基于圆形滑动窗口的瞳孔定位算法

瞳孔定位是眼动识别中的一个关键步骤.针对目前瞳孔定位算法存在精度低、耗时高、人脸偏转时的定位误差较大等问题,提出了一种通过创建滑动窗口来精确定位瞳孔中心的算法.首先利用CLM模型提取人脸的眼部区域,对提取后的图片进行预处理,然后通过创建圆形滑动窗口对图片进行扫描并计算每个窗口内灰度值的和,利用人眼瞳孔的灰度值相对较低这...     

线纹辨识与特征值提取算法研究

为解决线纹尺的线纹磨损、线纹划痕、摄像头成像失焦、曝光过弱或过强以及线纹尺照射光不均匀等对线纹辨识的影响,提出了一种线纹辨识及线纹中心线特征值提取算法:1)采用区域划分法确定每个线纹灰度极值的位置;2)通过极值加权法提取每个线纹中心线的特征值;3)对线纹中心线上的图像灰度值进行平滑处理后,再搜索线纹中心线端点坐标,并根据端点坐标值大小确定主线纹中心线的特征值。实验表明,所述的线纹辨识及线纹中心线特征值提取算法基本上可以消除上述问题对线纹辨识的影响,且线纹中心线的特征值提取正确。     

引弧板对桥式双断点断路器灭弧性能的影响

合理的引弧板设计可以大幅度提升限流型断路器的开断性能。为此,针对桥式双断点断路器,对比分析了U形槽引弧板的U形槽位置和大小等对灭弧性能的影响。首先,设计了一个带卡住机构的桥式双断点断路器可拆式灭弧室样机,并通过3维有限元电磁仿真和多体动力学分析验证了样机的可行性。然后利用设计的实验样机,通过对比开断波形和开断特性参数,重点研究了3种不同引弧板结构对灭弧性能的影响。研究结果表明:在引弧板上增加U形槽可以增大动导电杆的电动斥力,且较大的U形槽作用更加明显;U形槽的引弧板有利于电弧拉长及进入栅片,增加U形槽后,电弧电压峰值提高了15 V,但是U形槽嵌入栅片容易造成弧根进入栅片后又重新转移到动导电杆上,不利于电弧在栅片中稳定燃烧。研究结果可为断路器的设计提供参考。     

弧柱压降对塑壳断路器限流性能的作用

低压断路器依靠栅片分割电弧成短弧来熄灭电弧,传统的观点认为塑壳断路器限流作用主要依靠短弧的近极压降.从塑壳断路器尺寸紧凑、栅片数受限制出发,提出弧柱压降对限流同样起很大作用.用最新文献中提出的经验公式进行分析,并对一个实际塑壳断路器在带与不带灭弧栅片条件下进行分断试验,测量其电弧电压,说明弧柱压降对限流性能的贡献.用不同触头系统结构的断路器作对比实验,双向斥开的触头系统的分断性能高于单向斥开的触头系统,证实提高弧柱压降是一种有效的限流措施.     

限流式断路器的优化设计

本文对一种工作于交流２４０Ｖ电路中的微型限流式断路器进行了优化设计。应用光纤成为研究短路电流达６ｋＡ时弧根的运动情况，使用计算机软件来处理光纤阵列的图像以便确认灭弧室中弧根的准确位置，由弧根位置一研究电弧朱运动性，最后研究了多种动触头材料及引弧角材料对弧根运动的影响。     

声源辨识个体差异研究

为研究声源辨识中的个体差异,分别针对声源材料和尺寸设计并完成了声音不相似性的2个主观评价实验。实验采用被击板的合成声,通过成对比较法获得声音的不相似性评价,对不相似矩阵进行CLASCAL多维尺度分析,得到被试间差异性规律。结果表明:材料不相似性评价中,被试间的个体差异主要和性别有关;尺寸不相似性评价中,受训并没有增加被试间的差异性。     

ZQF-80kW直流电机能量反馈试验台研究

介绍了ZQF-80kW直流电机能量反馈式试验台的设计.与传统试验台相比,该试验台将被试发电机所发直流电能输送给陪试直流电动机,陪试机与拖动电机一起对被试机进行拖动,构成能量反馈.整个试验台采用带通讯的检测数字显示仪表,利用MCGS组态软件设计操作界面,具有人机界面友好且操作简单方便的特点.     

