• Title, Summary, Keyword: Hybrid Region

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Mechanical Property of Ultra Fine Grained Steel Weld by Hybrid Welding (하이브리드 용접에 의한 세립강 용접부의 기계적 성질에 관한 연구)

  • Dong, H.W.;Ahn, Y.S.
    • Journal of Power System Engineering
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    • v.15 no.1
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    • pp.45-50
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    • 2011
  • The effect of Mn and Ti contents in filler wire on the microstructure and mechanical property of weld metal has been investigated after hybrid welding with ultra fine grained (UFG) steel. The microstructure and distribution of alloy compositions at the top region of weld zone were quite different with those at the bottom region after hybrid welding. The bottom region of weld zone contained higher Mn and Ti contents, and consequently the hardness of bottom region was higher than that of top region. With the increase of Mn and Ti contents in filler wire, the volume percent of acicular ferrite in weld metal decreased, and the weld zone showed higher hardness and better impact property.

Characteristics of Plantlets Redifferentiated from F1 Hybrid between Panax ginseng and Panax quinquefolius (고려인삼과 미국삼의 종간잡종으로부터 재분화된 식물체의 특성)

  • Ahn, In-Ok;Lee, Sung-Sik;Lee, Jang-Ho;Lee, Bum-Soo;In, Jun-Gyo;Yang, Deok-Chun
    • Journal of Plant Biotechnology
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    • v.33 no.1
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    • pp.45-48
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    • 2006
  • The characteristics of plantlets redifferentiated from calli of F1 hybrid between Panax ginseng and Panax quinquefolius were investigated. Growth of plantlets redifferentiated from F1 hybrid was superior to the plants redifferentiated from Korean ginseng. Stem color of plantlets redifferentiated from F1 hybrid was more purple than that from Korean ginseng and leaf color of the former was also greener than that of the latter. Chunpoong, Yunpoong and Seonweon which are belonged to Korean ginseng showed same PCR band(A), while American ginseng showed different PCR band (B) in Internal Transcribed Spacer (ITS) region. F1 hybrid exhibited both A and B PCR band which belonged to Korean ginseng and American ginseng, respectively. F1 hybrid calli and plantlets redifferentiated from F1 hybrid calli showed same PCR band with that of F1 hybrid plant in ITS region. Therefore it was confirmed that piantlets redifferentiated from F1 hybrid exhibited genetic stability in ITS region.

Fuzzy-based Hybrid Fuzzy-Sliding Mode Controller for the Speed Control of a Hydraulic Inverter Controller (유압식 인버터 제어기의 속도제어를 위한 퍼지기반 하이브리드 슬라이딩모드 제어기 설계)

  • 한권상;최병욱;안현식;김도현
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.3
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    • pp.218-226
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    • 2003
  • Due to the friction characteristics of pump, cylinder packing and passenger car, in the elevation system actuated with hydraulic inverter, there exist dead zones. which cannot be controlled by a PID controller. To overcome the drawbacks, in this paper, we propose a new hybrid fuzzy-sliding mode control scheme, which controls the controller output between a sliding mode control output and a PID control output by fuzzy control method. The proposed hybrid control scheme achieves an improved control performance by using both controllers. We first propose a design method of the hybrid controller far a hydraulic system controlled by inverters, then propose a design method of a hybrid fuzzy-sliding mode centre] scheme. The effectiveness of the proposed control scheme is shown by simulation results, in which the proposed hybrid control method yields better control performance then the PID controlled scheme, not only in the zero-crossing speed region but also in the overall control region including steady-state region.

Effect of element size in hybrid stress analysis around a hole in loaded orthotropic composites (직교이방성 재료의 구멍주위에 관한 하이브리드 응력해석시 요소크기의 효과)

  • Baek, Tae-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.10
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    • pp.1702-1711
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    • 1997
  • A numerical study for the number of terms of a power series stress function and the effect of hybrid element size on stress analysis around a hole in loaded orthotropic composites is presented. The hybrid method coupling experimental and/or theoretical inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width glass epoxy tensile plate. The tests are done by rarying the number of terms, element size and nodal locations on the external boundary of the hybrid region. The numerical results indicate that the hybrid method is accurate and powerful in both experimental and numerical stress analysis.

Pupil Detection using Hybrid Projection Function and Rank Order Filter (Hybrid Projection 함수와 Rank Order 필터를 이용한 눈동자 검출)

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.27-34
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    • 2014
  • In this paper, we propose a pupil detection method using hybrid projection function and rank order filter. To reduce error to detect eyebrows as pupil, eyebrows are detected using hybrid projection function in face region and eye region is set to not include the eyebrows. In the eye region, potential pupil candidates are detected using rank order filter and then the positions of pupil candidates are corrected. The pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using template matching, we select a pair with the smallest similarity measure as final two pupils. The experiments have been performed for 700 images of the BioID face database. The pupil detection rate is 92.4% and the proposed method improves about 21.5% over the existing method..

