Understanding Community Resilience from a PRA Perspective Using Binary Decision Diagrams

Probabilistic risk assessment (PRA) is a useful tool to assess complex interconnected systems. This article leverages the capabilities of PRA tools developed for industrial and nuclear risk analysis in community resilience evaluations by modeling the food security of a community in terms of its built environment as an integrated system. To this end, we model the performance of Gilroy, CA, a moderate‐size town, with regard to disruptions in its food supply caused by a severe earthquake. The food retailers of Gilroy, along with the electrical power network, water network elements, and bridges are considered as components of a system. Fault and event trees are constructed to model the requirements for continuous food supply to community residents and are analyzed efficiently using binary decision diagrams (BDDs). The study also identifies shortcomings in approximate classical system analysis methods in assessing community resilience. Importance factors are utilized to rank the importance of various factors to the overall risk of food insecurity. Finally, the study considers the impact of various sources of uncertainties in the hazard modeling and performance of infrastructure on food security measures. The methodology can be applicable for any existing critical infrastructure system and has potential extensions to other hazards.     

Multivariate normal mean–variance mixture distribution based on Birnbaum–Saunders distribution

A multivariate normal mean–variance mixture based on a Birnbaum–Saunders (NMVMBS) distribution is introduced and several properties of this new distribution are discussed. A new robust non-Gaussian ARCH-type model is proposed in which there exists a relation between the variance of the observations, and the marginal distributions are NMVMBS. A simple EM-based maximum likelihood estimation procedure to estimate the parameters of this normal mean–variance mixture distribution is given. A simulation study and some real data are used to demonstrate the modelling strength of this new model.     

Cognitive distortions predict future gambling involvement

Disordered gambling is best conceptualized as a continuum of severity. Previous research has demonstrated the utility of studying individuals at all points of this spectrum. The sequence of the development of gambling problems and change in gambling involvement along this continuum of severity is not well understood. The present study examined the interplay between cognitive distortions and gambling involvement in a population sample recruited in Alberta, Canada. Data from 1372 participants over 4 assessment waves (5 years) were used to generate a 2-factor latent structure using gambling fallacies and gambling involvement measurements. Structural equation modelling showed that cognitive distortions more strongly predicted future gambling involvement than the reverse relationship, using the comparative fit index (CFI) and the root mean square error of approximation (RMSEA) to assess the models. In addition, cognitive distortions declined over time, whereas gambling involvement remained stable. The results of the study suggest that focusing primarily on cognitive mechanisms in public health initiatives for gambling disorders may be a more effective strategy than focusing on behavioural solutions.     

Hypothesis Tests for Neyman's Bias in Case–Control Studies

Survival bias is a long recognized problem in case–control studies, and many varieties of bias can come under this umbrella term. We focus on one of them, termed Neyman's bias or ‘prevalence–incidence bias’. It occurs in case–control studies when exposure affects both disease and disease-induced mortality, and we give a formula for the observed, biased odds ratio under such conditions. We compare our result with previous investigations into this phenomenon and consider models under which this bias may or may not be important. Finally, we propose three hypothesis tests to identify when Neyman's bias may be present in case–control studies. We apply these tests to three data sets, one of stroke mortality, another of brain tumors, and the last of atrial fibrillation, and find some evidence of Neyman's bias in the former two cases, but not the last case.     

Transitive and acyclic rationality indicators of fuzzy choice functions on base domain

In the present paper we introduce the indicators of the fuzzy transitive congruence axiom, fuzzy direct-revelation axiom and fuzzy acyclic congruence axiom. These indicators measure the degree to which a fuzzy choice function satisfies these axioms. We use the indicators of fuzzy transitive congruence axiom and fuzzy acyclic congruence axiom to calculate the minimum degree to which the direct fuzzy revealed preference relation is the transitive and acyclic respectively. We established that (i) the degree to which the fuzzy choice function is full rational is the degree to which it satisfies fuzzy transitive congruence axiom and (ii) the degree to which the fuzzy choice function is acyclic rational is the minimum degree to which it satisfies fuzzy direct-revelation axiom and its fuzzy revealed preference is acyclic. We show that a similarity relation on the set of fuzzy choice functions preserves the indicators of fuzzy transitive congruence axiom, fuzzy direct-revelation axiom, fuzzy acyclic congruence axiom and (transitive and acyclic) rationality indicators.     

Charisma as signal: An evolutionary perspective on charismatic leadership

We present an evolutionary perspective on charismatic leadership, arguing that charisma has evolved as a credible signal of a person's ability to solve a coordination challenge requiring urgent collective action from group members. We suggest that a better understanding of charisma's evolutionary and biological origins and functions can provide a broader perspective in which to situate current debates surrounding the utility and validity of charismatic leadership as a construct in the social sciences. We outline several key challenges which have shaped our followership psychology, and argue that the benefits of successful coordination in ancestral environments has led to the evolution of context-dependent psychological mechanisms which are especially attuned to cues and signals of outstanding personal leadership qualities. We elaborate on several implications of this signaling hypothesis of charismatic leadership, including opportunities for deception (dishonest signaling) and for large-scale coordination.     

Cross-Sectional and Longitudinal Associations of Categories of Physical Activities with Dimensions of Subjective Well-Being in Taiwanese Older Adults

Physical activity takes place in different social contexts such as leisure, home, and work. However, the differential associations of these distinct categories of activity with aspects of well-being have rarely been investigated. This study was designed to estimate independent associations of (a) leisure-time, (b) domestic and (c) work-related physical activities with subjective well-being in older adults. A cross-sectional survey was conducted in 2009 with 2,295 community-dwelling older adults aged 65 or older in Kaohsiung, Taiwan. Among them, 307 participants were selected for a 3-year follow-up study in 2012. The results based on cross-sectional and longitudinal analyses demonstrated that leisure-time physical activity, after multivariate adjustment, was positively associated with five dimensions of well-being, including ‘physical’, ‘psychological’, ‘independence’, ‘learning and growth’, and ‘social’ well-being. Household physical activity was positively associated only with ‘social’ well-being. Occupational physical activity was not related to any dimension of well-being. The study suggests that associations between physical activity and dimensions of subjective well-being during later life are dependent on the social context in which the activity takes place. This study indicates that physical activity taken as leisure has greatest potential to enhance the quality of life of older adults.     

Does race matter? Assessing consumer discrimination in the secondary basketball card market

Sociologists continue to observe the ways race permeates America's social institutions, the institution of sport being no exception. Although researchers have explored customer racial discrimination via examinations of the secondary sports card market, only three studies have explored the phenomenon in the context of basketball, a sporting context with a higher proportion of non-White players than the baseball and football leagues that have been the primary focus to date. We explore the unique way race matters on the hardwood by employing a methodological approach that previously has been used to study card collecting in other contexts. Data were obtained for 215 retired players and their rookie cards. Controlling for other factors, to include career performance, position, and card scarcity, the results reveal no direct effect of race on card values, but there is an interaction effect between race and Hall of Fame status that impacts card prices. The potential source and implications of this interaction are discussed as well as suggestions for future research.