• Title/Summary/Keyword: Van

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2차원 층상 물질인 GaS, GaSe의 Van der Waals 상호작용에 대한 제일원리연구

  • 차선경;안다빈;신은하
    • EDISON SW 활용 경진대회 논문집
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    • 제4회(2015년)
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    • pp.400-404
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    • 2015
  • 2차원 물질인 metal mono chalcogenides(MMC) 중 GaS와 GaSe를 대상으로 하여 층과 층 사이의 van der Waals(vdW) 상호작용을 density functional theory(DFT) 계산을 이용해 연구하였다. Local density approximation(LDA)와 generalized gradient approximation (GGA)의 두 가지 다른 exchange correlation functional을 이용하고, 또한 두 개의 층 사이에 작용하는 van der Waals 상호작용을 고려한 LDA-D2, GGA-D2 계산을 수행하였다. 이와 같은 네 가지 방법으로 층간거리를 바꾸어 binding energy curve를 계산하였다. 그 결과 GGA-D2계산이 MMC의 층간 상호 작용을 가장 잘 기술하였다.

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A NEW q-ANALOGUE OF VAN HAMME'S (G.2) SUPERCONGRUENCE FOR PRIMES p ≡ 3 (mod 4)

  • Victor J. W. Guo;Xiuguo Lian
    • 대한수학회보
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    • 제60권3호
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    • pp.775-783
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    • 2023
  • Van Hamme's (G.2) supercongruence modulo p4 for primes p ≡ 3 (mod 4) and p > 3 was first established by Swisher. A q-analogue of this supercognruence was implicitly given by the first author and Schlosser. In this paper, we present a new q-analogue of Van Hamme's (G.2) supercongruence for p ≡ 3 (mod 4).

n-Propanol+acetic acid 및 n-propanol+n-propionic acid 계의 하부 인하점 측정 및 예측 (The Measurement and Estimation of Lower Flash Points for n-Propanol+Acetic acid and n-Propanol+n-Propionic Systems)

  • 하동명;이성진
    • 한국안전학회지
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    • 제22권4호
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    • pp.37-42
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    • 2007
  • Flash points for the flammable binary systems, n-propanol+acetic acid and n-propanol+n-propionic acid, were measured by Cleveland open cup tester. The Raoult's law, the van Laar equation and the UNIQUAC equation were used for predicting flash points and were compared with experimentally-derived data. The calculated values based on the van Laar and UNIQUAC equations were found to be better than those based on the Raoult's law. And the predictive curve of the flash point prediction model based on the UNIQUAC equation described the experimentally-derived data more effectively than was the case when the prediction model was based upon the the van Laar equation.

van der Pauw와 four point probe 방법에 의한 반도체 웨이퍼의 면저항 비교 (Comparison of van der Pauw method with FPP method in Sheet Resistance Measurements of Semiconductor Wafer)

  • 강전홍;김한준;유광민;한상옥;김종석;박강식;구경완
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1634-1636
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    • 2004
  • 반도체 웨이퍼의 면저항을 정밀 측정하는 대표적인 두가지 방법인 4탐침(four point probe)방법과 van der Pauw방법으로 반도체 웨이퍼의 면저항을 비교평가 하였다. 4탐침방법에 의한 측정 시스템을 사용하여 웨이퍼의 전체 면에 대하여 면저항을 측정하고, 같은 웨이퍼의 가장자리 네 지점에 탐침 전극을 구성한 후 van der Pauw 방법으로 면저항을 측정한 결과 4탐침 방법에 의한 측정결과를 기준으로 1 %이하의 일치도를 나타냈다.

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3 차원 결맞음 결상을 위한 파면 접힘 간섭계 (Wavefront Folding Interferometer for 3-dimensional Coherence Imaging)

  • 오세백;홍영주;곽윤근;김수현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.755-759
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    • 2004
  • The van Cittert-Zernike theorem has been used in radio astronomy. Recently, the van Cittert-Zernike theorem has been tried to 3D source reconstruction. A couple of interferometer has been used in 3D coherence imaging like Michelson Stellar Interferometer and Rotational Shearing Interferometer. We propose a new type of interferometer, which is a wavefront folding interferometer with a corner cube. By characteristics of the corner cube, it is capable of measuring both mutual intensity and cross spectral density function, and it is very easy to align and robust to disturbance. We simulate the feasibility of this interferometer setup by simulation of point source reconstruction.

