Risk-Informed Requirements for Design and Assessment of Structures Under Temporary Use

The relatively high failure rates, with important consequences in many cases, suggest that the implicitly acceptable risk levels corresponding to temporary civil engineering structures and activities might exceed the bounds of normally acceptable levels associated with different societal activities. Among other reasons, this may be attributed to the lack of a rational approach for the assessment of risks associated with the different technologies supporting these activities in general, and for structures in particular. There is a need for establishing appropriate target reliability levels for structures under temporary use taking into account specific circumstances such as reduced risk exposure times. This issue is being addressed in this article. Acceptance criteria for building-structure-related risks to persons obtained in prior studies are adapted to the special circumstances of nonpermanent risk exposure. Thereby, the general principle followed is to maintain the same risk levels per time unit as for permanently occupied buildings. The adaptation is based on the statistical annual fatality rate, a life safety risk metric that allows for a consistent comparison of risks across different societal activities and technologies. It is shown that the target reliability indices taking account of the temporary use of buildings might be significantly higher than the values suggested for permanently used structures.     

Decisions,Science, and Values: Crafting Regulatory Alternatives Analysis

Emerging “prevention‐based” approaches to chemical regulation seek to minimize the use of toxic chemicals by mandating or directly incentivizing the adoption of viable safer alternative chemicals or processes. California and Maine are beginning to implement such programs, requiring manufacturers of consumer products containing certain chemicals of concern to identify and evaluate potential safer alternatives. In the European Union, the REACH program imposes similar obligations on manufacturers of certain substances of very high concern. Effective prevention‐based regulation requires regulatory alternatives analysis (RAA), a methodology for comparing and evaluating the regulated chemical or process and its alternatives across a range of relevant criteria. RAA has both public and private dimensions. To a significant degree, alternatives analysis is an aspect of product design; that is, the process by which private industry designs the goods it sells. Accordingly, an RAA method should reflect the attributes of well‐crafted product design tools used by businesses. But RAA adds health and environmental objectives to the mix of concerns taken into account by the product designer. Moreover, as part of a prevention‐based regulatory regime, it implicates important public values such as legitimacy, equity, public engagement, and accountability. Thus, an RAA should reflect both private standards and public values, and be evaluated against them. This article adopts that perspective, identifying an integrated set of design principles for RAA, and illustrating the application of those principles.     

Pre‐Going Private Ownership Around the World

Going private transactions are often highly leveraged, and give rise to potential agency conflicts among existing shareholders. But who exactly are those shareholders, and under what legal conditions are these transactions more likely to occur? We examine ownership structure prior to going private transactions in 33 countries around the world from 2002 to 2014. The data indicate strong and consistent evidence that pre‐going private ownership is characterized by higher institutional and corporate ownership. Family ownership lowers the probability of a public to private transaction. Stronger creditor rights increase the probability of going private, particularly for whole company and institutional buyouts.     

Longitudinal Relations of Parental Influences and Adolescent Career Aspirations and Actions in a Collectivist Society

Using social cognitive career theory as a framework, we examined the longitudinal effects of proximal parental contextual influences on career aspirations and actions in a collectivist context. We used a sample of 954 Indonesian high school students and measured parental career expectations, adolescent‐parent career congruence, self‐efficacy, outcome expectations, career aspirations, planning and exploration, twice, 6 months apart. The best‐fitting model was reciprocal, with the results showing that parental career expectations predicted subsequent career aspirations and planning, and aspirations and congruence with parents regarding career matters predicted future exploration. Self‐efficacy and outcome expectations were reciprocally related over time. Self‐efficacy served as an across‐time predictor of both parental contextual variables. Career exploration predicted future self‐efficacy and planning predicted later outcome expectations.     

Changing Social Work Students’ Perceptions of the Role of Government in a Policy Class

Understanding student political attitudes—feelings about government and perceptions of its role—has long been of interest to social scientists. One factor that may influence political attitudes is belief in a just world, a complex psychological construct well established in the literature. Our study explores changes in social work students’ perception of a supportive role of government and their beliefs in a just world after one policy course using a pretest and posttest design. Student perceptions changed toward a more supportive government role, but there was no significant change for belief in a just world. The study contributes to empirical evaluation of the social work education policy class in terms of the Council on Social Work Education competencies.     

