• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.266-268
• /
• 2005

Recently, the ability of sensing obstacles by oneself and creating suitable moving path in mobile robots are required to provide various kinds automation services. Therefore, in this paper, we studied the avoidance behavior of mobile robots from dynamic obstacles using potential function that minimizes distance and time. We examined the performance of the proposed algorithm by comparing the method of based on the geometrical experience in simulations.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제2권1호
• /
• pp.163-181
• /
• 1998

The paper deals with some aspects of early childhood geometry in the Czech Republic. Children's first geometrical experiences come from real life. In our opinion, there exist four types of geometrical experience which can be called the partition of space, the filling of space motion in space and the dimension of space. We distinguish three levels of the mathematical learning process: a spontaneous level, an operational level and a theoretical level.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제1권2호
• /
• pp.163-181
• /
• 1997

The paper deals with some aspects of early childhood geometry in the Czech Republic. Children's first geometrical experiences come from real life. In our opinion, there exist four types of geometrical experience which can be called the partition of space, the filling of space motion in space and the dimension of space. We distinguish three levels of the mathematical learning process: a spontaneous level, an operational level and a theoretical level.

• 대한수학교육학회지:학교수학
• /
• 제1권1호
• /
• pp.109-122
• /
• 1999

In this paper we give a description of students' obstacles in their learning of geometry, especially resulted from their confusing a physical drawing with a figure, a geometrical object which a physical drawing represents. In computer-based teaching-learning environment, we could relieve such obstacles through providing students for experiences in which they must focus on elements of a figure and relations of them. But there may be potential in computer-based environment if we offer students only visual experience for validity of geometrical gacts: students' lack of understanding for need of proof and experience of cognitive obstacles which is very important for students to reflect their thinking and activities. Thus an didactical treatment must follows, which we also give an example.

• 대한수학교육학회지:수학교육학연구
• /
• 제23권4호
• /
• pp.585-604
• /
• 2013

본 연구는 증명 자체가 일반성을 전제로 한다는 사실에도 불구하고, 다수의 학생들은 증명을 수행한 후에도 기하 정리의 일반성을 인식하지 못한다는 문제로부터 출발한다. 이 문제를 경험적 확신, 도형 표현의 특수성 및 기하 변수의 역할 등의 측면에서 조명함으로써 그 해결책으로서 동적기하환경을 제안한다. 곧 동적기하환경에서의 문제해결 경험이 기하 정리의 일반성 인식에 미치는 영향을 조사하고 교육적 시사점을 제공하는 것을 목적으로 한다. 이를 위해 기하 단원에서의 증명 학습 경험을 토대로 증명을 할 수 있지만 정리의 일반성을 인식하지 못한 중학교 3학년 학생 4명을 대상으로 동적기하환경을 제공하고 그 탐구과정에서 학생들의 일반성 인식과 관련한 인지 변화를 관찰, 분석하였다. 분석 결과를 토대로 동적기하환경이 학생들의 기하정리의 일반성 인식에 미치는 효과와 교육적 시사점에 대해 논의하였다.

• 한국수학사학회지
• /
• 제17권1호
• /
• pp.87-96
• /
• 2004

This article dealt with two approaches, algebraic and geometric approaches in terms of Pythagoreans theorem. As mathematics evolves, many theorems had been developed beginning with geometric approaches. However, the algebraic techniques that survive these days are so powerful and generalized in school curriculum. So, if students have more chances to see mathematical properties in geometrical ways, they can experience how beautiful and meaningful they are through the process of the advent of them. Also, it was to try to develop an insight into their applications to other problems.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.473-473
• /
• 2009

There have been many academic researches on the aerodynamic design of wind turbine based on blade element method (BEM) and momentum theory (MT, or actuating disk theory). However, in the real world, the turbine blade design requires many additional constraints more than theoretical analysis. The standard procedure is studied in the present paper to design new blades for the wind turbine system ranged from the small size from 1 to 10 kW. From the experience of full design of a 10 kW blade, the authors tried to set up a standard procedure for the aerodynamic design based on IEC 61400-2. Wind-turbine scale, rotating speed, and geometrical chord/twist distribution at the segmented span positions are calculated with a suitable BEM/MT code, and the geometrical shape of tip and root should be modified after considering various parameters: wing-tip vortex, aerodynamic noise, turbine efficiency, structural safety, convenience of fabrication, and even economic factor likes price, etc. The evaluated data is passed to the next procedure of structural design, but some of them should still be corresponded with each other: the fluid-structure interaction is one of those problems not yet solved, for example. Consequently, the design procedure of small wind-turbine blades is set up for the mass production of commercial products in this research.

• 복식문화연구
• /
• 제7권5호
• /
• pp.122-139
• /
• 1999

Paco Rabanne, who has created experimental and prophetic avant-garde fashion by cutting edge techniques and revolutionary new materials, is known as one of the most influential fashion designer of modern times. The purpose of this study is to analyze the various factors, including some major artistic movements, which influenced on the formative characteristics of Paco Rabanne\`s fashion design. First, Paco Rabanne\`s fantastic new materials is also influenced by his study in architecture and his own fantasies -which other people can hardly imagine- during his early childhood. Second, light one of the most important element in Paco Ranbanne\`s fashion design, shows some influence of medieval symbols of love and salvation. Third, the artistic trends which influenced on Paco Rabanne\`s fashion include surrealism, opart, and kinetic art. His use of new materials and avant -garde style represents the influence of surrealism. his experimental use of waving plastics and glittering metal during his early period is especially related with opart and kinetic art in the early 1960s which emphasize the artistic effect of light and movement. Fourth, the geometrical figures like triangles, rectangles, and circles represent the influence of Egyptian architecture like pyramids and the geometrical characteristics of Eguptian art. Fifth, Paco Rabanne\`s distinctive use of metal chains in his fashion shows the influence of the chain mail hauberk, the medieval knightly armour. By using the medieval material Paco Rabanne properly expressed the modern person\`s pain and suffering. Sixth, the ethnic elements of Egypt, Africa, Spain, and Japan reflect the experience in his former lives he insists he lived. The ethnic elements of his dresses emphasize the natural vitality and inheritance from the past.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1993년도 추계학술대회 논문집
• /
• pp.200-205
• /
• 1993

The automatic forming sequence design system can determine desirable operation sequences even if they have little experience in the design of cold forging process. This system is proposed,which generates forming sequence plans for the multistage cold forging of zxisymmetrical solid products. Since the process of metal forming can be considered as a transformation of geometry, treatment of the geometry of the product is a key in planning processes. Forming sequence for the part can be determined by means of primitive geometries such as cylinder,cone, convex, and concave. By utilizing this geometrical characteristics(diameter,height, and radius),the product geometry is expressed by a list of the pnmitive geometries. Accordingly, the forming sequence design is formulated as the search problem which starts with a billet geometry and finishes with a given product one. Using the developed system, the sequence drawing with all dimensions, which includes the proper sequence of operations for the part, is generated under the environment of AutoCAD. The preliminary choice of some feasible forming sequences can verify by using the finite element simulation.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.434-440
• /
• 2000

This study is focused on the performance prediction and design of the centrifugal pump with optimum shape. Design and analysis of centrifugal pump rely on experience of designer due to many fluid mechanical and geometrical variables. In this study, a design method was developed with experimental factors and analysed the method by comparition with 2nd-order vortex panel method. Impeller is the most important component affecting the performance of the centrifugal pump. The predicted total head for three cases, of which designs were determined by this method, agrees well with a particular commercial pump. This study shows that satisfactory performance of an optimal pump shape can be obtained through the automatic design routine.