• Title/Summary/Keyword: hybrid systems

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Characteristics of Silver Metal-mesh Electrodes Coated by Carbon Nanotubes (탄소 나노튜브가 코팅된 은 메탈-메쉬 전극의 특성)

  • Kim, Bu-Jong;Park, Jong-Seol;Hwang, Young-Jin;Park, Jin-Seok
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.1
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    • pp.55-59
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    • 2015
  • This study demonstrates hybrid-type transparent electrodes for touch screen panels. The hybrid-type electrodes were fabricated by coating carbon nanotubes (CNTs) on metal meshes. To form the metal-meshes, thin films of silver (Ag) were deposited on glass substrates using the sputtering method and then patterned via photolithography to obtain mesh structures whose line width was $10{\mu}m$ and line-to-line spacing was $300{\mu}m$. CNTs were coated on Ag-meshes by using two different methods, such as spray coating and electrophoretic deposition (EPD). For the samples of a Ag-meshes and CNTs-coated Ag-meshes, their surface morphologies, electrical sheet resistances, and visible-range transmittances and reflectances were characterized and compared. The experimental results indicated that the reflectance of Ag-mesh electrodes was substantially reduced by coating of CNTs. Especially, the hybrid electrodes of Ag-meshes with EPD-coated CNTs showed excellent properties such as sheet resistance lower than $20{\Omega}/{\Box}$, transmittance higher than 90 %, and reflectance lower than 8%.

Hybrid Symbol Offset Estimation Algorithm for MIMO OFDM Systems (MIMO OFDM 시스템을 위한 하이브리드 심볼 옵셋 추정 알고리즘)

  • Jung, Hyeok-Koo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.4
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    • pp.461-469
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    • 2008
  • This paper proposes a hybrid symbol offset estimation algorithm for MIMO(Multiple Input Multiple Output) OFDM system. As MIMO OFDM systems are multiple transmitter and receiver antenna systems, apart from SISO(Single Input Single Output) system, it is possible to use several combining techniques which are used in multiple receive antenna system. In this paper, we propose hybrid symbol offset estimation algorithms using combining techniques in multiple receive antenna systems, simulate and show the performances in MIMO system environments. The proposed equal gain combining correlation algorithm has better performance 1.8 times in searching the ideal symbol offset rather than the conventional early symbol offset algorithm in severe ISI channel.

Performance Comparison of Molten Carbonate Fuel Cell Hybrid Systems Minimizing Carbon Dioxide Emissions (이산화탄소 배출을 최소화하는 용융탄산염 연료전지 하이브리드 시스템들의 성능 비교)

  • AHN, JI HO;YOON, SUK YOUNG;KIM, TONG SEOP
    • Journal of Hydrogen and New Energy
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    • v.28 no.1
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    • pp.30-39
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    • 2017
  • Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.

A Hybrid Malfunction Diagnostic System using Rules and Cases (규칙 및 사례기반의 하이브리드 고장진단 시스템)

  • 이재식;김영길
    • Journal of Intelligence and Information Systems
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    • v.4 no.1
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    • pp.115-131
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    • 1998
  • Customer service process is one of the most important processes in today's competitive business environment. Among the various activities of customer service process, equipment malfunction diagnosis activity should be performed fast and accurately. When a customer calls the service center and reports the observed symptoms, he/she describes them in layman's terms. Therefore, the customer-reported symptoms have not been considered helpful information for service representatives. However, in order to perform diagnosis activity fast and accurately, we need to make use of the customer-reported symptoms actively. In this research, we developed three systems called R-EMD (Rule-based Equipment Malfunction Diagnostic system), C-EMD (Case-based Equipment Malfunction Diagnostic system) and R&C-EMD (Rule & Case-based Equipment Malfunction Diagnostic system), each of which diagnoses equipment malfunctions using the customer-reported symptoms. R&C-EMD is a hybrid system that utilizes both rule-based and case-based technologies. The diagnosis rules used in R&C-EMD and R-EMD were not acquired from service manuals or interviews with service representatives. Rater, we extracted them directly from the past diagnosis cases based on symptoms' frequencies. By this way, we were able to overcome the knowledge acquisition bottleneck. Using the real 100 malfunction diagnosis cases, we evaluated the performances of R&C-EMC, R-EMD and C-EMD in terms of speed and accuracy. In diagnosis time, R&C-EMD took longer than R-EMD and shorter than C-EMD. However, R&C-EMC was the best in accuracy.

