一个新的组合恒等式及其证明

本文以定理的形式提出一个新的组合恒等式。它是在恒虚警算法研究和性能分析中经常遇到的恒等式。对此,文中给出详细的证明。在证明过程中,我们还提出了有关该定理在实际中可以直接应用的3个引理和2个推论。     

旋转稳定塑料弹体工程设计计算研究

本文以实验结果为依据,首先分析了塑料弹体影响弹丸膛内运动的物理性能,然后结合旋转弹丸的膛内运动特征,经过模拟试验,采用数学拟合法,初步建立旋转稳定弹塑料弹体工程设计计算的数学模型(包括结构尺寸设计计算、强度计算和内弹道计算)。     

‘Winston has gone mad’: Churchill,the British Admiralty,and the Rise of Japanese Naval Power

As Chancellor of the Exchequer during the late 1920s, Winston Churchill was at the center of British strategic decision making about how to respond to the naval challenge posed by Japan's rise as a rival sea power. Churchill downplayed the likelihood of war with Japan. The leadership of the Royal Navy disagreed: they saw Japan as a dangerous threat to the security of the British Empire. Examining this dispute between Churchill and the Admiralty highlights the awkward political, economic, and strategic tradeoffs confronting British leaders between the world wars.     

Troubled triangle: Russia,Ukraine and the United States

A potentially productive triangular arrangement among Russia, Ukraine, and the United States emerged in 1994 from efforts to constrain nuclear weapons diffusion. By 2001, this promising initiative was nearly moribund, owing to the inability or unwillingness of the parties to fulfill the commitments of subsequent agreements. The domestic and external causes of this failure are many and clear. Yet the advantages to each of reengaging in a trilateral relationship are also plain. This means fulfilling their unfinished agenda by learning from past mistakes, adopting realistic premises and goals, and pursuing ‘bottom up’ as well as ‘top down’ strategies.     

The myth of Afghan electoral democracy: the irregularities of the 2014 presidential election

ABSTRACT

This article systematically assesses the 2014 Afghanistan Presidential Election, the first transfer of power from President Hamid Karzai to an elected successor, using provincial voting data as well as explicit data from polling centers. The analysis finds unusual voting results in the April election, where no candidate received 50%+1 votes required by the Afghan constitution, versus the voting results realized for the June ‘runoff election.’ As in other Afghan voting analyses, this article finds voting based on ethno-linguistic preferences, and interestingly found Dr. Ashraf Ghani receiving almost all the swing votes in the runoff election even though the other leading candidate from the April election all endorsed Dr. Abdullah Abdullah. More importantly, however, the research presented here clearly finds extremely strange voting patterns. For example, the polling data center analysis finds 606 polling places where Ghani received all 600 votes and Abdullah received none and another 900 polling centers that gave virtually all its votes to Ghani. These results in combination with other analyses raise the very real possibility that the election results were illegitimate. The article concludes with a discussion of the implications of the research to future Afghan elections and their processes as well as to the long-standing conflict in the country.     

Boost-glide Weapons and US-China Strategic Stability

ABSTRACT

The United States and China are testing boost-glide weapons, long-range strike systems capable of flying at Mach 5 or faster through the upper atmosphere. For the United States, these systems would provide a conventional prompt global strike capability, which, together with US ballistic missile defense programs, Chinese experts regard as a threat to China's ability to conduct nuclear retaliation. This perception is encouraging the Chinese military to modify its nuclear posture in ways that tend to create greater risks for both sides. If China's own boost-glide systems are meant to carry nuclear payloads only, their deployment would not fundamentally alter the current situation between the two states. However, if they were conventionally armed or dual-purpose, or if the United States could not determine the payloads they carried, the deployment of Chinese boost-glide systems could compound problems of strategic stability created by the introduction of ballistic missile defense, antisatellite, and antiship ballistic missile capabilities. If the technical hurdles can be overcome, it may be difficult for the two sides to refrain from these deployments in the absence of strong mutual trust or an established arms-control relationship. New confidence-building measures and expanded mutual transparency are warranted to avoid creating new dangers.