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Often our expectations are set by sampling many times from the same distribution. When that distribution changes, so should our expectations. If we want to decide whether to take our umbrella today we need to have tracked, and updated, our estimate of the probability of rain by reference to recent temperatures and precipitation. Under debate is whether we update our mental estimates of probabilities given each new incoming piece of evidence or whether we stick with a current estimate until it becomes clearly in need of change. Previous research has suggested that participant estimates of running probabilities are not updated on every trial, but only intermittently. This has been used to support change-point models of probability updating. However, such a pattern could also be explained by the way common laboratory procedures impose a motor cost to update the probability report. This study was designed to remove the motor confound. Our procedure required similar motor actions for both changing and maintaining one’s probability estimate. At a group level, motor cost did affect updating frequency and removing the default response option encouraged more frequent updating. However, intermittent updating response patterns did not disappear completely. Despite this equivalence in response effort, some participants, even when forced to make a new estimate on every trial, continued to update rarely while other participants meticulously updated every trial. We conclude deliberate updating frequency is heterogenous but intermittent updating is not simply an artifact of motor cost. [ABSTRACT FROM AUTHOR]

The novel coronavirus COVID-19 pandemic is associated with elevated rates of anxiety and relatively lower compliance with public health guidelines in younger adults. To develop strategies for reducing anxiety and increasing adherence with health guidelines, it is important to understand the factors that contribute to anxiety and health compliance in the context of COVID-19. Earlier research has shown that greater perceived risk of negative events and their costs are associated with increased anxiety and compliance with health behaviors, but it is unclear what role they play in a novel pandemic surrounded by uncertainty. In the present study we measured (1) perceived risk as the self-reported probability of being infected and experiencing serious symptoms due to COVID-19 and (2) perceived cost as financial, real-world, physical, social, and emotional consequences of being infected with COVID-19. Worry was assessed using the Penn State Worry Questionnaire (PWSQ) and health compliance was measured as endorsement of the World Health Organization (WHO) health directives for COVID-19. Our results showed that greater perceived risk and costs of contracting the COVID-19 virus were associated with greater worry and while only costs were associated with greater compliance with health behaviors. Neither self-reported worry nor its interaction with cost estimates was associated with increased engagement in health behaviors. Our results provide important insight into decision making mechanisms involved in both increased anxiety and health compliance in COVID-19 and have implications for developing psychoeducational and psychotherapeutic strategies to target both domains.

In the context of flexible operation and bidirectional line flows in modern transmission systems, suitable line flows are essential for safe, secure and stable power systems. Improper line flows may deteriorate stability and longevity of transmission lines. To avoid line outage and faults, improvement in thermal margin of conductors by regulating line flows is a practical consideration. To maintain and control the line flows, the unified power flow controller (UPFC) is the most appropriate compensating device. Thus, in this study, line flows are considered as state variables to optimise several functions, like, voltage deviation index, active and reactive power losses, temperature of conductors and cost of UPFC. The UPFC is modelled with practical losses like switching, coupling and internal transmission losses. Suitable line flows are obtained for the 30‐bus and 57‐bus test systems by applying an adaptive‐version of the wind‐driven optimisation (AWDO) algorithm. The AWDO is designed using two innovative tuning parameters: a decaying friction coefficient to reduce the probability of stagnation, and an adaptive velocity function to maintain diversity. The results are compared among different cases of line flows, validating the necessity of the technical challenge. The performance of AWDO is compared with other techniques, suggesting its superiority over other methods. [ABSTRACT FROM AUTHOR]

