复杂系统故障安全风险评价方法

复杂系统的安全风险涉及面广、影响因素多,因此需要系统的、可操作的方法来指导安全风险的评价过程。在系统的各类安全风险中,故障安全风险是由各种故障导致系统发生事故的风险,是最常见的系统安全问题,因此针对复杂系统的故障安全风险评价开展研究。复杂系统故障安全风险评价需要明确的评价参数和评价方法的支持,为此提出了复杂系统故障安全风险评价的流程、分层次的评价参数体系及评价方法,并通过示例来具体说明故障安全风险的评价过程,为解决复杂系统的故障安全风险评价问题提出了可行的思路。     

基于结构方程模型的作战能力评估方法

由于作战能力指标获取困难,当前的作战能力评估方法更多依赖专家知识,构建的模型往往缺乏足够的说服力。因此,在分析作战效能与作战能力关系的基础上,结合结构方程模型,提出一种从作战效能指标出发,评估作战能力的方法,并以某次反潜作战为背景,进行了实例分析。     

Estimation of the kinetic parameters for thermal decomposition of HNIW and its adiabatic time-to-explosion by Kooij formula

A differential/integral method to estimate the kinetic parameters (apparent activation energy E_a and pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied to study the nonisothermal decomposition reaction kinetics of hexanitrohexaazaisowurtzitane (HNIW) by analyzing nonisothermal DSC curve data. The apparent activation energy (E_a) obtained by the integral isoconversional non-isothermal method based on Kooij formula is used to check the constancy and validity of apparent activation energy by the differential/integral method based on Kooij formula. The most probable mechanism function of thermal decomposition reaction of HNIW is determined by a logical choice method. The equations for calculating the critical temperatures of thermal explosion (T_b) and adiabatic time-to-explosion (t_TIad) based on Kooij formula are used to calculate the values of T_b and t_TIad to evaluate the thermal safety and heat-resistant ability of HNIW. All the original data needed for analyzing the kinetic parameters are from nonisothermal DSC curves. The results show that the kinetic model function in differential form and the values of E_a and A of decomposition reaction of HNIW are 3(1 − α)[−ln(1 − α)]^2/3, 152.73 kJ mol⁻¹ and 10^11.97 s⁻¹, respectively, and the values of self-accelerating decomposition temperature (T_SADT), T_b and t_TIad are 486.55 K, 493.11 K and 52.01 s, respectively.     

广播星历参数星上自主拟合算法

导航星座自主导航要求卫星能自主生成导航电文,针对星载计算机的处理能力有限,引入基于遗忘因子的递推最小二乘估计算法实现快速拟合广播星历。针对导航卫星轨道偏心率近似为0,在数据拟合过程中会导致法矩阵(HTH)奇异的问题,提出基于无奇异变换的广播星历参数拟合算法,引入无奇异轨道根数代替经典开普勒根数,迭代拟合得到改进广播星历参数,再将结果归一化到基于开普勒根数的广播星历参数。利用仿真算例验证了广播星历星上自主拟合算法的合理性。     

Chirp信号参数估计算法性能比较

通过数值仿真定量地比较了三种Chirp信号参数估计算法——解线调法、迭代估计法和局部搜索最大似然法的性能,并定性地比较了算法的运算量。仿真结果表明,在三种算法中,局部搜索最大似然法的估计性能最好,而运算量居中;解线调法运算量最大,但估计性能居中;迭代估计法的估计性能最差,但运算量最小。对于实际系统,应根据不同的估计精度和运算量要求,灵活选择不同的算法。综合考虑估计性能和运算量之间的折衷可以得到结论,在三种算法中局部搜索最大似然法是一种相对较好的选择。     

结构方程模型参数估计的GME方法

提出应用广义最大熵的方法对结构方程模型的参数进行估计,该方法能够处理有限的或者不完全数据。为了验证广义最大熵方法在估计结构方程模型参数时的性能,采用了一个应用于美国顾客满意指数(ACSI)的结构方程模型生成仿真数据,仿真结果表明,与PLS相比,GME方法具有更高的拟合精度和较低的预测误差,在样本数据较少时,表现更为明显。     

基于结构相似度的SAR干扰效果评估方法

传统的合成孔径雷达(SAR)图像质量评价指标没有考虑像素点间的相关性和人眼视觉系统感知特性,导致主客观不一致的现象时有发生。提出了一种主客观相结合评估方法,该方法不仅巧妙地利用了结构相似度(SSIM)作为主客观评价的连接纽带,而且结合局部方差相似度与图像高频信息相对应的特点,通过非线性合并得到了结构相似度的修正模型。仿真结果表明,该方法较之传统评估手段具有明显的优势,不仅能够更好地反映出干扰对图像细节的影响,而且能够与人类视觉系统保持高度一致,进一步提升了整套评估系统的效率和准确率。     

无线传感器网络在海防工程结构健康监测中的应用

海防工程是海军赢得非接触、非对称作战胜利和保存作战潜力的重要硬件基础,将关系到海军作战装备战斗力的发挥,直接影响作战的进程与结局。因此,海防工程结构健康监测系统正成为军内学术界和工程界的研究热点。无线传感器网络由于安装方便、维护成本低和部署灵活等特点,已被广泛应用于各类工程结构健康监测系统中。本文阐述了基于无线传感器网络的海防工程结构健康监测系统提出的背景、基本概念和构成体系,通过模拟部署舰艇洞库结构健康监测系统,协作地实时感知和采集洞库结构信息及环境数据,从而实现海防工程、信息网络和后勤管理的无缝衔接,形成一体化保障能力。     

一种快速解算火箭助飞鱼雷关机点方法

为解决火箭助飞鱼雷射程与关机点计算速度问题,运用Chebyshev正交多项式拟合曲线,提出了一种基于时间或能量关机的计算方法.可根据不同的射程快速解算助飞雷关机点,达到实时控制助飞雷射程的目的,与现有方法相比,计算简洁、迅速.最后给出了关机方法软件的仿真流程,并将该软件应用于某助飞雷仿真系统,论证了该方法的可行性.     

Peace-building or structural violence? Deconstructing the aftermath of Nigeria/Cameroon boundary demarcation

ABSTRACT

There is a great conviction that the International Court of Justice’s ruling in 2002 on the Bakassi boundary dispute between Nigeria and Cameroon, and Nigeria’s decision to obey the ruling may have stopped a fierce inter-state war over the boundary. Indeed, many then ascribed to the whole boundary demarcation process as peacebuilding, disregarding the structural changes marked by the violence of forced migration. This article explores how the boundary delimitation has produced particular sorts of structural violence characterised by state neglect, loss of livelihoods and destitution. Thus, the article argues that although a full-blown war was avoided, the socio-economic conditions of the Nigerian populations on both sides of the border were not adequately considered and guaranteed as part of the peace-building agenda. It further argues that Nigeria, like many post-colonial states with the concentration of developments in major cities, neglects rural and border communities. Thus, the border communities accommodating the former Bakassi residents have further degenerated into ‘ill-governed’ spaces. This article uses structural violence as a framework to analyse the primary and secondary data to provide some deeper insights into the issues of violence being experienced by the local populations living on both sides of the demarcated border.