A Stochastic Model for Car-Sharing Systems

Vehicle-sharing systems are becoming important for urban transportation. In these systems, users arrive at a station, pick up a vehicle, use it for a while and then return it to another station of their choice. Depending on the type of system, there might be a possibility to book vehicles before picking-up and/or a parking space at the chosen arrival station. Each station has a finite capacity and cannot host more vehicles and reserved parking spaces than its capacity. We propose a stochastic model for an homogeneous car-sharing system with possibility to reserve a parking space at the arrival station when picking-up a car. We compute the performance of the system and the optimal fleet size according to a specific metric. It differs from a similar model for bike-sharing systems because of reservation that induces complexity, especially when traffic increases

L’évolution de la monoparentalité féminine dans différentes régions du Québec, 1971-1981

Contrairement à la monoparentalité passée, la « nouvelle » monoparentalité est avant tout le résultat des ruptures volontaires d’union et des naissances hors mariage; elle affecte de façon croissante majoritairement des femmes, et touche une population de plus en plus jeune, tant chez les parents que chez les enfants. Après une analyse de l’évolution de l’intensité et de la structure par âge des familles monoparentales à chef féminin, cet article examine le profil socio-économique de celles-ci, et plus particulièrement le taux d’activité des femmes chefs de famille monoparentale, le revenu moyen et les conditions de logement, et ce pour les diverses régions métropolitaines du Québec.Contrarily to the past, the new single parent family is in most cases the result of a voluntary disruption of the household, or of a birth outside marriage; its head is mostly—and increasingly—the mother; and it concerns an increasingly younger population, among parents as well as children. After analysing the evolution of the level and age structure of female single parent families in Quebec, the authors describe the socio-economic profile of these families (labor force participation rate, mean income and housing), for each of the metropolitan regions of Quebec.Contrariamente a la familia unipaterna de antes, la nueva familia unipaterna es ante todo el resultado de las rupturas voluntarias de uniones y de los nacimientos fuera del casamiento; ella afecta en forma creciente y en su mayoria a las mujeres y toca una población cada vez más joven tanto en lo que atane a los padres como a los chicos. Después de un análisis de la evolución de la intensidad y de la estructura segun la edad de las familias unipaternas formadas por una mujer, este artículo examina el perfil socio-económico de ellas y más particularmente la taza de actividad de las mujeres, jefes de familia unipaterna, el ingreso promedio y las condiciones de vivienda y ésto para las distintas regiones metropolitanas de Québec

An entropy penalized approach for stochastic control problems. Complete version

In this paper, we propose an alternative technique to dynamic programming for solving stochastic control problems. We consider a weak formulation that is written as an optimization (minimization) problem on the space of probabilities. We then propose a regularized version of this problem obtained by splitting the minimization variables and penalizing the entropy between the two probabilities to be optimized. We show that the regularized problem provides a good approximation of the original problem when the weight of the entropy regularization term is large enough. Moreover, the regularized problem has the advantage of giving rise to optimization problems that are easy to solve in each of the two optimization variables when the other is fixed. We take advantage of this property to propose an alternating optimization algorithm whose convergence to the infimum of the regularized problem is shown. The relevance of this approach is illustrated by solving a high-dimensional stochastic control problem aimed at controlling consumption in electrical systems

Disparités régionales dans la propension des Canadiennes à vivre en famille recomposée

