• Title/Summary/Keyword: Slant

Search Result 381, Processing Time 0.027 seconds

Large Eddy Simulations on the Configuration Design of Afterbodies for Drag Reduction (저항감소를 위한 물체후방의 형상설계에 관한 LES 해석)

  • PARK JONC-CHUN;KANG DAE-HWAN;CHUN HO-HWAN
    • Journal of Ocean Engineering and Technology
    • /
    • v.17 no.5 s.54
    • /
    • pp.1-10
    • /
    • 2003
  • When a body with slant angle behind its shoulder is moving at a high speed, the turbulent motion around the afterbody is generally associated with the flow separation, and determines the normal component of the drag. By changing the slant angle of the afterbody, the drag coefficients can be changed, drastically. Understanding and controlling the turbulent separated flows has significant importance for the design of optimal configuration of the moving bodies. In this paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies, using slant angle. By understanding the structure of the turbulent flow around the body, the new configuration of afterbodies is designed to reduce the drag of body, and the nonlinear effects, due to the interaction between the body configuration and the turbulent separated flows, are investigated by use of the developed LES technique.

Stroke Extraction in Phoneme for Off-Line Handwritten Hangul Recognition (오프라인 필기체 한글 인식을 위한 자소 내 자획의 분리)

  • Jung Min-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.7 no.3
    • /
    • pp.385-392
    • /
    • 2006
  • This paper proposes a new stroke extraction algorithm for phoneme segmentation, which is one of main techniques for off-line handwritten Hangul recognition. The proposed algorithm extracts vertical, slant, and horizontal strokes from phonemes using run-length. The run-length of vertical or slant strokes becomes the width, and also the number of horizontal run-lengths the width. After extracting horizontal strokes from phonemes, the algorithm links two continuous vertical or slant stokes with run-lengths of the strokes' width to represent the features of a character. The extracted strokes can be utilized to recognize a character, using template matching of strokes, which is being adopted in on-line handwritten Hangul recognition.

  • PDF

Combined Mode I / III Stress Intensity Factor Analysis of a Crack in a Variable Thickness Plate (두께가 변화하는 부재 내의 혼합모드 I / III 균열의 응력확대 계수해석 - 3차원 유한요소해석 중심으로 -)

  • 양원호;최용식;조명래
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.15 no.2
    • /
    • pp.112-120
    • /
    • 1993
  • Variable thickness plates are commonly encountered in the majority of mechanical/structural components of industrial applications. And, as a result of the unsymmetry of the structure or the load and the anisoptropy of the materials, the cracks in engineering structures are generally subjected to combined stresses. In spite of considerable practical interest, however, a few fracture mechanics study on combined mode crack in a variable thickness plate have carried out. In this respect, combined mode 1/3 stress intensity factors $K_{1}$ and $K_{3}$ at the crack tip for a variable thickness plate were obtained by 3-dimensional finite element analysis. Variable thickness plates containing a central slant crack were chosen. the parameters used in this study were dimensionless crack length .lambda. crack slant angle .alpha, thickness ratio .betha. and width ratio .omega. Stress intensity factors were calculated by crack opening displacement(COD) and crack tearing displacement(CTD) method proposed by Ingraffea and Manu. The effect of thickness ratio .betha. on $K_{1}$ is relatively great in comparison to $K_{3}$.

  • PDF

A Comparative Study on Raglan-Sleeve Patterns According to Construction Factors (구성요인에 따른 래글런 슬리브 패턴의 비교 연구)

  • 이경화;조재희
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.26 no.11
    • /
    • pp.1502-1513
    • /
    • 2002
  • The purpose of this study was to find relations between construction factors and adaptability on the 5 available raglan sleeve patterns through the drafting method. Also it was to suggest a functional sleeve pattern according to appearance and adaptability test. Three women in her twenties who have standard figure was selected as subjects. Raglan sleeves of 5 experimental clothes were rated by the appearance test and adaptability test. The major conclusions of this study are as follows. 1. The construction factors of the raglan sleeve are sleeve slant, sleeve cap height, biceps line, breast width. Bicep lines increased and sleeve cap height decreased as the sleeve slant decreased. The higher adaptability scores of raglan sleeves were, the lower sleeve slants were. 2. According to the appearance evaluation, B type was recorded the highest score 3. According to the adaptability scores, A type was recorded the highest score. In the pulled length of the waist-line, A type was the lowest movements among the pattern type. In the pulled length of the sleeve-line, A type was the lowest movements among the pattern types. Therefore A type was evaluated by the bort functional sleeve pattern type. Through the experiments, it was known that appearance and adaptability of the raglan sleeve patterns were effected by construction factor.

