A proactive and resilient seismic risk mitigation strategy for existing school buildings

Different methods and procedures have been developed to define prioritisation strategies of retrofit interventions aimed at reducing the seismic risk of school buildings on a large territorial scale. However, these approaches fail to demonstrate how risk analysis has been used successfully to quantitatively assess and select the optimal risk management decision. This article proposes innovative and useful metrics to measure the potential costs and benefits related to the prioritisation of retrofit intervention and the resilience of the analysed school system by directly integrating engineering, organisational, socio-economic and political aspects in the realm of seismic resilience assessment. Based on probabilistic risk assessments considering the new vulnerability of the prioritised school buildings, these measures could predict the expected economic and functional losses associated with a disastrous seismic event, as well as the possible post-disaster recovery of the system. In order to help decision-makers in selecting the optimal mitigation strategy with a multidisciplinary and multidimensional perspective, different political scenarios, the relative prioritisations of interventions and their intervention options are also defined. The proposed framework is demonstrated in a complex case study of 1,825 public schools in the Lima metropolitan area, Peru. Policymakers, planners and engineering professionals could benefit from results.     

Cooperation in the evolutionary iterated prisoner’s dilemma game with risk attitude adaptation

The Iterated Prisoner’s Dilemma (IPD) game has been commonly used to investigate the cooperation among competitors. However, most previous studies on the IPD focused solely on maximizing players’ average payoffs without considering their risk preferences. By introducing the concept of income stream risk into the IPD game, this paper presents a novel evolutionary IPD model with agents seeking to balance between average payoffs and risks with respect to their own risk attitudes. We build a new IPD model of multiple agents, in which agents interact with one another in the pair-wise IPD game while adapting their risk attitudes according to their received payoffs. Agents become more risk averse after their payoffs exceed their aspirations, or become more risk seeking after their payoffs fall short of their aspirations. The aspiration levels of agents are determined based on their historical self-payoff information or the payoff information of the agent population. Simulations are conducted to investigate the emergence of cooperation under these two comparison methods. Results indicate that agents can sustain a highly cooperative equilibrium when they consider only their own historical payoffs as aspirations (called historical comparison) in adjusting their risk attitudes. This holds true even for the IPD with a short game encounter, for which cooperation was previously demonstrated difficult. However, when agents evaluate their payoffs in comparison with the population average payoff (called social comparison), those agents with payoffs below the population average tend to be dissatisfied with the game outcomes. This dissatisfaction will induce more risk-seeking behavior of agents in the IPD game, which will constitute a strong deterrent to the emergence of mutual cooperation in the population.     

A network analysis of official Twitter accounts during the West Virginia water crisis

Online networks using Web 2.0 technologies have proven useful for communication among all parties involved in managing crises. These networks rapidly disseminate information allowing for coordination among organizations responding to the needs of those whose safety and wellbeing are threatened by the crisis and its aftermath. This study provides a network analysis of official Twitter accounts activated during the Charleston, West Virginia, water contamination crisis in 2014. The city’s water supply was rendered unfit for drinking or bathing after 7500 gallons of a toxic chemical leaked into the Elk River. The network created by the 41 Twitter accounts associated with the West Virginia water contamination lacked density, contained several isolates, exchanged information quickly (geodesic distance diameter), and contained both national and local accounts. The lack of density indicates limited exchange of information, particularly between national and federal accounts. The rapid dissemination of the information that was shared and the fact that some accounts did bridge the local and national gap, however, show the positive potential for such networks in responding to crises.     

Do time‐averaged,whole‐building,effective volatile organic compound (VOC) emissions depend on the air exchange rate? A statistical analysis of trends for 46 VOCs in U.S. offices

We used existing data to develop distributions of time‐averaged air exchange rates (AER), whole‐building ‘effective’ emission rates of volatile organic compounds (VOC), and other variables for use in Monte Carlo analyses of U.S. offices. With these, we explored whether long‐term VOC emission rates were related to the AER over the sector, as has been observed in the short term for some VOCs in single buildings. We fit and compared two statistical models to the data. In the independent emissions model (IEM), emissions were unaffected by other variables, while in the dependent emissions model (DEM), emissions responded to the AER via coupling through a conceptual boundary layer between the air and a lumped emission source. For 20 of 46 VOCs, the DEM was preferable to the IEM and emission rates, though variable, were higher in buildings with higher AERs. Most oxygenated VOCs and some alkanes were well fit by the DEM, while nearly all aromatics and halocarbons were independent. Trends by vapor pressure suggested multiple mechanisms could be involved. The factors of temperature, relative humidity, and building age were almost never associated with effective emission rates. Our findings suggest that effective emissions in real commercial buildings will be difficult to predict from deterministic experiments or models.     

