• Title/Summary/Keyword: Shape Factor

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Retardation Behavior and Crack-Through-Thickness of a Surface-cracked Specimen under Cyclic Load (피로하중을 받는 표면균열재의 관통거동 및 지연거동)

  • 남기우
    • Journal of Ocean Engineering and Technology
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    • v.5 no.1
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    • pp.88-96
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    • 1991
  • Fatigue life and retardtion behavior after through-thickness were examined experimentally by using a CT specimen and surface-cracked specimen. The material used was 3% Ni-Cr-Mo steel. The fatigue crack shape before through-thickness is almost semicircular, and the measured aspect ratio is larger than the value obtained by calculation using the K value proposed by Newman-Raju. It is found that the crack growth behavior on the back side after through-ghickness is unique and can be divided into three stages a, b and c. A retardation parameter has been used successfully to predict the growth of cracks in specimen, and in this time, retardation factor is 4.3. By using the crack propagation rule considering on retardation state and the K value proposed by the authors, the remarkable crack growth behavior and the change in crack shape can be evaluated quantitatively.

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Development of new fracture parameter for rigid inclusion with crack shape in creep material (크립재료의 균열형상 강체함유물에 대한 새로운 파괴역학 매개변수 개발)

  • Lee, Kang-Yong;Kim, Jong-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.12
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    • pp.2165-2171
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    • 1997
  • The analysis model is the infinite power law creep material containing the rigid inclusion with crack shape. The present analysis is performed using the complex pseudo-stress function method. The strain rate intensity factor is developed as new fracture mechanics parameter which represents the stress and strain rate distribution near a crack tip in power law creep material. The strain rate intensity factor is developed in terms of Kolosoff stress functions.

The Study on the Visual Effects of Stripe Patterns in onepiece Dress (원피스 드레스의 줄무늬 시각효과에 관한 연구)

  • Lee Kyoung Hee;Yun Jung Hae;Park Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.14 no.4 s.36
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    • pp.314-323
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    • 1990
  • The purpose of this study is to investigate the visual effect of stripe patterns in one-piece dress. The results of the visual effects are as follows; 1. Comparision with experimental stripe patterns; experimental stripe patterns are likely to appear to be fat and wide in shape, and to be rhythmic, active, modern, unstable, not beautiful and dislike in sense. 2. The correlation between terms; there is a considerable correlation between 'the whole body looks fat 'and' the upper body looks fat'(r=0.84) when experimental stripe patterns are compared with vertical stripe pattern. When experimental stripe patterns compared with horizontal stripe patterns, there is a considerable correlation between 'rhythmic' and 'active' (r=0.90). 3. The results of factor analysis: commonly, factor 1 resulted in character of bodily shape and factor 2 resulted in sensuous charactor.

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A Multi-Polynomial Synthesis Method for DRRD Cam Profile Optimizations and Effects of Shape Factors on the Cam Lobe Area (DRRD 캠 형상 최적 설계를 위한 다항식 합성법과 캠 로우브 면적에 미치는 형상 계수들의 영향)

  • 김도중;박성태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.4
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    • pp.59-71
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    • 1994
  • A multi-polynomial method is proposed to synthesize DRRD cam profiles. A cam lift duration s divided into 10 sections, each of them is expressed by a polynomial equation. 12 design variables are extracted from the cam profile displacement, velocity, and acceleration curves. Because all the design variables have physical meanings which are familiar to most cam designers, it is easy to imagine a profile shape from the design variables. The design envelope of the method is wide enough to be used in DRRD automotive cam designs. Polydyne cams, widely used in automotive engines, are included into the envelope. Unlike Polydyne cams, the method provides capability of wide velocity factor variations, which gives much flexibility in flat-faced tappet design. Area factor of profiles designed by the method can be increased 5-10% compared to those of Polydyne cams without increasing acceleration factor. The method is especially useful for cam profile optimizations.

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An Experimental Study on Heat Transfer and Pressure Drop of Air Side in a Plate-Louvered Fin Heat Exchanger (평판관-루버핀 열교환기의 공기측 열전달 및 압력강하 특성에 관한 실험적 연구)

  • 강병하;김석현;장혁재;박병규
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.6
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    • pp.485-492
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    • 2002
  • Heat transfer and pressure drop on the air side of a plate-louvered fin heat exchanger with new shape of louver fin have been investigated experimentally. Water is employed inside the flat tube to transfer heat with air for convenience. This problem is of particular interest in the design of a plate-louvered heat exchanger. The effect of air flow rate, water flow rate and water temperature on pressure drop as well as heat transfer in air side are studied in detail. The present results showed a good agreement qualitatively with the previous results in general. Based on the experimental data, f-factor and j -factor correlations of the present louvered-fin are suggested. It is also found that heat transfer could be enhanced with new shape of louver fin, compared with the conventional louvered-fin, while the f-factor remains unchanged.

