Letteratura scientifica selezionata sul tema "Risk and uncertainty theory"
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Articoli di riviste sul tema "Risk and uncertainty theory"
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Khalil, Elias L. "Chaos Theory Versus Heisenberg's Uncertainty: Risk, Uncertainty and Economic Theory". American Economist 41, n. 2 (ottobre 1997): 27–40. http://dx.doi.org/10.1177/056943459704100204.
Testo completoAbstract (sommario):
The paper argues that there is a fundamental difference between the indeterminism of chaos theory and the indeterminism of quantum mechanics. The difference somewhat resembles Knight's distinction between risk and uncertainly. Theorists interested in going beyond equilibrium economics have failed to notice the difference. Therefore, they confuse between two kinds of economic change which involve indeterminism, viz., nonlinear dynamics and technological/institutional development. They also regard the evolutionary paradigm as an alternative of the equilibrium one—whereas each deals with a different phenomenon.
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Thomas, Robert, Marilyn Eichelberger e Missey Lee. "The Theory of Risk Uncertainty Reduction". Journal of System Safety 54, n. 2 (1 ottobre 2018): 11–18. http://dx.doi.org/10.56094/jss.v54i2.73.
Testo completoAbstract (sommario):
The objective of this research is to examine the character of safety programs in not only reducing risk, but also in reducing relative risk uncertainty. This paper approximates the distributions of both the probability and severity of a mishap as lognormal and examines the likely behavior of the co-distribution as the safety process is executed. This paper also shows how differential forces across the risk plane reduce both the risk itself and the relative uncertainty in the risk at the same time. With this new approach, risk now becomes a quantitative item with a known probability distribution, providing a new metric for safety program effectiveness.
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Bélyácz, Iván, e Katalin Daubner. "Uncertainity of risk and increasing risk of uncertainty in business decisions". Economy & finance 8, n. 3 (2021): 264–312. http://dx.doi.org/10.33908/ef.2021.3.2.
Testo completoAbstract (sommario):
Our paper follows the development of theory regarding the position of risk and uncertainty in economics from the publication of works by Knight (1921) and Keynes (1921) until the recent past. The starting point is presented by the relevant remarks of the thinkers of classical economics. Next, we describe the turning point related to Knight and Keynes and reveal the theoretical roots of risk taking. In the core chapter of the paper the authors make an attempt to re-interpret “animal spirits” as the intention for risk taking. A separate chapter is devoted to the relationship of rational choice and risk, and another one about the canonisation of risk in economics. In further parts of the paper, we examine the intentions to relativize the difference between risk and uncertainty, the negligence of uncertainty in the neo-classical system, the attempts to merge risk and uncertainty and the disruption of the unity of risk taking and risk bearing. Finally, the authors come to the conclusion that Knight’s and Keynes’ doctrines of risk and uncertainty have stood the test of time.
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Huang, Hong, e Yufu Ning. "Risk-Neutral Pricing Method of Options Based on Uncertainty Theory". Symmetry 13, n. 12 (1 dicembre 2021): 2285. http://dx.doi.org/10.3390/sym13122285.
Testo completoAbstract (sommario):
In order to rationally deal with the belief degree, Liu proposed uncertainty theory and refined into a branch of mathematics based on normality, self-duality, sub-additivity and product axioms. Subsequently, Liu defined the uncertainty process to describe the evolution of uncertainty phenomena over time. This paper proposes a risk-neutral option pricing method under the assumption that the stock price is driven by Liu process, which is a special kind of uncertain process with a stationary independent increment. Based on uncertainty theory, the stock price’s distribution and inverse distribution function under the risk-neutral measure are first derived. Then these two proposed functions are applied to price the European and American options, and verify the parity relationship of European call and put options.
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He, Zhiguo, Si Li, Bin Wei e Jianfeng Yu. "Uncertainty, Risk, and Incentives : Theory and Evidence". Finance and Economics Discussion Series 2013, n. 18 (febbraio 2013): 1–37. http://dx.doi.org/10.17016/feds.2013.18.
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He, Zhiguo, Si Li, Bin Wei e Jianfeng Yu. "Uncertainty, Risk, and Incentives: Theory and Evidence". Management Science 60, n. 1 (gennaio 2014): 206–26. http://dx.doi.org/10.1287/mnsc.2013.1744.
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Vercelli, Alessandro. "From Soft Uncertainty to Hard Environmental Uncertainty". Économie appliquée 48, n. 2 (1995): 251–69. http://dx.doi.org/10.3406/ecoap.1995.1565.
Testo completoAbstract (sommario):
The distinction between different modalities of uncertainty is crucial for the analysis of environmental risk associated with economic activity. The distinction here introduced between soft uncertainty and hard uncertainty is based on recent advances in probability theory and decision theory under uncertainty. Environmental risk associated with economic development often occurs under hard uncertainty and irreversibility and can be controlled only through a wise use of preventive policy instruments able to eliminate or mitigate it.
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Lio, Waichon, e Lifen Jia. "Uncertain production risk process with breakdowns and its shortage index and shortage time". Journal of Intelligent & Fuzzy Systems 39, n. 5 (19 novembre 2020): 7151–60. http://dx.doi.org/10.3233/jifs-200453.
Testo completoAbstract (sommario):
Since the practical production is not continuously available and sometimes suffers unexpected breakdowns, this paper applies uncertainty theory to introducing an uncertain production risk process with breakdowns to handle the production problem with uncertain cycle times (consisting of uncertain on-times and uncertain off-times) and uncertain production amounts. The concept of shortage index of the uncertain production risk process with breakdowns is provided and some formulas for the calculation are given. Furthermore, the shortage time of the uncertain production risk process with breakdowns is proposed and its uncertainty distribution is obtained. Finally, some numerical examples are revealed.
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Beranová, M., e D. Martinovičová. "Application of the theory of decision making under risk and uncertainty at modelling of costs". Agricultural Economics (Zemědělská ekonomika) 56, No. 5 (1 giugno 2010): 201–8. http://dx.doi.org/10.17221/88/2009-agricecon.
Testo completoAbstract (sommario):
The costs functions are mentioned mostly in the relation to the Break-even Analysis where they are presented in the linear form. But there exist several different types and forms of cost functions. Fist of all, it is necessary to distinguish between the short-run and long-run cost function that are both very important tools of the managerial decision making even if each one is used on a different level of management. Also several methods of estimation of the cost function's parameters are elaborated in the literature. But all these methods are based on the past data taken from the financial accounting while the financial accounting is not able to separate the fixed and variable costs and it is also strongly adjusted to taxation in the many companies. As a tool of the managerial decision making support, the cost functions should provide a vision to the future where many factors of risk and uncertainty influence economic results. Consequently, these random factors should be considered in the construction of cost functions, especially in the long-run. In order to quantify the influences of these risks and uncertainties, the authors submit the application of the Bayesian Theorem.
