Applications of Judd–Ofelt theory to praseodymium and samarium ions in phosphate glass

The Judd–Ofelt (J–O) theory has had a remarkable success in the characterization of radiative transitions in lanthanide doped solids. The purpose of this paper is to review the applications of the J–O theory to the Pr³⁺ and Sm³⁺ ions and to use this system as an occasion to appraise its validity and to clarify its limits. In this paper we dwell at length on the absorption and luminescence measurements of two glass samples doped with Pr³⁺ and Sm³⁺, because they are basic for the J–O treatment. The results obtained for the J–O theory application to phosphate glasses doped with Pr³⁺ and Sm³⁺ present two undesirable outcomes: (1) a positive value of parameter Ω₂ and (2) large uncertainties with which the three Judd–Ofelt parameters were obtained. The validity of the J–O theory for intensity analysis was also tested for Sm³⁺ doped in phosphate glass. The resulting Ω₂ was much lower than Ω₄. The first set parameters were obtained using all the levels for which f_exp. was available. The second set parameter values were evaluated without the ⁶F_1/2 and ⁶H_15/2 levels. The Ω_2,4,6 values given in these two sets clearly suggest that particular care should be taken while evaluating the Judd–Ofelt parameters as well as when these parameters are compared to other systems due to their strong dependence on the nature of levels.     

Risk, risk aversion and the optimal time to produce

This paper studies the order-fulfillment process of a supplier producing a customized capital good. When they decide at what time to begin production, suppliers in these industries typically face the following dilemma. On the one hand, their customers expect them to be responsive and the time that they are prepared to wait for the product is much shorter than the time needed to produce and deliver it. On the other hand, it is risky for the suppliers to start production before the customers confirm their orders due to inventory holding costs and the possibility of order cancellation. We offer a model to help understand this dilemma and investigate the comparative statics effects of lead time, lead time uncertainty and the risk aversion of the supplier. Relative to existing work, our model has two novel components: demand distribution updating and the supplier's risk attitude. Previous empirical studies reveal that the supplier is very conservative when commencing the order fulfillment. The studies attribute this to high holding and cancellation costs relative to the delay cost. Our model provides two alternative explanations. First, other than costs, when the supplier starts to produce depends also on how the distribution of the demand arrival time is updated as time progresses. Second, although the effect of increasing risk aversion of the supplier on the optimal time to produce is ambiguous, we show that it plays a major role in the decision and thus it alone may have caused the supplier to be conservative.     

The social innovation potential of ICT-enabled citizen observatories to increase eParticipation in local flood risk management

We live in the age of Big Data, yet many areas of environmental management are still suffering from a lack of relevant data, information and knowledge that impedes sound decision making in the face of change and increasing challenges. A highly relevant phenomenon is therefore the so-called citizen observatories whereby the observations of ordinary citizens, and not just those of professionals and scientists, are included in earth observation and environmental management. Advanced citizen observatories can enable a two-way communication paradigm between citizens and decision makers, potentially resulting in profound changes to local environmental management processes and, as such, in social innovation processes and outcomes. This paper analyses the social innovation potential of such ICT-enabled citizen observatories to increase eParticipation in local flood risk management. The findings from empirical research in two case study locations highlight the divergent roles that authorities conceive for citizens and the role(s) that citizens in practice assign to themselves. Moreover, given the institutional structures identified in these cases and the obligation of authorities to be accountable for their decisions, citizen observatories do not automatically imply that citizens will have a higher level of participation in flood risk management, nor that communication between stakeholders improves.     

Relative fatality risk curve to describe the effect of change in the impact speed on fatality risk of pedestrians struck by a motor vehicle

Models describing the relation between impact speed and fatality risk for pedestrians struck by a motor vehicle have frequently been used by practitioners and scientists in applying an S curve to visualize the importance of speed for the chance of survival. Recent studies have suggested that these risk curves are biased and do not give representative risk values. These studies present new fatality risk curves that show much lower risks of fatality than before, which has caused confusion and misconceptions about how these new curves should be interpreted, and how this should affect speed management policy.     

Errors and violations in relation to motorcyclists' crash risk

This study was conducted to: (a) develop a questionnaire that reliably measures the behaviour of motorcyclists and (b) test which types of behaviour predict motorcyclists' crash risk. A Motorcycle Rider Behaviour Questionnaire (MRBQ), consisting of 43 items to measure the self-reported frequency of specific riding behaviours, was developed and administered to a sample of motorcyclists (N=8666). Principal components analysis revealed a 5-factor solution (traffic errors, control errors, speed violations, performance of stunts and use of safety equipment). Generalised linear modelling showed that, while controlling for the effects of age, experience and annual mileage, traffic errors were the main predictors of crash risk. For crashes in which respondents accepted some degree of blame, control errors and speed violations were also significant predictors of crash risk. Implications of the findings are discussed in relation to deciding which countermeasures may be most effective at reducing motorcycle casualty rates.     

