker spends waiting in the picking area. This thesis focuses on the grouping of products in the containers when they are stored in the warehouse. The robots will then retrieve one container at a time and if the grouping of products is done correctly this should decrease the number of retrievals required to fulfill an order. In order to make the decision on which products to group together, an application was developed that data mined previous orders that the warehouse had received in an attempt to extract information about the products. With the help of this information the application then suggests different product layouts that focus on different goals when they are created. The different layouts are then compared against each other in order to determine which layout technique produces the best results. This algorithm has been named the PLO-algorithm. The results showed that when a product is placed with the PLO-algorithm, the most important aspect to consider is the relations it has with the other products it is grouped with. The results also showed that data mining orders that are too old can have a negative impact on the result if not handled correctly. The results also showed that when constructing the warehouse you should try to avoid restrictions that affect which products can be placed together as much as possible since these restrictions can impact the effectiveness of the warehouse in a negative way. The thesis draws the conclusion that there is a clear gain in effectiveness for warehouses to have a planed layout for their products. It is recommended to data mine previous orders to extract relations between the products if possible since this piece of information showed the best results in this thesis. It is also in the warehouse best interest to avoid as many restrictions as possible that affect which products can be placed together since this can impact the results in a negative way. It is also beneficial to not include data that is too old in the data mining since this can impact the results in a negative way if not handled correctly. / För att utnyttja sitt utrymme bättre staplar lagerhus sina produkter på höjden. Detta medför högre risker för personskada vid hämtning och lämning av produkter, en del lagerhus löser detta genom att använda sig av robotar som hämtar och lämnar produkterna i lagerhuset. Robotarna hämtar och lämnar produkterna i en plock zon där en mänsklig arbetare plockar de produkter som behövs för en order. Detta innebär att det är viktigt att robotarna är effektiva i sin hämtning av produkter för att minska väntetiden för arbetarna i plock zonen. I ett försök att effektivisera robotarna fokuserar denna avhandling på gruperingen av produkterna i behållarna. Detta innebär att beslutet om vilka produkter som ska grupperas tillsammans i samma behållare är viktig eftersom om rätt produkter lagras tillsammans så kommer detta minska antalet hämtningar och lämningar som krävs för att uppfylla en beställning. För att hjälpa till med detta beslut skapades en applikation som analyserade tidigare beställningar som varuhuset erhållit i ett försök att extrahera information om produkterna. Applikationen skapar sedan olika förslag på produkt placeringar där de olika förslagen fokuserar på olika mål för att undersöka vilket mål som är viktigast att fokusera på när en produkt ska placeras. Algoritmen i denna applikation har valts att kallas för PLO-algoritmen. Resultaten visade att när en produkt ska placeras med PLO-algoritmen så är det viktigt att gruppera produkten med produkter den har starka relationer till. Resultatet visade också att när data ska analyseras bör inte för gammal data analyseras då äldre relationer mellan produkter som inte stämmer längre kan påverka resultatet negativt om algoritmen ej hanterar detta på något sätt. Resultaten visade också att vid konstruktionen av lagerhuset bör restriktioner som begränsar hur produkter kan placeras, undvikas om möjligt då dessa kan påverka lagerhusets effektivitet negativt. Slutsatsen som kan dras är att ett lagerhus kan tjäna väldigt mycket på att ha en plan när de bestämmer hur deras produkter ska placeras. Om det finns möjlighet att analysera tidigare beställningar efter relationer mellan produkter så är detta rekommenderat då det visade bäst resultat i denna undersökning. Det är även till lagerhusets fördel att försöka undvika restriktioner på deras lagersystem när det byggs eftersom det möjliggör för fler kombinationer när produkterna ska grupperas. Till sist så visar avhandlingen att med datan som användes att det var fördelaktigt att inte göra analys på för gammal data, då detta ger sämre resultat.
13

Responsive Web design : Ett fullvärdigt alternativ till plattformsspecifik utveckling?

