• 한국전자통신학회논문지
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• 제10권10호
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• pp.1101-1108
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• 2015

본 논문은 망 분리 가상 컴퓨터 환경 제공 방법 및 시스템을 제공한다. 본 가상 컴퓨터 환경 제공 방법은 가상 기능 수행을 위해 필요한 가상 자원 요청을 생성하는 단계 및 가상 자원 등록 요청을 네트워크 프로토콜 포맷으로 변환하여 네트워크를 통해 전송하는 단계를 포함한다. 이로 인해, 등록 처리 절차가 조합형 망 분리 가상 컴퓨팅 자원 할당과 임의 시간 동안 가상 컴퓨터를 사용하기 위해서, 서버와 클라이언트 또는 휴대폰 사이에서 가능해졌다. 언제든, 인터넷에 접속해 내 컴퓨터와 동일한 환경에서 업무를 처리 할 수 있게 된다.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.615-624
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• 2001

Internet technology opens up another domain for building future CAD/CAM environment. The environment will be global, network-centric, and spatially distributed. In this paper, we present a new approach to network-centric virtual prototyping (NetVP) in a distributed design environment. The presented approach combines the current virtual assembly modeling and analysis technique with distributed computing and communication technology fur supporting virtual prototyping activities over the network. This paper focuses on interoperability, shape representation, and geometric processing for distributed virtual prototyping. STEP standard and CORBA-based interfaces allow the bi-directional communication between the CAD model and virtual prototyping model, which makes it possible to solve the problems of interoperability, heterogeneity of platforms, and data sharing. STEP AP203 and AP214 are utilized as a means of transferring and sharing product models. In addition, Attributed Abstracted B-rep (AAB) is introduced as 3D shape abstraction for transparent and efficient transmission of 3D models and for the maintenance of naming consistency between CAD models and virtual prototyping models over the network.

• 한국컴퓨터정보학회논문지
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• 제21권1호
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• pp.65-72
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• 2016

Network virtualization is an emerging technology for solving the rigidity of the physical network infrastructure. The innovative technique virtualizes all resources in the network, including the network links and nodes, and provides a number of virtual networks on a single network infrastructure. In order to realize a virtual network, a thorough and complete monitoring of all resources in the network should be performed firstly. OpenFlow is an open source stack for network virtualization. However, it is impossible to apply OpenFlow to AP-based legacy wireless LAN environment because OpenFlow targets ethernet-based LAN environment. In this paper, we implement an adaptor-styled virtual switch for AP-based wireless LAN through customizing the Open vSwitch which is a virtual switch of OpenFlow. The evaluation test results show that the implemented OpenFlow stack operates successfully. The implemented OpenFlow stack can now be plugged immediately in existing AP-based wireless LAN environment and plays network resource monitoring. In the future, we can develop wireless LAN virtualization applications on the wireless OpenFlow stack.

• 한국컴퓨터그래픽스학회논문지
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• 제3권1호
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• pp.29-36
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• 1997

기존의 많은 가상현실시스템은 단일 사용자를 위한 단일 시스템으로 개발되었다. 그러나 최근의 증가 되는 인터넷등 통신망의 이용가치로 인해 많은 사람들이 분산 가상 현실- 네트워크를 통해 다수의 참여자가 상호작용을 공유하는 가상 환경- 기술에 큰 관심을 가지게 되었다. 본 연구에서는 LAN상에서 가상환경과 상호작용을 공유하기 위해서 3차원 가상세계표현화 네트워크 모델에 관한 연구를 하였다. 상호작용이 가능한 3차원 가상세계표현은 멀티유저 환경을 지원하도록 확장한 VRML을 기반으로 하였고 네트워크 모델은 IP멀티캐스트 환경하에서 멀티유저와 상호작용을 지원하고 3차원 가상 세계를 공유하도록 하는 구조와 프로토콜로 구성되었다.

• Journal of Computing Science and Engineering
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• 제7권3호
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• pp.198-203
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• 2013

In this paper, we focus on a novel Internet architecture, based on the urbanization of virtual machines. In this approach, virtual networks are built linking specific virtual elements (router, switch, firewall, box, access point, etc.). A virtual network represents a network with an independent protocol stack that shares resources from the underlying network infrastructure. Virtualization divides a real computational environment into virtual computational environments that are isolated from each other, and interact with the upper computational layer, as would be expected from a real, non-virtualized environment. Metamorphic networks enhance several concepts related to future networks, and mainly the urbanization of virtual machines. We present this new paradigm, and the methodology, based on the worldwide metamorphic network platform "M-Net". The metamorphic approach could solve many complex problems, especially related to Cloud computing services.

