Multiobjective Optimization for the Asset Allocation of European Nonlife Insurance Companies

An optimal asset allocation is crucial for nonlife insurance companies. The most previous studies focused on this topic use a mono‐objective technique optimization. This technique usually allows the maximization of shareholders' expected utility. As nonlife insurance company is a complex system, it has many stakeholders other than shareholders. So, the satisfaction of the shareholders' expected utility cannot lead usually to the satisfaction of other stakeholders' objectives. Therefore, the focus on utility maximization can be a destruction source of other objectives such as productivity, competitiveness and solvency. Our developed model integrates simulation approach with a multiobjective particle swarm optimization algorithm. This model insures an optimal asset allocation that maximizes, simultaneously, shareholders expected utility and technical efficiency of European nonlife insurance companies. The empirical application conducts a comparison between the attained results with multiobjective optimization technique and mono‐objective technique to search the optimal asset allocation for nonlife insurance companies. Our results show that the investment portfolio will be more diversified between most available investment assets. In addition, any decision maker should take account of different stakeholders' objectives. Accordingly, multiobjective optimization allows us to find the best asset allocation that maximizes simultaneously expected utility and technical efficiency of nonlife insurance companies. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of performance anxiety on effort and performance in rock climbing: A test of processing efficiency theory

Abstract

Three studies examined the effort and performance of rock climbers in the context of processing efficiency theory. Anxiety was manipulated by different means in the three studies. In each study, the effort due only to the physical exertion of climbing was controlled for. Anxiety, effort, and performance were measured via self-report, an integrated heart rate measure, and belayer observation. Consistent with processing efficiency theory, the results showed that higher levels of anxiety were usually associated with higher levels of effort and commensurately higher levels of performance. However, the results also suggested that cognitive anxiety may not be the prime determinant of the effort and performance changes observed. Finally, the results suggested that other individual difference variables may play an important part in determining the extent to which individuals may be able to make use of anxiety-induced effort.     

时距知觉的扭曲:新异刺激效应

时距知觉会受到刺激新异性的影响,新异刺激的呈现时间往往被认为长于等时距重复出现的标准刺激的呈现时间.已有研究在解释这种主观的时距扩张现象时主要涉及三种假设:注意假设、唤醒假设和神经编码效能假设.研究中的变量混淆问题、跨通道效应和时间因素是今后研究中值得思考的几个问题.对于新异刺激效应产生的心理和神经机制,研究者们还存在着较大分歧.进一步探讨其心理和神经机制对理解时距知觉具有重要意义.     

Neurotic Nucleus and Test Anxiety

Undergraduate university students (N = 103) participated in a study of the relationship between test anxiety and the variables of trait anxiety, self-esteem, locus of control, mental ability, and gender. Results indicated bivariate associations between total test anxiety and the other measures except for mental ability. Further analyses revealed independent relationships between the “worry” component of test anxiety and the variables of trait anxiety, intemality, chance, and mental ability. We also found independent associations between the “emotionality” aspect of test anxiety and the measures of trait anxiety and chance.     

Effects of school-based interventions on motivation towards physical activity in children and adolescents: A systematic review and meta-analysis

