多元视觉显示中的变化盲问题

多元视觉显示界面逐渐成为主要的信息显示方式。观察者经常不能探测到场景中大的变化,并且高估自己的变化探测的能力,严重削弱了信息系统的使用效率。针对这种变化盲现象进行了回顾,分析总结影响操作人员变化探测能力的因素,对信息系统的显示界面设计使用和研究具有积极的指导意义。     

一种新型最短路径搜索算法的研究

在深入分析Dijksdtra算法的基础上,考虑到图节点之间的拓扑关系以及Dijksdtra算法在计算节点权值时,与已着色节点不相关节点权值存在∞（即该节点不可见）,文章提出了盲目区域最短路径搜索算法,由分析可知计算量大为减少,算法更优。     

基于机械倾斜方式的过顶跟踪算法

首先推导了卫星过顶时盲区的计算公式,然后给出了实施机械倾斜过顶跟踪时,基于TILT A'-E'型三轴座架的倾斜范围的选取方法和倾斜轴方向的确定途径。经实际工程验证,这种倾斜范围的选取方法和倾斜轴方向的确定途径是合理、可行的。     

基于盲目搜索的半自动栅格矢量转换方法的研究

从与传统方法不同的角度着手,以盲目搜索为指导思想,研究了一种新的半自动的将栅格数据转换为矢量数据的方法。与传统转换方法相比,该方法不需对栅格数据进行预处理,可以方便地处理最多到32位真彩色图像,特别适合交叉点多,拓扑复杂的大图像的处理。该方法转换效率高、速度快,并在试验和实践中取得了很好的效果。     

Research on Internet use by Spanish-speaking users with blindness and partial sight

The results of an online questionnaire for Spanish-speaking Internet users with visual impairment are presented in this work. The research was carried out during 2002. The data collected shows that Internet is a very valuable tool for visually impaired people, as it allows them to access written information in an autonomous and instantaneous manner and to communicate with others through individual email and discussion lists. However, all users found frequent and important problems of accessibility in many web pages that prevent them from having complete access to the information and functionalities of those websites.

Development of a Wearable Computer Orientation System

People with severe visual impairment need a means of remaining oriented to their environment as they move through it. A series of indoor and outdoor trials using a variety of technologies and interfaces led to the development and evaluation of three promising wearable orientation interfaces: a virtual sonic beacon, speech output, and a shoulder-tapping system. Street crossing was used as a critical test situation in which to evaluate these interfaces. The shoulder-tapping system was found most universally usable. Results indicated that, given the great variety of co-morbidities within this population, which is comprised of mostly older persons, optimal performance and flexibility may best be obtained in a design that combines the best elements of both the speech and shoulder-tapping interfaces.     

Identification of ground materials with the aid of tapping sounds and vibrations of long canes for the blind

One of the functions of the long cane for the blind is to inform the user about the ground he or she is walking on. Three experiments were conducted to study to what extent sounds and vibrations from long canes make it possible to identify ground materials. The first experiment investigated how observers could identify four materials by sounds made, when tapping the long cane. The correlations of these behavioural data with the spectral contents of the tappings showed that the materials were characterized by different frequency bands. The most important frequency range resided between 500 and 2500 Hz with a preponderance in the higher frequencies. In the second experiment learning effects were studied and resulted in the same conclusions. The third experiment was designed to study how canes differ in their capacity to make available to the hand useful vibratory information on the hardness, or impedance, of the material, but no statistically significant differences were found between them. The ranking order of the canes from the first two experiments suggested that the overall elasticity should be an important factor, when constructing an acoustically adequate cane.     

The effects of precueing on vibrotactile reaction times: implications for a guidance device for blind people

Abstract

Reaction times to a vibrotactile display are examined in two experiments which address the issues of secondary task and stimulus preview. Results suggest that although performing a secondary task significantly increases reaction times to a vibrotactile stimulus delivered to the fingers, this can be compensated for by presenting precueing stimuli. The implications of these findings in relation to guidance devices for the blind are discussed.     

Elimination of scan blindness in microstrip scanning array antennas using defected ground structure

In this paper, applying DGS to a linear six-element microstrip scanning array antenna, the blindness angle is removed. The method of moments is utilized in analyzing the proposed structure. The technique uses the band-stop characteristics of microstrip line filters to block the surface waves and reduce the coupling between elements that causes the blindness angle.