• 한국산학기술학회논문지
• /
• 제9권5호
• /
• pp.1150-1153
• /
• 2008

본 논문은 탄소 나노 튜브 (CNT)로 형성된 다중벽 탄소 나노튜브의 진동 특성을 분자 역학적 시뮬레이션 방법에 의해 해석하였다. 이로부터 이중벽 탄소 나노튜브에 비하여 다중벽 탄소 나노튜브의 경우 진동 주파수 분할이 발생됨을 분석하였다. 또한 세개의 주파수 발생자로써의 4차 벽, 5차 벽, 6차 함수 벽으로 된 오실레이터와 직경으로부터 독립적인 적합성 제안을 위해 지속적인 세 개의 정점이 나타나는 것으로 분석되었다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2010-2014
• /
• 2005

Object detection and parameter estimation in point cloud data is a relevant subject to robotics, reverse engineering, computer vision, and sport mechanics. In this paper a software is presented for fully-automatic object detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting. The newly developed algorithms for orthogonal distance fitting (ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. Curvature analysis of the local quadric surfaces fitted to small patches of point cloud provides the necessary seed information for automatic model selection, point segmentation, and model fitting. The performance of the software on a variety of point cloud data will be demonstrated live.

• Advanced Composite Materials
• /
• 제16권1호
• /
• pp.63-81
• /
• 2007

Based on the Kirchhoff hypothesis of normal-remain-normal, the present work analyses piezoelectric laminated plates, wherein poled piezoelectric laminae are transversely isotropic and function as actuators. A quadric electric field is induced inside a piezoelectric lamina under a given applied voltage and mechanical bending. The governing equations for the piezoelectric laminated plate derived from the principle of virtual work in terms of the electric enthalpy have the same forms as those for a conventional composite laminated plate. We use rectangular sandwich plates of Al/PZT/Al and PZT/Al/PZT with four simply supported edges to demonstrate the prediction of the maximum bending stress in the PZT layer. The analytic solutions are verified by three-dimensional finite element analysis.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.794-801
• /
• 2006

The linkage framework of geometric modeling and analysis based on the NURBS technology is developed in this study. The NURBS surfaces are generated by interpolating the given set of data points or by extracting the necessary information to construct the NURBS surface from the IGES format file which is generated by the commercial CAD systems in the present study. Numerical examples shows the rate of displacement convergence according to the paramterization methods of the NURBS surface. NURBS can generate quadric surfaces in an exact manner. It is the one of the advantages of the NURBS. A trimmed NURBS surface that is often encountered in the modeling process of the CAD systems is also presented in the present study. The performance of the developed geometrically exact shell element integrated with the exact geometric representations by the NURBS equation is compared to those of the previous reported FE shell elements in the selected benchmark problems.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2005년도 추계학술발표대회 및 정기총회
• /
• pp.1385-1388
• /
• 2005

최근 3 차원 스캐닝(Scanning) 기술의 발달로 형상 및 색상 정보 데이터를 동시에 획득할 수 있게 되었다. 특히 한번의 측정으로 다량의 데이터를 확보할 수 있기 때문에 3 차원 데이터의 정합(Registration) 및 병합(Merging) 과정에서 계산량이 증가하게 된다. 또한 정합과 병합 후의 대용량 데이터 자체로는 3 차원 모델의 저장, 전송, 처리 및 렌더링(Rendering) 등의 과정에서 어려움이 있다. 따라서 모델의 기하 정보와 색상, 질감, 곡률 등의 속성 정보를 유지하면서 데이터의 양을 감소시키는 메쉬 간략화 기술이 필요하다. 현재 널리 쓰이는 이차 오차 척도(Quadric Error Metric) 방법으로 메쉬를 극심하게 감소하게 되면 오차가 누적되어 기하 정보 및 속성 정보가 소실된다. 본 연구에서는 이를 방지하기 위해 이차 오차 척도 감소화 과정에서 곡률과 색상 기반의 정점 재조정 방법을 제안한다.

