Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Speci...Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Specifically, it examined whether VR-based OKS could reduce visual dependency more effectively than visual deprivation through eye closure. Methods: Ten healthy adults participated in this study. A balance function meter was used to measure postural stability, including Romberg ratios before and after two conditions: VR-based OKS (VR + OKS) and eye closure (EC). Participants performed a two-minute standing task under each condition in random order, with adequate rest between tasks. In the VR + OKS condition, a smartphone-based VR headset presented a rotational OKS, while in the EC condition, participants stood with their eyes closed. Statistical analyses were conducted using paired t-tests to compare pre- and post-task Romberg ratios. Results: No significant differences were observed in the pre-task Romberg ratios between conditions. After the VR + OKS condition, significant reductions in Romberg A and Romberg V were observed. In contrast, no significant changes were noted in Romberg ratios after the EC condition. Conclusion: VR-based OKS significantly reduced visual dependency, as indicated by decreased Romberg ratios, suggesting its potential to facilitate sensory reweighting during postural control. These findings highlight the utility of low-cost VR devices in balance rehabilitation for conditions involving high visual dependency. Future studies should expand on this preliminary research by including larger sample sizes and diverse populations to confirm its clinical applicability.展开更多
This article proposes a novel fuzzy virtual force （FVF） method for unmanned aerial vehicle （UAV） path planning in compli-cated environment. An integrated mathematical model of UAV path planning based on virtual fo...This article proposes a novel fuzzy virtual force （FVF） method for unmanned aerial vehicle （UAV） path planning in compli-cated environment. An integrated mathematical model of UAV path planning based on virtual force （VF） is constructed and the corresponding optimal solving method under the given indicators is presented. Specifically,a fixed step method is developed to reduce computational cost and the reachable condition of path planning is proved. The Bayesian belief network and fuzzy logic reasoning theories are applied to setting the path planning parameters adaptively,which can reflect the battlefield situation dy-namically and precisely. A new way of combining threats is proposed to solve the local minima problem completely. Simulation results prove the feasibility and usefulness of using FVF for UAV path planning. Performance comparisons between the FVF method and the A＊ search algorithm demonstrate that the proposed approach is fast enough to meet the real-time requirements of the online path planning problems.展开更多
This article investigates virtual reality (VR)-based teleoperation with robustness against modeling errors. VR technology is an effective way to overcome the large time delay during space robot teleoperation. However,...This article investigates virtual reality (VR)-based teleoperation with robustness against modeling errors. VR technology is an effective way to overcome the large time delay during space robot teleoperation. However, it depends highly on the accuracy of model. Model errors between the virtual and real environment exist inevitably. The existing way to deal with the problem is by means of either model matching or robot compliance control. As distinct from the existing methods, this article tries to combine m...展开更多
Virtual tourism is the application of virtual reality technology in tourism industry,in which the key is to construct lifelike virtual environment.This paper introduces several main methods in producing virtual enviro...Virtual tourism is the application of virtual reality technology in tourism industry,in which the key is to construct lifelike virtual environment.This paper introduces several main methods in producing virtual environment,such as landform formation with the help of height field method,construction of complicated three-dimensional models in virtual environment through 3DS MAX,construction of lifelike tree models using Billboard technique and Cross Billboard technique,and adoption of texture mapping,LOD(level of detail),and collision testing technique to increase sense of reality in virtual environment.Finally a lifelike virtual tourism environment is realized under the context of Visual C++6.0 through OpenGL.展开更多
