• Title/Summary/Keyword: Slant Method

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Determination of Stress Intensity Factor for the Crack in Anisotropic Solids Using the Finite Element Method (유한요소법에 의한 이방성재료내 균열의 응력확대계수 결정)

  • Lim, W.K.;Jin, Y.K.;Kang, S.J.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.234-239
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    • 2001
  • The stress intensity factors have been widely used in numerical studies of crack growth direction. However in many cases, omissive terms of the series expansion are quantitatively significant, so we consider the computation of such terms. For this purpose, we used the finite element method with isometric quadratic quarter-point elements. For examples, infinite square plate with a slant crack subjected to a uniaxial load is analyzed. The numerical analysis were performed for the wide range of crack tip element lengths and inclined angles. The numerical results obtained are compared with the theoretical solutions. Also they were accurate and efficient.

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A Study on Size Transformation for Dot Pattern by the 4-Direction Line Segmentation Algorithm (4방향 선분 분리법에 의한 도트 패턴의 크기 변화에 관한 연구)

  • 정회경;이수연
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.6
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    • pp.1013-1019
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    • 1987
  • This paper proposes the four directional line segmentation method to transform the size of dot patterns such as character dot patterns, line drawings and so on, while maintaining the quality of original pattern. At the first, this method extracts three kinds of line segmentm, namely horizontal, vertical line and slant line, and then transforms dot patterns using the each rules which are appricable to each kind of extracted line segments. Our experimental results show that transformation of dot patterns can be succeed in good quality without implementing some kinds of smoothing processes, covering the continuous transforming ratio of 0.5 to N times.

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Smartphone Based FND Recognition Method using sequential difference images and ART-II Clustering (차영상과 ART2 클러스터링을 이용한 스마트폰 기반의 FND 인식 기법)

  • Koo, Kyung-Mo;Cha, Eui-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1377-1382
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    • 2012
  • In this paper, we propose a novel recognition method that extract source data from encoded signal that are displayed on FND mounted on home appliances. First of all, it find a candidate FND region from sequential difference images taken by smartphone and extract segment image using clustering RGB value. After that, it normalize segment images to correct a slant error and recognize each segments using a relative distance. Experiments show the robustness of the recognition algorithm on smartphone.

Effect of Tunnel Entrance Shape of High Speed Train on Aerodynamic Characteristics and Entry Compression Wave (고속전철의 터널입구 형상이 공력특성 및 터널입구 압축파에 미치는 영향)

  • Jeong, Soo-Jin;Kim, Woo-Seung;Zhu, Ming
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.6
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    • pp.111-118
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    • 2004
  • The work presented in this paper concerns the aerodynamic characteristics and compression wave generated in a tunnel when a high speed train enters it. A large number of solutions have been proposed to reduce the amplitude of the pressure gradient in tunnels and some of the most efficient solutions consist of (a) addition ofa blind hood, (b) addition of inclined part at the entrance, and (c) holes in the ceiling of the tunnel. These are numerically studied by using the three-dimensional unsteady compressible Euler equation solver with ALE, CFD code, based on FEM method. Computational results showed that the smaller inclined angle leads to the lower pressure gradient of compression wave front. This study indicated that the most efficient slant angle is in the range from $30^{\circ}$ to $50^{\circ}$. The maximum pressure gradient is reduced by $26.81\%$ for the inclined angle of $30^{\circ}$ as compared to vertical entry. Results also showed that maximum pressure gradient can be reduced by $15.94\%$ in blind hood entry as compared to $30^{\circ}$ inclined tunnel entry. Furthermore, the present analysis showed that inclined slant angle has little effect on aerodynamic drag. Comparison of the pressure gradient between the inclined tunnel hood and the vertical entry with air vent holes indicated that the optimum inclined tunnel hood is much more effective way in reducing pressure gradient and increasing the pressure rise time.

Target Geolocation Method Using Target Detection in Infrared Images (적외선 영상의 탐지 정보를 이용한 표적 geolocation 기법)

  • Kim, Jae-Hyup;Jeong, Jun-Ho;Seo, Jeong-Jae;Lee, Jong-Min;Moon, Young-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.3
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    • pp.57-67
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    • 2015
  • In this paper, we proposed the geolocation method using target detection information in infrared images. Our method was applied to geolocation system of hostile targets in ground-to-ground field. The major distortion that has bad effect of geolocation was composed of optic, topography, GPS(Global Positioning System) and IMU(Inertial Measurement Unit) of reconnaissance unit. We proposed enhanced geolocation method to cope with optic and topography distortion using polynomial fitting and slant-range calculation model to overcome earth curvature problem, and the result showed that the performance of our method was good for system requirements.

