沉浸式虚拟训练中的虚拟手操控技术研究

将人手的自然动作加入沉浸式虚拟现实系统中,可有效提高系统的沉浸感和交互性,简便快捷、成本低廉的虚拟手建模及操控技术,有助于此项内容的推广应用;在对虚拟手骨骼结构模型分析的基础上,提出了基于Leap Motion的虚拟手控制方法和流程;以维修训练为任务背景,设计了四种用于虚拟手操作的手势规则,并对实现流程和关键技术进行了分析;构建基于Unity3D引擎的原型系统对虚拟手进行仿真验证,结果表明,基于Leap Motion的虚拟手操控简单、交互自然,可以满足虚拟现实系统交互需要。     

基于Leap Motion的虚拟课堂手势交互方法

随着虚拟现实技术的飞速发展, Leap Motion等体感传感器出现并被广泛地应用在人机交互中.针对Leap Motion体感控制器在识别范围边缘识别率低且识别速度慢的问题提出了一种基于深度神经网络的Leap Motion手势交互方法.该方法在定义的交互手势基础上,设计了三维交互系统并应用到虚拟场景中.系统首先通过Leap Motion进行数据捕捉,对获取到的红外图像采用深度神经网络进行特征提取并实现对手势的分类识别,然后结合Leap Motion获取的手部坐标前后帧的变化来判断动态手势,最终结合动态手势完成虚拟场景中的交互功能.经过实验验证,本文手势识别方法无论是在识别速度还是识别精度上都优于Leap Motion自带的手势识别方法,同时在Leap Motion识别范围边界处仍能保持较高的识别率.     

基于Leap Motion的手势控制技术初探

最新体感设备Leap Motion的面世提供给用户一种全新的体验, 即通过跟踪探测动态手势可以进行体感游戏、虚拟演奏、凌空绘画等的非接触式人机交互. 文章首先对Leap Motion的技术特点进行介绍, 并对同类型设备进行对比总结, 介绍了Leap Motion的相关应用和发展前景. 文章分析了Leap Motion的原理和技术基础, 然后提出基于Leap Motion的手势控制技术, 最后以一个基于Unity 3D的手势控制虚拟场景中的物品运动的具体实例, 对Leap Motion手势控制技术的实现进行了细节介绍.     

VR环境下基于Leap Motion的三维模型空间位姿自适应调整方法

针对目前基于Leap Motion的人机交互研究中存在的虚拟手与三维模型相互干涉、三维模型与虚拟手空间位姿同步率低的问题,提出一种基于Leap Motion的三维模型空间位姿自适应调整方法.通过将物理交互方法与启发式交互方法相结合,实现基于虚拟手位姿信息的三维模型空间位姿自适应实时精确调整,使人机交互仿真过程更加逼真,提升用户的交互式体验感.借助HTC VIVE所搭建的沉浸式虚拟现实环境,验证了该方法的可行性.     

基于Leap Motion和Unity3D的虚拟沙画手势识别及交互

虚拟仿真技术的快速发展及体感设备的不断更新为沙画动画这一全新的艺术创作形式带来新的灵感。针对沙画现场作画工序复杂的问题,结合Leap Motion设备和Unity3D开发环境完成手势识别并驱动虚拟手实现虚拟沙画效果。首先,依据Leap Motion捕捉到的手势坐标及方向信息提取手部关键点;然后提出角域划分的方法并引入新的特征向量,将其与提取信息串联作为手势分类依据;最后,根据自行定义的沙画手势语义驱动虚拟手完成虚拟沙画创作。实验证明,利用Leap Motion完成近距离手势识别效果较其他方法结果更加精准,实时性较高,手势跟踪稳定,虚拟沙画绘画过程沉浸感强。     

基于Leap Motion的手术室无干扰交互技术

在手术室中,传统人机交互技术很大程度上依赖于鼠标、键盘、触摸屏等输入设备,但这种接触式交互有导致患者感染的风险.而虚拟操作人机交互过程采用计算机视觉来获取手势信息,在交互的自然性与成本上有很大的优势,是现如今人机交互领域发展的主要趋势.本文介绍了一种基于Leap Motion的手势控制技术,利用AR技术和Leap Motion设备,使得手术过程中医生无需接触手术设备,在非接触式设备的帮助下使医生能彻底远离因接触设备给手术带来的干扰和手术风险.实验表明,相比于传统的接触式交互技术,基于Leap Motion的手术室无干扰交互技术在一定程度上减少了接触式交互所带来的手术感染风险并增加了医生操作的易用性.     

基于Leap Motion的手势识别在虚拟交互中的研究*

针对虚拟场景中的自然手势交互进行了研究,提出了基于Leap Motion的动态指尖手势轨迹识别方法。首先借助Leap Motion设备采集指尖在场景中运动时产生的坐标并同时对数据进行预处理,然后从这一系列坐标中找出起始和结束位置并提取出有效的手势轨迹,再进行轨迹优化和手势初步分类,基于加权欧氏距离将轨迹和手势模板进行相似度计算,得到识别结果。采集200组手势数据进行实验,结果证明提出的方法具有很高的识别率,将方法应用在手势交互系统中,实现使用自然手势和虚拟物品进行交互,增加了交互乐趣,改善了交互体验。     

Leap Motion手势交互层次化校正方法研究

Leap Motion手势识别在识别区域边缘和手指遮挡部位存在识别不稳定的现象。提出了一种Leap Motion手势交互层次校正方法。该方法通过实时对比阈值方式分析Leap Motion的识别错误,并采用层次化的校正算法校正人手位置,解决人手交互过程中的识别不稳定现象。通过对实验进行分析,75%参与者对实验交互方式满意,80%参与者认为该方法更精确,且交互内容识别精度超过89%,充分证明了该方法能够提高Leap Motion的识别准确率,提升用户体验。     

基于Leap Motion的手语识别算法优化

Leap Motion设备产生的数据在虚拟环境中可以进行手势识别。通过识别和跟踪用户的手来生成虚拟3D手部模型,从而获取手势信息。本文设计了一种基于隐马尔可夫模型(Hidden Markov Model, HMM)分类算法来学习从Leap Motion中所获取的手势信息的系统,根据手势特征的重要性赋予不同权值,可进一步提高分类准确率,实现手语信息的识别输入。测试结果表明,识别准确率为86.1%,手语打字输入识别速度为每分钟13.09个字符,可显著提高聋哑人与正常人之间沟通的便捷性。     

基于Leap Motion的三维手势交互系统研究

手势识别的快速发展及体感设备的不断更新为三维手势交互提供了灵感,基于Leap Motion 手势识别和最邻近算法,建立了一种三维手势交互系统。首先对手势设计理论和交互手 势设计原则进行研究,基于此设计手势功能和建立手势库,并将手势库分为 8 种手势;其次进 行手势特征提取,建立手指关键点模型,获取手势特征的角度特征;然后计算 KNN 算法和 SVM 算法的手势识别效率,KNN 改进算法取得较好的识别效率;最后,设计三维交互系统,手势分 类为 4 个模块,每个模块有 2 个手势任务;20 名测试者中提取 1 600 组手势数据,并进行总采 集样本关节点均值的数据分析;设计三维交互系统模块,在 Unity3D 中创建的三维交互系统中 导入 1 600 组手势数据,根据自定义的 8 种手势驱动虚拟手完成交互设计过程,完成用户体验 分析和手势识别效率统计。通过研究发现,基于 Leap Motion 手势识别具有较高的识别效率, 三维手势交互系统富有创新性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.