• ETRI Journal
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• v.8 no.3
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• pp.89-96
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• 1986

TDX-1의 원격교환장치(RSS)는 본체의 가입자 rack을 원격지에서 동작될수 있도록 하기 위해 정합부분을 추가하여 개발한 것이다. 본체와 RSS간의 데이터링크는 본체의 T-bus와 RSS내의 T-bus를 가상 연결시켜 IPC통신을 수행할 수 있도록 하는 기능이다.

• Convergence Security Journal
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• v.23 no.5
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• pp.21-27
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• 2023

In the cloud computing environment, servers and applications can be set up within minutes, and recovery in case of fail ures has also become easier. Particularly, using virtual servers in the cloud is not only convenient but also cost-effective compared to the traditional approach of setting up physical servers just for temporary services. However, most of the und erlying networks and security systems that serve as the foundation for such servers and applications are primarily hardwa re-based, posing challenges when it comes to implementing cloud virtualization. Even within the cloud, there is a growing need for virtualization-based security and protection measures for elements like networks and security infrastructure. This paper discusses research on enhancing the security of cloud networks using network virtualization technology. I configured a secure network by leveraging virtualization technology, creating virtual servers and networks to provide various security benefits. Link virtualization and router virtualization were implemented to enhance security, utilizing the capabilities of virt ualization technology. The application of virtual firewall functionality to the configured network allowed for the isolation of the network. It is expected that based on these results, there will be a contribution towards overcoming security vulnerabil ities in the virtualized environment and proposing a management strategy for establishing a secure network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.637-638
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• 2014

This paper proposes a new visualization method based on Vitualization technique which uses internal relationship of user correlation and external information of social network to visualize user relationship hierarchy. The proposed method use hadoop on virtual machine of OpenStack for distribution and parallel processing which the result of calculation visualizes hierarchy graph to analyze link nodes of Social Network Services for users.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.66-75
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• 2006

This paper addresses the implementation of FTTH system based on Ethernet PON technololy. This system consists of OLT and ONT. OLT supports the maximum 24 Gigabit Ethernet interfaces, and then has the flexibility and the scalability for supplying digital communication and broadcasting convergence service in the near future. OLT system consists of switch module, subscriber module, processor module, and E-PON link module, and has the operating system based on Linux. ONT is installed in customer premise to supply both IP-TV and Internet service. Also ONT has the dedicated interface for IP-TV to improve the transmission characteristics of IP-TV signal. We measure the performance of E-PON MAC through this system and then QoS control characteristics per franc in ONT by separating the virtual link for IP-TV from that for data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.517-526
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• 2006

In order to achieve high capacity and reliable link quality in wireless communication, the significant efforts should be concentrated on mitigating interference between cells. To solve the interference problem, the newly introduced concept of a Distributed Wireless Communication System (DWCS) can provide the capability of joint control of the signals at multiple cells. This paper proposes a new concept of virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. The proposed system manages two kinds of virtual cell. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The proposed system constructs DVC by using antenna selection method. Also, for multi-user high-rate data transmission, the proposed system introduces multiple antenna technology to get a spatial and temporal diversity gam and exploits space-Time Trellis Codes known as STTC to increase a spectral efficiency.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.107-117
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• 2020

With the recent development of autonomous vehicles, various sensors installed in vehicles have become common, and big data generated from those sensors is increasingly being used in the transportation field. In this study, we proposed a grid index method to efficiently process real-time vehicle sensing big data and public data such as road weather. The applicability and effect of the proposed grid space division method and grid ID generation method were analyzed. We created virtual data based on DTG data and mapped to the road link based on coordinates. As a result of analyzing the data processing speed in grid index method, the data processing performance improved by more than 2,400 times compared to the existing link unit processing method. In addition, in order to analyze the efficiency of the proposed technology, the virtually generated data was mapped and visualized.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.455-461
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• 1999

In this paper, we present the 3DOF force-rei1ecting interface which allows to acquire force of objc'Ct within a a virtual environment. This system is comlxlsed of device, virtual environment model, and force-rei1ecting r rendering algorithm. We design a J DOF force reflecting device using the pc$\alpha$allel linkage, torque shared by W wire, and the controller of system applied by impedance control algorithm. The force reflecting behaviour i implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. E Especially how force should be supplied to user, we know using a God-Object algorithm As we experiment a system implement$\varepsilon$d by the interface of 3D virtual object and 3DOF force reJll'Cting i interface, we can feel a contact, non contact of :)D virtual object surface and sensin앙 of push button model.utton model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.14-19
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• 1998

The purpose of our study is to develop tool kits which give us inexpensive simulation method. We develop a Programmable Logic Controller (PLC) program module with which we can edit and monitor PLC program, a virtual PLC (VPLC) system and simulation equipment. The PLC and simulation equipment are interlinked each other and controlled by the PLC program in real time. So, e can get effect as actural operation. Using our new tool kits we don't have to prepare PLC and machine, because we can configure PLC system and see the response of virtual machine n monitor. For validity of the developed program, we make experiments for the PLC program of elevator and automatic materials weighting system. The experimental results show that the virtual machine (VM) operates properly by the PLC control program.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.171-179
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• 2005

This paper presents the algorithm using fuzzy inference that preestimates each link speed changed by different kinds of road situations. The elements we are considered are time zone, rainfall probability information and lane control information. This paper is consists of three parts. First of all we set up the fuzzy variables, and preestimate link speed changed by various road situations. For this process, we build the membership functions for each fuzzy variable and establish the fuzzy inference relations to find how fuzzy variables influence on link speed. Second, using backtracking method, we search the shortest route influenced by link speed changed by fuzzy inference. Third, we apply this algorithm to hypothetical network and find the shortest path. As a result, it is shown that this algorithm choose appropriate roundabout path according to the changing road situations.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.45-52
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• 2009

In this paper, we develop queueing network models of communication networks with reliability model considering link failures. The reliability of a communication network with a virtual connection exposed to link failures is analyzed. Stochastic Reward Nets (SRN) is an extension of stochastic Petri nets and provides compact modeling facilities for system analysis. To get the performance index, appropriate reward rates are assigned to its SRN. It is shown that SRN modeling is well suited to specify, automatically generate and solve for reliability under rerouting. Markov models using SRN are developed and solved to depict various rerouting caused by link failures and reliability analysis in communication networks.