Role of macropore size in the mechanical properties and in vitro degradation of porous calcium phosphate cements

The goal of the present study was to investigate the effect of macropore size on the compressive strength and in vitro degradation of porous calcium phosphate cements (CPCs). For this purpose, a series of porous CPCs with three different macropore sizes (200-300 μm, 300-450 μm and 450-600 μm) and comparable porosity were prepared by salting-out method, and the study of in vitro degradation behavior was carried out under a constant fluid flow environment. The results showed that the increase in macropore size of CPCs with invariant porosity resulted in a decrease in the compressive strength but an increase in the degradation rate of CPCs significantly, suggesting the possibility that the degradation rate and compressive strength of biomaterials can be regulated by varying the macropore size while maintaining the porosity unchanged.     

Getting beyond ‘grin and bear it’ in the practice of risk management

Risk perception researchers frequently notice major discrepancies between expert judgment and lay opinion concerning the identity of ‘large’ risks. These discrepancies are particularly disconcerting because they lead to a significant misallocation of scarce resources devoted to public risk management. Yet, democratic decision-making also appeals to many risk perception researchers, and some see such little prospect for a solution thaty they seem close to surrendering to decision-making based on lay risk perception. This article argues that such a ‘grin and bear it’ strategy is also unsatisfactory; that risk perceptions are unstable grounds for decision-making; that expert risk assessment and lay risk perception differ by design rather than accident; that risk experts' search for ‘virtuous lawmakers’ who would make public decisions for the greatest public good is a vain one; that the dissonance risk perception researchers now observe will likely get worse in the new information age; and that risk perception researchers need to return to first principles to find solutions to these dilemmas. In particular, the gap between expert judgment and lay perception will close only when non-experts are permitted and expected to make their own risk management decisions, so far as that is possible, while bearing full responsibility for their choices.     

Finance, Policy and Industrial Dynamics—The Rise of Co-productions in the Film Industry

This paper explores the growing phenomenon of international co-productions in the film industry. We argue that the rise of co-productions is part of a wider narrative of financial and institutional innovation shaping industrial organization in the film industry. This narrative centres on film finance as a central risk distribution mechanism, and discusses how changes in film support policy, increased tax competition, the search for finance and an abundance of inflowing capital are increasingly driving industrial dynamics in the film industry.     

Traffic accident statistics and risk perceptions in Japan and the United States

Several recent studies have concluded that Japan and the US have different risk cultures. This study examines the actual risk environments faced by citizens in the two countries, in the domain of traffic safety, as a possible source of differences in risk perceptions. The study contrasts traffic-accident risks from several points of view (e.g. car drivers, motorcyclists, bicyclists and pedestrians) and risk statistics (e.g. death rates, relative fatality risks, and accident lethality). Results clarify the traffic risks in the two countries and confirm their potential for explaining cross-national differences in risk perceptions.     

An approach for using risk assessment in risk-informed decisions on plant-specific changes to the licensing basis

This paper discusses an acceptable approach that the US Nuclear Regulatory Commission staff has proposed for using Probabilistic Risk Assessment in making decisions on changes to the licensing basis of a nuclear power plant. First, the overall philosophy of risk-informed decision-making, and the process framework are described. The philosophy is encapsulated in five principles, one of which states that, if the proposed change leads to an increase in core damage frequency or risk, the increases must be small and consistent with the intent of the Nuclear Regulatory Commission's Safety Goal Policy Statement. The second part of the paper discusses the use of PRA to demonstrate that this principle has been met. The discussion focuses on the acceptance guidelines, and on comparison of the PRA results with those guidelines. The difficulties that arise because of limitations in scope and analytical uncertainties are discussed and approaches to accommodate these difficulties in the decision-making are described.     

