abstract: Given that more and more planned special events are hosted in urban areas, during which travel demand is considerably higher than usual, it is one of the most effective strategies opening public rapid transit lines and building park-and-ride facilities to allow visitors to park their cars and take buses to the event sites. In the meantime, special event workforce often needs to make balances among the limitations of construction budget, land use and targeted travel time budgets for visitors. As such, optimizing the park-and-ride locations and capacities is critical in this process of transportation management during planned special event. It is also known as park-and-ride facility design problem. This thesis formulates and solves the park-and-ride facility design problem for special events based on space-time network models. The general network design process with park-and-ride facilities location design is first elaborated and then mathematical programming formulation is established for special events. Meanwhile with the purpose of relax some certain hard constraints in this problem, a transformed network model which the hard park-and-ride constraints are pre-built into the new network is constructed and solved with the similar solution algorithm. In doing so, the number of hard constraints and level of complexity of the studied problem can be considerable reduced in some cases. Through two case studies, it is proven that the proposed formulation and solution algorithms can provide effective decision supports in selecting the locations and capabilities of park-and-ride facilities for special events. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2016

Historicamente, os concursos públicos de projetos de Arquitetura e Urbanismo produzem material que apresentam diferentes soluções a um mesmo problema. Do edital até a seleção de projetos, o concurso é um processo que permite oportunidades de investigação por meio de vários enfoques. Cientes da importância da produção intelectual resultante desses concursos, pesquisadores da UNIRITTER e UFRGS, em parceria com o Instituto de Arquitetos do Brasil – Departamento do Rio Grande do Sul (IAB/RS), formataram um Acervo que contém o material de concursos realizados no Rio Grande do Sul. Esta pesquisa é inspirada em parte do conteúdo desse Acervo. O foco desta pesquisa está sobre resultados de análises que investigam a influência da formulação do problema em soluções projetuais das propostas classificadas em Concursos de Projetos Urbanos no RS, selecionados entre 2006 e 2016. Para desenvolver a metodologia da pesquisa, utilizou fundamentos do Design Thinking, uma abordagem que permite focar tanto no usuário quanto no problema em si, objetivando soluções mais precisas. Assim, esta pesquisa analisou o problema e a solução para Projetos Urbanos, propondo uma Matriz de Análise a partir de fundamentos da abordagem do Design Thinking. As bases dos concursos foram consideradas a proposição do problema, enquanto os resultados dos concursos, ou seja, os projetos classificados, foram utilizados como o valor gerado pelo concurso. O processo de comparação entre bases dos concursos (proposição do problema) e solução (projetos classificados/atas de julgamento) foi determinado como a incógnita da equação. Desse modo, se estabeleceu a questão de pesquisa que questionou a influência da proposição do problema sobre a resposta em Projetos Urbanos resultantes de concursos. Por meio do uso de ferramentas de análise da retórica da linguagem verbal e visual, aplicadas tanto sobre as bases dos concursos selecionados, quanto nas propostas projetuais classificadas, a pesquisa comparou o problema (bases dos concursos), as soluções propostas (projetos) e a seleção do júri (classificação). A investigação foi dividida em quatro etapas principais, na qual a primeira se concentrou em explorar o Acervo e desenvolver critérios de seleção de amostra, além de fundamentar a pesquisa por meio de revisão de literatura; a segunda etapa teve o foco voltado para o desenvolvimento da Matriz de Análise e seleção e aplicação de ferramentas de retórica verbal e visual; a terceira etapa foi o momento de tabulação e análise de dados; a quarta e última etapa da pesquisa foi a base para a consolidação dos dados e análise dos resultados. A principal contribuição da pesquisa foi misturar métodos de diferentes abordagens para entender a relação entre problema e solução em Projeto Urbano, o que pode revelar meios para uma melhor elaboração do problema de projeto em concursos futuros. Além disso, fomenta o debate sobre a formulação dos problemas em Projetos Urbanos de concursos públicos. O estudo também apresentou recomendações para melhoria da composição de acervo existente e estudos futuros. / Historically, public tendering for Architecture and Urbanism projects produce material that show different solutions to the same problem. From the public notice to the project selection, public tendering is a process that permits investigation opportunities via plenty of approaches. Aware of the importance of the intellectual production that results from these public tenderings, UNIRITTER and UFRGS researchers, along with the Brazilian Architects’ Institute – Rio Grande do Sul section (IAB/RS), formulated a archive that contains the material made in public tenderings in Rio Grande do Sul. This research is inspired in part of this archive. The focus of this research is about the results of analysis that investigate the influence the formulation of the problem in projectual solutions of the classified propositions classified in urban project public tenderings in Rio Grande do Sul, selected between 2006 and 2016. To develop the research methodology, we used fundamentals of Design Thinking, an approach that allows to focus on the user and also on the proble itself, aiming for more precise solutions. So, this research analyzed the problem and solution for Urban Projects, proposing a matrix of analysis on the basis of Design Thinking Approach. The public tendering bases were considered as the proposition of the problem, while the results of the exams, that is, the classified projects, were used as the value generated by the tendering. The comparative process between tendering basis (proposition of the problem) and solution (classified projects/adjudgment acts) was determine as the unknown element of the equation. In that way, it was established that the research question that questioned the proposition of the problem’s influence over the answer in Urban Project that resulted from public exams. Through the use of tools of analysis of rhetoric of verbal and visual language, applied over the bases of the selected tendering, and also on the classified projectual propositions, this research compares the problem (public tendering basis), the proposed solutions (projects) and the jury selection (classification). The investigation was divided in four main stages, in which the first focused on exploring the archive and develop sample selection criteria, also fundamenting the research by means of literature revision; the second stage focused on the development of the matrix of analysis, selection and application of tools of analysis of rhetoric of verbal and visual language; the third stage was the tabulation and data analysis; the fourth and last research stage was the basis of the data consolidation and analysis of the results. The main contribution of the research was to show methods of different approaches to understand the relation between problem and solution in Urban Projects, something that can reveal means to a better elaboration of the project’s problem in future public tenderings. Also, it stimulates the debate about the formulation of problems in Urban Projects public tenderings. This research also shows recommendations to improve the composition of the existing archive and its future studies.

