虚拟现实航天仿真技术研究

现阶段的航天仿真一般集中在多媒体仿真与可视交互仿真,其沉浸感不强。针对以上不足,论文结合虚拟现实仿真技术的特点,利用多通道显示技术和一系列开源软件开发了一个基于虚拟现实技术的航天仿真系统,并且结合实际应用提出各通道独立显示和完全显示模式,实现了数据计算与三维演示部分的分离显示和数据驱动,弥补了现在多通道演示系统形式单一的不足。该系统具有平台移植性好,沉浸感强等特点。     

面向虚拟现实模拟平台的动作编辑系统设计

目的 解决体感设计中虚拟现实模拟平台动作设计面临的技术门槛高、动作难以灵活编辑等问题,优化动作设计流程,提高体感设计师的设计质量。方法 通过对现有虚拟现实模拟平台的动作编辑过程和需求进行分析,提出一种非参数化的VR模拟平台动作编辑系统,对动作编辑系统的功能构架、操作流程和软件界面进行设计,实现了VR模拟平台动作设计的非线性编辑和关键信息可视化等功能。结论 所构建的动作编辑系统可以提高设计的可操作性,并有效提升体感设计的质量,论证了新系统的有效性和可行性,探讨了新手和专家体感设计师在借助不同系统进行设计时,设计工效评价的差异,为VR体感设计研究提供了参考和技术支持。     

VR交互体验中沉浸感与舒适度的平衡设计

目的 虚拟现实技术让体验者获得亲临环境的感受,而高沉浸感带来的眩晕往往让用户体验的舒适度大为降低,沉浸感与舒适度是评价虚拟现实内容质量的两个重要指标.在实际开发过程中,VR交互体验中沉浸感和舒适度的矛盾也是一直以来限制虚拟现实技术广泛应用的一个主要因素.本文从沉浸感和舒适度的概念及相关影响因素入手,提出自然交互、稳定视觉和多通道刺激补偿综合设计的原则.方法 应用上述3种原则,进行虚拟场景作品设计,并与传统方法作品进行对比实验,采用5点沉浸感量表和SSQ量表分别评价两组作品的沉浸感和舒适感.结论 综合设计原则对平衡沉浸感和舒适度有一定效用,可以增强虚拟现实内容的沉浸感并有效降低虚拟现实运动症的发生率,是一种没有副作用且可有效平衡沉浸感和舒适度的技术方案.     

符号学在VR 手势交互设计中的应用研究

经过分析现实与虚拟现实（VR）之间的符号学联系,提出VR 中的手势中以现实为原形的符号化设计方法。并以Microsoft 的Kinect 系统手势为例论证了其在设计中的可行性,并最终应用于湖南大学设计艺术学院的手势交互设计实践中。     

影视VR技术在听觉音响设计中的应用与案例研究初探(下)

虚拟现实技术的研究和实现,近年来呈现井喷式爆发。主流公司推出了全新的VR显示、头部追踪、手部传感等一系列VR硬件产品,同时交互性是VR区别与传统媒介的突出特点,为未来的音视频发展带来了无限可能。本文在《影视VR技术在听觉音响设计中的应用与案例研究初探》(上)的研究基础之上,继续探讨VR音频的相关技术与实践要点,进而从声音设计的角度出发,分析虚拟现实技术在影视领域的不同交互方式,思考如何在虚拟现实环境下构造沉浸声场,为观众带来沉浸式观赏体验。     

体感展示系统中的交互映射动作分析与研究

目的对体感交互模式中映射动作进行分析以解决交互过程中出现的误操作问题,以获得一种避免确认模糊的解决方案,从而提高用户体感操作体验。方法分析体感交互中误操作产生的原因,以设计心理学、人机工程学相关知识为依据,通过体感传感器Kinect 2.0进行实验,比较分析解决方案。结果得到了一套解决体感交互中所涉及的触发模糊问题的解决方案,并在实际应用中验证方法的可行性。结论在现有Kinect传感器的硬件条件下,根据其识别精度确定标准触发手势,通过既定算法实现手势动作对系统指令的映射关系,并在苗侗木制民居个性化定制系统中得到检验与应用。     

体感交互中的基础点击任务工效评估

随着以微软Kinect为代表的体感设备的问世,人机交互跨入了体感交互的新时代,为用户在交互过程中带来了更大的自由度。作为一种新兴的交互设备,有必要对其进行全面而深入的人机工效评估研究。费茨法则(Fitts'law)是传统人机工效研究的理论基础,具有广泛的适用性和有效性。本文设计了一个简便易行的基于Kinect检测跟踪的光标驱动策略,并通过点击实验检验了费茨法则在体感交互场景中的有效性,同时还分析对比了体感交互在不同运动方向上的人机工效和稳定性的差异。结果表明即便在不同运动方向条件下,体感交互的人机工效也依然服从费茨法则。本文的评估研究对相应的用户界面设计具有很好的理论参考意义。     

全景体感交互电影的创作模式研究

本文以特定的虚拟现实电影形式为切入点,探讨以沉浸感、交互性和全景化为核心特征的全景体感交互电影的新型创作模式。通过分析观影环境的变化、叙事结构的演变、拍摄与剪辑的模式以及放映设备的特征,勾勒出全景体感交互电影的基本框架,从媒介比较的视角探讨了全景体感交互电影的创作规律。     

面向商业型公共空间的体感互动应用设计――以“奇妙万圣节”体感互动游戏为例

文章从体感互动设备的应用角度出发,深入分析商业型公共空间中体感互动的应用形式。在本次研究中,以"奇妙万圣节"为例,详细地从产品的目标、功能、交互、可视化效果的设计角度,分析了设计一款基于Kinect的体感互动游戏的研究方法和设计思路。     

交互方式对VR电影观众沉浸感影响的研究——从“手柄交互”到“裸手交互”

虚拟现实（VR）电影是将VR技术与电影艺术融合在一起的全新电影形式,其最直观的两个特征是“交互”和“沉浸”,其中沉浸感大多是通过“交互”来强化的。因此,本文通过研究VR电影中不同交互方式对沉浸感的影响,致力于找出更适合VR电影的交互方式,从而增强观影沉浸感。通过对当前主流的“手柄交互”“裸手交互”两种VR技术进行对比分析,发现“手柄交互”方式会使观众在观影中产生间离效果进而影响沉浸感,而“裸手交互”通过增强观众在观影时的“身体在场”幻觉,营造出最大程度的临场感,并将VR电影“热媒介”的属性进一步强化,增强了观众在观影时的沉浸体验,使观众体验真正意义上的沉浸式全感官电影。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.