• ETRI Journal
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• v.35 no.3
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• pp.386-396
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• 2013

A 10-Gbit/s wireless communication system operating at a carrier frequency of 300 GHz is presented. The modulation scheme is amplitude shift keying in incoherent mode with a high intermediate frequency (IF) of 30 GHz and a bandwidth of 20 GHz for transmitting a 10-Gbit/s baseband (BB) data signal. A single sideband transmission is implemented using a waveguide-tapered 270-GHz high-pass filter with a lower sideband rejection of around 60 dB. This paper presents an all-electronic design of a terahertz communication system, including the major modules of the BB and IF band as well as the RF modules. The wireless link shows that, aided by a clock and data recovery circuit, it can receive $2^7$-1 pseudorandom binary sequence data without error at up to 10 Gbit/s for over 1.2 m using collimating lenses, where the transmitted power is 10 ${\mu}W$.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.591-599
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• 2001

The paper identifies a severe form of core saturation instability in an DC/AC interaction system. It then seeks solutions to the problem by HVDC control means. This is achieved by a proper design of the Voltage Dependent Current Order Limiter (VDCOL), the Current Regulator and Timing Pulse generator. Supplementary control loops have also been introduced to result in a satisfactory performance as compared to that obtained one with the use of uncharacteristic harmonic filter on the AC side. Robustness of all the options has been demonstrated through recovery performance of the DC link in response to both I-phase and 3-phase 5 cycle faults on both rectifier and inverter commutating buses.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.552-558
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• 1993

In this paper, control of a planar two-link structurally flexible robotic manipulator executing unconstrained and constrained maneuvers is considered. The dynamic model, which is obtained by using the extended Hamilton's principle and the Galerkin criterion, includes the impact force generated during the transition from unconstrained to constrained segment of the robotic task. A method is presented to obtain the linearized equations of motion in Cartesian space for use in designing the control system. The linear quadratic Gaussian with loop transfer recovery (LQG/LTR) design methodology is exploited to design a robust feedback control system that can handle modeling errors and sensor noise, and operate on Cartesian space trajectory errors. The LQG/LTR compensator together with a feedforward loop is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• International Commerce and Information Review
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• v.7 no.2
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• pp.97-113
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• 2005

Korea has actively promoted the Comprehensive Plan for the e-Hub. The policies of Korean government could promote the e-business environment and market conditions in legal and infrastructure terms, but not much of business itself. The reason for this limited success in the e-Trade may result from the broken linkage between government policies and business strategies as well as the business and technical innovation. In this paper, we analyzes the more effective and economic solution for this recovery of broken link in terms of Metamediary. The most successful role of metamediary should compose of three functions - facilitator, collaborator and web service provider. Each of these function is clarified in more detail with the emphasis on the collaboration between the Universities and the government-supported corporations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.369-373
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• 1992

Force control of a planar two-link structurally flexible robotic manipulator is considered in this study. The dynamic model is obtained by using the extended Hamilton's principle and the Galerkin criterion. A method is pressented toobtain the linearized equations of motion in Cartesian space for use in designing the control system. The approachto solving the control problem is to use feedforward and feedback control torques. The feedforward torques maneuver the flexible manipulatro along a nominal trajectory and the feedback torques minimize any deviations from the nominal trajectory. The linear quadratic Gaussian/loop transfer recovery (LQG/LTR) design methodology is explotied to design a robust feedback control system that can handle modeling errors and sensor noise, and operates on Cartesian space trajectory errors. The Lqg/LTR compenstaor together with a feedforward ollp is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.817-824
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• 2016

A simultaneous bidirectional transceiver over a single wire has been developed in a 65 nm CMOS technology for a command and control bus. The echo signals of the simultaneous bidirectional link are cancelled by controlling the decision level of receiver comparators without power-hungry operational amplifier (op-amp) based circuits. With the clock information embedded in the rising edges of the signals sent from the source side to the sink side, the data is recovered by an open-loop digital circuit with 20 times blind oversampling. The data rate of the simultaneous bidirectional transceiver in each direction is 75 Mbps and therefore the overall signaling bandwidth is 150 Mbps. The measured energy efficiency of the transceiver is 56.7 pJ/b and the bit-error-rate (BER) is less than $10^{-12}$ with $2^7-1$ pseudo-random binary sequence (PRBS) pattern for both signaling directions.

