Brazil's new defense paradigm

In 2015, Brazil has taken steps toward re-consolidating its domestic defense industry. In the 1980s, Brazil built a dynamic and diversified defense industry. The state-driven effort resulted in a tripod strategy, where the state, state-run companies, and their private sector became the pillars of Brazil's defense industry. Brazil developed an export-driven defense industry; where close to 80–90% of its output was exported to Latin American, African, Arab, and Asian nations. In the 1980s, Brazil became the world's fifth largest exporter of defense products and services, exporting to over 40 countries. In the 1990s and 2000s, Brazil's defense industry suffered a dramatic reduction in size, diversification, and momentum. Successions of domestic political and economic policies have relegated Brazil's once emerging defense industry to a marginal position in the global defense industry. This article analyzes future prospects, challenges, and growth strategies for Brazil's defense industry.     

Poland's national potential and its international position within the European Union – research remarks

This article examines Poland's national potential and its international position within the European Union (EU) with respect to security issues. It presents research results based on a comparison of Poland's national potential as it relates to other EU countries, which is useful when evaluating Poland's power within the EU. The article also evaluates Poland's crisis potential, i.e. it identifies those factors that may potentially be treated as threats to national and regional security. Finally, it enables the identification of challenges to Poland's security in the second decade of the twenty-first century. The research is conducted according to a multidimensional comparative analysis, which is perceived by the author as the best available to measure a country's power despite its weaknesses.     

The contexts of strategy as a guide for defense planning in the Philippines

Efforts toward developing an independent and credible Philippine defense policy were revived when Benigno Simeon C. Aquino III was elected President of the Philippines in 2010. President Aquino renewed the military modernization program in 2012 and emphasized the necessity of a “minimum credible defense posture.” Given the modernization efforts of the government, this article aims to contribute to the development of the concept of minimum credible defense posture by exploring how theory contributes to defense planning. It argues that the contexts of strategy are useful in planning for national defense because these contexts can provide a conceptual framework for defense planners. It proceeds in three parts: the opening section reviews the literature on defense planning; the second surveys the context of developing strategies as discussed in the General Theory of Strategy; and the last provides a definition of minimum credible defense and applies the context of developing strategies to the case of the Philippines.     

Planning for the next Takur Ghar

The USA is currently facing an increasingly diverse range of threats, including non-state actors, particularly violent extremist organizations attempting to do harm. The national leadership has made it clear that for the near future it will employ Special Operations Forces (SOF) as the tool of choice in short-duration, high-intensity operations that have more in common with the battle of Takur Ghar, than those with a larger footprint. It is critical then that the lessons of the past are learnt now and are applied before employing SOF in the future. This becomes especially important given the short lead-time in concert with the short-duration/high-intensity tempo of their operations. In the Battle of Takur Ghar, during Operation Anaconda, rigid adherence to the joint functions, especially clearer and more robust Command and Control (C2) and Intelligence, Surveillance, and Reconnaissance (ISR) in the planning and execution of Operation Anaconda would have yielded a better operational outcome and saved lives. With the benefit of hindsight, many things could have been done differently, but several key issues stand out. The C2 structure must include all components from the outset to synchronize effects and rapidly re-task ISR. There must be multiple communications redundancies and adequate bandwidth. Finally, all SOF, conventional and interagency capabilities must be synchronized under one task force commander with a sufficiently robust C2 infrastructure to direct the entire effort. As our nation calls on SOF at an ever-increasing rate, we must take those lessons learned and apply them to future operations.     

