某型机械滤波器失效分析和对策

某型导弹接收机在进行温度循环高温试验时发生故障,经过排查定位为所使用的机械滤波器失效,即滤波器高温时输出端绝缘电阻降低。该文通过对机械滤波器封装结构、工艺制造流程等方面进行分析,得出机械滤波器的失效原因,并通过有效措施控制该器件失效问题再次发生,有效提高了该器件质量的可靠性。     

Threshold gain properties of lasing modes in ID disordered media optically pumped by femtosecond-lasing pulse

By numerically solving Maxwell's equations and rate equations,a comprehensive calculation on spectrum intensity and spectral widths of three localized modes via different pumping rates in one-dimension...     

Adaptive lossless compression of skeleton sequences

The increasing importance of skeleton information in surveillance big data feature analysis demands significant storage space. The development of an effective and efficient solution for storage is still a challenging task. In this paper, we propose a new framework for the lossless compression of skeleton sequences by exploiting both spatial and temporal prediction and coding redundancies. Firstly, we propose a set of skeleton prediction modes, namely, spatial differential-based, motion vector-based, relative motion vector-based, and trajectory-based skeleton prediction mode. These modes can effectively handle both spatial and temporal redundancies present in the skeleton sequences. Secondly, we further enhance performance by introducing a novel approach to handle coding redundancy. Our proposed scheme is able to significantly reduce the size of skeleton data while maintaining exactly the same skeleton quality due to lossless compression approach. Experiments are conducted on standard surveillance and Posetrack action datasets containing challenging test skeleton sequences. Our method obviously outperforms the traditional direct coding methods by providing an average of 73% and 66% bit-savings on the two datasets.     

Survivable routing in IP-over-WDM networks: An efficient and scalable local search algorithm

In IP-over-WDM networks, a logical IP network is routed on top of a physical optical fiber network. An important challenge here is to make the routing survivable. We call a routing survivable if the connectivity of the logical network is guaranteed in the case of a failure in the physical network. In this paper we describe FastSurv, a local search algorithm for survivable routing. The algorithm works in an iterative manner: after each iteration it learns more about the structure of the logical graph and in the next iteration it uses this information to improve its solution. The algorithm can take link capacity constraints into account and can be extended to deal with multiple simultaneous link failures and node failures. In a large series of tests we compare FastSurv with current state-of-the-art algorithms for this problem. We show that it can provide better solutions in much shorter time, and that it is more scalable with respect to the number of nodes, both in terms of solution quality and run time.     

基于分裂聚合块模式选择的运动估计算法

为了简化H.264视频压缩编码标准中庞大的计算量,提出了一种基于分裂聚合块模式选择的运动估计算法.该算法结合H.264标准7种可变块尺寸模式,利用分裂聚合原理,为帧间运动估计提前确定块模式.保证在图像质量允许的前提下,提高编码效率,为各种多媒体需求的广泛应用奠定基础.     

Optimum component switching for systems that operate and idle

Whilst the selection of optimum redundancy designs, in the presence of opposite failure modes, has received much attention in the literature, the associated problem of optimum management of such redundant systems has hitherto been ignored.This note considers the determination of the optimum switching policy for redundancy designs in terms of a cost formulation which weights each of the two failure modes and allows for a cost associated with the repeated switching of components. The integrated design and switching problem is also discussed. By considering all possible three component series — parallel systems, it is demonstrated that the optimum switching policy is critical in the determination of the optimum redundancy design.     

多层集成电路中缺陷地引起的寄生基板模式

针对多层集成电路中由于共地面开窗引起的寄模问题,通过对比“窗口遮挡”形式和多种背孔阵列抑制寄生模传播效果,发现“窗口遮挡”形式在有效抑制寄生模传播的同时会极大地增加电路损耗,存在最简背孔阵列可以达到抑制寄生模传播的效果。在不改变工艺结构的前提下,“双背孔”和“四背孔”形式可以分别满足200 GHz/300 GHz以下介质膜抑制需求,此时背孔所占面积最小,可以有效减小背孔排列密度,增加电路集成度。     

Deep learning approach for investigation of temporal radio frequency signatures of drones

The omnipresence of drones in the civilian air space has led to their malicious usage raising high alert security issues. In this paper, a deep learning approach to detect and identify drones and to determine their flight modes from the remotely sensed radio frequency (RF) signatures is presented. This work intends to detect the presence of drones using two-class classification, the presence along with identification of their make using four-class classification. And this is further extended to the determination of their flight modes using ten-class classification. It employs the proposed architectures of prominent deep learning classifiers, namely, autoencoder (AE), long short-term memory (LSTM), convolutional neural network (CNN), and CNN-LSTM hybrid model. To procure the relevant information from 227 RF signatures having 100 fragments each, the seven significant temporal statistical features, namely, maxima, minima, mean, variance, skewness, kurtosis, and root mean square, are extracted. In a two-class classification scenario, all considered classifiers perform near to idle, whereas in a four-class classification scenario, CNN performs best, followed by AE, CNN-LSTM, and LSTM, respectively. Moreover, in a ten-class classification scenario, AE far outperforms CNN, followed by LSTM and CNN-LSTM, respectively. The best performance in terms of accuracy and classification time confirms the feasibility of the proposed AE classifier for the three considered drone operations.     

双模式高集成负电荷泵电路设计

提出了一种新颖的双模式高集成开关电容电荷泵。该电荷泵集成高频振荡器、电平移位、逻辑驱动以及4个功率MOSFET开关。与传统电荷泵相比,该电路可以工作在单电源以及双电源两种模式。单电源模式下,输出电压为-VCC;双电源模式下,输出电压为-3×VCC。电路采用0.35μm BCD工艺实现。测试结果表明:室温时,单电源模式和双电源模式下电荷泵输出电流分别为36 mA和80 mA时输出电压分别为-3.07 V和-12.10 V。在-55℃到125℃温度范围内,单电源模式和双电源模式下电荷泵输出电流分别为24 mA和50 mA时输出电压分别低于-3.06 V和-12.35 V。该电荷泵在两种模式下工作特性良好,已应用于相关工程项目。     

集团型财务产品应用组件建模策略研究

对集团型企业财务系统信息化实施的特点及难点,以及对财务管理的需求进行了详细的分析,针对集团型企业三种运营管控模式——财务管控型、战略管控型、运营管控型,提出了财务产品应用组件建模的策略,并分析了该财务产品建模的特点。