军校网络信息安全风险评估研究

介绍了信息安全风险评估的相关概念,分析了军校网络信息安全风险评估中存在的问题,并提出了应对策略,希望能对军校开展网络信息安全风险评估工作提供参考。     

Quality control chart design under Jidoka

We consider design of control charts in the presence of machine stoppages that are exogenously imposed (as under jidoka practices). Each stoppage creates an opportunity for inspection/repair at reduced cost. We first model a single machine facing opportunities arriving according to a Poisson process, develop the expressions for its operating characteristics and construct the optimization problem for economic design of a control chart. We, then, consider the multiple machine setting where individual machine stoppages may create inspection/repair opportunities for other machines. We develop exact expressions for the cases when all machines are either opportunity‐takers or not. On the basis of an approximation for the all‐taker case, we then propose an approximate model for the mixed case. In a numerical study, we examine the opportunity taking behavior of machines in both single and multiple machine settings and the impact of such practices on the design of an X – Q C chart. Our findings indicate that incorporating inspection/repair opportunities into QC chart design may provide considerable cost savings. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

航空发动机叶片的内窥涡流集成化原位检测

目前内窥检测是航空发动机叶片原位检测的唯一方法,但是内窥检测对于叶片裂纹缺陷的检测效果不理想.为此,提出内窥涡流集成化检测技术,使这两种方法的优势互补,实现对航空发动机叶片的原位检测.研制了一种可用于航空发动机叶片原位检测的内窥涡流集成化检测探头,给出了航空发动机叶片的检测实例.检测结果表明:内窥涡流集成化检测技术的缺陷检测能力高,并且可以实现对裂纹缺陷的定量评估,因此较单一的内窥检测更有优越性.具有很高的实际应用价值.     

论推行和完善消防设施定期检测报告制度

针对目前消防设施存在的问题,借鉴日本消防设施点检报告制度,建议推行消防设施定期检测报告制度以解决消防设施完好率低下的问题,并就如何完善消防设施定期检测报告制度提出建议。     

使用噪声干扰器规避主动声自导鱼雷的潜艇机动分析

针对噪声干扰器广泛应用于潜艇反鱼雷作战,分析了潜艇释放噪声干扰器后的机动原则,建立了仿真所需要的鱼雷声学模型和鱼雷机动模型.通过仿真得到了不同潜艇机动方案时潜艇的生存概率,仿真结果为滞艇使用噪声干扰器规避主动声自导鱼雷攻击的机动决策提供了依据.     

潜艇使用自航式声诱饵防御声自导鱼雷模型研究

针对潜艇如何使用自航式声诱饵防御声自导鱼雷,分析了自航式声诱饵的初始航向范围,并建立了相应的防御模型.然后采用线性规划方法,求取最优的潜艇规避角度和诱饵航向.最后时典型态势进行仿真计算,结果表明,采用该方法得出的结果与实际作战基本符合,从而验证了模型的正确性.     

CAN总线在装甲车辆故障诊断与状态检测系统中的应用

针对目前装甲车辆内部设备种类繁多、故障机理复杂且缺乏较为全面的实时在线故障诊断与状态检测手段这一问题,提出了一种基于CAN总线的网络化在线故障诊断与状态检测系统设计方案,进行了CAN总线通信网的短帧应用层协议开发以及系统实现。该系统具有实时数据采集、在线故障诊断和状态检测等功能,且扩展性强。该系统通过了实车试验,测试结果验证了该方案的可行性和系统工作的可靠性。     

A novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise,minimum mean square variance criterion and least mean square adaptive filter

Underwater acoustic signal processing is one of the research hotspots in underwater acoustics. Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing. Owing to the complexity of marine environment and the particularity of underwater acoustic channel, noise reduction of underwater acoustic signals has always been a difficult challenge in the field of underwater acoustic signal processing. In order to solve the dilemma, we proposed a novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), minimum mean square variance criterion (MMSVC) and least mean square adaptive filter (LMSAF). This noise reduction technique, named CEEMDAN-MMSVC-LMSAF, has three main advantages: (i) as an improved algorithm of empirical mode decomposition (EMD) and ensemble EMD (EEMD), CEEMDAN can better suppress mode mixing, and can avoid selecting the number of decomposition in variational mode decomposition (VMD); (ii) MMSVC can identify noisy intrinsic mode function (IMF), and can avoid selecting thresholds of different permutation entropies; (iii) for noise reduction of noisy IMFs, LMSAF overcomes the selection of decomposition number and basis function for wavelet noise reduction. Firstly, CEEMDAN decomposes the original signal into IMFs, which can be divided into noisy IMFs and real IMFs. Then, MMSVC and LMSAF are used to detect identify noisy IMFs and remove noise components from noisy IMFs. Finally, both denoised noisy IMFs and real IMFs are reconstructed and the final denoised signal is obtained. Compared with other noise reduction techniques, the validity of CEEMDAN-MMSVC-LMSAF can be proved by the analysis of simulation signals and real underwater acoustic signals, which has the better noise reduction effect and has practical application value. CEEMDAN-MMSVC-LMSAF also provides a reliable basis for the detection, feature extraction, classification and recognition of underwater acoustic signals.     

声对接阵阵元参数控制

提出对声对接阵阵元参数进行控制,以达到提高声对接阵系统精度的目的,并对由于阵元参数改变而引起对接基阵各个阵元之间的交叉耦合的影响以及阵元的近场声压进行了理论分析和计算机仿真计算,结果证明该方法是有效的.     

利用OH发射谱进行的高温低浓度甲烷着火研究

采用激波管进行低浓度甲烷和空气混合气的着火实验,通过测量压力和OH发射光谱,得到不同工况下的着火延迟,并与甲烷的详细反应机理计算结果作比较。结果表明:不同浓度下甲烷着火延迟的对数与温度倒数呈线性关系,着火延迟随甲烷浓度的降低而减少;贫燃条件下,采用详细动力学机理计算的表观活化能与实验数据拟合较好。