Despite the emphasis on threat appraisal in cognitive models of anxiety, self-report measures of related processes in children and adolescents have been lacking. This paper reports on the development and preliminary psychometric evaluation of a new measure of threat appraisal for children and adolescents - the Threat Appraisal Questionnaire for Children (TAQ-C). Based on current conceptualisations of threat appraisal, the TAQ-C was designed to index the construct across three dimensions: probability, cost, and coping difficulties. Confirmatory Factor Analysis was used to examine this structure in a community sample of n = 312 children (ages 9-15 years, 55% female). Results indicated that the scores on the instrument capture three factors (Probability, Cost and Coping difficulties). Moreover, a model in which the 1st-order factors loaded significantly on a single 2nd order factor of threat in general, was supported. The TAQ-C was found to demonstrate good internal consistency, and acceptable levels of test-retest reliability within a 3-4 week interval, when evaluated with a subsample of n = 51 children. Support for convergent validity was demonstrated, with TAQ-C scores found to correlate strongly with existing measures of child anxiety, and conceptually related cognitive processes. Divergent validity was also evidenced, with low correlations found between TAQ-C scores and the unrelated construct measure of Hyperactivity-Inattention. The TAQ-C, therefore, appears to be a promising measure with a range of potential applications for child and adolescent settings. [ABSTRACT FROM AUTHOR]

Background For women who have had a previous low transverse cesarean delivery, the decision to undergo a trial of labor after cesarean (TOLAC) or an elective repeat cesarean delivery (ERCD) has important clinical and economic ramifications. Objectives To evaluate the cost-effectiveness of the alternative choices of a TOLAC and an ERCD for women with low-risk, singleton gestation pregnancies. Methods We searched EMBASE, MEDLINE, CINAHL, Cochrane Library, EconLit, and the Cost-Effectiveness Analysis Registry with no language, publication, or date restrictions up until October 2015. Studies were included if they were primary research, compared a TOLAC with an ERCD, and provided information on the relative cost of the alternatives. Abstracts and partial economic evaluations were excluded. Results Of 310 studies initially reviewed, 7 studies were included in the systematic review. In the base-case analyses, 4 studies concluded that TOLAC was dominant over ERCD, 1 study found ERCD to be dominant, and 2 studies found that although TOLAC was more costly, it offered more benefits and was thus cost-effective from a population perspective when considering societal willingness to pay for better outcomes. In sensitivity analyses, cost-effectiveness was found to be dependent on a high likelihood of TOLAC success, low risk of uterine rupture, and low relative cost of TOLAC compared with ERCD. Conclusions For women who are likely to have a successful vaginal delivery, routine ERCD may result in excess morbidity and cost from a population perspective. [ABSTRACT FROM AUTHOR]

Supporting efficient connections by synchronizing vehicle arrival time and passengers' walking time at a transfer hub may significantly improve service quality, stimulate demand, and increase productivity. However, vehicle travel times and walking times in urban settings often varies spatially and temporally due to a variety of factors. Nevertheless, the reservation of slack time and/or the justification of vehicle arrival time at the hub may substantially increase the success of transfer coordination. To this end, this paper develops a model that considers probabilistic vehicle arrivals and passengers walking speeds so that the slack time and the scheduled bus arrival time can be optimized by minimizing the total system cost. A case study is conducted in which the developed model is applied to optimize the coordination of multiple bus routes connecting at a transfer station in Xi'an, China. The relationship between decision variables and model parameters, including the mean and the standard deviation of walking time, is explored. It was found that the joint impact of probabilistic vehicle arrivals and passengers' walking time significantly affects the efficiency of coordinated transfer. The established methodology can essentially be applied to any distribution of bus arrival and passenger walking time. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

On the basis of semi-analytical final elements method data validity research and research of effective determination of fracture mechanics parameters for bodies of revolution in non-stationary dynamics problems were conducted. New method of J-integral calculation and crack approximation under dynamic impact are presented.

