• Title/Summary/Keyword: Geometrical Figure

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Numerical Analysis of Electric Field Distribution Induced Inside a Realistic Brain Model Considering Conductivity Heterogeneity (전기전도도의 비균질성을 고려한 정밀 두뇌 모형 내부에서 유기되는 유도 전기장 분포해석)

  • Kim, Dong-Hun;Lee, Il-Ho;Won, Chul-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.2
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    • pp.314-319
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    • 2008
  • In this paper, the electric field distribution induced inside the brain during Transcranial Magnetic Stimulation(TMS) has been thoroughly investigated in terms of tissue heterogeneity and anisotropy as well as different head models. To achieve this, first, an elaborate head model consisting of seven major parts of the head has been built based on the Magnetic Resonance(MR) image data. Then the Finite Element Method(FEM) has been used to evaluate the electric field distribution under different head models or three different conductivity conditions when the head model has been exposed to a time varying magnetic field achieved by utilizing the Figure-Of-Eight(FOE) stimulation coil. The results show that the magnitude as well as the distribution of the induced field is significantly affected by the degree of geometrical asymmetry of head models and conductivity conditions with respect to the center of the FOE coil.

Understanding the properties of geometric figures through the linear transformation and its implication for school mathematics (일차변환 관점에서의 도형의 성질 이해 및 학교수학에의 시사점)

  • Hong, Gap-Ju
    • The Mathematical Education
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    • v.47 no.4
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    • pp.437-445
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    • 2008
  • On the basis of the meaning and general process of geometric proof through transformation concept and understanding the geometric properties of linear transformation, this study showed that the centroid of geometrical figure and certain properties of a parabola and an ellipse in school mathematics can be explained as a conservative properties through linear transformation. From an educational perspective, this is a good example of showing the process of how several existing individual knowledge can be reorganized by a mathematical concept. Considering the fact that mathematical usefulness of linear transformation can be revealed through an invariable and conservation concept, further discussion is necessary on whether the linear transformation map included in the former curriculum have missed its point.

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Revisiting Linear Equation and Slope in School Mathematics : an Algebraic Representation and an Invariant of Straight Line (직선의 대수적 표현과 직선성(直線性)으로서의 기울기)

  • Do, Jong-Hoon
    • Communications of Mathematical Education
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    • v.22 no.3
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    • pp.337-347
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    • 2008
  • 'Slope' is an invariant of a straight line and 'Linear Equation' is an algebraic representation of a straight line in the cartesian plane. The concept 'slope' is necessary for algebraically representing a geometrical figure, line. In this article, we investigate how those concepts are dealt with in school mathematics and suggest some improvement methods.

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Buckling Load of Lattice Timber Roof Structure considering Stiffness of Connection with Asymmetric Snow Load (접합부 강성과 비대칭 적설하중 적용을 통한 목조 래티스 지붕 구조물의 좌굴하중 특성)

  • Hwang, Kyung-Ju
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.1
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    • pp.69-76
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    • 2023
  • A timber lattice roof, which has around 30m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by stiffness of connection with various asymmetric snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the asymmetric snow load with the lower level stiffness of connection decreased the level of buckling load significantly.

A Dispersion Mean Algorithm based on Similarity Measure for Evaluation of Port Competitiveness (항만 경쟁력 평가를 위한 유사도 기반의 이산형 평균 알고리즘)

  • Chw, Bong-Sung;Lee, Cheol-Yeong
    • Journal of Navigation and Port Research
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    • v.28 no.3
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    • pp.185-191
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    • 2004
  • The mean and Clustering are important methods of data mining, which is now widely applied to various multi-attributes problem However, feature weighting and feature selection are important in those methods bemuse features may differ in importance and such differences need to be considered in data mining with various multiful-attributes problem. In addition, in the event of arithmetic mean, which is inadequate to figure out the most fitted result for structure of evaluation with attributes that there are weighted and ranked. Moreover, it is hard to catch hold of a specific character for assume the form of user's group. In this paper. we propose a dispersion mean algorithm for evaluation of similarity measure based on the geometrical figure. In addition, it is applied to mean classified by user's group. One of the key issues to be considered in evaluation of the similarity measure is how to achieve objectiveness that it is not change over an item ranking in evaluation process.

The Study of the Historic Origin and the Symbolism of Mehndi (멘디의 역사적 기원과 상징성에 대한 연구)

  • Jo, Eun-Young;Yoo, Tai-Soon
    • Fashion & Textile Research Journal
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    • v.6 no.3
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    • pp.297-306
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    • 2004
  • Mehndi, becoming a kind of body fashion in western advanced countries nowadays, is a exquisite, classical fashion form sublimated to traditional faith, medicine and designing art. As one of the cultural arts, especially transmitted by women, a individual tradition of the way how to do the mehndi and the design has been handed down from one culture to another over a thousand of years and it is extensively using in many area, all around world today. Mehndi was used as preparing for special events or celebrations in India, Africa, Central Asia in order to pray for happiness, good luck and calm hart 5000 years ago. Especially, it is concerned with romantic love or a wedding and takes important part of a traditional wedding reception and bride adorning in the culture of Hindu or Islam. In addition to adorning skin, mehndi has various symbols, meaning, function, that is, as a speechless language, in several cultures, it has common meaning such as attraction, protection, celebration. The design of mehndi has been in harmony with the figure, colors, skin types of the dress or the ornament. According to the region, religion, design, mehndi is divided into the design of India and Morocco mostly. Indian design mainly shows flowers and paisley pattern, people widely recognize this design to celebrate and adorn bride in wedding ceremony, still apply mehndi the present time. Moroccan mehndi design, representing North Africa, characterized a bold geometrical figure which stands for belief in living under the protection from supernatural power. Through the understanding of these various meaning, function, symbolism of the design, adorning their body, the current general public use mehndi as not only aesthetic means but also another self expression.

