• Title/Summary/Keyword: Phenomenon Modeling

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Verification of Underground Distribution Line Modeling with Field Test (실증시험을 통한 지중배전선로 모델링 기법 검증 연구)

  • Yun, Chang-Sub;Lee, Jae-Bong;Kim, Byong-Suk;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.12
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    • pp.2091-2097
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    • 2007
  • This paper described the verification of modeling technique of underground distribution from comparison between field test and simulation. It needs more exact transient phenomenon analysis model to establish lightning protection of underground distribution line. Although, there were a lot of transient phenomenon researches, nobody could has verified the confidence of modeling from field tests in interior until now. So, simulation model verified field test is needed to analyse transient phenomenon of underground distribution system. The examination must be accomplished in many different condition before suggesting these verified analysis model. In this paper, the conditions were examined and the various data results on the different line composition was compared with the EMTP simulation, when the lightning impulse test was accomplished at underground distribution line. Also the value between field test and simulation was very closed and the method of modeling has demonstrated confidence, when the method is used to analyse domestic transient phenomenon of underground distribution.

3-D Numerical Prediction Modeling of Air Pollution in Coastal Urban Region -(I) An Effect Prediction for Deposition Phenomenon affecting on Air Quality (연안도시지역에서 대기오염의 3차원 수치예측모델링 -(I) 침적현상이 대기질에 미치는 영향예측)

  • 원경미;이화운
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.5
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    • pp.625-638
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    • 1999
  • Air quality modeling for coastal urban region has been composed of a complex system including meteorological, chemical and physical processes and emission characteristics in complex terrain. In this study, we studied about an effect prediction for deposition phenomenon affecting on air quality in Pusan metopolitan metropolitan city. In air quality modeling including ship sources, a situation considered deposition process habe better result than not considered when compared with observed value. Air pollutants emitted into urban air during the daytime nearly removed through urban atmosphere polluted. Also these phenomena correlated concentration variation connent with sea/land breezes and terrain effect. Therefore we conclude that the concentration was low at daytime when deposition flux is high, and deposition effect on industrial complex and Dongrae region is considerable in particular.

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Investigation of the Knocking Phenomenon in SI Engines (가솔린 엔진에서의 노킹 현상 해석)

  • Min, Kyoung-Doug
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.17-23
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    • 2000
  • Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

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Real-time Modeling and Rendering of Tidal in Qiantang Estuary

  • Wang, Chang-Bo
    • International Journal of CAD/CAM
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    • v.9 no.1
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    • pp.79-83
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    • 2010
  • Tidal bore is a peculiar nature phenomenon which is caused by the lunar and solar gravitation. Based on the physical characters of tidal bores, in this paper we propose a novel method to model and render this phenomenon, especially the tidal waves in Qiantang estuary. According to Boltzmann equation for tidal waves, we solve it with the novel triangle mesh of Kinectic Flux Vector Splitting (KFVS) mode. Then a method combining a curve forecasting wave and particles model is proposed to render the dynamic scenes of overturning tidal waves. Finally, with some rendering technologies, various realistic tidal waves under diversified conditions is rendered in real time.

Investigation of the Knocking Phenomenon in SI Engines (가솔린 엔진에서의 노킹 현상 해석)

  • Min, Kyoung-Doug
    • Journal of the Korean Society of Combustion
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    • v.5 no.2
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    • pp.29-35
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    • 2000
  • Knock in SI engines causes physical damage to the piston and combustion chamber and lowers the thermal efficiency. The increase in compression ratio which can improve the thermal efficiency and engine performance has been limited by engine knock. So the need of making clear the knocking phenomenon has increased. This paper reviews the methods of knock detection, characterization and prediction of knock with the reduced chemical kinetic modeling.

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Enhanced Equivalent Circuit Modeling for Li-ion Battery Using Recursive Parameter Correction

  • Ko, Sung-Tae;Ahn, Jung-Hoon;Lee, Byoung Kuk
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1147-1155
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    • 2018
  • This paper presents an improved method to determine the internal parameters for improving accuracy of a lithium ion battery equivalent circuit model. Conventional methods for the parameter estimation directly using the curve fitting results generate the phenomenon to be incorrect due to the influence of the internal capacitive impedance. To solve this phenomenon, simple correction procedure with transient state analysis is proposed and added to the parameter estimation method. Furthermore, conventional dynamic equation for correction is enhanced with advanced RC impedance dynamic equation so that the proposed modeling results describe the battery dynamic characteristics more exactly. The improved accuracy of the battery model by the proposed modeling method is verified by single cell experiments compared to the other type of models.

