• Title/Summary/Keyword: multi-input

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Study of Multi Function RF Module Using Amplifier and Multiplier (증폭기 및 체배기를 이용한 다기능 RF 모듈에 관한 연구)

  • Kim, Tae-Hoon;Joo, Jae-Hyun;Koo, Kyung-Heon
    • Journal of Advanced Navigation Technology
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    • v.14 no.3
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    • pp.391-396
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    • 2010
  • This paper presents some important research result comparisons for multi function RF modules which use amplifier or frequency multiplier. By using multiplier, multi function module can be realized amply in comparison to multi band module which has separate block for each frequency band. Some com paring analysis among the switching method between separate amplifier and multiplier, the structure using frequency selective reflector, and the module using the defected ground structure. The multi function module which operates as amplifier or multiplier with input frequency is developed and input frequency suppression and output harmonics suppression can be improve d by using defected ground structure.

Nonlinear Excitation Control Design of Generator Based on Multi-objective Feedback

  • Chen, Dengyi;Li, Xiaocong;Liu, Song
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2187-2195
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    • 2018
  • In order to realize the multi-objective control of single-input multi-output nonlinear differential algebraic system (NDAS) and to improve the dynamic characteristics and static accuracy, a design method of nonlinear control with multi-objective feedback (NCMOF) is proposed, the principium of this method to arrange system poles, as well as its nature to coordinate dynamic characteristics and static accuracy of the system are analyzed in detail. Through NCMOF design method, the multi-objective control of the system is transformed into linear space, and then it is effectively controlled under the nonlinear feedback control law, the problem to balance all control objectives caused by less input and more output of the system thus is solved. Applying NCMOF design method to generator excitation system, the nonlinear excitation control law with terminal voltage, active power and rotor speed as objective outputs is designed. Simulation results show that NCMOF can not only improve the dynamic characteristics of generator, but also damp the mechanical oscillation of a generator in transient process. Moreover, NCMOF can control the terminal voltage of the generator to the setting value with no static error under typical disturbances.

English Performance of MIMO-OFDM Combing Bemaformer with Space-time Decoder in Multiuser Environments (다중 사용자 환경에서 빔 형성기와 결합된 Space-Time decoder을 가진 MIMO-OFDM 시스템의 성능)

  • Kim Chan-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.8A
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    • pp.775-783
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    • 2006
  • In this paper, the new technique combining beamforming with space-time coding is proposed for an orthogonal frequency division multiplexing(OFDM) system with multi-input multi-output(MIMO). When MIMO-OFDM system is employing Nt(the number of transmitterantenna) beamfomers and one S-T decoder at Nr receiver antennas, Nt signals removed CCI are outputted at the beamformer and then diversity gain can be got through space-time decoding. As the proposed technique can reduce cochannel interference and get diversity gain in the multi-user environment, the performance of MIMO-OFDM system is very improved. BER performance improvement and convergence behavior of the proposed approach are investigated through computer simulation by applying it to MIMO-OFDM system in the multi-user environment.

Generation and Preliminary Design of Compound Multi-Stage Gear Drive Mechanisms (복합 다단 기어장치 메커니즘의 생성 및 초기설계)

  • 정태형;김장수;박승현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.53-58
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    • 2003
  • In recent years, the need for multi-stage gear drives, which highly reduce output speed, has been increased. However, the design of multi-stage gear drives have been carried out by a limited number of experts. The consideration for the direction of input and output axes also makes their design very difficult. The purpose of this study is to develop an algorithm for automatically generating complex multi-stage gear drives and to implement a design supporting system for multi-stage gear drives. There are 4 stages in the proposed algorithm, and major design parameters,.such as the direction of input and output axes, reduction ratio, etc. are set up in the first stage. In the second stage, all mechanisms are generated, and various rules are applied to select feasible mechanisms. In the third stage, the gear ratio of each stage is divided from total gear ratio. Next, the specifications of gears for feasible mechanisms are calculated and their bending strength and surface durability are estimated. In the forth stage, appraised indexes are calculated and provided to support the estimation of the generated gear drives.

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Development of Multi-Input Multi-Output Control Algorithm for Adaptive Smart Shared TMD (적응형 스마트 공유 TMD의 MIMO 제어알고리즘개발)

  • Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.15 no.2
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    • pp.105-112
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    • 2015
  • A shared tuned mass damper (STMD) was proposed in previous research for reduction of dynamic responses of the adjacent buildings subjected to earthquake loads. A single STMD can provide similar control performance in comparison with two traditional TMDs. In previous research, a passive damper was used to connect the STMD with adjacent buildings. In this study, a smart magnetorheological (MR) damper was used instead of a passive damper to compose an adaptive smart STMD (ASTMD). Control performance of the ASTMD was investigated by numerical analyses. For this purpose, two 8-story buildings were used as example structures. Multi-input multi-output (MIMO) fuzzy logic controller (FLC) was used to control the command voltages sent to two MR dampers. The MIMO FLC was optimized by a multi-objective genetic algorithm. Numerical analyses showed that the ASTMD can effectively control dynamic responses of adjacent buildings subjected to earthquake excitations in comparison with a passive STMD.

