• 제목/요약/키워드: reduced model

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Identification and Robust Control of a Flexible Manipulator (유연한 매니플레이터의 시스템 동정과 강건제어)

  • 송세환;박창용
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.227-277
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    • 2000
  • This paper presents an application of Mixed-Sensitivity H$_{\infty}$ control of a flexible manipulator. Firstly the detail model transfer function is derived from system identification. The objective is to position the free end of the beam with model including uncertainties and disturbance. we derive multiplicative uncertainties based on frequency response from difference between detail model and reduced model for designing controller. Finally we compare simulation results with experimental results.

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Simplified Power System Model of the Generator with the High Speed Solid State Exciter for Dynamic Stability Studies (동태안정도연구를 위한 반도체 속응여자방식 발전소의 간이전력계통 모형)

  • 한송엽;성세진
    • 전기의세계
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    • 제24권5호
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    • pp.67-71
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    • 1975
  • A dynamic stability analysis of a large interconnected power system takes much time even though the modern large computer is used because of the high order of the system dynamic equations. By the necessity of the low order power system models, a simplified power system model of the generator with the high speed solid state exciter is developed in this paper. The usefulness of the reduced model is confirmed by comparing its eigenvalues and the transient responses with those of the original model in the single machine to infinite bus power system.

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Hybrid Case-based Reasoning and Genetic Algorithms Approach for Customer Classification

  • Kim Kyoung-jae;Ahn Hyunchul
    • Journal of information and communication convergence engineering
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    • 제3권4호
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    • pp.209-212
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    • 2005
  • This study proposes hybrid case-based reasoning and genetic algorithms model for customer classification. In this study, vertical and horizontal dimensions of the research data are reduced through integrated feature and instance selection process using genetic algorithms. We applied the proposed model to customer classification model which utilizes customers' demographic characteristics as inputs to predict their buying behavior for the specific product. Experimental results show that the proposed model may improve the classification accuracy and outperform various optimization models of typical CBR system.

A Prior Model of Structural SVMs for Domain Adaptation

  • Lee, Chang-Ki;Jang, Myung-Gil
    • ETRI Journal
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    • 제33권5호
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    • pp.712-719
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    • 2011
  • In this paper, we study the problem of domain adaptation for structural support vector machines (SVMs). We consider a number of domain adaptation approaches for structural SVMs and evaluate them on named entity recognition, part-of-speech tagging, and sentiment classification problems. Finally, we show that a prior model for structural SVMs outperforms other domain adaptation approaches in most cases. Moreover, the training time for this prior model is reduced compared to other domain adaptation methods with improvements in performance.

Voltage Source FEA for Hysteresis Motor using Preisach Model

  • Hong, Sun-Ki;Lee, Seok-Hee;Jung, Hyun-Kyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제11B권4호
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    • pp.164-168
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    • 2001
  • In this paper voltage source FEA for hysteresis motor considering magnetic hysteresis characteristics is presented. The Preisach model is used as a hysteresis model. System matrix whose unknown variables are vector potentials and currents is formulated for voltage source. The stiffness matrix is maintained constant by using M-iteration method. Therefore the calculation time and efforts are reduced with Choleski direct method. Current waveform can be calculated for arbitrary voltage vaveform considering hysteresis effects.

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A Study on the Reduction of Reaction Mechanism for the Ignition of Dimethyl Ether (디메틸 에테르 착화에 관한 반응기구 축소 연구)

  • Ryu, Bong-Woo;Park, Sung-Wook;Lee, Chang-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • 제35권1호
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    • pp.75-82
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    • 2011
  • The numerical analysis of the reduction of reaction mechanism for the ignition of dimethyl ether (DME) was performed. On the basis of a detailed reaction mechanism involving 79 species and 351 reactions, the peak molar concentration and sensitivity analysis were conducted in a homogeneous reactor model. The reduced reaction mechanism involving 44 species and 166 reactions at the threshold value $7.5{\times}10^{-5}$ of the molar peak concentration was established by comparing the ignition delays the reduced mechanism with those the detailed mechanism. The predicted results of the reduced mechanism applied to the single-zone homogeneous charge compression ignition (HCCI) engine model were in agreement with those of the detailed mechanism. Therefore, this reduced mechanism can be used to accurately simulate the ignition and combustion process of compression ignition engine using DME fuel.

