Error Concealment Based on Semantic Prioritization with Hardware‐Based Face Tracking

With video compression standards such as MPEG‐4, a transmission error happens in a video‐packet basis, rather than in a macroblock basis. In this context, we propose a semantic error prioritization method that determines the size of a video packet based on the importance of its contents. A video packet length is made to be short for an important area such as a facial area in order to reduce the possibility of error accumulation. To facilitate the semantic error prioritization, an efficient hardware algorithm for face tracking is proposed. The increase of hardware complexity is minimal because a motion estimation engine is efficiently re‐used for face tracking. Experimental results demonstrate that the facial area is well protected with the proposed scheme.     

基于软件无线电的突发模式8DPSK的全数字化实现

提出了一种软件无线电中频收发机的结构和突发模式 8DPSK解调的实现框架 ,在 8DPSK解调时采用了前向初始参数估计算法 ,并证实了该算法的可行性。     

对某自动驾驶仪可靠性增长的试验研究

对某自动驾驶仪可靠性增长工作进行研究,提出了对现役机载电子设备可靠性增长的一些成功、可借鉴的经验。对增长试验过程中发现的问题和管理方面的不足之处,提出一些建议。     

Quality assessment of SRTM C- and X-band interferometric data: Implications for the retrieval of vegetation canopy height

The Shuttle Radar Topography Mission distinguished itself as the first near-global spaceborne mission to demonstrate direct sensitivity to vertical vegetation structure. Whether this sensitivity is viewed as exploitable signal or unwanted bias, a great deal of interest exists in retrieving vegetation canopy height information from the SRTM data. This study presents a comprehensive application-specific assessment of SRTM data quality, focusing on the characterization and mitigation of two primary sources of relative vertical error: uncompensated Shuttle mast motion and random phase noise. The assessment spans four test sites located in the upper Midwestern United States and examines the dependence of data quality on both frequency, i.e., C-band vs. X-band, and the number of acquired datatakes. The results indicate that the quality of SRTM data may be higher than previously thought. Novel mitigation strategies include a knowledge-based approach to sample averaging, which has the potential to reduce phase noise error by 43 to 80%. The strategies presented here are being implemented as part of an ongoing effort to produce regional- to continental-scale estimates of vegetation canopy height within the conterminous U.S.     

基于TMS320C67xx DSP的软件开发及优化

本文介绍了TMS320C67xx的性能特点，给出了其程序开发流程，并详细讨论了常用的软件优化方法．这些方法有一定的工程应用价值。     

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对三种天然气压缩因子计算方法：经典热力学法、SGERG-88法、SY／T6143—1996法进行了介绍并对计算结果进行了对比，第一种方法的计算精度远不能满足贸易结算的要求，我国现行的第二种计算方法与ISO标准方法相比，在10℃以上的温度范围内基本相符，但在10℃以下的低温段则偏差较大。由此说明，我国目前所实施的计量标准与国际上认可的ISO标准方法之间有较大的偏差；同时，对不需要在线计算的场合，提出了一套基于数据拟合的计算体积修正系数的高精度近似方法，可提高体积计量仪表的性价比。     

Quality of manual data collection in Java software: an empirical investigation

Data collection, both automatic and manual, lies at the heart of all empirical studies. The quality of data collected from software informs decisions on maintenance, testing and wider issues such as the need for system re-engineering. While of the two types stated, automatic data collection is preferable, there are numerous occasions when manual data collection is unavoidable. Yet, very little evidence exists to assess the error-proneness of the latter. Herein, we investigate the extent to which manual data collection for Java software compared with its automatic counterpart for the same data. We investigate three hypotheses relating to the difference between automated and manual data collection. Five Java systems were used to support our investigation. Results showed that, as expected, manual data collection was error-prone, but nowhere near the extent we had initially envisaged. Key indicators of mistakes in manual data collection were found to be poor developer coding style, poor adherence to sound OO coding principles, and the existence of relatively large classes in some systems. Some interesting results were found relating to the collection of public class features and the types of error made during manual data collection. The study thus offers an insight into some of the typical problems associated with collecting data manually; more significantly, it highlights the problems that poorly written systems have on the quality of visually extracted data.     

绕片式冷却器性能计算软件开发

介绍绕片式冷却器性能计算的原理，其软件开发的思路及软件的特点。图2     

A polynomial dynamic system approach to software design for attractivity requirement

Because of the widespread increasing application of Web services and autonomic computing, self-adaptive software is an area gaining increasing importance. Control theory provides a theoretical foundation for self-adaptive software. In this paper, we propose the use of the supervisory control theory of discrete event dynamic systems (DEDS) to provide a rigorous foundation for designing software for reactive systems. This paper focuses in particular on design of software with an attractivity requirement. It studies this problem using the polynomial dynamic system (PDS) model of DEDS. A necessary and sufficient condition for software existence and two algorithms for such software design are presented.     

实用天然气可采储量标定软件的开发及应用

针对天然气的开发特点，优选出了方便实用的可采储量标定方法。以气田开发数据库为基础，采用面向对象的程序设计语言VC＋＋，编制了可采储量标定软件，该软件集数据处理、物性参数计算、可采储量标定、结果输出4个模块为一体，计算快捷、迅速、准确，运行稳定、安全、可靠，提高了天然气可采储量标定的精度和工作效率。