一种改进的指纹图像局部方向场匹配方法

指纹方向场真实地反映了指纹图像中本质的纹理特征,包括了指纹的基本形状、结构和走势。定义了局部方向场图像的描述方法,可以根据纹理信息有效地描述并区分不同的细节点。在低质量指纹图像,特别是存在较严重非线性形变的指纹图像中,细节点方向属性不够可靠,使得以细节点对作为参考对齐局部方向场图像的方法效果不佳。提出一种改进的局部方向场图像对齐和匹配方法,能够明显改善局部对齐效果,提高局部匹配的准确性,从而更加有效地区分对应和不对应细节点。实验结果验证了提出方法的有效性。     

Local search methods for the discrete time/resource trade-off problem in project networks

In this paper we consider the discrete time/resource trade-off problem in project networks. Given a project network consisting of nodes (activities) and arcs (technological precedence relations), in which the duration of the activities is a discrete, nonincreasing function of the amount of a single renewable resource committed to it, the discrete time/resource trade-off problem minimizes the project makespan subject to precedence constraints and a single renewable resource constraint. For each activity, a work content is specified such that all execution modes (duration/resource requirement pairs) for performing the activity are allowed as long as the product of the duration and the resource requirement is at least as large as the specified work content. We present a tabu search procedure which is based on a decomposition of the problem into a mode assignment phase and a resource-constrained project scheduling phase with fixed mode assignments. Extensive computational experience, including a comparison with other local search methods, is reported. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 553–578, 1998     

一种新的保持分形特征的分形变形方法

针对IFS吸引子变形过程中间出现的分形特征退化的问题,提出基于局部吸引子的近似凸包及旋转匹配的特征对应方法.IFS吸引子的局部吸引子可由独立的IFS生成,IFS中每个压缩仿射映射存在不动点,构造所有不动点的凸包,即得到局部近似凸包;证明了局部近似凸包间的相似对应等价于局部吸引子间的相似对应,并提出了通过旋转匹配的特征对应方法实现局部近似凸包的配对,最后计算所有配对下相似度最高的一组局部近似凸包匹配,确定局部吸引子间的特征对应,即IFS特征对应.对两个IFS进行线性插值可实现保持分形特征的分形变形.     

维和任务区当地译员的重要作用与素质要求

维和行动中的当地译员是一个特殊群体,在维和任务中具有重要作用。当地译员必须具备保密性、中立性、服务性等基本素质。因此,最大限度地调动当地译员的工作热情、提高其职业素质、是保证维和行动顺利完成的重要环节。     

ECONOMIC GROWTH AND VIOLENT INTERNATIONAL CONFLICT: 1875–1999

This paper extends the joint product model of military alliances to apply to the new strategic doctrine adopted by NATO in the 1990s. In particular, a choice must be made between protecting one's own territory and pooling forces for an alliancewide rapid reaction force. This new model accounts for a host of externalities and their implications for burden sharing, full financing, and allocative efficiency. The Pigouvian taxes that adjust for force thinning and attack deflection are shown to finance optimal border‐protecting forces under a variety of circumstances. Second‐best considerations arise owing to the pure publicness of rapid reaction forces. The ideal toll arrangement does not currently characterize NATO financing, nor is it likely to do so.     

Rebels of the frontier: origins,organization, and recruitment of the Pakistani Taliban

The Pakistani Taliban, factionalized into some 40 groups, form a decentralized insurgent movement, often characterized by infighting, divergent motivations, and a shifting web of alliances. The Pakistani Taliban remain little understood because most scholars have avoided a serious treatment of the insurgent movement and instead focused on analyzing the geopolitics of the region and Pakistan's ‘double game’. This article seeks to fill this gap by dissecting the movement through selected theories of organization and mobilization. First, I explain the various dimensions of the conflict and the origins of the insurgency. Next, I discuss the Pakistani Taliban's political organization, categorizing it as composed of various warlord regimes. I further list the Taliban's component groups and numerical strength and chart the leadership structure. Lastly, I analyze insurgent recruitment strategies, accounting for the role of selective incentives, coercion, and genuine grievances.     

高科技武器装备发展推动作战理念的创新

结合美国在近几年的几次局部战争中所使用的高科技的信息化武器装备、远程作战武器和精确打击武器等武器装备,研究分析了高科技武器装备的发展动态,促进产生了一些新的作战理念(战术战法、作战理论),如网络中心战、夺取制信息权、非对称作战和非线性作战,而新的作战理念又推动了高科技武器装备的完善和进一步发展。同时还分析了高科技武器装备目前尚存在的一些不足。     

具有拟周期外力的非自治发展方程的时滞惯性流形与近似惯性流形

研究了一类具有拟周期外力的非自治发展方程,通过延伸相平面将非自治系统转化为自治系统,再证明相应的自治系统的时滞惯性流形的存在性,并在时滞惯性流形的基础上构造了非自治发展方程的近似惯性流形。     

The interaction between local and international power in EU police reform in Bosnia and Herzegovina

ABSTRACT

This article explores the interaction between local and international power structures in EU peacebuilding. While citizens in a state only face order from one authority (the state), local actors in a peacebuilding context are subject to orders from two institutions (the domestic state and the peacebuilding mission). This article explores the nature of interactions of these two institutions and their effect on local police officers’ compliance and resistance. Specifically, it analyzes the example of the police restructuring process in Bosnia and Herzegovina. It demonstrates that the choices of local officers to comply or resist depended on whether the interactions between the EU Police Mission and the local police organization were positive and mutually supportive, or whether they were competitive and contradictory. The findings of the article contribute to the debates on the role of local power and the importance of local legitimacy in peacebuilding.     

结合全局与局部信息的主动轮廓分割模型

针对传统的基于区域的主动轮廓模型在分割灰度不均匀图像和噪声图像存在效果不佳的问题,提出结合全局项与局部项的主动轮廓分割模型。全局项由CV(Chan-Vese)模型的保真项构成,局部项的构建考虑局部区域信息的同时引入反映图像灰度特性的局部熵信息。依据图像灰度的特点,选择合理的全局项和局部项参数,并加入正则项保证曲线在演化过程中保持平滑,保障分割结果的可靠性。通过变分水平集方法最小化能量泛函,依据梯度下降流迭代更新水平集,完成曲线演化。采用模拟图像和实际图像进行实验分析,结果表明,所提出的结合全局项和局部项的主动轮廓模型可以高效地分割噪声严重以及灰度分布不均匀的图像。