• Title/Summary/Keyword: 모델 축소

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Small-scaled Experiment of Ship Power System with Real-time Simulator (실시간 시뮬레이터를 이용한 선박 전력 시스템의 축소 모델 실험)

  • Ko, Sanggi;Kim, So-Yeon;Choe, Sehwa;Sul, Seung-Ki
    • Proceedings of the KIPE Conference
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    • 2013.11a
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    • pp.204-205
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    • 2013
  • 선박 전력 시스템 설계에 관한 연구의 경우 실제 선박에서의 실험의 어려움 때문에 디지털 시뮬레이션에 의존해 연구를 진행해 왔다. 본 논문에서는 선박 전력 시스템의 보다 정밀한 실험 및 제어 알고리즘 검증을 위해 축소 모델과 실시간 시뮬레이터를 동시에 이용하는 새로운 실험 방법을 제안하였다. 실제 크기의 선박 전력 시스템은 직접 제작하기 어렵기 때문에 축소 모델을 이용하였고 복잡한 선박 전력 시스템의 일부를 실시간 시뮬레이터로 모의함으로써 실제 실험 세트의 구성을 간소화 할 수 있었다. 축소 모델 실험을 통해 선박 전력 시스템의 과도 상태 및 정상 상태 해석을 수행하였으며 이러한 시스템에서 얻은 결과는 추후 실선 제작을 위한 설계 자료로 활용될 수 있다.

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A Study on the Measurement and the Analysis of Radar Cross Section of the Scaled Aircraft Model (축소형 항공기 모델의 레이다 단면적 분석 및 측정에 대한 연구)

  • Kim, Ki-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1055-1060
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    • 2020
  • This study is a study on the analysis and measurement of the radar cross-sectional area of a miniature aircraft. Radar cross-sectional area for miniature aircraft in advance were analyzed using an electromagnetic analysis tool, and an actual miniature aircraft was manufactured and measured in an anechoic chamber. When measuring, the old model was used as reference data for RCS(radar cross section) characteristics and applied to the test result data of the actual reduced model. The measurement method improved the accuracy of the measurement by applying time gating to remove the influence on the components scattered inside the anechoic chamber. The RCS test results of the reduced model showed relatively high RCS characteristics in the microwave band, as the previous analysis results. In the future, we plan to utilize the method of RCS analysis and measurement for the target of the radar in the VHF(Very High Frequency)/UHF(Ultra High Frequency) band with a relatively large wavelength.

Direct Design Sensitivity Analysis of Frequency Response Function Using Krylov Subspace Based Model Order Reduction (Krylov 부공간 모델차수축소법을 이용한 주파수응답함수의 직접 설계민감도 해석)

  • Han, Jeong-Sam
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.2
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    • pp.153-163
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    • 2010
  • In this paper a frequency response analysis using Krylov subspace-based model reduction and its design sensitivity analysis with respect to design variables are presented. Since the frequency response and its design sensitivity information are necessary for a gradient-based optimization, problems of high computational cost and resource may occur in the case that frequency response of a large sized finite element model is involved in the optimization iterations. In the suggested method model order reduction of finite element models are used to calculate both frequency response and frequency response sensitivity, therefore one can maximize the speed of numerical computation for the frequency response and its design sensitivity. As numerical examples, a semi-monocoque shell and an array-type $4{\times}4$ MEMS resonator are adopted to show the accuracy and efficiency of the suggested approach in calculating the FRF and its design sensitivity. The frequency response sensitivity through the model reduction shows a great time reduction in numerical computation and a good agreement with that from the initial full finite element model.

A Study on the Similitude of member Behavior for Small-Scale Modeling of Reinforced Concrete Structure (철근콘크리트 축소모델의 부재거동 상사성에 관한 연구)

  • 이한선;장진혁
    • Magazine of the Korea Concrete Institute
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    • v.8 no.3
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    • pp.177-185
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    • 1996
  • Four types of experiments were performed to check the similitude of member behavior between prototype and 1 /10 scale models : (1) Test of slender columns with P-$\Delta$ effect, (2) Test of short columns with and without confinement steel, (3) Test of simple beams without stirrups, and (4) 'T-beam test. Based on the results of experiments, the conclusions were made as follows : (1) The P-$\Delta$ effect of slender columns can be almost exactly represented by 1/10 scale model. (2) The effect of confinement on short columns by the hoop steel can be also roughly simulated by 1/10 scale model. (3) The failure modes of simple beams without stirrups are brittle shear failures in prototype whereas those of 1/10 scale models are the ductile yielding of tension steel followed by large diagonal tension cracking and compressive concrete failure. (4) The behaviors of prototype and 1/10 scale model in T-beams appear very similar.

