RWM&DEWS数据二次压缩算法研究

对柑橘实时水分监控与旱情预警系统中的数据参数进行拟合分析,在探讨SDT和LZW 2种压缩算法的基础上,提出一种二次压缩算法:第1次压缩采用基于SDT算法思想的甲均值方法;第2次压缩采用改进的LZW算法实现.对压缩效果进行测试,仿真实验证明,在相同的硬件和软件环境下,该算法能实时、高效地压缩数据.     

Countering the loss of extended vigilance in supervisory control using a fuzzy logic model

When an operator first detects unusual and/or infrequent or irregular signals in a system, the operator does not need to take any action, but must increase his/her level of attention and be alert for any more serious signals that may confirm a problem with the system. This is referred to as extended vigilance. The purpose of this study was to construct a fuzzy vigilance-measuring model for countering the loss of extended vigilance. The model extends two-valued logic (“Yes” or “No”) to multi-valued logic through fuzzy sets. Then a fuzzy logic alarm was developed by the model for combating the extended vigilance decrement. The first experiment compared the effect of the fuzzy measuring model with signal detection theory (SDT) and discussed the relationship between preliminary and extended vigilance for a simulated feed-water monitoring system. The results indicated that the sensitivity of the fuzzy vigilance-measuring model is better than index d′ and β, and that the preliminary vigilance significantly influences the extended vigilance. The second experiment verified the effect of the fuzzy logic alarm. The results indicated that the effect of the fuzzy logic alarm for combating the extended vigilance decrement is significant. When the preliminary vigilance is poor, an appropriate alarm will improve the extended vigilance. However, if the preliminary vigilance is very poor, the improvement of the extended vigilance will be limited.Relevance to industry: The extended vigilance is a new and important issue in human performance problems in industry, particularly in such areas as air-traffic control, industrial inspection and power plant monitor. The measuring model of vigilance could be applied to develop an alarm for promoting supervisory performance of human and human–machine detectors.     

用Multi-ICE仿真器实现ARM7系统的前期开发

以三星S3C4510嵌入式平台为例，重点讨论了Multi-ICE仿真器和SDT软件包在ARM7系统前期开发中的应用。     

数字电视EPG

EPG——电子节目指南是数字电视中使用率最高的一项业务，本文介绍了EPG的概念、内容、实现方法及在用户端的表现形式，对DVB中的SI表的描述机制也做了说明，并举例分析了EIT表涉及的常用信息。     

ESTA "CAN"网络控制协议的初步研究

ACN,全称为Advantage Network Control(先进网络控制协议),是美国ESTA组织标准工作办公室的网络控制协议组正在建立的一种先进的网络控制标准.     

Evaluating autostereoscopic 3D baseball games using signal detection theory and receiver operating characteristic space

This study investigates the effects of display technique (2D, autostereoscopic 3D), ball speed (138, 140 km/h), and operation time (5, 10, 15 min) on the four outcomes of signal detection theory (SDT) (i.e., hit, miss, false alarm, correct rejection), β, d’, receiver operating characteristic (ROC) space, Simulator Sickness Questionnaire (SSQ), and the iGroup Presence Questionnaire (IPQ). The results indicated that the display technique was significant on the hit rate, SSQ, and IPQ, where a higher hit rate, visual fatigue, and IPQ were found in the 3D technique. The results also showed that the ball speed was significant on the miss rate and d’, where a low miss rate and high d’ were found in the higher speed of 138 km/h. The results further demonstrated that the operation time was significant on the false alarm rate, correct rejection rate, d’, SSQ, and IPQ, with a long operation time being associated with a better performance for every variable, except the SSQ.Relevance to industryFrom the results obtained regarding the ROC space, this study found that the possibility of participants’ misjudgements was low, and the accuracy of this research is considered reliable. The results of this study could serve as a reference for N3DS and game manufacturers in designing future products.     

自动武器闭锁机构三维装配精度分析技术研究

闭锁机构是自动武器的主要工作机构,其装配质量对武器发射可靠性与使用安全有较大影响。目前,自动武器产品的公差分析仍使用传统的线性尺寸链计算方法,而忽视了特征变动和配合间隙对装配质量的影响。通过三维偏差分析技术对闭锁机构装配精度进行预测,提出了特征要素离散化处理的方法,采用矢量坐标矩阵来描述几何特征要素在空间中的位置变动,通过蒙特卡洛模拟法随机抽样进行仿真试验,模拟实际表面的偏移。分析满足约束条件的随机数样本,求解装配偏差累积模型,得到了与实际装配情况一致的结果。通过实例对比分析了尺寸链计算、旋量矩阵法和软件仿真三种方法的特点,验证了该方法的有效性,为自动武器设计制造集成应用的实施提供了参考。     

SDT/S在天然胶配方中的应用研究

研究了SDT/S对天然胶胶料配方各项性能的影响。结果表明：在配方中使用SDT/S,对天然胶胶料起硫化促进作用,为保持原水平的硫化特性,可以适当减少促进剂的用量;可有效提高胶料过硫化条件下的300%定伸应力、扯断强度、邵氏硬度、撕裂性能、磨耗性能,可有效提高正硫化或过硫化条件下的胶料与帘线间的附着力。     

A real-time data compression algorithm for gear fault signals

A flexible, stable and controllable real-time algorithm of Auto-Regressive and Moving Average based on Swing Door Trending (ARMA-SDT) is proposed for the compression of impact-type signals in gear fault detection systems. The Auto-Regressive and Moving Average (ARMA) model is used to predict the variation trend of signal features. To guarantee the adaptability, an empirical equation is proposed to calculate the compression threshold of the Swing Door Trending (SDT). Based on the empirical equation and prediction results, dynamic self-regulation of compression threshold is realized, and the compression error always stays around a preconfigured value. Moreover, an experimental setup and an engineering solution are proposed to verify the usefulness, reliability, and stability of the proposed ARMA-SDT algorithm in data compression.     

Study of Subsonic Flow Over a TOW 2B Missile

The objective of this investigation is to study the subsonic flow over a missile. In this paper, a model of TOW 2B missile is studied. Two computational approaches are being explored, namely solutions based on the Reynolds-averaged compressible Navier-Stokes equations and solutions based on the inviscid flow (small disturbance theory). The simulations are performed at the Mach number of 0.6, 0.7, 0.8, 0.9 and 1.0 at four angles of attack of 2, 4, 6 and 8 degree. Results obtained from analytical simulation are compared with numerical data. It is found that lift and drag coefficients would go up by increasing of the angle of attack and the Mach number. Trend of changes of the results that obtained from the small disturbance theory is roughly as same as the numeric solution.