• Journal of Power Electronics
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• 제18권2호
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• pp.615-626
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• 2018

To ensure a DC current path and avoid large voltage overshoot of the DC-link inductor, alternating PWM pulses in the current-source rectifier should be supplemented by overlap time, which generates an overlap current and causes input current distortion. In this study, the influence of overlap time is illustrated by comparing the AC-side current before and after overlap time is added. The overlap current distribution caused by overlap time is discussed under different modulation carriers, including triangle carrier, positive-going carrier, and negative-going carrier. The quantitative relationship between the extra harmonics of the AC-side current and overlap time is based on the Fourier analysis. Based on the commutation analysis, a new carrier modulation scheme that can restrain overlap current is proposed. A 3 kW prototype is established to verify the effectiveness of the influence of overlap time and the proposed restraining modulation scheme.

• 대한화학회지
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• 제23권3호
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• pp.125-131
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• 1979

한 쌍의 slater type orbitals에 대한 two overlap integrals을 계산하는 방법이 Mulliken등에 의하여 발전되었다. 이 방법으로 two center integrals을 계산하기 위해서는 한쌍의 Slater type orbital,에 대한 극좌표들 타원좌표로 변환해야한다. 두 점에 위치한 Slater type orbital을 공통좌표상에 전개시키는 새로운 방법 즉 spherical harmonics의 전개방법이 two center overlap integrals, 을 계산하는데 응용되었다. 이 새로운 방법에서는 Slater type orbitals, 을 기준점에 대해 전개시키는 것이 필요하다. 본 연구에서는 two center overlap integral을 계산하기 위한 spherical harmonics 전개방법을 $|3s{\g}$, $|5s{\g}$및 $|5s{\g}$에 까지 확장시켰다. 이들 원자궤도함수의 전개식을 사용하여 two center overlap integrals의 기본식을 유도하였으며, 이 기본식을 사용하여 가상적인 NO 분자에 대한 two cunter overlap integrals의 계산값이 이미 보고된 값과 일치하였다.

• 정보과학회 논문지
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• 제45권3호
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• pp.200-210
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• 2018

여러 DNA 리드 시퀀스가 주어졌을 때, de novo 시퀀스 어셈블리는 레퍼런스 시퀀스 없이 하나의 시퀀스를 재조립한다. 재조립을 위해 de novo 시퀀스 어셈블리는 리드 사이의 모든 겹침을 계산하는 overlap 단계가 필요하다. Overlap 단계는 전체 연산 중 비용이 가장 많이 들기 때문에 어셈블리의 계산 성능을 좌우한다. 여러 분야에서 overlap 단계를 위한 연구가 많이 발표되고 있는데, 그 중 가장 최신의 세 연구 결과는 Readjoiner, SOF, Lim-Park 알고리즘이다. 최근 염기 분석기술의 큰 발전으로 DNA 리드 데이터 셋을 기존보다 저비용으로 대량 생산하는 것이 가능해져 DNA 리드 데이터 셋을 생성하는 여러 플랫폼들이 개발되었다. 각 플랫폼마다 생성하는 데이터 셋의 통계적 특성이 다르기 때문에 overlap 단계의 성능 평가 시 다양한 통계적 특성의 데이터 셋이 반영되어야 한다. 본 논문은 여러 통계적 특성을 가진 DNA 리드 데이터 셋을 이용하여 위의 세 알고리즘의 성능을 비교 분석한다.

• 만화애니메이션 연구
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• 통권49호
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• pp.87-112
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• 2017

