数字电视信号定位

分析了基于数字电视信号定位的原理。与CPS定位技术比较,阐述了基于数字电视信号定位的技术特点。     

股权市场环境、投资者监督与公司治理绩效--基于关联信号模型的分析

将市场微观结构方法应用于所有权和控制权分离情形下的公司治理问题的研究,面向的实际运作环境是,投资者从事具有直接价值生产性的监督活动,其同时又利用通过监督活动获得的信息在股票市场中交易被监督公司的股权,借鉴Jain和Mirman的关联信号模型考察拥有大宗股权的投资者的公开市场交易对其内部监督控制行为的影响,得出了投资者的监督水平和公司治理绩效受到股票市场流动性等微观结构因素影响的结论,从而进一步揭示出投资者监督和控制有效运作的外部股权市场环境。     

基于耦合Duffing振子和Van der pol振子系统的微弱信号检测研究

传统的微弱信号检测在检测信噪比较低的信号时效果不理想,基于此提出了一种基于Duffing振子和Van der pol振子的耦合非线性系统,建立了非线性耦合模型,详述了耦合系数对耦合非线性系统的影响。采用Simulink数值仿真的方法,分析了Duffing振子和Van der pol振子耦合非线性系统的动力学行为,阐述了基于相平面变化进行微弱信号检测的工作原理。并且具体分析了耦合系统在色噪声背景下的微弱信号检测效果,取得了很好的效果。     

带保修期的寿命型产品多属性招标采购机制设计——以大型医疗设备为例

产品的期望寿命是重要的质量属性之一,事前不可观察且不可验证,直接对该质量属性进行投标没有意义。针对此问题,以大型寿命型医疗设备招标采购为例,利用拍卖机制设计理论建立了一类具有信号传递功能的多属性招标采购模型。模型确定了最优投标规则,包括设备最优期望寿命投标、最优保修期投标与最优价格支付。模型确立了甄别投标企业技术类型与传递产品质量可靠性信息的机制。研究结果表明:首先该机制满足参与约束与激励相容约束,投标企业分别按自身期望利润最大化进行投标;其次该最优机制能保证企业承诺的保修期与期望寿命正相关,能保证技术类型最高、所提供产品期望寿命最大(保修期最长)的企业中标,并且中标企业创造相对来说最高的社会福利。构造一个算例说明新的多属性招标采购机制在实践中易于操作,是可实施的。当质量指标存在不可观察和不可验证的维度时,相关研究为解决多属性招标采购问题提供了一个新思路。     

Exponentially weighted moving average control schemes with variable sampling intervals

The idea of using non-constant sampling intervals has been of interest in quality control applications since it was first suggested for the “skip-lot sampling plan” of Dodge. Recent interest has focused on the use of variable sampling interval (VSI) control schemes. VSI control schemes use a short sampling interval is given     

Single Attribute Control Charts for a Markovian-Dependent Process

In a production process, sequence of observations related to the quality of a process need not be independent. In such situations, control charts based on the assumption of independence of the observations are not appropriate. When the characteristic under study is qualitative, the Markovian model serves as a simple model to account for the dependency of the observations. In this article, we develop two attribute control charts for a Markovian dependent process: the first is based on controlling the error probabilities; the second is based on minimizing the average time to get a correct signal.

The charts are developed under uniform sampling. Under uniform sampling, the two consecutive samples are far enough apart, so that for all practical purposes, two consecutive samples can be considered as if they are being independent. Optimal values of the design parameters of both the control charts are obtained. A procedure to estimate the values of the in-control parameters is also described. The chart's performance is evaluated using the probability of detecting shift. When we implement the proposed charts for the data simulated under given manufacturing environments, the charts exhibit the desired properties of error probabilities and average time to signal.     

Output Dead-Time in Point Processes

When events of temporal point processes are too close to each other they can be erased by dead-time effects. Among various possible mechanisms of dead-time, the output dead-time is the most important. Dead-time effects modify the statistical properties of point processes and some of these modifications are analyzed in this article. To do so, we note that a point process is defined by the distance between its successive points called life-time which constitutes a discrete time positive signal. The dead-time mechanism is a system which transforms such a signal into another discrete time positive signal. Except in very specific cases this transformation cannot be expressed in closed form. We show, however, that it can be written in a recursive form analogous to the state representation of systems. By using this recursion, various statistical properties of point processes with dead-time are analyzed in computer experiments. In this study, we focus on the probability distribution of the intervals between points and the coincidence function which describes the second-order properties of the point process. For the rare processes where theoretical calculations are possible there is an excellent agreement between experiment and theory.     

组合约束下单一产品信号消费者决策贡献率

信号是制造商面对消费者逆向选择问题所采取的重要手段。只有了解消费者在组合约束下产品属性及其水平的重要性排序,制造商才能针对性运用产品属性对消费者实施信号传递。正交设计实验结果显示,具有信号作用的产品属性在不同产品之间具有相似性,而组合约束下单一产品信号消费者决策贡献率具有较大差异,产品属性水平对消费者效用也会产生不同程度的影响。     

WLAN环境下移动点切换时机选择算法

大型无线局域网环境中移动点在不同AP间进行高速移动时需要进行切换,切换过程产生的延迟会影响无线局域网的服务质量,尤其对于多媒体应用,减小移动点在AP之间的切换延迟是提高无线局域网服务质量的关键。该文提出了确定下一个AP的确认、认证与连接过程开始的最佳距离和最佳接收信号强度的算法,算法结合移动点的移动速度、移动偏移角度等因素来确定最佳切换时机,提高切换成功率,减少切换延迟。算法已在地铁信号系统国产化预研项目中得到应用。     

Adaptive threshold method for peak detection of surface electromyography signal from around shoulder muscles

This paper illustrates the accurate identification of the surface electromyography signal obtained from the shoulder muscles (Teres, Trapezius and Pectoralis) of amputee subjects with three different arm motions (elevation, protraction and retraction). During the acquisition of the signal, a variety of variations (amplitude, frequency and noise) were introduced into the acquired signal which will misguide in the prediction of motion of the shoulder. Therefore, a novel approach has been aimed to adaptively adjust the threshold of Teager energy operator in order to filter the unwanted peaks in the pre-processing stage of the surface electromyography (SEMG) signal. Results show that the proposed approach is accurate and effective in the analysis of biomedical signal where peaks are important to detect without the knowledge of the shape of the waveform. As clinical research continues, these algorithms helps us to process SEMG signal and the identified signal would be used to design more accurate and efficient controllers for the upper-limb amputee.