Global ETD Search

1	Quantifying the strength of evidence in forensic fingerprints Forbes, Peter G. M. January 2014 (has links) Part I presents a model for fingerprint matching using Bayesian alignment on unlabelled point sets. An efficient Monte Carlo algorithm is developed to calculate the marginal likelihood ratio between the hypothesis that an observed fingerprint and fingermark pair originate from the same finger and the hypothesis that they originate from different fingers. The model achieves good performance on the NIST-FBI fingerprint database of 258 matched fingerprint pairs, though the computed likelihood ratios are implausibly extreme due to oversimplification in our model. Part II moves to a more theoretical study of proper scoring rules. The chapters in this section are designed to be independent of each other. Chapter 9 uses proper scoring rules to calibrate the implausible likelihood ratios computed in Part I. Chapter 10 defines the class of compatible weighted proper scoring rules. Chapter 11 derives new results for the score matching estimator, which can quickly generate point estimates for a parametric model even when the normalization constant of the distribution is intractable. It is used to find an initial value for the iterative maximization procedure in §3.3. Appendix A describes a novel algorithm to efficiently sample from the posterior of a von Mises distribution. It is used within the fingerprint model sampling procedure described in §5.6. Appendix B includes various technical results which would otherwise disrupt the flow of the main dissertation. 519.5
2	Towards an agent-based model for risk-based regulation Davies, G. J. January 2010 (has links) Risk-based regulation has grown rapidly as a component of Government decision making, and as such, the need for an established evidence-based framework for decisions about risk has become the new mantra. However, the process of brokering scientific evidence is poorly understood and there is a need to improve the transparency of this brokering process and decisions made. This thesis attempts to achieve this by using agent-based simulation to model the influence that power structures and participating personalities has on the brokering of evidence and thereby the confidence-building exercise that characterises risk-based regulation. As a prerequisite to the adoption of agent-based techniques for simulating decisions under uncertainty, this thesis provides a critical review of the influence power structure and personality have on the brokering of scientific evidence that informs risk decisions. Three case studies, each representing a different perspective on risk-based regulation are presented: nuclear waste disposal, the disposal of avian-influenza infected animal carcases and the reduction of dietary salt intake. Semi-structured interviews were conducted with an expert from each case study, and the logical sequence in which decisions were made was mapped out and used to inform the development of an agent-based simulation model. The developed agent-based model was designed to capture the character of the brokering process by transparently setting out how evidence is transmitted from the provider of evidence to the final decision maker. It comprises of two agents, a recipient and provider of evidence, and draws upon a historic knowledge base to permit the user to vary components of the interacting agents and of the decision-making procedure, demonstrating the influence that power structure and personality has on agent receptivity and the confidence attached to a number of different lines of evidence. This is a novel step forward because it goes beyond the scope of current risk management frameworks, for example, permitting the user to explore the influence that participants have in weighing and strengthening different lines of evidence and the impact this has on the final decision outcome. 332
3	製作中小企業信用評分卡 / An implementing "Small & Middle enterprises Credit Scorecard System 王明國, Wang,Ming- Kuo Unknown Date (has links) 根據經濟部中小企業處統計，中小企業融資餘額占整體企業融資餘額近20%，若以商業活動往來頻率觀點而言，目前臺灣之經濟主體架構係以中小企業為主軸，故中小企業對臺灣就業水準、物價、所得分配及經濟榮枯有決定性的影響。本研究思索如何有效將資訊不對稱的因素列入風險評估中，以有效衡量中小企業信用風險，幫助優良中小企業取得所需資金，並提供銀行建立進階法 BIS計算之參考，建立衡量信用風險之機制。本研究以國內某商業銀行之中小企業授信客戶為研究基礎，該銀行係目前台灣少數經營中小企業授信業務成功之銀行，累計至2005年授信往來戶數達20,000餘家，具足夠之研究樣本。依規模大小區分為小型企業及中型企業，本研究採用Weight of Evidence (WOE)模式來進行變數有效性篩選，透過統計分析建置信用評等及加成式評分卡，同時為了兼顧巴塞爾資本協定要求模型必須公開揭露以及計算正確之違約機率之考量，因此選定羅吉斯迴歸(Logistics Regression)作為統計演算法。經實證分析兩評分卡內容歸納如下: 小型企業信用評分卡：由於小型企業特殊之經營型態，在原始變數之篩選即不導入財務變數，在最終會顯著影響申貸企業信用危機之因素中，除「公司最近三個月查詢銀行家數」及「負責人有無配偶」倆變數外，餘8個變數是負責人（部份加計配偶）之銀行往來狀況及歷史信用記錄，其中有5個變數與現金卡及信用卡使用情況有關，足見小型企業資金需求仍透過負責人名義向銀行籌措，且以高資金成本之借款為主。中型企業信用評分卡：由於中型企業營業顯然較小型企業具規模，且以公司名義向銀行申請融資的現象亦較為普遍，但其財務報表絕對數字失真情形嚴重，故在原始變數之篩選導入財務變數趨勢。在最終會顯著影響申貸企業信用危機之因素中，除「公司最近三個月查詢銀行家數」、「負責人有無配偶」及「公司最近三個月不含逾催呆總餘額成長率」參變數外，餘10個變數是負責人（部份加計配偶）之銀行往來狀況及歷史信用記錄，其中有5個變數與現金卡及信用卡使用情況有關，可見中型企業與負責人之財務具有絕對關連性（資金互用），利用高成本資金之情況應仍普遍。信用評分卡中小企業羅吉斯迴歸 Weight of Evidence (WOE) Logistics Regression
4	Consecuencias ecológicas del enriquecimiento por materia orgánica procedente de la acuicultura y de vertidos de petróleo en ecosistemas costeros Sanz Lázaro, Carlos 11 July 2009 (has links) El objetivo de esta tesis es estudiar el efecto del enriquecimiento por materia orgánica producida por el cultivo de peces en el mar y por los vertidos de petróleo en el medio marino. Este trabajo intenta explicar las consecuencias ecológicas de los impactos generados por este tipo de contaminación, y en diseñar de test de toxicidad para evaluar la contaminación en el sur de las costas europeas. Específicamente, en relación con el impacto de la acuicultura, los estudios de recuperación durante la Apertura de peces bentónicos de reducción de piscicultura marina, el papel de la depredación en el sistema bentónico dispersión de los residuos y los vínculos horizontales y verticales con un impacto bentónico. / The aim of this thesis is to study the effect of organic matter enrichment produced by marinefinfish farming and oil spills on the marine environment. This work is focused on elucidating theecological consequences of the impact generated by this type of pollution, and on designingtoxictity tests to evaluate pollution for southern European coasts. Specifically, related with aquaculture impact, it studies benthic recovery during open sea fish farming abatement, the role of predation in the benthic system and links horizontal and vertical waste dispersion with benthic impact. benthic toxicity test Gammarus locusta Gammarus aequicauda petroleum PAH pyrene fluoranthene phenanthrene Microdeutopus gryllotalpa Corophium multisetosum weight of evidence oil intertidal estuary epidemiological approach community-level assessment Mediterranean wild fish particulate wastes organic enrichment maerl carrying capacity ecotoxicology fish farm Aquaculture succession feeding guilds trophic groups predation top-down control particulate wastes macrofauna diversity ecosystem functioning trophic complexity Ecología 574

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