중첩은 복수의 이미지들을 겹쳐 놓는 것으로 여러 가지 표현의 목적을 위해 사용된다. 중첩 가운데, 특히 움직임을 표현하기 위한 중첩은 운동의 과정을 분석, 종합하면서 예술의 여러 분야에서 활용되어 왔다. 이러한 움직임을 표현하는 중첩을 '동체중첩'이라고 명명하고, '하나의 화면에 단일 동체의 운동을 동시에 나열해 움직임을 표현하는 기법'으로 정의한다. 동체중첩은 회화와 사진과 같은 평면 예술에서 시작되었는데 이를 '정적인 동체중첩'으로 분류하고, 이를 이어서 영화와 애니메이션과 같은 영상예술로 발전한 동체중첩은 '동적인 동체중첩'으로 분류한다. 이러한 동체중첩의 중심에는 무엇보다도 동체중첩의 독자적인 예술성과 미학을 구현한 노먼 맥라렌의 작품 <빠 드 되>가 위치하며, 이 작품을 중심으로 동체중첩의 핵심 개념을 분석하고 그 선후에 대한 연구를 통해 동체중첩의 맥락과 예술적 성취를 확인한다. 그리고 오늘날 동체중첩은 디지털 테크놀로지의 발달에 힘입어 기술과 차원을 더욱 확장시키고 있다. 신기술을 활용한 새로운 동체중첩의 작업들은 <빠 드 되>를 매체적으로, 그리고 개념적으로 재해석해 동체중첩의 새로운 가능성을 보여 주는데 이러한 동체중첩의 경향과 전망에 관해 살펴본다. 이와 같이 <빠 드 되>를 중심으로 한 동체중첩에 관한 논의는 궁극적으로 동체중첩이 이룬 예술적 성취를 확인하고 그 의미와 새로운 가능성에 대해 고찰하는 계기를 제공한다.

• 전자공학회논문지B
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• 제32B권10호
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• pp.1280-1285
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• 1995

In this paper the optimized overlap driving scheme for improving the reduction problem of the operating voltage range occured by the overlap driving scheme proposed precedently and increasing the contrast ratio of screen image in the simple matrix LCDs is proposed. The characteristic estimation of the proposed method was performed in a condition that the number of scan electrodes was 120 and the threshold voltage of LC pixel was 2V and the overlap rate of scan signal was varied from 0% to 40% . As a result of estimation compared with the overlap driving scheme proposed precedently, this new method was certified as a method which it could increase the operating voltage range of the LC pixel by 16% in 20% overlap condition and it's operating voltage range was also increased very much with the increase of the overlap rate. Consequently this newly proposed method was certified as a method which it could maintain the improvement effect of the operating characteristics obtained by the overlap driving scheme proposed precedently with the big improvement in the contrast ratio of screen image.

• 대한화학회지
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• 제22권3호
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• pp.117-127
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• 1978

두점 A와 B에 위치한 Slater원자궤도함수의 spherical harmonics부와 지름부를 기준점 A를 중심으로 전개하여 공통좌표상에 기술하였다. 이 Slater 원자궤도함수의 전개식을 사용하여 two center overlap integral의 기본식을 유도하였으며 이 기본식을 이용하여 $CH_4,\;H_2O,\;NH_3,\;C_2H_6$ 및 $PH_3$ 분자의 two center overlap integral을 계산하였을 때 이 값이 Mulliken의 값과 일치하였다.

• 말소리와 음성과학
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• 제3권3호
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• pp.27-33
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• 2011

This paper explores two articulatory characteristics of inter-consonantal coordination observed in lingual-lingual (/kt/, /ks/) and labial-lingual (/pt/) sequences. Using electromagnetic articulometry (EMMA), temporal aspects of the lip movement and lingual movement (of the tongue tip and the tongue dorsum) were examined. Three sequences (/ks/, /kt/, /pt/) were investigated in two respects: gestural overlap in C1C2 and formation duration of coronals in C2 (/t/ or /s/). Results are summarized as follows. First, in a sequence of two stop consonants gestural overlap did not vary with order contrast or a low-level motor constraint on lingual articulators. Gestural overlap between two stop consonants was similar in both /kt/ (lingual-lingual; back-to-front) and /pt/ (labial-lingual; front-to-back). Second, gestural overlap was not simply constrained by place of articulation. Two coronals (/s/ and /t/) shared the same articulator, the tongue tip, but they showed a distinctive gestural overlap pattern with respect to /k/ in C1 (/ks/ (less overlap) < /kt/ (more overlap)). Third, temporal duration of the tongue tip gesture varied as a function of manner of articulation of the target segment in C2 (/ks/ (shorter) < /kt/ (longer)) as well as a function of place of articulation of the segmental context in C1 (/pt/ (shorter) < /kt/ (longer)). There are several implications associated with the results from Korean non-assimilating contexts. First, Korean can be better explained in the way of its language-specific gestural pattern; gestural overlap in Korean is not simply attributed to order contrast (front-to-back vs. back-to-front) or a physiological motor constraint on lingual articulators (lingual-lingual vs. nonlingual-lingual). Taking all factors into consideration, inter-gestural coordination is influenced not only by C1 (place of articulation) but also C2 (manner of articulation). Second, the jaw articulator could have been a factor behind a distinctive gestural overlap pattern in different C1C2 sequences (/ks/ (less overlap) vs. /kt/ and /pt/ (more overlap)). A language-specific gestural pattern occurred with reference to a physiological motor constraint on the jaw articulator.

