Complex products are comprised of a large number of tightly integrated components, assemblies and systems resulting in extensive logical and physical interdependences between the constituent parts. Thus a change to one item of a system is highly likely to lead to a change to another item, which in turn can propagate further. The aim of this research therefore is to investigate dependency models that can be used to identify the impact and trace thepropagation of changes in different information domains, such as requirements, physical product architecture or organisation. Cont/d.

This thesis presents results of research aimed at developing an improved understanding of the behavior of column panel zones reinforced with doubler plates in seismic resistant steel moment frames. A primary goal of the research was to develop data to support the development of improved design guidelines for welding doubler plates to columns, with and without the presence of continuity plates. The research addressed several issues and questions related to welding and detailing of doubler plates. This included evaluation of the effects of welding the top and bottom of the doubler plate in addition to the vertical edges, the effects of extending the doubler plate beyond the panel zone, and the impact of welding a continuity plate to a doubler plate. These issues were investigated through detailed finite element models of a simplified representation of the panel zone region, subjected to monotonic loading. The results of the research suggest that, in general, there is little benefit in welding the top and bottom edges of a doubler plate if the vertical edges are welded, particularly in terms of overall panel zone strength and stiffness. However, the top and bottom welds provide some benefit in reducing stresses on the vertical welds. The results also suggest that extending the doubler plate above and below the panel zone has little benefit for heavy columns of shallow depth, such as the W14x398 considered in this analysis. However, extending the doubler plate did result in approximately a 10-percent increase in panel zone strength for deeper columns, such as the W40x264 considered in this analysis. Finally, the results showed that welding a continuity plate directly to a doubler plate had no adverse effects on the doubler plate in terms of increased forces or stresses. Interestingly, welding the continuity plate to the doubler plate simply changed the load path for transfer of load from the beam flange to the column web and doubler plate, but did not change the stresses in the doubler plate. Further research is needed to validate these findings for more accurate representations of the panel zone region of the column and for cyclic loading. / text

In this thesis, an adaptive transit routing (ATR) problem in a schedule based stochastic time-dependent transit network is defined and formulated as a finite horizon Markov Decision Process (MDP). The transit link travel times are assumed to be random with known probability distributions. Routing strategies are defined to be conditional on the arrival times at intermediate nodes, and the location and arrival times of other buses in the network. In other words, a traveler in the network decides to walk, wait or board a bus based on the real time information of all buses in the network. The objective is to find a strategy that minimizes the expected travel time, subject to constraints that guarantee that the destination is reached within a certain threshold. The value of the threshold was chosen to reflect the risk averse attitude of travelers and is computed based on the earliest time by which the destination can be reached with probability 1. The problem inherits the curse of dimensionality and state space reduction through pre-processing is achieved by solving variants of the time dependent shortest path problem. An interesting analogy between the state space reduction techniques and the concept of light cones is discussed. A dynamic program framework to solve the problem is developed by defining the state space, decision space and transition functions. Numerical results on a small instance of the Austin transit network are presented to investigate the extent of reduction in state space using the proposed methods. / text

Real time information about traffic conditions is becoming widely available through various media, and the focus on Advanced Traveler Information Systems (ATIS) is gaining importance rapidly. In such conditions, travelers have better knowledge about the system and adapt as the system evolves dynamically during their travel. Drivers may change routes along their travel in order to optimize their own objective of travel, which can be characterized by disutility functions. The focus of this research is to study the behavior of travelers with multiple trip objectives, when provided with real time information. A web based experiment is carried out to simulate a traffic network with information provision and different travel objectives. The decision strategies of participants are analyzed and compared to the optimal policy, along with few other possible decision rules and a general model is calibrated to describe the travelers' decision strategy. This research is a step towards calibrating equilibrium models for adaptive behavior with multiple user classes. / text

Given an undirected graph G(V,E) and a vertex subset U\subseteq V the U-space is the vector space over GF(2) spanned by the paths with end-points in U and the cycles in G(V,E). We extend Vismara's algorithm to the computation of the union of all minimum length bases of the U-space. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing

Abstract Background: The Ciclovia program (60.3 miles of streets temporarily closed to motorized vehicles and open to pedestrians) and the Ciclorutas (186.4 miles bicycle paths network) represent two policy and built environment approaches that have been implemented in Bogota, Colombia to increase access to recreational and physical activity (PA) opportunities and promote active transportation. Both programs have other potential public health outcomes such as quality of life and social capital. Both physical activity and social capital have been demonstrated to be strongly related with health. The purpose of this study was to describe and compare the participants from Ciclovia and Cicloruta and to explore how program usage relates to public health outcomes including, physical activity, social capital and equity. Methods: Analysis based on secondary data obtained from two surveys, one conducted in the Ciclovia and the other in the Ciclorutas in Bogota, Colombia. First, the general characteristics of the users of both programs were described and compared using the Pearson chi-square test. Second, a principal component analysis (PCA) was conducted to reduce the number of SC variables from the Ciclovia survey, by using a varimax (orthogonal) rotation method. A binary logistic regression adjusted model was developed to examine the relationship between frequency of participation on the Ciclovia and perceived SC levels. In addition, two adjusted multivariate logistic regression models were conducted to examine associations between meeting the PA recommendations with the characteristics of program use/participation. Results: The majority of the Ciclovia participants reported meeting the PA recommendation in leisure time (59.5%), whereas near all Cicloruta participants reported to meet the recommendations by cycling for transportation (70.5%). The safety perception was higher among Ciclovia users with 51.2% of those surveyed having reported feeling safe at the Ciclovia with respect to traffic and accidents and 42.4% with regard to crime. Results from the logistic regressions showed that participants who reported more frequent participation in the Ciclovia program were more likely to have a higher SC perception (OR=2.0, 95%CI=1.4-2.8), those who reported regular participation in the program had increased odds of meeting the PA recommendation in leisure time (OR=1.7, 95%CI=1.1-2.4), as well as those who reported to perform vigorous (OR=4.9, 95%CI=2.5-9.2) and moderate (OR=1.9, 95%CI=1.2-3.0) physical activity during the Ciclovia. For the Ciclorutas males (OR=1.94, 95%CI=1.2-3.2), regular Cicloruta users (OR=10.18, 95%CI=6.1-16.8), and Cicloruta users who reported participation in the Ciclovia over the last 12 months (OR=1.6, 95%CI=1.1-2.2), were more likely to meet the PA recommendation by cycling for transportation. Conclusions: The Ciclovia program and Cicloruta system represent two policy and environmental approaches that have the potential to equitably promote physical activity and provide a mobility alternative in complex urban settings such as the city of Bogota. Specifically the Ciclovia program also provides enhanced social environments in which the program users also feel safer.

