• Title/Summary/Keyword: Digital Systems

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An Investigation of Satellite Radio Access Technology for Beyond IMT-2000 Systems

  • Kang Kunseok;Ryoo Sunheui;Kim Byoung Gi;Kim Sooyoung;Ahn Do Seob
    • Journal of Communications and Networks
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    • v.7 no.2
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    • pp.135-143
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    • 2005
  • This paper presents an investigation of satellite radio access technology for beyond IMT-2000 systems. Although we could not see any active role of a satellite system in the 3G networks, satellite system will provide strong advantages in future systems for certain applications. Because a satellite link has longer round trip delay than a terrestrial link, we need technologies that would make the satellite component especially efficient. After presenting the satellite radio interface of the 3G system, we suggest several points which need to be considered in the beyond 3G systems. We also suggest a few candidate technologies with various simulation results.

Intelligent Digital Controller Using Digital Redesign

  • Joo, Young-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.2
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    • pp.187-193
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    • 2003
  • In this paper, a systematic design method of the intelligent PAM fuzzy controller for nonlinear systems using the efficient tools-Linear Matrix Inequality and the intelligent digital redesign is proposed. In order to digitally control the nonlinear systems, the TS fuzzy model is used for fuzzy modeling of the given nonlinear system. The convex representation technique also can be utilized for obtaining TS fuzzy models. First, the analog fuzzy-model-based controller is designed such that the closed-loop system is globally asymptotically stable in the sense of Lyapunov stability criterion. The simulation results strongly convince us that the proposed method has great potential in the application to the industry.

A Study on the Application Method of Look-up Table to Color Proofing Systems (컬러교정인쇄에 대한 룩업테이블의 적용방법에 관한 연구)

  • 송경철;강상훈
    • Journal of the Korean Graphic Arts Communication Society
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    • v.18 no.1
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    • pp.35-45
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    • 2000
  • Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. However, most of the digital proofing devices have lower resolution than analog proofing systems and differ with actual color presses in the color gamuts. Therefore, proper color compensations are needed for digital color proofing in order to match colors between the proofs and the press sheets. This study shows the application method of Look-up Table to the digital color proofer of Rainbow, the analog proofer of Matchprint-II, and an actual offset press is effective on the color compensations.

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Periodic Sampled-Data Control for Fuzzy Systems;Intelligent Digital Redesign Approach

  • Kim, D.W.;Joo, Y.H.;Park, J.B.
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1492-1495
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    • 2005
  • This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the affine control scheme is employed to increase the degree of freedom; 2) the fuzzy-model-based periodic control is employed; and the control input is changed n times during one sampling period; 3) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system; but its discretization error vanishes as n approaches the infinity. 4) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

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Motor Protection and Control with Digital Protective Relays (디지털 보호 계전기를 이용한 모터 보호 및 제어)

  • 이성환;안인석
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.178-178
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    • 2000
  • In this paper, intelligent methods using digital protection relay in power management and control system is developed in order to protect power systems by means of timely fault detection during operation and control at starting for induction motor which have various load environments and capacities in power systems. The digital protective relay was designed with DSP CPU(TMS320C31) to Protect and measure more quickly and precisely. The test result on the basis of KEMCl120 and IEC60255, show that the operation time error of the digital motor protection relay is improved within $\pm$5%. Also, we can control motors at starting according to starting types with simple method as programmable sequence editor. So we can improve the demerits of high cost and much manhour for rework.

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A Study on Mobile Communication system using Stillness Image

  • Lee, Jung-Ho;Han, Dae-Mun;Kim, Yeong-Real
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2007.02a
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    • pp.35-39
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    • 2007
  • We applied digital image processing about BitMap file structure in this research and studied about digital communication system. digital record saving devices can express 'High' and 'Low' as all data. Only, digital technique that two expression methods is used into several expenditures. People and communication that are far away by development of digital technology, became smooth. We wished to make communication system taking advantage of digi-tech. This system was made for communication with disabled and normal person specially. To communication method that we are studied such BitMap file handling image communication system. The goal of this contribution is to present the overview of basic algorithms for image processing using BitMap.

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Study on the Digital Redesign Using Fuzzy Inference Systems (퍼지 추론을 이용한 디지털 재설계에 관한 연구)

  • Kwon, Oh-Kook;Chang, Wook;Joo, Young-Hoon;Park, Jin-Bae;Choi, Yoon-Ho
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.506-508
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    • 1998
  • In this paper, the optimal digital redesign is studied within the framework of fuzzy systems and dual-rate sampling control theory. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the optimal feedback gains developed in the continuous-time system, the constructed fuzzy system is converted into a continuous-time system. The developed continuous-time control law is converted into an equivalent slow-rate digital control law using the proposed digital redesign method. The digital redesign technique using a fuzzy model is employed to simulate the inverted pendulum dynamics.

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Intelligent Digital Redesign Based on Periodic Control

  • Kim Do Wan;Joo Young Hoon;Park Jin Bae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.378-381
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    • 2005
  • This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the fuzzy-model-based periodic control is employed, and the control input is changed n times during one sampling period; 2) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system, but its discretization error vanishes as n approaches the infinity. 3) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

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