脉冲追赶式同步扫描下双基地雷达目标分辨力分析

脉冲追赶式同步扫描过程中,双基地雷达的目标分辨力不仅与雷达参数有关,而且还与脉冲追赶进程密切相关.分析了双基地雷达距离、角度和多普勒分辨力的影响因素,并对其在脉冲追赶情况下的变化规律进行分析,结果表明在每一脉冲追赶扫描周期内,双基地雷达的距离分辨力和多普勒分辨力不断提高,而角度分辨力则有所下降.     

联合国利比里亚特派团之授权任务解析

安理会决议表达联合国的意见或意志,具有强制性和法律效力。以安理会第1509号决议为基础,对联合国利比里亚特派团的授权任务进行解析,并论述利政府和联合国利比里亚特派团面临的挑战和相应办法,利于我维和人员了解特派团任务进展情况,有利于更好地执行使命。     

北斗系统三频载波相位整周模糊度快速解算

北斗导航定位系统播发三个频率观测值,有助于载波相位整周模糊度的快速、准确固定。传统的几何无关模型三频载波相位模糊度固定算法通常采用遍历整数搜索的方法确定载波相位-伪距组合系数,组合后的噪声因子较大,模糊度固定成功率不高。在分析了北斗系统伪距测量误差特性的基础上,给出了加权组合噪声因子的定义及其约束下的最优组合系数的求解方法。采用Hatch滤波提高电离层延时误差实时估计精度,成功固定三组线性无关组合系数对应整周模糊度,进而确定基础整周模糊度。利用北斗系统短基线、长基线实测数据对算法性能进行了验证,实验表明:提出的算法可优化超宽巷、宽巷组合噪声因子20%以上,模糊度固定成功率提高10%~18%左右,30s历元平滑后的基础模糊度固定成功率可达90%以上。     

一种基于部分搜索的GNSS模糊度解算方法

为解决LAMBDA算法搜索策略效率不高的问题,提出了一种基于部分搜索的模糊度解算新方法。该方法的解算成功率接近LAMBDA算法,且只需对最后3维模糊度元素采取搜索策略。同时,通过合理设定搜索椭球的大小和搜索策略;大大提高了搜索效率。通过实验对该新算法与Bootraping算法、LAMBDA算法进行了比较分析,进一步验证了该新算法的有效性。     

Interstate border disputes in Africa: Their resolution and implications for human rights and peace

Many researchers have focused on the role colonialism has played in causing interstate border disputes in Africa. Besides the colonial issue, this paper seeks to investigate what other factors fuel interstate border disputes in Africa and determine how effectively the disputes can be resolved. In recent decades, Africa has been tormented by and is still experiencing numerous interstate border disputes which have serious implications for the disputing states. Some of the disputes are resolved, but violations of human rights and instability still occur in these regions. By analysing the content of some relevant documents and with the use of interviews, this paper reveals that most disputing African states rely heavily on foreign intervention (especially by their erstwhile colonial masters) in the resolution of their disputes. It is argued that African leaders need to be more committed and exhibit better leadership in resolving their border disputes, and that they should always seek the expertise of African forums such as the African Union (AU) before calling for foreign intervention. It is suggested that African leaders and the AU understand the problems of Africans better than anyone else, and they are also the ones mostly greatly affected by these disputes. Thus, there needs to be more of a focus on addressing the root causes of disputes in order to avoid them resurfacing, rather than seeking to merely halt them.     

Explaining the impact of militancy on Iran–Pakistan relations

ABSTRACT

Sectarian militants have for years launched attacks from Pakistan across the border to Iran. Finding sanctuary in a neighbouring country can make the difference between success and failure for militants. Conventional wisdom holds that a lasting transnational militancy challenge would typically create serious interstate conflict. Militancy has triggered armed encounters between Iran and Pakistan. This article argues that despite some tension militancy has resulted in deeper cooperation in the ambivalent dyad. Both states’ overarching security concerns, having exhausted other options, the believed involvement of third-party states, and economic potential, have moderately alleviated negative pressure caused by militancy.     

基于协商的Agent资源冲突消解算法研究

针对分布式规划系统中Agent计划的资源冲突问题,研究了资源冲突的分类;基于Agent协商理论,从资源最优配置的角度,论证了最优的协商策略,提出了可重复利用的不可分享型资源的冲突消解算法,较好地解决了Agent分布式规划中出现的一类资源冲突问题。算例表明,给出的冲突消解算法是有效的。     

ENO格式应用分析

对一类高阶、高分辨率的ENO格式进行了较为详细的讨论。通过一些典型算例的应用和同常用TVD类型格式的比较 ,说明了在计算中采用高阶格式分辨复杂流动结构的优越性。在对格式应用分析的基础上 ,指出了格式应用中需注意的问题。通过定量分析说明 ,高阶ENO格式在计算中 ,不但能够减少网格规模 ,而且能够明显提高计算物理量 ,特别是其导数的计算精度     

英语歧义的理解与修辞功能

基于英语学习者有时候为歧义所困 ,从语义学和语用学的角度讨论了英语歧义的分类、理解和修辞功能 ;通过实例进行研究和分析 ,指出了影响歧义理解的主要因素并提出了相关对策 ;介绍了歧义的积极作用 .