材料电导率对混响室场性能影响的仿真研究

混响室作为一种经济有效的新型电磁兼容检测设备,近年来倍受人们的关注。在混响室的设计过程中,材料的选择是其中的关键环节之一。通过仿真计算,从电场强度大小和电场均匀性两个方面研究了四种不同电导率材料对混响室场性能的影响。数据结果表明,随着材料电导率的升高,混响室内电场强度的各分量最大值和电场强度平均值均明显提高,并且材料电导率的变化不改变室内电场的分布情况。从电场均匀性方面来看,四种不同电导率材料的混响室,其电场均匀性均满足标准IEC61000-4-21的要求。     

基于几何算法的水下航行器路径规划

在分析水下航行器路径规划影响因素及主要障碍物特点的基础上,提出了一种基于几何算法的水下航行器路径规划算法,并采用该算法对障碍物进行建模和路径规划研究,解决了水下航行器航经多障碍物海区的路径规划问题.最后,通过仿真试验验证了该算法的准确性与可行性.     

The South African Denuclearization Exemplar

ABSTRACT

South Africa's nuclear disarmament is a unique historical case, notable in part for the dramatic shift from deception to cooperation. The unprecedented transparency it demonstrated in order to convince the international community of the veracity of their disarmament is heralded as an exemplar for verifiable denuclearization. Less known is how this case affords insights into how a nuclear weapon program can be clandestinely hidden by the ambiguity provided by an otherwise completely legitimate, peaceful, nuclear energy program. Using a variety of open sources, including newly declassified internal South African and US government reports, it can be shown that South Africa employed a variety of deceptive tactics before it disarmed, and even for nearly two years after becoming a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons. This article reviews that information to derive instructive lessons on the lengths that a nuclear proliferant state might go to conceal its true capabilities and intentions, and to thwart international discovery of the existence and full extent of an existing—or, in this case, a former—nuclear weapon program.     

Reflections on Transparency and Monitoring under the 1993 United States-Russian Federation Highly Enriched Uranium Purchase Agreement

ABSTRACT

The 1993 Highly Enriched Uranium (HEU) Purchase Agreement between the United States and Russian Federation is often described as one of the world's most successful nuclear nonproliferation programs. In 2013, the two states achieved the agreement's major goals of downblending 500 metric tons of Russian weapon-origin HEU to low enriched uranium (LEU) and delivering all resultant LEU to the United States. At one time, the LEU delivered under the agreement generated nearly 10 percent of all electricity in the United States. The agreement achieved its nonproliferation goals through a unique government/industry partnership. Commercial executive agents contracted for the annual sale and delivery of downblended LEU, while the US and Russian governments exercised reciprocal transparency monitoring measures to demonstrate that all LEU delivered under the agreement was derived from Russian weapons-origin HEU, and that the same LEU was used for exclusively peaceful purposes in the United States. The commercial development, negotiations, and implementation of the agreement have been well documented. This article describes the scope of US transparency monitoring activities in Russian HEU processing facilities, as well as Russian monitoring in the United States. In addition, it discusses the results of twenty years of reciprocal transparency monitoring and data analysis, and outlines lessons learned that are potentially applicable to future transparency monitoring and verification regimes and similar cooperative efforts.     

无人集群体系设计与仿真评估方法

无人集群作战正在成为一种改变战争形态的新型作战样式.针对当前无人装备试验相对独立、缺乏一体化闭环设计与集成验证手段的问题,提出了一种体系设计与仿真评估方法.该方法包含了作战概念建模与需求分析、体系设计理念与体系设计、内场仿真实验与方案探索、体系原型研发与评估优化、外场集成试验与综合决策五个阶段,创新发展了体系设计、仿真试验、评估优化的理论方法、工具链路、集成环境,为无人集群的体系化、智能化、实战化提供了一定的理论与技术支撑.     

YHFT-DX处理器全定制EDA技术的开发与应用

在YHFT-DX处理器的研制中,研究并实现了多项支撑全定制设计的EDA技术。针对全定制设计的功能验证,研究并实现了层次式功能模型自动提取技术,能够将晶体管级网表转化为等效的RTL级网表。研究并实现了晶体管级混合时序分析方法,可自动分析全定制设计的延时,并采用多线程并行的方法获得了约10倍左右的速度提升。为提高模拟结果分析的效率,开发了一个延时提取的工具Aimeasure。开发了两个信号完整性分析工具PNVisual和NoiseSpy,分别用于全定制设计的IR-Drop分析和噪声分析。上述技术已在YHFT-DX处理器的设计中得到了广泛应用,有效提高了全定制设计的效率与质量。     

多核处理器验证中存储数据错误快速定位机制

提出并实现的一种数据错误快速定位机制(Fast Fault Location Mechanism,FFLM)面向多核处理器存储系统的功能验证,FFLM基于硬件仿真器构建多端口存储器黄金模型,通过在仿真过程中实时监控存储系统与处理器核之间的访存报文,在线比较被测系统访问真实存储器的数据与黄金模型中的对应数据是否一致,在错误数据从存储系统送入处理器核的时刻就能够发现数据错误。与传统方法相比,FFLM具有仿真速度快、硬件资源代价低以及定位错误时间短的优点。对自主设计的CMP-16多核处理器进行仿真时的统计数据表明:使用FFLM后定位数据错误的速度能够比未使用FFLM时平均提高6.5倍。     

求解布尔不可满足子式的消解悖论算法

求解布尔不可满足子式在超大规模集成电路设计与验证领域都具有非常重要的理论与应用价值,帮助EDA工具迅速定位错误与不一致。针对求解不可满足子式的非完全方法,提出了消解悖论与悖论解析树的概念,在此基础上提出一种启发式局部搜索算法。该算法根据公式的消解规则,采用局部搜索过程直接构造证明不可满足性的悖论解析树,而后递归搜索得到不可满足子式;算法中融合了布尔推理技术、动态剪枝方法及蕴含消除方法以提高搜索效率。基于随机测试集进行了实验对比,结果表明提出的算法优于同类算法。     

C~3I系统中软件的程序设计方法问题

软件的可靠性是Ｃ￣３Ｉ系统成败的关键之一,用规范和程序分离的办法设计软件,其可靠性无法得到保证。该文阐述了应研究形式化程序设计方法的意见,以及目前在这一领域尚存在的困难和解决的途径。     

GETTING BETTER ALL THE TIME

Detect and Deter: Can Countries Verify the Nuclear Test Ban?, by Ola Dahlman, Jenifer Mackby, Svein Mykkeltveit, and Hein Haak. Springer, 2011. 279 pages, $129.