• Title/Summary/Keyword: two-dimensional shapes

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Analysis for Triangles in Elementary School Curriculum and Textbook: Focusing on the Instructional Teaching and Learning Elements of 2-D Shapes (평면도형의 교수·학습 요소에 따른 삼각형에 관한 초등학교 교과서 분석)

  • Kwon, Misun
    • Education of Primary School Mathematics
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    • v.24 no.4
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    • pp.233-246
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    • 2021
  • Two-dimensional shapes have a great influence on elementary school students' learning and are closely related to other content areas. Therefore, in this study, The Teaching and Learning Elements that should be taught in two-dimensional shapes were extracted from the literature. It also was analyzed that revised mathematics textbooks in the year 2015 were properly implemented with the teaching and learning elements. As a result of the analysis, in the case of Understanding The Concept, the activities in the textbooks are not able to recognize 2-D shapes which are focusing on shapes of the actual object. In the case of Classifying two-dimensional shapes according to the Criteria, the classification criteria were presented differently from what was learned in the previous course. In the aspect of Applying the Concept, the activities in order to Discuss two-dimensional shapes were not sufficient. Lastly, in view of the fact the 2015 revised curriculum is not considered with the relationship between two-dimensional shapes. For that reason, the following Knowing Relationships parts are insufficiently presented; Understanding the Relationship Between shapes through Definitions and Properties, Identifying the relationship between shapes throughout classification activities, and Discussing the relationship between shapes. Based on the analysis result of two-dimensional shapes, it is suggested that the finding of this research helps to enlarge the teaching methodology of triangles and provide educational perspectives for development in other shape areas.

Application of the Genetic Algorithm to the Layout Problem of the Pane Considering Rotation (회전을 고려한 판재 배치 문제의 유전 알고리즘 적용)

  • 이금탁;김훈모
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.5
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    • pp.376-382
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    • 2000
  • A problem of relevant interest to some industries is that of the optimum two-dimensional layout. In this problem, one is given a number of rectangular sheets and an order for a specified number of each of certain types of two-dimensional regular and irregular shapes. The aim is to cut the shapes out of the sheets in such a way as to minimize the amount of waste produced. In this paper, we propose a genetic algorithms using rotation parameters by which the best pattern of layout is found.

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The Effects of Cooperative Learning on Children's Understanding of Geometry (협동학습활동이 유아 기하 학습에 미치는 영향)

  • Kwon, Young-Re;Lee, Kyung-Jin;Shin, Ok-Ja
    • Korean Journal of Child Studies
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    • v.32 no.2
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    • pp.71-85
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    • 2011
  • This study was carried out in order to better understand how cooperative learning effects the geometric understanding of young children. The geometry tasks used in the study included the geometric relationship between two dimensional shapes and three dimensional shapes, coordination, symmetry and transformation visualization and spacial reasoning. The subjects were composed of children aged five years and were taken from two kindergartens in a relatively new city close to Seoul. The experimental group of children the comparative learning in geometry. The comparative group of children were enrolled in a kindergarten that uses an the intergrated curriculum. The results indicated that cooperative learning impacted positively on the children's understanding of geometry. The specific results are as follows : The scores that the experimental acquired were higher in terms of p < .001 level. than the scores of the comparative group studying the geometric relationships between two dimensional shapes and three dimensional shapes, coordination, symmetry and transformation visualization & spacial reasoning.

A Study on the Design Method by Translating the Shape and Meaning of Chinese Character into Furniture (한자의 형태와 의미를 가구에 적용하기 위한 디자인 방법 연구)

  • 위한림
    • Journal of the Korea Furniture Society
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    • v.14 no.2
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    • pp.75-86
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    • 2003
  • The purpose of the study is to explore the possibilities for translating the images and meaning of Chinese characters into furniture. Using Chinese characters as designing sources for furniture has a lot of possibilities to inspire originative and creative works. When using images of characters, totally peculiar and new shapes of furniture which have great esthetic value can be considered. The functions of furniture are related to the meanings of characters. Therefore, the furniture could be recognized by the characters from which the works were formed. In the process of interpreting two dimensional letters in three dimensional forms, the graphic elements and values of the characters as two dimensional objects should be analyzed. In order to express the characters completely, both esthetic shapes and the essences of characters should be blended. For the effective translating work, the method of expression may require exaggerating, simplifying and abbreviating the shapes of characters.

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Three Dimensional Shape Morphing of Triangular Net (삼각망의 3 차원 형상 모핑)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.1
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    • pp.160-170
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    • 2008
  • Shape morphing is the process of transforming a source shape, through intermediate shapes, into a target shape. Two main problems to be considered in three dimensional shape morphing are vertex correspondence and path interpolation. In this paper, an approach which uses the linear interpolation of the Laplacian coordinates of the source and target meshes is introduced for the determination of more plausible path when two topologically identical shapes are morphed. When two shapes to be morphed are different in shape and topology, a new method which combines shape deformation theory based on Laplacian coordinate and mean value coordinate with distance field theory is proposed for the efficient treatment of vertex correspondence and path interpolation problems. The validity and effectiveness of the suggested method was demonstrated by using it to morph large and complex polygon models including male and female whole body models.