Reduced Model of the PC Segmental Multispan Bridge Constructed by Free Cantilever Method for Investigation of Deflection and Member Force (캔틸레버공법 PC 세그멘탈 다경간 교량의 처짐 및 단면력 검토를 위한 축소모델에 관한 연구)

  • Lee, Jae Hoon;Lee, Myeong-Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제13권4호
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    • pp.1-13
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    • 1993
  • In design of prestressed concrete structures, structural analysis is performed normally several times for selection of adequate sectional dimension and tendon amount. Especially for precast segmental multi-span bridges. time consuming structural analysis process due to time dependent material properties and structural system change could be effectively reduced by use of a reduced-span bridge model. 5-span and 3-span bridges are selected as reduced-span models for the 10-span full bridge to investigate the acceptability in practical design. The analytical results of deflection, total moment, statical moment, and ultimate moment of the reduced span-models are compared with those of the 10-span full bridge. Application of the load factors to structural analysis for ultimate moment calculation in prestressed concrete is reviewed and a rational method is proposed.

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Effect of Faba Bean Isolate and Microbial Transglutaminase on Rheological Properties of Pork Myofibrillar Protein Gel and Physicochemical and Textural Properties of Reduced-Salt, Low-Fat Pork Model Sausages

  • Geon Ho Kim;Koo Bok Chin
    • Food Science of Animal Resources
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    • 제44권3호
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    • pp.586-606
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    • 2024
  • The study was performed to determine the effect of faba bean protein isolate (FBPI) alone or in combination with microbial transglutaminase (MTG) on the rheological properties of pork myofibrillar protein gel (MPG), and physiochemical and textural properties of reduced-salt, low-fat pork model sausages (LFMSs). The cooking yields of MPGs with MTG or FBPI alone decreased and increased, respectively. However, the combination of FBPI and MTG was similar to the control (CTL) without FBPI or MTG. Gel strength values of MPG added with both FBPI and MTG were higher than treatments with FBPI or MTG alone. The hydrophobicity values of CTL were lower than those of MPG with FBPI alone, whereas the addition of MTG decreased the hydrophobicity of MPGs. The incorporation of FBPI alone or in combination with MTG decreased sulfhydryl groups (p<0.05). Shear stress values of MPGs with MTG tended to be higher than those of non-MTG treatments at all shear rates, and the addition of FBPI into MPGs increased shear stress values. Reduced-salt (1.0%) LFMSs with FBPI alone or combined with MTG had both lower cooking loss and expressible moisture values than those of CTL and similar values to the reference sample (REF, 1.5% salt). Textural properties of reduced-salt LFMSs with FBPI or MTG were similar to those of REF. These results demonstrated that the combination of FBPI and MTG could improve the water binding capacity and textural properties of pork MPGs and LFMSs and might be suitable for application in the development of healthier meat products.

Improvement of transient response characteristics of hydraulic servo system for position control by reduced-order observer (縮小次數 觀測器에 의한 位置制御 油壓 서어보시스템의 過度應答特性 改善)

  • 이경수;이교일
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제11권6호
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    • pp.1036-1043
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    • 1987
  • The objective of this paper is to improve the transient response characteristics of hydraulic servosystem via a reduced-order observer which is modelled based upon the nonlinear hydraulic servosystem. The observer is a second order linear model and implemented using a 8 bit micro-computer. The performance of the observer-based hydraulic servosystem was investigated through the hybrid computer simulations and experiments. The result shows that the reduced-order observer can effectively improve the transient response characteristics of hydraulic servosystem.

Studies on Combustion Characteristics and Reduced Kinetic Mechanisms of Natural Gas Premixed Flames (천연가스 예혼합화염의 연소특성 및 축소반응메커니즘에 관한 연구)

  • 이수룡;김홍집;정석호
    • Transactions of the Korean Society of Automotive Engineers
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    • 제6권4호
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    • pp.166-177
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    • 1998
  • Combustion characteristics of natural gas premixed flames is studied experimently and numerically by adopting a counterflow as a flamelet model in turbulent flames. Flame speeds are measured by employing LDV, and the results show that flame speed increases linearly with strain rate, which agrees well with numerical results. Parametric dependences of extinction strain rates are studied numerically with detailed kinetic mechanism to show that the addition of ethand to a methane premixed flame makes the flame more resistant to strain rate. The effect of pressure on the extinction strain rate is that the extinction strain rate increases up to 10 atm and them decreases, which is explained by competition of chain branching H+O2=OH+O and recombination reaction H+O2+M=HO2+M. Detailed mechanism having seventy-four step is systematically reduced to a nine-step and a five-step thermal NOx chemistry is reduced to two-step. Comparison between the results of the detailed and the reduced mechanisms demonstrates that the reduced mechanism successfully describes the essential features of natural gas premixed flames including extinction strain rate and NOx production.

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