A belief-rule-based inventory control method under nonstationary and uncertain demand

This paper is devoted to investigating inventory control problems under nonstationary and uncertain demand. A belief-rule-based inventory control (BRB-IC) method is developed, which can be applied in situations where demand and demand-forecast-error (DFE) do not follow certain stochastic distribution and forecasting demand is given in single-point or interval styles. The method can assist decision-making through a belief-rule structure that can be constructed, initialized and adjusted using both manager’s knowledge and operational data. An extended optimal base stock (EOBS) policy is proved for initializing the belief-rule-base (BRB), and a BRB-IC inference approach with interval inputs is proposed. A numerical example and a case study are examined to demonstrate potential applications of the BRB-IC method. These studies show that the belief-rule-based expert system is flexible and valid for inventory control. The case study also shows that the BRB-IC method can compensate DFE by training BRB using historical demand data for generating reliable ordering policy.     

基于TS201系列DSP的PGA算法实现

相位梯度自聚焦(PGA)算法被广泛用于机载合成孔径雷达(SAR)成像中.由于其过程复杂,数据处理量大,为满足机载SAR实时处理的要求,选用具有强大处理能力的TS201 DSP.为了充分发挥TS201的性能,利用PGA原理和TS201处理器的特点,对算法流程进行优化,并且对最耗时的FFT采用了汇编语言实现,使得运算量和处...     

Measuring the degree of eyestrain caused by watching LCD and PDP devices

In this paper, we propose a new way of measuring the degree of eyestrain caused by watching LCD (Liquid Crystal Display) and PDP (Plasma Display Panel) devices. In the experiments, we used a head-mounted eye capturing device and an illumination setup that was designed to avoid specular reflections caused by glasses or contact lenses. Using the captured eye images, we analyzed the eye blinking and changes of pupil sizes (pupil accommodation), using a real-time image processing algorithm. Then we analyzed the degree of eyestrain based on the calculated blinking rate and the pupil accommodation speed. The proposed method offers five improvements over previous methods. First, we perform a comparative analysis of LCD and PDP devices based on the degree of eyestrain. Second, to analyze the degree of eyestrain, we use quantitative data such as the blinking rate and the pupil accommodation speed. Third, we measure the accurate eye blinking and changes of pupil sizes by using high-resolution and zoomed eye image sequences. Fourth, since the camera and illuminative system are based on a specular reflective model, the proposed method can be used with subjects that wear glasses or contact lenses. Fifth, the proposed method is performed at real-time speed.Experimental results showed that the degree of eyestrain when watching LCD devices was greater than that when watching PDP devices.

Relevance to industry

In the large display industry, LCD and PDP devices have become more and more prevalent. In the past, LCD devices have been compared to PDP devices in terms of factors such as spatial resolution, brightness, contrast levels, etc. To perform more accurate comparisons based on human factor, we are proposing a new way of comparing LCD to PDP devices based on the degree of eyestrain.     

基于SIMD指令的柔性物体并行碰撞检测

复杂场景中柔性物体间的碰撞检测依然难以满足交互设计的要求.为了提高处理速度,文中给出了一种充分利用现代CPU的并行处理能力的碰撞检测算法.算法基于两方面的并行处理:即基于SIMD指令的指令级并行处理和基于多线程的任务级并行处理.算法给出了一种针对SIMD指令特别优化的k-DOP模型--SIMD-DOP,从理论上分析了该包围盒的高效性,并与常规的16-DOP和24-DOP进行了运行效率对比.通过使用SIMD-DOP同时在多核间进行负载均衡,算法获得了优化的并行加速.文中算法已经在一台16核工作站上针对一组复杂测试场景进行了验证.     

八通道可变增益高速数据采集系统

针对多通道超声波应用提出了一种USB+FPGA+DSP的架构,模拟前端可实现8通道高速数据采集,并可实现线性增益和可变采样率。FPGA为系统的控制核心,同时进行信号预处理方面的工作,而DSP着重于复杂算法的应用。最后通过已知信号对整个系统进行测试,验证了该系统性能良好,具有很高的实用价值。     

嵌入式平台下的RFID数据处理终端

介绍一种以AT91SAM9260处理器和Linux嵌入式操作系统为平台的RFID信息采集与处理系统。该系统充分利用AT91SAM9260芯片丰富的标准接口资源,集门禁、考勤、监控为一体,以Linux操作系统为软件平台,完成了RFID数据信息和USB摄像头照片数据的采集、保存与TCP/IP远程数据传输等。介绍了系统的硬件组成原理、软件设计方案和实现方法,为射频识别技术在智能一卡通系统中的应用提供了一种先进的解决方案。     

应用于开关电源的CMOS电流控制振荡器

提出了一种结构简单的CMOS电流控制模式振荡器。该电路利用系统内部参考电压和外接电阻产生的电流信号对电容进行充放电,通过调节外接电阻大小,振荡器输出频率在660 kHz～4.15 MHz内可调。     

The impact of media on collaborative learning in virtual settings: The perspective of social construction

This study examines an alternative function of information sharing – social construction of meaning. Drawing on social construction, social interaction, and task closure theories, we explored the influence of both the media environment in which students are situated and the medium that group members choose to communicate with one another on the intricate relationships among breadth of information sharing, depth of information sharing, and performance of computer-supported collaborative learning (CSCL). A total of 126 students participated in the experiment – including 63 students (15 groups of four students and one group of three students) in the control and experimental groups respectively. Our findings show that most of the proposed hypotheses are supported. Intersubjective interpretation underlies groups information sharing and plays a key role in student learning performance. Evidence shows that when facing a relatively complex task in multimedia environments, students who choose to utilize a medium lower in social presence (i.e., electronic information sharing) are more likely to achieve task closure than a medium higher in social presence (i.e., verbal information sharing). This in turn leads to higher learning performance. The implications for both theory and pedagogy are also discussed.     

Asynchronous double-precision windows based unmanned aerial vehicle real-time path planning

A real-time path planning approach based on asynchronous double-precision windows is proposed for unmanned aerial vehicles (UAVs). In this proposed method, cursory paths and elaborate paths are planned respectively in the global and local windows. Specifically, global cursory path planner and local elaborate path planner are integrated by rolling two windows on different frequencies with different modes. Simulation results demonstrate that the proposed approach is effective for realizing a balance between t...