• 전력전자학회논문지
• /
• 제4권5호
• /
• pp.455-461
• /
• 1999

본 논문에서는 가상환경 내의 물체로부터 역감을 얻을 수 있는 3자유도 힘 반향 장치를 제안한다. 이 시스템은 디바이스와 가상환경의 모델과 힘 반향 렌더링 알고리즘 등으로 구성되었다. 평행링크 메커니즘과 와이어에 의한 토크전달 그리고 임피던스 제어가 가능한 제어기를 사용해 3자유도 힘 반향 역감장치(Force-reflecting device)를 설계하였다. 위치 함수만으로 계산되는 힘 반향동작은 God-Object 알고리즘을 사용했다. 3차원 가상물체와 시험 제작한 역감장치(Force-reflecting device)를 인터페이스 실험을 통해 3차원 가상물체와 접촉과 비접촉 그리고 푸쉬 버튼을 만지는 느낌을 검출하였다.

• 전자공학회논문지S
• /
• 제35S권2호
• /
• pp.1-9
• /
• 1998

ATM was adopted as the switching and multiplexing technique for BISDN which aims at transmitting traffics with various characteristics in a unified network. To construct these ATM networks, the most important aspect is the design of the switching system with high performance and different service capabilities. In this paepr, we analyze the performance of an input and output queueing switch with preemptive priority which is considered to be most suitable for ATM networks. For the analysis of an input queue, we model each input queue as two separate virtual input queues for each priority class and we approximage them asindependent Geom/Geom/1 queues. And we model a virtual HOL queue which consists of HOL cells of all virtual input queues which have the same output address to obtain the mean service time at each virtual input queue. For the analysis of an output quque, we obtain approximately the arrival process into the output queue from the state of the virtual HOL queue. We use a Markov chain method to analyze these two models and obtain the maximum throughput of the switch and the mean queueing delay of cells. and analysis results are compared with simulation to verify that out model yields accurate results.

• International Journal of Precision Engineering and Manufacturing
• /
• 제4권2호
• /
• pp.71-76
• /
• 2003

A virtual machine tool (VMT) is presented in this two-part paper. In Part 1, the analytical foundation for a virtual machining system is developed, which is envisioned as the foundation for a comprehensive simulation environment capable of predicting the outcome of cutting processes. The VHT system undergoes "pseudo-real machining", before actual cutting with a CNC machine tool takes place, to provide the proper cutting conditions for process planners and to compensate or control the machining process in terms of the productivity and attributes of the products. The attributes can be characterized by the machined surface error, dimensional accuracy, roughness, integrity, and so forth. The main components of the VMT are the cutting process, application, thermal behavior, and feed drive modules. In Part 1, the cutting process module is presented. When verified experimentally, the proposed models gave significantly better prediction results than any other methods. In Part 2 of this paper, the thermal behavior and feed drive modules are developed, and the models are integrated into a comprehensive software environment.vironment.

• 한국정밀공학회지
• /
• 제18권11호
• /
• pp.74-79
• /
• 2001

In this two-part paper, a virtual machine tool (VMT) is presented. In part 1, the analytical foundation of a virtual machining system, envisioned as the foundation for a comprehensive simulation environment capable of predicting the outcome of cutting processes, is developed. The VMT system purposes to experience the pseudo-real machining before real cutting with a CNC machine tool, to provide the proper cutting conditions for process planners, and to compensate or control the machining process in terms of the productivity and attributes of products. The attributes can be characterized with the machined surface error, dimensional accuracy, roughness, integrity and so forth. The main components of the VMT are cutting process, application, thermal behavior and feed drive modules. In part 1, the cutting process module is presented. The proposed models were verified experimentally and gave significantly better prediction results than any other method. The thermal behavior and feed drive modules are developed in part 2 paper. The developed models are integrated as a comprehensive software environment in part 2 paper.

• 방송공학회논문지
• /
• 제21권2호
• /
• pp.192-199
• /
• 2016

혼합증강현실 기술은 순수 현실세계와 순수 가상세계를 제외한 증강현실과 증강 가상을 포함하여 현실세계와 가상세계를 혼합하는 내용을 다룬다. 혼합증강현실에서 현실세계에서 움직이는 라이브행동자와 실체(LAE: live actor and entity)가 3D 가상공간과 혼합하여 자연스럽게 표현될 수 있으면, 원격 3D 몰입 회의, 3D 가상 체험 교육 서비스 등이 가능하다. 따라서 본 논문에서는 LAE를 3D 가상공간에 자연스럽게 혼합하고, 서로서로 상호작용할 수 모델을 표준 제안한다. 제안한 모델을 기반으로 LAE의 혼합과 상호작용이 수행될 수 있다.

• 한국CDE학회논문집
• /
• 제15권5호
• /
• pp.343-353
• /
• 2010

Time to market and cost-efficient production are some of the challenge that manufacturing industries face. Modern methods of engineering can't help such organizations attain competitive advantage. To help these situations, MEMPHIS (Middleware for Exchanging Machinery and Product Data in Highly Immersive Systems) was introduced as an approach that enables VE (Virtual Engineering) and links engineering applications with VR (Virtual Reality) solutions. Thus an environment is provided to implement virtual design reviews and enable the application of virtual prototyping methods. However MEMPHIS could just handle Product data for virtual design review and simulation. In this paper, we newly define and develop the extended MEMPHIS that enables virtual manufacturing with Process, Resource and Plant data as well as Product data.

