首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Notwithstanding the recent diffusion of the stereoscopic 3D technologies for the development of powerful human computer interaction systems based on augmented reality environment, with the conventional approaches an observer freely moving in front of a 3D display could experience a misperception of the depth and of the shape of virtual objects. Such distortions can cause eye fatigue and stress for entertainment applications, and they can have serious consequences in scientific and medical fields, where a veridical perception of the scene layout is required. We propose a novel technique to obtain augmented reality systems capable to correctly render 3D virtual objects to an observer that changes his/her position in the real world and acts in the virtual scenario. By tracking the positions of the observer’s eyes, the proposed technique generates the correct virtual view points through asymmetric frustums, thus obtaining the correct left and right projections on the screen. The natural perception of the scene layout is assessed through three experimental sessions with several observers.  相似文献   

2.
Occlusion in collaborative augmented environments   总被引:1,自引:0,他引:1  
Augmented environments superimpose computer enhancements on the real world. Such augmented environments are well suited for collaboration of multiple users. To improve the quality and consistency of the augmentation the occlusion of real objects by computer-generated objects and vice versa has to be implemented. We present methods how this can be done for a tracked user's body and other real objects and how irritating artifacts due to misalignments can be reduced. Our method is based on simulating the occlusion of virtual objects by a representation of the user modeled as kinematic chains of articulated solids. Smoothing the border between virtual world and occluding real reduces registration and modeling errors of this model. Finally, an implementation in our augmented environment and the resulting improvements are presented.  相似文献   

3.
Locales: supporting large multiuser virtual environments   总被引:1,自引:0,他引:1  
Creators of multiuser virtual environments naturally desire to make them large in spatial extent, large in numbers of objects, and large in numbers of users interacting with the environment. However, doing so creates several problems: efficiently managing the flow of large amounts of data between large numbers of users, representing precise position and velocity information about objects arrayed across a large volume of space, and allowing designers to create parts of a virtual environment separately and combine them together later. The concept of locales is based on the idea that even in a very large virtual world, most of what a single user can observe at a given moment is nevertheless local in nature. You would expect a large virtual world to be large primarily because, like a city, it combines a large number of relatively small, localized activities not because it contains very large individual activities. Locales divide a virtual world into chunks that can be processed separately. This division is purely an implementation issue-it is not apparent to the user. A user sees several locales at once-generally the locale containing the user's point of view and those neighboring it. The user does not see any seams between the locales nor any abrupt changes as the point of view moves from one locale to another, thereby changing the neighborhood set  相似文献   

4.
在面向服务体系结构和Web服务技术快速发展的条件下,对封装成服务的业务过程集成和协作的支持成为工作流描述语言的发展趋势。通过对流程协作的层次模型和场景模型的分析,提出了一种基于WfMC工作流元模型的扩展元模型,并根据该元模型对XPDL进行了相关元素扩展,得到一种支持流程集成和协作的工作流语言PS-XPDL。该语言对流程服务的协作关系及数据同步具有完备、准确的表达,同时其基于执行支持层标准协议的扩展也使得流程服务的集成及协作易于实现。  相似文献   

5.
Gathering a group of remotely located engineers to design a vehicle can be difficult, especially if they live in different countries. To overcome this obstacle, we-a team at the National Center for Supercomputing Applications (NCSA) in the US in partnership with Germany's National Research Center for Information Technology (GMD) developed a collaborative virtual prototyping system for Caterpillar. The Virtual Prototyping System (VPS) will let engineers in Belgium and the US work together on vehicle designs using distributed virtual reality. The system supports collaborative design review and interactive redesign. Integrated real-time video transmissions let engineers see other participants in a shared virtual environment at each remote site's viewpoint position and orientation. Any number of remotely located sites may join in the shared VE, communicating via multicast. The system has been tested with three sites at NCSA  相似文献   

6.
Recently, workflow technologies have been increasingly used in scientific communities. Scientists carry out research by employing scientific workflows to automate computing steps, analyze large data sets and integrate distributed computing processes. This is a challenging task because of insecure procedures in a distributed environment. In this paper, we present an access control framework and models for supporting secure and reliable collaboration. The proposed approaches combine control flows and data flow models to describe scientific workflows, and extend the atomicity sphere concept by considering two levels of atomicity abstraction at the level of process as well as at the level of data, in order to maintain the process consistency and the data consistency in the presence of failures. We also present a case study in a scientific research scenario to show the effectiveness of our approaches.  相似文献   