Karlsson, Stefan, Michelle, Davis January 2013 (has links)
I och med lanseringen av nya och mobila plattformar, såsom smarttelefoner och surfplattor, uppstår svårigheter med att anpassa webbsidor för samtliga typer av enheter. Tidigare har mobila applikationer (appar) och mobila sidor använts för att överkomma dessa problem. Responsive Web Design (RWD) är en ung designprincip som uppkom 2010 och har anammats av många webbutvecklare. Designprincipen medför att en webbsidas presentation förändras beroende på skärmstorleken som används för att visa sidan. I en studie har fem företag intervjuats för att få deras tankar och åsikter om RWD i jämförelse med utveckling av mobila sidor och appar. Detta för att besvara huruvida RWD kan ersätta denna plattformsspecifika utveckling. Majoriteten av företagen har helt gått över till att utveckla responsiva webbsidor istället för andra mobilanpassningar men appar utvecklas fortfarande. Skiftet från mobila sidor beror främst på att denna typ av lösning kräver dubbelt arbete med innehållet då olika innehåll visas på olika enheter. Med RWD används istället samma innehåll över samtliga olika skärmtyper. Undersökningen visar på att RWD kan ersätta plattformsspecfik utveckling av informationssidor och e-tjänster. Däremot kommer det inte kunna ersätta appar då dessa i grunden fyller olika syften. Vid större krav på funktionalitet är dessvärre RWD inte alltid lämpligt att använda.
14

Manejo de cultivares de algodoeiro em densidade populacional variável com o uso de regulador de crescimento. / Management of cotton cultivars under variable plant densities using a plant growth regulator.

Zanon, Graciela Decian 28 November 2002 (has links)
Com o objetivo de estudar o comportamento fenológico, morfológico e produtivo de cultivares de algodoeiro com diferentes arquiteturas de plantas em diferentes espaçamentos, através do manejo com regulador de crescimento, foi realizado o presente trabalho, na área experimental da ESALQ/USP, no município de Piracicaba, Estado de São Paulo, no ano agrícola de 2000/01. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas sub-subdivididas e 4 repetições. As parcelas constituíram-se dos espaçamentos de 0,76 e 1,01 m, as subparcelas das três cultivares (IAC 23, DeltaOpal e CD 401) e as sub-subparcelas em presença ou ausência de regulador de crescimento. Em seis plantas marcadas de cada parcela foram analisados os seguintes parâmetros: acompanhamento das fases fenológicas (emergência, aparecimento do primeiro botão floral, antese da primeira flor e abertura do primeiro capulho) e caracteres agronômicos de campo (altura de planta, diâmetro do caule, número de ramos vegetativos e frutíferos, conformação da planta, número de capulhos por planta e altura de inserção do primeiro ramo frutífero). Na área útil de cada parcela foi determinada, a produção de algodão em caroço por hectare e a precocidade de colheita. Em amostras de 20 capulhos tomadas aleatoriamente em cada parcela foram realizadas as análises dos caracteres agronômicos de laboratório (massa de 100 sementes, porcentagem de fibras e massa média de um capulho) e das características tecnológicas da fibra (comprimento, uniformidade de comprimento, maturidade, tenacidade e índice micronaire). Os resultados obtidos permitem concluir que não houve interações significativas para as cultivares x espaçamentos x regulador de crescimento, para a produção de algodão em caroço, precocidade de colheita, caracteres agronômicos de laboratório e características tecnológicas das fibras, com exceção da tenacidade. Desta forma, as cultivares avaliadas, independente da arquitetura da planta, apresentaram capacidade de ajustar-se às variações dos espaçamentos testados e aplicação de regulador de crescimento com relação a estas características. Os caracteres agronômicos de campo como: a altura das plantas e o diâmetro de caule, de modo geral, apresentaram médias reduzidas com a redução do espaçamento e aplicação do regulador de crescimento, para as cultivares de desenvolvimento mais vigoroso (IAC 23 e DeltaOpal), não influenciando, porém, a cultivar de plantas morfologicamente mais compactas (CD 401). / The purpose of this work was to study the phenological, morphological and productive behavior of cotton cultivars presenting different plant shapes under different spacing layouts managed with the use of plant growth regulator. The experiment was established in the experimental field of ESALQ/USP, Piracicaba, Sao Paulo, during the 2000/01 growing season and was arranged in a randomized block experimental design with subdivided plots and 4 replications. The plots represented spacing layouts of 0.76 and 1.01 m, subplots consisted of the IAC 23, DeltaOpal and CD 401 cultivars, while the sub-subplots were characterized by the use or absence of growth regulator. Six plants per plot were labeled and analyzed for the phenological phases (emergence, appearance of the first flower bud, anthesis of the first flower, opening of the first cotton boll) and field agronomical characteristics (plant height, stem diameter, number of vegetative and fruit branches, plant shape, number of cotton boll per plant and insertion height of the first fruit branch). The harvest early and raw cotton yield per hectare were determined considering the effective plot area. The agronomical lab characteristics (mass of 100 seeds, fiber percentage and cotton boll mass), as well as the fiber technological characteristics (length, length uniformity, maturity, strength, and micronaire) were analyzed using a sample of 20 bolls taken at random. Based on the results obtained, it can be concluded that there were no significant interactions among cultivars x spacing x growth regulator, as to cotton yield, harvest early, agronomical lab characteristics and fiber technological characteristics, except for stremgth. The analyzed cultivars, regardless of the plant shape, showed good adaptation to the variation in spacing layouts, as well as to the application of growth regulator, considering the analyzed characteristics. The field agronomical characteristics, such as plant height and stem diameter, generally decreased with the reduction in spacing and with the application of growth regulator, considering the most vigorous cultivars (IAC 23 and DeltaOpal). On the other hand, the cultivar presenting a more compact plant (CD 401) pattern was not influenced by spacing or use of growth regulator.
15

