基于高斯混合模型的无线局域网定位算法

目标定位是无线局域网提供位置服务的基础。该文围绕无线局域网目标定位中的定位精度和实时性2个QoS指标,对基于RSSI的定位技术进行研究,提出一种基于高斯混合模型的无线局域网定位算法。该算法由离线训练和在线定位2个阶段组成,采用GMM对RSSI进行建模,降低了系统定位误差,并减少了定位阶段的运算量,提高了定位的实时性。仿真实验结果表明,该算法具有较好的定位精度和实时性。     

基于事务树的最大频繁项集挖掘算法

针对Apriori算法在寻找频繁项集的过程中需多次扫描数据库、侯选项集过多、支持度计算过于复杂等问题,提出TT-Apriori算法。该算法将事务数据库转化成事务树,通过遍历事务树能直接快速地找到最大频繁项目集。简化支持度的计算,避免对整个数据库的扫描和大量的连接步骤,从而提高挖掘效率。     

基于改进基因表达式程序设计的股票指数预测

介绍基因表达式程序设计方法的基本原理,针对股票指数分析与预测问题,在经典的GEP算法基础上,提出一种基于动态变异算子的改进的GEP算法——IGEP算法,动态变异算子随着进化代数和染色体所含基因数目不同而变化,从而加快了GEP的收敛速度和精确度,对算法进行了复杂度和收敛性分析。设计一种基于IGEP的股票指数分析与预测算法,数值实验结果表明,该算法优于经典GEP算法,具有较广泛的通用性。     

基于移动终端的WLAN快速切换方案

移动终端在AP间切换产生的时延和抖动严重影响实时业务的质量。通过分析移动终端切换的过程和现有的改进方案,提出一种基于动态域值的扫描触发机制,有效地避免移动终端在静止和AP信号较好条件下的cache更新。在STA上实现基于动态域值触发扫描的分片cache的更新算法,该算法在保证cache及时更新的同时降低每次更新cache的开销且能有效减小切换时延。     

基于80C186处理器的多功能实验板的研制

针对近年来飞机含80C186处理器电路板修理现状,为掌握该系列板件的修理能力,迫切需要开展其软件测试技术研究.从封装、类型以及时序分析角度,在对80C186处理器进行系统阐述基础上,设计并研制一块基于80C186处理器的多功能(包括串口通信、并口检测以及定时计数功能)实验板,给出该板的硬件电路图与软件流程框图,并基于汇编语言在QTH-2008PCI开发环境下进行功能调试,实验结果表明其有效性.所做的含80C186处理器的正向设计与软件编程研究工作对于逆向修理含80C186处理器飞机电路板板件有很大帮助.     

基于多信号模型和盲源分离的复合故障诊断方法

利用多信号模型可简明表征系统因果关系以及盲源分离算法可提取系统本源信息的特点, 提出一种新颖有效的复合故障诊断方法. 首先, 针对复合故障下多信号模型出现冗余测试和故障模糊组的情况, 应用盲源分离算法实现测点信息的盲分离, 基于盲信号重建多信号模型的因果结构; 其次, 理论分析了该方法对复合故障具有良好的可诊断性. 轧制过程AGC系统的实验结果表明, 所提出方法对双复合故障和部分多复合故障的隔离和定位准确率可达100%.

     

Never blame the umpire – a review of Situation Awareness models and methods for examining the performance of officials in sport

As sport becomes more complex, there is potential for ergonomics concepts to help enhance the performance of sports officials. The concept of Situation Awareness (SA) appears pertinent given the requirement for officials to understand what is going on in order to make decisions. Although numerous models exist, none have been applied to examine officials, and only several recent examples have been applied to sport. This paper examines SA models and methods to identify if any have applicability to officials in sport (OiS). Evaluation of the models and methods identified potential applications of individual, team and systems models of SA. The paper further demonstrates that the Distributed Situation Awareness model is suitable for studying officials in fastball sports. It is concluded that the study of SA represents a key area of multidisciplinary research for both ergonomics and sports science in the context of OiS.

Practitioner Summary: Despite obvious synergies, applications of cognitive ergonomics concepts in sport are sparse. This is especially so for Officials in Sport (OiS). This article presents an evaluation of Situation Awareness models and methods, providing practitioners with guidance on which are the most suitable for OiS system design and evaluation.     

Robust integrated shift register circuit over clock noises for in‐cell touch applications

This paper proposes an integrated shift register circuit for an in‐cell touch panel that is robust over clock noises. It is composed of 10 thin film transistors and 1 capacitor, and the time division driving method is adopted to prevent the negative effect of display signals on the touch sensing. Two pre‐charging nodes are employed for reducing the uniformity degradation of gate pulses over time. In particular, the proposed circuit connects a drain of the first pre‐charging node's pull‐up thin film transistor (TFT) to the positive supply voltage instead of clock signals. This facilitates to lower coupling noises as well as to clock power consumption. The simulation program with an integrated circuit emphasis is conducted for the proposed circuit with low temperature poly‐silicon TFTs. The positive threshold voltage that shifts up to 12 V at the first pre‐charging pull‐up TFT can be compensated for without the uniformity degradation of gate pulses. For a 60‐Hz full‐HD display with a 120‐Hz reporting rate of touches, the clock power consumption of the proposed gate driver circuit is estimated as 7.13 mW with 160 stages of shift registers. In addition, the noise level at the first pre‐charging node is lowered to ?28.95 dB compared with 2.37 dB of the previous circuit.     

基于不同排序方法的快速霍夫曼编码硬件实现

针对软件霍夫曼静态编码计算量大,而动态霍夫曼编码使得解码器同样复杂的缺点,提出了一种准动态霍夫曼硬件编码器。该编码器每次对一组数据序列进行静态编码,然后将编码并行输出,从而使得编码器具有较高的编码速度,而其延迟时间仅为一次编码过程的总时间。首先,为了充分利用硬件并行特性,分别使用动态排序和静态排序两种排序网络,以适应不同场合的编码需要。然后,使用数据流驱动的硬件二叉树构建和解析结构得到信源符号对应的霍夫曼编码。最后,将储存在FIFO中的输入数据查表并输出。设计结果表明,当使用Nexys4 DDR平台时,该编码器可以工作于100MHz以上的频率,同时具有吞吐高、延迟低、编码效率高和译码器简单的特性。     

低冗余二维码汉字编码研究

随着二维码应用领域的不断扩大,二维码的优化和改进也势在必行。二维码在汉字编码过程中采用定长编码模式,忽略了汉字使用频率对二维码汉字编码效率的影响,存在着较大的编码冗余。采用变长编码算法可以减少高频汉字的编码长度,降低二维码汉字编码的平均编码长度,增加编码容量。首先,结合常用汉字的使用频率,对二维码的汉字编码进行分段处理,分析并制定基于汉字使用频率的变长汉字编码表;其次,在不破坏二维码原有编码结构的情况下,仅对二维码的汉字编码采用变长编码方式;最后,分析并比较二维码定长汉字编码算法和二维码变长编码算法的时间性能和空间性能,给出优化及改进思路。实验证明,二维码变长编码算法可降低二维码汉字编码18.4%的冗余。