Limits of visual perception in the technology of visual display terminals

. The limits of visual perception in present VDT technology for man-machine communication are considered. Essentially, these limits concern the reading of the displayed information and follow from the prevailing display conditions as to (i) luminous contrast, (ii) character shape, (iii) text layout and (iv) text colour. The effect of these conditions on legibility is quantitatively described from research results, and practical suggestions are given for improving display legibility, through changes in contrast polarity, character shape, layout and the way colour is used. Finally, a plea is made for including experts in visual ergonomics in the teams developing new display devices in the future.     

视景仿真实时显示技术的研究

视景模型实时显示与交互技术是目前分布式视景仿真研究的关键技术。以视景实时显示为目的,探讨了雾化技术、实例化技术、纹理映射技术、纹理裁减、场景模型分块、LOD（level of detail）等技术,重点研究了面向大场景仿真的实时显示问题,通过对各种视景仿真实时显示技术和场景显示调度算法的综合应用,实现了对三维大场景海量数据进行较为流畅的显示,满足了大场景实时显示帧率要求,并具有较好的显示精度和清晰度。     

基于瞳孔定位技术的视觉跟踪系统的研究

设计了一款基于瞳孔定位技术的视觉跟踪系统。该系统通过安装在眼镜上的摄像头采集人眼球瞳孔运动图像,并利用硬件电路分离视频同步信号,然后将信息传送至S3C6410嵌入式处理器,处理器利用图像处理算法计算出人的瞳孔运动轨迹,从而得到人眼瞳孔的实时定位信息。该系统具有较为广泛的应用前景,可以通过人眼睛的转动来实现对各种智能化设备的控制,能够应用于残疾人智能护理、病床智能护理等实际领域。     

加密技术演变与发展

在网络急剧发达化的今天,网络安全问题已经成为了一个很重要的问题,网络的安全性直接影响着网络用户的隐私、金钱等利益关系。针对网络安全问题,加密技术应运而生,对网络中的不安全因素进行科学的加密过程,这才能使我们在网络环境中有着安全保障,避免黑客的不正当妨碍与侵犯。本文对信息加密的历史演变、信息加密的方式、以及未来加密技术的发展方向做了详细的研究,充分展现了加密技术的发展趋势。     

Unsupervised visual domain adaptation via discriminative dictionary evolution

Pattern Analysis and Applications - This work focuses on unsupervised visual domain adaptation which is still challenging in visual recognition. Most of the attention has been dedicated to seeking...     

The evolution of load/unload technology

 Load/unload (L/UL) has recently replaced contact start-stop (CSS) technology in major segments of the hard disk-drive (HDD) industry. Although L/UL has existed since the earliest HDDs, recent implementations use fixed ramp L/UL systems, which are considerably simpler than earlier versions. L/UL offers multiple advantages over CSS, including practically unlimited start-stop cycles and improved shock robustness. However, disk damage can occur in L/UL drives due to head-disk contacts, and a variety of parameters including vertical L/UL speed and slider corner radius should be optimized to minimize damage. Tight control of key tolerances is essential to maximize available disk real estate and minimize the required disk spacing to accommodate L/UL. Power-off retract systems for L/UL must produce higher retract torque than those for CSS designs, leading to new retract circuit designs. Received: 6 July 2001/Accepted: 21 September 2001     

A differential evolution based algorithm for breaking the visual steganalytic system

Image steganography is the process of sending messages secretly by hiding the message in image content. Steganalytic techniques are used to detect whether an image contains a hidden message by analyzing various image features between stego-images (the images containing hidden messages) and cover-images (the images containing no hidden messages). In the past, genetic algorithm (GA) was applied to design a robust steganographic system that breaks the steganalytic systems. However, GA consumes too much time to converge to the optimal solution. In this paper, we use a different evolutionary approach, named differential evolution (DE), to increase the performance of the steganographic system. The key element that DE is distinguished from other population based approaches is differential mutation, which aims to find the global optimum of a multidimensional, multimodal function. Experimental results show that the application of the DE based steganography not only improves the peak signal to noise ratio (PSNR) of the stego-image, but also promotes the normalized correlation (NC) of the extracted secret message for the same number of iterations. It is observed that the percentage increase in PSNR values ranges from 5% to 13% and that of NC values ranges from 0.8% to 3%.     

Influence of high ambient temperature and humidity on visual sensitivity

Abstract

The visibility of sinusoidally modulated gratings was measured psychophysically during 3 hours of exposure to either (i) a control, (ii) a warm-humid or (iii) a hot-dry atmosphere. No significant loss of contrast sensitivity in the heat conditions could be demonstrated for low spatial frequencies (≤ 3·0 c/deg) but an increasing loss with increasing frequencies (maximal above 10 c/deg). The heat-induced performance change appeared within 30min of exposure.     

多通道技术在视景仿真系统中的应用

视觉通道是虚拟环境系统中最重要的人机交换界面,利用三通道投影可以得到更广阔的视角效果,增强“沉浸感”.详细分析了Vega模块Dvega的实现原理,给出了视锥偏移计算公式,同时给出了利用Vega编程实现三通道视景的具体方法.     