VELOCITY ESTIMATION OF MOVING TARGETS BY AZIMUTH DIFFERENTIALS OF SAR IMAGES;PRELIMINARY RESULTS

  • Park, Jeong-Won;Jung, Hyung-Sup;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.625-628
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    • 2007
  • We present an efficient and robust technique to estimate the velocity of moving targets from a single SAR image. In SAR images, azimuth image shift is a well known phenomenon, which is observed in moving targets having slant-range velocity. Most methods estimated the velocity of moving targets from the distance difference between the road and moving targets or between ship and the ship wake. However, the methods could not be always applied to moving targets because it is difficult to find the road and the ship wake. We adopted a method estimating the velocity of moving targets from azimuth differentials of range-compressed image. This method is based on an assumption that Doppler center frequency shift of moving target causes a phase difference in azimuth differential values. The phase difference is linearly distorted by Doppler rate due to the geometry of SAR image. The linear distortion is eliminated from phase removal procedure, and the constant phase difference is estimated. Finally, range velocity estimates for moving targets are retrieved. This technique is tested using an ENVISAT ASAR image in which several unknown ships are presented. The theoretical accuracy of this technique is discussed by SAR simulation. The advantages and disadvantages of this method over the conventional method are also discussed.

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Design of a New Flexible In-pipe Inspection Robot (새로운 구조의 유연한 배관탐사 로봇 설계)

  • Choi, Hyeung-Sik;Kim, Dong-Ho;Kim, Dong-Hyun;Lee, Jong-Hoon;Whang, Kwang-Il
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.1
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    • pp.175-183
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    • 2008
  • In this paper, a new in-pipe inspection robot was developed for inspecting a large number of circular pipe insides of the sea plant, ships, and buildings. A new pressure generation system was devised to inspect circular pipes with different diameters and to move up and down slant or perpendicular slopes inside of the pipe. Also, a design method was analyzed to decide the capacity of driving motor for the robot if the mass and maximum velocity of the robot are identified. According to the design specification, a robot was developed and was tested to verify the performance of the pressure generation system. For tests, a control system was developed.

Development of an In-Pipe Inspection and Cleaning Robot (배관 검사 및 청소 로봇의 개발)

  • Choi, Hyeung-Sik;Na, Won-Hyun;Kang, Dong-Wan;Kang, Hyung-Suk;Jeon, Ji-Gwang;Kim, Hyun-Sik
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.5
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    • pp.662-671
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    • 2009
  • In this paper, a robot was developed for in-pipe cleaning and inspecting a large number of circular in-pipes of sea plants, ships, and buildings. A pressure generation mechanism was devised to inspect circular in-pipes with different diameters and to move up and down slant or perpendicular slopes in-pipes. For inspection of the dark inner side of the pipe, a light system using LED which dissipats small electricity was developed. Also, a design method was analyzed to decide the capacity of driving motor for the robot when the mass and maximum velocity of the robot are identified. The robot developed based on the design specification, was tested to verify the performance of the pressure generation mechanism. In addition, a control system was developed for the test.

Cosmetic Lateral Canthoplasty: Preserving the Lateral Canthal Angle

  • Kim, Yeon-Jun;Lee, Kyu Ho;Choi, Hong Lim;Jeong, Eui Cheol
    • Archives of Plastic Surgery
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    • v.43 no.4
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    • pp.316-320
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    • 2016
  • Cosmetic lateral canthoplasty, in which the size of the eye is increased by extending the palpebral fissure and decreasing the degree of the eye slant, has become a prevalent procedure for East Asians. However, it is not uncommon for there to be complications or unfavorable results after the surgery. With this in mind, the authors have designed a surgical method to reduce complications in cosmetic lateral canthoplasty by preserving the lateral canthal angle. We discuss here the anatomy required for surgery, the surgical methods, and methods for reducing complications during cosmetic lateral canthoplasty.

Estimate for Possibility Area of Liquefaction Using GSIS, When an Earthquake is Occurred (GSIS를 이용한 지진시의 액상화 가능지구 예측)

  • 양인태;김동문;김재철;유영걸
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.1
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    • pp.67-75
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    • 2001
  • A liquefaction is one of the phenomena bring about the damage of many human lives and properties in a short time, when an earthquakes is occurred. Because the foundation becomes such condition as suspension, the structures slant or collapse in a moment. This study is to provide and classify the geological map, soil map, drainage network map and underground water level data, and to evaluate the possibility area of liquefaction with the experienced method and the earthquake-proof regulations of Korea by applying Geo-spatial Information System(GSIS).

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