In the years since the 9/11 attacks the incidence of terrorism has been on the rise. At the same time, news media coverage of major terrorist attacks has reached epic proportions, greatly expanding the number of individuals psychologically affected by terrorism. The goal of this dissertation is to better understand how individuals cope with terrorism experienced at a distance. Specifically, this investigation focuses on the impact of stress on integrative complexity (IC; a measure of cognitive processing; Suedfeld, Tetlock, & Streufert, 1992) during and shortly after a major terrorist event. Taken together, the findings from the three studies reported in this dissertation provide several insights into this process. Study 1 replicates and extends results from an earlier study of television newscasters reporting live on 9/11 (Jhangiani & Suedfeld, 2005), in the context of the 2005 London bombings and the medium of radio. In doing so, it provides the first empirical evidence outside of the research laboratory for the curvilinear relationship between stress and IC. Specifically, during the early stages of reports concerning the London bombings, a positive relationship is found between negative emotion and IC. However, once the nature and extent of the event become clearer, increases in negative emotion are related to decreases in IC (the disruptive stress hypothesis). Study 2 replicates this curvilinear relationship in the short-term reactions of two prominent political leaders to 9/11 and the 2005 London bombings. For one of these political leaders, the magnitude of his psychological reaction is moderated by the psychological distance between him and the victims of the attacks. Finally, Study 3 finds that two key personality variables, neuroticism and empathy, play important roles in determining the magnitude of the short-term psychological reactions to 9/11 of more than 250 students from Canada and the United States. This finding is particularly true for those students who were psychologically closer to the victims of the attacks. Implications, strengths and limitations of this research, and possible future directions are discussed.

Self-reported psychological distress is quite common in the Swedish elderly population. Feelings of psychological distress may have devastating consequences. The overall aim of this study was to explore associations between socioeconomic position and work complexity during midlife with psychological distress in old age. Ordered logistic regression was used to investigate the associations between, (I) socioeconomic position during midlife and psychological distress in old age, (II) work complexity during midlife and psychological distress in old age, (III) the association between socioeconomic position and psychological distress independent of work complexity, and (IV) the association between work complexity and psychological distress independent of socioeconomic position. The results show that (I) higher socioeconomic position during midlife is associated with less psychological distress in old age (II) higher work complexity during midlife is associated with less psychological distress in old age, and that (III) higher work complexity is associated to less psychological distress independent of socioeconomic position, (IV) but the association between socioeconomic position and psychological distress diminishes adjusting for work complexity. The main conclusion from this study is that individuals with high socioeconomic position benefits from both their position in society and from their working conditions while individuals of lower socioeconomic position are more likely to also suffer the drawbacks of disadvantageous working conditions in relation to late life psychological distress.

In this thesis, we cover the general topic of state complexity. In particular, we examine the bounds on the state complexity of some different representations of regular languages. As well, we consider the state complexity of the operation root(<i>L</i>). We give quick treatment of the deterministic state complexity bounds for nondeterministic finite automata and regular expressions. This includes an improvement on the worst-case lower bound for a regular expression, relative to its alphabetic length. The focus of this thesis is the study of the increase in state complexity of a regular language <i>L</i> under the operation root(<i>L</i>). This operation requires us to examine the connections between abstract algebra and formal languages. We present results, some original to this thesis, concerning the size of the largest monoid generated by two elements. Also, we give good bounds on the worst-case state complexity of root(<i>L</i>). In turn, these new results concerning root(<i>L</i>) allow us to improve previous bounds given for the state complexity of two-way deterministic finite automata.

Combinatorial auctions (CAs) are an important mechanism for allocating multiple items while allowing agents to specify preferences over bundles of items. In order to communicate these preferences, agents submit bids, which consist of one or more items and a value indicating the agent’s preference for these items. The process of determining the allocation of items is known as the winner determination problem (WDP). WDP for CAs is known to be NP-complete in the general case. We consider two distinct graph representations of a CA; the bid graph and the item graph. In a bid graph, vertices represent bids, and two vertices are adjacent if and only if the bids share items in common. In an item graph, each vertex represents a unique item, there is a vertex for each item, and any bid submitted by any agent must induce a connected subgraph of the item graph. We introduce a new definition of combinatorial auction equivalence by declaring two CAs equivalent if and only if their bid graphs are isomorphic. Parameterized complexity theory can be used to further distinguish between NP-hard problems. In order to make use of parameterized complexity theory in the investigation of a problem, we aim to find one or more parameters that describe some aspect of the problem such that if we fix these parameters, then either the problem is still hard (fixed-parameter intractable), or the problem can be solved in polynomial time (fixed-parameter tractable). We analyze WDP using bid graphs from within the formal scope of parameterized complexity theory. This approach has not previously been used to analyze WDP for CAs, although it has been used to solve set packing, which is related to WDP for CAs and is discussed in detail. We investigate a few parameterizations of WDP; some of the parameterizations are shown to be fixed-parameter intractable, while others are fixed-parameter tractable. We also analyze WDP when the graph class of a bid graph is restricted. We also discuss relationships between item graphs and bid graphs. Although both graphs can represent the same problem, there is little previous work analyzing direct relationships between them. Our discussion on these relationships begins with a result by Conitzer et al. [7], which focuses on the item graph representation and its treewidth, a property of a graph that measures how close the graph is to a tree. From a result by Gavril, if an item graph has treewidth one, then the bid graph must be chordal [16]. To apply the other direction of Gavril’s theorem, we use our new definition of CA equivalence. With this new definition, Gavril’s result shows that if a bid graph of a CA is chordal, then we can construct an item graph that has treewidth one for some equivalent CA.