基于保障时间窗的油料调拨运输模型

通过引入保障时间窗,同时考虑油料保障的时间约束和运力约束,建立了基于保障开始时间最早,并尽可能满足保障需求量的调度模型。针对问题的多目标性,基于理想点法将初始模型转化为单目标优化模型。采用粒子群算法对模型进行求解,并设计了算法编码和求解步骤。通过算例验证了模型和算法的可行性及有效性。     

基于改进粒子群优化算法的微电网孤岛选址定容

分析了在重要孤立系统中采用微电网供电的必要性,在此基础上提出了采用由非支配排序法和拥挤距离排序法改进的粒子群算法进行微电网选址定容,其目的是改进多目标微电网规划问题的优化结果。通过改进算法与基本算法算例结果的对比分析,验证了改进算法在求解孤岛选址定容问题上具有较强的寻优能力、较高的收敛精度和较稳定的最优解,为进一步研究微电网孤岛选址定容问题提供了思路。     

圆柱壳振动声辐射Jacobi-Ritz时域半解析法及特性分析

针对圆柱壳结构瞬态声振特性分析研究不足,结合Newmark-β积分法和Kirchhoff时域边界积分方程,提出一种圆柱壳受迫振动声辐射Jacobi-Ritz时域半解析法。基于一阶剪切变形理论和微元法思想,建立了圆柱壳振动声辐射分析模型,采取Jacobi多项式和Fourier级数表示轴向和周向位移容许函数,基于Rayleigh-Ritz法和Newmark-β积分法计算圆柱壳的受迫振动时域响应,在此基础上,基于Kirchhoff积分方程求解辐射噪声时域响应,分析圆柱壳受迫振动声辐射特性。与有限元方法/边界元方法数值结果对比表明,该方法具备收敛性好、精度高等优点,圆柱壳结构声振响应峰值随边界条件的刚度变弱存在左移现象,振动声辐射响应随厚度的增加呈现下降趋势;当随机载荷峰值频率与结构固有频率接近时,结构声振响应出现强特征线谱。     

多基准站相对定位算法及先验基线向量偏差影响分析

为提高单基准站短基线相对定位解算的可靠性,研究了多基准站约束的相对定位算法。将基准站间可提前测量的先验基线信息融入观测模型中,给出了多基准站相对定位的函数模型和随机模型,在此基础上推导了模糊度精度因子的解析表达式,揭示了基准站数量的增加对模糊度浮点解精度提升的作用;从理论上分析了基准站间先验基线信息中的偏差对模糊度解算的影响,分析表明,当先验基线各分量偏差的绝对值之和小于5 cm时,模糊度解算几乎不受影响;通过仿真和实测数据进行了验证。试验结果表明,增加基准站数量不仅能有效提升模糊度解算成功率和收敛速度,并且对先验基线信息中的偏差具有较好的抑制作用,当基线各分量偏差均增加到4 cm时,实测数据模糊度解算成功率仍能达到92%以上。研究结论为特殊场景下多基准站间的快速非精确标定提供了理论依据。     

空间引力波探测无拖曳技术现状与趋势

航天器无拖曳控制是实现引力波空间探测科学平台超静超稳运行的核心关键技术之一。目前,国内外各研究机构对航天器系统的动力学与控制进行了深入研究,并针对不同的探测频段需求提出了不同的探测任务。根据探测任务进行了航天器编队设计与控制的详细介绍和分析,对涉及的无拖曳与姿态控制、高精度惯性传感器与执行机构等原理和理论方法进行了深入的剖析。针对现已开展的空间引力波探测无拖曳航天器在轨飞行的演示验证整体情况进行详述和分析。在此基础上,提出后续开展相关研究中亟待解决的关键问题,指出未来无拖曳航天器系统动力学与控制的研究热点和趋势。     

装备预研管理数字化转型研究——数字孪生装备预研

数字经济时代,装备预研管理应积极面对数字化转型趋势,构建与数字经济发展相适应的管理体系。结合数字经济的变革属性,借鉴民口科技计划管理数字化实践经验做法,总结和分析当前装备预研管理数字化面临的主要问题及紧迫需求,提出未来装备预研管理发展的一种新范式——数字孪生装备预研,即利用数字孪生助力装备预研管理的数字化转型,并从组成、理想特征和能力、关键技术以及发展路径四个方面对数字孪生装备预研的概念内涵进行了深化阐述,以期对当前装备预研管理的创新起到参考和促进作用。