• Title/Summary/Keyword: flow simulator

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A Study on Development of a Cognitive Process Simulator Based on Model Human Processor (모델휴먼프로세서를 활용한 인지과정 시뮬레이터 구축에 관한 연구)

  • 이동하;나윤균
    • Journal of the Korean Society of Safety
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    • v.13 no.4
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    • pp.230-239
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    • 1998
  • Though limited, Model Human Processor (MHP) has been used to explain the complex users' behaviors during human-computer interactions in a simplified manner. MHP consists of perceptual, cognitive and motor systems, each with processors and memories interacting with each other in serial or parallel mode. The important parameters of memory include the storage capacity, the decay time, and the code type of a memorized item. The important parameter of a processor is the cycle time. Using these features of the model, this study developed a computerized cognitive process simulator to predict the cognitive process time of a class match task process. An experimental validity test result showed that the mean prediction time for cognitive process of the class match task simulated 50 times by the simulator was consistent with the mean cognitive process time of the same task performed by 37 subjects. Animation of the data flow during the class match task simulation will help understand the invisible human cognitive process.

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Simulation of Miniaturized n-MOSFET based Non-Isothermal Non-Equilibrium Transport Model (디바이스 시뮬레이션 기술을 이용한 미세 n-MOSFET의 비등온 비형형장에 있어서의 특성해석)

  • Choi, Won-Cheol
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.3
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    • pp.329-337
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    • 2001
  • This simulator is developed for the analysis of a MOSFET based on Thermally Coupled Energy Transport Model(TCETM). The simulator has the ability to calculate not only stationary characteristics but also non - stationary characteristics of a MOSFET. It solves basic semiconductor devices equations including Possion equation, current continuity equations for electrons and holes, energy balance equation for electrons and heat flow equation, using finite difference method. The conventional semiconductor device simulation technique, based on the Drift-Diffusion Model (DDM), neglects the thermal and other energy-related properties of a miniaturized device. I, therefore, developed a simulator based on the Thermally Coupled Energy Transport Model (TCETM) which treats not only steady-state but also transient phenomena of such a small-size MOSFET. In particular, the present paper investigates the breakdown characteristics in transient conditions. As a result, we found that the breakdown voltage has been largely underestimated by the DDM in transient conditions.

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Dynamic Characteristics of Digital Distance Relay Scheme Using Real Time Digital Simulator(RTDS) (RTDS를 이용한 Digital 거리계전기의 동특성 시험에 관한 연구)

  • Jung, Chang-Ho;Kim, Il-Dong;Kim, Yeong-Han;Kim, Sok-Il
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.109-111
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    • 1996
  • This paper describes real time dynamic tests on the digital distance relay using new digital test system including RTDS(Real Time Digital Simulator) in KEPRI. The RTDS is developed by the Manitoba HVDC Reserch Centre and consists of specialized hardware and software which allows transients simulation of electrical power systems in real time. From high impedance fault test, it is known that the characteritics of distance reach is influenced by load flow. A detailed discussion of relay test using the RTDS simulator, high impedance faults and test results are included in the paper.

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Simulation of generable muddy water quantity and pollutant loads in sloping field using artificial rainfall simulator (실내인공강우기를 이용한 경사지 밭의 토양유실량과 오염부하 모의)

  • Shin, Min-Hwan;Choi, Yong-Hun;Seo, Ji-Yeon;Lee, Jae-Woon;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.986-990
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    • 2009
  • Using artificial rainfall simulator, the soil loss, which is deemed as most cause of muddy water problem among Non-point source(NPS) pollutant, was studied by the analysis of direct runoff flow, groundwater runoff, and groundwater storage properties concerned with rainfall intensity, slope of area, and land cover. The direct runoff showed increasing tendency in both straw covered and bared boxes which are 5%, 10%, and 20% sloped respectively. Also the direct runoff volume from straw covered surface boxes were much lower than bared surface boxes. It's deemed as that the infiltration capacity of straw covered surface boxes were increased, because the surface sealing by fine material of soil surface didn't occurred due to the straw covering. Under the same rainfall intensity and slope condition, 2.4 ${\sim}$ 8.2 times of sediment yield were occurred from bared surface boxes more than straw covered surface boxes. The volume of infiltrated were increased due to straw cover, the direct runoff flow were decreased with decreasing of tractive force in surface. To understand of relationship the rate of direct runoff flow, groundwater runoff, and groundwater storage by the rainfall intensity, slope, and land cover, the statistical test was performed. It shows good relationship between most of factors, expect between the rate of groundwater storage and rainfall intensity.

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Design of Intelligent Servocontroller for Proportional Flow Control Solenoid Valve with Large Capacity (지능형 대용량 비례유량제어밸브 서보컨트롤러 설계)

  • Jung, G.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.8 no.3
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    • pp.1-7
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    • 2011
  • As the technologies of electronic device have advanced these days, most of mechanical systems are designed with electronic control unit to take advantage of control parameter adaption to operating conditions and firmware flexibilities as well. On-board diagnosis, which detects the system malfunction and identifies potential source of error with its own diagnostic criteria, and fail-safe that can switch the mode of operation in view of recognized error characteristics enables easy maintenance and troubleshooting as well as system protection. This paper dealt with the development of diagnosis and fail-safe function for proportional flow control valve. All type of errors related to valve control system components are investigated and assigned to a specific hexadecimal codes. Cumulative error detection algorithm is applied in order for the sensitivity and reliability to be appropriate. Embedded simulator which runs simultaneously with system program provides the virtual error simulation environment for expeditious development of error detection algorithm. The diagnosis function was verified both with solenoid valve and embedded simulator test and it will enhance the valve control system monitoring function.

