• 한국정보처리학회논문지
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• 제6권11S호
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• pp.3190-3198
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• 1999

Because of the rapid growth of the mobile communication, the need for the mobile internet access has grown up as well. since the current mobile communication network, however, is optimized for a voice communication system, which exclusively occupies a channel for a given time, it is not suitable for variable rate packet data. In order to support the mobile internet access, it is essential do design a reasonable packet switching network which supports the mobility. Since mobile packet network has longer latency, high speed switching and QoS are required to meet the user's requirements. In this paper, we suggest an resonable way to construct a network and its operation procedures utilizing GPRS(General Packet Radio Service) network and MPLS(Multi Protocol Label Switching) to provide a high speed switching and QoS mobile internet access. GPRS is used as a network which supports the mobility and MPLS guarantees the QoS and high speed IP protocol transmission based on the ATM switching technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.135-158
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• 2018

High-Speed vehicles can be considered as multiple mobile nodes that move together in a large-scale mobile network. High-speed makes the time allowed for a mobile node to complete a handover procedure shorter and more frequently. Hence, several protocols are used to manage the mobility of mobile nodes such as Network Mobility (NEMO). However, there are still some problems such as high handover latency and packet loss. So efficient handover management is needed to meet Quality of Service (QoS) requirements for real-time applications. This paper utilizes the cross-layer seamless handover technique for network mobility presented in cellular networks. It extends this technique to propose QoS-aware NEMO protocol which considers QoS requirements for real-time applications. A novel analytical framework is developed to compare the performance of the proposed protocol with basic NEMO using cost functions for realistic city mobility model. The numerical results show that QoS-aware NEMO protocol improves the performance in terms of handover latency, packet delivery cost, location update cost, and total cost.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.47-51
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• 1997

The high speed machining which can improve the production and quality in machining has been adopted remarkably in dietmold industry. As the speed of machine tool spindle increases, the machinability evaluation and monitoring of high speed machining is necessary. In this study, the machinability of 30, 000rpm class spindle was evaluated by using the developed tool dynamometer and the machining properties of high hardened and toughness materials in high speed were examined. Finally, the in-process monitoring technologies of tool wear were presented through the prediction by the experimental formula and pattern recognition by the neural network.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.165-170
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• 2009

The Korean high-speed rail network has been made a remarkable growth recording the world's 4th rank passenger transportation scale during last 5 years after opening the revenue service of Kyoung-bu high-speed line in 2004. However, in spite of it's outstanding growth, Korean Rail technology should meet a demand of intensive technology development in order to prepare a severe competition with an advance parties of worldwide high-speed rail technology. In this paper, the characteristics and new trend of world's rail industry was reviewed based on the most recent statistics and papers of worldwide rail network from UIC and WCR32008. In conclusion, new R&D strategy with choice an concentration for the Korean high-speed rail industry was suggested based on an analysis on the trend of evolution of the state of the art technologies in worldwide high-speed rail system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권8호
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• pp.426-430
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• 1999

In this paper, a speed sensorless algorithm for a high-speed induction motor is proposed. The proposed algorithm simply estimates rotor speed by integrating the deviation between the command current value of a controller and the real current value of the motor. To estimate rotor speed without a speed sensor, a fuzzy speed controller and a neural network speed estimator are applied. Computer simulation and implementation of the proposed system is described.

• 전기학회논문지
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• 제66권9호
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• pp.1431-1436
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• 2017

The high-speed railway of catenary system, supplies a stable electric power supply to the train by satisfying the special conditions between pantograph and trolley wire, which operates more than 250km/h mutually sliding and feeding electric lines. According to Korean Railway Standard KRS PW 0026-13 (R), the standard for the grip strength of the dropper clamp in conventional line is established, but the high-speed railway line is not yet. When the grip strength of the dropper clamp is detached from the catenary line of the high-speed railway line, various problems may occur, such as damage to the pantograph due to the collision and arcing. In this paper, it is expected to be used as a basic data for establishing the durability criteria of the high-speed railway dropper clamp by verifying the dropper clamp on the Gyeong-bu and Honam high-speed line.

• 한국철도학회논문집
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• 제11권1호
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• pp.45-53
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• 2008

본 연구는 중장기적 고속철도망 계획을 위한 투자우선순위를 전통적인 평가기법에서 벗어나 지속가능 한 교통의 관점에서 이를 분석할 수 있는 방법론을 제안하고, 다원-개준 의사결정기법 중의 하나인 다원-속성 효용이론(MAUT)을 이용하여 이를 분석하였다. 지속가능 한 교통지표는 경제지표, 사회지표 및 환경지표로 구분하였으며, 지속가능 한 고속철도망 지수 분석 결과 경부와 호남 고속철도 이후에 건설되어야 할 우리나라의 고속철도망 노선축의 투자우선순위는 동서축, 남해축, 서해축 등의 순서로 분석되었다.

• 대한임베디드공학회논문지
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• 제10권1호
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• pp.25-31
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• 2015

The quality of medical treatment can be promoted by transmitting high-definition medical images and sharing these images. The high speed transmission network is a requirement for the ultra high-definition media. A high quality medical research and education can be provided by connecting resources and media-data through the superhigh speed research network. Network bandwidth for 4K media transmission generated with Lambda network technology.

• 천문학논총
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• 제20권1호
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• pp.63-71
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• 2005

e-VLBI was invented to enhance the efficiency of VLBI (Very-Long-Baseline Interferometry) system by transmitting the data via high speed network. Korean VLBI Network (KVN) has a plan to construct e-VLBI system named e-KVN. High speed backbone network and efficient network model are essential to implement successful e-VLBI system. This paper introduces a network model based on PC cluster technology. The present status of high speed backbone network in Korea is overviewed. We suggest that the network link via Korea Advanced Research Network (KOREN) is one of feasible way for e-KVN. We also describe the principles of e-VLBI and protocol for network transmission such as VSI-E (VLBI Standard Interface - Electronic), RTP (Real-Time Transport Protocol) and RTCP (Real-Time Transport Control protocol).

• 전력전자학회논문지
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• 제11권1호
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• pp.29-37
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• 2006

본 논문에서는 LM-FNN(learning Mechanism-Fuzzy Neural Network) 제어기를 이용하여 IPMSM 드라이브의 고성능 속도를 제어한다. 고성능제어를 위하여 신경회로망과 퍼지제어를 혼합 적용한 FNN을 설계한고 더욱 성능을 개선하기 위하여 학습 메카니즘을 이용하여 FNN 제어기의 파라미터를 갱신시킨다. 그리고 ANN(Artificial Neural Network)을 이용하여 IPMSM 드라이브의 속도 추정기법을 제시한다. 추정속도의 타당성을 입증하기 위하여 시스템을 구성하여 제어특성을 분석한다. 그리고 추정된 속도를 지령속도와 비교하여 전류제어와 공간벡터 PWM을 통하여 IPMSM의 속도를 제어한다. 본 연구에서 제시한 LM-FNN과 ANN 제어기의 제어특성과 추정성능을 분석하고 그 결과를 제시한다.