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Shao, Wei. "Economic Policy Uncertainty and Corporate Innovation Behavior". Frontiers in Sustainable Development 4, n. 8 (21 agosto 2024): 6–11. http://dx.doi.org/10.54691/va1cem84.
Testo completoAbstract (sommario):
This paper explores the impact of economic policy uncertainty on corporate innovation behavior. By integrating uncertainty theory, innovation theory, and real options theory, it constructs a comprehensive theoretical framework to explain how economic policy uncertainty affects corporate innovation decisions. Specifically, the paper posits that economic policy uncertainty influences corporate risk assessment, investment decisions, and option realization, ultimately having a profound impact on their innovation activities. This paper analyzes in detail the strategies that companies might adopt when facing economic policy uncertainty, including delaying investments, phased innovation investments, and diversified innovation investments. These strategies aim to minimize the risks brought about by policy uncertainty while maintaining the company's competitiveness and innovative capabilities in the market. Additionally, this paper proposes a series of hypotheses to further verify the specific impact of increased economic policy uncertainty on corporate innovation behavior. These hypotheses include: when economic policy uncertainty increases, companies will delay innovation investments; and in highly uncertain policy environments, companies tend to adopt diversified innovation investment strategies to spread risk. Finally, this paper provides valuable references from both corporate and governmental perspectives, helping corporate managers and policymakers formulate more effective innovation and management strategies in the context of economic policy uncertainty.
Tesi sul tema "Risk and uncertainty theory"
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Martinez-Correa, Jimmy. "Decisions under Risk, Uncertainty and Ambiguity: Theory and Experiments". Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/rmi_diss/29.
Testo completoAbstract (sommario):
I combine theory, experiments and econometrics to undertake the task of disentangling the subtleties and implications of the distinction between risk, uncertainty and ambiguity. One general conclusion is that the elements of this methodological trilogy are not equally advanced. For example, new experimental tools must be developed to adequately test the predictions of theory. My dissertation is an example of this dynamic between theoretical and applied economics.
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Walker, Kenneth C. "Rhetorics of Uncertainty: Networked Deliberations in Climate Risk". Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556604.
Testo completoAbstract (sommario):
This dissertation applies a mixed-methods model across three cases of climate risk in order to examine the rhetorical dynamics of uncertainties. I argue that a rhetorical approach to uncertainties can effectively scaffold civic agency in risk communication by translating conflicting interests and creating sites of public participation. By tracing the networks of scientists and their artifacts through cases of climate risk, I demonstrate how the performances of scientific ethos and their material-discursive technologies facilitate the personalization of risk as a form of scientific prudence, and thus a channel to feasible political action. I support these claims through a rhetorical model of translation, which hybridizes methods from discourse analysis and Actor-Network Theory (ANT) in order assemble a data-driven and corpus-based approach to rhetorical analysis. From this rhetorical perspective uncertainties expand on our notions of risk because they reveal associations between scientific inquiries, probability assessments, and the facilitation of political dialogues. In each case, the particular insight of the model reveals a range of rhetorical potentials in climate risk that can be confronted through uncertainties.
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PANK, ROULUND Rasmus. "Essays in empirical economics". Doctoral thesis, European University Institute, 2019. http://hdl.handle.net/1814/62944.
Testo completoAbstract (sommario):
Defence date: 20 May 2019Examining Board: Prof. Jerome Adda (Supervisor); Prof. Piero Gottardi,University of Essex; Prof. Rosemarie Nagel, Universitat Pompeu Fabra; Prof. Glenn W. Harrison, Georgia State University
This first chapter is co-authored with Nicolás Aragón and examines how participant and market confidence affect the outcomes in an experimental asset market where the fundamental value is known by all participants. Such a market should, in theory, clear at the expected value in each period. However, the literature has shown that bubbles often occur in these markets. We measure the confidence of each participant by asking them to forecast the one-period-ahead price as a discrete probability mass distribution. We find that confidence not only affects price-formation in markets, but is important in explaining the dynamics of bubbles. Moreover, as traders’ confidence grows, they become increasingly more optimistic, thus increasing the likelihood of price bubbles. The second chapter also deals with expectations and uncertainty, but from a different angle. It asks how increased uncertainty affects economic demand in a particular sector, using a discrete-choice demand framework. To investigate this issue I examine empirically to what extent varying uncertainty affects the consumer demand for flight traffic using us micro demand data. I find that the elasticity of uncertainty on demand is economically and statistically significant. The third chapter presents a more practical side to the issue examined in the first chapter. It describes how to elicit participants’ expectations in an economic experiment. The methodology is based on Harrison et al. (2017). The tool makes it easier for participants in economic experiments to forecast the movements of a key variable as discrete values using a discrete probability mass distribution that can be “drawn” on a virtual canvas using the mouse. The module I wrote is general enough that it can be included in other economic experiments.
1. Certainty and Decision-Making in Experimental Asset Markets 1.1. Literature Review 1.2. Hypotheses 1.3. Experimental Design 1.3.1. The asset market 1.3.2. Eliciting traders’ beliefs 1.3.3. Risk, Ambiguity and Hedging 1.4. Overview of experimental data 1.4.1. Summary of the trade data 1.4.2. Expectation data 1.5. Results 1.5.1. Predictions and forecast 1.5.2. Convergence of expectations 1.5.3. Market volatility and initial expectations 1.5.4. Explanatory power of certainty on price formation 1.6. Conclusion 2. The impact of macroeconomic uncertainty on demand: 2.1. Introduction 2.2. Literature review 2.3. A model of demand for flights 2.3.1. Demand 2.3.2. Firms 2.4. Data 2.4.1. The characteristics of the products 2.4.2. Market and macroeconomic characteristics 2.4.3. Instruments 2.4.4. Product shares 2.5. Results 2.6. Conclusion 3. forecast.js: a module for measuring expectation in economic experiments 3.1. Background 3.1.1. Elicitating Expectations in Experimental Finance 3.1.2. Eliciting a Distribution of Beliefs: Theoretical Considerations 3.2. Using the forecast.js module 3.2.1. Calibration 3.2.2. Accessing the forecast data 3.3. The generated data 3.3.1. Example of individual expectations 3.3.2. Timing Considerations 3.3.3. Prediction precision over time 3.4. Conclusion Bibliography A. Appendix to Chapter 1 A.1. Further robustness checks A.1.1. Additional graph for Hypothesis 2 A.1.2. Increased agreement with the Bhattacharyya coefficient A.1.3. Additional robustness checks for Hypothesis 3 A.2. Instructions for experiment A.2.1. General Instructions A.2.2. How to use the computerized market A.3. Questionnaire A.3.1. Before Session A.3.2. After Session B. Appendix to Chapter 3 99 B.1. Robustness check of precision B.2. Using forecast.js in a standalone HTML page B.3. Using forecast.js with oTree B.3.1. Setting up models.py B.3.2. The pages.py file B.3.3. Display forecast modules on the pages
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Li, Kehan. "Stress, uncertainty and multimodality of risk measures". Thesis, Paris 1, 2017. http://www.theses.fr/2017PA01E068.