Real-life transportation systems are subject to numerous uncertainties in their operation. Researchers have suggested various reliability measures to characterize their network-level performances. One of these measures is given by travel time reliability, defined as the probability that travel times remain below certain (acceptable) levels. Existing reliability assessment (and optimization) techniques tend to be computationally intensive. In this dissertation we develop computationally efficient alternatives. In particular, we make the following three contributions. In the first contribution, we present a novel reliability assessment methodology when the source of uncertainty is given by road capacities. More specifically, we present a method based on the theory of Fourier transforms to numerically approximate the probability density function of the (system-wide) travel time. The proposed methodology takes advantage of the established computational efficiency of the fast Fourier transform. In the second contribution, we relax the common assumption that probability distributions of the sources of uncertainties are known explicitly. In reality, this distribution may be unavailable (or inaccurate) as we may have no (or insufficient) data to calibrate the distributions. We present a new method to assess travel time reliability that is distribution-free in the sense that the methodology only requires that the first N moments (where N is any positive integer) of the travel time to be known and that the travel times reside in a set of known and bounded intervals. Instead of deriving exact probabilities on travel times exceeding certain thresholds via computationally intensive methods, we develop analytical probability inequalities to quickly obtain upper bounds on the desired probability. Because of the computationally intensive nature of (virtually all) existing reliability assessment techniques, the optimization of the reliability of transportation systems has generally been computationally prohibitive. The third and final contribution of this dissertation is the introduction of a new transportation network design model in which the objective is to minimize the unreliability of travel time. The computational requirements are shown to be much lower due to the assessment techniques developed in this dissertation. Moreover, numerical results suggest that it has the potential to form a computationally efficient proxy for current simulation-based network design models. / text

