• 제목/요약/키워드: proposed model

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SNA 기반 네트워크 파워를 이용한 지상전장정보체계 전투력 효과측정 모델제안 (A Proposal of Combat Power Measurement Model of Army Warfare Information System Using Network Power based on Social Network Analysis)

  • 정치영;이재영
    • 한국경영과학회지
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    • 제36권4호
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    • pp.1-16
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    • 2011
  • It is important not only to introduce the C4I(Command and Control, Communication, Computer, Intelligence) system for realizing the NCW(Network Centric Warfare) but also to evaluate the synergistic effect by the C4I system. However, the study effort for evaluating the system's synergistic effect is insufficient compared with introducing the system. Therefore, in this paper, we proposed a model that measures the synergistic effect of combat power by the warfare information system. To measure the synergistic effect of warfare information system, the network power must be considered, so we also proposed a new methodology for measurement of network power based on SNA(Social Network Analysis), not Metcalfe's law. A model we proposed is a model that measures the raised combat power by the network effectiveness. The methodology and model we proposed in this paper will be used usefully to analyze the practical effect of constructing future warfare information system.

Nyquist 선도에 의한 개선된 모델 축소 알고리즘 (Improved Model Reduction Algorithm by Nyquist Curve)

  • 조준호;최정내;황형수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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    • pp.215-218
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    • 2001
  • To improve the performance of PID controller of high order systems by model reduction, we proposed a new model reduction method in frequency domain. A new model reduction method we proposed, considered four points (${\angle}G(jw)=0$, $-{\pi}/2$, $-{\pi}$, $-3{\pi}/2$) in stead of two points (${\angle}G(jw)=-{\pi}/2$, and $-{\pi}$) in Nyquist curve. And for high order systems that it have not two point (${\angle}G(jw)=-{\pi}/2$, and $-{\pi}$) in Nyquist curve, we proposed a method to annex very small dead time. This method has a annexed very small dead time on the base model for reduction, and we cancel it after to get the reduced model. It is shown that the performance of proposed method is better than any other methods.

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2바이트 코드워드 표현방법에 의한 자료압축 알고리듬 (Data compression algorithm with two-byte codeword representation)

  • 양영일;김도현
    • 전자공학회논문지C
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    • 제34C권3호
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    • pp.23-36
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    • 1997
  • In tis paper, sthe new data model for the hardware implementation of lempel-ziv compression algorithm was proposed. Traditional model generates the codeword which consists of 3 bytes, the last symbol, the position and the matched length. MSB (most significant bit) of the last symbol is the comparession flag and the remaining seven bits represent the character. We confined the value of the matched length to 128 instead of 256, which can be coded with seven bits only. In the proposed model, the codeword consists of 2 bytes, the merged symbol and the position. MSB of the merged symbol is the comression flag. The remaining seven bits represent the character or the matched length according to the value of the compression flag. The proposed model reduces the compression ratio by 5% compared with the traditional model. The proposed model can be adopted to the existing hardware architectures. The incremental factors of the compression ratio are also analyzed in this paper.

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정적 대변형에 중첩된 미소 동적 하중을 견디는 고무재료의 점탄성 구성방정식에 관한 연구 (A viscoelastic constitutive model of rubber under small oscillatory loads superimposed on large static deformation)

  • 김봉규;윤성기
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.280-285
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    • 2000
  • A viscoelastic constitutive equation of rubber that is under small oscillatory load superimposed on large static deformation is proposed. The proposed model is derived through linearization of Simo's viscoelastic constitutive model and reference configuration transformation. The proposed constitutive equation is extended to a generalized viscoelastic constitutive equation that includes widely used Mormin's model as a special case using objective stress increment. Static deformation correction factor is introduced to consider the influence of Pre-strain on the relaxation function. The proposed constitutive model is tested fer dynamic behavior of rubber specimens with different carbon black contents. It is concluded from the test that the viscoelastic constitutive equation for filled rubber must include the influence of the static deformation on the time effects. The suggested constitutive equation with static deformation correction factor shows good agreement with test values.

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실시간 공칭 모델 추정 외란관측기에 관한 실험 연구: 재귀최소자승법 (An Experimental Study on Realtime Estimation of a Nominal Model for a Disturbance Observer: Recursive Least Squares Approach)

  • 이상덕;정슬
    • 제어로봇시스템학회논문지
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    • 제22권8호
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    • pp.650-655
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    • 2016
  • In this paper, a novel RLS-based DOB (Recursive Least Squares Disturbance Observer) scheme is proposed to improve the performance of DOB for nominal model identification. A nominal model can be generally assumed to be a second order system in the form of a proper transfer function of an ARMA (Autoregressive Moving Average) model. The RLS algorithm for the model identification is proposed in association with DOB. Experimental studies of the balancing control of a one-wheel robot are conducted to demonstrate the feasibility of the proposed method. The performances between the conventional DOB scheme and the proposed scheme are compared.

