This paper presents an Ant Colony System algorithm hybridized with insertion heuristics for the Time-Dependent Vehicle Routing Problem with Time Windows (TDVRPTW). In the TDVRPTW a fleet of vehicles ...must deliver goods to a set of customers, time window constraints of the customers must be respected and the fact that the travel time between two points depends on the time of departure has to be taken into account. The latter assumption is particularly important in an urban context where the traffic plays a significant role.
A shortcoming of Ant Colony algorithms for capacitated routing problems is that, at the final stages of the algorithm, ants tend to create infeasible solutions with unrouted clients. Hence, we propose enhancing the algorithm with an aggressive insertion heuristic relying on the minimum delay metric. Computational results confirm the benefits of more involved insertion heuristics. Moreover, the resulting algorithm turns out to be competitive, matching or improving the best known results in several benchmark problems.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The sensitivity of a gravitational wave detector based on a laser interferometer is limited by photon shot noise for signals with frequencies above a few hundred hertz. The amplitude of this noise ...depends on the interferometer fringe contrast. By means of a complete simulation, we show that using a short optical cavity placed at the interferometer output port, the contrast can be significantly improved and the optimal sensitivity recovered. Such an output mode-cleaner has been realized and tested. The adopted design and the results of the tests are presented.
The VIRGO Central Interferometer (CITF) is a short suspended interferometer operated with the central area elements of the VIRGO detector. The main motivation behind the CITF is to allow the ...integration and debugging of a large part of the subsystems of VIRGO while the construction of the long arms of the antenna is being completed. This will permit a faster commissioning of the full-size antenna. In fact, almost all the main components of the CITF, with the exception of the large mirrors and a few other details, are the same as those to be used for the full-size detector. In this paper the present status of the VIRGO CITF is reported.
Teratology and tumors: origins MONTANA RAMONET, J M
Odontoiatria; revista ibero-americana de medicina de la boca,
1953, Volume:
10, Issue:
112
Journal Article
Dental caries and its relation to pregnancy MONTANA RAMONET, J M; BARAJA CARCELLER, M
Odontoiatria; revista ibero-americana de medicina de la boca,
1953, Volume:
10, Issue:
113
Journal Article