The determination of a project's cost contingency is a pervasive problem as the amount that is incorporated into an estimate is invariably insufficient to accommodate a project's actual cost overrun. The cost overruns experienced in 49 road construction projects procured using traditional lump contracts are analyzed. The theoretical probability distributions are fitted to cost overrun data derived from the sampled projects whose contract values ranged from AU $0.5 and AU $97 million. Goodness of fit tests are used in conjunction with probability-probability (P-P) plots to compare the sample distribution from the known theoretical distribution. A log logistic probability density function (PDF) was found to best describe the behavior of cost overruns. The cumulative distribution function is then used to determine a realistic probability of a cost overrun being experienced from the point at which a contract is awarded. This is required so that public sector clients can determine an appropriate contingency at contract award, which takes into account the nuances that contribute to increasing project costs. The research findings and methodology adopted to determine the best fit probability distribution provides a more robust approach for governing a construction contingency for road construction projects so that they can be procured successfully. [ABSTRACT FROM AUTHOR]

A model for project budgeting and scheduling with uncertainty is developed. The traditional critical-path method (CPM) misleads because there are few, if any, real-life deterministic situations for which CPM is a great match; program evaluation and review technique (PERT) has been seen to have its problems, too (e.g., merge bias, unavailability of data, difficulty of implementation by practitioners). A dual focus on the distributions of the possible errors in the time and cost estimates and on the reliability of the estimates used as planned values suggests an approach for developing reliable schedules and budgets with buffers for time and cost. This method for budgeting and scheduling is executed through either simulation or a simple analytical approximation. The dynamic buffers provide much-needed flexibility, accounting for the errors in cost and duration estimates associated with planning any real project, thus providing a realistic, practical, and dynamic approach to planning and scheduling. [ABSTRACT FROM AUTHOR]

Abstract: A new method is designed for military software pricing, which is enlightened from binomial tree option pricing model. Firstly, it is constructed about the military software pricing model based on binomial tree. Secondly, computation method is shown later. Thirdly, the applicability of this computation method is demonstrated by an example. According to the calculation results, it is found out that the most two important variables are initial value of military software and successful probability of every stage, which are of strong effects to the price of military software. In addition, it is also concluded that value created in coding stage is usually smaller than value created in requirements stage and design stage. [Copyright &y& Elsevier]

Abstract: A new method is designed for military software pricing, which is enlightened from binomial tree option pricing model. Firstly, it is constructed about the military software pricing model based on binomial tree. Secondly, computation method is shown later. Thirdly, the applicability of this computation method is demonstrated by an example. According to the calculation results, it is found out that the most two important variables are initial value of military software and successful probability of every stage, which are of strong effects to the price of military software. In addition, it is also concluded that value created in coding stage is usually smaller than value created in equirements stage and design stage. [Copyright &y& Elsevier]

Four experiments investigated the effects of transactional content on temporal and probabilistic discounting of costs. Kusev, van Schaik. Ayton, Dent, and Chater (2009) have shown that content other than gambles can alter decision-making behavior even when associated value and probabilities are held constant. Transactions were hypothesized to lead to similar effects because the cost to a purchaser always has a linked gain, the purchased commodity. Gain amount has opposite effects on delay and probabilistic discounting (e.g., Benzion, Rapoport, & Yagil, 1989: Green. Myerson, & Ostaszewski, 1999), a finding that is not consistent with descriptive decision theory (Kahneman & Tversky, 1979; Loewenstein & Prelec. 1992). However, little or no effect on discounting has been observed for losses or costs. Experiment 1, using transactions, showed parallel effects for temporal and probabilistic discounting: : Smaller amounts were discounted more than large amounts. As the cost rises, people value the commodity more, and they consequently discount less. Experiment 2 ruled out a possible methodological cause for this effect. Experiment 3 replicated Experiment 1. Experiment 4. using gambles, .showed no effect for temporal discounting, because of the absence of the linked gain, but the same effect for probabilistic discounting, because prospects implicitly introduce a linked gain (Green et al., 1999: Prelec & Loewenstein, 1991). As found by Kusev et al. (2009), these findings are not consistent with decision theory and suggest closer attention should be paid to the effects of content on decision making. [ABSTRACT FROM AUTHOR]

