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21.
Fire Risks in Oil Refineries: Economic Analysis of Camera Monitoring   总被引:1,自引:0,他引:1  
A probabilistic method is presented to evaluate the economic value of fire monitoring by closed circuit TV camera in petroleum refineries. The proposed model is restricted to the analysis of risk reduction in an area where fires can be caused either by pump failure or by failure of valves and lines. The benefits come from reducing the time during which the fire grows undetected. Fire growth and expected values of losses are analyzed by a Markov model that includes five phases: (1) active undetected growth, (2) detection, (3) fire growth at the beginning of the firemen's intervention, (4) fire control, and (5) fire extinction. The results (e.g., the expected net present value of the investment) show that the proposed monitoring investment is attractive for an illustrative example.  相似文献   
22.
In December 1992, the Cadbury Committee published their Code of Best Practice. The recommendations, which largely reflected perceived best practice at the time, included separating the roles of CEO and chairman, having a minimum of three non-executive directors on the board and the formulation of audit committees. The Code also advocated that a more active role be taken by institutional investors in the promotion of good practice in corporate governance. This paper discusses how agency problems may be (partially) resolved by corporate governance, reviews the evidence on compliance with the Cadbury Code and examines the relationship between board structure and firm performance, looking for evidence that the Code has enhanced board performance. While there is no empirical evidence of an association between board structure and firm value, there is some evidence that compliance with the Cadbury recommendations enhances board oversight with respect to the manipulation of accounting numbers and the discipline of the top executive.  相似文献   
23.
The attack that occurred on September 11, 2001 was, in the end, the result of a failure to detect and prevent the terrorist operations that hit the United States. The U.S. government thus faces at this time the daunting tasks of first, drastically increasing its ability to obtain and interpret different types of signals of impending terrorist attacks with sufficient lead time and accuracy, and second, improving its ability to react effectively. One of the main challenges is the fusion of information, from different sources (U.S. or foreign), and of different types (electronic signals, human intelligence. etc.). Fusion thus involves two very distinct and separate issues: communications, i.e., ensuring that the different U.S. and foreign intelligence agencies communicate all relevant and accurate information in a timely fashion and, perhaps more difficult, merging the content of signals, some "sharp" and some "fuzzy," some dependent and some independent into useful information. The focus of this article is on the latter issue, and on the use of the results. In this article, I present a classic probabilistic Bayesian model sometimes used in engineering risk analysis, which can be helpful in the fusion of information because it allows computation of the posterior probability of an event given its prior probability (before the signal is observed) and the quality of the signal characterized by the probabilities of false positive and false negative. Experience suggests that the nature of these errors has been sometimes misunderstood; therefore, I discuss the validity of several possible definitions.  相似文献   
24.
Considerations on the design of a professional education of counselorsSome of the recently published articles about supervision-professionalizing are reflecting only sociological or psychological conceptions in order to describe and analyze professionality. In this article the authors discuss some of the mostly neglected points of view out of pedagogic and microsociologic professionalization-research (professional self, researching attitude). The existing requests of competence for supervisors are examined in order to test their teaching ability. Furthermore the content designs and didactic strategies for future counselor’s education are considered.  相似文献   
25.
This longitudinal study of forty‐four families explored fathers’ as compared to mothers’ specific contribution to their children's attachment representation at ages 6, 10, and 16 years. In toddlerhood, fathers’ and mothers’ play sensitivity was evaluated with a new assessment, the sensitive and challenging interactive play scale (SCIP). Fathers’ SCIP scores were predicted by fathers’ caregiving quality during the first year, were highly consistent across 4 years, and were closely linked to the fathers’ own internal working model of attachment. Qualities of attachment as assessed in the Strange Situation to both parents were antecedents for children's attachment security in the Separation Anxiety Test at age 6. Fathers’ play sensitivity and infant–mother quality of attachment predicted children's internal working model of attachment at age 10, but not vice versa. Dimensions of adolescents’ attachment representations were predicted by fathers’ play sensitivity only. The results confirmed our main assumption that fathers’ play sensitivity is a better predictor of the child's long‐term attachment representation than the early infant–father security of attachment. The ecological validity of measuring fathers’ sensitive and challenging interactive play behavior as compared to infant proximity seeking in times of distress is highlighted. Findings are discussed with respect to a wider view on attachment in that both parents shape their children's psychological security but each in his or her unique way.  相似文献   
26.
27.
Some program managers share a common belief that adding a redundant component to a system reduces the probability of failure by half. This is true only if the failures of the redundant components are independent events, which is rarely the case. For example, the redundant components may be subjected to the same external loads. There is, however, in general a decrease in the failure probability of the system. Nonetheless, the redundant element comes at a cost, even if it is less than that of developing the first one when both are based on the same design. Identical parts save the most in terms of design costs, but are subjected to common failure modes from possible design errors that limit the effectiveness of the redundancy. In the development of critical systems, managers thus need to decide if the costs of a parallel system are justified by the increase in the system's reliability. NASA, for example, has used redundant spacecraft to increase the chances of mission success, which worked well in the cases of the Viking and Voyager missions. These two successes, however, do not guarantee future ones. We present here a risk analysis framework accounting for dependencies to support the decision to launch at the same time a twin mission of identical spacecraft, given incremental costs and risk-reduction benefits of the second one. We illustrate this analytical approach with the case of the Mars Exploration Rovers launched by NASA in 2003, for which we had performed this assessment in 2001.  相似文献   
28.
Industries that deal with hazardous systems are faced with the task of managing a spectrum of risks within resource contraints. They have essentially two options that can be combined in a global risk-management strategy: insurance (loss sharing) and risk mitigation through technical and organizational measures. In this article, global risk-management strategies based on probabilistic risk analysis and its extension to include management factors are described. Some issues and solutions are illustrated through practical examples, drawn mostly from the recent research of the Industrial Engineering Risk Research Group at Stanford (the tiles of the U.S. Space Shuttle, offshore platforms, marine pipelines, and anesthesia in modern hospitals).  相似文献   
29.
Supervision — an instrument of quality development in residential youth care The author summarizes the discussion about quality development in residential youth care with reference to fees. It also aims to clarify how this discussion influences the day-to-day work off the staff in residential institutions. The article demonstrates that supervision remains an indispensable instrument of quality development even when other quality instruments are being used. Supervisory processes have to considerate that the institutions must develop and implement instruments to ensure and evaluate their work.  相似文献   
30.
In this paper register based family studies provide the motivation for studying a two-stage estimation procedure in copula models for multivariate failure time data. The asymptotic properties of the estimators in both parametric and semi-parametric models are derived, generalising the approach by Shih and Louis (Biometrics vol. 51, pp. 1384–1399, 1995b) and Glidden (Lifetime Data Analysis vol. 6, pp. 141–156, 2000). Because register based family studies often involve very large cohorts a method for analysing a sampled cohort is also derived together with the asymptotic properties of the estimators. The proposed methods are studied in simulations and the estimators are found to be highly efficient. Finally, the methods are applied to a study of mortality in twins.  相似文献   
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