Quatro décadas de grandes expansões planejadas na capital paraibana (1913-1953).

Ressa, Patricia Gigliola de Queiroga 28 September 2012 (has links)
Made available in DSpace on 2015-05-14T12:09:12Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 10002262 bytes, checksum: 076b1398c610f993f356d94a37cd0774 (MD5) Previous issue date: 2012-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work shows (a) how the urban extensions covering 50 or more hectares contributed to the physical growth of João Pessoa, the capital of Paraíba, Brazil, between 1913 and 1953, and (b) that they generated most of the urban and suburban fabric that was added to the town in that period of time. It analyzes in depth these additions, treating aspects such as features of the site, layout characteristics and integration between the layout and the nearby tissues. Such a study had not been conducted yet and is essential for the local urban history. The theoretical basis of the dissertation is the analysis of over twenty large extensions planned in Europe and the Americas which it presents. The method adopted for the carrying out of the most relevant part of the study of the additions was the morphological analysis of their layout. Seven extensions added 770 hectares to the town between 1913 and 1953, which is over 50% of its overall extension in that period. Curiously the two extension plans which were not implemented were just those designed by two famous Brazilian town-planners: Saturnino de Brito and Nestor de Figueiredo. / Esta dissertação mostra (a) como as expansões planejadas com 50 ou mais hectares contribuíram para o crescimento físico da capital paraibana entre 1913 e 1953 e (b) que foram elas a origem da maior parte do tecido urbano ou suburbano agregado à cidade nesse período. Ela analisa com profundidade essas ampliações, tratando as-pectos como traços geográficos do sítio planejado, características do traçado e seu nível de integração com os tecidos adjacentes. Tal estudo não havia sido feito ainda e é essencial para a história urbanística de João Pessoa. O alicerce teórico da disserta-ção é o exame que ela fez de mais de vinte grandes expansões projetadas na Europa e nas Américas até 1910. O método adotado para a realização da parte mais relevante do estudo das expansões foi a análise morfológica dos seus planos. Sete grandes am-pliações agregaram 770 hectares à cidade entre 1913 e 1953, o que é mais da metade da expansão total dela nesse intervalo. Dois planos de expansão não se concre-tizaram, exatamente os concebidos por dois urbanistas respeitados: Saturnino de Brito e Nestor de Figueiredo.
16

Manejo de cultivares de algodoeiro em densidade populacional variável com o uso de regulador de crescimento. / Management of cotton cultivars under variable plant densities using a plant growth regulator.

