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Two algorithms for coloring large order graphs by partitioning, as related to class scheduling with a computer, are developed. Although, the two main algorithms failed to produce acceptable results for application to class scheduling, a coloring algorithm developed for use in the two main algorithms, is an improvement over known existing coloring algorithms. http://archive.org/details/agraphoreticppro1094515737 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

On-line re-scheduling of trains aims to find accurate solutions after an incident has occurred on the railway network. When we consider a large area, solutions consist in calculating new timetables, sequences and routes of trains. This problem asks for decision support tools based on operational research techniques. This thesis aims to develop solutions toward an operational tool, it articulates around three main parts. The first part defines an exhaustive model of the railway system operations and a multiscalable description of the infrastructure. The second part presents three mathematical models of the rescheduling problem associated with this description. We preset a exhaustive continuous time based model including headways that take into account speeds of trains, plus a discrete time based model and an hybrid model combining both formulations. The last part describes first implementations and the global framework we need to develop in order to solve the real world problem. It emphases on expected synergies, specilaly between simulation and optimization techniques., La régulation ferroviaire sur de vastes zones est un problème complexe. Elle intervient dans la phase opérationnelle de la production. Son rôle consiste à trouver de nouvelles solutions en termes de planification des mouvements de trains suite à l'apparition d'un incident empêchant la réalisation normale du plan de transport préétabli dans les phases amont de la production. La contribution de ce travail s'organise autour de trois axes. Le premier consiste à définir une formalisation exhaustive du système ferroviaire, associé à une représentation plus cohérente (modèle multiniveau). Le deuxième axe s'articule autour de l'étude des modèles mathématiques pour la régulation du trafic ferroviaire: évolutions d'un modèle en temps continu complet (espacements dynamiques), proposition d'un modèle innovant à temps discret et d'un modèle mixte (continu-discret) adossé au modèle multiniveau. Enfin, le dernier axe traite de la mise en oeuvre concrète au niveau industriel, en particulier des gains attendus du couplage avec un outil de simulation.

In passenger railway operations, unforeseen events require railway operators to adjust their timetable and their resource schedules. The passengers will also adapt their routes to their destinations. When determining the new timetable and rolling stock schedule, the railway operator has to take passenger behavior into account. The operator should increase the capacity of trains for which the operator expects more demand than on a regular day. Furthermore, the operator could increase the frequency of the trains that serve stations with an additional demand.This paper describes a real-time disruption management approach which integrates the rescheduling of the rolling stock and the timetable by taking the changed passenger demand into account. The timetable decisions are limited to additional stops of trains at stations at which they normally would not call. Several variants of the approach are suggested, with the difference in how to determine which additional stops should be executed.Real-time rescheduling requires fast solutions. Therefore a heuristic approach is used. We demonstrate the performance of the several variants of our algorithm on realistic instances of Netherlands Railways, the major railway operator in the Netherlands.

Sea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29°C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches.

Or, rather, in the timetable . [ABSTRACT FROM PUBLISHER]

From the Washington Post editorial discussing the approach to Iraq policy of the presumptive Democratic nominee.: [ABSTRACT FROM PUBLISHER]