Hybrid Two-Dimensional Finite Element Model of Tires (타이어의 복합 이차원 유한 요소 모델)

  • Kim, Yong-Joe;Bolton, J.Stuart
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.62-67
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    • 2002
  • It has been shown that the vibrational response of a tire can be represented by a set of decaying waves, each associated with a particular cross-sectional mode shape in the region near the contact patch. Thus, it can be concluded that tires can be effectively modeled as lossy waveguides. It has also been shown that the sound radiation from tires is mainly from the region close to the contact patch. In consequence, it may be computationally efficient to analyze tire vibration and sound radiation in the region close to the contact patch by using a hybrid finite element model in which the cross-section of a tire is approximated by 2-D finite elements while an analytical wave solution is assumed in the circumferential direction of the tire. In this article. a hybrid finite element was formulated based on a composite shell model. The dispersion relations for sample structures obtained by using the hybrid FE model were then compared with those obtained by using a full, three-dimensional FE model. It has been shown that the FE analysis made using the hybrid 2-D finite elements yields results in close agreement with the three-dimensional model.

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Hybrid Pulse Width Modulation Strategy for Wide Speed Range in IPMSM with Low Cost Drives

  • Ahn, Han-woong;Go, Sung-chul;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.670-674
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    • 2016
  • The control performance of hybrid PWM inverter using a phase current measurement is presented in this paper. The hybrid PWM technique consists of space vector pulse width modulation (SVPWM) and six-step voltage control operation. The SVPWM is performed to reduce the harmonic components in the low speed region, and the six-step modulation is applied to increase the maximum speed of the IPMSM in the high speed region. Therefore, it is possible to obtain a great performance in both the low speed range and high speed range. However, the six-step modulation cannot be completely implemented, since the inverter that includes the lag-shunt sensing method has an immeasurable current region. In this paper, a quasi-six-step modulation using a modified voltage vector is proposed. The validity and usefulness of the proposed PWM technique is verified by MATLAB/Simulink and experimental results.

Bandwidth Requirement of Region-based Hybrid Architectures for Massively Multiplayer Online Games (대규모 멀티플레이어 온라인 게임을 위한 영역 기반 하이브리드 구조의 대역폭 요건)

  • Kim, Jin-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.4
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    • pp.123-130
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    • 2018
  • Many massively multiplayer online games(MMOG) use client-server architectures that have enormous server-side bandwidth requirements. In this paper, we propose a region-based hybrid game architecture that combines the advantages of client-server and peer-to-peer architectures, so that only critical events changing game state are processed by the server. In this hybrid architecture, the central server divides the game into regions and assigns a player as a regional server to distribute important updates for that region. Thus, the central server sends state updates to the players through the regional servers. All players in the same region directly exchange updates without affecting game state. This division of labor greatly reduces server bandwidth significantly and enables it to serve larger number of concurrent players. Our experiments show that the region-based hybrid architecture with three-level hierarchy scales better than the client-server architecture, saving considerable bandwidth at the central server while requiring enough bandwidth of players acting as regional servers.

DEVELOPMENT OF 2-D UNSTRUCTURED HYBRID GRID GENERATION PROGRAM USING JAVA APPLET (자바 애플릿을 이용한 2차원 혼합형 비정렬 격자 생성 프로그램의 개발)

  • Lee, J.H.;Cho, K.W.;Kim, B.S.
    • 한국전산유체공학회:학술대회논문집
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    • pp.65-70
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    • 2009
  • In this paper a hybrid grid generation program for general 2-D region is introduced. The program is developed by using JAVA programming language, and it can be used either as an application program on a local computer or as an applet in the network environment. The hybrid grid system for a 2-D problem means a combination of triangular cells and quadrilateral cells, and it can offer both of the high flexibility of triangular cells and the high accuracy and efficiency of structured-type quadrilateral cells. To accommodate a quadrilateral-cell region and a triangular-cell region into one computational domain, it is importance to take good care of the interface between two different regions so that overall good grid quality can be maintained. In this research advancing layer method(ALM) augmented by elliptic smoothing method is used for the quadrilateral-cell region and advancing front method(AFM) is used for the triangular-cell region. A special treatment technique for the interface between those two regions is also developed. The interface treatment technique is basically to prevent the propagation of small cell size due to ALM method into the triangular region and maintain the smooth transition of cell-size scale between two different regions. By applying current technique high-quality hybrid grids for general 2-D regions can be easily generated, and typical grid generation results and flow solutions are demonstrated.

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Humpback Whale Assisted Hybrid Maximum Power Point Tracking Algorithm for Partially Shaded Solar Photovoltaic Systems

  • Premkumar, Manoharan;Sumithira, Rameshkumar
    • Journal of Power Electronics
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    • v.18 no.6
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    • pp.1805-1818
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    • 2018
  • This paper proposes a novel hybrid maximum power point tracking (MPPT) algorithm combining a Whale Optimization Algorithm (WOA) and the conventional Perturb & Observation (P&O) to track/extract the highest amount of power from a solar photovoltaic (SPV) system working under partial shading conditions (PSCs). The proposed hybrid algorithm is based on a WOA which predicts the initial global peak (GP) and is followed by P&O in the final stage to achieve a quicker convergence to a GP. Thus, this hybrid algorithm overcomes the computational burden encountered in a standalone WOA, grey wolf optimization (GWO) and hybrid GWO reported in the literature. The conventional algorithm searches for the maximum power point (MPP) in the predicted region by the WOA. The proposed MPPT technique is modelled and simulated using MATLAB/Simulink for simulating an environment to check its effectiveness in accurately tracking the MPP during the GP region. This hybrid algorithm is compared with a standalone WOA, GWO and hybrid GWO. From the simulating results, it is shown that the proposed algorithm offers high tracking performance and that it increases the output power level of a SPV system under partial shading. The algorithm also verified experimentally on various PSCs.