• Water for future
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• v.28 no.2
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• pp.115-124
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• 1995

A GIS is capable of extracting various hydrological factors from DEM(digital elevation model). One of important tasks for hydrological analysis is the division of watershed. It can be an essential factor among various geometric characteristics of watershed. In this study, watershed itself and other geometric factors of watershed are extracted from DEM by using GIS technique. The manual process of tasks to obtain geometric characteristics of watershed is automated by using the functions of ARC/INFO software as GIS package. Scanned data was used for this study and it is converted to DEM data. Various forms of representation of spatial data are handled in main module and GRID module of ARC/INFO. GRID module is used on a stream in order to define watershed boundary, so it would be possible to obtain the watersheds. Also, a flow direction, stream networks and orders are generated. The results show that GIS can aid watershed management and research and surveillance. Also the geometric characteristics parameters of watershed can be quantified with ease using GIS technique and the hardsome process can be automated.

• Journal of KSNVE
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• v.6 no.6
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• pp.735-747
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• 1996

In this paper, buckling reliability analyses of stiffened cylinder with random initial geometric imperfection under axial impact load are performed by the combined response surface method. The effect of random geometric imperfection on the failure probability and reliability is recognized quantitatively. Buckling reliability decreases with the increase of mean value, cov of initial geometric imperfection under the same external load. Buckling probability under impact load is greater than those under static load with the same condition. From the probabilistic characteristics of imapct buckling load, relation between reliability index and safety parameter can be obtained in addition to the relation between load and reliability index. And those results can be used to determine the range of required safety parameter and acceptable imperfaction.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.3
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• pp.258-262
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• 2010

This paper describes a watermarking system that has the robust characteristics against the geometric attacks of resizing and the bitrate varying attacks. While the existing watermark methods of marking on AC in DCT coefficients are weak against the geometric attacks, the methods of tiny increasing the DC in DCT coefficients and the system implementations are suggested in this paper. We measure the differences between the original images and the watermarked images and the detecting rate from the geometric and bitrate attacked images. Results of experiments show that our method is robust against that attacks.

• The Research Journal of the Costume Culture
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• v.29 no.3
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• pp.361-373
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• 2021

The purpose of this study is to contribute to the role of lines in creative design development by analyzing the expression types and aesthetic characteristics of modern fashion using geometric formativeness of symmography. A literature study was conducted of works since 2009 to examine the general consideration of lines together with analysis of the concept and characteristics of symmography in the formative arts field, and to analyze the expression types and aesthetic characteristics of modern fashion design using the formativeness of symmography. The infinite sense of formativeness and original expression of symmography are used in formative arts such as space design, installation art, and industrial design. Expression types of modern fashion design using geometric formativeness of symmography can be classified into the following three types: two-dimensional graphic pattern, relief surface, and three-dimensional spatial. First, the two-dimensional graphic pattern type forms an optical pattern, providing individuality and visual interest to the textile design. Second, the relief surface type expresses the plane in various ways, so that the thickness changes according to how lines overlap. Third, the three-dimensional spatial type expands the boundaries of clothing and creates a fantastic spatial beauty. Next, the aesthetic formativeness of fashion design using symmography can be classified into repetitive rhythmicity, geometric self-similarity, and optical spatiality. Symmography enables a myriad of geometric patterns to be developed depending on material, color, and the designer's imagination, and helps inspire a variety of designs in fashion that sculpt a three-dimensional human body.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.71-84
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• 2000

In this study, design characteristics of Village Parks in Seoul are investigated through an analysis of structuring themes expressed in spatial design. The goals and objectives of this study are: to emphasize the significance of design themes; and to demonstrate an approach to the design of landscapes through an analysis of structuring themes. For conducting this study, geometric forms and naturalistic forms were examined first. That is, the following 15 structuring themes were examined, as guiding themes: the 90$^{\circ}$rectangular theme; the 45$^{\circ}$/90$^{\circ}$angular theme; the 30$^{\circ}$/60$^{\circ}$ angular theme; circles on circle; concentric circles and radii; arcs and tangents; circle segments; the ellipse; the spiral; the meander; the free ellipse and scallops; the free spiral; the irregular polygon; the organic edge; and clustering and fragmentation. Forty five Village Parks in Seoul, built between 1996 and 1997, were analyzed through these 15 structuring themes. An analysis of Village Parks was conducted by the following two categories: land shape and structuring themes; and design directions and structuring themes. The research results are as follows; 1) Geometric forms are more frequently applied than naturalistic forms. 2) Regardless of land shape, geometric forms derived from simple primary shapes, the square and the circle, are frequently used. And the meander and the irregular polygon among naturalistic forms are frequently used. 3) Regarding design directions and structuring themes, design concepts, symbolic meanings and spatial forms are, to some degree, integrated. 4) The spiral is not applied among geometric forms. And the meander and the irregular polygon, as naturalistic forms, are frequently utilized. Research findings obtained from this study could be used in the designing of future Village Parks. For a profound study, future, research is needed in two-dimensional plans and three-dimensional elements of Village Parks.