Testo completoAbstract (sommario):
Dans cette thèse, nous discutons du stress, de l'incertitude et de la multimodalité des mesures de risque en accordant une attention particulière à deux parties. Les résultats ont une influence directe sur le calcul du capital économique et réglementaire des banques. Tout d'abord, nous fournissons une nouvelle mesure de risque - la VaR du stress du spectre (SSVaR) - pour quantifier et intégrer l'incertitude de la valeur à risque. C'est un modèle de mise en œuvre de la VaR stressée proposée par Bâle III. La SSVaR est basée sur l'intervalle de confiance de la VaR. Nous étudions la distribution asymptotique de la statistique de l'ordre, qui est un estimateur non paramétrique de la VaR, afin de construire l'intervalle de confiance. Deux intervalles de confiance sont obtenus soit par le résultat gaussien asymptotique, soit par l'approche saddlepoint. Nous les comparons avec l'intervalle de confiance en bootstrapping par des simulations, montrant que l'intervalle de confiance construit à partir de l'approche saddlepoint est robuste pour différentes tailles d'échantillons, distributions sous-jacentes et niveaux de confiance. Les applications de test de stress utilisant SSVaR sont effectuées avec des rendements historiques de l'indice boursier lors d'une crise financière, pour identifier les violations potentielles de la VaR pendant les périodes de turbulences sur les marchés financiers. Deuxièmement, nous étudions l'impact de la multimodalité des distributions sur les calculs de la VaR et de l'ES. Les distributions de probabilité unimodales ont été largement utilisées pour le calcul paramétrique de la VaR par les investisseurs, les gestionnaires de risques et les régulateurs. Cependant, les données financières peuvent être caractérisées par des distributions ayant plus d'un mode. Avec ces données nous montrons que les distributions multimodales peuvent surpasser la distribution unimodale au sens de la qualité de l'ajustement. Deux catégories de distributions multimodales sont considérées: la famille de Cobb et la famille Distortion. Nous développons un algorithme d'échantillonnage de rejet adapté, permettant de générer efficacement des échantillons aléatoires à partir de la fonction de densité de probabilité de la famille de Cobb. Pour une étude empirique, deux ensembles de données sont considérés: un ensemble de données quotidiennes concernant le risque opérationnel et un scénario de trois mois de rendement du portefeuille de marché construit avec cinq minutes de données intraday. Avec un éventail complet de niveaux de confiance, la VaR et l'ES à la fois des distributions unimodales et des distributions multimodales sont calculés. Nous analysons les résultats pour voir l'intérêt d'utiliser la distribution multimodale au lieu de la distribution unimodale en pratiqueIn this thesis, we focus on discussing the stress, uncertainty and multimodality of risk measures with special attention on two parts. The results have direct influence on the computation of bank economic and regulatory capital. First, we provide a novel risk measure - the Spectrum Stress VaR (SSVaR) - to quantify and integrate the uncertainty of the Value-at-Risk. It is an implementation model of stressed VaR proposed in Basel III. The SSVaR is based on the confidence interval of the VaR. We investigate the asymptotic distribution of the order statistic, which is a nonparametric estimator of the VaR, in order to build the confidence interval. Two confidence intervals are derived from either the asymptotic Gaussian result, or the saddlepoint approach. We compare them with the bootstrapping confidence interval by simulations, showing that the confidence interval built from the saddlepoint approach is robust for different sample sizes, underlying distributions and confidence levels. Stress testing applications using SSVaR are performed with historical stock index returns during financial crisis, for identifying potential violations of the VaR during turmoil periods on financial markets. Second, we investigate the impact of multimodality of distributions on VaR and ES calculations. Unimodal probability distributions have been widely used for parametric VaR computation by investors, risk managers and regulators. However, financial data may be characterized by distributions having more than one modes. For these data, we show that multimodal distributions may outperform unimodal distribution in the sense of goodness-of-fit. Two classes of multimodal distributions are considered: Cobb's family and Distortion family. We develop an adapted rejection sampling algorithm, permitting to generate random samples efficiently from the probability density function of Cobb's family. For empirical study, two data sets are considered: a daily data set concerning operational risk and a three month scenario of market portfolio return built with five minutes intraday data. With a complete spectrum of confidence levels, the VaR and the ES from both unimodal distributions and multimodal distributions are calculated. We analyze the results to see the interest of using multimodal distribution instead of unimodal distribution in practice
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Raykov, Radoslav S. "Essays in Applied Microeconomic Theory". Thesis, Boston College, 2012. http://hdl.handle.net/2345/bc-ir:104087.
