• The Korean Journal of Rheology
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• v.1 no.1
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• pp.46-53
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• 1989

유한요소법을 이용하여 애뉼라다이 팽창현상을 수치 해석학적으로 분석하였다. 이보 고는 계속적인 연구의 일부로써 비탄성 비뉴토니안 유체인 지수법칙형의 유체에 대한 모사 이다. 이지수법칙형의 유체는 간단하나 고분자 공정 연구에 많이 쓰이는 구성식으로써, 분석 결과는 환형압축체의 두께는 지수법칙 지수에 비례하여 증가하였다. 높은 전단응력 감소유 체의 경우 두께는 증가하지 않고 감소하였다. 비등온 유체 및 여러 다른 형태의 압출형에 대한 수치해석 결과도 예시하였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.55-57
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• 2005

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.23-26
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• 2002

전력품질 진단장치 개발을 위한 Hardware를 DSP를 이용하여 설계하였고 Software에서는 Sag, Swell, Interruption, Overvoltage, Undervoltage, Harmonic을 검출할 수 있는 알고리즘을 제시하였다. 또한 검출된 진단Data는 Network을 이용하여 원 거리에 있는 PC에서 Monitoring 함으로서 Field System의 전력분석에 효율적임을 증명하여 보였다.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.286-289
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• 2002

In this paper, we use the PI dual control using do transformation(dq stationary frame and dq synchronous rotating frame) for series voltage sag and swell compensation algorithm. Analysis, simulation results are presented for voltage sags and swells on a three-phase unbalanced voltage source.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.359-359
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• 2000

Generally, level control in the steam generator of a nuclear power plant is difficulty process control, because the low power operating can lead nonminimum phase characteristics(swell and shrink phenomenon) and flow measurement are unreliable and nonlinear characteristics. This paper presents a framework for solving this problem based on the constrained linear model predictive control and introduces the design of method for the level of the controller in the entire operating power of the steam generator, and compares with conventional PI controller.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.217-223
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• 2016

Outcome misclassification is widespread in classification problems, but methods to account for it are rarely used. In this paper, the problem of inference with misclassified multinomial logit data with a large number of multinomial parameters is addressed. We have had a significant swell of interest in the development of novel methods to infer misclassified data. One simulation study is shown regarding how seriously misclassification issue occurs if the number of categories increase. Then, using the group lasso regression, we will show how the best model should be fitted for that kind of multinomial regression problems comprehensively.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.485-487
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• 2007

본 연구에서는 Z-소스 네트워크를 갖는 순시전압sag 보상기를 제안하였다. 제안된 시스템은 연료전지 스택(fuel cells stack)을 갖고 있는 Z-소스 인버터의 shoot-through제어에 의하여 ac보상전압을 직접 발생한다. PSIM 시뮬레이션에 의하여 sag와 swell이 발생되는 정상상태와 과도상태에서의 제안된 방법의 타당성을 검토하였다.

• Membrane Journal
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• v.8 no.1
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• pp.11-21
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• 1998

The study on penetrant transport in glassy polymers has been actively pursued for decades because of its growing significance in polymer processing and related applications such as not only membranes, but corrosion protective coatings, microlithography, microelectronic fabrication, etc. In membranes application of polymeric materials, successful utilization requires understanding of how solvents penetrate, swell, and sometimes dissolve polymeric materials under various environmental conditions, as their permselecdve performance is significantly affected by it. The expose of polymer membranes to solvents may result in the structural failure due to mechanical softening, embrittlement or crazing.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.3
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• pp.117-123
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• 2016

One of the major characteristics of the swell-like high waves, which occur in the East Sea mostly in winter with large height and long period, is its suddenness associated with the rapid development of high waves from a calm state of sea. To represent such suddenness, in this study, the term sudden high waves is introduced. To propose the criterion of sudden high waves, comparisons were made between the wave measurement data at Gangneung and Wangdolcho for eight years from 2005 and the record of marine accidents and property damage on the coast of Gangwon-do Province and Gyeongsangbuk-do Province during the same period. It was found that most of the accidents occurred when ${\Delta}(H^2L)/{\Delta}t$ was approximately greater than the top 20% or $88.6m^3/hr$, which is therefore proposed as the criterion of sudden high waves. The used variable represents the rate of increase of the wave energy in one wavelength, including not only height and period but also suddenness of high waves.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.379-387
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• 2015

A custom power device provides an integrated solution to the present problems that are faced by the utilities and power distribution. In this paper, a new controller is designed which is connected to a multiconverter unified power quality conditioner (MC-UPQC) for improving the power quality issues adopted modified synchronous reference frame (MSRF) theory with Fuzzy logic control (FLC) technique. This newly designed controller is connected to a source in order to compensate voltage and current in two feeders. The expanded concept of UPQC is multi converter-UPQC; this system has a two-series voltage source inverter and one shunt voltage source inverter connected back to back. This configuration will helps mitigate any type of voltage / current fluctuations and power factor correction in power distribution network to improve power quality issues. In the proposed system the power can be conveyed from one feeder to another in order to mitigate the voltage sag, swell, interruption and transient response of the system. The control strategies of multi converter- UPQC are designed based on the modified synchronous reference frame theory with fuzzy logic controller. The fast dynamics response of dc link capacitor is achieved with the help of Fuzzy logic controller. Different types of fault conditions are taken and simulated for the analysis and the results are compared with the conventional method. The relevant simulation and compensation performance analysis of the proposed multi converter-UPQC with fuzzy logic controller is performed.