Cette recherche situe l'importance des familles recomposées dans quatre régions canadiennes (Atlantique, Québec, Ontario et Ouest) à partir des données de deux enquêtes rétrospectives sur la famille menées en 1984 et en 1990. La première partie de l'analyse fournit une estimation de l'ampleur du phénomène dans les quatre régions retenues, au moment où les deux enquêtes ont été réalisées. La seconde partie examine dans quelle mesure les modalités d'entrée dans le premier épisode en famille recomposée, vécu par les répondantes rejointes en 1990, diffèrent d'une région à l'autre, et de quelle façon la propension des femmes à connaître cette expérience s'est modifiée au fil des générations; elle fournit également des informations sur la durée et le type d'issue de ces épisodes familiaux. Plus globalement, l'analyse longitudinale des recompositions familiales permet de dégager les grands traits des modèles de constitution familiale existants dans les quatre régions étudiées et d'esquisser l'évolution attendue de ce type de famille.This study examines the relative distribution of step-families across four Canadian regions (Atlantic Provinces, Québec, Ontario and the West), using data from two retrospective surveys on the family conducted in 1984 and 1990. The first part of the analysis measures the propensity of women to live in step-families in the four regions at the time of the two surveys. Based upon the 1990 survey, the second part examines the extent to which the methods of forming a step-family differ from one region to another, and the manner in which the propensities of women to experience this situation for the first time has changed over generations; it also provides information on the length and the result of these family episodes. More generally, the longitudinal analysis of family recomposition enables one to identify the major trends in family composition across the four regions studied, and to sketch the expected evolution of step-families in these regions

Dynamique et déterminants de la participation des femmes au marché du travail après la naissance d’un enfant au Canada

Cette étude dresse un portrait du calendrier et de l’intensité de l’entrée ou du retour dans le marché du travail des femmes après la naissance d’un enfant au Canada, et des facteurs associés aux variations du rythme d’entrée ou de retour. Les comportements des mères ayant donné naissance à un enfant entre 1994 et 2003 sont analysés par la méthode d’analyse des transitions, à partir des données de l’Enquête sur la dynamique du travail et du revenu (EDTR). Cette étude montre d’abord que les responsabilités professionnelles et parentales des Canadiennes sont rapidement combinées après la naissance d’un enfant. Elle met également en évidence la polarisation nette du comportement professionnel des mères en fonction notamment de leur situation familiale et des caractéristiques de leur participation au marché du travail avant la naissance de l’enfant. Par ailleurs, l’analyse fait ressortir que l’effet de certaines variables varie différemment selon que les mères effectuent un retour sur le marché du travail à plein temps ou à temps partiel. Ces résultats illustrent la pertinence de prendre en compte le régime d’emploi dans l’analyse du comportement professionnel des femmes après l’arrivée d’un enfant, de manière à cerner plus finement les stratégies d’ajustement professionnel que les mères adoptent au fil du temps en fonction de leurs responsabilités professionnelles et familiales.This study looks at the timing and intensity of women’s entry or return to work after childbirth in Canada, and at factors associated with variations in the rate at which they enter or return. The behavior of mothers who gave birth between 1994 and 2003 are analysed using the event history analysis method, based on data from Survey on Labor and Income Dynamics (SLID). This study shows at first that the professional and parental responsibilities of the women are quickly organized after the birth of a child. It also brings to light the net polarization of the professional behavior of the mothers in function in particular of their family situation and characteristics of their participation in the labor market before the birth of the child. Besides, the analysis also highlights that the effect of certain variables varies differently as the mothers make a return in the full-time or part-time labor market. These results illustrate the relevance of take into account these alternatives in the analysis of the professional behaviour of the women after the birth of a child, so as to encircle more finely the strategies of professional adjustment which the mothers adopt over the life course according to their professional and family responsibilities