Testo completoAbstract (sommario):
Thesis advisor: Utku UnverThis dissertation consists of three essays in microeconomic theory: two focusing on insurance theory and one on matching theory. The first chapter is concerned with catastrophe insurance. Motivated by the aftermath of hurricane Katrina, it studies a strategic model of catastrophe insurance in which consumers know that they may not get reimbursed if too many other people file claims at the same time. The model predicts that the demand for catastrophe insurance can ``bend backwards'' to zero, resulting in multiple equilibria and especially in market failure, which is always an equilibrium. This shows that a catastrophe market can fail entirely due to demand-driven reasons, a result new to the literature. The model suggests that pricing is key for the credibility of catastrophe insurers: instead of increasing demand, price cuts may backfire and instead cause a ``race to the bottom.'' However, small amounts of extra liquidity can restore the system to stable equilibrium, highlighting the importance of a functioning reinsurance market for large risks. These results remain robust both for expected utility consumer preferences and for expected utility's most popular alternative, rank-dependent expected utility. The second chapter develops a model of quality differentiation in insurance markets, focusing on two of their specific features: the fact that costs are uncertain, and the fact that firms are averse to risk. Cornerstone models of price competition predict that firms specialize in products of different quality (differentiate their products) as a way of softening price competition. However, real-world insurance markets feature very little differentiation. This chapter offers an explanation to this phenomenon by showing that cost uncertainty fundamentally alters the nature of price competition among risk-averse firms by creating a drive against differentiation. This force becomes particularly pronounced when consumers are picky about quality, and is capable of reversing standard results, leading to minimum differentiation instead. The chapter concludes with a study of how the costs of quality affect differentiation by considering two benchmark cases: when quality is costless and when quality costs are convex (quadratic). The third chapter focuses on the theory of two-sided matching. Its main topic are inefficiencies that arise when agent preferences permit indifferences. It is well-known that two-sided matching under weak preferences can result in matchings that are stable, but not Pareto efficient, which creates bad incentives for inefficiently matched agents to stay together. In this chapter I show that in one-to-one matching with weak preferences, the fraction of inefficiently matched agents decreases with market size if agents are sufficiently diverse; in particular, the proportion of agents who can Pareto improve in a randomly chosen stable matching approaches zero when the number of agents goes to infinity. This result shows that the relative degree of the inefficiency vanishes in sufficiently large markets, but this does not provide a "cure-all'' solution in absolute terms, because inefficient individuals remain even when their fraction is vanishing. Agent diversity is represented by the diversity of each person's preferences, which are assumed randomly drawn, i.i.d. from the set of all possible weak preferences. To demonstrate its main result, the chapter relies on the combinatorial properties of random weak preferences
Thesis (PhD) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Economics
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Kentel, Elçin. "Uncertainty Modeling Health Risk Assessment and Groundwater Resources Management". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11584.
Testo completoAbstract (sommario):
Real-world problems especially the ones that involve natural systems are complex and they are composed of many non-deterministic components. Uncertainties associated with these non-deterministic components may originate from randomness or from imprecision due to lack of information. Until recently, uncertainty, regardless of its nature or source has been treated by probability concepts. However, uncertainties associated with real-world systems are not limited to randomness. Imprecise, vague or incomplete information may better be represented by other mathematical tools, such as fuzzy set theory, possibility theory, belief functions, etc. New approaches which allow utilization of probability theory in combination with these new mathematical tools found applications in various engineering fields. Uncertainty modeling in human health risk assessment and groundwater resources management areas are investigated in this thesis.
In the first part of this thesis two new approaches which utilize both probability theory and fuzzy set theory concepts to treat parameter uncertainties in carcinogenic risk assessment are proposed. As a result of these approaches fuzzy health risks are generated. For the fuzzy risk to be useful for practical purposes its acceptability with respect to compliance guideline has to be evaluated. A new fuzzy measure, the risk tolerance measure, is proposed for this purpose. The risk tolerance measure is a weighed average of the possibility and the necessity measures which are currently used for decision making purposes. In the second part of this thesis two decision making frameworks are proposed to determine the best groundwater resources management strategy in the Savannah region, Georgia. Groundwater resources management problems, especially ones in the coastal areas are complex and require treatment of various uncertain inputs. The first decision making framework proposed in this study is composed of a coupled simulation-optimization model followed by a fuzzy multi-objective decision making approach while the second framework includes a groundwater flow model in which the parameters of the flow equation are characterized by fuzzy numbers and a decision making approach which utilizes the risk tolerance measure proposed in the first part of this thesis.
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Zargar, Yaghoobi Amin H. "Handling uncertainty in hydrologic analysis and drought risk assessment using Dempster-Shafer theory". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43814.
Testo completoAbstract (sommario):
The aim of this thesis is to enhance some of the hydrologic analyses involved in drought risk assessment (DRA) to uncertainty-driven analyses therefore improving the accuracy and informativeness of DRA. In DRA, risk, or the expected loss from drought hazard is estimated by integrating the magnitude of hazard (i.e., drought severity) with vulnerability (i.e., susceptibility to losses from drought). Most hydrologic analyses including DRA are traditionally performed in a deterministic setting, ignoring data quality and uncertainty issues. Uncertainty can affect the accuracy of modeling results and undermine subsequent decision making. In order to handle uncertainty in DRA, this thesis uses the Dempster-Shafer theory (DST) which provides a unified platform for modeling and propagating uncertainty in the forms of variability, conflict and incompleteness. First, DST is used to model and propagate uncertainty arisen from a high degree of conflict between two datasets of a drought hazard indicator, the snow water equivalent. Four DST combination rules are used for conflict-resolution and results unanimously indicate a high possibility of drought. Second, the Standardized Precipitation Index (SPI) is used as a generic measure of hazard and is linked directly with wildfire risk in current and future climate scenarios. Using DST, modifications are introduced into SPI, enabling the integration of uncertainty analysis with SPI processes. The resulting enhanced SPI can model the effects of long-term shifts in climate normals on drought hazard while simultaneously evaluating the significance of these shifts within the range of surrounding uncertainty. Later, vulnerability to wildfire is simulated using enhanced SPI and two additional variables: evaporation and firefighting capacity. The estimated risk indicates that forests in Okanagan Basin are vulnerable to wildfires during periods of 2040-2069 and 2070-2099 unless the firefighting capacity is enhanced with a presumed rate. Through the successful implementation of DST into DRA processes, this research demonstrates the capability of DST in improving hydrologic analyses and enhancing informativeness in the water resources arena in general.
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Niculescu, Mihai. "Towards a Unified Treatment of Risk and Uncertainty in Choice Research". University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1249493228.
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Zhao, Mingjun. "Essays on model uncertainty in macroeconomics". Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1153244452.
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Garcia, Thomas. "A behavioral approach of decision making under risk and uncertainty". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/132313/1/Thomas%20Jean-Christophe%20Lucien_Garcia_Thesis.pdf.
Testo completoAbstract (sommario):
This thesis investigates how individuals make decisions under risk and uncertainty. It is composed of four essays that theoretically and experimentally investigate decision-making. First, I study situations where individuals must decide whether an event has occurred using uncertain evidence. I highlight that individuals tend to maximize accuracy instead of maximizing expected payoffs. I find that it is partially due to the existence of a value of being right and a recency bias. Second, I study how ambiguity on the costs or the benefits of a donation affects donation behavior. I show that individuals use ambiguity strategically as an excuse to behave less generously without feeling guilty. Finally, I study the external validity of risk preference measures based on a representative panel of the Dutch population. I find that risk-preference measures are related to behavior in experimental risk tasks, however they are not related to risk-taking in the field.
Libri sul tema "Risk and uncertainty theory"
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Alghalith, Moawia. New economics of risk and uncertainty: Theory and applications. Hauppauge, N.Y: Nova Science Publishers, 2011.