7.
The widespread adoption of online services for performing work, home and leisure tasks enables users to operate in the ubiquitous environment provided by the Internet by managing a possibly high number of parallel (private and shared) activity contexts. The provision of awareness information is a key factor for keeping users up-to-date with what happens around them; e.g., with the operations performed by their collaborators. However, the delivery of notifications describing the occurred events can interrupt the users’ activities, with a possible disruptive effect on their emotional and attentional states. As a possible solution to the trade-off between informing and interrupting users, we defined two context-dependent notification management policies which support the selection of the notifications to be delivered on the basis of the user’s current activities, at different granularity levels: general collaboration context versus task carried out. These policies are offered by the COntext depeNdent awaReness informAtion Delivery (CONRAD) framework. We tested such policies with users by applying them in a collaboration environment that includes a set of largely used Web 2.0 services. The experiments show that our policies reduce the levels of workload on users while supporting an up-to-the-moment understanding of the interaction with their shared contexts. The present paper presents the CONRAD framework and the techniques underlying the proposed notification policies.  相似文献   

8.
There is a growing understanding of the unique ways that tabletops support effective collaboration; however, this research mostly focuses on environments in which learners work towards a single shared goal. Underpinning this perspective, either implicitly or explicitly, is the theory that collaborative learning is a process of attaining convergent conceptual change. However, this model of collaboration may not apply to all scenarios where learners are working together. In particular, informal, open-ended exploratory environments support (and often promote) shared activities where the goal may not be for all participants to emerge with a single, shared understanding. There is increased interest in understanding the efficacy of designs that support (and encourage) learners to collaborate while seeking divergent goals, ideas, and conceptions. This paper advances a framework (Divergent Collaboration Learning Mechanisms - DCLM) for recognizing and coding collaboration and divergent learning in such environments. We apply the DCLM framework to an informal tabletop environment (Oztoc) as a means of highlighting how DCLM may reveal new productive interactions environments that support divergent forms of collaboration, mentorship, and learning. Analysis of participants’ interactions within Oztoc revealed that participants who have non-aligned goals can still productively collaborate, and in many cases can provide insight and feedback that would not be possible in shared-goal activities. We conclude with an examination of how open-ended exploratory environments can support communities of practice and legitimate peripheral participation, and the importance of divergent inquiry and divergent conceptual change across a range of learning environments.  相似文献   

9.
Many augmented reality applications require accurate tracking. Existing tracking techniques require prepared environments to ensure accurate results. This paper motivates the need to pursue augmented reality tracking techniques that work in unprepared environments, where users are not allowed to modify the real environment, such as in outdoor applications. Accurate tracking in such situations is difficult, requiring hybrid approaches. This paper summarizes two 3DOF results: a real-time system with a compass — inertial hybrid, and a non-real-time system fusing optical and inertial inputs. We then describe the preliminary results of 5- and 6-DOF tracking methods run in simulation. Future work and limitations are described.  相似文献   

10.
Many recent studies show that Augmented Reality (AR) and Automatic Speech Recognition (ASR) technologies can be used to help people with disabilities. Many of these studies have been performed only in their specialized field. Audio-Visual Speech Recognition (AVSR) is one of the advances in ASR technology that combines audio, video, and facial expressions to capture a narrator’s voice. In this paper, we combine AR and AVSR technologies to make a new system to help deaf and hard-of-hearing people. Our proposed system can take a narrator’s speech instantly and convert it into a readable text and show the text directly on an AR display. Therefore, in this system, deaf people can read the narrator’s speech easily. In addition, people do not need to learn sign-language to communicate with deaf people. The evaluation results show that this system has lower word error rate compared to ASR and VSR in different noisy conditions. Furthermore, the results of using AVSR techniques show that the recognition accuracy of the system has been improved in noisy places. Also, the results of a survey that was conducted with 100 deaf people show that more than 80 % of deaf people are very interested in using our system as an assistant in portable devices to communicate with people.  相似文献   

11.
在不断衍化的互联网环境下,云服务呈现出异构分散,动态多变,数据规模庞大等特征,结合具有自主决策能力的多agent系统(MAS)来实现云服务的分配和管理近年来逐渐成为研究热点。为追踪整体效用随时间的衰减趋势从而进一步优化协同策略,在云服务Saa S层基础上,提出基于时间边际效益的协同框架——Que Ty。该框架为云服务的broker(代理)、provider(提供商)和executor(服务执行者)之间引入时间边际效益概念,并在此基础上提出通信衰减算法和选播算法,实现了对服务流程的控制,并进一步平衡了整体效用,降低了通信损耗。  相似文献   

12.
ABSTRACT

Robots and chatbots are sophisticated. Artificial intelligence (AI) is increasingly popular in the financial industry due to its ability to provide customers with cheap, efficient and personalised services. This article uses doctrinal sources and a case study to show that many banks and FinTech start-ups are investing in AI. Yet, there are a number of challenges arising from the use of AI which could undermine trust and confidence amongst consumers. This article features the issue of bias and discrimination in banking. There is evidence that algorithms discriminate against certain races and gender. Legislative gaps in the Equality Act 2010 and the General Data Protection Regime will be analysed. Ultimately, human beings are still needed to input, train and help machines to learn. Fortunately, the FCA are leading in regulating technology, from the launch of regulatory sandboxes to their co-operative collaboration with FinTech start-ups on regulatory matters. Augmented intelligence collaboration is needed to enable industry players and regulators to provide seamless regulation and financial stability. The future of AI regulation is inter-disciplinary in approach.  相似文献   

