• Title/Summary/Keyword: 지오메트리

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Morphable Model to Interpolate Difference between Number of Pixels and Number of Vertices (픽셀 수와 정점들 간의 차이를 보완하는 Morphable 모델)

  • Ko, Bang-Hyun;Moon, Hyeon-Joon;Kim, Yong-Guk;Moon, Seung-Bin;Lee, Jong-Weon
    • The Journal of the Korea Contents Association
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    • v.7 no.3
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    • pp.1-8
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    • 2007
  • The images, which were acquired from various systems such as CCTV and Robot, include many human faces. Because of a rapid increase in visual data, we cannot process these manually; rather we need to do these automatically. Furthermore, companies require automatic security systems to protect their new technology. There are various options available to us, including face recognition, iris recognition and fingerprint recognition. Face recognition is preferable since it does not require direct contact. However, the standard 2-Dimensional method is limited, so Morphable Models may be recommended as an alternative. The original morphable model, made by MPI, contains a large quantity of data such as texture and geometry data. This paper presents a Geometrix-based morphable model designed to reduce this data capacity.

LES for Turbulent Duct Flow with Mass injection (덕트내부에서 질량분사가 있는 난류유동의 LES 해석)

  • Kim, Bo-Hoon;Na, Yang;Lee, Chang-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.210-213
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    • 2010
  • Recent experimental data shows that the noticeable feature of irregular roughened spots on the fuel surface occurs during the combustion test. The generation of these unexpected patterns is likely to be resulted from the disturbed boundary layer due caused by wall blowing which is intended to simulate the process of fuel vaporization. LES without chemical reaction was conducted to investigate the flow characteristics at the near-fuel surface and the behavior of turbulent structures which is evolved by the wall blowing at the Reynolds number of 23,000. Cylindrical geometry was considered to get the most reality of the calculation results because real hybrid rocket motor is circular grain configuration. It was shown that the wall blowing pushed turbulent structures upwards making them tilted and this skewed displacement, in effect, left the foot prints of the structures on the surface. This change of kinematics may explain the formation of irregular isolated spots on the fuel surface observed in the experiment.

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Optimum Design of Pitch Reducer for Wind Turbine Using Genetic Algorithm (유전 알고리즘을 이용한 풍력발전기용 피치감속기의 최적 설계)

  • Kim, Jeong Gil;Park, Young Jun;Lee, Geun Ho;Nam, Yong Yun;Yang, Woo Yeoul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.2
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    • pp.185-192
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    • 2014
  • Planetary gear design is complex because it involves a combination of discrete variables such as module, integer variables such as the number of teeth, and continuous variables such as face width and aspect ratio. Thus, an optimum design technique is needed. In this study, we applied a genetic algorithm to the design optimization of a planetary gear. In this algorithm, tooth root strength and surface durability are assessed with fundamental variables such as the number of teeth, module, pressure angle, and face width. With the help of this technique, gear designers could reduce trial and error in the initial design stages, thus cutting the time required for planetary gear design.

An Epipolar Rectification for Object Segmentation (객체분할을 위한 에피폴라 Rectification)

  • Jeong, Seung-Do;Kang, Sung-Suk;CHo, Jung-Won;Choi, Byung-Uk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1C
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    • pp.83-91
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    • 2004
  • An epipolar rectification is the process of transforming the epipolar geometry of a pair of images into a canonical form. This is accomplished by applying a homography to each image that maps the epipole to a predetermined point. In this process, rectified images transformed by homographies must be satisfied with the epipolar constraint. These homographies are not unique, however, we find out homographies that are suited to system's purpose by means of an additive constraint. Since the rectified image pair be a stereo image pair, we are able to find the disparity efficiently. Therefore, we are able to estimate the three-dimensional information of objects within an image and apply this information to object segmentation. This paper proposes a rectification method for object segmentation and applies the rectification result to the object segmentation. Using color and relative continuity of disparity for the object segmentation, the drawbacks of previous segmentation method, which are that the object is segmented to several region because of having different color information or another object is merged into one because of having similar color information, are complemented. Experimental result shows that the disparity of result image of proposed rectification method have continuity about unique object. Therefore we have confirmed that our rectification method is suitable to the object segmentation.

