• Title/Summary/Keyword: different shapes

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Image Registration Based On Statistical Descriptors In Frequency Domain

  • Chang, Min-hyuk;Ahmad, Muhammad-Bilal;Lee, Cheul-hee;Chun, Jong-hoon;Park, Seung-jin;Park, Jong-an
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1531-1534
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    • 2002
  • Shape description and its corresponding matching algorithm is one of the main concerns in MPEG-7. In this paper, a new method is proposed for shape registration of 2D objects for MPEG-7 Shapes are recognized using the Hu statistical moments in frequency domain. The Hu moments are moment-based descriptors of planar shapes, which are invariant under general translation, rotational, scaling, and reflection transformation. The image is transformed into frequency domain using Fourier Transform. Annular and radial wedge distributions fur the power spectra are extracted. Different statistical features (Hu moments) are found f3r the power spectrum of each selected transformed individual feature. The Euclidean distance of the extracted moment descriptors of the features are found with respect to the shapes in the database. The minimum Euclidean distance is the candidate for the matched shape. The simulation results are performed on the test shapes of MPEG-7.

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Analysis of Korean Adult Male Leg Shape -Focus on Body Mass Index- (한국 성인 남성의 다리 유형화 -체질량 지수를 중심으로-)

  • Sujoung Cha
    • Journal of Fashion Business
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    • v.28 no.4
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    • pp.74-92
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    • 2024
  • This study aimed to classify leg shapes of adult males according to their obesity levels and examine characteristics of each type. The goal was to provide essential data for developing tight-fit pants patterns for adult males. Factors defining leg shapes of adult males were identified as leg horizontal factor, leg vertical factor, ankle thickness factor, and ankle height factor. Leg shapes were categorized into four types: 1) type 1, medium-thick, short legs with thin, medium-height ankles; 2) type 2, medium-thick, long legs with thin, low-height ankles; 3) type 3, thin, medium-length legs with thick, high-height ankles; and 4) type 4, thick, short legs with thick, medium-height ankles. The higher the obesity level, the greater the proportion of type 4, whereas the lower the obesity level, the greater the proportion of types 2 and 3. This suggests that as obesity levels increase, the number of individuals with very thick legs, thick ankles, and shorter legs also increases. Implications of leg shape according to obesity levels in adult males are as follows. First, different age groups require distinct pants patterns. Second, when grading sizes, the variation by body part should be adjusted according to age group. This study is significant as it classifies leg shapes of adult males based on obesity levels and examines characteristics of each type.

A Study on the SRM Torque Computation According to Different Stator Pole Shapes (스위치드 릴럭턴스 전동기의 스테이터 형상에 따른 토크량 계산에 관한 연구)

  • Jo, Hee;Lee, Jong-Woo;Kim, Kyeong-Hwa
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.693-696
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    • 2011
  • The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

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An Experimental Study on the Heat Transfer Characteristics of Corrugated Impinging Jets (파형 충돌분류의 열전달 특성에 관한 실험적 연구)

  • Kim, Ye Yong;Kim, Kui Soon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.3
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    • pp.320-329
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    • 1999
  • An experimental study has been performed to investigate the heat transfer characteristics of impinging jets with corrugated nozzle and wake generation plate. Three different shapes of corrugated nozzle and five different shapes of wake generation plate were tested to improve the heat transfer characteristics of impinging jet. Heat transfer coefficients were obtained by using transient method based on the liquid crystal thermography. The effects of corrugated nozzle and wake generation plate on the heat transfer characteristics of impinging jets were discussed in detail. The results showed that both the corrugated nozzle and the wake generation plate improved the heat transfer characteristics of impinging jet. Especially, heat transfer coefficients around stagnation region of impinging jets were highly increased.

Calculation of the flow field in the cylinder of the diesel engine for different bowl shapes and swirl ratios (보올형상과 선회비에 따른 디젤기관 실린더내의 유동장 해석)

  • 최영진;양희천;유홍선;최영기
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.2
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    • pp.50-66
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    • 1991
  • There are many factors which influence on the performance of a diesel engine. The piston bowl shape and swirl ratio are important factors to enhance the fuel-air mixing and flame propagation. In this study, calculations of the flow field in the cylinder of the diesel engine were carried out using the CONCHAS-SPRAY code for different bowl shapes and swirl ratios. In the case of constant swirl ratio, vortices which affect fuel-air mixing, evaporation and flame propagation are generated more strongly and consistently in the bowl-piston type combustion chamber than in the flat piston type. With this strong squish effect, injected fuel droplets are widely diffused and rapidly evaporated in the bowl-piston type combustion chamber. Especially a strong squish is developed and large and strong vortices are generated in the edge cutted bowl piston chamber. As the swirl ratio increases, it is found that a large and strong squish and vortices are generated in the combustion chamber and also fuel droplets are diffused into the entire combustion chamber.