In this dissertation, we examine specific network connectivity problems, and achieve improved approximation algorithm and integrality gap results for them. We introduce an important new, highly useful and applicable, network connectivity problem - the Vital Core Connectivity Problem (VCC). Despite its many practical uses, this problem has not been previously studied. We present the first constant factor approximation algorithm for VCC, and provide an upper bound on the integrality gap of its linear programming relaxation. We also introduce a new, useful, extension of the minimum spanning tree problem, called the Extended Minimum Spanning Tree Problem (EMST), that is based on a special case of VCC; and provide both a polynomial-time algorithm and a complete linear description for it. Furthermore, we show how to generalize this new problem to handle numerous disjoint vital cores, providing the first complete linear description of, and polynomial-time algorithm for, the generalized problem. We examine the Survivable Network Design Problem (SNDP) with multiple copies of edges allowed in the solution (multi-SNDP), and present a new approximation algorithm for which the approximation guarantee is better than that of the current best known for certain cases of multi-SNDP. With our method, we also obtain improved bounds on the integrality gap of the linear programming relaxation of the problem. Furthermore, we show the application of these results to variations of SNDP. We investigate cases where the optimal values of multi-SNDP and SNDP are equal; and we present an improvement on the previously best known integrality gap bound and approximation guarantee for the special case of SNDP with metric costs and low vertex connectivity requirements, as well as for the similar special case of the Vertex Connected Survivable Network Design Problem (VC-SNDP). The quality of the results that one can obtain for a given network design problem often depends on its integer linear programming formulation, and, in particular, on its linear programming relaxation. In this connection, we investigate formulations for the Steiner Tree Problem (ST). We propose two new formulations for ST, and investigate their strength in terms of their associated integrality gaps.

This thesis assumes the architectural design process as a systematic study, in which knowledge is stored, organized and operated on by computational methods. From this perspective, the study explores the efforts for systemizing the architectural design process. Firstly, the focus is on the early approaches of systemizing design in the Design Methods Movement. The thesis identifies and evaluates the use of a number of critical concepts in this movement and in recent architecture practice, in order to see the development and transformation of design methods in terms of computing knowledge in a systematic way. The thesis evaluates the features that make design systematic within the Design Methods Movement and inquires whether such features like complexity, hierarchy, feedback loops and selection are influential in recent computational design methods of architecture. The thesis looks into two generative design methods, namely evolutionary design and shape grammars, which have been studied by designers since the 1960s, the start of the Design Methods Movement. These two methods exemplify current systematic approaches to design and according to the thesis these are the instances of how recent architecture employs the features discussed as characteristic in the Design Methods Movement.

Due to its economic importance engineering design as a creative design problem solving has been the research subject of psychologists and design engineers for several years. Observations of designer's thinking and action processes show that especially in the early stages of the design process, in which requirements are clarified and ideas are developed, generating solutions is largely associated with the use of simple external representations such as sketches and material (physical) models. In the represented thesis the use and functions of such external aids were investigated at first with a questionnaire study consulting designers (N = 106) of different industries. The results demonstrate the dominance of sketches as well as the increasing use of CAD already in the early stages of product development. In contrast models are applied to a lesser extent. Thereby simple external aids are not only used as memory-relieving external information storages, but do also support solution development and testing, serve as an analysis aid and contribute helpfully to documentation and communication. Further in an experimental study the use and functions of sketching and manual modelling applied by engineering students and designers (N = 61) while working on two design problems of different complexity with free choice of the support form were analysed. The results verify the essential importance of sketching for the design process, since almost all subjects used sketches to deal with the two design problems, while material models were hardly applied. Again the sketches fulfil different functions, so besides documentation they mainly support solution development. These statement based findings that sketches in addition to their function as external storages for memory relief serve also as thinking aids, thus support the generating and further developing of solution concepts, could be confirmed by observation data based on the analysis of the individual design processes. Finally recommendations for the design of new and advanced computer-assisted design aids could be given. / Das Konstruieren als schöpferisch-entwerfendes Problemlösen (design problem solving) ist aufgrund seiner wirtschaftlichen Bedeutung seit längerem Gegenstand der Forschung von Psychologen und Konstruktionswissenschaftlern. Beobachtungen des Vorgehens des Konstrukteurs zeigen, daß insbesondere in den frühen Phasen des konstruktiven Entwurfsprozesses, in denen Anforderungen geklärt und Ideen generiert werden, die Lösungsentwicklung in hohem Maße durch einfache externe Hilfsmittel, wie Skizzen und gegenständliche Modelle, unterstützt wird. In der dargestellten Dissertation wurde Einsatz und Nutzen dieser Hilfsmittel zunächst anhand einer Befragung von Konstrukteuren (N = 106) verschiedener Branchen untersucht. Die Ergebnisse belegen die Dominanz von Skizzen sowie die Zunahme der Nutzung von CAD bereits in den frühen Phasen der Produktentwicklung. Modelle finden dagegen weniger häufig Verwendung. Einfache externe Hilfsmittel werden dabei nicht nur als gedächtnisentlastende externe Speicher eingesetzt, sondern unterstützen ebenso die Lösungsentwicklung und -überprüfung, dienen als Analysehilfe und tragen hilfreich zur Dokumentation und Kommunikation bei. Weiterhin wurde in einer experimentellen Studie der Einsatz und die Funktionen des Skizzierens und manuellen Modellierens bei der Bearbeitung zweier Konstruktionsprobleme unterschiedlicher Komplexität durch Maschinenbaustudenten und Konstrukteure (N = 61) bei freier Wahl der Unterstützungsform näher untersucht. Die Ergebnisse verifizieren die essentielle Bedeutung des Skizzierens für den konstruktiven Entwurfsprozeß, da nahezu alle Probanden die beiden Konstruktionsprobleme von Anfang an skizzierend bearbeiteten, während einfache Modelle so gut wie gar nicht eingesetzt wurden. Die Skizzen erfüllten wiederum verschiedene Funktionen, neben der Dokumentation wurden sie v.a. zur Lösungsentwicklung verwendet. Dabei konnten diese auf Aussagen beruhenden Erkenntnisse, daß Skizzen neben der Gedächtnisentlastung auch eine Denkhilfe bieten, durch aus der Analyse der Entwurfsprozesse gewonnene Beobachtungsdaten bestätigt werden. Abschließend wurden Gestaltungsempfehlungen für die Neu- und Weiterentwicklung computergestützter Hilfsmittel des konstruktiven Entwurfsprozesses formuliert.