Graciela Decian Zanon 28 November 2002 (has links)
Com o objetivo de estudar o comportamento fenológico, morfológico e produtivo de cultivares de algodoeiro com diferentes arquiteturas de plantas em diferentes espaçamentos, através do manejo com regulador de crescimento, foi realizado o presente trabalho, na área experimental da ESALQ/USP, no município de Piracicaba, Estado de São Paulo, no ano agrícola de 2000/01. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas sub-subdivididas e 4 repetições. As parcelas constituíram-se dos espaçamentos de 0,76 e 1,01 m, as subparcelas das três cultivares (IAC 23, DeltaOpal e CD 401) e as sub-subparcelas em presença ou ausência de regulador de crescimento. Em seis plantas marcadas de cada parcela foram analisados os seguintes parâmetros: acompanhamento das fases fenológicas (emergência, aparecimento do primeiro botão floral, antese da primeira flor e abertura do primeiro capulho) e caracteres agronômicos de campo (altura de planta, diâmetro do caule, número de ramos vegetativos e frutíferos, conformação da planta, número de capulhos por planta e altura de inserção do primeiro ramo frutífero). Na área útil de cada parcela foi determinada, a produção de algodão em caroço por hectare e a precocidade de colheita. Em amostras de 20 capulhos tomadas aleatoriamente em cada parcela foram realizadas as análises dos caracteres agronômicos de laboratório (massa de 100 sementes, porcentagem de fibras e massa média de um capulho) e das características tecnológicas da fibra (comprimento, uniformidade de comprimento, maturidade, tenacidade e índice micronaire). Os resultados obtidos permitem concluir que não houve interações significativas para as cultivares x espaçamentos x regulador de crescimento, para a produção de algodão em caroço, precocidade de colheita, caracteres agronômicos de laboratório e características tecnológicas das fibras, com exceção da tenacidade. Desta forma, as cultivares avaliadas, independente da arquitetura da planta, apresentaram capacidade de ajustar-se às variações dos espaçamentos testados e aplicação de regulador de crescimento com relação a estas características. Os caracteres agronômicos de campo como: a altura das plantas e o diâmetro de caule, de modo geral, apresentaram médias reduzidas com a redução do espaçamento e aplicação do regulador de crescimento, para as cultivares de desenvolvimento mais vigoroso (IAC 23 e DeltaOpal), não influenciando, porém, a cultivar de plantas morfologicamente mais compactas (CD 401). / The purpose of this work was to study the phenological, morphological and productive behavior of cotton cultivars presenting different plant shapes under different spacing layouts managed with the use of plant growth regulator. The experiment was established in the experimental field of ESALQ/USP, Piracicaba, Sao Paulo, during the 2000/01 growing season and was arranged in a randomized block experimental design with subdivided plots and 4 replications. The plots represented spacing layouts of 0.76 and 1.01 m, subplots consisted of the IAC 23, DeltaOpal and CD 401 cultivars, while the sub-subplots were characterized by the use or absence of growth regulator. Six plants per plot were labeled and analyzed for the phenological phases (emergence, appearance of the first flower bud, anthesis of the first flower, opening of the first cotton boll) and field agronomical characteristics (plant height, stem diameter, number of vegetative and fruit branches, plant shape, number of cotton boll per plant and insertion height of the first fruit branch). The harvest early and raw cotton yield per hectare were determined considering the effective plot area. The agronomical lab characteristics (mass of 100 seeds, fiber percentage and cotton boll mass), as well as the fiber technological characteristics (length, length uniformity, maturity, strength, and micronaire) were analyzed using a sample of 20 bolls taken at random. Based on the results obtained, it can be concluded that there were no significant interactions among cultivars x spacing x growth regulator, as to cotton yield, harvest early, agronomical lab characteristics and fiber technological characteristics, except for stremgth. The analyzed cultivars, regardless of the plant shape, showed good adaptation to the variation in spacing layouts, as well as to the application of growth regulator, considering the analyzed characteristics. The field agronomical characteristics, such as plant height and stem diameter, generally decreased with the reduction in spacing and with the application of growth regulator, considering the most vigorous cultivars (IAC 23 and DeltaOpal). On the other hand, the cultivar presenting a more compact plant (CD 401) pattern was not influenced by spacing or use of growth regulator.
17

Evaluating Layouts for Automated Transport System using Simulation Approach

Rashid, Rizwan, Kaleem, Babur January 2009 (has links)
Industries such as trade, manufacturing and transportation have undergone significant changes due to the globalization concept. Sea ports play a very important role in building and strengthening the economies of countries worldwide. Due to the high rate of production, the work load has increased at the ports which resulted into financial as well as capacity problems. As a result of such problems, cost optimized and automated solutions are being developed and introduced at the ports. In the horizontal transport system of the sea ports, AGVs are one of those automated solutions used to transport containers from ships to yard and vice versa. Newer and more practices are being employed to make the efficient transportation of these AGVs. Numexia has recently introduced a new version of Cassette AGVs called Zero-Emission C-AGV. A conceptual model is developed for Zero-Emission C-AGVs and different layouts are evaluated using multi agent-based simulation. The greedy algorithm has been used for the efficient dispatching of jobs. The Simulation will carry out the dispatching of jobs for C-AGVs between quay area and yard using different layouts and scenarios for the unloading operation.
18