Non-standard work schedules, gender, and parental stress

Support for this research was provided by the Social Sciences and Humanities Research Council (SSHRC) and the McGill Canada Research Chair on Social Statistics and Family Change. The analysis was conducted at the Quebec Interuniversity Centre for Social Statistics which is part of the Canadian Research Data Centre Network (CRDCN). The services and activities provided by the QICSS are made possible by the financial or in-kind support of SSHRC, CIHR, CFI, Statistics Canada, FRQSC and Quebec universities. In addition, Dana Hamplova‟s work was supported by financial support from the Czech Science Foundation (Grant GA14-15008S)Background Working non-standard hours changes the temporal structure of family life, constraining the time that family members spend with one another and threatening individuals‟ well-being. However, the empirical research on the link between stress and non-standard schedules has provided mixed results. Some studies have indicated that working non-standard hours is harmful whereas others have suggested that working atypical hours might facilitate the balance between family and work. Moreover, there is some evidence that the association between stress and non-standard employment has different implications for men and women. Objective This paper examines the association between non-standard work schedules and stress among dual-earner couples with children. Two research questions are addressed. First, do predictability of the schedule and time flexibility moderate the link between non-standard work hours and stress? Second, do non-standard schedules affect men‟s and women‟s perceptions of stress differently? Methods We use a sample of 1,932 working parents from the Canadian 2010 General Social Survey, which includes a time-use diary. A sequential logit regression analysis stratified by gender is employed to model two types of result. First, we estimate the odds of being stressed versus not being stressed. Second, for all respondents feeling stressed, we estimate the odds of experiencing high levels versus moderate levels of stress. Results Our analysis shows that the link between non-standard working hours and perceived stress differs between mothers and fathers. First, fathers with non-standard schedules appear more likely to experience stress than those working standard hours, although the results are not significant. Among mothers, having a non-standard schedule is associated with a significantly lower risk of experiencing stress. Second, the analysis focusing on the mediating role of flexibility and predictability indicates that predictability is more important than flexibility. Workers with non-standard predictable schedules exhibit a lower risk of being stressed than those with non-standard unpredictable hours. Work flexibility does not seem to bring any additional advantage to women. However, it is linked to higher odds of being stressed for fathers, particularly among those having non-standard schedules

Changements dans la dynamique de la participation des hommes et des femmes au marché du travail au Canada

Cette étude porte sur l’évolution de la dynamique de la participation des individus au marché du travail au Canada. Les mouvements d’insertion, d’interruption et de réinsertion dans l’emploi que les générations d’hommes et de femmes nés entre 1937 et 1986 connaissent au long de leur vie sont analysés séparément par la méthode des tables d’extinctions multiples, appliquée aux données rétrospectives de l’Enquête sociale générale de 2001 sur la famille.This study looks at changes in the individual’s labor force participation in Canada. For cohorts born between 1937 and 1986, moves into and out of the labor market of men and women are analysed separately using the multiple decrement life tables method applied to the retrospective data of the 2001 General Social Survey on family

Familles et réseau familial extra-résidentiel : une réflexion sur les limites de la définition statistique de la famille

Monoparentalité et recomposition familiale font dorénavant partie de la vie familiale. Dans ce contexte, souvent les parents séparés ne vivent plus au quotidien avec leurs enfants, sans que ne s’éteignent les droits et les obligations qui les unissent. Le maintien de ces relations parent-enfants met en cause la pertinence de la définition statistique de la famille fondée sur la corésidence. Les résultats d’une analyse fondée sur l’Enquête sociale générale de 2001 réalisée par Statistique Canada montrent que le nombre de ménages qui, à un moment ou l’autre, accueillent des enfants de moins de 18 ans augmente de 13 %, lorsque l’on tient compte du réseau familial extra-résidentiel. La vérification de l’existence de relations concrètes entre parents et enfants qui ne vivent pas ensemble rencontre cependant des embûches liées aux perceptions divergentes des parents selon qu’ils habitent ou non avec leurs enfants, ainsi qu’aux difficultés associées à la représentativité des échantillons des parents non résidants.Lone-parenthood and step-parenthood are now part of contemporary family life. In this context, separated parents often do not live on a daily basis with their children, while still assuming rights and responsibilities towards them. The maintenance of these parent-children relationships questions the relevance of the traditional definition of the family based on co-residence. An analysis of the 2001 General Social Survey conducted by Statistics Canada shows a 13 % increase in the number of households that include children aged less than 18 years, when taking into account the extra-residential family network. Verifying the existence of concrete relationships between family members who are not living together proves, however, to be difficult, because of the divergent perceptions of parents depending on whether or not they live with their children, and of the problems associated with reaching a representative sample of non-residing parents