Agent‐Based Recovery Model for Seismic Resilience Evaluation of Electrified Communities

In this article, an agent‐based framework to quantify the seismic resilience of an electric power supply system (EPSS) and the community it serves is presented. Within the framework, the loss and restoration of the EPSS power generation and delivery capacity and of the power demand from the served community are used to assess the electric power deficit during the damage absorption and recovery processes. Damage to the components of the EPSS and of the community‐built environment is evaluated using the seismic fragility functions. The restoration of the community electric power demand is evaluated using the seismic recovery functions. However, the postearthquake EPSS recovery process is modeled using an agent‐based model with two agents, the EPSS Operator and the Community Administrator. The resilience of the EPSS–community system is quantified using direct, EPSS‐related, societal, and community‐related indicators. Parametric studies are carried out to quantify the influence of different seismic hazard scenarios, agent characteristics, and power dispatch strategies on the EPSS–community seismic resilience. The use of the agent‐based modeling framework enabled a rational formulation of the postearthquake recovery phase and highlighted the interaction between the EPSS and the community in the recovery process not quantified in resilience models developed to date. Furthermore, it shows that the resilience of different community sectors can be enhanced by different power dispatch strategies. The proposed agent‐based EPSS–community system resilience quantification framework can be used to develop better community and infrastructure system risk governance policies.     

Shy but Getting By? An Examination of the Complex Links Among Shyness,Coping, and Socioemotional Functioning in Childhood

The purpose of the current study was to test a conceptual model of the mediated and moderated associations among shyness, coping strategies, and socioemotional functioning in middle childhood. Participants were 358 children (177 boys) aged 9–13 years (M = 10.16 years, SD =.95). Children completed self‐report assessments of shyness, coping style in response to a social stressor, internalizing problems, and peer difficulties. Among the results, shyness was positively associated with internalizing symptoms and negatively related to perceptions of peer difficulties. However, both of these associations were partially mediated by internalizing coping styles. Moreover, problem‐solving coping moderated these mediated pathways: among children who reported higher levels of problem‐solving coping, the associations between internalizing coping and outcomes were attenuated. Several gender differences also emerged, suggesting that problem‐solving coping may be particularly useful for shy boys. Results are discussed in terms of the complex but potentially critical role of coping in shy children's socioemotional functioning.     

An Optimization‐Based Framework for the Identification of Vulnerabilities in Electric Power Grids Exposed to Natural Hazards

This article proposes a novel mathematical optimization framework for the identification of the vulnerabilities of electric power infrastructure systems (which is a paramount example of critical infrastructure) due to natural hazards. In this framework, the potential impacts of a specific natural hazard on an infrastructure are first evaluated in terms of failure and recovery probabilities of system components. Then, these are fed into a bi‐level attacker–defender interdiction model to determine the critical components whose failures lead to the largest system functionality loss. The proposed framework bridges the gap between the difficulties of accurately predicting the hazard information in classical probability‐based analyses and the over conservatism of the pure attacker–defender interdiction models. Mathematically, the proposed model configures a bi‐level max‐min mixed integer linear programming (MILP) that is challenging to solve. For its solution, the problem is casted into an equivalent one‐level MILP that can be solved by efficient global solvers. The approach is applied to a case study concerning the vulnerability identification of the georeferenced RTS24 test system under simulated wind storms. The numerical results demonstrate the effectiveness of the proposed framework for identifying critical locations under multiple hazard events and, thus, for providing a useful tool to help decisionmakers in making more‐informed prehazard preparation decisions.     

Mobile phones in Africa: how much do we really know?

Mobile phones are a crucial mode of communication and welfare enhancement in poor countries, especially those lacking an infrastructure of fixed lines. In recent years much has been written about how mobile telephony in Africa is rapidly reducing the digital divide with developed countries. Yet, when one examines the evidence it is not at all clear what is really happening. In one country, Tanzania, for example, some observers point to the fact that 97% of the population lives under the mobile footprint, while others show that ownership is very limited. These extreme values prompted us to review the situation in Africa as a whole, in an effort to discover what is really going on.     

Component Criticality in Failure Cascade Processes of Network Systems

In this work, specific indicators are used to characterize the criticality of components in a network system with respect to their contribution to failure cascade processes. A realistic‐size network is considered as reference case study. Three different models of cascading failures are analyzed, differing both on the failure load distribution logic and on the cascade triggering event. The criticality indicators are compared to classical measures of topological centrality to identify the one most characteristic of the cascade processes considered.     

A General Framework for the Assessment of Power System Vulnerability to Malicious Attacks

The protection and safe operations of power systems heavily rely on the identification of the causes of damage and service disruption. This article presents a general framework for the assessment of power system vulnerability to malicious attacks. The concept of susceptibility to an attack is employed to quantitatively evaluate the degree of exposure of the system and its components to intentional offensive actions. A scenario with two agents having opposing objectives is proposed, i.e., a defender having multiple alternatives of protection strategies for system elements, and an attacker having multiple alternatives of attack strategies against different combinations of system elements. The defender aims to minimize the system susceptibility to the attack, subject to budget constraints; on the other hand, the attacker aims to maximize the susceptibility. The problem is defined as a zero‐sum game between the defender and the attacker. The assumption that the interests of the attacker and the defender are opposite makes it irrelevant whether or not the defender shows the strategy he/she will use. Thus, the approaches “leader–follower game” or “simultaneous game” do not provide differences as far as the results are concerned. The results show an example of such a situation, and the von Neumann theorem is applied to find the (mixed) equilibrium strategies of the attacker and of the defender.     

Who is the victim anyway? The effects of bystander victim impact statements on mock juror sentencing decisions

Victim impact evidence was varied in a brief trial scenario given to 120 participants eligible for jury service. The scenario concerned the murder trial of a disgruntled employee accused of bombing his former workplace. Participants read either no victim impact evidence or one of three victim impact statements. For the victim impact statements, we varied the identity of the witness. The victim impact statement was given by either the wife of the victim, a coworker of the victim, or a firefighter called to the crime scene. Results revealed that only the victim impact evidence given by the coworker lead to harsher sentencing judgments. However, participants rated the suffering of the victim's wife as most severe, indicating that perceptions of suffering may not predict sentencing judgments in a straightforward manner. Implications for these findings for legal decisions such as Payne v. Tennessee (1991) are discussed.