一种可适应自然头动的视线 追踪系统的研制及应用

 提出一种适用于单相机的非穿戴式实时视线追踪新方法,并实现了一套样机系统.为提高视线追踪对使用者头动的适应性,提出一个头动自适应视线方向实时计算方法(ARGCMH).方法包含三个计算模型,它们在一套决策算法的控制下相互协调配合,实现视线追踪在一定范围内对头动的自适应,同时保持了适当的追踪精度和速度.实际测评给出了系统主要性能指标,并用一应用实例展现了系统的应用潜力.     

基于视线追踪的眼控鼠标设计

以Visual Studio为平台,OpenCV计算机视觉库为基础,辅助以单片机、传感器、无线传输模块等自主研发了一套头戴式视线追踪系统,完成瞳孔提取、视线追踪定位、眨眼检测等功能,实现眼球替代鼠标完成对电脑的指令。创新性地提出了椭圆拟合与积分投影去噪法等方法,以消除头部微小移动对定位带来的影响,使系统具有较高的精确度和良好的实用价值。     

我国眼动追踪技术在多媒体学习中的应用——2016-2019相关研究的综述

近年来,眼动技术为研究者提供了直接观察学习者认知加工过程的途径,应用于多媒体学习研究领域的程度提高。本文通过对2016-2019年文献研究总结,揭示眼动追踪技术在多媒体学习研究的应用。在分析了眼动追踪技术的优势与局限的基础之上,最后针对眼动指标在多媒体学习研究中的应用提出了建议。     

第三方追踪的安全研究

第三方追踪可以获得用户的浏览历史等隐私信息,如何保护第三方追踪带来的隐私威胁问题成为安全领域的重要研究内容.首先介绍第三方追踪的基本概念、特点及安全现状,并结合第三方应用的类型,总结了第三方追踪存在的隐私威胁.然后从有状态追踪和无状态追踪2个方面介绍第三方追踪的技术,并对第三方追踪防御的相关研究进行了分析和比较.最后总结第三方追踪中研究领域的开放性问题和发展方向.     

基于USB3.0传输的人脸识别近红外相机系统

基于常用人脸识别系统的工作原理,探讨了基于USB摄像头产品现状与红外摄像机应用现状。提出了一种适用于人脸识别、虹膜识别、视线追踪、疲劳驾驶检测等领域近红外相机设计方案。该系统基于USB3. 0传输及全局曝光的COMS图像传感器设计实现,完成了对应的方案设计并进行了简单的效果验证。     

多天线的空时处理技术在CDMA系统中的应用

本文介绍了无线通信中的多天线与空时处理技术,分析了多天线技术的原理和应用。文章追踪了空间通信领域的一些最新动态,在最后介绍了空时编码技术。     

基于无线传感器网络的目标追踪技术

无线传感器网络随着目前互联网技术、计算机技术还有无线通信技术的发展和推广,逐渐被越来越多的利用到了现实的领域中。由于传感器本身具有体积小、功能消耗低等特点,因此无线传感器网络的目标追踪技术目前成为各国都在研究的重要技术。本文分析了目标追踪技术的主要研究意义和背景,并介绍了基于无线传感器网络的目标追踪主要用到的技术。     

RFID技术及其所面临的挑战

无线射频识别(RFID)是利用射频通信实现的非接触式自动识别技术,可工作于各种恶劣环境,通过附着在物体上的标签,能迅速识别多个高速运动的物体。由于它的快速识别的特点,RFID技术越来越受到各大厂商的青睐,它在仓储物流、产品防伪、产品流通及产品维护追踪等领域有着极大的应用潜力。文章分析了RFID技术的基本原理,介绍了它在供应链管理、安全与身份识别及移动追踪等领域的应用。RFID技术也面临很多挑战,有待进一步研究。     

多天线的空时处理技术在CDMA系统中的应用

本介绍了无线通信中的多天线与空时处理技术，分析了多天线技术的原理和应用。章追踪了空间通信领域的一些最新动态，在最后介绍了空时编码技术。     

基于微表情追踪的课堂教学效果即时反馈系统设计

近几年来,课堂教学效果反馈评价手段与方式越来越多,其中不乏探究与应用人工智能领域的人脸识别与表情特征提取与分类技术,文章内容是通过列举分析了现如今课堂教学效果反馈方式及其优缺点,结合人工智能领域表情识别与分类技术应用于课堂教学效果反馈现状,提出一种基于微表情追踪的课堂教学效果即时反馈系统设计的概念模型,希望对以后的人工...     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.