Machine learning has enjoyed astounding practical success in a wide range of applications in recent years-practical success that often hurries ahead of our theoretical understanding. The standard framework for machine learning theory assumes full supervision, that is, training data consists of correctly labeled iid examples from the same task that the learned classifier is supposed to be applied to. However, many practical applications successfully make use of the sheer abundance of data that is currently produced. Such data may not be labeled or may be collected from various sources. The focus of this thesis is to provide theoretical analysis of machine learning regimes where the learner is given such (possibly large amounts) of non-perfect training data. In particular, we investigate the benefits and limitations of learning with unlabeled data in semi-supervised learning and active learning as well as benefits and limitations of learning from data that has been generated by a task that is different from the target task (domain adaptation learning). For all three settings, we propose Probabilistic Lipschitzness to model the relatedness between the labels and the underlying domain space, and we discuss our suggested notion by comparing it to other common data assumptions.

This thesis is a survey on the approximability of the asymmetric traveling salesmanproblem with triangle inequality (ATSP).In the ATSP we are given a set of cities and a function that gives the cost of travelingbetween any pair of cities. The cost function must satisfy the triangle inequality, i.e.the cost of traveling from city A to city B cannot be larger than the cost of travelingfrom A to some other city C and then to B. However, we allow the cost function tobe asymmetric, i.e. the cost of traveling from city A to city B may not equal the costof traveling from B to A. The problem is then to find the cheapest tour that visit eachcity exactly once. This problem is NP-hard, and thus we are mainly interested in approximationalgorithms. We study the repeated cycle cover heuristic by Frieze et al. We alsostudy the Held-Karp heuristic, including the recent result by Asadpour et al. that givesa new upper bound on the integrality gap. Finally we present the result ofPapadimitriou and Vempala which shows that it is NP-hard to approximate the ATSP with a ratio better than 117/116.

Bakgrund: Svenska redovisningsregler för onoterade företag genomgår förändring. På förslag ligger nya redovisningsregler för onoterade företag. Genom Årsredovisningslagens definition av ett mindre företag har 97 procent av Sveriges företag möjlighet att välja mellan K2 och K3. Marknaden efterfrågar en ökad kunskap om skillnaderna mellan regelverken. Syfte: Identifiera väsentliga skillnader mellan K2 och K3 samt undersöka vilka av dessa som har störst betydelse för företagen i sitt val av regelverk. Metod: En kvalitativ studie har genomförts, där intervjuer och remissvar har använts som datainsamling. En urvalsmetod har använts för att identifiera vilka skillnader som är tydliga mellan K2 och K3. De tydliga skillnaderna har sedan legat till grund för att undersöka om de även är väsentliga. Resultat och slutsatser: Skillnader som är väsentliga vid företagens val mellan K2 och K3 har identifierats på fem områden. Skillnaderna är väsentliga och påverkar därför företagens val mellan K2 och K3. Det eftersom de ingår i en bedömning av företagets samlade behov av komplexitet i sin externredovisning. / Background: Accounting regulations for unlisted companies in Sweden is changing. There is a draft for new accounting rules for unlisted companies. Through the definition of a small company in the Swedish Annual Accounting Act, 97 percent of Swedish companies will have the possibility to choose between K2 and K3. The market demands a better understanding of differences between the regulations. Aim: Identify significant differences between K2 and K3, in order to examine which of these differences that is the most important factors for companies in their selection of rules. Method: A qualitative study has been conducted in which interviews and responses were used as data collection. A sampling method was used to identify distinct differences between the K2 and K3. These differences have been the basis for examining the significant differences as well. Analysis and conclusion: Differences between K2 and K3 that are significant in the choice of the firm have been identified in five areas. These differences will therefore affect the firms’ choice between K2 and K3. The reason is that they are a part of an assessment of the company’s overall needs of complexity in their accounting.

