A guided search non-dominated sorting genetic algorithm for the multi-objective university course timetabling problem

Copyright @ Springer-Verlag Berlin Heidelberg 2011.The university course timetabling problem is a typical combinatorial optimization problem. This paper tackles the multi-objective university course timetabling problem (MOUCTP) and proposes a guided search non-dominated sorting genetic algorithm to solve the MOUCTP. The proposed algorithm integrates a guided search technique, which uses a memory to store useful information extracted from previous good solutions to guide the generation of new solutions, and two local search schemes to enhance its performance for the MOUCTP. The experimental results based on a set of test problems show that the proposed algorithm is efficient for solving the MOUCTP

Modelling the Relationship between Travel Behaviour and Social Disadvantage

The purpose of this paper is to model the travel behaviour of socially disadvantaged population segments in the United Kingdom (UK) using the data from the UK National Travel Survey 2002-2010. This was achieved by introducing additional socioeconomic variables into a standard national-level trip end model (TEM) and using purpose-based analysis of the travel behaviours of certain key socially disadvantaged groups. Specifically the paper aims to explore how far the economic and social disadvantages of these individuals can be used to explain the inequalities in their travel behaviours. The models demonstrated important differences in travel behaviours according to household income, presence of children in the household, possession of a driver’s license and belonging to a vulnerable population group, such as being disabled, non-white or having single parent household status. In the case of household income, there was a non-linear relationship with trip frequency and a linear one with distance travelled. The recent economic austerity measures that have been introduced in the UK and many other European countries have led to major cutbacks in public subsidies for socially necessary transport services, making results such as these increasingly important for transport policy decision-making. The results indicate that the inclusion of additional socioeconomic variables is useful for identifying significant differences in the trip patterns and distances travelled by low-income

Three-Loop Superfiniteness of N=8 Supergravity

We construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments, render its degree of divergence in D dimensions to be no worse than that of N=4 super-Yang-Mills theory -- a finite theory in four dimensions. Similar cancellations can be identified at all loop orders in certain unitarity cuts, suggesting that N=8 supergravity may be a perturbatively finite theory of quantum gravity.Comment: 5 pages, 4 figures. In v2 references and minor clarifications adde

Local investigation of femtosecond laser induced dynamics of water nanoclusters on Cu(111)

We explore the dynamics of low temperature interfacial water nanoclusters on Cu(111) by femtosecond-laser excitation, scanning tunneling microscopy and density functional theory. Laser illumination can be used to induce single molecules to diffuse within water clusters and across the surface, breaking and reforming hydrogen bonds. A linear diffusion probability with laser fluence is observed up to 0.6 J/m2 and we suggest that diffusion is initiated by hot electron attachment and detachment processes. The density functional calculations shed light on the detailed molecular mechanism for water diffusion that is determined by the local structure of the water clusters

Exploring agricultural land-use and childhood malaria associations in sub-Saharan Africa

Agriculture in Africa is rapidly expanding but with this comes potential disbenefits for the environment and human health. Here, we retrospectively assess whether childhood malaria in sub-Saharan Africa varies across differing agricultural land uses after controlling for socio-economic and environmental confounders. Using a multi-model inference hierarchical modelling framework, we found that rainfed cropland was associated with increased malaria in rural (OR 1.10, CI 1.03 – 1.18) but not urban areas, while irrigated or post flooding cropland was associated with malaria in urban (OR 1.09, CI 1.00 – 1.18) but not rural areas. In contrast, although malaria was associated with complete forest cover (OR 1.35, CI 1.24 – 1.47), the presence of natural vegetation in agricultural lands potentially reduces the odds of malaria depending on rural-urban context. In contrast, no associations with malaria were observed for natural vegetation interspersed with cropland (veg-dominant mosaic). Agricultural expansion through rainfed or irrigated cropland may increase childhood malaria in rural or urban contexts in sub-Saharan Africa but retaining some natural vegetation within croplands could help mitigate this risk and provide environmental co-benefits

Neutron and proton spectra from the decay of Λ\Lambda hypernuclei

We have determined the spectra of neutrons and protons following the decay of $\Lambda$ hypernuclei through the one- and two-nucleon induced mechanisms. The momentum distributions of the primary nucleons are calculated and a Monte Carlo simulation is used to account for final state interactions. From the spectra we calculate the number of neutrons ($N_n$) and protons ($N_p$) per $\Lambda$ decay and show how the measurement of these quantities, particularly $N_p$, can lead to a determination of $\Gamma_n / \Gamma_p$, the ratio of neutron to proton induced $\Lambda$ decay. We also show that the consideration of the two-nucleon induced channel has a repercussion in the results, widening the band of allowed values of $\Gamma_n / \Gamma_p$ with respect to what is obtained neglecting this channel.Comment: 30 pages, 12 Postscript figures, uuencoded file, ReVTeX, epsf.st

Gouvernance de la politique drogue dans les villes suisses

La loi fédérale suisse sur les stupéfiants (LStup) confère aux cantons la responsabilité de mettre en oeuvre les mesures relatives au modèle des quatre piliers de lutte contre les addictions : la prévention, la thérapie et l'insertion, la réduction des risques et l'aide à la survie, ainsi que la répression. Les villes sont concernées au premier titre par les mesures en matière de drogue déployées sur leur territoire, en particulier de celles relatives à la réduction des risques. Les acteurs concernés par les différents piliers ainsi que les deux niveaux institutionnels des villes et des cantons posent ainsi la question du pilotage des prestations. Le concept de gouvernance offre un cadre d'analyse permettant de comprendre comment les différentes autorités publiques ont organisé leur dispositif. La perspective historique montre ainsi que les autorités ont été amenées à intervenir pour faire face à des situations dramatiques comme les scènes ouvertes en Suisse-allemande. Les dispositifs sont aujourd'hui relativement similaires, mis à part pour les questions de réduction des risques. On peut observer d'ailleurs un éclatement de ce concept entre différentes offres d'aide à la survie pour les populations précaires de façon générale, ainsi que de la recherche de compatibilité urbaine. Il s'agit ainsi de s'assurer que les personnes en difficulté bénéficient d'une aide adéquate tout en maintenant les nuisances potentielles liées aux mesures à un niveau infime pour la population. Différents modes de pilotage ont été déterminés en dégageant des instances de pilotage stratégique et opérationnel et ont montré le rôle important des délégués des villes en matière de drogue. Une fonction d'autant plus importante que le problème est aigu