Network design decisions, especially those pertaining to urban infrastructure, are made by a central authority or network leader, and taking into consideration the network users or followers. These network decision problems are formulated as non-linear bi-level programming problems. In this work, a continuous network design problem (CNDP) and discrete network design problem (DNDP) bi-level optimization programs are proposed and solved in the context of transportation planning. The solution strategy involved reformulation and linearization as a single-level program by introducing the optimality conditions of the lower level problem into the upper level problem. For the CNDP, an alternative linearization algorithm (modified least squares partitioning, MLSPA) is proposed. MLSPA takes into consideration the current arc capacity and potential expansion to find a reduced set of planes to generalize the flow-capacity surface behavior. The concepts of flow capacity surface was introduced as a way to model of congested network and capture the effect of capacity on travel time/cost. It was found that the quality of the linear approximation depends on the goodness of fit the bottleneck arcs. The proposed approach was tested with well-known benchmark problems in transportation which yielded promising results in terms of efficiency, without sacrificing solution quality.

Biologically inspired design (BID) is a widespread and growing movement in modern design, pulled in part by the need for environmentally sustainable design and pushed partly by rapid advances in biology and the desire for creativity and innovation in design. Yet, our current understanding of cognition in BID is limited and at present there are few computational methods or tools available for supporting its practice. In this dissertation, I develop a cognitive model of BID, build computational methods and tools for supporting its practice, and describe results from deploying the methods and the tools in a Georgia Tech BID class. One key and novel finding in my cognitive study of BID is the surprisingly large degree to which biological analogues influence problem formulation and understanding in addition to generation of design solutions. I call the process by which a biological analogue influences the evolution of the problem formulation analogical problem evolution. I use the method of grounded theory to develop a knowledge schema called SR.BID (for structured representations for biologically inspired design) for representing design problem formulations. I show through case study analysis that SR.BID provides a useful analytic framework for understanding the two-way interaction between problems and solutions. I then develop two tools based on the SR.BID schema to scaffold the processes of problem formulation and analogue evaluation in BID. I deployed the two tools, the four-box method of problem specification and the T-chart method of analogical evaluation, in a Georgia Tech BID class. I show that with minimal training, the four-box method was used by students to complete design problem specifications in 2011 and 2012 with 75% of students achieving better than 80% accuracy. Finally I describe a web-based application for interactively supporting BID practice including problem formulation and analogue evaluation. Thus, my dissertation develops a cognitive model of analogical problem evolution in BID, a knowledge schema for representing problem formulations, a computational technique for evaluating biological analogues, and an interactive web-based tool for supporting BID practice. Through a better cognitive understanding of BID and computational methods and tools for supporting its practice, it also contributes to computational creativity.