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Chavas, Jean-Paul. Risk analysis in theory and practice. Amsterdam: Elsevier/Butterworth Heinemann, 2004.
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Ford, J. L. Economic choice under uncertainty: A perspective theory approach. Aldershot, Hants, England: E. Elgar, 1987.
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de, Rocquigny Etienne, Devictor Nicolas e Tarantola Stefano, a cura di. Uncertainty in industrial practice: A guide to quantitative uncertainty management. Hoboken, N.J: Wiley, 2008.
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Carlo, Jaeger, a cura di. Risk, uncertainty, and rational action. London: Earthscan, 2001.
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John, Geweke, a cura di. Decision making under risk and uncertainty: New models and empirical findings. Dordrecht: Kluwer Academic Publishers, 1992.
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Laker, Michael. Das Mehrproduktunternehmen in einer sich ändernden unsicheren Umwelt. Heidelberg: Physica, 1988.
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Prendergast, Canice. The tenuous tradeoff between risk and incentives. Cambridge, MA: National Bureau of Economic Research, 2000.
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Demers, Fanny. Price uncertainty, the competitive firm and the dual theory of choice under risk. Ottawa: Carleton University. Department of Economics, 1989.
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1955-, Hinchliffe Steve, Woodward Kath e Open University, a cura di. The natural and the social: Uncertainty, risk, change. London: Routledge in association with The Open University, 2000.
Cerca il testo completoCapitoli di libri sul tema "Risk and uncertainty theory"
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Rescher, Nicholas. "Uncertainty". In Risk Theory, 31–36. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78502-4_6.
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Rescher, Nicholas. "Uncertainty". In Risk Theory, 31–36. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78502-4_6.
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Liu, Baoding. "Uncertain Risk Analysis". In Uncertainty Theory, 115–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-13959-8_3.
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Liu, Baoding. "Uncertain Risk Analysis". In Uncertainty Theory, 137–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44354-5_6.
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Rescher, Nicholas. "Managing Risk and Uncertainty". In Risk Theory, 51–57. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78502-4_9.
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Rescher, Nicholas. "Managing Risk and Uncertainty". In Risk Theory, 51–57. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78502-4_9.
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Riesch, Hauke. "Levels of Uncertainty". In Handbook of Risk Theory, 87–110. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-1433-5_4.
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Riesch, Hauke. "Levels of Uncertainty". In Essentials of Risk Theory, 29–56. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-5455-3_2.
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Yoe, Charles. "Uncertainty." In Handbook of phytosanitary risk management: theory and practice, 39–54. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781780648798.0039.
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Levy, Haim. "Expected Utility Theory". In Studies in Risk and Uncertainty, 21–39. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4757-2840-8_2.
Testo completoAtti di convegni sul tema "Risk and uncertainty theory"
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Hu, Junming, Fayuan Wei, Renwei Ge e Tianxi Liang. "Propagation of parameter uncertainty based on evidence theory". In 2011 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (ICQR2MSE). IEEE, 2011. http://dx.doi.org/10.1109/icqr2mse.2011.5976753.
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Zhou, Jiao, Xingyu Peng e Dongchi Yao. "Quantitative Risk Assessment Techniques Based on Uncertainty Theory for Natural Gas Distribution Station". In 2018 12th International Pipeline Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipc2018-78260.
Testo completoAbstract (sommario):
Pipeline stations, as an important part of long-distance pipeline systems, include lots of facilities which are highly concentrated and always operate continuously. Risk assessment is an important foundation work for the risk management of these stations. Since various uncertainties exist during the quantitative risk assessment (QRA), this paper explores the theories and approaches of QRA for station accidents, and also introduces some specific mathematical theories for quantification and dealing with uncertainties. This paper combines uncertainty theory effectively with the QRA for gas distribution stations, analyzes the uncertain factors in the QRA of gas distribution station, and establishes Bayesian update model for estimating basic events’ failure rates and probabilities of failure on demand based on generic failure data and plant-specific data. And it also offers conversion method among conjugate prior distribution of different types. Besides, probabilistic estimation model is set up by the combination of fuzzy set theory, expert judgments and fuzzy group decision making. The paper builds Fuzzy Bow-Tie quantitative model for distribution station under dependency relationships, and proposes the sensitivity analysis method for the accident model based on fuzzy importance index, fuzzy uncertainty index and minimal cut sets importance index.
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Auer, E., e W. Luther. "Dempster-Shafer Theory Based Uncertainty Models for Assessing Hereditary, BRCA1/2-Related Cancer Risk". In 8th International Symposium on Reliability Engineering and Risk Management. Singapore: Research Publishing Services, 2022. http://dx.doi.org/10.3850/978-981-18-5184-1_gs-03-079-cd.
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Hu, Huan, Xiaoshi Du, Chen Xu, Feng Zhao, Xiangning Lin e Zhiqian Bo. "Risk assessment of cascading failure in power systems based on uncertainty theory". In 2011 IEEE Power & Energy Society General Meeting. IEEE, 2011. http://dx.doi.org/10.1109/pes.2011.6039029.
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Lapcevic, Zoran, e Svetislav Soskic. "DECISION SUPPORT IN EMERGENCY SITUATIONS BASED ON RISK ASSESSMENT". In SECURITY AND CRISIS MANAGEMENT - THEORY AND PRACTICE. RASEC, 2024. https://doi.org/10.70995/jjld6005.
Testo completoAbstract (sommario):
One of the fundamental characteristics of modern society is the increasing number of situations where security is compromised. Special significance is given to situations caused by human, natural, or technical-technological actions, collectively referred to as "emergency situations." They are termed "emergencies" due to their sudden, unexpected, and asymmetric negative consequences for people, property, and the environment. The primary characteristic of emergency situations is uncertainty. Uncertainty arises from the lack of sufficient human knowledge about certain phenomena and the genesis of their occurrence. As a result, there is an inability to accurately predict such occurrences or plan protective measures against these dangers. The extent to which certain characteristics of dangers are understood allows humans to act preventively, i.e., to prepare for action in case of danger escalation. The quality of both preventive and curative measures depends on the quality of the decision-making process regarding the type, location, timing, and forces needed for response. Most of the necessary information is obtained by assessing the risks of specific dangers occurring and determining their potential consequences.
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Huisheng Gao, Jing Zhu e Congcong Li. "The analysis of uncertainty of network security risk assessment using Dempster-Shafer theory". In in Design (CSCWD). IEEE, 2008. http://dx.doi.org/10.1109/cscwd.2008.4537073.