Performance Evaluation of MIMO system by phase difference in underwater channel (수중통신환경에서 위상 차이에 따른 MIMO 시스템 성능 평가)

  • Park, Gun-yeol;Park, Tae-doo;Jung, Ji-won;Park, Sun;Choi, Myung Su;Lee, Sung Ro
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.402-404
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    • 2013
  • The wireless communication channel different speed by depth of water or salt and it is influenced by multi-path according underwater. In the paper, MIMO(Multi-input-Multi-Output) system used turbo Equalizer combining Equalizer with Turbo codes for data rates by multi-path channel. we proposed and simulated that the Decision-Directed method used for phase offset. The simulation of proposed method show that the bit-error rate performance can be severely affected by phase errors.

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Generation and Preliminary Design of Compound Multi-Stage Gear Drive Mechanisms (복합 다단 기어장치 메커니즘의 생성 및 초기설계)

  • Chong Tae-Hyong;Kim Jang-Soo;Park Seung-Hyun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.4
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    • pp.41-48
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    • 2005
  • In recent years, the need for multi-stage gear drives which highly reduce output speed has been increased. However, the design of multi-stage gear drives has been carried out by a limited number of experts. The consideration for the direction of input and output axes also makes their design very difficult. The purpose of this study is to develop an algorithm for automatically generating complex multi-stage gear drives and to implement a design supporting system for multi-stage gear drives. There are 4 stages in the proposed algorithm, and major design parameters, such as the direction of input and output axes, reduction ratio, etc. are set up in the first stage. In the second stage, all mechanisms are generated, and various rules are applied to select feasible mechanisms. In the third stage, the gear ratio of each stage is divided from total gear ratio. Next, the specifications of gears for feasible mechanisms are calculated and their bending strength and surface durability are estimated. In the forth stage, appraised indexes are calculated and provided to support the estimation of the generated gear drives.

Quantitative Assessment of Input and Integrated Information in GIS-based Multi-source Spatial Data Integration: A Case Study for Mineral Potential Mapping

  • Kwon, Byung-Doo;Chi, Kwang-Hoon;Lee, Ki-Won;Park, No-Wook
    • Journal of the Korean earth science society
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    • v.25 no.1
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    • pp.10-21
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    • 2004
  • Recently, spatial data integration for geoscientific application has been regarded as an important task of various geoscientific applications of GIS. Although much research has been reported in the literature, quantitative assessment of the spatial interrelationship between input data layers and an integrated layer has not been considered fully and is in the development stage. Regarding this matter, we propose here, methodologies that account for the spatial interrelationship and spatial patterns in the spatial integration task, namely a multi-buffer zone analysis and a statistical analysis based on a contingency table. The main part of our work, the multi-buffer zone analysis, was addressed and applied to reveal the spatial pattern around geological source primitives and statistical analysis was performed to extract information for the assessment of an integrated layer. Mineral potential mapping using multi-source geoscience data sets from Ogdong in Korea was applied to illustrate application of this methodology.

Performance Analysis of a UWB System with MIMO Antennas in Indoor Channel Environments (실내 환경의 채널에서 MIMO 안테나로 구성된 UWB 시스템의 성능 분석)

  • Kim Su-Nam;Kang Dong-Wook;Kim Ki-Doo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.11C
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    • pp.1564-1572
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    • 2004
  • UWB(Ultra Wide Band) under standardization for WPAN has a restriction in transmitting power because of interference with existing systems. To overcome the restriction, in this paper, we construct the MIMO(Multi-input-Multi-Output) channel using multi-transmit/receiver antennas and analyze the performance of the proposed system. In addition, through numerical simulation, we obtain the interference property among these antennas and analyze the effect of an interference to the system. The proposed UWB system has a ML detector and the least square method will be used to cancel the multi-user interference and the inter symbol interference caused by multipath.

Development of Auto-tuning Temperature Controller with Multi-channel (다중채널을 갖는 오토튜닝 온도 제어기 개발)

  • Lee, Kap Rai
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.4
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    • pp.419-427
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    • 2018
  • This paper designs and develops auto-tuning temperature controller with multi-channel, which controller with multi-channel could control a number of control system simultaneously. This controller has multi-channel input and output. And a number of control algorithms run in this controller simultaneously and independently. Firstly we present design method of controller with multi-channel. Secondly we design electrical circuit of sensor input, controller output and power control for temperature control board. And finally we design data protocol for serial communication to monitor control state and present verification of temperature controller with muiti-channel through field experiment.