There is growing interest in the application of high-resolution radars in autonomous vehicles due to their affordability and high angular resolution. However, the azimuth ambiguity caused by the large physical distance between radar antennas relative to the signal wavelength is a challenge for its application. The problem of multiple extended target tracking using high-resolution radar measurements with azimuth ambiguity is considered. A novel pseudo-3D assignment (P3DA) method based on the pseudo measurement set (PMS) is proposed to resolve the azimuth ambiguity. This method can resolve mono (single) and split (duplicated) azimuth ambiguities common in extended target tracking. The Lagrangian relaxation based on a flexible search (LR-FS) algorithm is proposed to solve the P3DA-PMS problem efficiently. Simulation and experiment results show that the proposed algorithm outperforms conventional methods that do not address the azimuth ambiguity of extended target tracking. Since data association with only one data frame will lose information about target evolution and cannot change an association later based on subsequent measurements, a novel two-step multiframe assignment method is proposed to resolve split and azimuth ambiguity separately. In the first step, the split ambiguity is resolved by the PMS-to-PMS association, resulting in a merged PMS (MPMS). In the second step, the azimuth ambiguity is resolved by the Track-to-MPMS association. Numerical results show that the proposed method performs better than the P3DA-PMS-based method. The vehicles tracking with high-resolution radars need to provide information about their orientation and shape to achieve lidar-like performance. Due to self-occlusion, the L-shape model is frequently utilized to depict the structure of a typical vehicle. Since the measurement accuracy of high-resolution radars is not as high as that of lidars, radar measurement noise cannot be ignored. Moreover, as a side effect of using large wavelengths, multiple measurements may be produced per time step due to multipath effects. As a result, more outliers and inliers can be generated in high-resolution radar measurements. A novel lognormal likelihood-aided L-shape model is proposed to approximate the distribution of high-resolution radar measurements of vehicles. Numerical results evaluated on simulation data and the KITTI dataset show that the proposed algorithm achieves smaller orientation and position errors and larger generalized intersection over union (GIoU) compared to existing L-shape fitting algorithms for lidar measurements. / Dissertation / Doctor of Philosophy (PhD)

This thesis explores Hogg's interpretation of indeterminacy both throughout his career and in Justified Sinner, especially in the character Gil-Martin. Hogg seems to reject the tradition of choosing one side over another in such a dichotomy, and instead chooses to look at both extremes as equally co-present. Hogg wrote Justified Sinner within the framework of the literary Gothic tradition and used Gothic tropes to create ambiguity throughout his novel, as is the case throughout his body of works. Many of the ambiguities in Justified Sinner center on the character Gil-Martin. My interpretation of Gil-Martin's ambiguity complicates the traditional scholarship on Justified Sinner. / Master of Arts

Artists, designers and writers have long employed ambiguity as a tool in compelling their audience to deduce a personal meaning to their work. As computing becomes less of a strictly workspace, task-oriented phenomenon and more of a ubiquitous, life-space one, it is increasingly important to consider the intelligence of the user in the design of everyday computer-based things. Support of multiple user interpretation through ambiguity is an element whose appropriate inclusion in system design can compel the user to deduce a personal interpretation of the system's meaning and utility. The work in this paper explores the process by which users may come to deduce a meaning to an ambiguous work, both as individuals and collaboratively. Incorporating elements of ambiguity, we created SenSpace, an immersive physical environment that embeds the Greek myth of Narcissus within itself. The subsequent user study provided insight on the process by which naïve visitors may come to deduce their meanings of a work, both individually and collaboratively. Our results showed that there exists a trade-off between a user's level of interaction and depth of the interpretation of the multimedia environment. We also show how ambiguity can be used as a design method, by incorporating observed user expectations into the system. This paper uses experimental evidence to advocate the design of systems that support not only the system goal the designer has in mind, but also the multiple perspectives and meanings that the user often brings to the system. / Master of Science

In the education of an architect, at certain critical junctures, there is a need to withhold language. While passage to non-linguistic representation is at times vexing, the existence of memories and images delays the inevitable appropriation of architecture by language. Holding language in abeyance is necessary in order to wander openly amidst the labyrinth of architecture. This stance is not an indication of the inferiority of language to architecture but rather a question of finding appropriate limits. This act of withholding allows architecture to stand and withstand in the world. In the space of learning an architect constructs a threshold between ambiguity and precision in silence. The act of constructing a mold to cast a spatial form in plaster, or drawing the lineaments bounding impressions of space, is analogous to making a building. These kinds of actions require precise thinking and making. They carry the weight and burden of the delay of language. This very delay makes an architect and architecture possible. / Master of Architecture

This thesis aims to describe American Military Chaplains’ thoughts and concerns on secularism and religious pluralism in the Millennial generation. The goal is to analyze how a potential change in this generation affects the chaplain’s role. The method is in-depth semi-structured interviews with three chaplains from different service branches. The main finding is that they detect a substantial decrease in religiousness, which follows overall trends in society. Their experience is not that pluralism is gaining substantial ground, rather it is that a large portion of the troops are indifferent to religion. Even so, they do not experience a decrease in interest or need for their services, since counselling is an increasing part of their workload. The ambiguity of their role is mostly perceived as a challenge to balance their religious task with non-religious counselling/coaching and practical duties as an officer.