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Multi-Stage Turbo Equalization for MIMO Systems with Hybrid ARQ

  • Park, Sangjoon;Choi, Sooyong
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.333-339
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    • 2016
  • A multi-stage turbo equalization scheme based on the bit-level combining (BLC) is proposed for multiple-input multiple-output (MIMO) systems with hybrid automatic repeat request (HARQ). In the proposed multi-stage turbo equalization scheme, the minimum mean-square-error equalizer at each iteration calculates the extrinsic log-likelihood ratios for the transmitted bits in a subpacket and the subpackets are sequentially replaced at each iteration according to the HARQ rounds of received subpackets. Therefore, a number of iterations are executed for different subpackets received at several HARQ rounds, and the transmitted bits received at the previous HARQ rounds as well as the current HARQ round can be estimated from the combined information up to the current HARQ round. In addition, the proposed multi-stage turbo equalization scheme has the same computational complexity as the conventional bit-level combining based turbo equalization scheme. Simulation results show that the proposed multi-stage turbo equalization scheme outperforms the conventional BLC based turbo equalization scheme for MIMO systems with HARQ.

Hybrid Buffer Replacement Scheme Considering Reference Pattern in Multimedia Storage Systems (멀티미디어 저장 시스템에서 참조 유형을 고려한 혼성 버퍼 교체 기법)

  • 류연승
    • Journal of Korea Multimedia Society
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    • v.5 no.1
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    • pp.47-56
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    • 2002
  • Previous buffer cache schemes for multimedia storage systems only exploited the sequential references of multimedia files and didn't consider looping references. However, in some video applications like foreign language learning, users mark the scene as loop area and then application automatically playbacks the scene several times. In this paper, we propose a new buffer replacement scheme, called HBM(Hybrid Buffer Management), for multimedia storage systems that have both sequential and looping references. Proposed scheme assumes that application layer informs reference pattern of files to file system. Then HBM applies an appropriate replacement policy to each file. Our simulation experiments show that HBM outperforms previous buffer cache schemes such as DISTANCE and LRU.

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A Study on the Moment Resisting Performance of the Hybrid Beam-Column Connection System with Structural Tee (T 형강을 사용한 합성골조 보-기둥 접합부의 휨 저항성능에 관한 연구)

  • 임대성;최광호;김상식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.597-602
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    • 1998
  • The composite systems, consisting of R/C Columns-Steel Beams, are reasonable structures because of their constructional and economical advantages, workability and so on. But, it is difficult to apply the composite systems to actual design due to material dissimilarity and complicate stress flow in the connection. This study aims to propose the hybrid beam-column connection system with structural tee and through experimental research make clear the shear and moment resistance capacity and stress transfer mechanism.

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Design of Hybrid Smith-Predictor Fuzzy Controller Using Reduction Model (축소 모델을 이용한 하이브리드 스미스 퍼지 제어기 설계)

  • Cho, Joon-Ho;Hwang, Hyung-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.5
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    • pp.444-451
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    • 2007
  • In this paper, we propose an improved reduction model and a reduction model-based hybrid smith-predictor fuzzy controller. The transient and steady-state responsed of the reduction model was evaluated. In tuning the controller, the parameters of PID and the factors fuzzy controllers were obtained from the reduced model and by using genetic algorithms, respectively. Simulation examples demonstrated a better performance of the proposed controller than conventional ones.

Generation of SAC using a ASMOD and a Hybrid curve approximation (ASMOD와 혼합 곡선 근사법을 이용한 SAC의 생성)

  • 김현철;이경선;김수영
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.435-438
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    • 1997
  • This paper presents the process generating a SAC(Sectional Area Cure) by using ASMOD(Adaptive Spline Modeling of Observation Data). That is, we define SACs of real ships as B-spline curves by a hybrid cure approximation(which is the combination method of a B-spline fitting method and a genetic algorithm) and accumulate a database of control points. Then we let ASMOD learn from the correlation principal dimensions with control points.

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Application of Genetic Algorithm to Hybrid Fuzzy Inference Engine

  • Park, Sae-hie;Chung, Sun-tae;Jeon, Hong-tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.2 no.3
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    • pp.58-67
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    • 1992
  • This paper presents a method on applying Genetric Algorithms(GA), which is a well-know high performance optimizing algorithm, to construct the self-organizing fuzzy logic controller. Fuzzy logic controller considered in this paper utilized Sugeno's hybrid inference method. which has an advantage of simple defuzzification process in the inference engine. Genetic algorithm is used to find the iptimal parameters in the FLC. The proposed approach will be demonstrated using 2 d. o. f robot manipulator to verify its effectiveness.

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