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871.
针对全球定位系统在信号失锁条件下与航位推算组合导航的系统误差快速累积问题,提出一种基于压缩扩展卡尔曼滤波的同时定位与制图的辅助的全球定位系统/航位推算组合导航方法。该方法利用同时定位与辅助实现运动平台在全球定位系统信号无效时连续稳定导航,抑制航位推算定位误差的累积,并利用全球定位系统定位结果校正同时定位与辅助制图误差,减小地图的不确定性。设计基于压缩扩展卡尔曼滤波的同时定位与辅助/全球定位系统组合滤波器,实现大尺度环境下同时定位与辅助/全球定位系统的实时解算。真实实验数据计算结果分析表明,相对于同时定位与辅助定位结果,同时定位与辅助的全球定位系统/航位推算组合导航可有效提高系统定位性能,使得制图精度提高10m。 相似文献
872.
Romain Esmenjaud 《African Security Review》2014,23(2):172-177
The creation of an African Capacity for Immediate Response to Crisis (ACIRC) is a sign of Africa's willingness to take its destiny into its own hands. Presented as a reaction to the slowness of the development of the African Standby Force (ASF), it is also a response to some of the ASF's conceptual weaknesses. This decision reflects a wish to establish an instrument better equipped to deal with the challenges Africa is facing. Departing from the (sub)regional logic of the ASF results from a desire to take into account the transnational nature of threats, while its enlarged mandate is meant to offer Africa the capacity to intervene in all kinds of conflicts, including by undertaking peace enforcement activities. But the obstacles on the road towards the actual creation and mobilisation of this capacity should not be underestimated. These include material difficulties, but also political tensions, between ‘small’ and ‘big’ states as well as between the African Union and subregional organisations. The risk then is high that the ACIRC, whose announcement came as a reaction to France's intervention in Mali, ends up joining the ranks of the many ‘anti-imperialist’ phantoms haunting the history of the Organization of African Unity/African Union (OAU/AU). Confronted by events considered ‘neocolonial’ initiatives, African actors have indeed traditionally reacted by launching grand projects that never got off the ground. However, by actually establishing this new instrument, they may also demonstrate that times have definitively changed. 相似文献
873.
Malte Brosig 《African Security Review》2014,23(3):225-242
This article presents survey data on the African Peace and Security Architecture (APSA). It focuses explicitly on two aspects: the internal constitution and achievements of the APSA; and coordination and cooperation with external actors, such as Regional Economic Communities, the United Nations and the European Union. The survey, conducted between October 2011 and December 2012, targeted 198 security experts in international organisations, think tanks, academia and non-governmental organisations. It reveals the APSA's current stage of development, achievements and challenges. 相似文献
874.
现行装备器材供应存在着供应渠道过长、不能快速响应等问题,为此通过对装备器材供应链进行集成化体系结构模型设计与构建,探讨了装备器材供应链的重构策略,分别从信息流模式重构、业务流程重构和物流体系重构等3个主要方面对装备器材供应链重构策略进行了分析与探讨,以实现装备器材供应链的快速响应. 相似文献
875.
876.
This study revisits the causal linkages between military spending and economic growth in China and G7 countries (i.e. Canada, France, Germany, Italy, Japan, the UK, and the USA) by focusing country-specific analysis for the period 1988–2010. The panel causality analysis, which accounts for both cross-country dependency and heterogeneity across countries, is employed in this study. Our results find evidence of the neutrality hypothesis for Italy, France, and Germany, the military spending–growth detriment hypothesis for both Canada and the UK, and one-way Granger causality running from economic growth to military spending for China. Furthermore, we find a feedback between military spending and economic growth in both Japan and the USA. Thus, our results do not support that one size fits all. 相似文献
877.
Landau用序参量的幂级数展开来表示相变温度附近的自由能,强调对称性与序参量在相变中的作用.正确书写自由能形式,可以计算可能相的温度曲线,得到关于序参量的方程,从而推知系统的结构. 相似文献
878.
B. Peter Rosendorff 《Defence and Peace Economics》2013,24(5-6):443-457
This paper presents a game‐theoretic model of suicide terrorism containing three agents: the terrorist leader; a targeted government; and potential terrorist supporters. Supporters join the terrorist group if they gain more from their participation than from their economic opportunities. Preemptive measures by the government can result in a backlash that encourages recruitment through new grievances. Suicide attacks can also lead to recruitment. Increases in preemption costs and/or economic opportunities can reduce the overall level of terrorism, while increasing the proportion of suicide to normal attacks. An increase in the effect of preemption on recruitment, or the propaganda effect of suicide bombings has the opposite effect of increasing normal and suicide attacks, but decreasing the proportion of suicide to normal attacks in the terrorist organization’s strategy profile. 相似文献
879.
Sub-Saharan Africa has witnessed the end of foreign colonial rule, the rise and fall of autocratic political regimes, and the disappearance of statist command economies. The challenges were to turn populations into coherent nations owing allegiance to the state; to democratise the state structures that govern these populations; and to liberalise the rules that regulate economic transactions. An important source to assess these prospects are the views and attitudes of ordinary Africans. This essay reflects on the original data derived from a crossnational research project. Nine African states were surveyed between 1999 and 2000. An attempt is made to gather some propositions from the analysis of the data. Many present serious challenges to common wisdom about African politics. It appears that the process of nationbuilding has created coherent political communities with high levels of national identity; that democratising the state in Africa builds on existing indigenous demands from ordinary Africans; and that economic liberalisation proceeds in the face of a mixed set of values about market and state. 相似文献
880.
Todd Sandler 《Defence and Peace Economics》2013,24(3):533-548
This article puts forth collection action as a unifying theme for the conference essays on arms trade, control, and production. For each of these topics, collective action failures are related to group size and group composition considerations. Other issues are also examined including the manner in which individual contributions determine the overall level of the associated collective good ‐ the so‐called aggregation technology of public supply. Based on alternative aggregation technologies, the game‐theoretic underpinnings of these arms issues are explored. 相似文献