Experiment and Performance Prediction on Inherent Flow Coefficient of a Solenoid Valve (솔레노이드 밸브의 고유유량계수에 대한 실험과 성능예측)

  • Lee, Joong-Youp;Lee, Soo-Yong
    • Aerospace Engineering and Technology
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    • v.10 no.1
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    • pp.70-78
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    • 2011
  • The Equations of inherent flow coefficient are different from compressible to incompressible flow. The paper has been conducted to measure the inherent flow coefficient of solenoid valve under various flows. Experimental results for compressible and incompressible flow were confirmed to inherent flow coefficient correctly. The value of inherent flow coefficient for the 0.5" solenoid valve is about 2. Dynamic characteristics of a solenoid valve, which plays an important role in real model, have been analysed by AMESim simulator modeling.

Characteristics of Air Egress Velocity in Vestibule Pressurization System Using the Fire Dynamics Simulator (FDS를 이용한 특별피난계단 부속실 제연설비의 방연풍속 기류특성)

  • Ryu, Sung-Ho;Lee, Su-Kyung;Hong, Dae-Hwa;Choi, Keum-Ran
    • Fire Science and Engineering
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    • v.24 no.6
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    • pp.153-159
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    • 2010
  • In this study, we confirmed the fact that air egress velocity of pressure differential system installed at vestibule of smokeproof stairway in domestic high-rise building becomes back-flow to stair-lobby at upper vestibule. Rather it do not back-flow to the livingroom. when fire occur and the door opens to escape from fire zone. so we carry out actual and computational fluid dynamics measurement. In the case upward 45 gradient of supply damper's blade, The simulation results that air flow of upper vestible is steady but back-flow phenomenon occurred at the bottom. However, in the case of $4m^2$, direction of the flow was ideal to living room. If a vestibule’s area is smaller, it must be designed and built according to performance-based design.

A Case Study for Reasonable Emission Regulation of Odor Exhaust Stack (악취 배출구의 합리적인 배출규제를 위한 사례연구)

  • Park, Jeong-Ho;Lee, Hyung-Chun
    • Journal of Environmental Science International
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    • v.25 no.1
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    • pp.155-161
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    • 2016
  • In this study, field experiment, odor simulator, and dispersion modeling were used to evaluate the odor impact from J sewage sludge treatment facility. The height and flow rate of exhaust stack at this facility were 22.3 m and $100Nm^3/min$. The mean odor concentrations of the wet scrubber inlet and exhaust stack were $267{\pm}160$ and $93{\pm}44OU/m^3$, respectively. The odor removal efficiency of wet scrubber showed 65%. The odor simulator is used for the regulated standard calculation of the exhaust pipe(stack). Resulting odor emission rate(OER) by odor simulator was $2.4{\times}10^6(24,000OU/m^3)$. The forecasting result by Screen3 modeling showed that odor exhaust concentration up to $30,000OU/m^3$ was't exceeded maximum allowable emission level on site boundary($15OU/m^3$).

Development of the Gas Charging Simulator for Reaction Control System of KSLV-I (KSLV-I RCS 충전모사 시스템 개발)

  • Jeon, Sang-Woon;Jung, Seul;Kim, Ji-Hun
    • Aerospace Engineering and Technology
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    • v.8 no.2
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    • pp.122-126
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    • 2009
  • KSLV(Korea Space Launch Vehicle)-I is designed as a launch vehicle to enter a 100 kg-class satellite to the LEO(Low-Earth Orbit). Attitude angles of the upper-stage, including roll, pitch and yaw are controlled by cold gas thruster system using nitrogen gas. To verify the flow rate of the gas charging system and to prepare a nitrogen gas charging scenario, the development of a gas charging simulator for RCS(Reaction Control System) is required. This paper describes the orifice design, development, and test of the gas charging simulator for RCS of KSLV-I.

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Implementation of Automation System for the Fluid Analysis of Axial Fan Using Supercomputer (슈퍼컴퓨터 활용 축류팬 유동해석 자동화 시스템 개발)

  • Kim, Myung-Il;Lee, Seung-Min;Lee, Sang-Min
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.288-291
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    • 2008
  • Recently, the importance and necessity of engineering analysis has shown a steady growth. However, researchers working in small and medium enterprises know little about the usefulness of engineering analysis and suffer from lack of technical knowledge. Axial fan is air fluid machinery in various fields of industry such as automobile, electric appliance, and heavy machinery. It is also a time and budget consuming equipment to develop the axial fan through physical experiments. In order to overcome this problem, we have designed and developed a web-base automated simulator for axial fan's fluid analysis using supercomputer. Automated simulator means that all of processes for engineering analysis including pre-process, solving, and post-process can be performed automatically without user intervention after transferring fan model(CAD files) made by user. After executing the simulator with some parameters, user can receive the report including pressure P and flow rate Q. In this paper, we introduce the architecture of our easy and efficient automated engineering analysis simulator, related techniques and result of development.

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