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Myriame T.I.B Bollen Col Eric T. Linssen Ir. Sebastiaan J.H. Rietjens 《Small Wars & Insurgencies》2013,24(4):437-448
This chapter discusses the impact Provincial Reconstruction Teams (PRTs) have on the security situation in Afghanistan, specifically in countering the terrorist threat and in counter-narcotics. The Afghan people define the lack of security as their country's greatest problem. The terrorist activities of groups opposed to the central government and the political process compounded by violence related to the opium trade are seen as the main sources of insecurity. The authors argue that, currently, PRTs should not assume active counterterrorism as an additional main area of operation. The complexity of Afghanistan's security environment and the pressure to have PRTs involved in the counter-narcotics effort underscore the necessity of local knowledge and experience in the PRTs. Participation of indigenous actors, such as NGOs, in the PRT-organisational structure could provide this required expertise. 相似文献
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Since the 1st oil crisis in 1973, the economies of sub-Saharan Africa have barely kept pace with their burgeoning populations. Women in Sub-Saharan Africa give birth more often than women in any other region of the world, with an average of more than 6.5 live births each. The region's natural increase average 2.5% a year in the 1960s, 2.7% in the 1970s, and in the mid-1980s, it is 3.1% per annum--a rate that will double the regions population in 22 years. National leaders in Sub-Saharan Africa were slow to consider population policy as a key component of the social and economic development effort. The neglect of population issues is reflected in the limited scope of public or private family planning programs in the sub-continent. Donor countries and institutions play an important role in developing the information base by providing technical training to government staff, supporting research, and disseminating information to a broad spectrum of political actors. Some examples of policy reconsiderations in Nigeria, Zambia, Liberia, and Niger are given. These countries are starting to give active consideration to population policies to reduce fertility and high rates of population growth by expanding family planning services, raising the age of marriage, improving the status of women, providing family-life education, and incorporating economic incentives for smaller families into the provision of social services. The highly centralized nature of African governments dictates that the acquiescence of the governmental elite must be obtained before any policy can take hold. Overall, high population growth rates in combination with a stagnating social and economic development effort throughout the region have provided the catalyst for a new look at Sub-Saharan Africa population policy. The ability of African nations to implement policies that reduce fertility is more open to question; no African nation has as yet done so, and the socioeconomics factors contributing to high fertility remain strong. 相似文献
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David I. Steinberg 《海军后勤学研究》1970,17(2):217-235
The fixed charge problem is a nonlinear programming problem of practical interest in business and industry. Yet, until now no computationally feasible exact method of solution for large problems had been developed. In this paper an exact algorithm is presented which is computationally feasible for large problems. The algorithm is based upon a branch and bound approach, with the additional feature that the amount of computer storage required remains constant throughout (for a problem of any given size). Also presented are three suboptimal heuristic algorithms which are of interest because, although they do not guarantee that the true optimal solution will be found, they usually yield very good solutions and are extremely rapid techniques. Computational results are described for several of the heuristic methods and for the branch and bound algorithm. 相似文献
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Charles I. Tiplitz 《海军后勤学研究》1973,20(2):367-375
Calculating the solution for a mixed integer linear programming problem has been problematic for any sizable dimension because of the time required. Accordingly, an improved method for the fixed charge problem is presented here. The method is a modification of a bounding technique first suggested by Balinski, and it exploits fully the ratio of costio-use, first described by Cooper and Drebes. It exploits those local properties which have global application so that enumeration is confined to those relatively few combinations which cannot be evaluated otherwise. 相似文献
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The problem posed in this paper is to sequence or route n jobs, each originating at a particular location or machine, undergoing r?1 operations or repairs, and terminating at the location or machine from which it originated. The problem is formulated as a 0-1 integer program, with block diagonal structure, comprised of r assignment subproblems; and a joint set of constraints to insure cyclical squences. To obtain integer results the solutions to each subproblem are ranked as required and combinations thereof are implicitly enumerated. The procedure may be terminated at any step to obtain an approximate solution. Some limited computational results are presented. 相似文献
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Moment and maximum likelihood estimates (m.l.e.'s) arc investigated for nonparametric and parametric models for a single server queue observed over a random time horizon, namely, up to the nth departure epoch. Also. m.l.e's of the mean interarrival time and mean service time in anM/M/1 queue observed over a fixed time-interval are studied Limit distributions of these estimates are obtained Without imposing steady state assumptions on the queue-size or waiting time processes. 相似文献
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Stig I. Rosenlund 《海军后勤学研究》1978,25(1):107-119
The busy period, busy cycle, and the numbers of customers served and lost therein, of the G/M/m queue with balking is studied via the embedded Markov chain approach. It is shown that the expectations of the two discrete variables give the loss probability. For the special case G/M/1/N a closed expression in terms of contour integrals is obtained for the Laplace transform of these four variables. This yields as a byproduct the LIFO waiting time distribution for the G/M/m/N queue. The waiting time under random order service for this queue is also studied. 相似文献