This thesis contributes to the theoretical work on decision and game theory when decision makers or players perceive ambiguity. The first article introduces a new axiomatic framework for ambiguity aversion and provides axiomatic characterizations for important preference classes that thus far had lacked characterizations. The second article introduces a new axiom called Weak Monotonicity which is shown to play a crucial role in the multiple prior model. It is shown that for many important preference classes, the assumption of monotonic preferences is a consequence of the other axioms and does not have to be assumed. The third article introduces an intuitive definition of perceived ambiguity in the multiple prior model. It is shown that the approach allows an application to games where players perceive strategic ambiguity. A very general equilibrium existence result is given. The modelling capabilities of the approach are highlighted through the analysis of examples. The fourth article applies the model from the previous article to a specific class of games with a lattice-structure. We perform comparative statics on perceived ambiguity and ambiguity attitude. We show that more optimism does not necessarily lead to higher equilibria when players have Alpha-Maxmin preferences. We present necessary and sufficient conditions on the structure of the prior sets for this comparative statics result to hold. The introductory chapter provides the basis of the four articles in this thesis. An overview of axiomatic decision theory, decision-making under ambiguity and ambiguous games is given. It introduces and discusses the most relevant results from the literature.

兩種語句處理模型曾被提出以解釋閱讀句子時語法及語意資訊的互動。句法優先模型(syntax-first models)認為詞性判斷必定先於語意分析，而制約滿足模型(constraint-satisfaction models)則認為不同的資訊在語句理解的過程中會同時被處理。本研究檢驗兩種語句處理模型能否解釋語句中的詞彙歧義解困(lexical ambiguity resolution)。 許多眼動研究曾發現詞彙歧義詞的次要語義偏向效應(subordinate bias effect)，顯示語意偏向次要語義的語境能加速激發歧義詞的次要語義並且產生語義競爭。然而，語境的語法在詞彙歧義解困中扮演的角色並不清楚。因而，不同語義分屬不同詞性的詞性歧義詞便提供我們一個媒介以檢驗詞彙歧義解困中詞性及語意限制的互動。 本研究的目的有二：(一) 檢驗詞性限制能否決定中文詞性歧義詞的語義解困；(二) 檢驗中文歧義詞語義的詞性是否會影響次要語義偏向效應。實驗一我們將四種不同類型的中文非均勢同形異義詞置於語法及語意皆為次要語義偏向的句子裡；實驗二則將四種不同類型的中文非均勢同形異義詞置於語法為次要語義偏向但語意中立的句子裡。受試者閱讀句子時的眼動表現會即時被記錄。 實驗一的結果發現：(一) 四類型歧義詞的次要語義偏向效應只反映在目標詞後區域的二次閱讀指標上；(二) 就效果量而言，NV歧義詞的次要語義偏向效應在目標詞及目標詞後兩個區域都比VN歧義詞來得大。實驗二的結果則發現：(一) VN歧義詞的次要語義偏向效應從目標詞區的首次閱讀指標就出現，並且持續至目標詞及目標詞後兩個區域的二次閱讀指標；(二) 另外三類型歧義詞的次要語義偏向效應直到所有分析區域的二次閱讀指標才反映出來；(三) NV歧義詞的次要語義偏向效應比VN歧義詞出現得更晚也更不明顯。整體而言，本研究的結果顯示詞性限制並不是影響中文詞性歧義詞語義解困的唯一因素。此結果支持制約滿足模型，並反對句法優先模型的預測。 / Two primary sentence processing models have been proposed to account for the interaction between syntactic and semantic information in reading sentences: Syntax-first models assume that syntactic-category assignment must precede semantic analysis, while constraint-satisfaction models propose that information from different sources is processed and weighed at the same time during sentence comprehension. The present study examined whether these sentence processing models, which assume different contribution of syntactic category and semantic context, can explain the resolution of lexical ambiguity in sentences. Several eye movement studies have demonstrated the subordinate bias effect (SBE) for lexical-semantic ambiguous words (i.e., NN/VV homographs), indicating that a subordinate-biased semantic context can boost the activation of the subordinate meaning of ambiguous words and causes meaning competition (Duffy, Morris, & Rayner, 1988). However, the role of syntactic context in lexical ambiguity resolution is less clear. Syntactic category ambiguous words (i.e., SCA words; VN/NV homographs), whose alternative meanings differ in syntactic category (e.g., watch in English), serve as a means of examining the interaction between syntactic category and semantic constraints during lexical ambiguity resolution. The purpose of the present study was twofold: (a) to examine whether the syntactic category constraint can determine the semantic resolution of Chinese SCA words, and (b) to investigate whether syntactic category of alternative meanings of Chinese homographs can influence the SBE during lexical ambiguity resolution. Four types of Chinese biased homographs (NN, VV, VN, and NV) were embedded into syntactically and semantically subordinate-biased sentences (Experiment 1) and into syntactically subordinate-biased but semantically neutral sentences (Experiment 2). Participants’ eye movements were recorded as they read each sentence. In Experiment 1, the results showed: (1) The SBE for the four types of homographs was significant only in the second-pass reading on the post-target words. (2) Numerically, the NV homographs revealed a larger effect size of SBE than VN homographs on both target and post-target words. In Experiment 2, the results showed: (1) The SBE for VN appeared from the first-pass reading on the target words and lasted to the second-pass reading on the target and post-target words. (2) The SBE for the other types of homographs did not occur until the second-pass reading in all analyzed regions. (3) The SBE for NV occurred much later and less obviously than that for VN. In general, our findings support the constraint-satisfaction models and reject the prediction of the syntax-first models, suggesting that the syntactic category constraint is not the only factor influencing the semantic resolution of SCA words.