This thesis seeks to understand the past and present state of engineering education and to plot a course for its future evolution. This research is limited to engineering education as it has taken place in North American universities during the last half of the 20th century. Within this context, broad trends are described. The description is supplemented with a case study of a unique and innovative engineering programme. The trends and case study form the foundation of a synthesis, and alternative vision, for higher education and engineering education. The intended audience of this thesis includes those who teach, design curriculum, or administer engineering education programmes. The description of the current state of engineering education contains analyses of the state and of the gaps within it. Both of these analyses are based almost exclusively on publicly available documentation. The present state of engineering is drawn from accreditation criteria. Critiques of the current state and suggestions for future change are drawn from reports commissioned by groups affiliated with professional engineering. The discussions identify recurring themes and patterns. Unlike the analysis of the literature, the case study merges interview evidence and personal experience with the available documentation. The synthesis and visions continue the trend away from formal sources towards experiences and beliefs. Engineering education research is in its infancy and shows few signs of maturing. There is no documented, common framing of engineering education nor have there been any efforts in this regard. Few sources address broad issues and those that do lack theoretical rigour. The visions for engineering education are simple amalgams of visions for the profession and for general higher education. The Department of Systems Design Engineering has enjoyed great past successes because of its unique vision that combines the theories of systems, complexity, and design with the discipline of engineering. Its recent decay can be traced to its faculty having collectively lost this vision. The original vision for Systems Design Engineering holds promise as a means to reinvent and reinvigorate both the engineering profession and engineering education. For this renaissance to be successful a theoretically rigorous research programme assessing the past, present, and future of engineering and engineering education must be developed.

In this thesis, we cover the general topic of state complexity. In particular, we examine the bounds on the state complexity of some different representations of regular languages. As well, we consider the state complexity of the operation root(<i>L</i>). We give quick treatment of the deterministic state complexity bounds for nondeterministic finite automata and regular expressions. This includes an improvement on the worst-case lower bound for a regular expression, relative to its alphabetic length. The focus of this thesis is the study of the increase in state complexity of a regular language <i>L</i> under the operation root(<i>L</i>). This operation requires us to examine the connections between abstract algebra and formal languages. We present results, some original to this thesis, concerning the size of the largest monoid generated by two elements. Also, we give good bounds on the worst-case state complexity of root(<i>L</i>). In turn, these new results concerning root(<i>L</i>) allow us to improve previous bounds given for the state complexity of two-way deterministic finite automata.

Combinatorial auctions (CAs) are an important mechanism for allocating multiple items while allowing agents to specify preferences over bundles of items. In order to communicate these preferences, agents submit bids, which consist of one or more items and a value indicating the agent’s preference for these items. The process of determining the allocation of items is known as the winner determination problem (WDP). WDP for CAs is known to be NP-complete in the general case. We consider two distinct graph representations of a CA; the bid graph and the item graph. In a bid graph, vertices represent bids, and two vertices are adjacent if and only if the bids share items in common. In an item graph, each vertex represents a unique item, there is a vertex for each item, and any bid submitted by any agent must induce a connected subgraph of the item graph. We introduce a new definition of combinatorial auction equivalence by declaring two CAs equivalent if and only if their bid graphs are isomorphic. Parameterized complexity theory can be used to further distinguish between NP-hard problems. In order to make use of parameterized complexity theory in the investigation of a problem, we aim to find one or more parameters that describe some aspect of the problem such that if we fix these parameters, then either the problem is still hard (fixed-parameter intractable), or the problem can be solved in polynomial time (fixed-parameter tractable). We analyze WDP using bid graphs from within the formal scope of parameterized complexity theory. This approach has not previously been used to analyze WDP for CAs, although it has been used to solve set packing, which is related to WDP for CAs and is discussed in detail. We investigate a few parameterizations of WDP; some of the parameterizations are shown to be fixed-parameter intractable, while others are fixed-parameter tractable. We also analyze WDP when the graph class of a bid graph is restricted. We also discuss relationships between item graphs and bid graphs. Although both graphs can represent the same problem, there is little previous work analyzing direct relationships between them. Our discussion on these relationships begins with a result by Conitzer et al. [7], which focuses on the item graph representation and its treewidth, a property of a graph that measures how close the graph is to a tree. From a result by Gavril, if an item graph has treewidth one, then the bid graph must be chordal [16]. To apply the other direction of Gavril’s theorem, we use our new definition of CA equivalence. With this new definition, Gavril’s result shows that if a bid graph of a CA is chordal, then we can construct an item graph that has treewidth one for some equivalent CA.