Large Eddy Simulations on the Configuration Design of Afterbodies for Drag Reduction (저항감소를 위한 물체후방의 형상설계에 관한 LES 해석)

  • Park, Jong-Chun;Kang, Dae-Hwan;Chun, Ho-Hwan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2003.05a
    • /
    • pp.49-55
    • /
    • 2003
  • When a body with slant angle after its shoulder is moving at high speed, the turbulent motion around the afterbody is generally associated with the flaw separation and determines the normal component of the drag. By changing the slant angle of afterbody, there exists a critical angle at which the drag coefficients change drastically. Understanding and control of the turbulent separated flows are of significant importance for the design of optimal configuration of the moving bodies. In the present paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies with slant angle. By basis of understanding the structure of turbulent flaw around the body, the new configuration of afterbodies are designed to reduce the drag of body and the nonlinear effects due to the interaction between the body configuration and the turbulent separated flows are investigated by use of the developed LES technique.

  • PDF

Effects of Minimum Furrow Mulching with Weed Straw and Gravel Furrow Barrier on Soil Conservation at Potato Field in Gangwon Highland (골부초와 자갈대에 의한 고랭지 감자재배지 토양보전 효과)

  • Park, Chol-Soo;Jung, Yeong-Sang;Joo, Jin-Ho;Lee, Won-Jung;Yang, Jae-E.
    • Korean Journal of Environmental Agriculture
    • /
    • v.24 no.1
    • /
    • pp.29-33
    • /
    • 2005
  • To develop proper soil management practices for reducing soil erosion, experiments were carried out by using lysimeters in Pyeongchang highland, Korea. Lysimeters installed at Hoenggye bad 13% slope, 15 m slope length and 3 m width. Lysimeters with 23% slope, 15 m slope length and 3 m width were also installed at Yongsan. Soil textures in Hoenggye and Yongsan lysimeter plots were silty clay loam and sandy loam, respectively. In the lysimeters potato was cultivated, and slant furrow culture and contour culture were applied. Up-down furrow and continuous fallow lysimeter was included in the experiments as a control plot. For the slant furrow and contour culture methods, minimum furrow mulching and gravel barrier were placed at each end of the furrows in the lysimeters from April to October in 2000 and 2001 to prevent soil and nutrient losses. In Heonggye, in two years experiments, average soil loss of 17 Mg/ha was found in the up-down and continuous fallow lysimeter and 2.6 Mg/ha from furrow minimum straw and slant furrow treatment, and 1.8 Mg/ha from slant furrow and gravel bag treatment. In the contour culture, the soil losses were further reduced. In Yongsan, soil loss in the slant furrow culture without any protection treatment was 167 Mg/ha, and the soil loss was reduce to 61 and 86 Mg/ha with minimum straw and gravel bag treatments, respectively. The soil loss could be reduced more than 45% by furrow minimum straw and gravel barrier. The furrow minimum straw or gravel bag barrier successfully reduced soil loss in clay loam soil in Heonggye, but still the treatments were not enough to reduce soil loss in saprolite piled sandy loam soil in Yongsan.

Photometric Stereo Calibration using Constraint on Light Source Directions (광원 방향에 대한 제한조건을 이용한 Photometric Stereo Calibration)

  • Jeong, Seong-Cheol;Nguyen, Viet Hung;Won, Sang-Chul
    • IEMEK Journal of Embedded Systems and Applications
    • /
    • v.8 no.2
    • /
    • pp.111-119
    • /
    • 2013
  • This paper proposes one method on photometric stereo calibration using the constraint on light source directions in which the light sources have the unknown tilt and slant angles but the slant angles are the same. First, the constraint is analyzed based on the equation of linear ambiguity which leads to the conclusion that another constraint should be added to solve the calibration completely. Later, the combination of constraint on light source directions and the constraint that there exists at least six surface patches having known albedos is exploited to resolve the linear ambiguity up to an accurate and close-form solution. The effective performance of the proposed method is demonstrated through experiment results.

A Study on Strength Evaluation of a Road Wheel of Multipurpose Tracked Vehicles (다목적전술차량의로드휠강도평가에관한연구)

  • Kam M.K.;Kim H.S.;Kim Y.J.;Kim W.I.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2005.06a
    • /
    • pp.473-476
    • /
    • 2005
  • Mobility of tracked vehicles is dependent on performance of its power equipment and suspension systems. Especially, its road wheels, components of its suspension systems, play an important role in distributing the vehicle weight on the ground and preventing from misguiding tracks. In this study, the maximum force acted on multipurpose tracked vehicles driven on the worst condition was calculated. And then FE analyses were carried out to evaluate the strength of the road wheels under the maximum force condition. For quality evaluation of the road wheels, FE simulations and experimental works were carried out under specific slant loads. Residual deformation for the slant loads was investigated and commented upon.

  • PDF