基于渐消卡尔曼滤波器的永磁同步电机的仿真

使用带渐消因子的自适应卡尔曼滤波构造了永磁同步电机的速度观测器.该滤波器根据永磁同步电机的输出,在线自适应调整渐消因子,从而使滤波器在电机模型存在误差或电机受到外扰的情况下仍收敛并保持最佳,同时具有高收敛速率的特点.最后对基于渐消卡尔曼滤波器的永磁同步电机进行仿真实验.仿真结果表明,该观测器能有效地实现电机的转速观测,具有良好的动、静态特性.     

多端直流输电工程直流高速开关直流燃弧特性试验分析

为了校核多端直流输电工程中直流高速开关偷跳后开关性能,文中结合直流高速开关实际运行工况,在西安高压电器研究院有限责任公司搭建直流高速开关直流燃弧试验平台,以ZKLW-550型开关为试品,国内外首次开展直流高速开关直流燃弧耐受能力试验验证。试验结果表明:ZKLW-550型开关经过DC 4 000 A、持续时间400 ms、共5次的烧蚀,未产生明显的外部效应,满足考核试验要求。研究还发现:直流燃弧试验中高速开关双断口弧压稳定在1 kV左右;动静弧头端部直流烧蚀严重,静弧触头较新触头缩短1.7 mm,重量检测减轻10 g;动弧触头烧蚀变形,无法利用工装正常拆卸动弧触头。文中的研究内容对直流燃弧试验回路设计和多端直流工程中直流高速开关的工程应用具有一定的参考价值。     

基于EOG的扫视角度识别与分类研究

论文对基于眼电信号（EOG）的扫视角度识别算法进行研究。设计了扫视角度定位和EOG采集实验。提出了联合线性预测系数和波形参数的EOG特征描述新方法;并使用BP神经网络与支持向量机对特征向量进行识别和分类。实验结果表明,本文所提出的方法能较好地识别出不同扫视角度的眼动模式。     

Acceleration of Dielectric Charging in RF MEMS Capacitive Switches

To design and validate accelerated life tests of RF MEMS capacitive switches, acceleration factors of charging effects in switch dielectric were quantitatively characterized. From measured charging and discharging transient currents at different temperatures and control voltages, densities and time constants of dielectric traps were extracted. A charging model was constructed to predict the amount of charge injected into the dielectric and the corresponding shift in actuation voltage under different acceleration factors such as temperature, peak voltage, duty factor, and frequency of the control waveform. Agreement was obtained between the model prediction and experimental data. It was found that temperature, peak voltage, and duty factor were critical acceleration factors for dielectric-charging effects whereas frequency had little effect on charging     

Application of an experimental design methodology for economic parameter analysis in an open market environment

Statistical data analysis, through the utilization of experimental design, is a powerful tool commonly used in different areas where uncertainty is a problem, and a great amount of data is available for the analysis. After 10 years of open market experience, the data recorded during the last decade from the electric markets suggest that experimental design can be useful for electrical market data analysis. In this paper, the impact of different factors on the determination of economic parameters such as the spot price in an electric market is analyzed. The analysis is based on the experimental design methodology. The implementation of the proposed methodology is illustrated using simple examples from the Argentinien electric market.     

低感设计对变流器电容纹波电流影响分析与优化

在大功率变流器产品的设计应用过程中,因母排杂散电感的不匹配导致变流器模块支撑电容纹波电流有效值偏大,电容长期工作在超额状态以致损坏。针对上述问题,根据变流器模块不同母排结构建立相对应的数学模型,分析了支撑电容电流偏大的根本原因。通过试验的方法测量提取不同母排结构的杂散电感以指导后续母排的设计。根据理论分析提出了通过优化母排设计、改善控制算法来减小母线支撑电容纹波电流。最后,基于某一变流器平台,通过测量不同试验条件下电容电流纹波,对比分析试验数据以验证所提改进措施的有效性。     

Eyeing a real-time human-computer interface to assist those with motor disabilities

The objective of this study was to design an adaptive, real-time assistive system as an alternate HCI that will give computer access to individuals with severe motor disabilities by means of eye gazing only. It focused on the implementation of an algorithm to smooth out abrupt and unwanted jerky behavior of the mouse cursor due to the saccadic nature of the eye movement via the configuration of an artificial neural network that minimizes the jitter effect based on user characteristics. These characteristics were extracted via the creation of user profiles through an embedded graphical interface.     