• Bulletin of the Korean Chemical Society
• /
• 제10권1호
• /
• pp.34-39
• /
• 1989

The relationship between the solute retention and physical parameters describing the interaction between the solute and mobile phase was investigated to predict the solute retention easily in RPLC. The retention data of monosubstituted benzenes were measured on the $\mu$-Bondapak C18 and phenyl columns with methanol-water systems. The linear relationship between dielectric increment($\epdilon'$) and retention data was observed. When the solute form hydrogen bonding with solvent molecules, the slope of the ln k' vs. $\epdilon'$ plot is changed as the compositions is varied. The quadric relationship between mixed solvent solubility parameter ($\delta$M) and retention data was observed.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2014년도 추계학술대회
• /
• pp.701-704
• /
• 2014

본 논문에서는 음료 판매 데이터 분석 및 판매량을 예측하는 방법을 제안하고자 하였다. 이를 위해 날씨와 음료 판매량이 상관관계가 있다고 가정하고, 온도, 습도를 입력으로 하여 판매량을 출력으로 하는 다항식 함수 관계를 모델링하였다. 본 논문에서는 제안한 방식의 유용성을 확인하기 위해 카페의 음료 판매 데이터를 2014년 2월부터 약 4개월 동안 수집하였고, 판매량 예측 알고리즘의 성능이 우수함을 확인하였다.

• 충청수학회지
• /
• 제34권2호
• /
• pp.181-188
• /
• 2021

Let X be a nondegenerate reduced closed subscheme in ℙⁿ. Assume that π_q : X → Y = π_q(X) ⊂ ℙ^n-1 is a generic projection from the center q ∈ Sec(X) \ X where Sec(X) = ℙⁿ. Let Z be the singular locus of the projection π_q(X) ⊂ ℙ^n-1. Suppose that I_X has the almost minimal presentation, which is of the form R(-3)^β_2,1 ⊕ R(-4) → R(-2)^β_1,1 → I_X → 0. In this paper, we prove the followings: (a) Z is either a linear space or a quadric hypersurface in a linear subspace; (b) $H^1({\mathcal{I}_X(k)})=H^1({\mathcal{I}_Y(k)})$ for all k ∈ ℤ; (c) reg(Y) ≤ max{reg(X), 4}; (d) Y is cut out by at most quartic hypersurfaces.

• 대한수학회보
• /
• 제59권2호
• /
• pp.407-417
• /
• 2022

Archimedes proved that for a point P on a parabola X and a chord AB of X parallel to the tangent of X at P, the area of the region bounded by the parabola X and the chord AB is four thirds of the area of the triangle ∆ABP. This property was proved to be a characteristic of parabolas, so called the Archimedean characterization of parabolas. In this article, we study strictly convex curves in the plane ℝ². As a result, first using a functional equation we establish a characterization theorem for quadrics. With the help of this characterization we give another proof of the Archimedean characterization of parabolas. Finally, we present two related conditions which are necessary and sufficient for a strictly convex curve in the plane to be an open arc of a parabola.

• 한국산업융합학회 논문집
• /
• 제20권4호
• /
• pp.257-263
• /
• 2017

The following thesis researched into the characteristics of electrolytic ion water with different levels of electrical conductivity by adding NaCl into tap water which is for experimental use in multi-layered electrolytic ion water generator. Electrolytic ion water is generated by underwater electrolysis and the electrolysis generator has a simple structure, is easy to control and is highly utilized in industries. Electrolytic ion water is useful in many areas since it has a superior sterilizing power, has no possibility of secondary pollution itself as water and removes active oxygen. In the experiment, we used tap water with NaCl excluded and water with three different levels of electrical conductivity by changing NaCl concentration levels into three levels. The features of current and voltage in electrolytic ion water represented a form of quadric instead of the linear characteristic following ohm's law. As well, as the electric conductivity of water and applied voltage increased, we were able to generate much stronger acid water and alkali water.