A Study on the Difference of Geometrical Modeling in the Calculation of Shielding and Activation Using Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 차폐 및 방사화 계산에서 기하학적 모델링의 차이에 따른 결과 연구)

  • Heo, Seunguk;Song, Yongkeun;Cho, Gyuseok;Han, Moojae;Park, Jikoon
    • Journal of the Korean Society of Radiology
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    • v.11 no.6
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    • pp.429-435
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    • 2017
  • In order to increase the therapeutic effect of radiation, there has been an increase in the use of conventional photon therapy. The intensive care unit should pay more attention to the radiation safety evaluation due to the higher energy and the larger facility compared to the existing Photon treatment. These radiation safety evaluations are mainly performed by using Monte Carlo simulation, and the first thing to be done is geometric modeling. The Heavy-ion treatment facility uses synchrotron as the accelerating device, which is difficult to precisely model geometrically and is mostly modeled briefly. This study investigated the effect of simplification and precise implementation of Dipole magnet among the components of synchrotron acceleration device on the radiation safety evaluation. The results show that the simplified geometric model is overestimated with the precisely implemented geometric model. Therefore, it is considered that the radiological safety evaluation results in more reliable results of the precise geometric modeling.

Production Technology for Multi-face Convergence Performance (Multi-face Convergence 공연을 위한 제작 기술)

  • You, Mi;Son, Tae-Woong;Kim, Sang-Il
    • Journal of Broadcast Engineering
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    • v.25 no.4
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    • pp.475-486
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    • 2020
  • This paper is a thesis on media art technology for high-tech performances and exhibitions. After creating an interactive stroke in VR, it is projected in real time through a media facade technique. Among our traditional dramas emphasizing linear movements, movements were extracted from the Bongsan mask dance, and the movements of the lines were used in a media art performance called 'Multi-face Convergence'. When motion data enters the virtual space, geometry consisting of faces is created in the VR space. The created strokes can be set with various brush types, and when performing, a stroke with a red fire effect that matches a dynamic movement was used. It was made to be able to harmonize with the dancers performing the Bongsan mask dance. The medium called VR has characteristics that are not suitable for melting into a performance, but in this performance, it has overcome its limitations by using a technique called media façade. We propose the world's first performance technique that combines interactive strokes with traditional dance performances.

A Study on the Development of Application Schema for GML based ENC (전자해도용 GML을 위한 응용 스키마 개발연구)

  • Oh, Se-Woong;Park, Jong-Min;Cho, Deuk-Jae;Suh, Kee-Yeol;Park, Sang-Hyun;Suh, Sang-Hyun
    • Journal of Navigation and Port Research
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    • v.30 no.8 s.114
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    • pp.623-629
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    • 2006
  • Recently, bemuse of extensive use of hydrographic information, interoperability of Marine Geographic products is very important for efficient use of geographic information systems. Open GIS Consortium(OGC) developed the Open Geodata Interoperability Specification(OpenGIS) to support the interoperability in the distributed environment, especially Geography Markup Language(GML) Implementation Specification. Geography Markup Language is an XML grammar written in XML Schema for the modelling, transporting, and storing of geographic information GML provides a variety of objects for describing geography including features, coordinate reference systems, geometry, topology, time, units of measure and generalized values. S-57 is currently the IHO standard for the exchange of digital hydrographic data. To date, it ms been used almost exclusively for encoding Electronic Navigational Charts(ENCs). Even though, S-57 is intended to support all types of hydrographic data. In order to meet this requirement, a new standard is being developed. GML will be the core encoding rule of IHO's new standard. But there has been no study that tried to develop the GML for ENC that are recognized as base mop in the Marine GIS. This paper presents the process and results on development of application schema for converting ENC into GML.

Influence of electrode geometry on electrical resistivity survey: Numerical study (전극의 기하학적 형상이 전기비저항 탐사에 미치는 영향: 수치 해석 연구)

  • Tae-Young Kim;Seung-Hun Lee;Hee-Hwan Ryu;Song-Hun Chong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.2
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    • pp.101-120
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    • 2023
  • Electrical resistivity survey have been widely conducted at diverse scales, from a few centimeters for laboratory tests to kilometers for field tests. It measures electrical resistance through relationship of electric potential difference and current between two electrodes penetrated on the surface of medium, and eventually quantifies electrical resistivity known as inherent properties of the medium. In field or full-scale test, it assumes the electrodes as equivalent half-sphere electrodes that have a same surface area with different electrodes for ease of calculation because the contact area between electrode and medium is small and sufficient distance between two electrodes. However, small-scale laboratory test is significantly affected by the electrode geometries (penetrated depth, height, radius of electrode and distance between electrodes), which change the equipotential surface and electric current flow. Indeed, the electrode geometries may eventually cause a difference of electrical resistivity value. This study reviews the theoretical electrical resistance derived with various electrode geometries (half-sphere, cylinder, cylindrical with half-spherical tip, cylindrical with conical tip) and verifies the developed numerical module by comparing results with the theoretical electrical resistance. The distributions of electrical resistance around electrodes and among electrodes are analyzed. In addition, it is discussed how the electrical characteristic of cylindrical electrode with conical tip widely used in field test has effect on the electric current flow.