Meny layouter inom e-handelsbutiker / Menu layouts within e-commerce shops

Makhoul, Amanda January 2020 (has links)
There are multiple ways to build a menu within an e-commerce site. In the study performed by J. Hamblin, & Barbara S. Chaparro (2003) it was shown that the users prefered the Index menu over the corresponding horizontal and vertical menu layouts due to the fact that they could perform their tasks faster and easier on that menu. In this study different menus were tested within an e-commerce site to see whether or not this result still applies today. However, in addition, the usage of images within menus would be an addition to test to see whether or not images affect the results. However in this study, the different users are divided into three groups to differ their preference. Those with little, medium and a lot of experience with computers. The hypothesis was that the Index Image menu would be the most preferred and that images would decrease the amount of time it takes forusers to perform their tasks. The hypothesis was to be only partly right. Result shows that the horizontal menu containing images was mostly preferred by allgroups even though it was not the fastest menu among all of them to use showing that images did not necessarily lower the time it takes to perform tasks. The result also shows that the group with the least amount of computer experience also had a preference for the Image Index menu which does agree with the hypothesis, but however, this only applied to one group therefore the hypothesis can not be considered completely correct in that aspect. However, the experiment proves that there is a preference for images within these menus.
19

Preserving the Mental Map when Visualizing Dynamic Graphs : An Approach for Intermediate Representations in the C2 Java Compiler / Bevarande av den mentala kartan vid visualisering av dynamiska grafer : Ett tillvägagångssätt för mellanrepresentationer i C2 Java-kompilatorn

Yin, Emmy January 2023 (has links)
Graphs are powerful data structures that are widely used to represent complex forms of information. One area in which graphs are successfully being used is within compiler engineering, where a program under compilation can be represented as a graph that changes as the program is being compiled. These graphs, known as Intermediate Representation graphs, can be visualized to aid compiler engineers in understanding and debugging the compiler. However, graphs that change over time need to be visualized so that the viewer’s internal understanding of the graph is maintained. Simultaneously, the graph layouts should be of high quality. These criteria can be conflicting, making the visualization of changing graphs difficult. In this thesis, a dynamic graph layout algorithm to visualize dynamic Intermediate Representation graphs used in the C2 compiler in the Java HotSpotTM Virtual Machine was developed and evaluated. Currently, these graphs are visualized with hierarchical layouts, using a static graph layout algorithm. Five metrics were developed and used to evaluate the layouts by the dynamic algorithm against the layouts by the static algorithm. Four of these were concerned with the layout quality, by measuring the number of edge crossings, number of reversed edges, average degree of the edge bends and the average edge length. The fifth metric was related to mental map preservation and measures the Euclidean distance of node displacement across two layouts. Two experiments were conducted to compare the algorithms. The first experiment measured the layouts drawn by the algorithms when there were a couple of nodes added to or removed from a graph iteratively. A total of 1061 layouts were measured. In 74% of these, the dynamic algorithm caused less node displacement. The second experiment aimed to evaluate the algorithms against what is possible to achieve in regards of minimum node displacement while maintaining a high quality. The results of both experiments indicate that the dynamic layout algorithm yields layouts with less node displacement. However, the layouts generally have more reversed edges, more bends in the edges and overall longer edges. These metrics worsened as more iterations of changes were applied. The findings suggest that the dynamic layout algorithm is better at preserving the mental map, but at the cost of the layout quality. / Grafer är kraftfulla datastrukturer som används för att representera komplexa former av information. Ett område där grafer framgångsrikt används är inom kompilatorutveckling, där ett program under kompilering kan representeras som en graf som förändras medan programmet kompileras. Sådana grafer, kända som mellanrepresentationsgrafer, kan visualiseras för att hjälpa kompilatoringenjörer att förstå och felsöka kompilatorn. Dock behöver grafer som ändras över tid visualiseras så att användarens interna förståelse av grafen bibehålls. Samtidigt bör grafens layout vara av hög kvalitet. Dessa kriterier kan vara motsägelsefulla och gör visualiseringen av föränderliga grafer svår. I denna avhandling utvecklades och utvärderades en dynamisk layoutalgoritm för att visualisera dynamiska mellanrepresentationsgrafer som används i C2-kompilatorn i Java HotSpotTM Virtual Machine. Idag visualiseras dessa grafer med hierarkiska layouter som ritas av en statisk layoutalgoritm. Fem mått utvecklades och användes för att jämföra layouterna ritade av den dynamiska algoritmen med layouterna ritade av den statiska algoritmen. Fyra av dessa var relaterade till layoutkvaliteten och mäter antalet korsningar mellan kanter, antalet omvända kanter, den genomsnittliga graden av kantböjningar och den genomsnittliga kantlängden. Det femte måttet är relaterat till bevarandet av den mentala kartan och mätte nodförskjutningen mellan två layouter. Två experiment genomfördes för att jämföra algoritmerna. Det första experimentet mätte layouterna som ritades av algoritmerna när ett par noder lades till eller togs bort från en graf iterativt. Totalt mättes 1061 layouter. I 74% av dessa orsakade den dynamiska algoritmen mindre nodförskjutning. Det andra experimentet syftade till att utvärdera algoritmerna med avseende på minimal nodförskjutning samtidigt som hög kvalitet bibehålls. Resultaten från båda experimenten indikerar att den dynamiska layoutalgoritmen ger layouter med mindre nodförskjutning. Layouterna har dock generellt sett fler omvända kanter, fler böjningar i kanterna och längre kanter. Dessa mått försämrades när fler iterationer av förändringar tillämpades. Resultaten tyder på att den dynamiska layoutalgoritmen är bättre på att bevara den mentala kartan, men på bekostnad av layoutkvaliteten.
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Generation of semantic layouts for interactive multidimensional data visualization / Geração de layouts semânticos para a visualização interativa de dados multidimensionais

