• Title/Summary/Keyword: Computer simulation experiment

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Design of a Digital Adaptive Flight Control Law for the ALFLEX

  • Ito, Hideya;Shimada, Yuzo;Uchiyama, Kenji
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.519-524
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    • 2003
  • In this report, a longitudinal adaptive flight control law is presented for the automatic landing system of a Japanese automatic landing flight experiment vehicle (ALFLEX). The longitudinal adaptive flight control law is designed to track an output of the vehicle to a guidance signal from the guidance portion of the automatic landing system. The proposed adaptive control law in the attitude control portion adjusts the controller gains continuously online as flight conditions change, in spite of the existence of unmodeled dynamics. The number of the controller gains to be adjusted is decreased to 1/2 from the previous studies. Computer simulation involving six-degree-of-freedom (DOF) nonlinear flight dynamics is performed to examine the effectiveness of the proposed adaptive control law. In order to verify the influence of the dispersion of the initial conditions, the Monte Carlo simulation is also applied. The initial conditions are more widely dispersed than the previous studies. As a result, except under the unsuitable initial conditions, the ALFLEX successfully landed on the runway.

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A study on implementation of courseware for Digital System Simulation and Crcuit Synthesis (디지털 시스템의 시뮬레이션과 회로합성을 위한 코스웨어 구현에 관한 연구)

  • 이천우;김형배;강호성;박인정
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.3
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    • pp.94-100
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    • 1999
  • In this paper, we are implemented the courseware targets to the integrated a digital system analysis, a design theory, and a hardware description language training and a logic analysis. This paper consists of two subjects. One is that the learning of a digital system analysis, that of a design theory, and the training of a hardware description language is simultaneously performed. The other is that the experiment of courseware. To learn the hardware description language, the explanation using sound or moving images, setting-up of a simulation or a synthesis program, and simulating are executed on a courseware. And also, we proposed an integrated systems for the hardware description language and a logic synthesis. Also, The reliablity of the tool was verified to be preyed an efficient operation of an implemented digital system courseware tool by korea computer research association.

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A Study on the Characteristics of All-Optic Tunable Filter in various temperature and strain Using Fiber Bragg Grating (FBG를 이용한 온도 및 스트레인의 영향에 따른 전광필터 특성에 관한 연구)

  • Jang Woo-Soon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.11
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    • pp.17-22
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    • 2005
  • In this study, we suggested wave-variable Bragg lattice using the characteristic of the Bragg wave that varies according to the change of the temperature imposed on the optical fiber lattice device, and experimented using a simulation test. We analyzed the results of the FBG change according to the change of the temperature obtained in the variable FEG computer simulation and experiment to suggest optimal data. Therefore, utilizing wave-variable optical filter through FBG allows us to combine other channels beyond optical fiber lattice device wave, and can be used as a helpful device in the Dense Wavelength Division Multiplexed system with a channel intervention of 0.08nm(10GHz).

Analysis of Cavity Pressure and Dimension of Molded Part According to V/P Switchover Position in Injection Molding

  • Cho, Jung Hwan;Kwon, Soon Yong;Roh, Hyung Jin;Cho, Sung Hwan;Kim, Su Yeon;Lyu, Min-Young
    • Elastomers and Composites
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    • v.52 no.4
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    • pp.309-316
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    • 2017
  • In injection molding, the quality of an injection molded product varies greatly depending on the molding conditions. Many researche studies have been conducted on the quality analysis of molded parts according to the molding conditions such as injection pressure, injection temperature, and packing pressure. However, there have not been many studies on the V/P switchover timing. It is known that when a large pressure is applied to a cavity in the packing phase, the cavity pressure is most affected by the packing pressure. In addition, depending on the position (timing) of the packing pressure, it can have a direct influence on quality based on the shrinkage and dimensions of the molded parts. In this study, the change in pressure profile in the cavity according to the V/P switchover position is confirmed. A CAE analysis program (Moldflow) was used to simulate and analyze two models using the PC and PBT materials. In order to compare these results with the actual injection molding results, injection molding was performed for each V/P switchover position, and the correlation between simulation and experiment, especially for the shrinkage of molded parts, was evaluated.

Stealthy Behavior Simulations Based on Cognitive Data (인지 데이터 기반의 스텔스 행동 시뮬레이션)

  • Choi, Taeyeong;Na, Hyeon-Suk
    • Journal of Korea Game Society
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    • v.16 no.2
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    • pp.27-40
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    • 2016
  • Predicting stealthy behaviors plays an important role in designing stealth games. It is, however, difficult to automate this task because human players interact with dynamic environments in real time. In this paper, we present a reinforcement learning (RL) method for simulating stealthy movements in dynamic environments, in which an integrated model of Q-learning with Artificial Neural Networks (ANN) is exploited as an action classifier. Experiment results show that our simulation agent responds sensitively to dynamic situations and thus is useful for game level designer to determine various parameters for game.

