Dynamic vehicle routing problems: Three decades and counting

Since the late 70s, much research activity has taken place on the class of dynamic vehicle routing problems (DVRP), with the time period after year 2000 witnessing a real explosion in related papers. Our paper sheds more light into work in this area over more than 3 decades by developing a taxonomy of DVRP papers according to 11 criteria. These are (1) type of problem, (2) logistical context, (3) transportation mode, (4) objective function, (5) fleet size, (6) time constraints, (7) vehicle capacity constraints, (8) the ability to reject customers, (9) the nature of the dynamic element, (10) the nature of the stochasticity (if any), and (11) the solution method. We comment on technological vis-à-vis methodological advances for this class of problems and suggest directions for further research. The latter include alternative objective functions, vehicle speed as decision variable, more explicit linkages of methodology to technological advances and analysis of worst case or average case performance of heuristics.© 2015 Wiley Periodicals, Inc

Evaluation of nitrogen fertilizing value of composted household solid waste under greenhouse conditions

Accumulation of municipal solid wastes, such as household solid waste, can be rated as a harmful, if not critical, pollution problem. However, if these wastes can be composted and the end product used as soil organic amendment or fertilizer, this may represent one of the alternatives for achieving the goal of ensuring integrated and sustainable waste management. The objective of the present work is to evaluate the nitrogen fertilizing value of household solid waste compost in two soils of Morocco with contrasting properties: a sandy soil and a loamy-clay soil. The compost used in this study was prepared by aerobic biodegradation using the organic fraction after its separation from the non-compostable materials. A study of nitrogen availability of the compost was carried out in a Soil – Compost – Crop system under greenhouse conditions using lettuce as a test crop. Four increasing compost rates of 0, 10, 20 and 30 tons/ha were applied to the soils. The recommended mineral fertilizer rate by the Agricultural Extension Service for lettuce and its half values constituted additional treatments. The results show a high stock of mineral nitrogen in the loamy-clay soil before crop installation. Unlike the loamy-clay soil, the sandy soil generated a better yield increase and a better response to mineral fertilizers. The effect of compost rate on nitrogen mineralization was significant in the two studied soils. The quantities of mineralized nitrogen of the compost varied between 15 and 24% of the compost total nitrogen applied to the sandy and the loamy-clay soils during the lettuce growing season. Therefore the use of household solid waste compost as soil amendment constitutes a beneficial alternative in Mediterranean soils because it permits the generation of a high nitrogen fertilizing value

" LIVING TOGETHER " PREVENTION WORKSHOPS ON RADICALIZATION IN PRISON SETTING

International audienceWe aim to introduce a field action set up in the prison field following the Paris attacks (07/01/2015) in order to create a talking and thinking space for new arrivals in jail. This action, based on prevention workshops (N=7), has been hosted each time by a probation officer and a psychologist, allowing about forty incarcerated men to think about each one's place as a citizen. We used intergroup relations framework, specifically of social categorization metatheory (Abrams & Hogg, 2004; Tajfel & Turner, 1979, 1986; Turner et al., 1987), supplemented by theory of social partitions (Castel & Lacassagne, 2011, 2015). The methodology is based on empathy in relationship, identification and deconstruction of stereotypes and the need to think about collective beliefs and co-construction concept of "republican secularism". This is made through the solicitation of participants' personal, social and collective identities. Resorting to a mixed methodology, integrating support and moments contrasting with commonly used ones in workshops and talking groups, allowed to break habits underlying social roles. The failure to mention requirement of action and imprisonment reason allowed participants to put across a definition of identity out of their reality of incarcerated individuals. Joint coordination with outside staff of prison system ensured speaker's as well as participants' participation, which favoured trust and dialogue (participants' private lives were discussed and gave rise to convivial moments). Each workshop took place over a period of three half-days: a) Creation of framework (for the action) and first interaction on the problems of relationships (inside/outside jail); brainstorming about citizenship and its contexts; exchange about religious beliefs and republican values, especially secularism. Main thematic areas on which the participants worked, have been classified under three types of relationships: personal and interpersonal, intergroup, and institutional and societal. These types of elations led to relations improvement strategies: a/ significance of free thinking and taking ownership of decisions b/ usefulness of forbearance and of daily negotiation and accepting that one may not be always right, c/ questioning empathy and republican equality, resonating with Syrian migrants and d/ linking founding principles of religion and official documents of the Republic, leading to think about religious liberty and understanding acts of violence as a result of a radical interpretation and not as a specific religious belief. This action has been favourably assessed and welcomed, either by funders or by participants, leading to a renewal in 2016. Extending the target audience not only aids improvement but also intervention and research programs, analysing relations between prisoner categories (foreigners/natives)