• Title/Summary/Keyword: characteristic curves

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Computation of Section Curves, Reflection Characteristic Lines, and Asymptotic Curves for Visualization (가시화를 위한 단면곡선, 반사성질선, 점근선 생성 기법)

  • 남종호
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.4
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    • pp.262-269
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    • 2003
  • An approach to compute characteristic curves such as section curves, reflection characteristic lines, and asymptotic curves on a surface is introduced. Each problem is formulated as a surface-plane inter-section problem. A single-valued function that represents the characteristics of a problem constructs a property surface on parametric space. Using a contouring algorithm, the property surface is intersected with a horizontal plane. The solution of the intersection yields a series of points which are mapped into object space to become characteristic curves. The approach proposed in this paper eliminates the use of traditional searching methods or non-linear differential equation solvers. Since the contouring algorithm has been known to be very robust and rapid, most of the problems are solved efficiently in realtime for the purpose of visualization. This approach can be extended to any geometric problem, if used with an appropriate formulation.

Experimental Study for Soil-Water Characteristic Curves of Unsaturated Soil (불포화토의 흙-수분 특성곡선에 관한 실험적 고찰)

  • 송창섭;김명환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.6
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    • pp.153-161
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    • 2003
  • The purpose of this paper is to investigate the soil-water characteristic curves for an unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soils taken from different sites of Korea, using modified pressure plate apparatus. Form the test results, the water contents, degree of saturation and volumetric water contents were analyzed with the suction. And the soil-water characteristic curves of unsaturated soil were drawn from the test results for various factors. The characteristic curves drawn with water content vs matric suction were classified certainly the difference in wet side but were not classified in dry side. The characteristic curves drawn with degree of saturation vs matric suction for unsaturated soil were shown the opposite inclination as compared with the former curve. But the characteristic curve with volumetric water content vs matric suction was described suitably not only in wet side condition but also in dry side. And it was found that the volumetric water contents of loose soil was high at the initial condition but that of dense soil was high at final condition (dry side).

A Study on Soil-Water Characteristic Curves of Reclaimed Soil and Weathered Granite Soil (준설매립토 및 화강풍화토의 흙-수분 특성곡선에 관한 연구)

  • 신은철;이학주;김환준
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.743-750
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    • 2002
  • Unsaturated soil has a possibility to induce a negative pore water pressure. Until now, saturated soil is mainly focused on the research of soil mechanics. Recently, soil mechanics is researched on two major parts such as saturated and unsaturated soil mechanics. Negative pore water pressure has a non-linear relationship with the water content changes. Soil-water characteristic curves of soil in Korea are not determined. There is no proper characteristic value such as air-entry value and residual water content. In this study, the characteristic curves of reclaimed soil, sand, and weathered granite soil were determined by laboratory tests. Air-entry value and residual water content were determined by fitting methods. Soil-water characteristic curves were estimated based on the particle-size distribution and compared with the laboratory test results. The results of soil-water characteristic curves estimation indicated that Fredlund and Wilson's model is excellent for sand and weathered granite soil. Arya and Paris's model is excellent for reclaimed soil.

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INTEGRAL CURVES OF THE CHARACTERISTIC VECTOR FIELD ON CR-SUBMANIFOLDS OF MAXIMAL CR-DIMENSION

  • Kim, Hyang Sook;Pak, Jin Suk
    • Communications of the Korean Mathematical Society
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    • v.32 no.1
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    • pp.107-118
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    • 2017
  • In this paper we study CR-submanifolds of maximal CR-dimension by investigating extrinsic behaviors of integral curves of characteristic vector field on them. Also we consider the notion of ruled CR-submanifold of maximal CR-dimension which is a generalization of that of ruled real hypersurface and find some characterizations of ruled CR-submanifold of maximal CR-dimension concerning extrinsic shapes of integral curves of the characteristic vector field and those of CR-Frenet curves.

ISOMORPHISM CLASSES OF GENUS-3 POINTED TRIGONAL CURVES OVER FINITE FIELDS OF CHARACTERISTIC 2

  • Kang, Pyung-Lyun;Sun, Sun-Mi
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.5
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    • pp.917-930
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    • 2009
  • We find all distinct representatives of isomorphism classes of genus-3 pointed trigonal curves and compute the number of isomorphism classes of a special class of genus-3 pointed trigonal curves including that of Picard curves over a finite field F of characteristic 2.

A Study on Reverse Engineering and 5-axis NC Machining of Impeller (임펠러의 역공학과 5축가공에 관한 연구)

  • 장동규;신재광;홍성균;이희관;양균의
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.6
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    • pp.60-68
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    • 2004
  • This paper presents a method fur impeller modeling and 5-axis machining by the reverse engineering. The impeller is composed of pressure surface, suction surface and leading edge, and so on. The surfaces can be modeled by using the characteristic curves such as hub curves, shroud curves and fillet curves. The characteristic curves are extracted from the scanned data and the inspection is performed between the surfaces generated by using the characteristic curves and the scanned data. Then, An impeller is machined by 5-axis mainlining and post-processing with inverse kinematic solution.

Reverse Engineering and 5-axis NC machining of impeller (임펠러의 역공학과 5축가공)

  • 신재광;홍성균;장동규;이희관;양균의
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1795-1798
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    • 2003
  • This paper presents a method for impeller modeling by the reverse engineering and the 5-axis machining. The impeller is composed of pressure surface, suction surface and leading edge, and so on. The impeller is modeled by using the characteristic curves of impeller such as hub curves, shroud curves and leading edge. The characteristic curves are extracted from the scanned data. The hub curves and shroud curves are generated by intersection between blade surface and hub boundary and shroud boundary. respectively. A sample impeller machining is performed by tool path plan and post-processing with inverse kinematic solution.

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Soil-Water Characteristic Curves for an Unsaturated Soil (불포화토의 흙-수분 특성곡선)

  • Song, Chang-Seob;Lim, Seong-Yoon;Kim, Myeong-Hwan
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.179-182
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    • 2003
  • The purpose of this paper was to investigate the soil-water characteristic curves for unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soil which is located in Korea, used the modified pressure plate apparatus. From the test results, the water contents, degree of saturation and volumetric water contents was analyzed with the suction. And was drawn the soil-water characteristic curves was drain from the test results for various factors.

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Receiver Operating Characteristic (ROC) Curves Using Neural Network in Classification

  • Lee, Jea-Young;Lee, Yong-Won
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.911-920
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    • 2004
  • We try receiver operating characteristic(ROC) curves by neural networks of logistic function. The models are shown to arise from model classification for normal (diseased) and abnormal (nondiseased) groups in medical research. A few goodness-of-fit test statistics using normality curves are discussed and the performances using neural networks of logistic function are conducted.

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A Study about Hull Form Generation of High-Speed Coastal Fishing Vessel using Irrational Function and Hull Form Characteristic Curves (무리함수와 선형 특성 곡선들을 이용한 고속연안어선의 선형생성에 관한 연구)

  • Kim, Soo Young;Kim, Hyun Cheol;Baek, Jun Myung;Lee, Choong Ryoul
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.3
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    • pp.96-103
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    • 1997
  • This paper presents a mathematical method that represents efficiently high-speed coastal fishing vessel. That is, it represents the numerical hull by using irrational function and hull form characteristic curves, which define a hull form under design conditions. Then it suggests a process that hull form characteristic curves are represented with NURBS and hull form is varied.

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