• 전기학회논문지
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• 제57권4호
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• pp.596-602
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• 2008

This paper presents the dynamic characteristic analysis of Permanent Magnet Linear Synchronous Motor(PMLSM) according to variable load. In order to analyze dynamic characteristics, finite element method(FEM) was used for calculation of the parameter and the Matlab simulink was used for dynamic characteristic simulation. The measuring system of the dynamic characteristics was manufactured and the experiment results were compared with the simulation results.

• 대한한의진단학회지
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• 제18권2호
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• pp.121-136
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• 2014

Objectives For the excellent differentiation of syndromes, we study on the individual characteristic factor by the inspection of body shape. Methods To the subject of diagnosis special books and diagnostics textbook of korean medicine, we arrange the individual characteristic factor by the four methods of diagnosis. Results The individual characteristic factor analyzed by the inspection of the body shape in the "Huangdineijing 黃帝內經" and "Donguisusebowon 東醫壽世保元" was observed stereotyped. The inspection of the body shape means to diagnose the patient by examining the individual physical conditions of the patient. The body depends on visceral essence to nourish, while the functions of the viscera and the conditions of visceral essence may be reflected by the body. The inspection of individual physical strength and weakness may enable one to know the functions of the viscera and the conditions of ki(氣) and blood. And also the inspection of local regions is used to closely examine some regional areas to obtain necessary clinical data on the individual characteristic factor. Conclusion As the results, the individual characteristic factor by the inspection of body shape is very important item of the four methods of diagnosis(四診) and the differentiation of syndromes(辨證). And therefore the process on four methods of diagnosis and differentiation of syndromesis is necessary to divide the signs of individual characteristic factor and the signs of disease.

• 한국정밀공학회지
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• 제29권3호
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• pp.279-288
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• 2012

The material removal mechanism in machining is significantly affected by the cutting edge geometry. Its effect becomes even more substantial when the depth of cut is relatively small as compared to the characteristic length which represents the shape and size of the cutting edge. Conventionally, radius or focal length has been employed as the characteristic length with the assumption that the shape of cutting edge is round or parabolic. However, in reality, there could be various ways to determine the radius or focal length even for the same tool edge profile, depending on the region to be considered as cutting edge in the measured profile and the constraints to be set in constructing the best fitted circle or parabola. In this regard, the present study proposes various models to determine the characteristic length in terms of radius or focal length. Their physical compatibility are validated by carrying out 2D orthogonal cutting experiments using inserts with a wide range of characteristic length ($30{\sim}180\;{\mu}m$ in terms of radius) and then by investigating the correlation between the characteristic length and the cutting forces. Such validation is based on the common belief that the larger the characteristic length is, the blunter the cutting edge is and the higher the cutting forces are. Interestingly, the results showed that the correlation is higher for the radius or focal length obtained with a constraint that the center of best fitted circle or the focus of the best fitted parabola should be on the bisectional line of the wedge angle of tool.

• 대한토목학회논문집
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• 제33권3호
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• pp.957-964
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• 2013

본 논문은 침수특성치를 이용한 도시유역의 침수위험성 평가방법을 제시하는 연구이다. 2010년 9월 21일 청계천상류의 효자배수분구(광화문 광장일대)에서 발생한 침수피해를 XP-SWMM 2010을 이용하여 모의하였다. 강우발생빈도별, 지속시간별로 관로첨두유출량 값을 구하여 침수상태를 분석한 결과 관로 내 첨두유출량만으로는 침수상태를 충분히 해석할 수 없음을 확인 할 수 있었다. 따라서 도시지역의 침수피해규모를 표현할 수 있는 침수특성치 6가지를 새롭게 정의하였으며 발생가능한 강우조합(강우량, 강우지속시간)을 침수특성치별로 산정하여 침수위험성 평가방법을 연구하였다. 모의 결과를 침수특성치별로 강우조합에 중첩하여 등치선도로 나타낸 "발생가능강우별 침수특성 등치선도"를 개발하여 이를 근거로 발생할 수 있는 모든 강우형태에 대한 침수위험성을 평가할 수 있음을 확인할 수 있었다. 또한 유역의 상태가 변하거나 치수계획규모를 변화시키는 것에 대한 침수특성치별 침수규모 해소정도를 쉽게 파악 할 수 있음을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.160-163
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• 2009

HPA(High Power Amplifier)는 무선통신 시스템에서 필수적으로 요구되는 요소 중의 하나다. 그러나 전력 증폭기는 비선형 특성을 가지고 있으며 신호의 비선형 왜곡을 유발 시키고 인접채널 간섭을 심화시켜 시스템의 효율을 떨어뜨린다. 이러한 문제점을 해결하기 위해 많은 선형화 기법들이 제시되어왔다. 다항식 사전왜곡 기법은 증폭기로 입력되는 신호가 미리 증폭기의 역 특성을 갖도록 하는 기법으로 다항식을 통하여 증폭기를 모델링하기 때문에 수렴 속도가 빠르고 다른 기법들에 비해 좋은 성능을 보인다. 하지만 다항식으로 역 비선형 특성을 구할 경우, 증폭기의 포화영역에서 역 비선형 특성이 거의 무한대가 되어야 하기 때문에 선형화기의 성능이 크게 떨어진다. 본 논문에서는 이러한 문제점을 해결하기 위하여 PAPR(Peak-to-Average Power Ratio) 기법을 적용하여 다항식 사전왜곡 기법의 성능을 향상 시켰다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.692-692
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• 2007

• Korean Journal of Mathematics
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• 제9권1호
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• pp.1-7
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• 2001

In this paper, we define and study Gauss sums over Galois rings of characteristic 4. In particular, we give the absolute value of Gauss sum over Galois rings of characteristic 4.

• Korean Journal of Mathematics
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• 제11권2호
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• pp.161-167
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• 2003

The purpose of this paper is to study and characterize the notions of characteristic 0 and weakly almost periodicity in flows. In particular, we give sufficient conditions for the weakly almost periodic flow to be almost periodic.

• East Asian mathematical journal
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• 제26권3호
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• pp.379-387
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• 2010

In this paper, we prove that the extension ideal of a fuzzy characteristic ideal of a positive implicative BCK-algebra is a fuzzy characteristic ideal. We introduce the notion of the extension of intuitionistic fuzzy ideal of BCK-algebras and some properties of fuzzy intuitionistic ideal extensions of BCK-algebra are investigated.

• 한국통신학회논문지
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• 제26권7A호
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• pp.1257-1263
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• 2001

In the paper, the p-ranks and characteristics polynomials of cyclic difference sets are derived by expanding the trace expression of their characteristic sequences. By using this method, it is shown that the 3-ranks and characteristic polynomials of Helleseth-Kumar-Martinsen (HKM) difference set and Lin difference set can be easily obtained.