• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.413-420
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• 2020

The Tactical Information and Communication Network system provides real-time multimedia services such as voice and data by utilizing the Mobile Subscriber Access Point. At this time, an external transmission path is constructed through the Low Capacity Trunk Radio and the High Capacity Trunk Radio system. The communication devices of each wireless transmission system are mounted on a tactical vehicle and a secondary battery is used to prevent a power interruption when the supply power to the tactical vehicle is transferred to the integrated power control device. In this paper, the basic design of the Wireless Power Transfer device for charging the battery of the integrated power control system of the mobile base station system using the Loading Distribution Method and checking the number of primary windings and the core material selection by the air gap through the Finite Elements Method.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.17-26
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• 2003

Mobile agent system comes into the spotlight since it contributes largely to mobile computing on distributed network environment. However, this system has a number of significant security Problems. In this Paper, we analyze suity attacks to mobile agent system Presented by NIST[3]. In order to protect this system from them, we suggest a security protocol for mobile agent system by employing R based key distribution and digital multi-signature scheme. To solve these problems described in NIST, securities for mobile agent and agent platform shouid be accomplished. Comparing with other protocols, our protocol performs both of these securities, while other protocols mentioned only one of them. Proposed Protocol satisfies simplicity of key management, providing security service such as confidentiality, integrity, authentication and preventing reputation, liveness guarantee, protection of excution-result data and preventing replay attack. Furthermore, it is designed to detect message modification immediately by verifying each step of agent execution at a corresponding server.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.1-10
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• 2007

This paper describes the development of a network-based passenger information system(PIS) which provides the convenience of the passenger of the train and heightens the effect of the subtitle service, the advertising and the shelter guidance broadcasting against the urgent event. The existing system uses VGA signal distributor in order to broadcast information with image and subtitle and voice guidance. In this paper we improve the existing system by applying the UDP and TCP/IP protocol and use a reference clock to solve a data loss and synchronization problem which occurs in this case. We also developed an XML-based subtitle authoring tool which can edit and play the subtitles with various 3D to improve the automatic guidance broadcasting and advertisement effect according to the operation schedule of the train. The system performance was evaluated through a simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.46-58
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• 2008

Naval combat management system is a kind of complex weapon systems performing naval ship's warfare mission by integrating various types of system including sensor systems, weapon systems and many kinds of communication system. Recently, there are many studies to apply commercial high-level communication middleware to naval combat system development to integrate and interoperate various kinds of heterogeneous on-board systems efficiently. An initial discovery mechanism is required for application modules to start communication with their relevant modules to apply middlware technology in developing naval combat system, which is characterized by large-scale, complex and real-time system. This paper suggests a fast hybrid discovery mechanism which combines static and dynamic discovery mechanism and confirms its adaptability by an experiment on testing environment.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.327-338
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• 2010

Complete Subtree scheme(CS) is a well known broadcast encryption scheme to perform group rekeying in a stateless manner. However, statelessness comes at a cost in terms of storage and message overhead in transmitting key material. We propose a Merged Complete Subtree scheme(MCS) to reduce the communication overhead. It is more practical to make broadcast encryption schemes in network environments with limited bandwidth resources. We define all possible subset unions for ever two subsets of CS as new subsets having own key. The modification causes more storage overhead. Nevertheless, it is possible to make the size of a header, including key materials, half using subset unions of MCS, because the size of a header depends on the number of used subsets. Our evaluation therefore shows that the proposed scheme significantly improves the communication overhead of CS, reducing by half the rekey communication cost. The proposed scheme has the advantage of rekey communication cost when the number of revoked users is significant percentage of the number of potential users. The proposed scheme is fully collusion resistant.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.103-113
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• 2008

Reducing handoff latency is essential in providing seamless multimedia service in Wireless LAN based on the IEEE 802.11 standard. Reducing authentication delay is critical in reducing handoff latency. To this end, several authentication protocols for fBst handoff have been proposed. Mishra et al. used proactive key distribution to improve the authentication delay incurred in the current standard and Park et al. proposed a new authentication protocol based on Blom's key pre-distribution scheme. In this paper, we propose an enhanced authentication protocol based on Bresson et al.'s group key protocol. If a mobile node has previously access the network, our proposed protocol only requires simple hash operations in providing mutual authentication between a mobile node and access points. Our protocol is more efficient than Park et al.'s and Mishra et al.'s technique can be used in our protocol to further enhance our protocol.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1871-1874
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• 2002

