• Title/Summary/Keyword: New Surface Shape

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Study on the Design Method for the Train Nose Shape Using the Configuration Function (형상함수를 이용한 열차 전두부 설계기법 연구)

  • Ku, Yo-Cheon;Rho, Joo-Hyun;Yun, Su-Hwan;Kwak, Min-Ho;Lee, Dong-Ho
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2218-2223
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    • 2008
  • A nose shape is strongly related with the aerodynamic performances of train. Therefore shape definition and aerodynamic performance analysis are important for train nose shape design. In this study, a new design method was suggested for train nose shape design by configuration function. To this end, the nose shape was classified by box type and each box shape is defined. After that the 3-D shape of train was defined as several mathematical functions by combination of each box shape. Also it was shown that the wind shield of driver's seat and complex curves of surface can be expressed using superposition of functions. This methodology can be used for grid generation of numerical analysis, and applied to aerodynamic optimization design of nose shape.

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3D Shape Descriptor Based on Surface Distance (표면 거리 기반 3차원 형태 기술자)

  • Park Hyun;Kim Jea-Hyup;Moon Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.3 s.309
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    • pp.59-66
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    • 2006
  • In this thesis, we propose a new 3D shape descriptor. The proposed descriptor measures geometric characteristics by using the shortest path on surfaces. The descriptor is robust against a change of local posture. We measure the geometric characteristics of 3D object through a new shape function to construct the shape distribution. The proposed shape function is the shortest path shape function. The shape function measures the distance between two points on the surface of a 3D object. We evaluate the performance of the proposed method, compared with the previous method. The precision of retrievals improved by 23% in the case of articulated objects and is improved by 12% in the case of general objects.

Two New Species of the Genus Burmoniscus (Isopoda, Oniscidea, Philosciidae) from Ko Samui and Ko Pha Ngan, Thailand (泰國 코사무이와 코파응안의 Burmoniscus屬 陸棲 等脚類(Isopoda, Oniscidea, Philosciidae) 2新種)

  • Jeon, Dae-Soo;Kwon, Do-Heon
    • Animal Systematics, Evolution and Diversity
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    • v.17 no.1
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    • pp.145-153
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    • 2001
  • Two new species of the genus Burmoniscus, B. siamenis and B. phanganensis, are described from Ko Samui and Ko Pha Ngan, Thailand. B. siamenis is similar to B. mauritiensis (Taiti and Ferrara, 1983) in color pattern and the shape of telson, but distinguished by the shape of pereonite 7 with obtuse postero-lateral angle and the peculiar shape of male pleopod 2 endopod with truncated apex. B. phanganensis is close to B. ocellatus Verhoeff, 1928) in the shape of pereonite 7 and telson, but easily distinguished by the peculiar shape of male pleopod 1 endopod with two rows of denticles on caudal surface.

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AUTOMATIC BUILDING EXTRACTION BASED ON MULTI-SOURCE DATA FUSION

  • Lu, Yi Hui;Trinder, John
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.248-250
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    • 2003
  • An automatic approach and strategy for extracting building information from aerial images using combined image analysis and interpretation techniques is described in this paper. A dense DSM is obtained by stereo image matching. Multi-band classification, DSM, texture segmentation and Normalised Difference Vegetation Index (NDVI) are used to reveal building interest areas. Then, based on the derived approximate building areas, a shape modelling algorithm based on the level set formulation of curve and surface motion has been used to precisely delineate the building boundaries. Data fusion, based on the Dempster-Shafer technique, is used to interpret simultaneously knowledge from several data sources of the same region, to find the intersection of propositions on extracted information derived from several datasets, together with their associated probabilities. A number of test areas, which include buildings with different sizes, shape and roof colour have been investigated. The tests are encouraging and demonstrate that the system is effective for building extraction, and the determination of more accurate elevations of the terrain surface.

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Production Method of FRP Boat Using Developable Surface without a Mould (외판 전개를 응용한 무형틀 FRP선박 건조방법)

  • Yang, Ji-Man;Ha, Yun-Sok;Kim, Hyo-Chul
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.5 s.143
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    • pp.506-515
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    • 2005
  • Novel ships are commonly required iterative hull form modifications until she get reputation for new marine environment. Small FRP boats are manufactured in a identical shape with a mould. It implies that every modification step requires great time and expense which makes it difficult to improve the hull form promptly. Domestic hull form of small fishing boat of force has been evolved from the traditional hull form of developable shape. Utilizing this typical developable characteristics of small boats, ,New mouldless production method for FRP boat has been suggested and it is confirmed that the method is recommendable for a petty order of hull in evolving period of hull form development.