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Williams, David T., e Jery R. Stedinger. "Practical Applications of Risk and Uncertainty Theory in Water Resources: Shortcuts Taken and Their Possible Effects". In World Environmental and Water Resources Congress 2011. Reston, VA: American Society of Civil Engineers, 2011. http://dx.doi.org/10.1061/41173(414)388.
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Dongli, Jia, Diao Yinglong, Wang Cunping e Huang Renle. "Research on Fault Risk Ranking and Screening of Distribution Network Based on Uncertainty Theory". In 2018 China International Conference on Electricity Distribution (CICED). IEEE, 2018. http://dx.doi.org/10.1109/ciced.2018.8592488.
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Ashkinadze, Konstantin. "Method of Critical Stochastic Inputs for Extreme Uncertainty Problems: Theory and Applications". In Second International Conference on Vulnerability and Risk Analysis and Management (ICVRAM) and the Sixth International Symposium on Uncertainty, Modeling, and Analysis (ISUMA). Reston, VA: American Society of Civil Engineers, 2014. http://dx.doi.org/10.1061/9780784413609.253.
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Yang, J., J. Wu, L. Wang e B. Wu. "Design and uncertainty analysis of ice cream bar turning mechanism based on axiom design and TRIZ theory". In 12th International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering (QR2MSE 2022). Institution of Engineering and Technology, 2022. http://dx.doi.org/10.1049/icp.2022.2873.
Testo completoRapporti di organizzazioni sul tema "Risk and uncertainty theory"
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Zio, Enrico, e Nicola Pedroni. Literature review of methods for representing uncertainty. Fondation pour une culture de sécurité industrielle, dicembre 2013. http://dx.doi.org/10.57071/124ure.
Testo completoAbstract (sommario):
This document provides a critical review of different frameworks for uncertainty analysis, in a risk analysis context: classical probabilistic analysis, imprecise probability (interval analysis), probability bound analysis, evidence theory, and possibility theory. The driver of the critical analysis is the decision-making process and the need to feed it with representative information derived from the risk assessment, to robustly support the decision. Technical details of the different frameworks are exposed only to the extent necessary to analyze and judge how these contribute to the communication of risk and the representation of the associated uncertainties to decision-makers, in the typical settings of high-consequence risk analysis of complex systems with limited knowledge on their behaviour.
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Lempert, Robert J., Michelle Miro e Diogo Prosdocimi. A DMDU Guidebook for Transportation Planning Under a Changing Climate. A cura di Benoit Lefevre e Ernesto Monter Flores. Inter-American Development Bank, febbraio 2021. http://dx.doi.org/10.18235/0003042.
Testo completoAbstract (sommario):
The effects of climate-related natural hazards pose a significant threat to sustainable development in Latin America and the Caribbean (LAC) region and in particular its transportation sector. Risk Management provides an appropriate framework for assessing and mitigating the impacts of climate change and other climate-related natural hazards on transportation systems and choosing actions to enhance their resilience. However, analysts and policymakers involved in transportation planning, policy, and investment face significant challenges in managing the risks triggered by the effects of climate change. Climate change impacts the lifespan of roads, airports, and railroads as they have time horizons that surpass 40 years, thus making it harder (if not impossible) to forecast with confidence all relevant future events that will affect such infrastructure. In addition, the climate has already changed, so the return frequency of storms, for example, and other extreme events may now be different than suggested by the historical record in ways that are not always currently well understood. Implementing Risk Management under conditions of such uncertainty can prove difficult. Decision Making Under Deep Uncertainty (DMDU) enables Risk Management under conditions of Deep Uncertainty, that is when risks cannot confidently be quantified. This guidebook is aligned with the Disaster and Climate Change Risk Assessment Methodology for IDB projects (IDB 2018) and introduces and provides guidance on applying methods for Decision Making Under Deep Uncertainty (DMDU) to transportation planning. It presents the methodological steps that are necessary for the implementation of DMDU methodologies and reviews several such methods, including scenario planning, Adaptive Pathways, and robust decision making (RDM). This review is geared towards supporting the incorporation of DMDU methods into IDBs transportation sector funding and planning processes.
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Darling, Arthur H., Diego J. Rodríguez e William J. Vaughan. Uncertainty in the Economic Appraisal of Water Quality Improvement Investments: The Case for Project Risk Analysis. Inter-American Development Bank, luglio 2000. http://dx.doi.org/10.18235/0008825.
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This technical paper argues that Monte Carlo risk analysis offers a more comprehensive and informative way to look at project risk ex-ante than the traditional (and often arbitrary), one-influence-at-atime sensitivity analysis approach customarily used in IDB analyses of economic feasibility. The case for probabilistic risk analysis is made using data from a project for cleaning up the Tietê river in São Paulo, Brazil. A number of ways to handle uncertainty about benefits are proposed, and their implications for the project acceptance decision and the consequent degree of presumed project risk are explained and illustrated.
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Zio, Enrico, e Nicola Pedroni. Overview of risk-informed decision-making processes. Fondation pour une culture de sécurité industrielle, ottobre 2012. http://dx.doi.org/10.57071/539rdm.
Testo completoAbstract (sommario):
The authors introduce the general concepts, definitions and issues related to the use of Risk-informed decision-making (RIDM). These are structured processes which assist decision-makers when faced with high impact, complex decisions involving multiple objectives and the presence of uncertainty. They aim to ensure that decisions between competing alternatives are taken with an awareness of the risks associated with each option, and that all attributes of a decision are considered in an integrated manner. Motivations for the use of these techniques as a complement to more traditional deterministic approaches to risk assessment are provided. The RIDM processes adopted by NASA and by the US Nuclear Regulatory Commission are described in detail, with an analysis of commonalities and differences in approach.
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Lazo, Jeffrey. Communicating Forecast Uncertainty (CoFU) 2: Replication and Extension of a Survey of the US Public's Sources, Perceptions, Uses, and Values for Weather Information. American Meteorological Society, settembre 2024. http://dx.doi.org/10.1175/cofu2-2024.
Testo completoAbstract (sommario):
Understanding end-users’ sources, perceptions, uses, and values of weather information is critical to the Weather Enterprise’s efforts to deliver the most accurate, most timely, and most relevant weather information to all 330 Million Americans. In 2006, a survey of the general public of the United States explored a range of issues related to the communication, use, understanding, and value of weather forecasts. In 2022, this survey was reimplemented, revisting questions related to the sources, perceptions, uses, and value of weather information. To the maximum extent possible the exact same survey instrument, implementation methods, and target population were replicated. Five additional topics were included at the end of the instrument to begin to assess these related concepts (cultural risk theory, numeracy, perceived vulnerability, political preferences, and risk preferences). This report presents an initial analysis of some aspects of the 2022 survey.