최근 인터넷 환경에서 지리 정보 서비스를 제공받으려는 사용자들의 지속적인 증가로 인해 저비용의 여러 개의 단일 노드를 고속의 네트워크로 연결하여 고성능을 제공하는 클러스터 기반의 공간 데이터베이스에 대한 연구가 활발하게 진행되고 있다. 이러한 공간 데이터베이스 클러스터에서 사용자가 요구한 공간 질의를 빠르게 처리하기 위해서는 고비용의 공간 조인 연산을 효율적으로 처리하기 위한 기법이 요구된다. 본 논문에서는 비공유 공간 데이터베이스 클러스터 환경하에서 공간 조인 연산 수행 시 효율적인 병렬 처리를 위한 영역 분할 기법 및 병렬 공간 조인 기법을 제안한다. 기존의 병렬 공간 데이터베이스 시스템에서의 분할 기반 병렬 공간 조인 기법들은 병렬로 수행할 작업 분배 및 할당과 분할 경계선 상에 존재하는 공간 객체들에 대한 중복 조인 연산 및 중복 결과 제거 등의 추가적인 연산을 해야 한다는 문제점들이 있다. 제안된 기법은 공간 릴레이션들을 일정 영역들로 분할하여 비공유 공간 데이터베이스 클러스터의 각 노드에서 중복없이 저장, 관리하도록 하며 분할 영역의 경계선 상에 위치하는 공간 데이터에 대해서만 중복 저장을 허용하여 병렬 공간 조인 연산 시 누락되는 공간 데이터가 없도록 한다. 본 기법은 공간 조인 연산 시 병렬 처리를 위한 별도의 작업 할당 과정을 거치지 않고 각 노드에서 병렬적으로 공간 조인 연산을 수행하며, 분할 경계선 상에 존재하는 공간 객체들은 여과 과정을 거쳐 한번만 공간 조인이 수행되므로 중복 결과들을 제거하기 위한 별도의 연산이 필요없는 특징을 갖는다. Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.799-804
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• 2016

Broadband powerline communication (BPLC) uses distribution lines as a medium for achieving effective bidirectional data communication along with electric current flow. As the material characteristics of power lines are not good at the communication channel, the development of power line communication (PLC) systems for internet, voice, and data services requires measurement-based models of the transfer characteristics of the network suitable for performance analysis by simulation. In this paper, an analytic model describing a complex transfer function is presented to obtain the attenuation and path parameters for a multipath power line model. The calculated results demonstrated frequency-selective fading in multipath channels and signal attenuation with frequency, and were in good agreement with the experimental results. Inductive coupling units are used as couplers for coupling the signal to the power line to avoid physical connections to the distribution line. The inductance of the ferrite core, which depends on the frequency, determines the cut-off frequency of the inductive coupler. Coupling loss can be minimized by increasing the number of windings around the coupler. Coupling efficiency was improved by more than 6 dB with three windings compared to the results obtained with one winding.

• Cross-Cultural Studies
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• v.50
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• pp.395-424
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• 2018

The purpose of this paper is to examine the current situation and background of the Russian consumer music market, where digital music sources are making great strides in the noted recent years. In addition, music storage technology, media and change are considered together in this report. Moreover, Russia is the 12th largest music market in the world. The Russian music industry is following the recent trend of the global music industry, where the digital music market is growing rapidly on many different levels. The explosive growth of the digital sound sources in Russia's music industry is attributed to the explosive increase in available consumer downloads, streaming sound source service, and the increase in the number of digital sound sources using mobile technologies due to the development of the Internet. In particular, the sales of the available and accessible streaming sound sources are expected to grow explosively by the year 2020, which is expected to account for more than 85% of total digital music sales. In other words, the spread of smartphones and the resulting changes in the lifestyle of the Russians have created these changes for the global consumer of music. In other words, the time has come for anyone to easily access music and listen to music without a separate audio or digital player. And the fact that the Russian government's strong policy on the eradication of illegal copying of music is becoming an effective deterrent, as is also the factor that led to the increase of the share of the digital sound source to increase sales in Russia. Today, the Russian music industry is leading this change through the age and process of simply adapting to the digital age. Music is the most important element of cultural assets, and it is the beneficial content, which drives the overall growth of the digital economy. In addition, if the following five improvements(First, strengthen the consciousness of the Russian people about copyright protection; Second, utilizing the Big Data Internet resources in the digital music industry; Third, to improve the monopoly situation of digital music distributors; Fourth, distribution of fair music revenues; and Fifth, revitalization of a re-investment in the current Russian music industry) are effective and productive, Russia's role and position in the world music market is likely to expand.