Trading transforms of non-weighted simple games and integer weights of weighted simple games

Theory and Decision - This study investigates simple games. A fundamental research question in this field is to determine necessary and sufficient conditions for a simple game to be a weighted...     

Estimation of the Proportion of Defective Units by Using Group Testing Under the Existence of a Threshold of Detection

Group testing procedures, in which groups containing several units are tested without testing each unit, are widely used as cost-effective procedures in estimating the proportion of defective units in a population. A problem arises when we apply these procedures to the detection of genetically modified organisms (GMOs), because the analytical instrument for detecting GMOs has a threshold of detection. If the group size (i.e., the number of units within a group) is large, the GMOs in a group are not detected due to the dilution even if the group contains one unit of GMOs. Thus, most people conventionally use a small group size (which we call conventional group size) so that they can surely detect the existence of defective units if at least one unit of GMOs is included in the group. However, we show that we can estimate the proportion of defective units for any group size even if a threshold of detection exists; the estimate of the proportion of defective units is easily obtained by using functions implemented in a spreadsheet. Then, we show that the conventional group size is not always optimal in controlling a consumer's risk, because such a group size requires a larger number of groups for testing.     

A new quantitative method for assessing sleepiness: The alpha attenuation test

Abstract

Sleepiness interferes with the ability of night-workers and shiftworkers to safely and effectively perform their jobs, and has been increasingly recognized as a major cause of industrial and transportation accidents. Current methods for the assessment of physiological sleepiness levels, such as the Multiple Sleep Latency Test (MSLT) have several limitations and are particularly impractical in field or occupational studies. In this study, the effectiveness of the Alpha Attenuation Test (AAT) for the quantification of sleepiness has been evaluated and compared to the MSLT during a 40-h sleep deprivation protocol. The AAT, a 12-min eye closed/open protocol, is a quantitative method based on the fact that EEG alpha (8-12 Hz) activity tends to increase with eyes open as individuals get sleepier, while it decreases with eyes closed. In this validation study, the AAT proved to be a sensitive measure of sleepiness induced by sleep deprivation, and it also correlated well with the MSLT. Relative to the MSLT, the AAT has the advantages of being objective, minimally intrusive, and more practical especially in industrial or field studies.     

Income earning opportunity and work performance affect donating behavior: Evidence from dictator game experiments

Using dictator game experiments, the authors investigate the effect on donation of the dictator and/or recipient working prior to the dictator donating. We focus on two issues that previous studies have not considered. First, we examine the impact on donating behavior of a difference in endowment caused by the dictator's work performance. Second, we explore donation behavior when the recipient's work does not yield income or affect the dictator's endowment, but the recipient's work performance is made known to the dictator. Experimental results indicate that donating behavior is affected not only by the dictator working, but also by the recipient working. In addition, donating behavior is affected by income level, as determined by the dictator's work performance, and is influenced by the recipient's work performance, two findings not previously reported.     

A Fake Smile Thwarts Cheater Detection

People can discriminate cheaters from cooperators on the basis of negative facial expressions. However, such cheater detection is far from perfect in real-world situations. Therefore, it is possible that cheaters have the ability to disguise negative emotional expressions that signal their uncooperative attitude. To test this possibility, emotional intensity and trustworthiness were evaluated for facial photographs of cheaters and cooperators defined by scores in an economic game. The facial photographs had either posed happy or angry expressions. The angry expressions of cheaters were rated angrier and less trustworthy than those of cooperators. On the other hand, happy expressions of cheaters were higher in emotional intensity but comparable to those of cooperators in trustworthiness. These results suggest that cheater detection based on the processing of negative facial expressions can be thwarted by a posed or fake smile, which cheaters put on with higher intensity than cooperators.     

Has Livability of Japan Gotten Better for 1956–1990?: a Dea Approach

This paper presents an approach for time-series livability assessment using DEA (Data Envelopment Analysis), a mathematical programming technique for measuring the relative efficiency of DMUs (Decision Making Units) with multiple inputs and multiple outputs. Regarding each year as a separate DMU in DEA, and replacing the inputs and the outputs with negative and positive social indicators respectively, we evaluate Japan's livability for the period 1956–1990. Results of the analysis using eight social indicators identify 20 DEA livable years out of the 35 and find eight best-balanced years. It is concluded that DEA, which enables non-uniform, multi-dimensional and relative evaluation, can be a valuable analytic tool in quality-of-life research as well. This revised version was published online in August 2006 with corrections to the Cover Date.     

Assessing the prediction accuracy of cure in the Cox proportional hazards cure model: an application to breast cancer data

A cure rate model is a survival model incorporating the cure rate with the assumption that the population contains both uncured and cured individuals. It is a powerful statistical tool for prognostic studies, especially in cancer. The cure rate is important for making treatment decisions in clinical practice. The proportional hazards (PH) cure model can predict the cure rate for each patient. This contains a logistic regression component for the cure rate and a Cox regression component to estimate the hazard for uncured patients. A measure for quantifying the predictive accuracy of the cure rate estimated by the Cox PH cure model is required, as there has been a lack of previous research in this area. We used the Cox PH cure model for the breast cancer data; however, the area under the receiver operating characteristic curve (AUC) could not be estimated because many patients were censored. In this study, we used imputation‐based AUCs to assess the predictive accuracy of the cure rate from the PH cure model. We examined the precision of these AUCs using simulation studies. The results demonstrated that the imputation‐based AUCs were estimable and their biases were negligibly small in many cases, although ordinary AUC could not be estimated. Additionally, we introduced the bias‐correction method of imputation‐based AUCs and found that the bias‐corrected estimate successfully compensated the overestimation in the simulation studies. We also illustrated the estimation of the imputation‐based AUCs using breast cancer data. Copyright © 2014 John Wiley & Sons, Ltd.     

Can I Trust You? Laterality of Facial Trustworthiness in an Economic Game

People tend to turn their left or right cheek to express or conceal emotions, respectively. We examined the lateral posing bias for displaying trustworthiness during a trust game in which participants and their virtual partners cooperated or did not cooperate with their counterparts to earn a monetary reward. Right-handed participants (N = 81) were asked to pose for a photograph and then play the trust game. Participants showed an overall left posing bias (i.e., showing their left cheek to the camera). The left cheek bias was more stable for participants that cooperated very little in the trust game (non-cooperators) than for those that cooperated a lot (cooperators). In the rating experiment (N = 28 and 25), non-cooperators showing their left cheek were rated equally as trustworthy as cooperators. On the other hand, non-cooperators who showed their right cheek were rated as less trustworthy than cooperators. These results suggest that non-cooperators intuitively use the left hemiface to exploit others in social interactions.