Free vibrations of inclined arches using finite elements

  • Chucheepsakul, Somchai;Saetiew, Wasuroot
    • Structural Engineering and Mechanics
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    • v.13 no.6
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    • pp.713-730
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    • 2002
  • This paper presents a finite element approach for determining the natural frequencies for planar inclined arches of various shapes vibrating in three-dimensional space. The profile of inclined arches, represented by undeformed centriodal axis of cross-section, is defined by the equation of plane curves expressed in the rectangular coordinates which are : circular, parabolic, sine, elliptic, and catenary shapes. In free vibration state, the arch is slightly displaced from its undeformed position. The linear relationship between curvature-torsion and axial strain is expressed in terms of the displacements in three-dimensional space. The finite element discretization along the span length is used rather than the total are length. Numerical results for arches of various shapes are given and they are in good agreement with those reported in literature. The natural frequency parameters and mode shapes are reported as functions of two nondimensional parameters: the span to cord length ratio (e) and the rise to cord length ratio (f).

An Analytic Analysis for a Two-Dimensional Floating and Fluid-Filled Membrane Structure (부유식 유체저장용 2차원 막구조물의 이론적 해석)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
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    • v.23 no.4
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    • pp.32-37
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    • 2009
  • An analytic similarity shape solution was studied for a two-dimensional floating and fluid-filled membrane structure. The static shape of a membrane structure can be expressed as a set of nonlinear ordinary differential equations. The integration of curvature leads to an analytic solution for the shape, which contains unknown boundary values. Matching the upper and lower shapes at the free surface incorporated with their buoyancy allowed the unknowns to be determined. Some characteristic values of similarity shapes were evaluated and shapes are illustrated for various density ratios and volume efficiency ratios.

Generation of Cutting Path Data for Two Steps of the Cutting Process in Full- Automated VLM-ST (VLM-ST 공정의 완전 자동화를 위한 2단계 절단 경로 데이터 생성 방법에 관한 연구)

  • 이상호;안동규;김효찬;양동열;박두섭;채희창
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.1
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    • pp.140-148
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    • 2004
  • A novel rapid prototyping (RP) process, a full-automated transfer type variable lamination manufacturing process (Full-automated VLM-ST) has been developed. In the full-automated VLM-ST process, a vacuum chuck and a rectilinear motion system transfer the EPS foam material in the form of the plate with two pilot holes to the rotary supporting stage. The supplied material is then cut into an automated unit shape layer (AUSL) with a desired width, a desired length, a desired slope on the side surface, and a pair of reference shapes, which is called the guide shape (GS)’, including two pilot holes in accordance with CAD data through cutting in two steps using a four-axis synchronized hotwire cutter. Then, each AUSL is stacked by setting each AUSL with two pilot holes in the building plate with two pilot pins, and subsequently, adhesive is applied onto the top surface of the stacked AUSL by a bonding roller and pressure is simultaneously given to the bottom surface of the stacked AUSL. Finally, three-dimensional shapes are rapidly and automatically fabricated. This paper describes the method to generate guide shapes in AUSL data for the full-automated VLM-ST process. In order to examine the applicability of the method to generate guide shapes, three-dimensional shapes, such as a piston shape and a human head shape, are fabricated from the full-automated VLM-ST apparatus.

Development of a Plate Manufacturing CAD/CAM Program for a Optimal Layout and Distributed Control System

  • Kim, Hun-Mo
    • Journal of Mechanical Science and Technology
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    • v.14 no.10
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    • pp.1089-1103
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    • 2000
  • A Problem of relevant interest to some industries is that of obtaining optimum two-dimensional layout. To solve this provlem, one is given a number of rectangular sheets and an order for a specified number of each of certain types of two-dimensional regular and irregular shapes. The aim is to cut the the shapes out of the sheets in such a way as to minimize the amount of waste produced. A DCS (Distributed Control System) is an integrated system which applies the decentralization concept to a control system handling both sequential and analog control. A DCS performs many operations such as data gathering, data processing, data storing and monitoring the operatin conditions for the operator. IN this paper, we propose a genetic algorithm based on rotation parameters from which the best pattern of layout is found as well as a layout method for better performance time. A DCS for the plate cutting process system, which is performed by a virtual system, is also identified.

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Three-Dimensional Analysis of the Shapes of Gathered Skirts (개더스커트 형상프로포션의 3차원적 해석)

  • Lee, Myung-Hee;Jung, Hee-Kyeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.11 s.158
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    • pp.1598-1607
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    • 2006
  • The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.