Modeling and Evaluation of Slip-Mode Frequency Shift Method for Anti-islanding Method (슬립모드 방식을 이용한 단독운전 검출기법의 모델링과 평가)

  • Yu, Byung-Gyu;Jung, Young-Seok;So, Jung-Hun;Yu, Gwon-Jong
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.520-522
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    • 2005
  • Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and power supply facilities as a result of unsynchronized reclosure. In order to prevent this phenomenon, various anti-islanding methods have been studied. Even though the slip mode frequency shift (SMS) method has been regarded as a highly effective anti-islanding method, the analytical design method of that was not cleared. This paper proposes a modeling of the SMS method using non-detection zone (NDZ) and evaluation of the method according to the test conditions of IEEE Std. 929-2000. The SMS method is derived analytically through the modeling and verified visually by simulation and experiment.

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Analysis and Modeling of Slip Mode Frequency Shift Method for Anti-islanding (슬립모드 주파수변이 방식의 단독운전 검출법의 분석과 모델링)

  • Yu, Byung-Gyu;Jung, Young-Seok;So, Jung-Hun;Yu, Gwon-Jong
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1699-1701
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    • 2005
  • Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and rower supply facilities as a result of unsynchronized reclosure. In order to prevent this phenomenon, various anti-islanding methods have been studied. Even though the slip mode frequency shift(SMS) method has been regarded as a highly effective anti-islanding method, the analytical design method of that was not cleared. This paper proposes a modeling of the SMS method using non-detection tone(NDZ) and evaluation of the method according to the test conditions of IEEE Std. 929-2000. The SMS method is derived analytically through modeling and verified visually by simulation and experiment.

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Rusty Images Applied Fashion Design - For Digital Textile Printing Method - (녹 이미지를 응용한 의상디자인 - 디지털 텍스타일 프린팅 기법을 중심으로 -)

  • Yoon, Ji-Ill;Lee, Youn-Hee
    • The Research Journal of the Costume Culture
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    • v.18 no.5
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    • pp.1003-1016
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    • 2010
  • The purpose of this study is to reorganize any rusty image including natural modeling characteristic presented from the natural phenomenon to certain patterns in order to create the fashion design that are valued in the expansion of independently expressional area and modeling art. As a method for research, the author analyzed the concept and characteristic for rust with a base of theoretical background by the documental research and realistic consideration, analyzed its modeling characteristic through domestic and overseas pictures, and e-documents as data, inspected the modeling activities of various categories that various images were adapted related to rust, looked into the concept of Digital Textile Printing and its producing procedure as an expressional method, and analyzed the examples of modern dress and its ornament making use of Digital Textile Printing. The conclusions of this study are as below. First, the rust occurred due to the natural phenomenon is the bond with different material like metal, each unique modeling characteristic occurs and harmony of various patterns has abundant aesthetic value. Second, the author could endowed sensible characteristic and speciality with works and could produce creative fashion design that painting, abstractive pattern and harmony of unique sense of colors are significant by using the image of rust, Third, to emphasize natural feeling of rust, the author could develop creative design that simple silhouette and impressive pattern look significant by reorganizing and applying rust according to repetition, increment, rhythm, contract, emphasis and harmony. Fourth, Digital Textile Printing method is used to induce visual effect by the expression of feels of rust, and the author could express the natural patterns, delicate expression for the feels of a material and unique design of emotion.

The pressure distribution on the rectangular and trapezoidal storage tanks' perimeters due to liquid sloshing phenomenon

  • Saghi, Hassan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.2
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    • pp.153-168
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    • 2016
  • Sloshing phenomenon is a complicated free surface flow problem that increases the dynamic pressure on the sidewalls and the bottom of the storage tanks. When the storage tanks are partially filled, it is essential to be able to evaluate the fluid dynamic loads on the tank's perimeter. In this paper, a numerical code was developed to determine the pressure distribution on the rectangular and trapezoidal storage tanks' perimeters due to liquid sloshing phenomenon. Assuming the fluid to be inviscid, the Laplace equation and the nonlinear free surface boundary conditions were solved using coupled boundary element - finite element method. The code performance for sloshing modeling was validated using Nakayama and Washizu's results. Finally, this code was used for partially filled rectangular and trapezoidal storage tanks and free surface displacement, pressure distribution and horizontal and vertical forces exerted on the tanks' perimeters due to liquid sloshing phenomenon were estimated and discussed.