• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.839-846
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• 1988

If we use the 2-dimensional analyzing method with the magnetic vector potential for the analysis of eddy current distribution in electric machinery, we can obtain the magnitude of eddy current but can't have the characteristic of eddy current distribution. For the settlement of this problem, we have induced the governing equation with the current vector potential and attemptted 2-dimensional analysis of eddy current distribution by finite element method. And the time domain weighted residual method is used in treatment of time differential term and we have developed the algorithm by it. And then, we analyze eddy current distributions of analytic model and aluminium disk in singlephase watt hour meter. Consequently we have verified the propriety and utility of above mentioned method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.538-543
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• 2012

The performance of the speech recognition engine is one of the most critical elements of the in-vehicle speech recognition interface. The objective of this paper is to develop an automated platform for running performance tests on the in-vehicle speech recognition engine. The developed platform comprise of main program, agent program, database management module, and statistical analysis module. A simulation environment for performance tests which mimics the real driving situations was constructed, and it was tested by applying pre-recorded driving noises and a speaker's voice as inputs. As a result, the validity of the results from the speech recognition tests was proved. The users will be able to perform the performance tests for the in-vehicle speech recognition engine effectively through the proposed platform.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.134-141
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• 2010

In this paper, we propose a scheduling algorithm to improve the performance of IEEE 802.16 based wireless mesh networks using directional antenna. The performance is presented in terms of throughput of system and delay between each node by varying number of users. The result show that proposed scheduling algorithm improving the performance by reducing the delay of mesh network system. Our work may be useful as a guideline to control the fairness between SSs for multi-hop systems such as multi-hop relay and mesh networks.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.5-8
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• 2001

We propose a realtime numeric caption recognition algorithm that automatically recognizes the numeric caption generated by computer graphics (CG) and displays the modified caption using the recognized resource only when a valuable numeric caption appears in the aimed specific region of the live sportscast scene produced by other broadcasting stations. We extract the mesh feature from the enhanced binary image as a feature vector after acquiring the sports broadcast scenes using a frame grabber in realtime and then recover the valuable resource from just a numeric image by perceiving the character using the neural network. Finally, the result is verified by the knowledge-based rule set designed for more stable and reliable output and is displayed on a screen as the converted CC caption serving our purpose. At present, we have actually provided the realtime automatic mile-to-kilometer caption conversion system taking up our algorithm f3r the regular Major League Baseball (MLB) program being broadcasted live throughout Korea over our nationwide network. This caption conversion system is able to automatically convert the caption in mile universally used in the United States into that in kilometer in realtime, which is familiar to almost Koreans, and makes us get a favorable criticism from the TV audience.

• Journal of Satellite, Information and Communications
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• v.2 no.1
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• pp.27-34
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• 2007

A mobile satellite broadcasting service including an ancillary terrestrial component (ATC) takes advantage of the satellite's inherent capability to provide broadcast service over global coverage. We consider the downlink transmission concept using ATC with space=time code (STC) for the mobile satellite communication. We do not regard ATC as simply a repeater but consider it as an antenna for STC. First transmission scenarios for an application of STC are represented. Next, we apply STC in the mobile satellite system including ATC and compare the system performance in the proposed architecture of ATC to that in the conventional structure. The simulation results are compared to the conventional downlink transmission concept for the mobile satellite broadcasting service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.828-832
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• 2005