We used historical records of damaging landslides triggered by rainstorms and a newly developed Probabilistic Landslide Assessment Cost Estimation System (PLACES) to estimate the numbers and direct costs of future landslides in the 10-county San Francisco Bay region. Historical records of damaging landslides in the region are incomplete. Therefore, our estimates of numbers and costs of future landslides are minimal estimates. The estimated mean annual number of future damaging landslides for the entire 10-county region is about 65. Santa Cruz County has the highest estimated mean annual number of damaging future landslides (about 18), whereas Napa, San Francisco, and Solano Counties have the lowest estimated mean numbers of damaging landslides (about 1 each). The estimated mean annual cost of future landslides in the entire region is about US $14.80 million (year 2000 $). The estimated mean annual cost is highest for San Mateo County ($3.24 million) and lowest for Solano County ($0.18 million). The annual per capita cost for the entire region will be about $2.10. Santa Cruz County will have the highest annual per capita cost at $8.45, whereas San Francisco County will have the lowest per capita cost at $0.31. Normalising costs by dividing by the percentage of land area with slopes equal to or greater than 17% indicates that San Francisco County will have the highest cost per square km ($7,101), whereas Santa Clara County will have the lowest cost per square km ($229). These results indicate that the San Francisco Bay region has one of the highest levels of landslide risk in the United States. Compared with landslide cost estimates from the rest of the world, the risk level in the Bay region seems high, but not exceptionally high. [ABSTRACT FROM AUTHOR]

This study investigated developmental differences in the relationship of probability and cost estimates to worrying. Adults, younger children ( M age = 8.67 years) and older children ( M age = 11.06 years) rated the extent to which they worry about a list of negative social and physical outcomes and provided subjective probability and cost estimates for the same outcomes. Adults reported worrying more about social outcomes and rated them as less ‘bad’ (or costly) but more likely to occur than physical outcomes. Unlike adults, children in both age groups reported worrying more about physical outcomes. However, similar to adults, they also rated social outcomes as less ‘bad’ but more likely to occur than physical outcomes. Regression analyses showed that probability ratings were the best predictors of worry in adults, both probability and cost ratings equally predicted worry in older children, but only cost ratings predicted worry in younger children. [ABSTRACT FROM AUTHOR]

Abstract: This study compared estimations of the probability and cost of negative events occurring made by patients with post-traumatic stress disorder (PTSD) (n =43), patients with other anxiety disorders (n =29) and non-patients’ (n =35). Prior to treatment PTSD patients overestimated the probability and cost of all types of traumatic events occurring relative to non-patients, and overestimated the probability and cost of the specific type of traumatic event that they had been traumatized by relative to the anxious controls as well as non-patients. These judgment biases were specific to traumatic events and did not generalise to all negative events. PTSD patients’ estimations of the probability and cost of traumatic events were significantly reduced following treatment, and were no longer significantly different from those of non-patients. Results suggest that patients with PTSD show specific judgment biases in the estimation of probability and cost, which can be successfully modified by cognitive therapy. [Copyright &y& Elsevier]

The need for information security is self-evident. The pervasiveness of this critical topic requires primarily risk assessment and management through quantitative means. To do an assessment, repeated security probes, surveys, and input data measurements must be taken and verified toward the goal of risk mitigation. One can evaluate risk using a probabilistically accurate statistical estimation scheme in a quantitative security meter (SM) model that mimics the events of the breach of security. An empirical study is presented and verified by discrete-event and Monte Carlo simulations. The design improves as more data are collected and updated. Practical aspects of the SM are presented with a real- world example and a risk-management scenario. [ABSTRACT FROM AUTHOR]

Contingent valuation has become one of the dominant methods for valuing nonmarketed environmental goods, as well as for damage assessment due to natural hazards. In this study, the method is applied for evaluating the household willingness to pay for a flood control project in an impoverished periphery of Rio de Janeiro, Brazil. Theoretical validity is analyzed via a binary logistic regression, which describes the impact of sociodemographic, dwelling characteristics, and flood related variables on the willingness to pay for the project. Analysis of content validity indicates a series of characteristics—uncertainty, novelty, lack of well-differentiated values, institutional setting, and entitlement structure—which appear to drastically limit the use of contingent valuation for flood control projects in low income areas of developing countries. The study concludes that the method, in it’s current formulation, is not appropriate for use in policy decisions about flood control investments in areas described by a concentration of low income households in developing countries. [ABSTRACT FROM AUTHOR]

