排序方式: 共有35条查询结果,搜索用时 281 毫秒
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W. Dick A. Karl R. D. Evans Frau P. Curie F. Behounek W. Bothe N. E. Dorsey P. Ludewig W. A. Sokolow A. Piccard L. Meylan A. J. Allen J. A. C. Teegan A. S. Eve J. Katzmann C. L. Utterbeck D. Devaputra R. G. Franklin E. Witte H. A. Doerner und W. M. Hoskins 《Fresenius' Journal of Analytical Chemistry》1934,98(5-6):194-207
Ohne Zusammenfassung 相似文献
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A variable neighborhood search for the capacitated arc routing problem with intermediate facilities 总被引:2,自引:0,他引:2
Michael Polacek Karl F. Doerner Richard F. Hartl Vittorio Maniezzo 《Journal of Heuristics》2008,14(5):405-423
The capacitated arc routing problem (CARP) focuses on servicing edges of an undirected network graph. A wide spectrum of applications
like mail delivery, waste collection or street maintenance outlines the relevance of this problem. A realistic variant of
the CARP arises from the need of intermediate facilities (IFs) to load up or unload the service vehicle and from tour length
restrictions. The proposed Variable Neighborhood Search (VNS) is a simple and robust solution technique which tackles the
basic problem as well as its extensions. The VNS shows excellent results on four different benchmark sets. Particularly, for
all 120 instances the best known solution could be found and in 71 cases a new best solution was achieved. 相似文献
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H. A. Doerner 《Fresenius' Journal of Analytical Chemistry》1930,79(5-6):207-208
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Michael Polacek Karl F. Doerner Richard F. Hartl Guenter Kiechle Marc Reimann 《European Journal of Operational Research》2007
The problem considered in this paper deals with determining daily routes for a traveling salesperson who provides customers in Upper Austria with product range information of a large, global food wholesaler. Each customer has to be visited at least once a year, with some customers requiring up to one visit per month. Further, some customers may not be visited each day of the week. Our decision support system uses a commercial GIS software to extract customer data for input into the optimization procedure and to visualize the results obtained by the algorithm. The optimization approach is based on the variable neighborhood search algorithm which assigns customers to days and determines routes for the salesperson for each day with the primary objective to minimize the total travel time of the salesperson. Another objective studied is to minimize the number of days needed by the salesperson to visit all customers in a given month. Further we analyze the effects of changes in the business environment like increases in the amount or flexibility of the salesperson’s working time and variations in the possible days for customer visits. Finally, we enrich the objective function by considering periodicity requirements for customer visits. Specifically, we penalize irregular schedules, where the time between two successive customer visits varies. 相似文献
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A multiobjective combinatorial optimization (MOCO) formulation for the following location-routing problem in healthcare management is given: For a mobile healthcare facility, a closed tour with stops selected from a given set of population nodes has to be found. Tours are evaluated according to three criteria: (i) An economic efficiency criterion related to the tour length, (ii) the criterion of average distances to the nearest tour stops corresponding to p-median location problem formulations, and (iii) a coverage criterion measuring the percentage of the population unable to reach a tour stop within a predefined maximum distance. Three algorithms to compute approximations to the set of Pareto-efficient solutions of the described MOCO problem are developed. The first uses the P-ACO technique, and the second and the third use the VEGA and the MOGA variant of multiobjective genetic algorithms, respectively. Computational experiments for the Thiès region in Senegal were carried out to evaluate the three approaches on real-world problem instances. 相似文献
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A Variable Neighborhood Search for the Multi Depot Vehicle Routing Problem with Time Windows 总被引:6,自引:0,他引:6
Michael Polacek Richard F. Hartl Karl Doerner Marc Reimann 《Journal of Heuristics》2004,10(6):613-627
The aim of this paper is to propose an algorithm based on the philosophy of the Variable Neighborhood Search (VNS) to solve Multi Depot Vehicle Routing Problems with Time Windows. The paper has two main contributions. First, from a technical point of view, it presents the first application of a VNS for this problem and several design issues of VNS algorithms are discussed. Second, from a problem oriented point of view the computational results show that the approach is competitive with an existing Tabu Search algorithm with respect to both solution quality and computation times. 相似文献
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Luana Bettanin Sumbal Saba Carlos V. Doerner Marcelo S. Franco Marcelo Godoi Jamal Rafique Antonio L. Braga 《Tetrahedron》2018,74(29):3971-3980
Herein, we described the NH4I-catalyzed CH bond chalcogenation of N-heteroaryls in the presence of a minimum amount of DMSO/H2O/acetic acid as additives (2.5/2.5/1?M equiv., respectively), under metal-free conditions. Under optimized conditions, a wide variety of sulfenyl/selenyl imidazo[1,2-α]pyridines were prepared in very good yields. Moreover, the present approach was also highly efficient for the chalcogenation of different 5-membered N-heteroaryls, e.g., indole, imidazothiazole, indazole and imidazopyrimidine derivatives. 相似文献
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