• Journal of Welding and Joining
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• 제34권6호
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• pp.69-74
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• 2016

Because the pure titanium has superior corrosion resistance and formability compared with different material, it is widely used as material of welded heat exchanger. When the welding of heat exchanger is carried out, certain area in which welding start and end are overlapped occurs. The humping of back bead is formed in the overlap area due to partial penetration. Thus in this study, the experiments were carried out by changing the length and wave shape of overlap area, and then the weldabiliay was evaluated through the observation of microstructure, the measurement of hardness and tensile-shear strength test in the overlap area. When overlap length was 9.8mm, humping bead was suppressed. The microstructure of overlap area coarsened and its hardness increased due to remelting. As a result of tensile-shear strength test in the overlap area according to applying the wave shape control, it was confirmed that the overlap area applied wave shape control had more excellent yield strength and ductility.

• 대한방사선기술학회지:방사선기술과학
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• 제43권3호
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• pp.161-167
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• 2020

This study aimed to found out the effect of patellofemoral overlap distance by changing femur thickness and center X-ray angles in Merchant method images. Based on the femur thickness, it suggested tube angle minimizes overlap. It was conducted by Merchant method, a knee tangential view, and the image was obtained by changing the thigh thickness from 14 to 20 cm and the center ray angle from 60°, 57°, 55°. The images were measured by five researchers using a method of measuring the overlap, which was designed by them. The results showed at 60°, 57°, 55° angle, the patellofemoral overlap distance resulted in 0.47±0.66 to 20.89±0.65 cm, 2.26±0.28 to 15.73±0.62 cm, 1.39 ± 0.83 to 12.49 ± 0.37 cm. However, for 57° and 55°, no overlap in thickness under 14.5 and 14 to 15.5 didn't appear. it showed high correlation between femur thickness and overlap. The difference in the mean value of overlap in each group showed a statistically significant difference (p<0.01), all were classified as independent groups in the post-hoc test. In all images, the patellofemoral overlap distance increased as the thickness increased, and at the average thickness of Korean men and women, overlap decreased when reducing center ray. When conducting Merchant tests on Koreans, it was suggested it would be useful to use 57° angle because it minimize the effects of overlap and intrusions of tibia.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.769-772
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• 2014

비정질 InGaZnO 박막트랜지스터의 Gate Overlap 길이에 따른 NBS(Negative Bias Stress) 및 hot carrier 스트레스 후 시간별 문턱전압의 변화에 의한 소자신뢰도를 분석하였다. 측정에 사용된 소자는 비정질 InGaZnO TFT이며 채널 폭 $W=104{\mu}m$, 게이트 길이 $L=10{\mu}m$이며 Gate Overlap 길이는 $0,1,2,3{\mu}m$를 사용하였다. 소자 신뢰도는 전류-전압을 측정하여 분석하였다. 측정 결과, hot carrier 스트레스 후 Gate Overlap 길이가 증가할수록 문턱전압의 변화가 증가하였다. 또한, NBS 후에는 Gate Overlap 길이가 증가할수록 문턱전압의 변화가 감소하였고 장시간 스트레스 후에 hump가 발생하였다.