• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1499-1505
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• 2012

Recently, the distributed processing system for big data has been actively investigated owing to the development of high speed network and storage technologies. In addition, virtual system that can provide efficient use of system resources through the consolidation of servers has been increasingly recognized. But, when we configure distributed processing system for big data in virtual machine environments, many problems occur. In this paper, we did an experiment on the optimization of I/O bandwidth according to the creation and placement of VMs and tasks with composing Hadoop cluster in virtual environments and evaluated the results of an experiment. These results conducted by this paper will be used in the study on the development of Hadoop Scheduler supporting I/O bandwidth balancing in virtual environments.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.161-166
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• 1999

Virtual Manufacturing System(VMS) is a computer model that represents the precise and whole structure of manufacturing systems and simulates their physical and logical behavior in operation. In this paper, a real time simulation for the virtual factory is proposed to integrate a process planning with scheduling under distributed environments. In order to communicate the information under distributed environments, we use a server/client concept using socket program and internet.

• ETRI Journal
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• v.30 no.4
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• pp.618-620
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• 2008

A distributed virtual environment (DVE) allows multiple geographically distributed objects to interact concurrently in a shared virtual space. Most DVE applications use a non-replicated server architecture, which dynamically partitions a virtual space. An important issue in this system is effective scalability as the number of users increases. However, it is hard to provide suitable load balancing because of the unpredictable movements of users and hot-spot locations. Therefore, we propose a mechanism for sharing roles and separating service regions. The proposed mechanism reduces unnecessary partitions of short duration and supports efficient load balancing.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.1-11
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• 2000

Recently, the explosive popularity of Internet gave birth to researches on Distributed Virtual Environments(DVE). They aim at providing a shared application data environment at realtime for users participating in the same application session across Internet. As more users join the session, and as more multimedia data are shared, because of network resource limitation, it is more difficult to maintain the quality of DVE, such as users' satisfaction level. Previous works mainly tried to solve the scalability, synchronization and data transport issues at the application level, with limited success. We suggest a new network centric solution, that consists of a novel network architecture and protocols upon which any large-scale DVE application can be easily developed. The performance of the proposed scheme, called GAIA, is verified by simulation.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.89-100
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• 1998

A multi-user virtual reality system supports shared environments for concurrent accesses by multiple users. The performance of these systems depends heavily on the network environments. This paper experiments an effective network model for shared virtual environments. This model has a middle layer called groups placed between the server and its clients, and the tasks of server are distributed to these groups. Using groups solves some of the problems of existing systems such as lack of scalability, message overheads, and latency due to message passing among locally communicating entities in the virtual environment. Some experiments show lower overhead than existing distributed virtual environment systems in WAN as well as LAN environments. This model also supports a method that can be used to construct application specific network environments using message handler which allows user-defined message formats.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.2
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• pp.45-50
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• 2006

Tilting technology is to tilt the train on the curve in order to minimize centrifugal force to passengers and to improve the speed within the limits of passenger's comfort and safety. According to reports from other countries, there is 15~30% speed improvement compared to the conventional trains. Recently, the advent of World-Wide-Web(WWW) and the explosive popularity of the Internet gave birth to collaborative applications which were enabled by computers and networks as their primary media. The progress of 3D computer graphics enabled collaborative applications with 3D virtual environments or distributed virtual environments. In this paper, we explain our implementation of the Share collaboration engine which is for collaboration applications based on a distributed virtual environment. The Share collaboration engine proposes a new Share network architecture for management of participants, and it provides some synchronization methods for 3D objects in virtual collaboration. TTX_PDM is an experimental application that tries to prevent wastes of human, material and time resources in networked virtual collaboration.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.141-144
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• 2003

This paper proposes the distributed virtual environment framework for collaboration between heterogeneous platforms. The proposed system consists of Client, Content Server(CS), and Reflector Server(RS). The Client is composed of VR library(VRL), Interaction Manager(IM), Distributed Interaction Manager(DIM), and Network Interface(NI). The proposed Client structure can support various display environments. The XML-based IM and DIM lets the users define and add the interactions. The proposed Server structure synchronizes the distributed interaction between heterogeneous platforms and provides transparency to the users. Therefore, the proposed framework enables the users to implement virtual collaboration environment for their tasks. Moreover, it can also be used for research and development activities between a large number of the remote users. The usefulness of the framework was verified by applying it to the virtual heritage tour system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.885-888
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• 1995

Virtual Manufacturing System(VMS) is a computer model that represents the precise and whole structure of manufacturing system and simulates their physical and logical behavior in operation. In this paper, a real time simulation for the virtual factory is proposed to integrate a process planning with scheduling under distributed environments. In order to communicate the information under distributed environment, weuse a sever/client concept and socket program. the VMS is implemented on the internet environment.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.5
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• pp.209-218
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• 2005

In this paper, we propose CIVE, context-based interactive system for heterogeneous distributed virtual environments that delivers contexts irom real world to virtual environment and vice versa. The proposed system ronsists of obi-UCAM for generating user's contexts, NAVER for managing virtual environment, and Interface for linking obi-UCAM with NAVER. The connection between real and virtual worid through context is brneficial in following ways. Firstly. CIVE Provides a personalized user interface for virtual environment according to a user profile such as identity, age and vernacular. Secondly, translating all input signals into context, it guarantees adaptive access that enables a user to exploit unencumbered input devices controlling a shared object in virtual environment even if he moves with his own device from a virtual system to another. Finally, it provides a mechanism for synchronizing distributed virtual systems that share context representing changes at remote nodes. The context reduces the inconsistency of representing the same data among heterogeneous systems. Therefore, CIVE plays an important role in implementing VR applications such as teleconference, game and entertainment.

• Korea Multimedia Society
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• v.4 no.4
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• pp.16-30
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• 2000