Solving a static repositioning problem in bike-sharing systems using iterated tabu search

In this paper, we study the static bike repositioning problem where the problem consists of selecting a subset of stations to visit, sequencing them, and determining the pick-up/drop-off quantities (associated with each of the visited stations) under the various operational constraints. The objective is to minimize the total penalties incurred at all the stations. We present an iterated tabu search heuristic to solve the described problem. Experimental results show that this simple heuristic can generate high quality solutions using small computing times.postprin

Ruthenium nanoparticles supported on hydroxyapatite as an efficient and recyclable catalyst for cis-dihydroxylation and oxidative cleavage of alkenes

Impregnation of hydroxyapatite with colloidal ruthenium results in the formation of a catalyst that effects cis-dihydroxylation and oxidative cleavage of alkenes to their respective cis-1,2-diols and carbonyl products in good to excellent yields (see scheme). The supported ruthenium catalyst can be easily recycled and reused for consecutive reaction runs without significant deterioration of the catalytic activities. R1, R2 = H, alkyl, aryl.postprin

An artificial bee colony algorithm for the capacitated vehicle routing problem

Session MF-03: Population-based metaheuristics for routing problems - Stream: Metaheuristics - Invited session no. 3This paper introduces an artificial bee colony heuristic for the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. The performance of the heuristic is evaluated on two sets of benchmark instances. A new scheme is also developed to improve the performance of the artificial bee colony heuristic. Computational results show that the heuristic with the new scheme produces good solutions.postprintThe 24th European Conference on Operational Research (EURO 24), Lisbon, Portual, 11-14 July 2010. In Abstract Book of EURO 24, 2010, p. 89, MF-03-

An artificial bee colony algorithm for the capacitated vehicle routing problem

This paper introduces an artificial bee colony heuristic for solving the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. An enhanced version of the artificial bee colony heuristic is also proposed to improve the solution quality of the original version. The performance of the enhanced heuristic is evaluated on two sets of standard benchmark instances, and compared with the original artificial bee colony heuristic. The computational results show that the enhanced heuristic outperforms the original one, and can produce good solutions when compared with the existing heuristics. These results seem to indicate that the enhanced heuristic is an alternative to solve the capacitated vehicle routing problem. © 2011 Elsevier B.V. All rights reserved.postprin

Ictal cerebral Single Photon Emission Computerized Tomography (SPECT) scan is a sensitive and safe investigation for seizure localization

published_or_final_versio

Regional cerebral blood flow study in postictal psychosis complication complex partial seizure

published_or_final_versio

The reliability-based stochastic transit assignment problem with elastic demand

This paper examines the reliability-based stochastic transit assignment problem with elastic demand. A Variational Inequality (VI) model for this problem is developed. The VI model considers capacity, waiting time and in-vehicle travel time as stochastic variables, and includes Spiess and Florian’s (1989) and de Cea and Fernández’s (1993) models as special cases. A reliability-based stochastic user equilibrium condition is defined to capture the route choice behavior of passengers. To illustrate the properties of the VI model, numerical studies were conducted on de Cea and Fernández’s (1993) network. The studies also show that Spiess and Florian’s and de Cea and Fernández’s models can overestimate the system performance substantially.postprin

Enucleation of painful blind eye for refractory intraocular lymphoma after dose-limiting chemotherapy and radiotherapy

published_or_final_versionSpringer Open Choice, 25 May 201

Improving efficiency roll-off in organic light emitting devices with a fluorescence-interlayer-phosphorescence emission architecture

Organic light emitting devices (OLEDs) with a fluorescence-interlayer- phosphorescence emission layer structure (FIP EML) has been proposed to solve the efficiency roll-off issue effectively. Efficient green OLED based on FIP EML exhibiting only 26% roll-off in the luminance efficiency, which is lower than the typical roll-off of 51% for conventional phosphorescent OLEDs with single EML operated at 5-150 mA/cm2 range, has been demonstrated. Such enhancement should be attributed to the improved carrier balance, the exciton redistribution in recombination zone, the suppression of nonradiative exciton quenching processes, and the elimination of energy transfer loss offered by the FIP EML structure. © 2009 American Institute of Physics.published_or_final_versio

Osteoporotic insufficiency fractures of the pelvis

Insufficiency fractures are a subtype of stress fractures which occur when normal or physiological stresses are placed on weakened bone. The main predisposing cause is osteoporosis. The clinical and radiological features of two elderly women with pelvic insufficiency fractures are described. Isotope bone scan is the most sensitive imaging modality for the detection of these fractures. Computed tomography is useful for confirming these fractures and excluding malignancy. As pelvic insufficiency fractures are difficult to detect clinically, application of the appropriate radiological investigation is necessary for diagnosis. With early recognition of this entity, the patient could be managed appropriately, thus avoiding any unnecessary invasive investigations.published_or_final_versio