"Conflicting" motion cues to the visual and vestibular self-motion systems around 0.06 Hz evoke simulator sickness

The basic question this research addressed was, how does simulator sickness vary with simulated motion frequency? Participants were 11 women and 19 men, 20 to 63 years of age. A visual self-motion frequency response curve was determined using a Chattecx posture platform with a VR4 head-mounted display (HMD) or a back-projected dome. That curve and one for vestibular self-motion specify a frequency range in which vestibular and visual motion stimuli could produce conflicting self-motion cues. Using a rotating chair and the HMD, a third experiment supported (p < .01) the hypothesis that conflicting cues at the frequency of maximum "crossover" between the curves (about 0.06 Hz) would be more likely to evoke simulator sickness than would conflicting cues at a higher frequency. Actual or potential applications of this work include a preliminary design guidance curve that indicates the frequency range of simulated motion that is likely to evoke simulator or virtual reality sickness; for simulators intended to operate in this frequency range, appropriate simulator sickness interventions should be considered during the design process.     

XYLAN交换到北京

致力于网络交换技术和产品开发的XYLAN公司“全线交换技术、全面解决方案”技术巡展,于6月17日回到北京,为此次九城市的巡展划上圆满的句号。历时一月有余的巡展在XYLAN和用户之间架设了沟通的桥梁,XYLAN从用户那里了解了他们的需求,用户从XYLAN了解到了技术、方案,双方实现了真正的交换。 XYLAN在第三层交换技术和ATM技术方面拥有领先技术,他们设计生产的用于高速交换的ASIC芯片集成了500万个晶体管器件。由于设计灵活。ASIC芯片可在交换机中做到对100Mbps快速以太网交换     

目录服务转网络服务

3月9日,Novell 2000年电子商务及NetWare 5.1发布巡展在我国开始,并发布了 NetWare 5.1以及ZENworks for Servers 和 ZENworks for Networks 等基于 eDirectory 的网络服务软件,同时 Novell 公司还携手 IBM 公司与 Lucent 公司提供了电子商务解决方案。Novell 公司表示,今后将在 Internet 市场中扮演网络服务软件供应商的角色。     

Effects of characteristics of image quality in an immersive environment

Image quality issues such as field of view (FOV) and resolution are important for evaluating "presence" and simulator sickness (SS) in virtual environments (VEs). This research examined effects on postural stability of varying FOV, image resolution, and scene content in an immersive visual display. Two different scenes (a photograph of a fountain and a simple radial pattern) at two different resolutions were tested using six FOVs (30, 60, 90, 120, 150, and 180 deg.). Both postural stability, recorded by force plates, and subjective difficulty ratings varied as a function of FOV, scene content, and image resolution. Subjects exhibited more balance disturbance and reported more difficulty in maintaining posture in the wide-FOV, high-resolution, and natural scene conditions.     

重在协作

SAP公司将在今后2年内向协同商务解决方案中心(CBSC)投资1000万美元,并透过与清华大学、上海交通大学、同济大学、西南财经大学和浙江大学的技术转移与合作,共同开发适合中国应用的协同商务解决方案。为什么会选择与国内的大学合作?CBSC的重点在哪?SAP公司亚太区总裁兼CEO LesHayman先生、大中国区总裁兼     

Airborne Doppler lidar techniques for observing severe thunderstorms

On 30 June 1981 the wind fields around an Oklahoma severe thunderstorm were observed in detail using an airborne Doppler lidar operated by NASA. Despite uncertainties caused by inertial navigation errors and problems in sampling some of the aircraft attitude and motion parameters, reasonably clear pictures of the distributions of relative reflectivity, horizontal wind velocity, and velocity spectral width near the cloud base have been obtained. Aspects of the design and functioning of the NASA lidar relevant to the collection and analysis of the data are described.     

网络CAD技术在工程设计中的应用

本文介绍计算机辅助设计(CAD)通过各种网络技术手段在工程设计的各个阶段的运用。包括各工种间,工种内部的协同工作;设计进度和质量的实时动态管理;大量设计资料的储存与检索。     

10MW高温气冷实验堆项目管理系统的框架设计

介绍了１００ＭＷ高温气冷实验堆工程项目管理系统的初步设计框架，在此基础上，重点介绍了核工程管理信息系统（ＭＩＳ）和工程监控系统（ＰＭＳ）的功能设计以及ＭＩＳ各子系统的功能设计。本文在ＭＩＳ和决策支持系统（ＤＳＳ）的开发方法上也作一些尝试。     

一种基于MRHT的航迹起始新方法研究

针对随机Hough变换法（RHT）只适应于稀疏杂波环境且最大采样次数Kmax难于选取等问题,本文提出一种改进的随机Hough变换法（MRHT）,对RHT算法加入了采样终止准则和约束条件限制。仿真实验表明,该算法与RHT相比,不仅有效的减少了虚警航迹概率,而且在计算时间方面大大减小,适于工程应用。     

山东省旅游电子商务存在的问题及对策分析

山东作为一个旅游大省,电子商务的迅速发展为山东旅游业提供了新的机遇和挑战。发展旅游电子商务不仅是山东省旅游业自身发展的需要,也是信息时代山东省旅游业面对国内外旅游业竞争的必需。文章分析了山东省旅游电子商务发展的优势、现状、问题,并在此基础上提出了发展旅游电子商务的对策,为山东省旅游电子商务今后的发展提供了一定的参考。