• Title/Summary/Keyword: electrocommunication

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Differential Demodulation of GMSK in Rayleigh fading Channels

  • Choi, Joong-Ho;Han, Young-Yeul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.2
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    • pp.137-144
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    • 1991
  • A new demodulation scheeme for differentially encoded GMSK signal is introduced and described. In the proposed differential detection method, the signal is sampled at the center of the time slot, at which the effect of the intersymbol interference is relatively smaller than the edge of the time slot. The proposed differential detector takes this adbantate. The error rate performance of the differential detector has been numerically calculated in the fast fading encountered in the land mobile radio channels. A comparison of performance with the differential detector for MSK signal is given. Finally the possibility of improving performance employing nonredudant error correction is studied.

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A on-line learning algorithm for recurrent neural networks using variational method (변분법을 이용한 재귀신경망의 온라인 학습)

  • Oh, Oh, Won-Geun;Suh, Suh, Byung-Suhl
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.1
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    • pp.21-25
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    • 1996
  • In this paper we suggest a general purpose RNN training algorithm which is derived on the optimal control concepts and variational methods. First, learning is regared as an optimal control problem, then using the variational methods we obtain optimal weights which are given by a two-point boundary-value problem. Finally, the modified gradient descent algorithm is applied to RNN for on-line training. This algorithm is intended to be used on learning complex dynamic mappings between time varing I/O data. It is useful for nonlinear control, identification, and signal processing application of RNN because its storage requirement is not high and on-line learning is possible. Simulation results for a nonlinear plant identification are illustrated.

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LQ-servo design to command following and output-disturbance rejection (명령추종과 출력측 외란제거를 위한 LQ-servo 설계)

  • Yun, Seong-O;Suh, Byung-Suhl
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.5
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    • pp.443-449
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    • 1997
  • LQ-servo design procedure introduced by Athans is a method using a partial states feedback and an output feedback in order to improve the poor performance robustness of the LQR as well as to maintain its stability robustness. Although the method guarantees good stability robustness, it is not effective in performance robustness as it does not match the singular value at low or high frequencies of the transfer matrix obtained by breaking at the plant output. This paper intends propose of a new method, using the limited behaviour of the control gain introduced by Kwakernaak and Sivan, in order to improve it does it refer to controlga introduced by kwakernaak or the new metho Anblguouls.

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A Study on the Identification of Underdamped Process Control System (과소제동 공정제어시스템의 식별에 대한 연구)

  • Seo, Byeong-Seol
    • Journal of the Korean Society for Precision Engineering
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    • v.4 no.3
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    • pp.35-43
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    • 1987
  • A new analytic method for the identification of process control system is presented. A second and a third order transfer function are considered as the estimated model function. For the second order transfer function, the new method is compared with the exisiting ones, simulation results show that the new method is superior to the existing ones. And also, In case of the third order transfer function which is difficult to analyze mathematically, system identification is tried.

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Modeling Jamming Avoidance Response of Pulse-type Weakly Electric Fish (전기물고기의 방해 회피 반응 모델링과 응용)

  • Soh, JaeHyun;Kim, DaeEun
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.10
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    • pp.924-929
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    • 2015
  • In this paper, we suggest a phase difference algorithm inspired by weakly electric fish. Weakly electric fish is a fish which generates electric field though its electric organ in the tail. The weakly electric fish search for prey and detect an object by using electrolocation. The weakly electric fish have Jamming Avoidance Response (JAR) to avoid jamming signal. One of pulse-type weakly electric fish Gymnotus carapo also have JAR to reduce the probability of coincidence of pulses. We analyze this response signal and design the phase difference algorithm. We expect that simple algorithm inspired by weakly electric fish can be used in many engineering fields.