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提出了一种基于傅里叶-梅林变换和二叉树支持向量机相结合的舰船目标一维距离像识别方法。该方法充分利用了傅里叶-梅林变换具有的时移与尺度不变性和支持向量机在小样本分类中的优势,可以改善目标的特征稳定性,提高识别性能。针对多类舰船目标的识别,提出采用聚类分析中的均值距离来生成二叉树,将分类器分布在各个节点上,构成了多类支持向量机,减少了分类器数量和重复训练样本的数量。对4类舰船目标仿真实验的结果表明,该分类方法具有较高的识别性能、较快的识别速度。 相似文献
414.
加肋轴对称薄壳的强度问题,需要考虑肋骨的作用。针对该问题,采用轴对称曲边壳单元建立了肋骨单元的刚度矩阵,将该矩阵叠加到轴对称曲边壳单元的刚度矩阵中,对加肋轴对称薄壳的强度进行有限元分析。应用Fortran语言编写了有限元计算程序,对一个精车模型进行了强度计算,计算结果同模型试验结果吻合良好,表明该方法可以应用于加肋轴对称薄壳的强度分析。 相似文献
415.
Michael A. Innes 《Small Wars & Insurgencies》2013,24(2):241-251
Numerous writers have acknowledged the importance of radio communications and hate propaganda in the Liberian civil war (1990–1997), but none have explored the subject in depth. A wide variety of related issues have been neglected, including military efforts to seize control of broadcast facilities, the deliberate manipulation of public information and perceptions, and the implications of both for wartime atrocities and post-war justice. In the following essay, I identify and discuss six general strands of thought on guerrilla radio broadcasting and communications in wartime Liberia. The first looks to the relationship between mass media and the state in the pre-civil war era. The second covers the cooption of the wartime free press. Three further themes – Charles Taylor's cultivation of personal power, the relevance of broadcasting for rebel command and control capabilities, and Taylor's media dominance during the 1997 Presidential campaign – demonstrate the strategic and public roles of radio communications and broadcasting. Finally, I look to written survivor memoirs for elite responses to wartime media monopolies, guerrilla propaganda, and psychological warfare. I conclude with some notes on indicators for future research, and their implications for historical and contemporary issues in Liberia. 相似文献
416.
A dynamic version of the transportation (Hitchcock) problem occurs when there are demands at each of n sinks for T periods which can be fulfilled by shipments from m sources. A requirement in period t2 can be satisfied by a shipment in the same period (a linear shipping cost is incurred) or by a shipment in period t1 < t2 (in addition to the linear shipping cost a linear inventory cost is incurred for every period in which the commodity is stored). A well known method for solving this problem is to transform it into an equivalent single period transportation problem with mT sources and nT sinks. Our approach treats the model as a transshipment problem consisting of T, m source — n sink transportation problems linked together by inventory variables. Storage requirements are proportional to T2 for the single period equivalent transportation algorithm, proportional to T, for our algorithm without decomposition, and independent of T for our algorithm with decomposition. This storage saving feature enables much larger problems to be solved than were previously possible. Futhermore, we can easily incorporate upper bounds on inventories. This is not possible in the single period transportation equivalent. 相似文献
417.
We consider the scheduling of n jobs on m identical machines when the jobs become available for processing at ready times ai, ai, ? 0, require di time units for processing and must be completed by times bi for i = 1, 2, … n. The objective chosen is that of minimizing the total elapsed time to complete all jobs subject to the ready time and due date constraints, preemption is not allowed. We present a multi-stage solution algorithm for this problem that is based on an implicit enumeration procedure and also uses the labelling type algorithm which solves the problem when preemption is allowed. 相似文献
418.
Michael Evans 《Small Wars & Insurgencies》2013,24(2):175-195
This article examines the vital importance of political ideology in formulating effective counterinsurgency, by examining the case of Rhodesia between 1965 and 1980. During this period, the Rhodesian Front (RF) Government of Ian Smith adopted a radical right-wing ‘world-struggle ideology’ to justify settler resistance to African decolonisation. The RF's ideology, based on settler-status anxiety, upheld a conspiratorial interpretation of modern politics that emphasised virulent forms of Anglophobia, anti-communism, anti-internationalism and anti-liberalism. The Smith Government portrayed African nationalism not as an indigenous political phenomenon, but as an external instrument of world communism and Western appeasement. After 1972, when Rhodesia faced a protracted insurgency, many of the principles of RF ideology were applied to counterinsurgency warfare with disastrous results. Because the Rhodesian Government viewed African guerrilla warfare as unrelated to domestic politics, Rhodesian counterinsurgency lacked a realistic political dimension. The dictates of settler ideology blinded the Rhodesian Government to the vital need to win ‘hearts and minds’ by applying timely principles of political pacification and reform to its counterinsurgency effort. Instead a Rhodesian counterinsurgency campaign of maximum force was pursued. Such a campaign proved counter-productive accelerating strategic deterioration and leading ultimately to the political victory of the African guerrilla cause in 1980. 相似文献
419.
In the classical EPQ model with continuous and constant demand, holding and setup costs are minimized when the production rate is no larger than the demand rate. However, the situation may change when demand is lumpy. We consider a firm that produces multiple products, each having a unique lumpy demand pattern. The decision involves determining both the lot size for each product and the allocation of resources for production rate improvements among the products. We find that each product's optimal production policy will take on only one of two forms: either continuous production or lot‐for‐lot production. The problem is then formulated as a nonlinear nonsmooth knapsack problem among products determined to be candidates for resource allocation. A heuristic procedure is developed to determine allocation amounts. The procedure decomposes the problem into a mixed integer program and a nonlinear convex resource allocation problem. Numerical tests suggest that the heuristic performs very well on average compared to the optimal solution. Both the model and the heuristic procedure can be extended to allow the company to simultaneously alter both the production rates and the incoming demand lot sizes through quantity discounts. Extensions can also be made to address the case where a single investment increases the production rate of multiple products. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004. 相似文献
420.