1,826 research outputs found
Environmental management: analytical approximate solutions to the problem of detecting optimal random audit schemes
In the contest of environmental management, the problem of minimizing the expected cost due to random checking processes and a possible failure is here addressed. Non-homogeneous Poisson checking processes with continuous non-decreasing intensity are considered, leading to the explicit detection of the sub-optimal solution for exponential or uniform failure density functions. The dynamic of the optimal solution is then analized using the phase-diagram tool.Environmental management; audit scheme; random inspections; non-homogeneous Poisson checking process; optimal control; exponential failure density function; uniform failure density function.
What do distortion risk measures tell us on excess of loss reinsurance with reinstatements ?
In this paper we focused our attention to the study of an excess of loss reinsurance with reinstatements, a problem previously studied by Sundt [5] and, more recently, by Mata [4] and HÄurlimann [3]. As it is well-known, the evaluation of pure premiums requires the knowledge of the claim size distribution of the insurance risk: in order to face this question, different approaches have been followed in the actuarial literature. In a situation of incomplete information in which only some characteristics of the involved elements are known, it appears to be particularly interesting to set this problem in the framework of risk adjusted premiums. It is shown that if risk adjusted premiums satisfy a generalized expected value equation, then the initial premium exhibits some regularity properties as a function of the percentages of reinstatement.Excess of loss reinsurance, reinstatements, distortion risk measures, expected value equation
On Bounds for Concave Distortion Risk Measures for Sums of Risks
In this paper we consider the problem of studying the gap between bounds of risk measures for sums of non-independent random variables. Owing to the choice of the context where to set the problem, namely that of distortion risk measures, we first deduce an explicit formula for the risk measure of a discrete risk by referring to its writing as sum of layers. Then, we examine the case of sums of discrete risks with identical distribution. Upper and lower bounds for risk measures of sums of risks are presented in the case of concave distortion functions. Finally, the attention is devoted to the analysis of the gap between risk measures of upper and lower bounds, with the aim of optimizing it.Distortion risk measures, discrete risks, concave risk measure, upper and lower bounds, gap between bounds
Initial premium, aggregate claims and distortion risk measures in XL reinsurance with reinstatements
With reference to risk adjusted premium principle, in this paper we study excess of loss reinsurance with reinstatements in the case in which the aggregate claims are generated by a discrete distribution. In particular, we focus our study on conditions ensuring feasibility of the initial premium, for example with reference to the limit on the payment of each claim. Comonotonic exchangeability shows the way forward to a more general definition of the initial premium: some properties characterizing the proposed premium are presented.Excess of loss reinsurance; reinstatements; distortion risk measures; initial premium; exchangeability.
Distortion Risk Measures and Discrete Risks
In this paper we consider the problem of determining approximations for distortion risk measures of sums of non-independent random variables. First, we give an overview of the recent actuarial literature on distortion risk measures and convex bounds for sums of random variables. Then, we examine the case of discrete risks with identical distribution. Upper and lower bounds for risk measures of sums of risks are presented in the case of concave distortion functions. The result is then extended to cover the case of non necessarily discrete risks.Risk measures; dependency of risks; discrete risks with identical distribution; upper and lower bounds: concave risk measures.
