• Title/Summary/Keyword: geometrical shapes

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Moment of inertia of liquid in a tank

  • Lee, Gyeong Joong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.1
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    • pp.132-150
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    • 2014
  • In this study, the inertial properties of fully filled liquid in a tank were studied based on the potential theory. The analytic solution was obtained for the rectangular tank, and the numerical solutions using Green's 2nd identity were obtained for other shapes. The inertia of liquid behaves like solid in recti-linear acceleration. But under rotational acceleration, the moment of inertia of liquid becomes small compared to that of solid. The shapes of tank investigated in this study were ellipse, rectangle, hexagon, and octagon with various aspect ratios. The numerical solutions were compared with analytic solution, and an ad hoc semi-analytical approximate formula is proposed herein and this formula gives very good predictions for the moment of inertia of the liquid in a tank of several different geometrical shapes. The results of this study will be useful in analyzing of the motion of LNG/LPG tanker, liquid cargo ship, and damaged ship.

Characteristics of Silk fabrics which was Collected in Temples of the Middle and the Latter Term Chosun Period (조선 중.후기 사찰 견직물에 나타난 특성)

  • 장현주;권영숙
    • Journal of the Korean Society of Costume
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    • v.51 no.8
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    • pp.1-12
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    • 2001
  • An empirical review on silk fabrics of the Chosen period showed that they varied in kind and design according to their uses. Thus the purpose of this study is to classify the fabrics into temple and excavated fabrics according to their uses and collected places and then to examine characteristics of each type. Concerning fabrics collected in temples. satin was most used, followed by twill, tabby, multiply, leno and gauze and clossing fabrics in order. Tabby and silk fabrics used Ju(紬) as their main material. Cho( ) was much more used in fabrics collected in temples than in excavated ones. This indicate that Cho( ), more luxurious than Ju(紬), had divine applications such as covering Buddha s bones of temples. Brilliant, colorful multiply fabrics using goldern and color threads had high effects of ornamenting altar covers, umbrellas, surplices and palanquins. Fabrics held in temples adapted composite designs, in which more than two shapes were used, rather than single ones. Single designs employed plant shapes in most cases. followed by treasures pattern, geometrical, cloud and animal shapes in order. Most composite designs used a combination of animal and plant shapes, followed by plant and geometry, treasures pattern and plant, cloud and animal, and animal, treasures pattern and plant in order. Few excavated fabrics used animal designs while fabrics collected in temples were often designed with shapes of propitious animals such as dragon. Treasures pattern. representing a good omen of Buddhism, was often used sing1y or sometimes compositely with another design.nother design.

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Aerodynamic behavior of supertall buildings with three-fold rotational symmetric plan shapes: A case study

  • Rafizadeh, Hamidreza;Alaghmandan, Matin;Tabasi, Saba Fattahi;Banihashemi, Saeed
    • Wind and Structures
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    • v.34 no.5
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    • pp.407-419
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    • 2022
  • Many factors should be considered by architects and designers for designing a tall building. Wind load is one of these important factors that govern the design of tall building structures and can become a serious challenge when buildings tend to be built very tall and slender. On the other hand, through the initial stages of a design process, choosing the design geometry greatly affects the wind-induced forces on a tall building. With this respect, geometric shapes with 3-fold rotational symmetry are one of the applied plan shapes in tall buildings. This study, therefore, aims to investigate the aerodynamic characteristics of 8 different geometrical shapes using Computational Fluid Dynamics (CFD) by measuring the drag and lift forces. A case study approach was conducted in which different building shape models have the same total gross area and the same height of 300 meters. The simulation was an incompressible transient flow that ran 1700 timesteps (85 seconds on the real-time scale). The results show a great difference between wind-induced force performance of buildings with different plan shapes. Generally, it is stated that the shapes with the same area, but with smaller perimeters, are better choices for reducing the drag force on buildings. Applying the lift force, the results show that the buildings with plan shapes that have rounded corners act better in crosswind flow while, those with sharp corners induce larger forces in the same direction. This study delivers more analytical understanding of building shapes and their behavior against the wind force through the parametric modelling.

An Experimental Study on the Free Vibration of Composite Plates with Various Shapes (다양한 형상을 갖는 복합재료 판의 자유진동에 대한 실험적 연구)

  • 이영신;최명환
    • Composites Research
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    • v.12 no.1
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    • pp.47-58
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    • 1999
  • This paper describes the results of experiments to analyze the free vibration of the laminated composite and hybrid composite plates with various shapes and boundary conditions. The materials of specimens were the carbon fiber reinforced plastic (CFRP), the glass fiber reinforced plastic (GFRP), the GFRP-Aluminum hybrid composite and the CFRP-CFRP hybrid composite. The natural frequencies and nodal patterns of plates with various shapes were experimentally obtained by impact exciting test using an impact hammer and an accelerometer. The experimental results were presented with normalized frequency parameters. The effects of composite material properties, fiber orientation angles, various geometrical shapes and boundary conditions on the vibration characteristics of composite plates were evaluated. To compare and verify these experimental results, the finite element analysis was carried out, and was well agreed with experimental results.