• Journal of Industrial Technology
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• v.15
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• pp.113-122
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• 1995

By integrating WDM to OPS unit which plays an important role for the reliability of CPN, we made it possible to provide CATV, VOD, and high-speed data services simultaneously and to meet the requirements for new services in the future. For the design of optimal system, the link analysis of power budget has been performed. Also, the prototyped system has been tested with STM-1 level signals to confirm functions such as transmission, distribution, and protection. The results proved that when occurred out-of-order or recovery of ONU, the system did the pertinent switching with minimum loss for high-speed data services. Also for video distribution services, the system has distributed STM-1 level signals successfully.

• Journal of Distribution Science
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• v.14 no.10
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• pp.29-38
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• 2016

Purpose - This research examines the effects of local universities on urban regeneration to recover commercial supremacy in the original urban area and provides clear information on the "University Cooperation Project for Traditional Market." Research design, data, and methodology - The "University Cooperation Project for Traditional Market" started in 2015. This study was conducted focusing on 22 places selected in 2015 and the project content in those locations. Results - This study analyzes the link to urban regeneration and spreads the concept along with theoretical consideration of university cooperation for traditional markets. Additionally, it promotes policies to help propel the project based on characteristics of the region. Conclusions - A differentiated project should be created, with characteristics of the region reflected, and detailed programs developed and implemented resulting in meaningful achievement from the perspective of members of the local community, who may have deviated from existing perspectives. Additionally, opportunities should be established for the direct application of young consumer ideas through experimental business to regenerate the traditional market (commercial supremacy), the center of the local economic society.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.268-270
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• 2000

무선 네트웍을 기반으로 하는 모빌 컴퓨팅 기술은 빠르게 성장하고 있다. 무선 네트웍 환경은 특성상 작은 끊김과 높은 에러율 때문에 모빌 컴퓨팅에서는 비연결 수행을 하는 것이 필요하다. 수많은 개념과 이론들이 이러한 모빌 컴퓨팅 환경에서 비연결 수행기능을 제공하기 위해 제안되고 있다. 본 논문에서 마코프(Marcov) 모델링 기법을 이용하여 모빌 컴퓨팅 환경에서 비연결 수행상태를 포함한 평균 수행시간을 시뮬레이션을 통하여 측정하였다. 모빌 컴퓨팅 환경은 데이터 호딩(Data Hoarding), 비연결 수행(Disconnected operation), 정지(Stop)의 3가지 상태로 구성이 된다. 이러한 3가지 상태에서 여러 가지 입력 파라메터들(에러율(Error rate), 재연결율(Recovery rate), 호버 오버헤드(Hoarding overhead), 재연결 오보헤드(Reintegration overhead)로 전체 수행시간을 분석하였다. 이러한 분석을 통해서 모빌 컴퓨팅에서 보다 효과적인 비연결 수행을 위한 방법을 선택할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.127-129
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• 2004

대부분의 통신망 복구기법에서는 예상되는 손실에 대한 망 복구를 설계한다. 예를 들어 가장 자주 발생하는 단일 링크 손실의 경우에 대하여 100%의 복구를 보장하는 형태이다. 그러나, 예상되지 않은 손실, 즉 다중 링크의 손실과 같은 경우에는 이리 준비된 예비 자원을 가지고는 설계한대로 100% 복구를 수행할 수 없다. 이 경우에는 남아있는 예비 자원을 이용하여 손실된 트래픽의 일부만이라도 복구하여야 한다. 본 논문에서는 두 개의 링크가 동시에 손실된 경우에 트래픽의 우선순위에 기반하여 여러 단계의 계층적인 복구 견고성을 제공하여, 최상위 우선순위의 트래픽에 대해서는 100%에 가까운 복구율을 제공하는 기법을 제안한다. 제안된 기법은 단일 링크의 손실에 대비한 예비 자원만을 할당하여 다중 링크 손실의 경우에도 높은 우선순위의 트래픽에 대하여 복구 견고성을 제공한다는 점에서 그 실효성이 크다.