Banks and climate change: "the state of the art"
At present there is a strong call for the financial sector to assume a special role in dealing with the economics of climate change, as one of the greatest challenges to face. This is also due to the several and severe impacts the climate-related natural events have on the real economy and consequently on the financial system. In this respect, it is of utmost importance that all the financial intermediaries, banks in particular, are adequately prepared to tackle such threats: banks are therefore called to address new and detrimental risks, but also to exploit business opportunities in a context of changing climate
Participation, Democratic Deficit and Good Regulation: a Case Study of Participatory Strategies in the European Regulation of GMO Products
In the European Union, the institutional reform that risk regulation system has undergone in the last decade has emphasised the need for fostering public participation and stakeholder involvement in decision making processes. Citizen scrutiny, in theory, ought to bring about better governance, and greater participation in public policy decisions is usually regarded as a symptom of a healthy democracy. By presenting evidence from two case studies in the field of bio-technology regulation, this paper aims to prove that taking participation as a tout court advantage is a mistake
Avaliação comparativa da sobrevivência e do crescimento de ostras da espécie Crassostrea gigas com o emprego de diferentes estruturas de cultivo
TCC (graduação em Agronomia) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, 2008A Crassotrea gigas é a ostra mais cultivada no mundo e no Brasil. Seu crescimento no Brasil é rápido, atingindo o tamanho comercial de 10 cm em 8 meses, a partir de sementes de 1 mm. Os métodos mais empregados de cultivo no Brasil para ostras são os espinhéis e fixos, com os animais colocados em lanternas verticais. Apesar disso, os ambientes de cultivo em Santa Catarina e no Brasil são rasos com alta quantidade de matéria total particulada e, fundos areno-lodosos ou lodosos, com alta concentração de matéria orgânica. Esse tipo de ambiente leva ao aumento da incidência de parasitas e predadores que podem causar grandes mortalidades nos cultivos e redução de crescimento. Técnicas de cultivo que permitam minimizar esses problemas e ainda, aumentar a produtividade com diminuição de custos e mão-de-obra são extremamente importantes para manter a qualidade e a quantidade de produção. Assim, este trabalho teve por objetivo avaliar o rendimento e a sobrevivência de ostras em diferentes fases de cultivo (intermediária e definitiva) ubmetidas a diferentes estruturas de cultivo (caixas flutuantes, lanternas verticais e lanternas horizontais), com e sem tratamento de manejo por lavação. As ostras apresentaram bom crescimento, de até 20 mm por mês na fase intermediária e 10 mm na fase definitiva, sempre menores nas caixas flutuantes e as mortalidades foram abaixo de 10 % para as diferentes fases e tratamentos empregues. Assim, as ostras passam de 50 mm até 100 mm em quatro meses de cultivo, com dois meses para cada fase. No caso das ostras nas lanternas verticais e horizontais, não foi observado nenhum comportamento padrão, havendo, para as diferentes fases e tratamentos, resultados hora melhores para as verticais, outros melhores para as horizontais e, da mesma forma, comportamentos variados para ostras com e sem manejo de lavação. Os parâmetros físico-químicos da água do mar não apresentaram grandes variações no período e as temperaturas, durante as duas fases experimentais, foram iguais variando de 19,5 a 22,8 oC. Assim, as variações e diferenças observadas para os diferentes parâmetros analisados nos diferentes tratamentos, foram atribuídas aos efeitos dos tratamentos e não de fatores ambientais. Além disso, nas condições do experimento, com as densidades utilizadas e o manejo de troca de estruturas e redução de densidade após dois meses, os resultados mostram que não há necessidade de lavação das estrutura e das ostras. Novas tecnologias de cultivo de ostras nas diferentes etapas, como o uso das lanternas horizontais deste trabalho, podem auxiliar a viabilizar os cultivos em áreas do Brasil onde hoje é difícil cultivar e podem ser aproveitadas como modelo para o cultivo de outras espécies de moluscos
On Optimal Layer Reinsurance Model
In this paper, we consider the class of non-proportional reinsurance contracts known as layer reinsurance model or limited stop-loss treaty. With the aim of finding an optimal layer reinsurance, we make the choice of considering an optimization criteria preserving stop-loss order: we derive some conditions of optimality by minimizing insurer risk exposure under a generic concave distortion risk measure
Liberal Democratic Institutions and the Damages of Political Corruption1
This article contributes to the debate concerning the identification of politically relevant cases of corruption in a democracy by sketching the basic traits of an original liberal theory of institutional corruption. We define this form of corruption as a deviation with respect to the role entrusted to people occupying certain institutional positions, which are crucial for the implementation of public rules, for private gain. In order to illustrate the damages that corrupt behaviour makes to liberal democratic institutions, we discuss the case of health care professionals' abuse of their right to conscientious objection to abortion services. We show that the conscience clause can be instrumentally abused to sabotage democratically established public rules and thus exert undue private influence on their implementation. In this sense, from a liberal democratic perspective, institutional corruption is problematic because it is disruptive of such fundamental liberal ideals as the impartiality of public institutions and citizens' political equality
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