基于IGSO卫星的多普勒定位单向授时方法研究

针对导航战、城市或者室内环境中,可见卫星数目小于3颗,用户位置未知时,接收机无法完成授时等问题,并结合我国已有卫星导航系统(北斗和CAPS系统)现状,提出了一种基于IGSO卫星的多普勒定位单向授时方法。该方法通过测量卫星信号的多普勒频移,采用积分多普勒计数计算用户位置,完成单向授时功能。分析结果表明,使用3颗IGSO卫星搭载透明转发器载荷,可使我国领土范围内的定位授时可用性基本达到100%;静态观测用户,长期测量定位精度可达3m以内,授时精度误差小于100ns。由于该方法最少只需观测1颗IGSO卫星信号,这为导航战背景及微弱信号环境下的定位授时服务,提供了新的解决方法。     

Z and other cinematic tales from the 30-year Greek civil war

Greek cinema has documented and debated the civil war and its repercussions under different angles, largely defined by censorship, the general political climate, and cinematic trends. This article, first, offers a retrospective that traces the evolution of Greek cinema's ‘takes’ on the civil war vis-à-vis the political changes. Second, it provides an in-depth analysis of Costas Gavras’s film Z, examining its relevance to Greece and how political conflict, in general, is cinematically depicted. The article argues that Z and Gavras’s cinema have been affected and have affected the Greek political situation. However, while Z has spearheaded an international cinematic genre (political thriller), it had minimal effect on the Greek cinema.     

How not to pay for the war

As a result of allied subsidy and the influence of sunk costs, the marginal cost of the Gulf War to the US was reduced to negligible size. This result is at variance with the Olson‐Zeckhauser thesis that in an alliance “the small exploit the large.” A game theoretic alternative explanation suggests that the relation between allies resembles the game of Chicken, successfully played by the US. The ability to shift the marginal costs of war in the short term raises questions about the possible underestimation of long term effects.     

Economic theorizing of conflict: Historical contributions,future possibilities

This article is organized around two major topics addressed by nineteenth and early twentieth century economists: (1) international economic relations and war and (2) economic activity in the shadow of conflict. My thesis is that an early and neglected reservoir of economic thought on peace and war exists and valuable perspectives on research in defense and peace economics can be gained by tapping into it.     

WHAT ARE THE ODDS?

Nuclear optimists and pessimists disagree on whether the odds of nuclear war are low or high. This viewpoint assesses the odds of nuclear war over the past sixty-six years, exploring three pathways to nuclear war: an international crisis leading directly to nuclear war, an accident or misperception leading to nuclear escalation or nuclear retaliation against an imaginary attack, and a general conventional war leading to nuclear war. The assessment is based on the application of Bayes's theorem and other statistical reasoning and finds that the expected probability of nuclear war during this historical period was greater than 50 percent. This level of risk is unacceptably high. It is therefore urgent that effective measures be taken to substantially reduce the risk of nuclear war.     

IS STUXNET PHYSICAL? DOES IT MATTER?

Cyber-weapons are software and software, at least intuitively, is non-physical. Several authors have noted that this potentially renders problematic the application of normative frameworks like UN Charter Article 2(4) to cyber-weapons. If Article 2(4) only proscribes the use of physical force, and if cyber-weapons are non-physical, then cyber-weapons fall outside the purview of Article 2(4). This article explores the physicality of software, examining Stuxnet in particular. First, I show that with a few relatively uncontroversial metaphysical claims we can secure the conclusion that Stuxnet is physical. In particular, there exist instances of Stuxnet that are both located in space and causally efficacious, and this is very strong evidence for their being physical. Second, I argue that the question of physicality is actually irrelevant for the moral evaluation of an attack like Stuxnet because of its undeniably physical effects. Finally, I argue that some features of Stuxnet should make us optimistic about the prospects for discrimination and proportionality in cyberwarfare.     

Conceptual failure,the Taliban's parallel hierarchies,and America's strategic defeat in Afghanistan

ISAF exists to protect the Afghan constitutional model. This strategic objective will be defeated because the GIRoA model has a conceptual flaw that renders it incapable of delivering governance at the local level (Tier IV). This fatal flaw has enabled the Taliban, by developing parallel hierarchies, to displace GIRoA and establish itself in southern locales as the political authority. The Taliban are fighting a revolutionary war, a Maoist displacement strategy that uses guerrilla tactics to advance a political program. Petraeus and McChrystal failed to recognize the character of war, and believed the Taliban are pursuing an exhaustion strategy. They failed to devise a counter-RW strategy. The ‘Surge’ was doomed ab initio.