IntroductionAssuming that motivation is the key to initiate and sustain beneficial health behaviors, the aim of this systematic review was to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards PA in school-aged children and adolescents.MethodsA comprehensive literature search was carried out in six electronic databases to identify randomized controlled trials and quasi-experimental trials examining the effects of PA interventions implemented during the regular school day, e.g., during physical education lessons or lunch breaks. Primary outcomes of interest were students' motivation, basic psychological needs, goal orientation, enjoyment, and motivational teaching climate in physical education. Meta-analyses were conducted for these outcomes using Comprehensive Meta-analysis software. Secondarily, intervention effects on students' PA behaviors were examined and the findings summarized narratively. Methodological quality of studies was evaluated using the Cochrane Collaboration's tool for assessing risk of bias for randomized trials; certainty of evidence on outcome level was evaluated using the GRADE approach.ResultsIn total, 57 studies carried out between 2001 and 2018 were included in this review. Sixteen individual meta-analyses were performed and revealed significant pooled effects for the outcomes enjoyment (g = 0.310), perceived autonomy (g = 0.152), identified regulation (g = 0.378), intrinsic motivation (g = 0.419), self-determination index (g = 0.672), task/mastery climate (g = 0.254), ego/performance climate (g = −0.438), autonomy supportive climate (g = 0.262), task goal orientation (g = 1.370), ego goal orientation (g = −0.188). The narrative data synthesis indicated an increase in students' PA behavior. The overall risk of bias was high across all studies and certainty of evidence of meta-analyzed outcomes ranged from very low to moderate. Moderate certainty of evidence was found for ego/performance climate and ego goal orientation. Conclusions: Meta-analyses suggest that school-based PA interventions may be effective in increasing a variety of motivational outcomes. However, the certainty of evidence was limited in the majority of outcomes. Further research is needed to identify effective intervention strategies that increase students’ motivation towards PA.     

Boundaries of American Identity: Relations Between Ethnic Group Prototypicality and Policy Attitudes

We sought to document that the extent to which different ethnic groups are perceived as embodying the American identity is more strongly linked to antiminority policy attitudes and acculturation ideologies among majority‐group members (European Americans) than among minority‐group members (Asian Americans or Latino/as). Participants rated 13 attributes of the American identity as they pertain to different ethnic groups and reported their endorsement of policy attitudes and acculturation ideologies. We found a relative consensus across ethnic groups regarding defining components of the American identity. However, European Americans were perceived as more prototypical of this American identity than ethnic minorities, especially by European American raters. Moreover, for European Americans but not for ethnic minorities, relative ingroup prototypicality was related to antiminority policy attitudes and acculturation ideologies. These findings suggest that for European Americans, perceptions of ethnic group prototypicality fulfill an instrumental function linked to preserving their group interests and limiting the rights afforded to ethnic minorities.     

Characterization of lower-limbs inter-segment coordination during the take-off extension in ski jumping

Take-off, the most important phase in ski jumping, has been primarily studied in terms of spatio-temporal parameters; little is known about its motor control aspects. This study aims to assess the inter-segment coordination of the shank-thigh and thigh-sacrum pairs using the continuous relative phase (CRP). In total 87 jumps were recorded from 33 athletes with an inertial sensor-based system. The CRP curves indicated that the thighs lead the shanks during the first part of take-off extension and that the shanks rotated faster at the take-off extension end. The thighs and sacrum first rotated synchronously, with the sacrum then taking lead, with finally the thighs rotating faster. Five characteristic features were extracted from the CRP and their relationship with jump length was tested. Three features of the shank-thigh pair and one of the thigh-sacrum pair reported a significant association with jump length. It was observed that athletes who achieved longer jumps had their thighs leading their shanks during a longer time, with these athletes also having a more symmetric movement between thighs and sacrum. This study shows that inter-segment coordination during the take-off extension is related to performance and further studies are necessary to contrast its importance with other ski jumping aspects.     

Sex differences in neural efficiency: Are they due to the stereotype threat effect?

The neural efficiency hypothesis postulates a more efficient use of brain resources in more intelligent people as compared to less intelligent ones. However, this relationship was found to be moderated by sex and task content. While the phenomenon of neural efficiency was previously supported for men when performing visuo-spatial tasks it occurred for women only when performing verbal tasks. One possible explanation for this finding could be provided by the well-studied phenomenon called stereotype threat. Stereotype threat arises when a negative stereotype of one’s own group is made salient and can result in behavior that confirms the stereotype. Overall, 32 boys and 31 girls of varying intellectual ability were tested with a mental rotation task, either under a stereotype exposure or a no-stereotype exposure condition while measuring their EEG. The behavioral results show that an activated negative stereotype not necessarily hampers the performance of girls. Physiologically, a confirmation of the neural efficiency phenomenon was only obtained for boys working under a no-stereotype exposure condition. This result pattern replicates previous findings without threat and thus suggests that sex differences in neural efficiency during visuo-spatial tasks may not be due to the stereotype threat effect.