The main target of the master thesis “GIS application for marking of cycle paths” is to investigate the opportunities of cycle tourism in Lithuania, and to mark the cycle tour route and cycle route as technical design using GIS technology. The cycle route designing principles, marking possibilities In Lithuania and abroad, also cycle rout designs and cyclists flows are analyzed while estimating the opportunities of cycling tourism. Basing on the collected data and the implemented pools,, the GIS sub-system of the cycle tour rout, and its’ development technology is described. Such information would be useful for the cyclists while planning the tour rout and during the tour, however such system would be even more useful if there would be more marked and classified cycle paths. After creating the common Lithuanian cycle paths database we could gather and propose an information on the cycle tourism possibilities to the cyclists, which could benefit further development of tourism in Lithuania. The Dzukija cycle route technical design data were used during development of GIS subsystem of cycle paths. Herefore the rout were marked by hands. The developed GIS subsystem allows wider information appliance. The work consists of 76 pages, 16 tables, 43 pictures, 5 annexes, 29 sources.

This study seeks to design algorithms that may be used to determine if a given lattice is a good approximation to a given rigid protein structure. Ideal lattice models discovered using our techniques may then be used in algorithms for protein folding and inverse protein folding. In this study we develop methods based on dynamic programming and branch and bound in an effort to identify “ideal” lattice models. To further our understanding of the concepts behind the methods we have utilized a simple cubic lattice for our analysis. The algorithms may be adapted to work on any lattice. We describe two algorithms. One for aligning the protein backbone to the lattice as a walk. This algorithm runs in polynomial time. The second algorithm for aligning a protein backbone as a path to the lattice. Both the algorithms seek to minimize the CRMS deviation of the alignment. The second problem was recently shown to be NP-Complete, hence it is highly unlikely that an efficient algorithm exists. The first algorithm gives a lower bound on the optimal solution to the second problem, and can be used in a branch and bound procedure. Further, we perform an empirical evaluation of our algorithm on proteins from the Protein Data Bank (PDB). / ix, 47 leaves ; 29 cm.

Superplastic forming (SPF) is a valuable near net shape fabrication method, used to produce very complex, contoured and monolithic structures that are often lighter, stronger and safer than the assemblies they replace. However, the widespread industrial use of Superplastic (SP) alloys is hindered by a number of issues including low production rate and limited predictive capabilities of stability during deformation and failure. Failure during SPD may result from geometrical macroscopic instabilities and/or microstructural aspects. However, the available failure criteria are either based on geometrical instabilities or microstructural features and do not account for both failure modes. The present study presents a generalized multi-scale stability criterion for SP materials, accounting for both aspects of failure under various loading conditions. A combined model accounting for cavity nucleation and plasticity controlled cavity growth along with a grain growth model and a modified microstructure based constitutive equation for SP materials is incorporated into Harts stability analysis to develop the proposed stability criterion for different loading conditions. Effects of initial grain size, initial levels of cavitation, nucleation strain, strain-rate sensitivity, and grain-growth exponent on the optimum forming curves of different SP alloys are investigated, for different loading conditions.

The super Catalan numbers T(m,n) = (2m)!(2n)!=2m!n!(m+n)! are integers which generalize the Catalan numbers. Since 1874, when Eugene Catalan discovered these numbers, many mathematicians have tried to find their combinatorial interpretation. This dissertation is dedicated to this open problem. In Chapter 1 we review known results on T (m,n) and their q-analog polynomials. In Chapter 2 we give a weighted interpretation for T(m,n) in terms of 2-Motzkin paths of length m+n2 and a reformulation of this interpretation in terms of Dyck paths. We then convert our weighted interpretation into a conventional combinatorial interpretation for m = 1,2. At the beginning of Chapter 2, we prove our weighted interpretation for T(m,n) by induction. In the final section of Chapter 2 we present a constructive combinatorial proof of this result based on rooted plane trees. In Chapter 3 we introduce two q-analog super Catalan numbers. We also define the q-Ballot number and provide its combinatorial interpretation. Using our q-Ballot number, we give an identity for one of the q-analog super Catalan numbers and use it to interpret a q-analog super Catalan number in the case m= 2. In Chapter 4 we review problems left open and discuss their difficulties. This includes the unimodality of some of the q-analog polynomials and the conventional combinatorial interpretation of the super Catalan numbers and their q-analogs for higher values of m.