A Study on the Development of the VTL Vehicle Dynamics Model to Analyze Vibration Characteristics (차량 진동특성 해석을 위한 VTL 차량 모델 개발에 관한 연구)

  • Kwon, Seong-Jin;Bae, Chul-Yong;Kim, Chan-Jung;Lee, Bong-Hyun;Koo, Byoung-Kook;Rho, Guck-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.409-414
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    • 2007
  • Nowadays, with the advancement of computational mechanics, and vehicle dynamics simulation linked up with virtual testing laboratory(VTL) and virtual proving ground(VPG) technologies has become a useful method for analyzing numerous driving performances and diverse noise/vibration characteristics. In this paper, the analytical vehicle model based on multi-body dynamics theory was developed to investigate the vibration characteristics according to various road conditions. For the purpose, the whole vehicle parameters, each vehicle's part parameter, and part connecting elements such as spring, damper, and bush were measured by an experiment. Also, the vehicle dynamics model, which includes the front suspension, rear suspension, steering, front wheel, rear wheel, and body subsystems has been constructed for computer simulation. With the developed vehicle dynamics model, three forces and three moments measured at each wheel center were applied to evaluate and analyze dynamics and vibration characteristics for miscellaneous road conditions.

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The Pattern Draft Factors Affecting the Silhouette of Gored Skirts in Virtual Clothing Simulation (가상 착의 시 고어드스커트의 패턴 제도 요인이 실루엣에 미치는 영향)

  • Choi, Soon Hee;Kim, Yeosook
    • The Korean Journal of Community Living Science
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    • v.24 no.3
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    • pp.399-409
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    • 2013
  • The purpose of this study is to compare how the number of panels, the amount of flare and the flare starting point affect the silhouette of the gored skirt. This study consisted of (1) creation of 3D body representations (2) comparison of silhouette between 3D virtual gored skirt and actual gored skirt by pilot experiment (3) pattern drafting of twenty-seven different gored skirts for 3D body representations (4) a computer simulation of twenty-seven different gored skirts for visualization and assessment (5) visual inspection of twenty-seven different 3D virtual gored skirts (6) comparison of ham shapes and measurements for the node and size analysis. A visual inspection of twenty-seven different 3D virtual gored skirts showed clear differences by the amount of flare and the flare starting point ; however, there was notably less difference in the width of ham among six-piece, eight-piece and ten-piece panels. This demonstrated that there was less influence on the number of panels than the amount of flare width of ham and extent of ham for the 3D virtual gored skirt.

Research on the Multi - purpose Nd:YAG Laser Power System using LLC Converter (LLC 공진형 컨버터를 사용한 다용도 Nd:YAG 레이저 전원장치 설계)

  • Zheng, Tao;Kim, Hee-Je;Lee, Jae-cheol;Xu, Guo-Cheng
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.6
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    • pp.885-890
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    • 2015
  • LLC resonant converter has been widely used because of its high efficiency and high energy density. In this paper, we designed a LLC resonant converter as the main power supply of the Nd:YAG pulse laser. First harmonic approximation (FHA) is used to model the LLC resonant converter. FHA equivalent circuit model and the transfer function of the LLC resonant converter is proposed. Soft start technology is also used to suppress the surge current. The laser output simulation test result is identical with the practical test, the laser energy of every pulse can reach up to 2.5J, and the pulse per second (PPS) can be adjusted from 6 to 18. The power system is verified stable and reliable by both of the simulation and experiment results.

Verification Experiment and Analysis for 6kW Solar Water Heating System(Part 3 : Optimum Design and Economic Evaluation) (6kW급 태양열 온수급탕 시스템의 실증실험 및 분석(제3보 최적설계 및 경제성평가))

  • Choi Bong Su;Lee Bong Jin;Kang Chaedong;Hong Hiki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.1
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    • pp.16-24
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    • 2005
  • The goal of the present paper is to show the optimum design and operation conditions on 6 kW solar water heating system by using computer simulation with verified modelling. As the object functions, we took not only the amount of acquired and auxiliary heat but LCC, which has a relative importance and decisive role in economy. As expected, the maximum heat is acquired at the slope of collector with the equal degree to the latitude, facing the south. The capacity increase of the circulation pump and the storage tank lead to the increase of acquired heat and the decrease of auxiliary heat, but do not necessarily give economical advantages owing to additional electrical power consumption. In the present system, the minimum LCC can be obtained at the storage tank volume of 450 L and the mass flow rate of 0.344 kg/s.

Dynamic characteristic identification of PWM solenoid valve for automatic transmission (자동변속기용 펄스폭변조 솔레노이드 밸브의 동특성 식별)

  • Jung, Gyu-Hong;Cho, Baek-Hyun;Lee, Kyo-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.10
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    • pp.1636-1647
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    • 1997
  • As most of today's automatic transmissions in passenger car adopt a electro-hydraulic control system, the role of electronically controlled solenoid valves occupies an important position and it is essential to predict solenoid transient characteristics in order to design and evaluate the performance of the hydraulic control system. However, in general, both the magnetic and electrical parameters f the solenoid system are hardly known and it is not easy to model this section with moderate complexity although mechanical system could be developed using the classical second order system. This paper presents a dynamic modelling technique of a solenoid valve, that is controlled by pulse width modulation for an automatic transmission, in terms of system identification theory. In nonlinear computer simulation, it is shown that the identified systems which produce magnetic force to input duty cycle for various excitation signals predict the static and dynamic performance very well near the operating point and in experiment conducted to confirm the validity of identification theory for PWM solenoid valve, we find that there is a good agreement between the experimental data and simulation result. Hence, this model can be utilized in the development of pressure control system with PWM solenoid valve.