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Mode Shape of Timoshenko Beam Having Different Circular Cross-Sections (다단 티모센코 원형단면봉의 연속 고유모우드)

  • 전오성
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.4
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    • pp.118-123
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    • 1997
  • The study suggests a method to analyze the vibration of the multi-stepped beam having the different circular cross-sections. The rotatory inertia, the shear deformation and the torque applied at both ends of the beam are considered in the governing equation. The complex displacement and the variable separation are introduced to derive the solution of the equation of each uniform beam element having constant cross-section. Then boundary conditions are applied to solve the total system. This method uses the mathematically exact solutions unlike numerical method such as the finite element method in solving the problem having the simultaneous differential equations of Timoshenko beam theory. the natural frequencies and the corresponding mode shapes are precise, especially the mode shapes are continuous.

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Propagation of floor impact vibration in a 1:10 scale model of a test structure (1:10 축척 시험동 구조 모형의 바닥충격 진동 전달)

  • Lee, Pyoung-Jik;Yoo, Seung-Yup;Kim, Jae-Ho;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1455-1458
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    • 2007
  • Vibration characteristics of concrete slabs were investigated using a 1:10 scale model and finite element method. A 1:10 scale model of a test building with 150 and 200mm slab thicknesses was made of acrylic materials. Modal test was conducted to investigate mode shape and modal frequencies. Results show that the mode shapes of two slabs with different thickness are similar each other, whereas natural frequency is different. Through modal analysis using FEM, it was revealed that both mode shapes and natural frequencies calculated from the FEM model are similar to those of the scale model measurement. It was also found that natural frequencies increased with increment of the slab thickness.

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Thermal performance comparisons of the glass evacuated tube solar collectors of different absorber tubes (진공관형 태양열 집열기의 내부형상 변화에 따른 성능 비교)

  • Kim, Yong;Seo, Tae-Beom;Yun, Seong-Eun;Kim, Young-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.595-598
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    • 2005
  • The thermal performance of glass evacuated tube solar collectors are numerically and experimentally investigated. Four different shapes of solar collectors are considered and the performances of these solar collectors are compared. Dealing with a single collector tube, the effects of not only the shapes of the absorber tube but also the incidence angle of solar irradiation (beam radiation) on thermal performance of the collector are studied. However the solar irradiation consists of the beam radiation as well as the diffuse radiation. Also, the interference of solar irradiation and heat transfer interaction between the tubes exist in an actual solar collector. These effects are considered in this study experimentally and numerically the accuracy of the numerical model is verified by the experimental results. The result shows that the thermal performance of the absorber used a plate fin and U-tube is the best.

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Effect of Wire Bracing to Snow Load Acting on Vinyl House Frame (적설하중이 작용하는 비닐하우스 골조에 대한 강선보강효과)

  • Jung, Dong-Jo;Teng, Chhay
    • Journal of the Korean Institute of Rural Architecture
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    • v.12 no.3
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    • pp.27-34
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    • 2010
  • Unbraced vinyl house frame that is economically installed is certainly easy to collapse under the influence of excess snow load. To make it more cheaply in putting up as well as more efficiently in withstanding the applied snow load, it is essential to insert additional bracing into the existing unbraced vinyl house frame. On the other hand, there are varieties of possible bracing shapes that can be formed. However, their efficiencies are different. Therefore, it is important to identify the most effective bracing shape. In this study, 2 different kinds of bracing shapes, horizontal and inclined bracing, are used to additionally install in the ordinary single frames in order to show the effect of the bracing resisting the applied snow load and compare the bending moment, axial force, combined stress and vertical displacement of the vinyl house frame.

Study of Signal Characteristics of Matrix Cracks in Composites Using Wavelet Transform (웨이블릿 변환을 이용한 복합재 모재균열의 신호특성 분석)

  • 방형준;김대현;강동훈;홍창선;김천곤
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.151-154
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    • 2002
  • The objective of this study is to find the change of signal characteristics of matrix cracks due to the different specimen shapes. As the concept of the smart structure, monitoring of acoustic emission (AE) can be applied to inspect the fracture of the structures in operating condition using built-in sensors. To understand the characteristics of matrix crack signals, we performed tensile tests by changing the thickness and width of the specimens. This paper describes the implementation of time-frequency analysis such as wavelet transform (WT) fur the quantitative evaluation of fracture signals. The experimental result shows the distinctive signal features in frequency domain due to the different specimen shapes.

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