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Agarwala, Matthew, Matt Burke, Jennifer Doherty-Bigara, Patrycja Klusak e Kamiar Mohaddes. Climate Change and Sovereign Risk: A Regional Analysis for the Caribbean. Inter-American Development Bank, aprile 2024. http://dx.doi.org/10.18235/0012885.
Testo completoAbstract (sommario):
Climate change is an existential threat to the world economy, with complex, evolving and nonlinear dynamics that remain a source of great uncertainty. There is a bourgeoning literature on the economic impact of climate change, but research on how climate change affects sovereign risks is limited. This paper provides forward-looking regional analysis of the effects of climate change on sovereign creditworthiness, probability of default and the cost of borrowing for the Caribbean economies. Our results indicate that there is substantial variation in the sensitivity of ratings to climate change across the region which is due to the non-linear nature of ratings. Our findings improve the identification and management of sovereign climate risk and provides a forward-looking assessment of how climate change could affect the cost of accessing international finance. As such, it leads to a suite of policy options for countries in the region.
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Mangalathu, Sujith, Mehrdad Shokrabadi e Henry Burton. Aftershock Seismic Vulnerability and Time-Dependent Risk Assessment of Bridges. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, maggio 2019. http://dx.doi.org/10.55461/uuue2614.
Testo completoAbstract (sommario):
The time-dependent seismic risk of bridges is assessed while account accounting for the effect of aftershocks and the uncertainty in the damage state after a mainshock event. To achieve this, a Markov risk-assessment framework is adopted to account for the probabilistic transition of the bridge structure through different damage states and time-dependent aftershock hazard. The methodology is applied to three typical California bridge configurations that differ only based on their era of design and construction. Era 11, Era 22, and Era 33 designations are used for the three bridges, which are designed and detailed to reflect pre-1971, 1971–1990 and post-1990 construction. In addition to mainshock-only evaluations (used as a benchmark to quantify the additional risk posed by aftershocks), pre-mainshock (to account for the uncertainty in the occurrence of mainshock and aftershock events) and post-mainshock (which are based on a conditioning mainshock event and bridge damage state) seismic risk assessments are performed. To support these assessments, a set of 34 pairs of ground motions from as-recorded mainshock–aftershock sequences is assembled. Sequential nonlinear response history analyses (including incremental dynamic analyses) are used to obtain the response demands when the structural models of all bridges are subjected to mainshock-only records or mainshock–aftershock record-pairs. Physical damage in both the mainshock and mainshock–aftershock environments is defined using the following mutually exclusive and collectively exhaustive limit states: Intact, Slight, Moderate, Extensive, and Complete. For both the pre- and post-mainshock assessments, the additional risk caused by aftershock hazard is found to be higher for the older bridges (i.e., Era 11 and Era 22) and more severe conditioning damage states. A direct correlation between the bridge’s age and the increase in seismic risk due to aftershock hazard was also observed for the pre-mainshock assessment. It is suggested that the proposed methodology be used to make informed decisions regarding the appropriateness and timing of bridge closures (partial and complete) following a seismic event while considering aftershock hazard.
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Gherman, Iulia, Victoria Cohen, Daniel Lloyd, Wioleta Trzaska, Niall Grieve, Johanna Jackson, Elaine Pegg e Anthony Wilson. Risk of campylobacteriosis from low-throughput poultry slaughterhouses. Food Standards Agency, luglio 2023. http://dx.doi.org/10.46756/sci.fsa.xkw971.
Testo completoAbstract (sommario):
Campylobacter is the most common cause of bacterial foodborne illness in the UK. Every year there are an estimated 300,000 foodborne cases in the UK, of which more than half are related to poultry meat. Campylobacter naturally lives in the guts of poultry. Undercooked chicken meat is the main source of exposure to Campylobacter. Thorough cooking kills Campylobacter. Cross-contamination of other food or work surfaces during preparation or storage of chicken can also cause illness. Campylobacter levels are routinely monitored in chicken carcases that are processed in high-throughput slaughterhouses, but this testing is not currently carried out in some low-throughput slaughterhouses. Each high-throughput slaughterhouse processes more than 7.5 million birds per year and each low-throughput slaughterhouse processes less than 7.5 million birds per year. Of the 1 billion birds that are slaughtered annually in the UK, around 5% come from low-throughout slaughterhouses. This report estimates the difference in risk of campylobacteriosis for products from low-throughput and high-throughput poultry slaughterhouses in the UK. This was necessary work to assist the FSA in establishing an appropriate level of sampling for low-throughput slaughterhouses. We considered the whole pathway of the chicken from farm to fork using the scientific literature, data from our own survey of Campylobacter in slaughterhouses (FS9990010), and business data and information on UK levels of infection. Campylobacter levels over a 3-month period (September to December 2021) from chicken processed by low and high-throughput slaughterhouses were the main data used for our comparison. We could find no data on differences in the supply of birds to low- versus high-throughput abattoirs, and no data on differences in the use of the meat after leaving the slaughterhouses. Based on analysis of the limited survey data available, we could not detect a significant difference between the proportion of highly contaminated samples from low- and high-throughput slaughterhouses. We also could not detect a significant difference in Campylobacter levels in slaughterhouses that perform religious slaughter versus those that do not. Based on the number of chickens per year that are processed by low and high-throughput slaughterhouses, we estimated the number of Campylobacter cases in the UK annually that are likely linked to low- and high-throughput slaughterhouses respectively. Based on the evidence available, we conclude that the frequency of occurrence of campylobacteriosis in the total UK population from chicken produced in low-throughput slaughterhouses is medium and for high-throughput slaughterhouses is high, with a medium uncertainty, as a direct consequence of the relative volume of chicken produced by each type of plant. The severity of campylobacteriosis is low, with low uncertainty. This assumes that the proportion of the total domestic consumption of chicken meat originating from low-throughput slaughterhouses does not change. The current sampling regime requires samples to be taken once a week. If more than 15 out of 50 of samples have high levels of Campylobacter, this is considered a failure and mitigations need to be put in place. We predicted that if samples are taken once every two weeks or once every four weeks instead, that would still allow us to identify some slaughterhouses failing to comply with the 15/50 exceedance rate. However, identifying issues will take longer and may not detect some failing slaughterhouses. Sampling requirements are not consistently applied in low-throughput slaughterhouses, and we did not have access to data on the steps taken when slaughterhouses recorded high levels of Campylobacter. Therefore, it was not possible to state the effect of changes in sampling requirements on per-portion risk. However, due to the small proportion of total poultry meat consumed in the UK that is produced at low-throughput slaughterhouses, changes to the official sampling requirements at low-throughput slaughterhouses are unlikely to result in a large difference in the frequency of occurrence of campylobacteriosis in the UK population.