可视化XML文件的自动生成技术研究应用

界面自动生成工具是电信OMC（操作维护中心）中CAF（公共应用功能）模块3大核心技术之一。为了可视化地编辑XML文件，在开发该工具的过程中对组件拖动技术进行了详细研究。将Java、JDOM和XML技术相结合，实现了对工具中组件的拖动和现有界面的保存。     

Impact on retail checkout ergonomics of scanner technology evolution and package design

The design of bar code scanners has steadily improved scanning performances over the past 20 years. Changes in scan patterns, improvements in decode algorithms, and design features of the hardware user interface have resulted in scanners that are ergonomically superior both in biomechanics and overall performance. This study reviewed scanner performance and technological developments, and compare these to changes in checkstand use and the mix of merchandise packages scanned. The results indicate that the impact of future innovations in scanner design to improve throughput and the accuracy of data captured will be minimal. The greatest challenge to improve overall checkout performance is for merchandise suppliers to consider the ergonomics of scanning merchandise based on package design and placement of the bar code.

Relevance to industry

This work shows the impact of scanner design on cashier productivity in the retail checkout environment. Improvements in the user interface of scanners and the scanner optical recognition logic has shown a dramatic impact on the total percentage of scanned items. Package design and bar code placement is the next area to enhance the ergonomics of scanning.     

Mobile video literacy: negotiating the use of a new visual technology

In this article, we examine the practice of learning to produce video using a new visual technology. Drawing upon a design intervention at a science centre, where a group of teenagers tried a new prototype technology for live mobile video editing, we show how the participants struggle with both the content and the form of producing videos, i.e., what to display and how to do it in a comprehensible manner. We investigate the ways in which video literacy practices are negotiated as ongoing accomplishments and explore the communicative and material resources relied upon by participants as they create videos. Our results show that the technology is instrumental in this achievement and that as participants begin to master the prototype, they start to focus more on the narrative aspects of communicating the storyline of a science centre exhibit. The participants are explicitly concerned with such issues as how to create a comprehensible storyline for an assumed audience, what camera angles to use, how to cut and other aspects of the production of a video. We consider these observed activities to be candidate steps in an emerging mobile video literacy trajectory that involves developing a capacity to document and argue by means of this specific medium.     

视觉优化的移动三维图形自适应重构技术研究

为保证移动终端上生成满意的可视化结果,适应不同软硬件环境的要求,提出了一种基于视觉重要性的模型分层选择自适应绘制方法.该方法根据场景中对象的视觉重要性,自动调节不同级别细节层次模型的分布比例,满足限时计算机制的要求,使场景的生成时间保持较好的稳定性.在动态场景中对该方法进行的实验结果表明,该方法能在保证场景可视化真实感的基础上,有效提升场景的绘制速度,为移动终端图形绘制成本和视觉效果提供了一种折中解决方案.     

基于WEB的远程可视化并行计算化学系统

以PC Linux并行计算系统为支撑,研制了基于Web方式的可视远程计算化学系统RVCCS。此系统使用Web技术替代传统Telnet方式的远程计算模式,在Web界面中实现了作业提交、作业后台运行、作业状态实时查看、计算结果图示化、分子结构三维化等功能,提供了一种简单易用的远程可视计算方式。使用此系统建立的Web方式远程计算化学站点GHPCC(http：／／www．ghpcc．gzu．edu．cn)自1998年为国内用户提供计算服务以来,接受了各高校和科研单位化学工作者提交的上万次远程计算,为化学工作者提供了一个分子模拟和化学计算的有力工具。     

视觉引导技术在SCARA机器人装配任务中的应用

基于实际生产项目,提出了一种针对平面关节型机器人(SCARA)平面装配任务的手眼标定方法。对线性标定法的输出通过多次迭代使得累积误差和逐渐减小,相较于使用线性标定法来进行手眼标定,视觉定位的平均定位误差降低了0. 4 mm,最大定位误差降低了0. 6 mm。在使用SCARA机器人进行毫米(mm)级作业时,使用迭代线性标定法比传统的线性标定法有更高的视觉定位精度。同时,末端执行器完成对目标工件的抓取任务之后,使用解线性方程的思想求解SCARA机器人完成装配任务的末端位姿,通过实际工程项目的验证,装配成功率可达98. 6%。     

基于形象化标签推荐技术的聋儿康复资源系统

针对目前教育、教学资源系统中存在的问题,在以用户为中心的场景设计方法指导下,提出了简单、易学、易用和高效4个层次递进的系统设计开发目标,并重点分析研究了Web2.0的个性化服务:标签和推荐服务.结合这两种服务的优势,在提出和实现形象化标签推荐技术后,阐述了其设计与实现.结合聋儿康复资源系统的设计与开发,详细地介绍了整个系统的功能框架、实现流程以及形象化标签在系统中的运用.最后对全文进行了总结,并对下一步研究工作做出了展望.