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排序方式: 共有88条查询结果,搜索用时 31 毫秒
21.
Ant Colony Optimisation for Machine Layout Problems 总被引:1,自引:0,他引:1
Flexible machine layout problems describe the dynamic arrangement of machines to optimise the trade-off between material handling and rearrangement costs under changing and uncertain production environments. A previous study used integer-programming techniques to solve heuristically reduced versions of the problem. As an alternative, this paper introduces an ant colony optimisation (ACO) algorithm to generate good solutions. Experimental results are presented, with ACO obtaining better solutions than the reduction heuristic. 相似文献
22.
Maurice Koster 《Mathematical Methods of Operations Research》2006,64(3):429-444
The directional serial rule is introduced as a natural serial extension, generalizing the Moulin–Shenker cost sharing rule to heterogeneous cost sharing models. It is the unique regular rule compatible with the radial serial principle. In particular, this shows the incompatibility of the serial principle with differentiability of a cost sharing rule as a function of the individual demands.I would like to thank the editor and the referee for their comments which have been most useful. 相似文献
23.
The present paper examines the sequential location—allocation problems of public facilities in one- and two-dimensional space under several policies. It is shown that the efficiency loss due to the adoption of a myopic policy is not so large, contrary to common belief, provided that the efficiency can be measured by the total transportation cost of users and by the total capacity of facilities. If the total serving area is sufficiently narrow, then the spatial allocations of optimal solutions in two-dimensional problems can be closely approximated by those in one-dimensional problems. 相似文献
24.
The isotopic analysis of boron from material that carries only trace amounts of boron requires low boron blank levels. Large efforts are taken to keep blank levels low by purifying reagents. We performed exposure experiments and determined procedure blanks before and after the air-handling system was modified from silicate glass filters to polyethylene/polystyrole and active carbon filters. Our investigations demonstrate that the air-handling system may be the major source of boron blank in many laboratories, as the widely used silicate glass filters, which contain boron as a major component, in the form of borax and boric acid, release significant amounts of boron to the air. 相似文献
25.
Klaus Peter Jungmann 《Hyperfine Interactions》2006,171(1-3):41-55
State of the art laser technology and modern spectroscopic methods allow to address issues of fundamental symmetries and fundamental
interactions in atoms with high precision experiments. In particular the discrete symmetries Parity (P), Charge Conjugation
(C), Time Reversal (T) as well as their combinations CP and CPT are in the center of interest at present. Actual projects
are concerned with Parity Violation in atoms, Time Reversal Violation in β-decays and searches for permanent Electric Dipole Moments (EDMs), and tests of CPT conservation in particle-antiparticle
properties, in particular antiprotonic atoms.
This work is supported in part by the Dutch Stichting voor Fundamenteel Onderzoek der Materie (FOM) under programme number
48 (TRIμP). 相似文献
26.
27.
程郁琨 《数学的实践与认识》2010,40(19)
顾客为子树结构的树上反中心选址问题是在树T上寻找一点(位于顶点处或在边的内部),使得该点与子树结构的顾客之间的最小赋权带加数距离尽可能地大.给出了该问题的一个有效算法,其时间复杂度为O(cn+sum from j=1 to m n_j),其中n_j为各子树T_j的顶点个数,c为不同的子树权重个数,n为树的顶点数. 相似文献
28.
In recent years, there has been an increasing worldwide interest in accelerator driven systems (ADS) due to their perceived
superior safety characteristics and their potential for burning actinides and long-lived fission products. Indian interest
in ADS has an additional dimension, which is related to our planned large-scale thorium utilization for future nuclear energy
generation.
The physics of ADS is quite different from that of critical reactors. As such, physics studies on ADS reactors are necessary
for gaining an understanding of these systems. Development of theoretical tools and experimental facilities for studying the
physics of ADS reactors constitute important aspect of the ADS development program at BARC. This includes computer codes for
burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical
facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods.
The paper discusses the physics issues specific to ADS reactors and presents the status of the reactor physics program and
some of the ADS concepts under study.
相似文献
29.
A. F. Panusenkow 《Isotopes in environmental and health studies》2013,49(12):369-373
Im Jahre 1979 begeht der Rat für Gegenseitige Wirtschaftshilfe (RGW) — die erste internationale wirtschaftliche und wissenschaftlich-technische Organisation der sozialistischen Länder in der Welt — den 30. Jahrestag seines Bestehens. Im Januar 1949 fand in Moskau eine Beratung von Vertretern Bulgariens, Ungarns, Polens, Rumaniens, der Sowjetunion und der Tschechoslowakei statt. Die Teilnehmer der Beratung sahen es als notwendig an, zur Organisierung einer breiteren okonomischen Zusammenarbeit einen Rat für GegenseitigeWirtschaftshilfe zu schaffen. Im April des gleichen Jahres trat der RGW zu seiner ersten Tagung zusammen. Damit nahm die praktische Tätigkeit dieser Organisation ihren Anfang. 相似文献
30.
A. Divsalar P. Vansteenwegen K. Sörensen D. Cattrysse 《European Journal of Operational Research》2014
In this paper, a memetic algorithm is developed to solve the orienteering problem with hotel selection (OPHS). The algorithm consists of two levels: a genetic component mainly focuses on finding a good sequence of intermediate hotels, whereas six local search moves embedded in a variable neighborhood structure deal with the selection and sequencing of vertices between the hotels. A set of 176 new and larger benchmark instances of OPHS are created based on optimal solutions of regular orienteering problems. Our algorithm is applied on these new instances as well as on 224 benchmark instances from the literature. The results are compared with the known optimal solutions and with the only other existing algorithm for this problem. The results clearly show that our memetic algorithm outperforms the existing algorithm in terms of solution quality and computational time. A sensitivity analysis shows the significant impact of the number of possible sequences of hotels on the difficulty of an OPHS instance. 相似文献