An important up-stream activity in the overall design of a system is the so-called functional design wherein the means and tolerances of the design variables are determined with respect to the competing demands of quality and cost. In this article probability constrained optimization is invoked to produce a functional design that focuses on the goal of design for Six Sigma (i.e., improved customer satisfaction, robustness, and predictable cost levels). Herein, a maximum system probability of nonconformance is obtained from a prescribed defect rate that in turn provides the primary design constraint. The production cost provides the objective function to be minimized in order to allocate the design parameters. All three quality metrics (e.g., target/larger/smaller-is-best) and robustness are inherent in the approach. The design of an electro-mechanical servo system serves as a case study wherein three responses are related to three control variables and two noise variables by mechanistic models. Designs for selected defect rates show the practicality and potential of the approach. [ABSTRACT FROM AUTHOR]

Abstract: The relation between worrying and individuals’ concerns was examined in a sample of 197 college students. Participants described the five undesirable outcomes that they thought about most often, indicated how likely they thought the outcomes were, and how upset they would be by them. Worry severity was measured using the Penn State Worry Questionnaire. The relation between worry severity and the life domains about which individuals were concerned was quite weak. In contrast, as predicted, greater worry was associated with higher probability and cost estimates. In addition, cost estimates moderated the relation between worry severity and probability estimates. The potential importance of perceived threat for understanding worrying is discussed. [Copyright &y& Elsevier]

Abstract: Modern maintenance strategies for deteriorating structures are typically based on minimizing total cost. Extensions of this concept into the nondeterministic range allow to take into account the uncertainty in total cost. In this paper, the probability of exceeding a total cost threshold is included in the structure maintenance optimization problem. In addition, the probabilities of violating acceptable levels of safety and condition are computed. Based on this, an optimization task can be formulated and solved in which these probabilities can be included into the formulation of the objective function and the constraint conditions. Smoothing of the Monte-Carlo-based results is carried out utilizing a smoothing procedure by regression methods which are well-known for the response surface approach. Both time-based maintenance and performance-based maintenance are taken into account. The total maintenance cost is minimized with respect to parameters of both types of maintenance. Taking into account the cost of failure, optimal values for the threshold safety level and the time interval between subsequent maintenance applications are obtained. It is shown that different design parameters can lead to the same total cost thus allowing for a trade-off between time-based maintenance and performance-based maintenance at the discretion of the structure maintenance manager. [Copyright &y& Elsevier]

The section presents abstracts of studies on pediatrics which are available in the Internet section of the journal PEDIATRICS. The Health and Well-Being of Caregivers of Children With Cerebral Palsy by Parminder Raina, Maureen O' Donnell, Peter Rosenbaum, Jamie Brehaut, Stephen D.Walter, Dianne Russell, Marilyn Swinton, Bin Zhu and Ellen Wood. Utilization and Costs for Children Who Have Special Health Care Needs and Are Enrolled in a Hospital-Based Comprehensive Primary Care Clinic by Steve Berman, Michael Rannie, Laurie Moore, Ellen Elias, Leonard J.Dryer and M. Douglas Jones Jr. Probability of Coincident Vaccination in the 24 or 48 Hours Preceding Sudden Infant Death Syndrome Death in Australia by Julia M.L.Brotherton, Brynley P.Hull, Andrew Hayen, Heather F. Gidding and Margaret A. Burgess. Risk Factors Associated With Latent Tuberculosis Infection in Mexican American Children by Janine Young and Mary E.O' Connor.