中国馆夜景照明浅析

作为世博园区的核心建筑,中国馆以创新的绿色照明解决方案和高品质的产品鼎力实现上海世博会倡导的＂低碳世博＂的理念。本文通过前期照明设计概念的确立,大量现场灯光试验结果,总结分析了中国馆夜景照明的全过程。     

Robust design of electrostatic separation processes

The aim of this paper is to analyze the robustness of the electrostatic separation process control. The objective was to reduce variation in the process outcome by finding operating conditions (high-voltage level, roll speed), under which uncontrollable variation in the noise factors (granule size, composition of the material to be separated) has minimal impact on the quantity (and the quality) of the recovered products. The experiments were carried out on a laboratory roll-type electrostatic separator, provided with a corona electrode and a tubular electrode, both connected to a dc high-voltage supply. The samples of processed material were prepared from genuine chopped electric wire wastes (granule size >1 mm and <5 mm) containing various proportions of copper and PVC. The design and noise factors were combined into one single experimental design, based on Taguchi's approach, and a regression model of the process was fitted. The impact of the noise factors could be estimated, as well as the interactions between the design and noise factors. The conditions of industry application of Taguchi's methodology are discussed, as well as the possibility of adapting it to other electrostatic processes.     

Real-Time Detection of Driver Cognitive Distraction Using Support Vector Machines

As use of in-vehicle information systems (IVISs) such as cell phones, navigation systems, and satellite radios has increased, driver distraction has become an important and growing safety concern. A promising way to overcome this problem is to detect driver distraction and adapt in-vehicle systems accordingly to mitigate such distractions. To realize this strategy, this paper applied support vector machines (SVMs), which is a data mining method, to develop a real-time approach for detecting cognitive distraction using drivers' eye movements and driving performance data. Data were collected in a simulator experiment in which ten participants interacted with an IVIS while driving. The data were used to train and test both SVM and logistic regression models, and three different model characteristics were investigated: how distraction was defined, which data were input to the model, and how the input data were summarized. The results show that the SVM models were able to detect driver distraction with an average accuracy of 81.1%, outperforming more traditional logistic regression models. The best performing model (96.1% accuracy) resulted when distraction was defined using experimental conditions (i.e., IVIS drive or baseline drive), the input data were comprised of eye movement and driving measures, and these data were summarized over a 40-s window with 95% overlap of windows. These results demonstrate that eye movements and simple measures of driving performance can be used to detect driver distraction in real time. Potential applications of this paper include the design of adaptive in-vehicle systems and the evaluation of driver distraction     

Reliability-extrapolation methodology of semiconductor laser diodes: is a quick life test feasible?

The test duration of semiconductor lasers required for Telcordia reliability qualification is usually lengthy. An alternative accelerated life test to validate the reliability design is critical for the timely deployment of new products. In this paper, the results of fitting time-to-failure extrapolations based on experimental data from 500-5000-h measurements are compared. It is shown that, for buried-heterostructure lasers that exhibit gradual performance degradation, the lifetime predictions based on 500-1000-h experimental data are consistent with those based on 5000-h data. For ridge-type lasers, little degradation occurs; hence, an early reliability prediction is less accurate. The determining factors that affect the accuracy of the early reliability predictions are discussed.     

A new amplifier circuit with both practical and tutorial value

This paper introduces an amplifier circuit that is based on the use of current mirrors. The circuit is of interest not only because of its simplicity and performance, but also because of its tutorial value in illustrating integrated circuit design philosophies and practical application of the current mirror     

缓解道路闪光灯导致的视觉失能现象的实验研究

人眼在受到强烈眩光刺激时由于进入人眼的光量太大导致视觉出现短暂的失能和恍惚不清,为能够恢复视觉功能,人眼通过调节瞳孔的面积大小来控制进入人眼的进光量,在瞳孔变化的时间内人眼视觉是基本无效的。本文提出瞳孔变化所需的时间(反应时间)由瞳孔延时时间和瞳孔收缩时间两部分组成,而眩光源的强度和持续时间是影响人眼反应时间长短的主要因素。不同强度和持续时间的眩光对人眼的刺激强度不同,所以人眼的感受强度不同。本文通过实验分析得出眩光持续时间在0.1~0.5 s的范围内时瞳孔的反应时间受到眩光强度的影响不大;眼睛的垂直照度在90~130 lx范围时,人眼对眩光强度的变化较为敏感;当眼睛的垂直照度超过130 lx之后人眼感受强度随眼睛垂直照度的增加变化不大。通过本实验希望为道路闪光灯的持续时间和后期设计缓解闪光灯眩光方案时应注意人眼视觉敏感区间提供理论依据。