Afin de rendre compte de la spécificité des comportements à risque des adolescents, les modèles neurocognitifs récents ont proposé d'envisager la compétition entre deux systèmes caractérisés par des trajectoires développementales différentes : un système socio-émotionnel et un système de contrôle cognitif. En effet, l'engagement des adolescents dans des conduites à risque pourrait s'expliquer par une hypersensibilité émotionnelle exacerbée par des contextes sociaux saillant comme la présence de pairs, auquel s'ajoute une immaturité des processus de contrôle nécessaires à la régulation de ces émotions. Toutefois, l'ensemble de ces modèles négligent l'influence du niveau d'incertitude associées aux situations de prise de risque, alors même que les travaux de psychologie du développement témoignent de capacités différentes dans les situations de prise de décision à risque et les situations de prise de décision sous ambiguïté chez les adolescents. Ces derniers semblent en effet parfaitement capables d'intégrer des informations probabilistes et les enjeux associés aux différentes options, mais présentent des difficultés à décider avantageusement dès lors que ces informations ne sont plus directement disponibles mais doivent être inférées sur la base de leur propre expérience. Ainsi, l'objectif général de ce travail de thèse consistait à examiner l'influence du niveau d'incertitude et du contexte social sur la prise de risque à l'adolescence. Après avoir démontré dans une première étude que les adultes étaient massivement aversifs face aux situations associées à un manque d'information probabiliste, nous avons examiné la trajectoire développementale fine de ce phénomène d'aversion à l'ambiguïté chez l'enfant, l'adolescent et l'adulte. Cette étude contribue à définir l'aversion à l'ambiguïté comme une stratégie intuitive apparaissant progressivement au début de l'adolescence et mais suggère une aversion à l'ambiguïté aussi marquée chez les adolescents de 14-16 ans que chez les adultes. Ensuite, notre troisième étude avait pour objectif de clarifier l'impact du niveau d'information sur l'engagement des adolescents dans la prise de risque, à travers une comparaison directe entre des situations dites informées et non informées. Nos résultats démontrent que les adolescents présentent des difficultés à ajuster leurs réponses au niveau de risque dans les situations non-informées alors que la simple disponibilité d'indices concernant le niveau de risque les conduit à des performances similaires à celles des adultes. La réunion de nos trois premières études suggère ainsi que la prise de risque exacerbée des adolescents résulte davantage d'un déficit d'apprentissage basé sur les feedbacks, plutôt que d'une tendance générale à explorer les situations risquées ambigües. Face à ce constat, la quatrième étude visait à clarifier l'impact d'une influence sociale risquée ou prudente sur l'engagement des adolescents dans la prise de risque selon le niveau d'incertitude de la situation. Cette dernière étude nous a ainsi permis de souligner l'influence positive de l'expérience des pairs sur les conduites à risque des adolescents et de mettre en exergue le rôle spécifique de l'expérience d'autrui comme une information de nature sociale susceptible de compenser leur difficulté à apprendre sur la base de leur propre expérience. / In order to account for the characteristics of risk-taking specific to adolescence, new neurocognitive models presuppose a competition between two systems with distinct developmental trajectories: an emotional system and a top-down control system. Indeed, heightened risk-taking in adolescence could result from increased emotional sensitivity in socio-emotional contexts, including the presence of peers, combined with immature control processes underlying emotional regulation. Unfortunately, these models ignore the potential impact of varying levels of uncertainty in risky situations, despite advances in developmental psychology that suggest adolescent's capacities differ between risky decision-making and decision-making under ambiguity. Although adolescents are fully competent at evaluating probabilities and entertaining outcome likelihoods, they fail to make advantageous choices when such information is not directly available but must be inferred from their own experience. Thus, the overall aim of this thesis is to examine the impact of both the information level regarding risks and of the social-emotional context on risk-taking during adolescence. After showing in a first study that adults are largely ambiguity-averse in situations in which information is missing, we investigated the exact developmental trajectory of such ambiguity aversion in children, adolescents and adults. This second study characterizes ambiguity aversion as an affective strategy that gradually develops at the beginning of adolescence, while demonstrating that adolescents display an ambiguity aversion as much as adults. Then, study 3 aimed to clarify the influence of information level on adolescents' risk-taking behaviors by directly comparing informed and uninformed situations. Results showed that adolescents exhibit a suboptimal ability to adjust risk-taking to the risk level in the non-informed condition, but are efficient in making advantageous choices when explicit information is provided. Taken together, the first three studies suggest that heightened risk-taking in adolescence does not result from an increased ambiguity tolerance but rather from a specific impairment of feedback-based learning. Given adolescents' learning impairments in ambiguous situations, study 4 aimed to specify the impact of cautious or risky social influence on risk-taking behaviors, depending on the level of uncertainty. This final study underlies the potential positive influence of peers on risky behaviors. Peers4 experiences could play a particular role by providing social information that is likely to balance the difficulties adolescents have learning from their own experience.

