• 정보교육학회논문지
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• 제14권3호
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• pp.449-459
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• 2010

초등학교 도형 학습에 컴퓨터 프로그램을 활용하면 도형에 대한 다양한 조작 기능을 제공하여 학습의 효과를 높일 수 있으며, 탐구적 환경을 조성함으로써 교실 환경의 한계를 극복할 수 있다. 지금까지의 연구는 컴퓨터 프로그램을 활용한 도구들을 개발하였지만 콘텐츠 없이 도구이다. 본 연구는 Van Hieles의 기하 학습수준이론에 기초하여 초등학교 수학과 교육과정의 도형 영역을 분석하고, 초등학생들의 인지 수준에 적합한 도형 학습 문제 해결 도구(Geometry For Kids : GeoKids)를 개발한다. 학생들의 인지 수준을 고려하여 자와 컴퍼스를 대신할 수 있도록 만들었고, 원과 직선을 마우스를 사용하여 쉽게 그릴 수 있고, 보다 정확한 작도를 위하여 점과 원의 경계를 자동으로 인식하도록 구성하였다. 수학과 교육과정의 도형 학습 주제에 따라 GeoKids의 기능을 연계한 학습을 할 수 있다.

• 한국수학사학회지
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• 제20권1호
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• pp.57-72
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• 2007

최근 수학교육에서 펜토미노와 같은 절단 퍼즐들을 학습에 많이 활용하고 있다. 그러나 이런 퍼즐들의 개발 배경과 수학적 활용 방법에 대한 연구 부족으로 수학적 개념 도입이나 문제해결을 위한 소재로서 다양하게 사용되고 있지 못한 실정이다. 이 논문은 펜토미노를 수학 학습에서 효과적으로 활용하기 위하여 펜토미노와 같은 절단 퍼즐의 배경이 되는 기하학적 문제와 펜토미노의 개발에 관한 수학사적 배경을 알아보고, 제 7차 초등학교 교육과정의 수학 교과서에서 활용할 수 있는 단원과 여러 문헌에서 펜토미노를 활동한 자료를 조사하여 체계적인 수학 학습자료를 개발하는 기초 자료와 방향을 제시하는 데 그 목적이 있다.

• Advances in aircraft and spacecraft science
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• 제7권4호
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• pp.353-369
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• 2020

This paper presents the flutter analysis and optimum design of axially functionally graded box beam cantilever wing section by considering various geometric and material parameters. The coupled dynamic equations of the continuous model of wing system in terms of material and cross-sectional properties are formulated based on extended Hamilton's principle. By expressing the lift and pitching moment in terms of plunge and pitch displacements, the resultant two continuous equations are simplified using Galerkin's reduced order model. The flutter velocity is predicted from the solution of resultant damped eigenvalue problem. Parametric studies are conducted to know the effects of geometric factors such as taper ratio, thickness, sweep angle as well as material volume fractions and functional grading index on the flutter velocity. A generalized surrogate model is constructed by training the radial basis function network with the parametric data. The optimized material and geometric parameters of the section are predicted by solving the constrained optimal problem using firefly metaheuristics algorithm that employs the developed surrogate model for the function evaluations. The trapezoidal hollow box beam section design with axial functional grading concept is illustrated with combination of aluminium alloy and aluminium with silicon carbide particulates. A good improvement in flutter velocity is noticed by the optimization.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.365-369
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• 2009

Identification is considered to be among the main applications of inverse theory and its objective for a given physical system is to use data which is easily observable, to infer some of the geometric parameters which are not directly observable. In this paper, a parameter identification method using inverse problem methodology is proposed. The minimisation of the objective function with respect to the desired vector of design parameters is the most important procedure in solving the inverse problem. The conjugate gradient method is used to determine the unknown parameters, and Tikhonov's regularization method is then used to replace the original ill-posed problem with a well-posed problem. The simulation and experimental results are presented and compared.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2126-2131
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• 2005