Building a Fuzzy Model with Transparent Membership Functions through Constrained Evolutionary Optimization

  • Kim, Min-Soeng;Kim, Chang-Hyun;Lee, Ju-Jang
    • International Journal of Control, Automation, and Systems
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    • 제2권3호
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    • pp.298-309
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    • 2004
  • In this paper, a new evolutionary scheme to design a TSK fuzzy model from relevant data is proposed. The identification of the antecedent rule parameters is performed via the evolutionary algorithm with the unique fitness function and the various evolutionary operators, while the identification of the consequent parameters is done using the least square method. The occurrence of the multiple overlapping membership functions, which is a typical feature of unconstrained optimization, is resolved with the help of the proposed fitness function. The proposed algorithm can generate a fuzzy model with transparent membership functions. Through simulations on various problems, the proposed algorithm found a TSK fuzzy model with better accuracy than those found in previous works with transparent partition of input space.

EGR 밸브 액추에이터 모델링 (Modeling of EGR Valve Actuator)

  • 서은성;신휘범
    • 전력전자학회논문지
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    • 제22권5호
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    • pp.390-396
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    • 2017
  • In this paper, an exact mathematical model is derived for an exhaust gas recirculation (EGR) valve actuator driven by an H-bridge converter. Particularly, a spring torque model of the EGR valve is proposed. The spring torque model is proposed by converting spring force and Coulomb frictional force in linear motion into a rotational torque. Moreover, a mechanical end-stop model was proposed by the valve mechanism. The accuracy of the proposed model is verified by comparing the experimental results with the simulated results.

모델 예측 제어 기법을 이용한 토크벡터링과 후륜조향 통합 제어 (Integrated Control of Torque Vectoring and Rear Wheel Steering Using Model Predictive Control)

  • 차현수;김자유;이경수
    • 자동차안전학회지
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    • 제14권4호
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    • pp.53-59
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    • 2022
  • This paper describes an integrated control of torque vectoring and rear wheel steering using model predictive control. The control objective is to minimize the yaw rate and body side slip angle errors with chattering alleviation. The proposed model predictive controller is devised using a linear parameter-varying (LPV) vehicle model with real time estimation of the varying model parameters. The proposed controller has been investigated via computer simulations. In the simulation results, the performance of the proposed controller has been compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the lateral stability and handling performance.

Ensemble UNet 3+ for Medical Image Segmentation

  • JongJin, Park
    • International Journal of Internet, Broadcasting and Communication
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    • 제15권1호
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    • pp.269-274
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    • 2023
  • In this paper, we proposed a new UNet 3+ model for medical image segmentation. The proposed ensemble(E) UNet 3+ model consists of UNet 3+s of varying depths into one unified architecture. UNet 3+s of varying depths have same encoder, but have their own decoders. They can bridge semantic gap between encoder and decoder nodes of UNet 3+. Deep supervision was used for learning on a total of 8 nodes of the E-UNet 3+ to improve performance. The proposed E-UNet 3+ model shows better segmentation results than those of the UNet 3+. As a result of the simulation, the E-UNet 3+ model using deep supervision was the best with loss function values of 0.8904 and 0.8562 for training and validation data. For the test data, the UNet 3+ model using deep supervision was the best with a value of 0.7406. Qualitative comparison of the simulation results shows the results of the proposed model are better than those of existing UNet 3+.

Response analysis of soil deposit considering both frequency and strain amplitude dependencies using nonlinear causal hysteretic damping model

  • Nakamura, Naohiro
    • Earthquakes and Structures
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    • 제4권2호
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    • pp.181-202
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    • 2013
  • It is well known that the properties of the soil deposits, especially the damping, depend on both frequency and strain amplitude. Therefore it is important to consider both dependencies to calculate the soil response against earthquakes in order to estimate input motions to buildings. However, it has been difficult to calculate the seismic response of the soil considering both dependencies directly. The author has studied the time domain evaluation of the frequency dependent dynamic stiffness, and proposed a simple hysteretic damping model that satisfies the causality condition. In this paper, this model was applied to nonlinear analyses considering the effects of the strain amplitude dependency of the soil. The basic characteristics of the proposed method were studied using a two layered soil model. The response behavior was compared with the conventional model e.g. the Ramberg-Osgood model and the SHAKE model. The characteristics of the proposed model were studied with regard to the effects of element divisions and the frequency dependency that is a key feature of the model. The efficiency of the model was confirmed by these studies.