Laser marking system for light guide panel using design of experiment and web-based prototyping

A light guide panel (LGP) is an element of the liquid crystal display (LCD) back light unit (BLU), which is used for display devices. In this study, the laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected. A web-based design tool was developed to generate patterns of light guide panel via the network, and the tool may assist the designer to develop various prototype patterns. Topcon-BM7 was used for luminance measurement of each specimen with 100 mm×100 mm area. By Taguchi method, optimized levels of each parameter were found, and luminance of 3523 cd/cm² and uniformity of 92% were achieved using the laser machined BLU.     

基于FPGA的四相步进电动机控制器的设计

介绍了一种基于FPGA的四相步进电动机控制器的设计方案,给出了其控制原理、相关模块的设计及应用实例。该控制器采用全数字化控制,使用Verilog HDL语言编程,能够实现四相步进电动机的复位、脱机、转速和正反转控制。仿真及应用结果表明,该控制器控制灵活、调速范围大、精度高、运行稳定可靠。     

基于Tesla平台的快速反投影运算

反投影运算是锥束CT图像重建算法中运算量最大,最耗时的部分,是制约重建速度的瓶颈。为此,在计算统一设备架构模型下,应用体素驱动法实现基于Tesla平台的反投影(BP)并行运算,并对BP运算上的访存和数学指令进行优化。实际CT数据的重建结果表明,该方法的运算速度是CPU串行程序的198倍,效率高且易于实现。     

改进的BP神经网络算法在航迹匹配中的应用

利用迭代最近等值点(ICCP)算法对重力图上的航迹进行匹配可以减小惯性导航系统误差,但计算量大。针对上述问题,通过修改激励函数并增加假饱和预防函数,提出一种改进的反向传播神经网络学习算法。仿真结果表明,该算法可以加快搜索最近等值点的速度,更好地满足重力辅助导航对匹配精度及匹配速度的要求。     

基于免疫算法和反向传播神经元网络的无线网络入侵检测研究

为了能够检测到无线网络系统中已知和未知类型的入侵者,提高无线网络系统的安全性,在对网络数据分析和研究的基础上,提出一种基于免疫算法和反向传播神经元网络的入侵检测方法。首先利用免疫算法对网络数据进行预处理,再运用反向传播神经元网络对处理后的数据(程序)进行识别。实验表明用该方法检测无线网络系统中的新型入侵者是可行、有效的,检测入侵者的准确率可达到97%。     

N（2）—乙酰基—9—[（2—乙酰氧乙氧基）甲基]鸟嘌呤的制备工艺条件的研究

人工神经网络由于其具有较好的自组织,自学习,多输入,多输出的能力,在预测方面已取得了广泛应用,本文将BP人工神经网络应用于N（2）－乙酰基－9－[2(2-乙酰氧乙氧基）甲基鸟嘌令的制备工艺条件快速 准确地确定工艺影响参数及其范围的问题。     

Lotka-Volterra捕食系统的反步控制设计

通过反步设计方法,研究了Lotka-Volterra捕食模型的全局稳定化问题,得到了使闭环系统在正平衡点处全局渐近稳定的控制规律,其控制效果通过了数值模拟的验证．     

微型电流互感器在塑壳断路器设计中的应用

该文针对微型电流互感器在塑壳断路器设计中的应用,采用微型电流互感器电阻分流应用方法,针对互感器的非线性设计了微型电流互感器输出数据的自校正实现方法。采用三相交流电压直接降压供电的单电源方式,简化了塑壳断路器的硬件设计。电路短路故障时采用电容储能方式为控制器和脱扣器提供能量,保证了三相交流电路短路没有电能供给时控制器的正常运行和脱扣器的可靠的脱扣。     

A Review of:“Safety in Manual Materials Handling.” By COLIN G. DRURY. (Cincinnati: US Dept. of Health,Education & Welfare, 1978.) [Pp. viii+ 209.]

The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry occurred, and on the posture to which it referred. A quantitative relationship between the forces exerted in different asymmetric postures is discussed, as a basis for formulating universal ergonomic guidelines for optimal working postures. The reduction in force in different asymmetric postures can be explained by length of the muscle, the activation of the muscle, and the moment angle of the muscle.     

Spatial frequencies in aesthetic website evaluations--explaining how ultra-rapid evaluations are formed

This study investigates how aesthetic website evaluations, especially those formed after very brief presentations, depend on visual information that is encoded in low- or high-spatial frequencies. A total of 92 participants took part in the experiment. The study used a 3 × 3 mixed design in which presentation time (50, 500 and 10000 ms) and spatial filtering (low-pass filtered, high-pass filtered and unfiltered stimuli) were manipulated. First, we replicate prior results from online studies of high- and low-spatial frequencies. Second, we confirm a prediction from neurocognitive models that only low-spatial frequencies are relevant to aesthetic judgements in ultra-rapid presentation modes. Third, we demonstrate that stimulus repetitions lead to an overestimation of the importance of ultra-rapid stimulus presentations. Taken together, our results highlight the utility of neurocognitive models of visual processing to explain the rapid aesthetic evaluation of websites. PRACTITIONER SUMMARY: Using neurocognitive models we present an approach to explain how aesthetic impressions are formed. We show that ultra-rapid judgements are connected with low- but not with high-spatial frequencies, which are neurologically processed in different visual pathways. Furthermore we identify possible methodological problems in previous studies of ultra-rapid website perception.