Experimental Study on the Similitude of Small-Scale Models in Cyclic Lateral Behaviors of RC Shear Wall Subassemblages (RC벽식 부분구조의 반복 횡하중 거동에서의 축소모델 상사성 실험연구)

  • Lee, Han-Seon;Cho, Chang-Seok;Lee, Sang-Ho;Oh, Sang-Hoon;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.22 no.6
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    • pp.805-816
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    • 2010
  • For earthquake simulation test it is essential to make sure the similitude in behaviors between the full scale prototype and the reduced scale model. This paper presents the test results obtained through the cyclic lateral-force test, on two-story RC wall subassemblages. A lower 2-story portion of the prototype structure was selected as subassemblages. The global behavior such as the strength and ductility, and the local behavior such as flexural, shear and uplift deformation were measured. The test results of the 3 : 5 scale specimens representing the prototype were compared with those of 1 : 7 scale models. Two types of subassemblages were used: One with lintel beams and one without lintel beams. The comparison shows that 1 : 7 scale model simulated in general successfully the global and local behaviors of the prototype.

Design of Generalized Controller by Improved Model Reduction (개선된 모델 축소 방법에 의한 범용적 제어기 설계)

  • Cho, Joon-Ho;Hwang, Hyung-Su
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.5
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    • pp.1-10
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    • 2007
  • In this paper, we proposed development of improved model reduction and design of common controller using reduction model. The Algorithm of improved model reduction considered the transient response and the steady-state response in response curve. The generalized controller is designed not only to ensure specified phase margin and iso-damping property also optimized smith-predictor controller about real model using reduction model. Simulation examples are given to show the better performance of the proposed method than convention methods.

Defect Severity-based Dimension Reduction Model using PCA (PCA를 적용한 결함 심각도 기반 차원 축소 모델)

  • Kwon, Ki Tae;Lee, Na-Young
    • Journal of Software Assessment and Valuation
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    • v.15 no.1
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    • pp.79-86
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    • 2019
  • Software dimension reduction identifies the commonality of elements and extracts important feature elements. So it reduces complexity by simplify and solves multi-collinearity problems. And it reduces redundancy by performing redundancy and noise detection. In this study, we proposed defect severity-based dimension reduction model. Proposed model is applied defect severity-based NASA dataset. And it is verified the number of dimensions in the column that affect the severity of the defect. Then it is compares and analyzes the dimensions of the data before and after reduction. In this study experiment result, the number of dimensions of PC4's dataset is 2 to 3. It was possible to reduce the dimension.

Balanced Model Reduction for Linear Systems with State Delay (상태변수에 시간지연을 갖는 선형시스템의 균형화된 모델 차수 축소)

  • Yoo, Seog-Hwan
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.11
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    • pp.68-74
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    • 1998
  • This paper deals with a model reduction problem for the linear systems with state delay. After defining the controllability/observability Gramians, the concept of a balanced model for the linear systems with state delay is introduced. Based on solutions of linear matrix inequalities, the model reduction method with guaranteed error bounds is developed. In order to demonstrate the efficacy of teh suggested method, a numerical example is also performed.

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A Balanced Model Reduction for Linear Delayed Systems (시간지연시스템의 균형화된 모델차수 축소)

  • 유석환
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.5
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    • pp.326-332
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    • 2003
  • This paper deals with a model reduction for linear systems with time varying delayed states. A generalized controllability and observability gramians are defined and obtained by solving linear matrix inequalities. Using the generalized controllability and observability gramians, the balanced state space equation is realized. The reduced model can be obtained by truncating states in the balanced realization and the upper bound of model approximation error is also presented. In order to demonstrate efficacy of the suggested method, a numerical example is performed.

A Study on Composite Blade Analysis Library Development through Dimension Reduction/Recovery and Calculating Energy Release Rate (단면의 차원축소/복원해석과 에너지 해방률 계산을 위한 복합재 블레이드 해석 라이브러리 개발에 대한 연구)

  • Jang, Jun Hwan;Ahn, Sang Ho
    • Composites Research
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    • v.29 no.1
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    • pp.16-23
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    • 2016
  • In this paper, numerical results of sectional analysis, stress recovery and energy release rate were compared with the results of VABS, 3-D FEM through the blade analysis library. The result of stress recovery analysis for one-dimensional model including the stiffness matrix is compared with stress results of three-dimensional FEM. We discuss the configuration of the blade analysis library and compare verifications of numerical analysis results of VABS. Blade analysis library through dimensional reduction and stress recovery is intended to be utilized in conjunction with pre- and post-processing of the analysis program of the composite blade, high-altitude uav's wing, wind blades and tilt rotor blade.