무선 인터넷에서는 원격지 이동, 근무자의 근무지원, 무선 상거래로 그 초점이 맞추어지면서 당연히 현재 무선인터넷의 보안도 트랜잭션(transaction) 보안을 시발점으로 하고 있다. 본 논문에서는 현재 무선인터넷에서 가장 화두가 되고 있는 WPKI(Wireless Public Key Infrastructure)를 이용한 단대단(End-to-End) 시스템과 MVPN(Mobile Virtual Private Network)을 분석하고, 현재 국내에서 무선인터넷 서비스를 하고 있는 이동통신 사업자의 네트워크 환경을 분석하여, 우선적으로 이동통신망을 이용한 무선 인터넷에서의 보안 시스템에 대해 기술하고자 한다. 그리고 이동전화사업자와 단말기 업체들에 이어 종합 포털(portal)들도 호환성이 강점인 자바 기반의 ‘J2ME(Jave 2 Micro Edition)’을 사용하여 무선인터넷 플랫폼 최적화 움직임이 가속화되고 있는 추세에 맞추어, 본 논문에서는 무선 인터넷 서비스 방식 중 콘텐츠 프로그램의 서버 보관 등 타사 플랫폼과는 차별화된 서비스를 제공하기 때문에 이용자들에게 한층 더 향상된 무선인터넷 서비스를 이용할 수 있게 하는 J2ME 서비스를 기초로 한 단대단간의 보안 역할을 하는 중계보안시스템에 대해 논의하고자 하며, 향후 그 모듈의 일환으로 무선 암호 메시지 전송의 구현을 통하여 이를 현실화하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.271-273
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• 2005

많은 글로벌 기업들이 비용절감 및 효율성 증대를 위하여 RFID 시스템을 도입하거나 도입을 적극 검토 중에 있다. RFID 시스템으로부터 획득된 수많은 정보들이 기업의 업무효율을 증대시킬 수 있도록 하기 위해서는 상위 응용 서비스에서 RFID 데이터를 효율적으로 사용할 수 있도록 리더와 응용 서비스 간의 중계 역할을 할 수 있는 RFID 미들웨어의 역할이 매우 중요하다. 이러한 요구사항에 맞춰 최근 EPCglobal에서는 RFID 미들웨어인 ALE(Application Level Event)를 제시하고 있다. ALE는 RFID 리더에 의해 읽혀진 EPC 이벤트 데이터를 실시간으로 수집하여 원본 데이터의 오류를 보정한 후에 사용자와 응용 서비스의 요구에 따라 특정 이벤트 데이터를 필터링하여 보고하는 역할을 한다. 본 논문에서는 ALE의 실시간 EPC 이벤트 데이터 처리를 위한 EMS(Event Management System) 컴포넌트를 제시하며 EMS에 대한 요구사항을 분석하고 설계하였다. EMS 컴포넌트는 RFID 리더를 통해서 끊임없이 들어오는 스트링 형태의 EPC 이벤트 데이터를 블록킹 없이 수집하는 역할을 한다. 또한, RFID 리더에서 수집한 데이터의 보정 및 필요 데이터 추출을 위한 다양한 필터링 기능을 제공함으로써 수집된 데이터의 정확성을 높이며 신속한 데이터 제공을 가능하게 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.1-12
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• 2015

This paper discusses current internet interconnection issues according to radical changes of internet traffic pattern. In this context, the recovery of network investment cost for network provider becomes hot issue. For recovery issues of investment cost, there are many disputes among stake holders. Therefore, it is necessary to investigate this issues in the context of internet interconnection. Also, it is important to develop the current regulation about internet interconnection under traffic changing environments. This paper selects four issues to deal with and analyzes the present situations and problems about these issues, and provides alternatives for internet interconnection corresponding to these four issues.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.326-329
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• 2009

When a patient did emergency call, only the name of the patient and a hospital room are shown to nurse's terminal. So, it's so difficult that a nurse looks for the location of the patient. Therefore we have much time about search patient when a patient does emergency call at the other places of their hospital room. This paper proposed optimal repeater's location using SOFM and patient's location estimation using repeater's location information and RSSI database. We performed simulations on searching patient's location using location estimation algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.437-442
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• 2021

This study describes the design and implementation of power supply of dehop/rehop transponder of EQM(Engineering Qualification Model). We materialized the interface of the PLDIU and power supply of a satellite bus, and minimized the potential for the occurrence of such erroneous operation circuit ESD through the WCA of the space environment. We designed a reliable power supply through simulation for TID about space radiation and simulation of the vibration generated during it launched, and we confirmed that it satisfies the environmental test specification through the test space environment after production.