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Total Risk (total + risk)
Selected AbstractsDetermining arresters best positions in power system for lightning shielding failure protection using simulation optimization approachEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2010B. Vahidi Abstract The lightning stroke to power system structures especially overhead lines makes severe damages and results in less reliable power supply. The invention of surge arresters was a revolution in these systems for protecting the precise equipments from lightning stroke overvoltages. Nowadays, with ever decreasing prices, using arrester not only for protecting certain instruments but also for decreasing total risk of flashover in overall network, is investigated by academic and industrial pioneers in this area. In this paper, our goal is to introduce a heuristic method for determining optimum positions for placing transmission lines surge arresters (TLSAs) with acceptable approximation, to get lowest possible value of shielding failure risk of flashover in a selected set of overhead lines. Simulation optimization based on neural net (i.e. Meta Model) and genetic algorithm (optimization algorithm) is invoked to suggest best positions for placing TLSAs. A case study on Kerman 230,kV network shows good achievement of simulation optimization for finding optimum positions of TLSAs. Comparison is also made with the results of transient simulation to reveal the effectiveness of the method. Copyright © 2008 John Wiley & Sons, Ltd. [source] How Theories of Financial Intermediation and Corporate Risk-Management Influence Bank Risk-Taking BehaviorFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 5 2001Michael S. Pagano This paper examines the rationales for risk-taking and risk-management behavior from both a corporate finance and a banking perspective. After combining the theoretical insights from the corporate finance and banking literatures related to hedging and risk-taking, the paper reviews empirical tests based on these theories to determine which of these theories are best supported by the data. Managerial incentives are the most consistently supported rationale for describing how banks manage risk. In particular, moderate/high levels of equity ownership reduce bank risk while positive amounts of stock option grants increase bank risk-taking behavior. The review of empirical tests in the banking literature also suggests that financial intermediaries coordinate different aspects of risk (e.g., credit and interest rate risk) in order to maintain a certain level of total risk. The empirical results indicate hedgeable risks such as interest rate risk represent only one dimension of the risk-management problem. This implies empirical tests of the theories of corporate risk-management need to consider individual sub-components of total risk and the bank's ability to trade these risks in a competitive financial market. This finding is consistent with the reality that banks have non-zero expected financial distress costs and bank managers cannot fully diversify their bank-related personal investments. [source] Enterprise Risk Management: Theory and PracticeJOURNAL OF APPLIED CORPORATE FINANCE, Issue 4 2006Brian W. Nocco The Chief Risk Officer of Nationwide Insurance teams up with a distinguished academic to discuss the benefits and challenges associated with the design and implementation of an enterprise risk management program. The authors begin by arguing that a carefully designed ERM program,one in which all material corporate risks are viewed and managed within a single framework,can be a source of long-run competitive advantage and value through its effects at both a "macro" or company-wide level and a "micro" or business-unit level. At the macro level, ERM enables senior management to identify, measure, and limit to acceptable levels the net exposures faced by the firm. By managing such exposures mainly with the idea of cushioning downside outcomes and protecting the firm's credit rating, ERM helps maintain the firm's access to capital and other resources necessary to implement its strategy and business plan. At the micro level, ERM adds value by ensuring that all material risks are "owned," and risk-return tradeoffs carefully evaluated, by operating managers and employees throughout the firm. To this end, business unit managers at Nationwide are required to provide information about major risks associated with all new capital projects,information that can then used by senior management to evaluate the marginal impact of the projects on the firm's total risk. And to encourage operating managers to focus on the risk-return tradeoffs in their own businesses, Nationwide's periodic performance evaluations of its business units attempt to refl ect their contributions to total risk by assigning risk-adjusted levels of "imputed" capital on which project managers are expected to earn adequate returns. The second, and by far the larger, part of the article provides an extensive guide to the process and major challenges that arise when implementing ERM, along with an account of Nationwide's approach to dealing with them. Among other issues, the authors discuss how a company should assess its risk "appetite," measure how much risk it is bearing, and decide which risks to retain and which to transfer to others. Consistent with the principle of comparative advantage it uses to guide such decisions, Nationwide attempts to limit "non-core" exposures, such as interest rate and equity risk, thereby enlarging the firm's capacity to bear the "information-intensive, insurance- specific" risks at the core of its business and competencies. [source] Risk and Return Around Bond Rating Changes: New Evidence From the Spanish Stock MarketJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 5-6 2006Pilar Abad-Romero Abstract:, This study analyzes the effect of corporate bond rating changes on stock prices in the Spanish stock market. We explore their effects on excess of returns and systematic risk. Rating changes by Moody's, Standard and Poor's and FitchIBCA are analyzed. On an efficient market, these changes will only have some effect if they contain some new information or if they are associated to a redistribution of wealth between shareholders and bondholders. We use an extension of the event study dummy approach. Our results support the redistribution of wealth hypothesis in the abnormal returns behavior. We also find that changes in both directions cause a rebalancing effect in the total risk of the firm, with significant reductions on their systematic component. [source] Risk-Based Classification of Hypertension and the Role of Combination TherapyJOURNAL OF CLINICAL HYPERTENSION, Issue 2008Matthew R. Weir MD The recognition of a continuous relationship between elevated blood pressure (BP) and cardiovascular risk has influenced national and international guidelines for the classification, prevention, and management of hypertension. The most recent report (2003) of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure uses BP thresholds to define categories of normal, prehypertension, and hypertension. A