Measuring power and satisfaction in societies with opinion leaders: an axiomatization

Opinion leaders are actors who have some power over their followers as they are able to influence their followers’ choice of action in certain instances. In van den Brink et al. (Homo Oeconomicus 28:161–185, 2011) we proposed a two-action model for societies with opinion leaders. We introduced a power and a satisfaction score and studied some common properties. In this paper we strengthen two of these properties and present two further properties, which allows us to axiomatize both scores for the case that followers require unanimous action inclinations of their opinion leaders to follow them independently from their own action inclinations.     

Refined solution to upper-bound problem for the expectations of order statistics from decreasing density on the average distributions

Rychlik [Metrika 77, 539–557, 2014] described sharp upper negative bounds for the expectations of low-rank order statistics, centered about the population mean and measured in the mean absolute deviation from the mean units, for the i.i.d. sequences with common distribution possessing decreasing density function on the average. The bounds coincide with the negatives of maximal values of complicated functions on the unit interval. Here, we provide more precise solutions to the maximization problems.     

Lower bounds on the expectations of upper record values

For infinite sequences of independent random variables with identical continuous distributions, we establish optimal lower bounds on the deviations of the expectations of record values from population means in units generated by the central absolute moments of various orders. The bounds are non-negative for the classic record values, and non-positive for the other kth records with k?2. We also provide analogous bounds for the record increments.     

Properties of the Cox–Stuart Test for Trend in Application to Hydrological Series: The Simulation Study

The size and power properties of the Cox–Stuart test for detection of a monotonic deterministic trend in hydrological time series are analyzed using the Monte Carlo method. The influence of distribution properties, lengths of series, and trend slopes is studied. Results indicate good size in all cases. The power is high for: length over 60 and strong trend slope, low or medium variation, and medium slope. The power declines if slope and length decrease and if variability increases. The properties are better for skewed distributions than for symmetrical. The test is slightly weaker in comparison to the Mann–Kendall test.     

Older age and a higher EHRA score allow higher levels of frailty syndrome to be predicted in patients with atrial fibrillation

Background: There is no research that evaluates the relationship between the severity of the symptoms of atrial fibrillation (AF), the presence of frailty syndrome and acceptance of the illness.

Methods: The study included 132 patients aged 72.7?±?6.73 with diagnosed AF. The severity of the symptoms of AF was determined according to European Heart Rhythm Association (EHRA) guidelines, frailty syndrome was assessed using the Tilburg frailty indicator (TFI) and the acceptance of the illness was assessed using the acceptance of illness scale (AIS). A standard statistical comparison and multiple regression analysis using the stepwise method were performed.

Results: In patients with AF, frailty was 5.31?±?2.69 (TFI). Frailty syndrome was diagnosed in 59.8% of the AF patients who had a score of 7.17?±?1.72. A higher level of EHRA score was connected with a smaller degree of the acceptance of the illness p?=?0.0000. The multiple regression model indicated that age (p?=?0.0009) and the severity of the symptoms (p?=?0.0001) are important predictors of frailty syndrome.

Conclusions: There is a relationship between the presence of frailty syndrome and the intensity of the symptoms and the acceptance of AF. Age and the EHRA score permitted higher levels of frailty syndrome to be predicted.     

Physical activity of middle-age adults aged 50–65 years in view of health recommendations

The objective of the study was to assess the level of habitual physical activity, mainly its frequency and duration, of middle-age adults aged 50–65 years in a typical week of their life in comparison to the level of these parameters recommended for health benefits. The study carried out in the Upper Silesia region in Poland in May 2010 included 456 deliberately selected subjects (234 women and 222 men) aged 50–65 years. Numeric data were collected by diagnostic survey method using the short version of IPAQ. The surveyed men were characterized by higher level of physical activity than the surveyed women (longer duration and higher frequency) (p?p?相似文献   

Measuring the innovation ability of Taiwan's food industry using DEA

The ability of companies to meet consumer expectations depends greatly on their ability to innovate and deliver new products at competitive prices. This research study is designed to determine the key innovation factors of Taiwan's food industry and draws on a questionnaire to collect data about its innovativeness. Data Envelopment Analysis (DEA) revealed the most and the least innovative products among our sample group. Strategies of how to improve the products’ innovativeness are proposed. Our study contributes to the food industry in Taiwan by determining a set of factors for innovativeness, presenting outstanding examples from the researched industry that can be used as a benchmark by other food companies or as a reference for other industries in other countries. Finally, innovativeness improvement strategies for Taiwan's food industry are proposed, taking company size into consideration.     

A model of influence with an ordered set of possible actions

In the article, a yes–no model of influence is generalized to a multi-choice framework. We introduce and study the weighted influence indices of a coalition on a player in a social network where the players have an ordered set of possible actions. Each player has an inclination to choose one of the actions. Due to the mutual influence among players, the final decision of each player may be different from his original inclination. In a particular case, the decision of the player is closer to the inclination of the influencing coalition than his inclination was, i.e., the distance between the inclinations of the player and of the coalition is greater than the distance between the decision of the player and the inclination of the coalition in question. The weighted influence index which captures such a case is called the weighted positive influence index. We also consider the weighted negative influence index where the final decision of the player goes farther away from the inclination of the coalition. We consider several influence functions defined in the generalized model of influence and study their properties. The concept of a follower of a given coalition and its particular case, a perfect follower, are defined. The properties of the set of followers are analyzed.     

Variability in the Inter‐group Attitudes of White Children: What We Can Learn from Their Ethnic Identity Labels

The current study examined the ethnic identity of White (N = 120), Latino (N = 87), and African‐American (N = 65) children and early adolescents (aged = 9–14 years), with an emphasis on whether the specific ethnic label White children used to describe themselves might reflect differences in their inter‐group attitudes and whether those differences mirror group differences between White children and children in ethnic minority groups. Results indicated that White children who identified with a minority label (i.e., White biracial, hyphenated American, ethnic/cultural/religious label) had more positive ethnic identities, were more aware of discrimination, and were less likely to show biases in their perceived similarity to in‐group and out‐group peers than youth who identified as White or American. In many instances, White children who identified with a minority label did not differ from ethnic minority youth. In addition, although all participants were more positive about their ethnic in‐group than out‐groups, children who identified their ethnicity as American were less positive about out‐groups relative to other children. Taken together, the findings indicate that children's self‐chosen ethnic identity is as important as their ascribed ethnic or racial identity in predicting their inter‐group attitudes.