In order to adequately handle the huge increase in traffic over the past three decades, most North American and European countries invested enormous funds in building highway networks. Nowadays, most of these networks are complete or close to completion. The biggest challenge highway agencies and departments of transportation face is the maintenance of these networks, keeping them safe and serviceable, with limited funds. The use of consistent measures of safety is fundamental for the development of optimum strategies for bridge maintenance. The analysis of safety on a component basis is a gross approximation of the real system performance of a bridge. In this paper, a model using lifetime functions to evaluate the overall system probability of survival of existing bridges, under maintenance or no maintenance, is proposed. In this model, bridges are modeled as systems of independent and/or correlated components. The proposed model is applied to an existing bridge located in Denver, Colorado, and the optimal maintenance strategy of this bridge is obtained in terms of service life extension and cumulative maintenance cost. [Copyright &y& Elsevier]

Individuals with Social Phobia (SP) (n=23) and Panic Disorder (n=22), and a non-anxious comparison (NAC) group (n=62) rated the probability and cost of negative outcomes in the physical and the social domains. Overall, participants rated physical events as less probable but more costly than social events. Compared to the non-anxious group, participants with Social Phobia made significantly higher probability and cost estimates for social events, but not for physical events. Multiple regression analyses demonstrated that perceived cost of negative social events was the strongest unique predictor of scores on the Fear of Negative Evaluation Scale (FNE). Participants with Panic Disorder made significantly higher probability and cost estimates for both physical and social outcomes, compared to non-anxious participants. Both physical probability and social cost estimates predicted scores on the Body Sensations Questionnaire (BSQ). Findings support the disorder-specificity of cognitive biases in Social Phobia, but suggest that individuals with Panic Disorder have a wider range of judgment biases than previously thought. [Copyright &y& Elsevier]

John Raftery (1993), in his Inaugural Lecture at the University of Greenwich, suggested that project cost estimates be presented in the form of cumulative probability functions (termed here 'Raftery curves') rather than the current practice of single-point estimates. This paper describes a method for the empirical construction of Raftery curves for tender price forecasts, which then is applied to ten previously published data sets gathered throughout the world. In comparing the resulting curves, the most consistent feature is shown to be the shift associated with to the number of bidders entering bids for contracts. This is examined both in terms of bias and consistency. Contrary to some previous studies, no evidence is found of any trends related to the value size of projects. [ABSTRACT FROM AUTHOR]

Treatment of correlation between variables is necessary for deriving any theoretical distribution of the project cost of buildings. This paper highlights some often ignored theoretical requirements necessary for a rigorous treatment of correlations. The condition for a positive definite correlation matrix is described, along with an analytical procedure and a computer program developed to verify the positive definite condition when correlation coefficients between input variables are estimated using historical data. The analytical procedure and the developed computer program can be used in any application that obtains correlation information from historical data or as subjective judgements to be used in a functional relationship. A new concept called induced correlation is suggested to define and to treat correlation between derived variables that arise from the common (shared) primary variables in their functional forms. A published numerical example is used to highlight the stages where correlation between variables can have an impact on the estimation of moments (estimated expected value and estimated standard deviation) for the project cost of buildings, and to demonstrate the improvement in the estimation of the standard deviation of project cost as a result of treating correlations in risk analysis. [ABSTRACT FROM AUTHOR]

A systematic methodology extends CPM project planning to allow for uncertainties, decision points, alternative courses of action, and likely changes and failures white executing the plan. Stochastic scheduling is carried out in eight steps. (1) The basic process and network are defined. (2) Uncertainty conditions are specified. (3) These conditions are formulated as a set of probability states, with corresponding durations and costs. (4) An augmented stochastic network is constructed. (5) From average values, durations and costs, a deterministic network is solved to provide an approximate picture of expected outcomes. (6) The stochastic network is solved, using a simulator; and the uncertainty effects of the stochastic conditions are analysed. (7) The effects of individual conditions on overall uncertainty are analysed. (8) An attempt is made to eliminate or modify those conditions contributing the most to uncertainty. The number of iterations needed to obtain a satisfactory simulation is also discussed. The stability of time and cost distributions is found to increase as the square root of the number of iterations. [ABSTRACT FROM AUTHOR]