Knowledge management literature identifies numerous barriers that inhibit employees' knowledge seeking and knowledge contributing practices via information and communication technologies (ICTs). Presently, there is a significant gap in the literature that explains what factors promote common knowledge sharing barriers. To bridge this gap, this study examined two research questions: 1) What are the potential factors that contribute to the commonly accepted barriers to knowledge sharing?, and 2) How do these factors impact employees' use of ICTs for knowledge seeking and knowledge contributing? Literature review of 103 knowledge management articles identified three major barriers to knowledge sharing practices (lack of time, poor communication skills, and lack of trust) and three underlying factors that promoted these barriers (role conflict, role ambiguity, and locus of control). A six-stage content analysis study of the 103 knowledge articles identified 199 references to the observed contributors. To address the second research question, a causal knowledge sharing model was developed and seven hypotheses proposed. A survey consisting of 41 questions was distributed to 1,368 full-time analysts from a variety of industries, and 314 useful responses were analyzed using confirmatory factor analysis and structural equation modeling. The results confirmed that role conflict, role ambiguity, and locus of control predicted knowledge seeking and knowledge contributing behaviors via ICTs. Moreover, type of ICTs used was found to moderate the strength of these predictors.

The notion of Mode 2, as a shift from Mode 1 science-as-we-know-it, depicts science as practically relevant, socially distributed and democratic. Debates remain over the empirical substantiation of Mode 2. In particular, our understanding has been impeded by the mutually exclusive framing of Mode 1/Mode 2. Looking at how academic science is justified to diverse institutional interests – a situation associated with Mode 2 – it is asked, “What happens to Mode 1 where Mode 2 is in demand?” This study comprises two sequential phases. It combines interviews with 18 university spinout founders as micro-level Mode 2 exemplars, and macro-level policy narratives from 72 expert witnesses examined by select committees. An interpretive scheme (Greenwood and Hinings, 1988) is applied to capture the internal means-ends structure of each mode, where the end is to satisfy demand constituents, both in academia (Mode 1) and beyond (Mode 2). Results indicate Mode 1’s enduring influence even where non-academic demands are concerned, thus refuting that means and ends necessarily operate together as a stable mode. The causal ambiguity inherent in scientific advances necessitates (i) Mode 1 peer review as the only quality control regime systematically applicable ex ante, and (ii) Mode 1 means of knowledge production as essential for the health and diversity of the science base. Modifications to performance criteria are proposed to create a synergy between modes and justify public investment, especially in the absence of immediate outcomes. The study presents a framework of Mode1/Mode 2 coexistence that eases the problem with the either/or perception and renders Mode 2 more amenable to empirical research. It is crucial to note, though, that this is contingent on given vested interests. In this study, Mode 1’s fate is seen through academic scientists whose imperative is unique from those of other constituents, thereby potentially entailing further struggles and negotiation.