A Study on the Characteristics of Work Roll Texturing for Temper Mill

  • Kim, Soon Kyung;Kim, Moon Kyung;Shahajwalla, Veena;Chung, Uoo Chang
    • KSTLE International Journal
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    • v.2 no.1
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    • pp.80-84
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    • 2001
  • The purpose of this paper is to show the result from the study to improve the formability and appearance which is important in the cold rolled strip, the coated strip and prepainted strip. Furthermore, to give appropriate surface roughness, shape of work roll for temper mill is also important. The strip has a greater peak counts and homogeneous roughness. This makes the prepainted surface smooth and consistent in appearance with good image clarity. Therefore, the surface roughness of the work roll is very important. The reason that surface roughness of the work roll is transferred to the strip surface is the rolling farce and tension at the temper rolling or cold rolling. This study is classified in order to get an accurate and homogeneous roughness. There are few papers published in this field, because its importance is not known and the proper operation of the machine is not generally well known. This paper investigates the correlation between strip surface roughness and the surface of the work roll. After studying the surface roughness and shape according to the texturing method for roll surfaces at temper rolling, the findings were as follows. Irregular surface roughness can be compensated with several paint coatings, but this also makes the quality deteriorate and manufacturing costs go up.

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A New Species of the Genus Caminus (Astroporida: Geodiidae) from Korea

  • Shim, Eun-Jung;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.3
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    • pp.208-211
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    • 2012
  • Caminus jejuensis n. sp was collected from depth of 20 m at Geomeunyeo, Seogwipo, Jejudo Island by a SCUBA diving from April 2004 to December 2008. This new species is similar to C. chinensis from China in the composition of spicules except for the spherasters and they differ in spicule size and growth form. This species has longer orthotriaenes and spherules, smaller sterrasters and oxyasters than those of C. chinensis. This species also has many spherasters in choanosome, but C. chinensis lacks. Morever, the new species is a massive shape with wrinkles, whereas C. chinensis is a club shape with smooth surface. Description and figures of the new species are provided.

A Study on the Preparation of Oil Absorbent Using Waste Polyurethane (폐폴리우레탄을 이용한 오일 흡수제의 제조)

  • Kim, Hyung-Soon
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.2
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    • pp.73-80
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    • 2007
  • The preparation of oil absorbent using waste polyurethane was studied. And the effects of shape, size, and contents of waste polyurethane foam was investigated. The waste foam was treated in shape of powder, cube and bar type generated from rigid sandwich panel process. The tests for flexural strength, combustibility, and water absorptivity were carried out to investigate the mechanical and physical properties of the recycled foams. And the cell microstructure was evaluated through Scanning Electron Micrograph. The recycled foam containing powder-shaped underfilled and showed poor properties that was generated through reactivity of the resins and increasing of slurry viscosity. For the recycled foam with the cube and bar-shaped, the underfilling was caused by interference between the waste PUFs and increasing surface areas of PUF. Low cell density, non-uniformity of cell shape and size, and low adhesion of the boundary surface (new/recycled) was showed as a result of the poor properties. Considering underfilling and the properties of PUF (new/recycled), maximum recycle contents were less than 20 wt% for the powder and above 40 wt% for the cube and bar.

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Shape Reconstruction from Unorganized Cloud of Points using Adaptive Domain Decomposition Method (적응적 영역분할법을 이용한 임의의 점군으로부터의 형상 재구성)

  • Yoo Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.8 s.185
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    • pp.89-99
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    • 2006
  • In this paper a new shape reconstruction method that allows us to construct surface models from very large sets of points is presented. In this method the global domain of interest is divided into smaller domains where the problem can be solved locally. These local solutions of subdivided domains are blended together according to weighting coefficients to obtain a global solution using partition of unity function. The suggested approach gives us considerable flexibility in the choice of local shape functions which depend on the local shape complexity and desired accuracy. At each domain, a quadratic polynomial function is created that fits the points in the domain. If the approximation is not accurate enough, other higher order functions including cubic polynomial function and RBF(Radial Basis Function) are used. This adaptive selection of local shape functions offers robust and efficient solution to a great variety of shape reconstruction problems.

Obtaining 3-dimensional shape of hybrid reflectance surfaces using indirect diffuse illumination (간접 확산 조명을 이용한 혼성반사 표면의 3차원 형상 취득)

  • 김태은;안호근;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.301-312
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    • 1996
  • A new approach is presented for recovering the 3-D shape from shading image. Photometric Stereo Method (PSM) is generally based on the direct illumination. In this paper, the reflectance function is derived by introduceing the indirect diffuse illumination in PSM and then applied to hybrid reflectance model which consists fo two components; the Lambertian reflectance and the speclar reflectance. Under the hybrid reflectance model and the indirect diffuse illumination circumstances, the 3-D shape of object can be recovered from the suface normal vector extracted from the surface roughness, the surface reflectance ratio, and the intensity value of a pixel. This method is rapid because of using the reference table and simplifies the restriction condition about the reflectance function existing in prior studies. The recovery efficiency in our method is better than that in prior studies. Also, this method is applied to various types of surfaces by defining general reflectance function.

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