13.
Using trust for secure collaboration in uncertain environments   总被引:7,自引:0,他引:7  
The SECURE project investigates the design of security mechanisms for pervasive computing based on trust. It addresses how entities in unfamiliar pervasive computing environments can overcome initial suspicion to provide secure collaboration.  相似文献   

14.
Virtual reality (VR) can provide useful tools for a variety of applications. However, for these tools to be effective, they must be easy to use. In virtual environments (VEs), usability is impaired by poorly designed navigation systems. Insufficient realism and missing physiological orientation and motion cues impair spatial learning in desktop VEs. Capabilities for navigation in a VE are far more varied than in reality; so much greater flexibility can be offered, but designing VEs with too many options can overwhelm users. To assist designers in building effective, usable navigation systems for VEs, navigation techniques must be evaluated to identify which features actually support users in accomplishing their tasks and which features create unnecessary problems.This study evaluates navigation in two different VEs to develop recommendations for the design of navigation systems in desktop VEs. The study consists of an objective assessment of navigation control dynamics, a guideline-based evaluation and a review of data collected during two experimental studies. The findings indicate that real-world constraints, specialised navigation techniques and feedback regarding location and direction of travel are needed to support navigation in desktop VEs.  相似文献   

15.
杨涛  石琳  宋梦蝶  李守斌  王青 《计算机应用》2017,37(7):2019-2026
软件开发流程中越来越依赖各种计算机辅助软件(CAS)。在使用多种工具的情况下,会遇到开发流程不可定制、流程数据不一致和流程管理效率低等问题。针对这些问题提出了一个支持多工具协同工作的软件开发过程管理系统。通过分析软件开发过程,研究支持快速迭代、偏向流程管理的软件工程开发模式,结合工作流思想设计分层架构的软件开发过程管理系统。该系统经过严格的测试用例检测,在设计的576个测试用例下通过率达到85%,能够完成工具协同的大部分需求,包括流程可定义、保持数据一致和开发流程管理。该系统在7个软件开发组,共约200人的规模下推广试用。根据管理组、开发组和测试组的反馈结果,该系统比传统方式节省了每周例会的时间,方便了开发任务的管理,从而提高了开发效率。  相似文献   

16.
The general aim of the contributions to this special issue was to foster learning in computer supported collaborative learning environments by designing instructional interventions that enhance collaboration between learners. Scripts and external representations were used as instructional interventions to support social and cognitive processes, respectively, during collaborative learning. Although, the interventions enhanced these social and cognitive processes, beneficial effects on learning outcomes were not always found. This discussion uses cognitive load theory, particularly the expertise reversal effect, to explain these results. It is concluded that the principles from this theory which pertains to individual learning, show great promise for the design of collaborative learning environments.  相似文献   

17.
支持服务协作的工作流元模型和建模语言   总被引:5,自引:0,他引:5  
当前支持Web服务的建模语言存在着复杂度高、互操作困难和缺乏对服务协作关系的有效支持等不足。结合面向服务工作流的服务协作需求,通过扩展工作流管理联盟的相关理论,定义了面向服务工作流的过程定义元模型,并建立了其形式化模型。通过扩展XPDL定义了一种互操作性好、支持服务协作的面向服务工作流建模语言(SoXPDL)。  相似文献   

18.
The study focuses on the implementation of information technology (IT) for supporting collaboration in distributed organizations, i.e. organizations consisting of two or more semi-autonomous units in different geographical locations. Six case studies of IT implementation projects have been conducted, focusing on the challenges in the implementation process as seen from the perspective of the implementation team. Being of an exploratory nature, the study has identified a large number of issues that have influenced the different stages in the implementation process. The implementation context studied is found to imply several additional challenges for the implementation team, compared to ‘traditional’ intra-organizational IT implementation. This is a result of greater autonomy among the participating units, heterogeneous technological platforms and logistical barriers in the implementation activities. Resistance from the organizational units, technological incompatibility and lack of incentives for adopting new work practices, are identified as major barriers in the implementation. In general, the implementation is found to require a process of maturation, where implementers and adopters gradually develop an understanding of how the technology can support the organizational needs.  相似文献   

19.
Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.  相似文献   

20.
One of the major problems in automotive assembly consists in achieving alignment within the specified tolerances between car panels that make up the exterior bodywork. To reduce errors and time requested to perform the assigned assembly tasks, workers should be guided during these panel fitting operations. Augmented Reality (AR) could be particularly suitable in this regard, as it represents one of the most promising tools to support personnel, with constantly growing applications in production processes. Following this trend, the present work aims to present an AR prototype system for supporting the operator during panel fitting operations of car body assembly, by providing instructions to correct alignment errors in terms of gap and flushness. A real case study concerning the fine alignment of car body panels with respect to the front light projector is also presented.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号