• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.83-84
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• 2013

최근 다양한 시스템의 상태를 추정하는데 시스템의 운동 특성을 모델링하는 기법이 많이 연구되고 있다. 이 기법은 시스템의 운동 특성을 수학적으로 모델링하는 것으로 모델링의 정확도에 따라 시스템의 상태 추정 정확도에 많은 영향을 미치게 된다. 따라서 본 논문에서는 표적의 기동 특성을 모델링하고 표적의 현재와 과거의 상태를 이용하여 정의된 기동 모델 중 적합성을 판단하는 기법을 제시하며 시뮬레이션을 통하여 기동하는 표적의 모델을 정확하게 판단하는지를 검증하고자 한다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.2
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• pp.187-193
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• 2009

Dynamic response of an elastic pendulum system under random excitations was studied by using the Lagrangian equations of motion which uses the kinetic and potential energy of a target system. The responses of random excitations were calculated by using Monte Carl simulation which uses the series of random numbers. The procedure of Monte Carlo simulation is generation of random numbers, system model, system output, and statistical management of output. When the levels of random excitations were changed, the expected responses of the pendulum system showed various responses.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.1-7
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• 2015

Korea's electricity supply and demand policy has focusing on electricity demand side management instead of the expanding supply and a lot of effort for LED(Light Emitting Diode) at the time. This paper calculated the optimal subsidy for LED spread. For this purpose, it analyzed the impact on spread of the lighting appliances each subsidy level from BDM(Bass Diffusion Model) and predicted the number of lighting appliances according to subsidy level in the future. The case study is calculated susidy for satisfaction of LED target using the suggested model in the future and verified availability.

• Journal of Industrial Technology
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• v.18
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• pp.241-248
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• 1998

In this study, a modeling method of power-assisted steering systems and driver models for vehicle dynamic analysis using AUTODYN7 is presented. Pressure-flow relations of flow control valve are derived, and the equations of motion of a steering gear are obtained. Combining pressure-flow relations and equations of motion, the steering force can be represented as a function of steering wheel angle or torque. Driver model was modeled based on a PID controller and forward target method. With the steering systems and driver model, various driving tests are conducted using AUTODYN7.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.540-545
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• 2008

The design on balance shaft module is performed based on the target specification of engine module as well as the its own dynamic nature under a high speed rotation. However, the specific information for engine module is not always available for non-motor companies even though a reliable analytical result should be attached in the conceptual design process or more detail works. In this paper, the analysis on balance shaft module, both each parts or module itself, is suggested to estimate the performance on the target component with respect to durability and NVH without any consideration of a engine module. This methodology could modify the nominal balance shaft model before the production of prototype such that cost reduction as well as time saving can be expected during design process of balance shaft module.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.4
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• pp.23-31
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• 2010

As the analysis and design technologies for electro-magnetic actuation has advanced over the years, proportional solenoid valve is gaining acceptance in wide range of industrial and commercial applications because of its superior characteristics over the conventional AOV or MOV, such as improved performance, reduced maintenance costs. This research deals with the position controller design of two-stage flow control solenoid valve. Investigation of steady-state characteristics and dynamic model identification for pilot disc is performed. Least square method to minimize the error magnitude of frequency response between the closed-loop and target system is applied to the design of PI-controller gains. From the experiments of step and frequency response, it is concluded that the controller meets the performance specification of target system, which verifies the usefulness of controller design method for proportional solenoid valve.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.5
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• pp.35-41
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• 1998

This paper presents a decoupling controller of the missile seeker scan loop with a spin-stabilized platform. A precise seeker motion with respect to the scan command is essential for the higher acquisition probability of the target. As the seeker scan loop is a deeply cross-coupled two input two output system, an accurate pointing or scanning for each axis to the target is very difficult, even though provided with the help of a high performance controller. When a decoupling control is applied to the seeker scan loop, the cross-coupling between two axes can be reduced to a remarkable amount. As a low order of controller is required for the real time operation, a PI controller with decoupling filter is suggested and compared with other controllers. A linearized dynamic model of seeker scan loop is used and validated through the comparison of experimental results of step responses.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.389-394
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• 2017

In this paper, the captive model test of a submarine using the RA test was carried out in a square basin. The target model submarine consisted of four types varying according to the position of conning tower and control planes. Hydrodynamic derivatives were acquired by multi-regression analysis. As a result, horizontal dynamic stability indexes of the four types presented positive values and satisfied dynamic stability requirements. In addition, the stability index of type 1 and type 4 - each with the same cruciform configuration of the aft planes - scored within the acceptable range of motion stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.1-6
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• 2011

The accurate results of finite element analysis are directly related to reliability FE model which is exactly describing dynamic characteristics of target structure. So, a model updating is necessary to establish reliable FE(Finite Element) model with a lot of experience and effort using modal testing. A large structure is too difficult to obtain the dynamic characteristics owing to its weight and size. In this work, using main gun firing test, modal testing was performed to obtain dynamic characteristics of large naval vessel, which is difficult to tap the general modal testing method. The result of experiment was considered its possibility and future plans.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.147-154
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• 2019

The finite element model updating can be defined as the problem of finding the parameters of the finite element model which gives the closest response to the actual response of the structure by measurement. In the previous researches, optimization based methods have been developed to minimize the error of the response of the actual structure and the analytical model. In this study, we propose an inverse eigenvalue problem that can directly obtain the parameters of the finite element model from the target mode information. Deep Neural Networks are constructed to solve the inverse eigenvalue problem quickly and accurately. As an application example of the developed method, the dynamic finite element model update of a suspension bridge is presented in which the deep neural network simulating the inverse eigenvalue function is utilized. The analysis results show that the proposed method can find the finite element model parameters corresponding to the target modes with very high accuracy.