On the use of risk acceptance criteria in the offshore oil and gas industry

Risk acceptance criteria, as upper limits of acceptable risks, have been used for offshore activities on the Norwegian Continental Shelf for more than 20 years. The common thinking has been that risk analyses and assessments cannot be conducted in a meaningful way without the use of such criteria. The ALARP principle also applies, but the risk acceptance criteria have played a more active role in the assessment processes than seen for example in the UK. Recently there has, however, been a discussion about the suitability of risk acceptance criteria to assess and control risks. The purpose of this paper is to contribute to this discussion by presenting and discussing a risk analysis regime that is not based on the use of risk acceptance criteria at all. We believe that we can do better if cost-effectiveness (in a wide sense) is the ruling thinking rather than adoption of pre-defined risk acceptance limits. This means a closer resemblance with the ALARP principle as adopted in the UK and other countries, but is not a direct application of this practice. Also the building blocks of the common way of applying the ALARP principle are reviewed. The Norwegian offshore oil and gas industry is the starting point, but the discussion is to large extent general.     

The fatality and injury risk of light truck impacts with pedestrians in the United States

In the United States, passenger vehicles are shifting from a fleet populated primarily by cars to a fleet dominated by light trucks and vans (LTVs). Because light trucks are heavier, stiffer, and geometrically more blunt than passenger cars, they pose a dramatically different type of threat to pedestrians. This paper investigates the effect of striking vehicle type on pedestrian fatalities and injuries. The analysis incorporates three major sources of data, the Fatality Analysis Reporting System (FARS), the General Estimates System (GES), and the Pedestrian Crash Data Study (PCDS). The paper presents and compares pedestrian impact risk factors for sport utility vehicles, pickup trucks, vans, and cars as developed from analyses of US accident statistics. Pedestrians are found to have a two to three times greater likelihood of dying when struck by an LTV than when struck by a car. Examination of pedestrian injury distributions reveals that, given an impact speed, the probability of serious head and thoracic injury is substantially greater when the striking vehicle is an LTV rather than a car.     

Findings from the Candrive/Ozcandrive study: Low mileage older drivers,crash risk and reduced fitness to drive

Previous research has found that only older drivers with low annual driving mileages had a heightened crash risk relative to other age groups. These drivers tend to drive mainly in urban areas, where the prevalence of complex traffic situations increases crash risk. However it might also be that some drivers may have reduced their driving due to perceived or actual declines in driving fitness.     

Human health risk screening due to consumption of fish contaminated with chemical warfare agents in the Baltic Sea

Chemical warfare agents (CWAs) have been disposed of in various fashions over the past decades. Significant amounts of CWA, roughly 11,000 ton, have been dumped in the Baltic Sea east of the island Bornholm following the disarmament of Germany after World War II. This has caused concerns over potential human and environmental health risks, and resulted in restrictions on fishing in the dumpsite area. The purpose of this paper is to assess the potential indirect human health risks due to consumption of CWA-contaminated fish from the dumpsite area east of Bornholm. Earlier studies suggest that the fish community may be at risk from CWA exposure in the Bornholm basin. Moreover, elevated frequencies of lesions on fish caught in a CWA dumpsite in the Mediterranean Sea have been observed. The fish at the Mediterranean dumpsite had elevated total arsenic (As) concentrations in their tissue, and elevated total As levels were also observed in the sediment. Elevated total sediment As concentrations have also been recorded in CWA dumpsites in the Skagerrak and the Baltic Sea. Triphenylarsine and sulfur mustard gas (Yperite) are the CWAs with the greatest indirect human health risk potential. There are recognized uncertainties concerning Yperite's and CWA-derived arsenical's fate and speciation in the environment, as well as their inherent toxicity, warranting caution and further site-specific environmental and human health risk assessments of CWAs dumped in the Bornholm basin.     

How to identify the key factors that affect driver perception of accident risk. A comparison between Italian and Spanish driver behavior

Road crashes can be caused by different factors, including infrastructure, vehicles, and human variables. Many research studies have focused solely on identifying the key factors that cause road crashes. From these studies, it emerged that human factors have the most relevant impact on accident severity. More specifically, accident severity depends on several factors related directly to the driver, i.e., driving experience, driver's socio-economic characteristics, and driving behavior and attitudes. In this paper, we investigate driver behaviors and attitudes while driving and specifically focus on different methods for identifying the factors that most affect the driver's perception of accident risk. To this end, we designed and conducted a survey in two different European contexts: the city of Cosenza, which is located in the south of Italy, and the city of Granada, which is located in the south of Spain. Samples of drivers were contacted for their opinions on certain aspects of driving rules and attitudes while driving, and different types of questions were addressed to the drivers to assess their judgments of these aspects. Consequently, different methods of data analysis were applied to determine the aspects that heavily influence driver perception of accident risk. An experiment based on the stated preferences (SP) was carried out with the drivers, and the SP data were analyzed using an ordered probit (OP) model. Interesting findings emerged from different analyses of the data and from the comparisons among the data collected in the two different territorial contexts. We found that both Italian and Spanish drivers consider driving in an altered psychophysical state and violating the overtaking rules to be the most risky behaviors.     