目的:采用网状Meta分析系统评价不同非侵入性神经调控技术对孤独症谱系障碍儿童的康复疗效。方法:系统检索中国知网、维普网、万方数据知识服务平台、中国生物医学文献数据库、Pub Med、Web of Science、Cochrane Library、Embase数据库...目的:采用网状Meta分析系统评价不同非侵入性神经调控技术对孤独症谱系障碍儿童的康复疗效。方法:系统检索中国知网、维普网、万方数据知识服务平台、中国生物医学文献数据库、Pub Med、Web of Science、Cochrane Library、Embase数据库,选择不同非侵入性神经调控技术改善孤独症谱系障碍的随机对照试验,检索时限为各数据库建库至2025年1月,由2名研究者独立进行文献筛选、数据提取并对纳入的研究进行质量评价,应用Stata 18.0软件对数据进行网状Meta分析。结果:共纳入32个随机对照试验,涉及8种干预方式。网状Meta分析结果显示,在常规康复训练的基础上,在改善孤独症行为量表评分方面,虚拟现实技术效果最佳[SMD=-12.55,95%CI(-20.85,-4.25),P<0.05],其次为θ爆发式磁刺激[SMD=-11.34,95%CI(-20.94,-1.74),P<0.05]、重复经颅磁刺激[SMD=-9.28,95%CI(-12.80,-5.77),P<0.05]、神经反馈技术[SMD=-8.75,95%CI(-15.26,-2.23),P<0.05];在儿童孤独症评定量表评分方面,虚拟现实技术改善效果最为显著[SMD=-6.36,95%CI(-9.61,-3.11),P<0.05],其次为重复经颅磁刺激[SMD=-5.98,95%CI(-9.46,-2.51),P<0.05]、神经反馈技术[SMD=-4.63,95%CI(-9.14,-0.13),P<0.05]、经皮神经电刺激[SMD=-4.14,95%CI(-5.73,-2.55),P<0.05];在孤独症治疗评估量表评分方面,神经反馈技术改善效果最显著[SMD=-16.44,95%CI(-24.10,-8.78),P<0.05],其次为虚拟现实技术[SMD=-14.09,95%CI(-22.45,-5.73),P<0.05]、重复经颅磁刺激[SMD=-12.06,95%CI(-16.45,-7.68),P<0.05]、经皮神经电刺激[SMD=-10.58,95%CI(-20.44,-0.72),P<0.05]、经颅直流电刺激[SMD=-9.75,95%CI(-18.62,-0.88),P<0.05]。结论:当前证据表明,在常规康复训练基础上,不同非侵入性神经调控技术对孤独症谱系障碍的改善效果存在差异。虚拟现实技术在改善孤独症行为量表和儿童孤独症评定量表评分方面表现出最佳效果,而神经反馈技术在孤独症治疗评估量表评分方面的改善效果最为显著。受纳入研究数量和质量的限制,上述结论尚待更多高质量研究予以验证。展开更多
文摘Purpose: This study aimed to investigate the immediate effects of optokinetic stimulation (OKS) using virtual reality (VR) on visual dependency and sensory reweighting in postural control during static standing. Specifically, it examined whether VR-based OKS could reduce visual dependency more effectively than visual deprivation through eye closure. Methods: Ten healthy adults participated in this study. A balance function meter was used to measure postural stability, including Romberg ratios before and after two conditions: VR-based OKS (VR + OKS) and eye closure (EC). Participants performed a two-minute standing task under each condition in random order, with adequate rest between tasks. In the VR + OKS condition, a smartphone-based VR headset presented a rotational OKS, while in the EC condition, participants stood with their eyes closed. Statistical analyses were conducted using paired t-tests to compare pre- and post-task Romberg ratios. Results: No significant differences were observed in the pre-task Romberg ratios between conditions. After the VR + OKS condition, significant reductions in Romberg A and Romberg V were observed. In contrast, no significant changes were noted in Romberg ratios after the EC condition. Conclusion: VR-based OKS significantly reduced visual dependency, as indicated by decreased Romberg ratios, suggesting its potential to facilitate sensory reweighting during postural control. These findings highlight the utility of low-cost VR devices in balance rehabilitation for conditions involving high visual dependency. Future studies should expand on this preliminary research by including larger sample sizes and diverse populations to confirm its clinical applicability.
基金National Natural Science Foundation of China (60975073)Aeronautical Science Foundation of China (2008ZC13011)+1 种基金Research Foundation for Doctoral Program of Higher Education of China (20091102110006)Fundamental Research Funds for the Central Universities
文摘This article proposes a novel fuzzy virtual force （FVF） method for unmanned aerial vehicle （UAV） path planning in compli-cated environment. An integrated mathematical model of UAV path planning based on virtual force （VF） is constructed and the corresponding optimal solving method under the given indicators is presented. Specifically,a fixed step method is developed to reduce computational cost and the reachable condition of path planning is proved. The Bayesian belief network and fuzzy logic reasoning theories are applied to setting the path planning parameters adaptively,which can reflect the battlefield situation dy-namically and precisely. A new way of combining threats is proposed to solve the local minima problem completely. Simulation results prove the feasibility and usefulness of using FVF for UAV path planning. Performance comparisons between the FVF method and the A＊ search algorithm demonstrate that the proposed approach is fast enough to meet the real-time requirements of the online path planning problems.
基金National Natural Science Foundation of China (60675054)National High-Tech Research and Development Program (2006AA04Z228)"111" Project (B07018)
文摘This article investigates virtual reality (VR)-based teleoperation with robustness against modeling errors. VR technology is an effective way to overcome the large time delay during space robot teleoperation. However, it depends highly on the accuracy of model. Model errors between the virtual and real environment exist inevitably. The existing way to deal with the problem is by means of either model matching or robot compliance control. As distinct from the existing methods, this article tries to combine m...
基金Supported by National Natural Science Foundation(40801124)Intellectual Innovation Project of Chinese Academy of Science(kzcx2-yw-224)~~
文摘Virtual tourism is the application of virtual reality technology in tourism industry,in which the key is to construct lifelike virtual environment.This paper introduces several main methods in producing virtual environment,such as landform formation with the help of height field method,construction of complicated three-dimensional models in virtual environment through 3DS MAX,construction of lifelike tree models using Billboard technique and Cross Billboard technique,and adoption of texture mapping,LOD(level of detail),and collision testing technique to increase sense of reality in virtual environment.Finally a lifelike virtual tourism environment is realized under the context of Visual C++6.0 through OpenGL.