Gomez Nieto, Erick Mauricio 24 February 2017 (has links)
Visualization methods make use of interactive graphical representations embedded on a display area in order to enable data exploration and analysis. These typically rely on geometric primitives for representing data or building more sophisticated representations to assist the visual analysis process. One of the most challenging tasks in this context is to determinate an optimal layout of these primitives which turns out to be effective and informative. Existing algorithms for building layouts from geometric primitives are typically designed to cope with requirements such as orthogonal alignment, overlap removal, optimal area usage, hierarchical organization, dynamic update among others. However, most techniques are able to tackle just a few of those requirements simultaneously, impairing their use and flexibility. In this dissertation, we propose a set of approaches for building layouts from geometric primitives that concurrently addresses a wider range of requirements. Relying on multidimensional projection and optimization formulations, our methods arrange geometric objects in the visual space so as to generate well-structured layouts that preserve the semantic relation among objects while still making an efficient use of display area. A comprehensive set of quantitative comparisons against existing methods for layout generation and applications on text, image, and video data set visualization prove the effectiveness of our approaches. / Métodos de visualização fazem uso de representações gráficas interativas embutidas em uma área de exibição para exploração e análise de dados. Esses recursos visuais usam primitivas geométricas para representar dados ou compor representações mais sofisticadas que facilitem a extração visual de informações. Uma das tarefas mais desafiadoras é determinar um layout ótimo visando explorar suas capacidades para transmitir informação dentro de uma determinada visualização. Os algoritmos existentes para construir layouts a partir de primitivas geométricas são tipicamente projetados para lidar com requisitos como alinhamento ortogonal, remoção de sobreposição, área usada, organização hierárquica, atualização dinâmica entre outros. No entanto, a maioria das técnicas são capazes de lidar com apenas alguns desses requerimentos simultaneamente, prejudicando sua utilização e flexibilidade. Nesta tese, propomos um conjunto de abordagens para construir layouts a partir de primitivas geométricas que simultaneamente lidam com uma gama mais ampla de requerimentos. Baseando-se em projeções multidimensionais e formulações de otimização, os nossos métodos organizam objetos geométricos no espaço visual para gerar layouts bem estruturados que preservam a relação semântica entre objetos enquanto ainda fazem um uso eficiente da área de exibição. Um conjunto detalhado de comparações quantitativas com métodos existentes para a geração de layouts e aplicações em visualização de conjunto de dados de texto, imagem e vídeo comprova a eficácia das técnicas propostas.

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