The symmetric and asymmetric Choquet integrals on finite spaces for decision making

In this paper, we give a mathematical analysis of symmetric and asymmetric Choquet integrals in the view of decision making in a finite setting. These integrals present two ways of dealing with negative integrands. The analysis is done with the aid of the Möbius and interaction transforms, this last one having an interesting interpretation in multicriteria decision making (MCDM). The last part of the paper shows the application of these two integrals in MCDM.     

Social choice with analytic preferences

Arrow's axioms for social welfare functions are shown to be inconsistent when the set of alternatives is the nonnegative orthant in a multidimensional Euclidean space and preferences are assumed to be either the set of analytic classical economic preferences or the set of Euclidean spatial preferences. When either of these preference domains is combined with an agenda domain consisting of compact sets with nonempty interiors, strengthened versions of the Arrovian social choice correspondence axioms are shown to be consistent. To help establish the economic possibility theorem, an ordinal version of the Analytic Continuation Principle is developed. Received: 4 July 2000/Accepted: 2 April 2001     

The free circulation of Individuals between the European Community member states: The practical implications for social security schemes

Freedom of movement in an integrated European Economic Area created the need to coordinate social security legislations by means of complex regulations. Improving their application calls for innovative solutions based on the experience of ISSA member institutions, ILO standards and the initiative of non-governmental organizations. These solutions are also of interest to institutions in states — even non-European states — linked to the Community by bilateral or multilateral conventions. The main objective is to simplify and speed up administrative procedures, notably for the award of pensions to migrants, given the desirability of identifying them and reconstructing their working careers at the earliest opportunity. Teleprocessing must gradually replace the international circulation of forms, facilitating in particular the provision of medical care during a temporary stay. Recipients'effective access to benefits can also be improved through the personal intervention of liaison offices, the use of migrants'own language and the aid of social services.     

The Development of Object Construction From Infancy Through Toddlerhood

Early in development, children explore and combine objects in increasingly complex ways. One manual skill, object construction, represents a major shift in how objects are explored relative to other objects. Despite recent connections with cognitive functioning such as spatial skills, the development of object construction ability has rarely been studied and its trajectory has not been adequately described. The purpose of this study was to describe the development of three types of object construction (stacking, nesting, and affixing) across 5 monthly infant visits and 7 monthly toddler visits using a longitudinal design and a large sample size. Infants (10–14 months, n = 131) and toddlers drawn from the infant sample (18–24 months, n = 65) were given sets of age‐appropriate toys each of which elicited at least one type of constructive play. We described success at different construction tasks and identified trends for construction skill for infant and toddler development using multilevel modeling. We found that each of the three construction actions developed in unique ways across the 10‐ to 24‐month period. Infant construction skill predicted the development of toddler skill, but toddler construction skill diverged from infant trajectories. We discuss the role of combination strategies in the development of object construction skill and how object construction could be related to other domains of development.     

Asymptotic behaviour of binned kernel density estimators for locally non-stationary random fields

We investigate the asymptotic behaviour of binned kernel density estimators for dependent and locally non-stationary random fields converging to stationary random fields. We focus on the study of the bias and the asymptotic normality of the estimators. A simulation experiment conducted shows that both the kernel density estimator and the binned kernel density estimator have the same behavior and both estimate accurately the true density when the number of fields increases. We apply our results to the 2002 incidence rates of tuberculosis in the departments of France.     

Correlation and variable importance in random forests

This paper is about variable selection with the random forests algorithm in presence of correlated predictors. In high-dimensional regression or classification frameworks, variable selection is a difficult task, that becomes even more challenging in the presence of highly correlated predictors. Firstly we provide a theoretical study of the permutation importance measure for an additive regression model. This allows us to describe how the correlation between predictors impacts the permutation importance. Our results motivate the use of the recursive feature elimination (RFE) algorithm for variable selection in this context. This algorithm recursively eliminates the variables using permutation importance measure as a ranking criterion. Next various simulation experiments illustrate the efficiency of the RFE algorithm for selecting a small number of variables together with a good prediction error. Finally, this selection algorithm is tested on the Landsat Satellite data from the UCI Machine Learning Repository.     

Adolescents,Online Marketing and Privacy: Predicting Adolescents’ Willingness to Disclose Personal Information for Marketing Purposes

The present study aims at exploring which factors predict the willingness of adolescents to disclose personal information in response to online marketing requests. Our analyses show that especially privacy concerns and perceived benefits explain a considerable portion of variance in both willingness to disclose profile data (e.g. age, hobbies, favourite products) and contact data (e.g. phone number, e‐mail address, home address). An interesting interrelationship was found between profile data and contact data disclosure. Contrary to our expectations, parental mediation strategies were only a weak predictor of teenagers’ willingness to disclose contact information. Policy implications that emerge from the central findings of this study are discussed.     

Interplay between Friends' Aggression and Friendship Quality in the Development of Child Aggression during the Early School Years

The aim of this study was to investigate the unique and combined role of friendship quality and friends' aggression in regard to the persistence of young children's physical aggression from kindergarten to grade 2. The sample included 1555 children (808 girls) assessed annually using teacher ratings. Two theoretical perspectives (i.e., the social learning and the social bonding perspectives) served as frameworks to guide the analyses and interpret the results. In line with the social learning perspective, friends' aggression was related to a significant increase in children's physical aggression. However, in line with the social bonding perspective, good friendship quality played both a compensatory and a protective role, by, respectively, reducing children's initial level of physical aggression and by mitigating, albeit marginally, the associations between friends' and children's physical aggression. These results suggest that fostering a positive relationship between friends in the early school years may decrease physical aggression even if the friends are aggressive.     

Parents’ perspectives of social support and social cohesion in urban contexts of diversity

Although provisions for young children are increasingly considered as ideal places to foster an inclusive and socially just society by embracing issues of social support and social cohesion, there is no in-depth understanding of the role these provisions can play in enabling supportive and cohesive encounters in contexts of diversity. Even more striking is the absence of parents’ voices in this discussion. Based on an analysis of qualitative interviews with 18 parents who use childcare services in urban contexts of diversity, our findings show the relevance of ephemeral contacts with diverse people that could offer bridging opportunities in terms of social connectedness to familiarise within diversity while decoding the other in urban contexts of diversity. However, neither bonding nor bridging contacts appear as self-evident. Our research shows that the role of childcare services might be vital in creating light and temporal communities as the prerequisite for social cohesion to flourish, in both individual as well as collective dimensions.     

A Bitcoin-inspired infinite-server model with a random fluid limit

The synchronization process inherent to the Bitcoin network gives rise to an infinite-server model with the unusual feature that customers interact. Among the closed-form characteristics that we derive for this model is the busy period distribution which, counterintuitively, does not depend on the arrival rate. We explain this by exploiting the equivalence between two specific service disciplines, which is also used to derive the model’s stationary distribution. Next to these closed-form results, the second major contribution concerns an asymptotic result: a fluid limit in the presence of service delays. Since fluid limits arise under scalings of the law-of-large-numbers type, they are usually deterministic, but in the setting of the model discussed in this paper the fluid limit is random (more specifically, of growth-collapse type).