• Journal of Mechanical Science and Technology
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• 제15권4호
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• pp.448-458
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• 2001

The primary goal of virtual prototyping is to eliminate the need for fabricating physical prototypes, and to reduce cost and time for developing new products. A virtual prototyping seeks to create a virtual environment where the development of a new model can be flexible as well as rapid, and experiments can be carried out effectively concerning kinematics, dynamics, and control aspects of the model. This paper addresses the virtual environment used for virtual prototyping of a passenger vehicle. It has been developed using the dVISE environment that provides such useful features as actions, events, sounds, and light features. A vehicle model including features, and behaviors is constructed by employing an object-oriented paradigm and contains detailed information about a real-size vehicle. The human model is also implemented not only for visual and reach evaluations of the developed vehicle model, but also for behavioral visualization during a crash test. For the real time driving simulation, a neural network model is incorporated into the virtual environment. The cases of passing bumps with a vehicle are discussed in order to demonstrate the applicability of a set of developed models.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.793-794
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• 2009

최근에는 컴퓨팅 자원이 크게 증가하여, 인터넷을 통해 연결된 수많은 컴퓨팅 자원들을 다수의 사용자가 이용하고 어떻게 서비스 할 것인가에 대한 클라우드 컴퓨팅 또는 그리드 컴퓨팅 기술이 주목받고 있으며 또한 네트워크에서도 물리적 네트워크 위에 가상의 네트워크 링크와 노드을 구성하여 가상의 네트워크를 구성하는 가상 네트워크 환경 연구가 이뤄지고 있다. 가상화 기술은 네트워크 보다는 실질적으로 운영체제 분야에서 오랫동안 연구되고 발전되고 있으나 본 논문에서는 네트워크 분야에 적용된 가상화기술을 토대로 모바일 네트워크에 적용된 가상 모바일 네트워크에 대하여 살펴보도록 하겠다.

• ETRI Journal
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• 제43권5호
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• pp.932-940
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• 2021

Currently, research on network functions virtualization focuses on using microservices in cloud environments. Previous studies primarily focused on communication between nodes in physical infrastructure. Until now, there is no sufficient research on group key management in virtual environments. The service is composed of microservices that change dynamically according to the virtual service. There are dependencies for microservices on changing the group membership of the service. There is also a high possibility that various security threats, such as data leakage, communication surveillance, and privacy exposure, may occur in interactive communication with microservices. In this study, we propose an ID-based group key exchange (idGKE) mechanism between microservices as one group. idGKE defines the microservices' schemes: group key gen, join group, leave group, and multiple group join. We experiment in a real environment to evaluate the performance of the proposed mechanism. The proposed mechanism ensures an essential requirement for group key management such as secrecy, sustainability, and performance, improving virtual environment security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권2호
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• pp.287-312
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• 2011

Internet chat programs and instant messaging services are becoming increasingly popular among Internet users. One of the crucial issues with Internet chat is how to manage the corresponding pairs of questions and answers in a sequence of conversations. Although many novel methodologies have been introduced to cope with this problem, most are poor in managing interruptions, organizing turn-taking, and conveying comprehension. The Internet environment is recently evolving into a 3D environment, but the problems with managing chat dialogues with the standard 2D text-based chat have remained. Therefore, we propose a more realistic communication model for chat agents in 3D virtual space in this paper. First, we propose a new method to measure the capacity of communication between chat agents and a novel visualization method to depict the hierarchical structure of chat dialogues. In addition, we are concerned with communication networks for virtual people (avatars) living in virtual worlds. In this paper we consider a microscopic aspect of a social network in a relatively short period of time. Our experiments show that our model is highly effective in a virtual chat environment, and the communication network based on our model greatly facilitates investigation of a very large and complicated communication network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4023-4043
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• 2016

Network virtualization has been regarded as a core attribute of the Future Internet. In a network virtualization environment (NVE), multiple heterogeneous virtual networks can coexist on a shared substrate network. Thus, a substrate network failure may affect multiple virtual networks. In this case, it is increasingly critical to provide survivability for the virtual networks against the substrate network failures. Previous research focused on mechanisms that ensure the resilience of the virtual network. However, the resource efficiency is still important to make the mapping scheme practical. In this paper, we study the survivable virtual network embedding mechanisms against substrate link and node failure from the perspective of improving the resource efficiency. For substrate link survivability, we propose a load-balancing and re-configuration strategy to improve the acceptance ratio and bandwidth utilization ratio. For substrate node survivability, we develop a minimum cost heuristic based on a divided network model and a backup resource cost model, which can both satisfy the location constraints of virtual node and increase the sharing degree of the backup resources. Simulations are conducted to evaluate the performance of the solutions. The proposed load balancing and re-configuration strategy for substrate link survivability outperforms other approaches in terms of acceptance ratio and bandwidth utilization ratio. And the proposed minimum cost heuristic for substrate node survivability gets a good performance in term of acceptance ratio.