• 조명전기설비학회논문지
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• 제29권2호
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• pp.40-46
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• 2015

This paper presents a method of controlling a three-phase VSI (Voltage Source Inverter) using MPC (Model Predictive Control) designed using Laguerre functions. It also provides a model of the three-phase VSI and its resistive-inductive load and then an overview of MPC design using Laguerre functions. The biggest challenge in using MPC is the high number of computations involved, which makes online implementation difficult. On the other hand, the LMPC (Laguerre Model Predictive Control) reduces the number of computations made and so online implementation becomes possible where traditional MPC would be unteneble. The simulation results from MATLAB are also provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.179-181
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• 1998

In this paper, one chip PWM pattern generator which eliminates time delay of computations and improves utilization factor of voltage is proposed. Both amplitude of sinusoidal signal and triangular signal are directly controlled. Thus, time delay of computations can be eliminated, and it is possible to track accurately instantaneous current for a sudden change of load with microprocessor 80C196KC. In addition, setting dead-time is also possible for wide range. From experimental work with inverter system for driving induction motor, the validity of proposed one chip PWM pattern generator is verified.

• 멤브레인
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• 제4권2호
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• pp.96-105
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• 1994

이 논문은 거대전하고분자의 막전달 현상을 위한 이론적 모델을 연구하는데 있다. 전기적 힘에 의한 전하고분자 물질의 형상은 빠르게 곧게 뻗으면서 진행되며, 곧게 뻗는 시간과 길이는 막 전달의 동적현상을 이해하는데 도움을 주고 있다. 빠르게 곧게 뻗을 때, 전하고분자의 두 끝이 전기힘 방향으로 동시에 끌리는 현상이 일어난다. 이같은 형식의 이해는 거대전하고분자의 막분리를 이해하는데 도움을 주고 있다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 춘계학술발표대회
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• pp.121-124
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• 2015

Recent global and cloud computing render the Internet and Web application to be a paramount field since it is uncomplicated to access and less time and space limitation. On the other hand, a growing number of computations using grid computing techniques indicates the requirements and quantities of large-scale computations are becoming foremost progressively. Therefore, that will be much practicable if there is a Web-based service that could provide Grid computing functions. In this paper, Several similar Web-based cloud and parallel computing systems will be discussed and a model of Web application termed GCaaS which supports grid computing services will be introduced.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.187-195
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• 2012

본 연구에서는 터보펌프 인듀서 주변의 극저온 유동장에 대한 수치해석을 주로 다룬다. 이를 위해 수치해석에 사용된 수치기법에 대한 내용을 우선 다룬다. 수치기법에 대한 검증 문제로 2차원/축대칭 극저온 유동문제를 해석하였고 이 과정에서 다양한 공동모델에 대한 비교 연구를 수행하였다. 마지막으로 3차원 터보펌프 인듀서에 대한 수치해석을 수행하고, 실험 결과와 타 연구결과와 비교함과 동시에 극저온 유체에서 나타나는 공동현상의 특징을 살펴보았다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3401-3420
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• 2021

We provide a traceable ciphertext-policy attribute based encryption (CP-ABE) construction for monotone access structures (MAS) based on composite order bilinear groups, which is secure adaptively under the standard model. We construct this scheme by making use of an "encoding technique" which represents the MAS by their minimal sets to encrypt the messages. To date, for all traceable CP-ABE schemes, their encryption costs grow linearly with the MAS size, the decryption costs grow linearly with the qualified rows in the span programs. However, in our traceable CP-ABE, the ciphertext is linear with the minimal sets, and decryption needs merely three bilinear pairing computations and two exponent computations, which improves the efficiency extremely and has constant decryption. At last, the detailed security and traceability proof is given.

• Quantitative Bio-Science
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• 제37권2호
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• pp.73-79
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• 2018

As high frequency (HF, for short) time series is now prevalent in the presence of real time big data, volatility computations based on traditional ARCH/GARCH models need to be further developed to suit the high frequency characteristics. This article reviews realized volatilities (RV) and multivariate GARCH (MGARCH) to deal with high frequency volatility computations. As a (functional) infinite dimensional models, the fARCH and fGARCH are introduced to accommodate ultra high frequency (UHF) volatilities. The fARCH and fGARCH models are developed in the recent literature by Hormann et al. [1] and Aue et al. [2], respectively, and our discussions are mainly based on these two key articles. Real data applications to domestic UHF financial time series are illustrated.

• 대한조선학회지
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• 제13권2호
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• pp.13-43
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• 1976

A potential flow approach is used to develop a method and an associated computer program for floating marine structures of general configuration in wave of all water depths with arbitrary heading. It computes the total force distributions and six degrees-of-freedom motion. The hydrodynamic-force equations and derived become identical under certain assumptions to the equations commonly used by the offshore industry, and the two methods are compared in detail. The computed motions of all six degree agree quite well with model-scale and full-scale experimental data for two typical semisubmersible drilling rigs in finite-depth water. Also the presented motion computations are more accurate than a previous work by the second approach. The present computations use experimentally validated or determined values of frequency-dependent hydrodynamic coefficients with the effects of the free surface and both finite and infinite water depths. The present method generates sufficient computation accuracy to use for practical design applications.

• 대한수학회보
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• 제60권4호
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• pp.985-1001
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• 2023

Recently, Alzer and Choi [2] introduced and studied a set of the four linear Euler sums with parameters. These sums are parametric extensions of Flajolet and Salvy's four kinds of linear Euler sums [9]. In this paper, by using the method of residue computations, we will establish two explicit combined formulas involving two parametric linear Euler sums S⁺⁺_p,q (a, b) and S^+-_p,q (a, b) defined by Alzer and Choi, which can be expressed in terms of a linear combinations of products of trigonometric functions, digamma functions and Hurwitz zeta functions.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.160-162
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• 2005