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The Lower Flash Points of the n-Butanol+n-Decane System

  • Dong-Myeong Ha;Yong-Chan Choi;Sung-Jin Lee
    • 한국화재소방학회논문지
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    • 제17권2호
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    • pp.50-55
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    • 2003
  • The lower flash points for the binary system, n-butanol+n-decane, were measured by Pensky-Martens closed cup tester. The experimental results showed the minimum in the flash point versus composition curve. The experimental data were compared with the values calculated by the reduced model under an ideal solution assumption and the flash point-prediction models based on the Van Laar and Wilson equations. The predictive curve based upon the reduced model deviated form the experimental data for this system. The experimental results were in good agreement with the predictive curves, which use the Van Laar and Wilson equations to estimate activity coefficients. However, the predictive curve of the flash point prediction model based on the Willson equation described the experimentally-derived data more effectively than that of the flash point prediction model based on the Van Laar equation.

DESIGN AND CONSTRUCTION ASPECTS OF A ZERO INERTIA CVT FOR PASSENGER CARS

  • Van Druten, R.M.;Van Tilborg, P.G.;Rosielle, P.C.J.N.;Schouten, M.J.W.
    • International Journal of Automotive Technology
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    • 제1권1호
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    • pp.42-47
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    • 2000
  • This paper concentrates on the design and construction aspects of a transmission for a mid-class passenger car with internal combustion engine. The transmission, consisting of a Continuously Variable Transmission (CVT) with a Van Doorne V-belt, a planetary gear set and a compact steel flywheel is used to prove the concept of mechanical torque assist. The design goal is to obtain a proof of concept transmission with maximal efficiency, using proven transmission technology. With the developed so called Zero Inertia CVT, the fuel economy of the car is improved by operating the engine at its fuel optimal operating line. To achieve a good vehicle acceleration response, the flywheel assists the powertrain mechanically.

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카오스 이동 로봇에서의 장애물 회피 기법 (Obstacle Avoidance Technique for Chaotic Mobile Robot)

  • 배영철;김천석
    • 한국정보통신학회논문지
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    • 제8권8호
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    • pp.1692-1699
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    • 2004
  • 본 논문에서는 카오스 궤적 표면에서 불안정한 리미트 사이클을 가지는 장애물 회피 기법을 제안하였다. 카오스 궤적 표면의 모든 장애물은 불안정한 리미트 사이클을 가지는 Van der Pol 방정식으로 가정하였다. 하나 또는 몇 개의 Van der Pol 장애물과 고정 장애물을 로봇이 피해가는 과정을 결과로 나타내었다.

가상주행환경 기반 초음파 센서의 승합차 측면 보행자 인식 (Pedestrian Detection Using Ultrasonic Distance Sensors Based on Virtual Driving Environments)

  • 윤현철;최주용
    • 한국자동차공학회논문집
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    • 제25권3호
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    • pp.309-316
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    • 2017
  • In shuttle vans designed to transport children, the recognition of a child's approach and departure is very important. Ultrasonic sensors are generally used for a short distance around a vehicle. Although ultrasonic sensors are cheaper than other ADAS sensors, the number of sensors installed in a van should be optimized. In order to recognize the presence of a child around a shuttle van, this paper proposes the placement of ultrasonic sensors in the van. Considering the turning radius of the van and the distance from each sensor to a child, collision risk is classified as 'safe', 'warning', and 'danger'. The sensor placement and the recognition algorithm are verified in a virtual driving environment.

말레비치(K.Malevich)의 절대주의 회화(絶對主義 繪畵)와 미스 반 데르로에(MiesvanderRohe)의 건축사상(建築思想)에 관한 비교연구(比較硏究) (A Study on the effect Malevich's Suprematism on Architectural Ideology of Mies van der Rohe)

  • 이호정
    • 한국디지털건축인테리어학회논문집
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    • 제10권3호
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    • pp.47-52
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    • 2010
  • This study aims to compare the Malevich's 'non-objectivity' and Mies van der Rohe's 'almost nothing'. K. Malevich who, as a painter, was a pioneer of abstract art and an initiator of Suprematism, was sought an ultimate value of art to non objective world, namely non of consciousness or a world of a non-being, In the same way, 'Mies van der Rohe was also sought for architectural space of non objectivity, as non of objective, being introduced 'less is more' or 'almost nothing' to architectural space.