基于模板匹配整帧屏幕视频帧内无损编码方法

当前主流的视频压缩标准,如H.264、HEVC等,主要是针对摄像机拍摄的视频而设计的.而屏幕内容(SC)的视频是由计算机生成的,无噪声,要求更高的压缩效率,同时与摄像机拍摄的视频相比包含更多的结构相似性.提出了一种利用屏幕视频中相似性的模板匹配帧内编码方法,采用由21个像素点组成的模板,以像素点为最小单位对整帧进行模板匹配,并使用哈希函数实现高效的模板查找,最后对残差图像进行熵编码.实验结果显示,与标准的HEVC扩展方法相比,该方法在无损编码上压缩率可以提高一倍,编码时间减小了近一半.      

基于PHM技术的导弹维修保障

为解决传统导弹维修保障方法所存在的问题,加快军队信息化建设,提出了基于PHM技术的导弹维修保障方法。分析了不同维修方式、导弹维修保障及信息化建设与PHM技术的关系,利用PHM技术并结合决策支持的思想,建立导弹健康状态的信息管理系统,初步分析了系统的基本结构组成,并结合实际提出了一些需要重点解决的问题。     

一种星载巴特勒矩阵微放电特性的分析与验证

作为星载雷达发射微波功率合成的关键部件,巴特勒矩阵的微放电性能直接决定了雷达载荷的功率容量。因此,有必要对其微放电特性进行分析与验证。针对该需求,提出了一种用于大功率动态合成网络的星载巴特勒矩阵,并对其在真空条件下的微放电特性进行了分析与验证。第一,提出了一款用于星载雷达的大功率巴特勒矩阵,对其功率合成性能进行了分析。第二,为了对巴特勒矩阵微放电性能进行详细研究,对提出的巴特勒矩阵进行了微放电功率阈值仿真和自由电子分布分析。第三,为了验证分析结果的正确性,对该巴特勒矩阵进行了峰值功率14kW的真空微放电试验,验证了其在大功率真空环境下的微波传输功率容量。提出的巴特勒矩阵性能优良,为未来的星载雷达大功率微波部件提供了理论方法和关键技术支持。     

基于无网格算法的化学非平衡流数值模拟

为了验证AUSMPW+格式在无网格算法的精度等以及无网格算法能否用于复杂化学非平衡流数值模拟中,首先将AUSMPW+格式推广到无网格算法中,给出了AUSMPW+在无网格算法中的具体形式。其次,将无网格算法应用于带化学反应的多组分气体Euler方程的求解,给出无网格条件下求解化学非平衡流的具体过程。最后,对NACA0012跨声速绕流场、高超声速弹丸绕流场、氢气/氧气诱导燃烧流场、球锥高超声速绕流场、楔体斜爆轰流场进行了数值模拟。数值模拟结果与相关文献计算结果和实验结果吻合较好,表明了AUSMPW+格式在无网格算法中表现较高精度。同时,采用无网格算法能较好地模拟复杂化学非平衡流场,正确分辨复杂的物理现象,为化学非平衡流数值模拟提供一种新的算法,拓宽了无网格算法的应用范围。     

非均匀环境下利用单个数据集的STAP算法

对非均匀环境下利用单个数据集的机载雷达空时自适应处理(SDS-STAP)算法进行了研究。针对现有单个数据集类空时自适应算法存在的问题,提出了一种基于对待测数据集进行空时二维滑窗处理的二维幅度相位估计(2D-APES)算法。该算法利用回波的统计信息,不仅放宽了算法处理器对于雷达系统阵元数与脉冲数选取的约束,而且能够有效抑制杂波及待测单元内的干扰,同时降低了处理器的计算复杂度。最后,仿真数据及实测数据实验验证了所提算法的正确性与有效性。     

Evaluation and improvement of coastal GNSS reflectometry sea level variations from existing GNSS stations in Taiwan