• 자동차안전학회지
• /
• 제14권4호
• /
• pp.60-69
• /
• 2022

Recently, the importance of simulation validation in a virtual environment for autonomous driving system validation is increasing. At the same time, interest in the advancement of the virtual driving environment is also increasing. To develop autonomous driving technology, a simulation environment similar to the real-world environment is needed. For this reason, not only the road model is configured in the virtual driving environment, but also the driving environment configuration that includes the surrounding environments -traffic, object, etc- is necessary. In this article, FMTC, which is a test bed for autonomous vehicles, is implemented in a virtual environment and advanced to form a virtual driving environment similar to that of real FMTC. In addition, the similarity of the virtual driving environment is verified through comparative analysis with the real FMTC.

• International journal of advanced smart convergence
• /
• 제11권2호
• /
• pp.44-52
• /
• 2022

The purpose of our study is to examine the influence of telepresence on cultural heritage attachment in the context of virtual museum. We determined the effect of telepresence on visitors' aesthetic and educational experiences and how these experiences affect visitors' perceptions of virtual museum service value. Moreover, we investigate the effect of perceived virtual museum service value on museum attachment and cultural heritage attachment. A total of 143 visitors were sampled through an online survey focusing on Chinese virtual museum visitors. The results show that all the paths presented significant effects. Additionally, it was found that telepresence indirectly influences cultural heritage attachment through education experience and perceived virtual museum value. The theoretical and practical implications are also provided. An important implication is that online virtual museum is essential to raise visitors' education experience and their cultural heritage attachment. Thus, virtual museum should take initiative to enhance virtual reality to ensure traditional culture education and formation their cultural heritage attachment.

• Asia pacific journal of information systems
• /
• 제22권3호
• /
• pp.53-74
• /
• 2012

A challenge in fostering virtual communities is the continuous supply of knowledge, namely members' willingness to contribute knowledge to their communities. Previous research argues that giving away knowledge eventually causes the possessors of that knowledge to lose their unique value to others, benefiting all except the contributor. Furthermore, communication within virtual communities involves a large number of participants with different social backgrounds and perspectives. The establishment of mutual understanding to comprehend conversations and foster knowledge contribution in virtual communities is inevitably more difficult than face-to-face communication in a small group. In spite of these arguments, evidence suggests that individuals in virtual communities do engage in social behaviors such as knowledge contribution. It is important to understand why individuals provide their valuable knowledge to other community members without a guarantee of returns. In virtual communities, knowledge is inherently rooted in individual members' experiences and expertise. This personal nature of knowledge requires social interactions between virtual community members for knowledge transfer. This study employs the social capital theory in order to account for interpersonal relationship factors and identity theory for individual and group factors that may affect knowledge contribution. First, social capital is the relationship capital which is embedded within the relationships among the participants in a network and available for use when it is needed. Social capital is a productive resource, facilitating individuals' actions for attainment. Nahapiet and Ghoshal (1997) identify three dimensions of social capital and explain theoretically how these dimensions affect the exchange of knowledge. Thus, social capital would be relevant to knowledge contribution in virtual communities. Second, existing research has addressed the importance of identity in facilitating knowledge contribution in a virtual context. Identity in virtual communities has been described as playing a vital role in the establishment of personal reputations and in the recognition of others. For instance, reputation systems that rate participants in terms of the quality of their contributions provide a readily available inventory of experts to knowledge seekers. Despite the growing interest in identities, however, there is little empirical research about how identities in the communities influence knowledge contribution. Therefore, the goal of this study is to better understand knowledge contribution by examining the roles of social capital and identity in virtual communities. Based on a theoretical framework of social capital and identity theory, we develop and test a theoretical model and evaluate our hypotheses. Specifically, we propose three variables such as cohesiveness, reciprocity, and commitment, referring to the social capital theory, as antecedents of knowledge contribution in virtual communities. We further posit that members with a strong identity (self-presentation and group identification) contribute more knowledge to virtual communities. We conducted a field study in order to validate our research model. We collected data from 192 members of virtual communities and used the PLS method to analyse the data. The tests of the measurement model confirm that our data set has appropriate discriminant and convergent validity. The results of testing the structural model show that cohesion, reciprocity, and self-presentation significantly influence knowledge contribution, while commitment and group identification do not significantly influence knowledge contribution. Our findings on cohesion and reciprocity are consistent with the previous literature. Contrary to our expectations, commitment did not significantly affect knowledge contribution in virtual communities. This result may be due to the fact that knowledge contribution was voluntary in the virtual communities in our sample. Another plausible explanation for this result may be the self-selection bias for the survey respondents, who are more likely to contribute their knowledge to virtual communities. The relationship between self-presentation and knowledge contribution was found to be significant in virtual communities, supporting the results of prior literature. Group identification did not significantly affect knowledge contribution in this study, inconsistent with the wealth of research that identifies group identification as an important factor for knowledge sharing. This conflicting result calls for future research that examines the role of group identification in knowledge contribution in virtual communities. This study makes a contribution to theory development in the area of knowledge management in general and virtual communities in particular. For practice, the results of this study identify the circumstances under which individual factors would be effective for motivating knowledge contribution to virtual communities.

• 한국정밀공학회지
• /
• 제23권2호
• /
• pp.15-20
• /
• 2006