A combined usage of stochastic and quantitative risk assessment methods in the worksites: Application on an electric power provider

An individual method cannot build either a realistic forecasting model or a risk assessment process in the worksites, and future perspectives should focus on the combined forecasting/estimation approach. The main purpose of this paper is to gain insight into a risk prediction and estimation methodological framework, using the combination of three different methods, including the proportional quantitative-risk-assessment technique (PRAT), the time-series stochastic process (TSP), and the method of estimating the societal-risk (SRE) by F-N curves. In order to prove the usefulness of the combined usage of stochastic and quantitative risk assessment methods, an application on an electric power provider industry is presented to, using empirical data.     

Willingness to pay for road safety and estimates of the risk of death: evidence from a Swedish contingent valuation study

We examine how WTP for a reduction in road-mortality risk varies with different individual characteristics and how subjective mortality-risk estimates differ from objective (statistical) mortality-risk values. Using data from a Swedish contingent valuation study, we find some support that WTP declines with age and background risk, but we find no support that WTP varies with health status. Further, we find that respondents underassess their own mortality risks, both road- and total-mortality risks, compared to the objective risk measures for Sweden at the time of the survey.     

成功的关键：工业和商业间交接区域的后勤

市场的不断变化要求企业富于柔性以适应变化中的周边条件。在整个增值过程中,后勤的定位和组织是控制企业过程从而确保成功的决定性前提条件。本文从组织角度在强调后勤潜能的同时,突出其重要性。     

Latent risk and trend models for the evolution of annual fatality numbers in 30 European countries

In this paper a unified methodology is presented for the modelling of the evolution of road safety in 30 European countries. For each country, annual data of the best available exposure indicator and of the number of fatalities were simultaneously analysed with the bivariate latent risk time series model. This model is based on the assumption that the amount of exposure and the number of fatalities are intrinsically related. It captures the dynamic evolution in the fatalities as the product of the dynamic evolution in two latent trends: the trend in the fatality risk and the trend in the exposure to that risk. Before applying the latent risk model to the different countries it was first investigated and tested whether the exposure indicator at hand and the fatalities in each country were in fact related at all. If they were, the latent risk model was applied to that country; if not, a univariate local linear trend model was applied to the fatalities series only, unless the latent risk time series model was found to yield better forecasts than the univariate local linear trend model. In either case, the temporal structure of the unobserved components of the optimal model was established, and structural breaks in the trends related to external events were identified and captured by adding intervention variables to the appropriate components of the model. As a final step, for each country the optimally modelled developments were projected into the future, thus yielding forecasts for the number of fatalities up to and including 2020.     

A historical overview of probabilistic risk assessment development and its use in the nuclear power industry: a tribute to the late Professor Norman Carl Rasmussen

This paper reviews the historical development of the probabilistic risk assessment (PRA) methods and applications in the nuclear industry. A review of nuclear safety and regulatory developments in the early days of nuclear power in the United States has been presented. It is argued that due to technical difficulties for measuring and characterizing uncertainties and concerns over legal challenges, safety design and regulation of nuclear power plants has primarily relied upon conservative safety assessment methods derived based on a set of design and safety principles. Further, it is noted that the conservatism adopted in safety and design assessments has allowed the use of deterministic performance assessment methods. This approach worked successfully in the early years of nuclear power epoch as the reactor design proved to be safe enough. However, it has been observed that as the conservative approach to design and safety criteria proved arbitrary, and yielded inconsistencies in the degree to which different safety measures in nuclear power plants protect safety and public heath, the urge for a more consistent assessment of safety became apparent in the late 1960s. In the early 1970s, as a result of public and political pressures, then the US Atomic Energy Commission initiated a new look at the safety of the nuclear power plants through a comprehensive study called ‘Reactor Safety Study’ (WASH-1400, or ‘Rasmussen Study’—after its charismatic study leader Professor Norman Rasmussen of MIT) to demonstrate safety of the nuclear power plants. Completed in October 1975, this landmark study introduced a novel probabilistic, systematic and holistic approach to the assessment of safety, which ultimately resulted in a sweeping paradigm shift in safety design and regulation of nuclear power in the United States in the turn of the Century. Technical issues of historic significance and concerns raised by the subsequent reviews of the Rasmussen Study have been discussed. Effect of major events and developments such as the Three Mile Island accident and the Nuclear Regulatory Commission and the Nuclear Industry sponsored studies on the tools, techniques and applications of the PRA that culminated in the present day risk-informed initiatives has been discussed.