Computing location depth and regression depth in higher dimensions

The location depth (Tukey 1975) of a point relative to a p-dimensional data set Z of size n is defined as the smallest number of data points in a closed halfspace with boundary through . For bivariate data, it can be computed in O(nlogn) time (Rousseeuw and Ruts 1996). In this paper we construct an exact algorithm to compute the location depth in three dimensions in O(n2logn) time. We also give an approximate algorithm to compute the location depth in p dimensions in O(mp3+mpn) time, where m is the number of p-subsets used.Recently, Rousseeuw and Hubert (1996) defined the depth of a regression fit. The depth of a hyperplane with coefficients (1,...,p) is the smallest number of residuals that need to change sign to make (1,...,p) a nonfit. For bivariate data (p=2) this depth can be computed in O(nlogn) time as well. We construct an algorithm to compute the regression depth of a plane relative to a three-dimensional data set in O(n2logn) time, and another that deals with p=4 in O(n3logn) time. For data sets with large n and/or p we propose an approximate algorithm that computes the depth of a regression fit in O(mp3+mpn+mnlogn) time. For all of these algorithms, actual implementations are made available.     

Semiparametric Efficient Estimation in the Generalized Odds-Rate Class of Regression Models for Right-Censored Time-to-Event Data

The generalized odds-rate class of regression models for time to event data is indexed by a non-negative constant and assumes thatg(S(t|Z)) = (t) + Zwhere g(s) = log(^-1(s-) for > 0, g₀(s) = log(- log s), S(t|Z) is the survival function of the time to event for an individual with qx1 covariate vector Z, is a qx1 vector of unknown regression parameters, and (t) is some arbitrary increasing function of t. When =0, this model is equivalent to the proportional hazards model and when =1, this model reduces to the proportional odds model. In the presence of right censoring, we construct estimators for and exp((t)) and show that they are consistent and asymptotically normal. In addition, we show that the estimator for is semiparametric efficient in the sense that it attains the semiparametric variance bound.     

Profiles of Housing Cost Burden in the United States

In this study, the ordered logistic regression model indicates that renters suffer a greater housing cost burden than homeowners and that the lower the income of the household, the larger the portion of income that is spent for housing. Further, the model also shows that the burden of high housing costs falls disproportionately on certain groups of American households. Compared to the reference group, two single-risk groups (Asian-American households and households with three or more children) and two dual-risk groups (female-headed households with three or more children and minority households with three or more children) tend to have a higher risk of excessive housing costs. Elderly households and three elderly-related groups (female-headed elderly households, minority elderly households, and female-headed minority elderly households), however, tend to have a lower risk of housing cost burden than other households. The housing cost burden of the reference group is comparable to the housing cost burden of each of the following groups: for single female-headed households; Black households; Hispanic households; and female-headed minority households. The policy implications of these findings are discussed in the paper.     

Dynamic Risk Management Systems: Hybrid Architecture and Offshore Platform Illustration

This paper describes and illustrates the architecture of computer-based Dynamic Risk Management Systems (DRMS) designed to assist real-time risk management decisions for complex physical systems, for example, engineered systems such as offshore platforms or medical systems such as patient treatment in Intensive Care Units. A key characteristic of the DRMSs that we describe is that they are hybrid, combining the powers of Probabilistic Risk Analysis methods and heuristic Artificial Intelligence techniques. A control module determines whether the situation corresponds to a specific rule or regulation, and is clear enough or urgent enough for an expert system to make an immediate recommendation without further analysis of the risks involved. Alternatively, if time permits and if the uncertainties justify it, a risk and decision analysis module formulates and evaluates options, including that of gathering further information. This feature is particularly critical since, most of the time, the physical system is only partially observable, i.e., the signals observed may not permit unambiguous characterization of its state. The DRMS structure is also dynamic in that, for a given time window (e.g., 1 day or 1 hour), it anticipates the physical system's state (and, when appropriate, performs a risk analysis) accounting for its evolution, its mode of operations, the predicted external loads and problems, and the possible changes in the set of available options. Therefore, we specifically address the issue of dynamic information gathering for decision-making purposes. The concepts are illustrated focusing on the risk and decision analysis modules for a particular case of real-time risk management on board offshore oil platforms, namely of two types of gas compressor leaks, one progressive and one catastrophic. We describe briefly the DRMS proof-of-concept produced at Stanford, and the prototype (ARMS) that is being constructed by Bureau Veritas (Paris) based on these concepts.     

Business Legitimacy among Business Students in the United States, Great Britain, and South Africa

This study compares attitudes toward business legitimacy in three countries. Positive attitudes toward business legitimacy exist when there is a congruence between organizational activities and societal expectations. Businesses are concerned about the extent to which negative attitudes toward business legitimacy will lead to increased government regulation. The results suggest that business students in all three countries are similar in their attitudes toward business legitimacy; however, blacks have more negative attitudes toward business legitimacy than do whites. This study resulted in the validation of a scale that can be used to measure attitudes toward business legitimacy on a cross-cultural basis. Business legitimacy is a major concern in South Africa as the predominately white business community seeks to give the emerging black majority a stake in the existing economic system. This revised version was published online in August 2006 with corrections to the Cover Date.