Global sea level rise due to an increasingly warmer climate has begun to induce hazards, adversely affecting the lives and properties of people residing in low-lying coastal regions and islands. Therefore, it is important to monitor and understand variations in coastal sea level covering offshore regions. Signal-to-noise ratio (SNR) data of Global Navigation Satellite System (GNSS) have been successfully used to robustly derive sea level heights (SLHs). In Taiwan, there are a number of continuously operating GNSS stations, not originally installed for sea level monitoring. They were established in harbors or near coastal regions for monitoring land motion. This study utilizes existing SNR data from three GNSS stations (Kaohsiung, Suao, and TaiCOAST) in Taiwan to compute SLHs with two methods, namely, Lomb–Scargle Periodogram (LSP)-only, and LSP aided with tidal harmonic analysis developed in this study. The results of both methods are compared with co-located or nearby tide gauge records. Due to the poor quality of SNR data, the worst accuracy of SLHs derived from traditional LSP-only method exceeds 1?m at the TaiCOAST station. With our procedure, the standard deviations (STDs) of difference between GNSS-derived SLHs and tide gauge records in Kaohsiung and Suao stations decreased to 10?cm and the results show excellent agreement with tide gauge derived relative sea level records, with STD of differences of 7?cm and correlation coefficient of 0.96. In addition, the absolute GNSS-R sea level trend in Kaohsiung during 2006–2011 agrees well with that derived from satellite altimetry. We conclude that the coastal GNSS stations in Taiwan have the potential of monitoring absolute coastal sea level change accurately when our proposed methodology is used.     

学生成绩随机后台查询系统

本文分析了ＷＩＮＤＯＷＳ９５的通信体系结构,并将ＶＩＳＵＡＬ ＶＯＩＣＥ ＦＯＲ ＴＡＰＩ控件,通过ＶＩＮＤＯＷＳ９５支持的ＯＬＥ（对象的链接与嵌入）机制,将它嵌入到由ＶＩＳＵＡＬ ＢＡＳＩＣ开发的应用程序中,从而实现了学生成绩随机后台查询。     

Digital fixed-frequency hysteresis current control of a BLDC motor applied for aerospace electrically powered actuators

In the conventional cascade control structure of aerospace electrically powered actuators, the current (or electromagnetic torque) loop plays a critical role in realizing a rapid response for a digitally controlled BrushLess Direct Current (BLDC) motor. Hysteresis Current Control (HCC) is an effective method in improving the performance of current control for a BLDC motor. Nevertheless, the varying modulating frequency in the traditional HCC causes severe problems on the safety of power devices and the electromagnetic compatibility design. A triangular carrier-based fixed-frequency HCC strategy is expanded by relaxing the constraints on the rising and descending rates of the winding current to advance the capability of HCC to realize fixed-frequency modulation in the steady state. Based on that, a new flexible-bound-size quasi-fixed-frequency HCC is proposed, and the range feasible to realize fixed-frequency modulation control can cover the entire running process in the steady state. Meanwhile, a corresponding digital control strategy is designed, and four digitalization rules are proposed to extend the capacity to achieve fixed-frequency modulation control to the unsteady working state, that is, a novel fixed-frequency modulation is realized. Simulation and experimental results prove the effectiveness of this improved fixed-frequency HCC strategy.     

光纤开关网络模块高速电路的设计与实现

讨论了FC（Fiber Channel）开关网络模块高速电路的设计与实现。开关网络模块的数据传输速率达到了1.0625 Gbps,其高速电路设计已成为系统能否可靠运行的关键因素之一。分析了传输线选择、特性阻抗控制以及信号完整性等问题,并阐述了布局、布线、电源地和叠层等设计方法。     

高强度钢Domex700MCD焊接性能研究

分析了Domex700MCD焊接性,并通过试验及数据分析表明,在焊接工艺中,采用混合气体保护焊、低合金结构钢焊丝ER69-3,通过控制焊接线能量,运用合理的焊接规范,可获得良好的焊缝机械性能。