new definition proposed by the Hypertension Writing Group in 2005 offers an approach to diagnosis and management based on global or total risk. Thus, even in the absence of sustained elevations in BP, patients may have a moderate to high risk of vascular events due to the presence of additional cardiovascular risk factors, disease markers, and target organ damage. The 2007 European guidelines continue to classify hypertension based on cutoffs while also placing emphasis on multivariate formulations for cardiovascular risk assessment and goals of therapy. All 3 sets of guidelines acknowledge the necessity of using ,2 antihypertensive agents to attain BP goals in many patients. [source] Hyperglycaemia and cardiovascular diseaseJOURNAL OF INTERNAL MEDICINE, Issue 2 2007M. Bartnik Abstract. Coronary artery disease and type 2 diabetes are chronic diseases of substantial and growing prevalence. Their coincidence is common, markedly enhancing mortality and morbidity. The risk for cardiovascular disease increases along a spectrum of blood glucose concentrations already apparent at levels regarded as normal. Accordingly, strategies for the early detection of glucometabolic disturbances are needed to find ways to prevent the occurrence of cardiovascular complications or to treat them already at an early stage. More specifically, abnormal glucose tolerance is almost twice as common amongst patients with a myocardial infarction as in population-based controls and a normal glucose regulation is indeed less common than abnormal glucose metabolism also amongst patients with stable coronary artery disease. Already an abnormal glucose tolerance is a strong risk factor for future cardiovascular events after an acute myocardial infarction. An oral glucose tolerance test should, therefore, be a part of the evaluation of total risk in all patients with coronary artery disease. As glucose disturbances are common and easy to detect, they may be suitable targets for novel secondary preventive efforts. [source] OPTIMAL RISK SHARING FOR LAW INVARIANT MONETARY UTILITY FUNCTIONSMATHEMATICAL FINANCE, Issue 2 2008E. Jouini We consider the problem of optimal risk sharing of some given total risk between two economic agents characterized by law-invariant monetary utility functions or equivalently, law-invariant risk measures. We first prove existence of an optimal risk sharing allocation which is in addition increasing in terms of the total risk. We next provide an explicit characterization in the case where both agents' utility functions are comonotone. The general form of the optimal contracts turns out to be given by a sum of options (stop-loss contracts, in the language of insurance) on the total risk. In order to show the robustness of this type of contracts to more general utility functions, we introduce a new notion of strict risk aversion conditionally on lower tail events, which is typically satisfied by the semi-deviation and the entropic risk measures. Then, in the context of an AV@R-agent facing an agent with strict monotone preferences and exhibiting strict risk aversion conditional on lower tail events, we prove that optimal contracts again are European options on the total risk. [source] A risk-factor model of epistatic interaction, focusing on autismAMERICAN JOURNAL OF MEDICAL GENETICS, Issue 5 2002Marshall B. Jones Abstract Research to date on the genetics of autism has not uncovered a major susceptibility locus and indications are that a number of genes, perhaps as many as 15,20, may play detectable but minor roles in the etiology of the condition. To cope with this situation, a risk-factor model based on standard epidemiologic designs is proposed. The model supposes that adding a factor to a fixed set of existing factors always increases the total risk. Thus, according to the model genetic contributions cumulate but are not necessarily additive. A threshold, hence, epistasis is required. The model is applied to several conditions in which the risk of autism is elevated, some genetic (fragile X, tuberous sclerosis) and some exogenous (rubella and thalidomide embryopathies). Male gender is discussed as a risk factor. This approach is contrasted primarily with Gillberg and Coleman's view of autism as "a syndrome or series of syndromes caused by many different separate individual diseases." The principal point of difference is whether the effects of different causes cumulate or do not cumulate. In the present approach they do, in Gillberg and Coleman's they do not. © 2002 Wiley-Liss, Inc. [source] The Role of Uncertainty in Investment: An Examination of Competing Investment Models Using Commercial Real Estate DataREAL ESTATE ECONOMICS, Issue 1 2000A. Steven Holland Neoclassical investment decision criteria suggest that only the systematic component of total risk affects the rate of investment, as channeled through the built-asset price. Alternatively, option-based investment models suggest a direct role for total uncertainty in investment decisionmaking. To sort out uncertainty's role in investment, we specify and empirically estimate a structural model of asset-market equilibrium. Commercial real estate time-series data with two distinct measures of asset price and uncertainty are used to assess the competing investment models. Empirical results generally favor predictions of the option-based model and hence suggest that irreversibility and delay are important considerations to investors. Our findings also have implications for macroeconomic policy and for forecasts of cyclical investment activity. [source] Attributable fractions for partitioning risk and evaluating disease prevention: a practical guideTHE CLINICAL RESPIRATORY JOURNAL, Issue 2008Geir E. Eide Abstract Introduction:, The attributable fraction (AF) is used for quantifying the fraction of diseased ascribable to one or more exposures. The methodology and software for its estimation has undergone a considerable development during the last decades. Objectives:, To introduce methods for: (i) apportioning excess risk to multiple exposures, groups of exposures and subpopulations; (ii) graphical description; and (iii) survival data. Results:, Adjusted, sequential and average AFs are reasonable measures obtainable with standard software. The latter two both sum up to the combined AF for a set of exposures. The average AFs are independent of the exposures' ordering. For an ordered, preventive strategy, scaled sample space cubes illustrate the effects on the risk of disease from stepwise exposure removal. Pie charts illustrate the portions of the total risk ascribed to different exposures or risk-profiles. Attributable hazard fraction, AF before time t, and AF within study incorporate time to disease and interventions. Conclusions:, The practice of crude calculations of AFs in epidemiology should be abandoned. Further development of methods for AFs with survival data and possibly linking it to causal modelling is of interest. Please cite this paper as: Eide GE. Attributable fractions for partitioning risk and evaluating disease prevention: a practical guide. The Clinical Respiratory Journal 2008; 2: 92,103. [source] | |||||||||||||