Interactions of a humanoid with a human are important, when the humanoid is requested to provide people with human-friendly services in unknown or uncertain environment. Such interactions may require more complicated and human-like behaviors from the humanoid. In this work the arm motions of a human are discussed as the early stage of human motion imitation by a humanoid. A motion capture system is used to obtain human-friendly arm motions as references. However the captured motions may not be applied directly to the humanoid, since the differences in geometric or dynamics aspects as length, mass, degrees of freedom, and kinematics and dynamics capabilities exist between the humanoid and the human. To overcome this difficulty a method to adapt captured motions to a humanoid is developed. The geometric difference in the arm length is resolved by scaling the arm length of the humanoid with a constant. Using the scaled geometry of the humanoid the imitation of actor's arm motions is achieved by solving an inverse kinematics problem formulated using optimization. The errors between the captured trajectories of actor arms and the approximated trajectories of humanoid arms are minimized. Such dynamics capabilities of the joint motors as limits of joint position, velocity and acceleration are also imposed on the optimization problem. Two motions of one hand waiving and performing a statement in sign language are imitated by a humanoid through dynamics simulation.

• 산업경영시스템학회지
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• 제23권56호
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• pp.55-64
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• 2000

There is more than a single quality characteristic and they are often of varying or mixed target types. The purpose of this paper is to develop general strategies for solving the multiple response robust design problem. The desirability function provides an important tool to solve problems that have different types of target since the desirability values all the range between zero and one. Several combinations of arithmetic averages, geometric averages, and standard deviations are used in the various strategies to find the best design point.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제14권3호
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• pp.219-231
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• 2010

Mathematically, a proof is to create a convincing argument through logical reasoning towards a given proposition or a given statement. Mathematics educators have been working diligently to create environments that will assist students to perform proofs. One of such environments is the use of dynamic-geometry-software in the classroom. This paper reports on a case study and intends to probe into students' own thinking, patterns they used in completing certain tasks, and the extent to which they have utilized technology. Their tasks were to explore the shape-to-shape, shape-to-part, and part-to-part interrelationships of geometric objects when dealing with certain geometric problem-solving situations utilizing dissection-motion-operation (DMO).

• 지능정보연구
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• 제15권3호
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• pp.1-15
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• 2009

데이터 불균형 문제는 분류 및 예측 문제에서 하나의 범주에 속하는 표본의 수가 다른 범주들에 속하는 표본 수에 비하여 현저하게 적을 경우 나타난다. 데이터 불균형이 심화됨에 따라 범주 사이의 분류 경계영역이 왜곡되고 결과적으로 분류자의 학습성과가 저하되는 문제가 발생한다. 본 연구에서는 데이터 불균형 문제를 해결하기 위하여 Geometric Mean-based Boosting (GM-Boost) 알고리즘을 제안하고자 한다. GM-Boost 알고리즘은 기하평균 개념에 기초하고 있어 다수 범주와 소수 범주를 동시에 고려한 학습이 가능하고 오분류된 표본에 집중하여 학습을 강화할 수 있는 장점이 있다. 기업부실 예측문제를 활용하여 GM-Boost 알고리즘의 성과를 검증한 결과 기존의Under-Sampling, Over-Sampling 및 AdaBoost 알고리즘에 비하여 우수한 분류 정확성을 보여주었고 데이터 불균형 정도에 관계없이 견고한 학습성과를 나타냈다.

• 전자공학회논문지S
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• 제34S권7호
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• pp.78-88
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• 1997

A three dimensional-two spatical dimensions plus time-image segmentation is widely used in a very low bit rate image sequence coding because it can solve the region correspondence problem. Mathematical morphology is a very efficient tool for the segmentation because it deals well with geometric features such as size, shape, contrast and connectivity. But if the motion in the image sequence is large in time axis, the conventional 3D morphological segmentation algorithm have difficulty in solving region correspondence problem. To alleviate this problem, we propose the hierarchical image sequence segmentation algorithm that uses the region motion information. Since the motion of a region in previous level affects that in current level uses the previous motion information to increase region correspondence. Simulation result shows improved performance for sequence frames with large motion.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.552-552
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• 2000

In recent years, a number of successful nesting approaches have been developed by using the various heuristic algorithms, and due to their application potential several commercial CAD/CAM packages include a nesting module for solving the layout problem. Since a large portion of the complexity of the part nesting problem results from the overlapping computation, the geometric representation is one of the most important factors to reduce the complexity of the problem. The proposed part representation method can easily handle parts and raw materials with widely varying geometrical shape by using the redesigning modules. This considerably reduces the amount of processed data and consequently the run time of the computer. The aim of this research is to develop parametric macro for two-dimensional cutting stock on the Auto-CAD system. Therefore, this research can be called "pre-nesting"