Guidelines and recommendations for indoor use of fuel cells and hydrogen systems

Hydrogen energy applications often require that systems are used indoors (e.g., industrial trucks for materials handling in a warehouse facility, fuel cells located in a room, or hydrogen stored and distributed from a gas cabinet). It may also be necessary or desirable to locate some hydrogen system components/equipment inside indoor or outdoor enclosures for security or safety reasons, to isolate them from the end-user and the public, or from weather conditions.Using of hydrogen in confined environments requires detailed assessments of hazards and associated risks, including potential risk prevention and mitigation features. The release of hydrogen can potentially lead to the accumulation of hydrogen and the formation of a flammable hydrogen-air mixture, or can result in jet-fires. Within Hyindoor European Project, carried out for the EU Fuel Cells and Hydrogen Joint Undertaking safety design guidelines and engineering tools have been developed to prevent and mitigate hazardous consequences of hydrogen release in confined environments. Three main areas are considered: Hydrogen release conditions and accumulation, vented deflagrations, jet fires and including under-ventilated flame regimes (e.g., extinguishment or oscillating flames and steady burns). Potential RCS recommendations are also identified.     

Food-related hazards in China: Consumers' perceptions of risk and trust in information sources

This paper identifies segments of Chinese consumers based on their perception of personal risk, how worried they are and their subjective knowledge about seven possible food-related hazards: additives, residues, counterfeit, inferior, genetically modified, deteriorated and nutritionally imbalanced food. Data were collected through a consumer survey conducted in Beijing (534 participants) and in Baoding (437 participants). Three clusters were identified: worried and knowledgeable consumers (60.1%), worried and ignorant consumers (21.7%) and moderately worried consumers (18.2%). The first two groups reported a high level of worry and high perception of personal risk about food-related hazards in China. The two hazards they were most worried about were counterfeit food and inferior quality food. Television, internet and personal communication were the three information channels most frequently used by participants to obtain information about food safety. Worried and ignorant consumers reported less frequent use of magazines, books and brochures compared with other consumers. Medical doctors, personal experience and research institutes were the three most trusted information sources for the first two groups of consumers. Moderately worried consumers only placed high levels of trust in medical doctors and themselves. Consumers' perceptions about the knowledge, honesty and concern of different information sources significantly and positively affected their trust in those sources. The study concludes by making recommendations as to how to improve communications with the different identified consumer segments and identifies future research required to expand its validity.     

Design of horizontal drains for the mitigation of liquefaction risk

Drainage is one of the most popular protecting measures to mitigate ground liquefaction. Deploying the drains horizontally may be convenient where conventional vertical ones cannot be used, like beneath existing structures. The spacing among drains must be designed to limit the pore pressure build-up during shaking. The usual assumptions of radial consolidation around vertical drains, stemming from the assumption of an infinite number of drains, may not be appropriate for horizontal ones, since the latter are generally arranged in few rows at a shallow depth, especially if drainage at the ground level is possible as well. Hence, existing solutions for vertical “earthquake” drains have been modified in this work to take into account such different geometrical features. The resulting solution has been validated against numerical and experimental sets of data. Charts covering a wide range of geometrical layouts, soil properties, and seismic actions are finally proposed. They can be used to design the drain spacing that is needed so as not to exceed the target value of excess pore pressure in the ground.     

Assumptions necessary and unnecessary to risk homoeostasis

This paper discusses recent criticisms of the theory of risk homoeostasis which has been put forward to explain the spatial, temporal and per capita traffic accident risk in a given jurisdiction, as well as their pattern of interrelation. Four assumptions have recently been proposed in the literature as being necessary for the theory to be valid. These were viewed as wanting and, therefore, presented as a challenge to the theory in question. In the present discussion, these four assumptions are examined on their conceptual pertinence. It is concluded that, without some major and some seemingly minor-yet theoretically crucial—modifications, none of these assumptions appear to be essential to the validity of the theory under debate.     

Risk perceptions and approaches in multi-organizations: A research review 2000–2012

Shared risks and opportunities set specific premises for risk management (RM) in temporary multi-organizations (TMOs). However, most project RM research is presented from the perspective of a single-organizational project delivery team or covers limited risk perceptions and RM approaches. This paper aims to address how well the body of knowledge on multi-organizational RM corresponds to a state-of-art understanding on project RM and to identify which gaps need to be addressed in future research. The review involves: 1) the preferred view of risk as threat and/or opportunity, 2) the nature of addressed risks as anticipated or unanticipated risks or unrealistic assumptions, 3) the role of the multi-organization as the source of risks and/or resources for risk management (RM), and 4) the allocation of risk responsibilities. The review covers research papers published between 2000 and 2012 in four journals: International Journal of Project Management (IJPM), Project Management Journal (PMJ), Journal of Construction Engineering and Management (JCEM), and IEEE Transactions on Software Engineering (TSE). 105 eligible research papers were identified. The results and conclusion outline the identified main gaps in multi-organizational RM research compared to the state-of-art RM research and TMO-specific characteristics. The results can be used to inform research agendas on more holistic and dynamic multi-organizational RM concepts.     

Transport mode preferences,risk perception and worry in a Norwegian urban population

The main aim of the present study was to compare risk perception among Norwegians (n = 512) living in the region of Oslo. This study was part of an ERANET 13 project entitled PETRIS, Perception of transport risk in France and Norway. The data collection was carried out in January 2011. The response rate was 51 percent. The results showed that respondents, divided in two groups according to their transport mode preferences, assessed differently risk perception in public and private transportation. Respondents who preferred collective transportation assessed the probability of experiencing criminality in collective transport modes as higher than those who preferred private modes. They were also more worried of experiencing accidents, criminality, and terror attacks in collective transportation. The relationship between transport mode preferences and use, risk perception and worry are discussed.