A Study of T-Shirt Graphic Designs Shown in Fashion Collections (패션컬렉션에 나타난 티셔츠의 그래픽디자인에 관한 연구)

  • Kim, Sun-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.7
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    • pp.727-740
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    • 2012
  • This study is for the enhancement and utilization of future graphic design for T-shirts and deals with the expression styles and features of T-shirt graphic designs that appear in modern fashion. A literature examination about graphic design and T-shirts was performed for the research method and the analysis followed 378 pieces of graphic design featured in four major international collections for females from 2001S/S to 2011S/S. The research results from the expression type of T-shirt graphic design in the modern fashion are as follows. Expression in graphic figure accounts for the largest portion of 40.8% that includes illustration or cartoon characters, personal figure or part of the physical body, object in daily life or landscape pictures, animals and plants, and others. Expression given in text with typography or logo accounted for 27.5%, expression combined with letter/text, graphics and geometric figures accounted for 24.3%, geometrical expression accounted for 7.4%; most of which are given in print. Characteristics found in modern fashion graphic design are as follows. First, role of sort of public relations marketing was accompanied with utilization of brand logo or symbol. Second, visual play was shown in a sense of humor with diverse graphic figures and playful texts, witty layout with graphic motives, and a free design formation. Third, it denoted a front burner issue delivering the message for various current events or arguments via the way of texts, slogans, and symbolic pictures. Fourth, it depicted artistry through the self-expressive creation of the designer.

Performance Improvement of Soccer Robot by Vision Calibration and Patch Change in Real Time Environment (실시간 환경에서의 영상조정 및 패치 변경에 의한 축구로봇의 성능개선)

  • Choi, Jeong-Won;Kim, Duk-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.1
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    • pp.156-161
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    • 2009
  • This paper proposes a new method about performance improvement of soccer robots system by the revision of lens distortion most commonly occurred in camera and the revision of position and angle error in robot patch for the realization of robot position. Among the lens distortions, we revise geometrical distortion and apply it to soccer robots system for realtime environment. Patch used in the recognition and the distinction for coordination and direction of robot occurs a position and angle error according to the figure of it. In this paper, we suggest the method of reduction for position and angle error of robot by improved patch and verify its propriety through the experiment.

A Study on the Art-Deco Hair Styles (현대 헤어스타일에 나타난 Art Deco적 특성)

  • Kim, Min-Jung;An, Sung-Kwan;Paik, Sun-Young
    • Journal of the Korean Society of Fashion and Beauty
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    • v.6 no.1
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    • pp.21-27
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    • 2008
  • The purpose of this study was to observe the Art-Deco style art and hair-style. Art-deco design, which was popular in the 20th century, especially in the 1920s and 1930s, actively absorbed new forms, materials, and aesthetic values that come from technological developments and bridged the tradition to new pupblic culture. Art-Deco style art showed and geometrical decoration tendency to meet modem concept and sense. The over all study on back grounds of Art-Deco style and its art works made possible to figure out the summary on formative characteristics of the style such as simplicity, exoticism, vivid colors, and functionalism. These findings suggest that hair styles borrow its characteristics or image from the past style to create new styles. It was found in the development of new hair styles that patterns or geometric motive appearing the Art-D$\acute{e}$eco style are the source of rich design.

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Escape of Lyβfrom Hot and Optically Thick Media

  • Chang, Seok-Jun;Lee, Hee-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.33.2-33.2
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    • 2017
  • Symbiotic stars and quasars show strong far UV resonance doublets including O VI 1032 and 1038, which are known to be major coolants of astrophysical plasma with high temperature T > $10^5K$. We investigate the transfer of $H{\alpha}$ and $Ly{\beta}$ in an emission nebula of temperature T ~ $10^5$, where n=2 population is significant. Line photons of $H{\alpha}$ and $Ly{\beta}$ are transferred in the medium through spatial and frequency diffusion altering their identity according to the branching ratios. We adopt a Monte Carlo technique to describe the transfer of $H{\alpha}$ and $Ly{\beta}$ in an emission nebula with a uniform density and a simple geometrical figure. We find that the temperature of the emission nebula is the major controlling parameter to produce a nonnegligible flux of $Ly{\beta}$. In particular, when T exceeds $10^5K$ the number flux ratio may reach ~ 25% with line center optical depth of a few. We discuss the formation of broad $H{\alpha}$ wings from Raman scattering of $Ly{\beta}$ emergent from a hot emission nebula.

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