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The Aesthetic Values of Formalism Art to Wear (형식주의 예술의상의 미적 가치)

  • 서승미;양숙희
    • The Research Journal of the Costume Culture
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    • v.11 no.1
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    • pp.118-134
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    • 2003
  • The first purpose of this study is to take a better look it the background of Formalism art in the cultural society and to examine the aesthetic value of the formative arts of formalism architecture that are ail basically founded upon the study of Formalism. Secondly, it analyzes the aesthetic value of Formalism Art to Wear, Which can be explained as a mixture of art and fashion, by investigate to the features of art history. The results are as follows; First, Formalism Art to Wear of Simultaneity does not represent continuance but simultaneous. In other words. inside the same time and place of dimension, events art visualized without transformation. Secondly, formalism Art to Wear of Geometrical Aesthetics deals with a purely genuine atmosphere that pursues absolute perfection, composed abstract of geometrical shapes. Thirdly, Fomarlism Art to Wear of Deformation breaks analysis from balance and symmetry showing extreme transformation nil new vitality. Fourthly, Formalism Art to Wear of Space Extension experiments with post-corporeality. Post-corporeality centers the human body extension that is open to various boundaries of implosion and electronic technologies, providing us with a new Cyborg of the digital body.

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A Note on the Hull Form Variational Methods (선형변환 방법에 대한 소고)

  • 이춘주;윤현세;유재문
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.1
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    • pp.63-68
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    • 2003
  • Systematic geometrical variation method of hull forms, such as "1 -Cp", "Swinging" and "Lackenby" are widely used in the early stage of a new design from those of a similar parent ship, which shows a better performance through the model test and/or sea trials. This method is simple and easy to modify original hull forms without changing the main characteristics. The shape of the prismatic curie can be easily varied by these methods, however, the frame line shape in the body plan can′t be generated easily, when the section shapes are complicated or have discontinuities or the mismatch of the body plan and the stem and stern profiles. To overcome this drawback of the hull form variations, a simple and useful method has been proposed in the present study.

A Study on Feed Rate Optimization in the Ball End-milling Process Regarding of Tool Path and Workpiece Shape (볼 엔드밀을 이용한 금형가공에 있어서 이송 속도 최적화에 대한 연구)

  • 김성윤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.04a
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    • pp.102-106
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    • 1996
  • In the ball end-milling process of a 3-dimensional mold, it is important to select cutting conditions and tool path considering the geometrical shape of a workpiece to reduce machining time. In this study, experiments were performed to decide allowable feed rate not breaking stability of system for different geometrical shapes. It was found that downcut is more stable than upcutting in machining side wall and downward is preferable to upward in inclined part depending on the angle of the inclination and depth of cut.

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Sound Propagation over Multiple Wedges and Barriers

  • Kim, Hyun-Sil;Kim, Jae-Sueng;Kang, Hyun-Ju;Kim, Bong-Ki;Kim, Sang-Ryul
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.2E
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    • pp.44-50
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    • 2004
  • A theoretical formula that is based on the geometrical theory of diffraction (GTD) is proposed for computing sound diffraction by multiple wedges, barriers, and polygonal-like shapes. The formula can treat both convex and concave edges, where edges mayor may not be inter-connected. Comparisons of theoretical predictions with other results done by the BEM or experiments for scaled model confirm the accuracy of the present formula. Numerical examples such as double wedges and doubly inclined barrier show that when there exist several diffraction paths for given source and receiver positions, the insertion loss is dominated by the diffraction associated with the shortest propagation path.

Laser Forming of Sheet Metal by Geometrical Information (기하학적 정보를 이용한 이중곡률 형상의 레이저 성형)

  • Kim, Ji-Tae;Na, Seok-Ju
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.91-93
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    • 2005
  • Forming sheet metal by laser-induced thermal stresses (laser forming) has been extensively studied, and the research has focused on two-dimensional geometries using a multi-pass straight line scan. Recently there came out some useful studies or three-dimensional laser forming which is applied to doubly curved shapes. The task of 3D laser forming sheet metal is to determine a set of process parameters such as laser scanning paths, laser power and scanning speed that will make a given shape. New method for laser forming of a doubly curved surface by using geometrical information was proposed and verified by experiments. This method shows good performance in the sense of calculation time and accuracy compared to the inherent strain method.

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Fashion Design of Disassembly and Assembly Based on Geometrical Analysis of the Body Figure (인체 형태의 기하학적 분석에 기반한 분해와 조합의 패션디자인 개발)

  • Kyung-Jin, Lee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.26 no.1
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    • pp.61-76
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    • 2024
  • The purpose of this study is the development of an experimental design that aims to implement three-dimensional fashion design by observing the human body, extracting and combining geometric shapes and forms, and focusing on attempts to decompose the geometry of the human body in art history. Considering the characteristics of fashion design, which inevitably reflect human images visually, this study considered works by deriving geometric shapes and forms of the human body and focusing on decomposition and combination to apply them to fashion design. The results obtained through the development of fashion design through decomposition and combination based on geometric human body analysis are as follows. First, geometric analysis of the human body as an object of expression continues from the history of Cubism to modern fashion design. Second, the geometric shapes of the human body that appear in contemporary fashion design maximize visual effects through three-dimensional composition, emphasizing simplicity while showing originality through various expressions. Third, when exploring the geometric shapes of a moving human body, it was possible to extract a wide variety of shapes and forms through drawing and simplifying the human body's movements. Fourth, the formative method of fashion design was introduced and used for the aesthetic combination of objects for fashion design through decomposition and combination. This study was able to show unique and diverse combinations of visually concise and ordered geometric shapes in the expression of fashion design by decomposing and combining them. The significance of these geometric forms is that they can diversify formative informativeness in the expression of fashion design with modern compositional beauty.