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Desjardins. L52204 Framework for the Optimization of Inspection Intervals. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), dicembre 2004. http://dx.doi.org/10.55274/r0011352.
Testo completoAbstract (sommario):
The goal of this project is to develop a methodology to find the optimal inspection timing of pipelines carrying hazardous materials. The four principle parameters affecting the need for inspection are: - Anomaly severity - Deterioration rate Limit state - Consequences of failure In addition to these parameters, considered in this research, uncertainty needs to be understood and accounted for. Knowledge of each of the above parameters is limited by various factors. Morrison has chosen to approach this uncertainty with a probabilistic method that leads to a risk and reliability solution. As applicable to the optimization of inspection timing, the goal of this report is to provide a set of procedures to: - Assess pipeline integrity - Assess corrosion rates Predict future corrosion severity - Predict the increase of probability of failure (POF), reliability, and risk as a function of time and location along the pipeline - Optimize inspection, repair, and mitigation programs to maintain target integrity levels There is software related to this research.
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Maycock, Barry, Cath Mulholland, Emma French e Joseph Shavila. Rapid Risk Assessment: What is the risk from microcystins in the edible flesh of fish caught from Lough Neagh? Food Standards Agency, marzo 2024. http://dx.doi.org/10.46756/sci.fsa.slz868.
Testo completoAbstract (sommario):
During the Summer and Autumn of 2023, Lough Neagh in Northern Ireland was affected by a cyanobacterial bloom. Testing of water from within the bloom reported high concentrations of one type of cyanobacterial toxin, microcystins. Samples were taken from the Lough of eels, roach, perch, pollan and bream and tested for a range of cyanobacterial toxins, including microcystins, nodularins, anatoxin, cylindrospermopsin and saxitoxin. Each sample comprised 10 fish, and five samples were taken of each species, except for bream for which a single sample was collected. The fish were dissected and the edible flesh, intestine, liver, roe, gonad and/or gills analysed separately. Microcystins were detected at a range of concentrations in the various parts of the fish that were sampled - intestine, liver, roe and/or gills, but were not detected in the edible flesh of any of the fish samples. Averaged across the samples, the highest concentrations of microcystins were quantified in the intestine samples, followed by the liver samples, with low concentrations were detected in the gills and a small number of the samples of gonads and roe. None of the other toxins were detected in any fish sample. The initial analysis for microcystins was of free toxins only. However, there is evidence that microcystins which are covalently bound to proteins are also bioavailable and therefore 22 fish tissue samples, including nine fish flesh samples, were also sent to another laboratory where they were analysed by a method which measures the total concentrations of microcystins, free and protein-bound. The viscera tissue samples chosen for the further analysis were those with the highest concentrations of the free toxins, while the fish flesh samples included 2-3 samples each of eels, roach, pollan and perch. The concentrations of total microcystins found in viscera samples were around one order of magnitude higher than the concentrations of free microcystins that had been measured. However, microcystins were still not detected in the edible fish flesh samples. It is possible that microcystins were not present at any level in any of the fish flesh samples. However, the presence of microcystins in the edible flesh of fish has been reported in the scientific literature, albeit at lower levels than those in the gastrointestinal tract or other parts of the viscera such as liver (Testai et al., 2016). Since microcystins were detected in other parts of the fish sampled from Lough Neagh it is also possible that they were also present in the fish flesh but at levels below the limits of detection of the analytical methods. The limit of detection of the analytical method for total (free + bound) microcystins was 10 µg/kg wet weight. An upper bound dietary exposure assessment was conducted. While a lower bound exposure assessment would assume the microcystins were not present in the edible flesh, i.e. a concentration of 0 µg/kg, the upper bound approach assumed they were present at the limit of detection of 10 µg/kg. The true concentrations may be between these levels. The exposure assessments consider high consumers of fish (97.5th percentile). For eels, consumption data were used from the National Diet and Nutrition Survey (NDNS). For roach, perch, pollan and bream. No consumption data were available from the NDNS and consumption data for trout were used instead as a proxy. The main target organ for toxicity of the microcystins is the liver, though other organs may also be affected. The microcystin most studied toxicologically is microcystin-LR, which is one of the most common microcystins. A WHO review established a provisional tolerable daily intake (TDI) for microcystin-LR of 0.04 µg per kg bodyweight (bw). WHO recommended that exposures to total microcystins should be compared to this provisional TDI, though there is uncertainty with this as individual microcystins are likely to differ significantly in their toxic potencies. Estimated dietary exposures of total microcystins were all within the provisional TDI, indicating no health concern from consuming the edible flesh of these species. Since fish may be caught and prepared for consumption not only by food business operators but by recreational anglers, concern has been raised that evisceration may be incomplete or the edible flesh may become contaminated in the process, and therefore this was also considered in the risk assessment. This was based on the sample of fish which contained the highest concentration of total microcystins in a viscera component, which was a sample of roach with a particularly high concentration of microcystins in intestine. It was assumed that 10% of the relative proportion of intestine to flesh in the fish would be inadvertently consumed with the flesh. In this scenario, dietary exposures would be within the provisional TDI in most age groups or would marginally exceed the TDI, but this would not be toxicologically significant. In addition, since this exposure scenario used an upper bound approach to the concentration in flesh, and used the highest concentration in any viscera sample, it is not clear that there would be any exceedance of the provisional TDI in practice. Overall, it appears unlikely that consumers will substantially exceed the provisional TDI on a long-term basis due to incomplete evisceration of fish. Overall, exposure to microcystins from eating the edible flesh of the tested fish species would not be expected to cause adverse effects in consumers, including if the fish is inadequately eviscerated. Therefore, we consider the frequency of adverse reactions in the general population to be negligible, so rare that it does not merit to be included. Based on the possible levels of exposure to microcystins from fish from Lough Neagh, it is considered that any liver injury, were it to occur in consumers of fish, would result from long term exposure and be mild. Overall, we consider the severity of illness that could potentially occur as a result of exposure to microcystins from consuming edible fish flesh from Lough Neagh to be medium (i.e. moderate illness, incapacitating but not usually life-threatening and of moderate duration). We consider the level of uncertainty to be medium (i.e. there are some but no complete data available), but that this does not affect the conclusion of the risk assessment since many of the key uncertainties are addressed within the risk assessment. However, future monitoring would be useful to assess whether microcystin concentrations in the fish change over time.