N+1式高频电力开关电源设计

探讨了N＋1式高频电力开关电源的组成和工作原理。开关电源由监控模块和整流模块组成,重点研究了均流技术和开关电源的抗干扰措施,论述了整流模块数量N＋1的选择。实际运行证明,N＋1式高频电力开关电源工作可靠,达到了预期效果。     

坦克发动机技术状况的两种模糊诊断模型

提出了诊断坦克柴油机技术状况的模糊综合模型和模糊模式识别模型。对59坦克柴油机的技术状况进行了诊断计算,证实了这两种模型的实用性和可靠性。     

基于单片机控制的PWM功率放大器的设计

指出了研究新型功率放大器的意义,提出了单片机控制的PWM功率放大器的设计思想,在对PWM功率放大器进行建模的基础上,设计了电流调节器,给出了数字控制算法,实现了单片机控制。PWM功率放大器的研究将为伺服系统的数字化提供新思路,为提高伺服系统的技术性能提供新方法。     

高比重钨合金的烧结成形与组织性能研究

采用液相烧结成形工艺制备了90W-Ni-Fe合金棒,通过分析烧结态钨合金的组织形貌和力学性能,观察合金的断口组织形貌,研究了烧结工艺对高比重钨合金组织性能的影响,认为减少W-W界面,增加W-W界面的结合强度,是提高烧结态钨合金力学性能的有效途径。     

A standardized scan statistic for detecting spatial clusters with estimated parameters

The scan statistic based on likelihood ratios (LRs) have been widely discussed for detecting spatial clusters. When developing the scan statistic, it uses the maximum likelihood estimates of the incidence rates inside and outside candidate clusters to substitute the true values in the LR statistic. However, the parameter estimation has a significant impact on the sensitivity of the scan statistic, which favors the detection of clusters in areas with large population sizes. By presenting the effects of parameter estimation on Kulldorff's scan statistic, we suggest a standardized scan statistic for spatial cluster detection. Compared to the traditional scan statistic, the standardized scan statistic can account for the varying mean and variance of the LR statistic due to inhomogeneous background population sizes. Extensive simulations have been performed to compare the power of the two cluster detection methods with known or/and estimated parameters. The simulation results show that the standardization can help alleviate the effects of parameter estimation and improve the detection of localized clusters. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012     

Life distribution analysis based on Lévy subordinators for degradation with random jumps

For a component or a system subject to stochastic degradation with sporadic jumps that occur at random times and have random sizes, we propose to model the cumulative degradation with random jumps using a single stochastic process based on the characteristics of Lévy subordinators, the class of nondecreasing Lévy processes. Based on the inverse Fourier transform, we derive a new closed‐form reliability function and probability density function for lifetime, represented by Lévy measures. The reliability function derived using the traditional convolution approach for common stochastic models such as gamma degradation process with random jumps, is revealed to be a special case of our general model. Numerical experiments are used to demonstrate that our model performs well for different applications, when compared with the traditional convolution method. More importantly, it is a general and useful tool for life distribution analysis of stochastic degradation with random jumps in multidimensional cases. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 483–492, 2015     

加油机器人操作臂设计及运动学研究

为减少污染和节省人力,使用加油机器人代替人力完成加油工作成为未来发展的必然趋势。为此,专门设计一种加油机器人操作臂的结构形式,在D-H坐标系中建立四自由度加油机器人操作臂的运动学模型,采用变换矩阵方法求解该操作臂正、逆运动学解析表达式,并运用Matlab软件的机器人工具箱对该操作臂正、逆运动学方程进行仿真验证。研究结果证明正、逆方程运动学方程解的正确性以及设计方法的可行性。     

靶场试验遥测数据实时处理软件技术

新研弹药产品靶场试验,被试产品往往装有遥测设备,对试验全过程进行测量和监控,被测参数通过遥测发射设备发送至地面接收站,实时处理遥测数据,发现异常,为保证试验安全、现场指挥决策和后期技术分析提供科学依据。本文提出了遥测数据实时处理的一般要求及实现的一般过程和方法,并对关键算法进行了描述。     

液化石油气贮罐过量充装的危险性分析

根据传热学有关原理,分析了液化石油气过量充装后在贮存、运输过程中受热的危险性。     

图像配准参数的自适应求取方法

提出了一种可见光和红外图像的自动配准方法 .针对多数配准过程需人工干预的问题 ,建立二维仿射变换模型 ,以图像边界为特征 ,以目标边界互相关函数最大为原则 ,对二维仿射变换模型自适应搜索求取最佳配准参数 .给出了实际可见光和红外图像配准的实验结果