• The Research Journal of the Costume Culture
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• v.10 no.6
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• pp.763-780
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• 2002

The aim of this research is to analyze Vionnet´s geometric features, which can be regarded as the key formative beauty among the external characteristics of her works. and to thereby establish the theory that her works emitted a time-transcending life force because they were patterns designed based on a geometrical frame of mind. To prove such argument, studies to understand the basic geometrical aspects appearing in her works will be made by taking a look at the general features of geometry, viewing Vionnet´s philosophy for designing, and examining the geometric cutting methods. The period covered in this paper will center mainly on dresses Vionnet made from her very active days in the fashion sector, 1919. till when she retired from the fashion industry, around 1939. What's outstanding about Vionnet´s geometric principle expressed in her works is the unique cutting method that acknowledges the silhouette of the human body as a cubic or three-dimensions concept, through insight of the human body, the mechanics of the materials, and geometry. Vionnet introduced a simple and elegant design by combining geometric figure cuts, such as rectan히es. quadrants, and triangles. Moreover, she created a new sewing structure that plans everything about the materials to the tiniest detail, resulting in producing a softer style With this, Vionnet showed the geometrical correlation can bring about harmony and the beauty of ideal proportion, forming the source of eternal beauty. As discussed so fu, the geometrical characteristics appearing in Vionnet´s works are marked such as spirals, zig-zag lines, asymmetries. panels, gradation, golden proportion, and the mobius-band.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1097-1107
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• 2020

A methodology has been proposed to understand the spatiotemporal changes of the river topography through the longitudinal change of the geometric characteristics of the cross-sections and the properties related thereto. Three-dimensional spatial information of the riverbed was obtained through the detailed bathymetry survey using an acoustic echo sounder for the reach from Gumi Weir to Chilgok Weir in the Nakdong river. Geometric informations for the reference sections were extracted using the acquired bathymetry survey data. By comparing the geometric properties for the reference sections, it was possible to catch the topographic characteristics and its changes over a reach of the channel. Through comparison with past survey data, it was also possible to quantitatively grasp the amount of change in cross-sectional area and volumetric change of riverbed. It is expected that a quantitative evaluation of river topography changes will be possible by applying the method proposed in this study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.913-917
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• 1994

A collision-free geometric path for industrial articulated robot is searched among polyhedral obstacles considering kinematic charcteristics. Then minimum-time control of the geometric path is studied considering dynamic characteristics. The algorithm is simulated on PC for maximum speed, moving time and so forth.

• The Mathematical Education
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• v.46 no.3
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• pp.245-261
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• 2007

This paper deals with the possible problems which may arise when students learn the names of elementary geometric figures in the languages of Korean, Chinese, English. The names of some simple geometric figures in these languages are analyzed, and a specially designed test was administered to some grade eight students from the three language groups to explore the possible influence of the characteristics of the languages on students' capability in identifying the figures, the way students define the figures, and students' understanding of the inclusive relationship among figures. It was found that the usage of the terms to describe geometric figures may indeed have affected students' understanding of the figures. The names of geometric figures borrowed from those of everyday life objects may cause students to fix on some attributes of the objects which may not be consistent with the definition of the figures. Even when the names of the geometric figures depict the features of the figures, the words used in the naming of the figures may still affect students' understanding of the inclusive relations. If there is discrepancy between the definition of a geometric figure and the features that the name depicts, it may affect students' understanding of the definition of the figure, and if there is inconsistency in the classification of figures, it may affect students' understanding of the inclusive relationship involving those figures. Some implications of the study are then discussed.

• KSTLE International Journal
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• v.2 no.1
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• pp.46-54
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• 2001

The herringbone groove journal bearing (HGJB) has chevron type grooves on stationary or rotating member of the bearing so that they pump the lubricant inward the grooves when journal rotates. As a result, the pressure is generated around the journal so that the radial stiffness and dynamic stability are improved comparing to the plain journal bearing (PJB) when the bearing operates near the concentric condition. The narrow groove theory, conventionally adopted to simulate the concentric operation of HGJB, is limited to the infinite number of grooves. A numerical study of air-lubricated HGJB is presented for the finite number of grooves. The compressible isothermal Reynolds equation is solved by using Finite Element Method together with the Newton-Raphson iterative procedure and perturbation method. The solutions render the static and dynamic performances of HGJB. Comparison of present results with a PJB validates previously published finite difference solution. The HGJB's geometric parameters influence its static and dynamic characteristics. The optimum geometric parameters are presented for the air-lubricated HGJB in particular conditions.