In this dissertation, we examine specific network connectivity problems, and achieve improved approximation algorithm and integrality gap results for them. We introduce an important new, highly useful and applicable, network connectivity problem - the Vital Core Connectivity Problem (VCC). Despite its many practical uses, this problem has not been previously studied. We present the first constant factor approximation algorithm for VCC, and provide an upper bound on the integrality gap of its linear programming relaxation. We also introduce a new, useful, extension of the minimum spanning tree problem, called the Extended Minimum Spanning Tree Problem (EMST), that is based on a special case of VCC; and provide both a polynomial-time algorithm and a complete linear description for it. Furthermore, we show how to generalize this new problem to handle numerous disjoint vital cores, providing the first complete linear description of, and polynomial-time algorithm for, the generalized problem. We examine the Survivable Network Design Problem (SNDP) with multiple copies of edges allowed in the solution (multi-SNDP), and present a new approximation algorithm for which the approximation guarantee is better than that of the current best known for certain cases of multi-SNDP. With our method, we also obtain improved bounds on the integrality gap of the linear programming relaxation of the problem. Furthermore, we show the application of these results to variations of SNDP. We investigate cases where the optimal values of multi-SNDP and SNDP are equal; and we present an improvement on the previously best known integrality gap bound and approximation guarantee for the special case of SNDP with metric costs and low vertex connectivity requirements, as well as for the similar special case of the Vertex Connected Survivable Network Design Problem (VC-SNDP). The quality of the results that one can obtain for a given network design problem often depends on its integer linear programming formulation, and, in particular, on its linear programming relaxation. In this connection, we investigate formulations for the Steiner Tree Problem (ST). We propose two new formulations for ST, and investigate their strength in terms of their associated integrality gaps.

[pt] Problemas de design decorrem de violações de princípios de design em um sistema de software. Tais problemas podem prejudicar a manutenção de sistemas e, logo, devem ser identificados e eliminados sempre que possível. Porém, identificar problemas de design não é trivial. Isso pois a documentação de design desses sistemas é em geral obsoleta ou inexistente. Assim, o desenvolvedor de um sistema tende a analisar o código-fonte em busca de problemas de design. Estudos sugerem anomalias de código-fonte como indicadores úteis desses problemas. Porém, outros estudos recentes mostram que uma única anomalia não é indicador suficiente. De fato, em torno de 80 por cento dos problemas de design estão associadas com múltiplas anomalias. Estas inter-relacionam-se na forma de aglomerações de anomalias. Embora as aglomerações de anomalias possam ajudar o desenvolvedor a identificar problemas de design, certas aglomerações contêm muitas anomalias. Isso então dificulta o raciocínio sobre a existência de um problema de design. Além disso, mesmo as propostas mais recentes de abordagens para a visualização de aglomerações de anomalias provêm suporte bastante limitado à identificação de problemas de design. Essa limitação é evidente quando um problema de design afeta múltiplos elementos na implementação de um sistema. Esta dissertação objetiva tratar essa limitação ao propor uma abordagem inovadora para a visualização de aglomerações de anomalias. Tal abordagem baseia-se em evidências coletadas a partir de vários experimentos propostos e conduzidos por nós. Contamos com a participação de desenvolvedores da academia e da indústria em cada experimento. Nossos resultados de estudo sugerem que vários desenvolvedores podem utilizar nossa abordagem de visualização para identificar de forma precisa problemas de design, especialmente aqueles que afetam múltiplos elementos de programa. Nossos resultados também apontam melhorias necessárias à abordagem com base na percepção dos desenvolvedores. / [en] Design problems are characterized by violations of design principles affecting a software system. Because they often hinder the software maintenance, developers should identify and eliminate design problems whenever possible. Nevertheless, identifying design problems is far from trivial. Due to outdated and scarce design documentation, developers not rarely have to analyze the source code for identifying these problems. Past studies suggest that code smells are useful hints of design problems. However, recent studies show that a single code smell might not suffice to reveal a design problem. That is, around 80 percent of design problems are realized by multiple code smells, which interrelate in the so-called smell agglomerations. Thus, developers can explore each smell agglomeration to identify a design problem in the source code. However, certain smell agglomerations are formed by several code smells, which makes it hard reasoning about the existence of a design problem. Visualization approaches have been proposed to represent smell agglomerations and guide developers in identifying design problems. However, those approaches provide a very limited support to the identification of specific design problems, especially the ones affecting multiple design elements. This dissertation aims to address this limitation by proposing a novel approach for the visualization of smell agglomerations. We rely on evidence collected from multiple empirical studies to design our approach. We evaluate our approach with developers from both academy and industry. Our results suggest that various developers could use our visualization approach to accurately identify design problems, in particular those affecting multiple program elements. Our results also point out to different ways for improving our visualization approach based on the developers perceptions.