A Development of Estimation Method for Texture in Human Sensibility Ergonomics (텍스처의 감성공학적 평가 기법의 개발)

  • 임기용;이상도;이동춘;윤훈용
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.50
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    • pp.151-160
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    • 1999
  • The relationship between the product design and product image can be defined using human sensibility. If there is a way to grasp the product value or product design that people want most, it could be possible to make and sell user-oriented products. In human sensibility ergonomics, the categories of design factor can be broken into shape and color of the design. Although, the color is the major factor of the design, however, texture were is also an important factor for the shape. In this study, wall-papers that have various shapes of texture were used for the experiment. The purpose of this study was to conduct a sensibility estimation experiment for the product image, and to estimate the parameters of various textures for creating new textures that could be more suitable for human sensibility.

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A Study on the Visual Effects According to Changes in Width of Pleats and Skirt Length of Accordion Pleats Skirt (아코디언 플리츠 스커트의 주름너비와 스커트길이 변화에 따른 시각적 효과)

  • Lee, Jung-Soon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.1
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    • pp.77-88
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    • 2010
  • The purpose of this study is to evaluate the differences of visual effects by variations in the width of pleats and the length of the accordion pleats skirt. The stimuli are 21 samples: 7 variations of the width of pleats and 3 variations of the length of skirt. The data has been obtained from 43 fashion design majors. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: The visual effects by the number of pleats and the length of skirt are composed of 2 factors: verticality and thickness of lower body, shape of abdomen. In these factors, verticality and thickness of lower body factor is estimated by the most important factor. The accordion pleats skirt makes the lower body look longer when the width of the pleats is wider, and helps the calf and leg look thinner. Also, the waist looks more slender and thin. As the skirt gets longer, one looks taller, and legs look longer and thinner. The shape of abdomen is no difference according to the width of pleats. As the skirt gets longer, the waist looks more slender and thinner. The interaction of visual effect according to the changes in width of pleats and skirt length of accordion pleats skirt is not shown, and the skirt length has more effect than the width of pleats does in verticality and width of lower body factor. The width of pleats has more effect than the skirt length does in shape of abdomen factor.

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A study on the visual effects according to changes in number of pleats and skirt length of pleats skirt (플리츠 스커트의 플리츠 수와 스커트 길이 변화에 따른 시각적 효과)

  • Kim, Kyung-Hee;Lee, Jung-Soon
    • Journal of Fashion Business
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    • v.13 no.5
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    • pp.81-92
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    • 2009
  • The purpose of this study is to evaluate the differences of visual effects by variations in the number of pleats and the length of the pleats skirt. The stimuli are 18 samples: 6 variations of the number of pleats and 3 variations of the length of skirt. The data has been obtained from 54 fashion design majors. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: The visual effects by the number of pleats and the length of skirt are composed of 3 factors : vertical of lower body, curves of lower body and shape abdomen. In these factors, vertical factor is estimated by the most important factor. The visual effect is positive when the number of pleats is added and the length of skirt is getting shorter. The short length of skirt and more pleats make legs and calves looked long and slim. The interaction effects between the number of pleats and the length of skirt do not appear. In the vertical of low body factor, the length of skirt is more effective than the number of pleats, and in the curve of low body factor, the number of pleats has more effects than the length of the skirt. In the shape of abdomen, the number of pleats and length of skirt have similar influences.

A Numerical Study on Improving the Thermal Hydraulic Performance of Printed Circuit Heat Exchanger Using the Supercritical Carbon Dioxide (초임계 이산화탄소를 작동유체로 한 PCHE의 열수력 성능 향상을 위한 수치해석적 연구)

  • Park, Bo Guen;Kim, Dae Hyun;Chung, Jin Taek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.10
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    • pp.779-786
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    • 2015
  • The objective of this study is to propose a new channel shape that improves thermal-hydraulic performance. The existing Zigzag channel has high pressure loss due to flow separation and reverse flow. To improve this disadvantage, partial straight channel is inserted into bended points. Also, the effects of straight channel's length change on heat transfer and pressure loss are analyzed. Thermal-hydraulic performance of the new shape and existing Zigzag channel are quantitatively compared in terms of Goodness Factor. Mass flow rate was changed from $1.41{\times}10^{-4}$ to $2.48{\times}10^{-4}kg/s$. The average volume goodness factor of 1mm straight channel shape was increased by 25% compared to the Zigzag channel.

The Visual Effects by Variation of the Shoulder Length and Puff Volume in Puff Sleeve Blouse (퍼프슬리브 블라우스의 어깨길이와 퍼프량의 변화(變化)에 따른 시각적(視覺的) 효과(效果))

  • Koo, Mi-Ran;Lee, Jung-Soon
    • Journal of Fashion Business
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    • v.11 no.4
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    • pp.82-91
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    • 2007
  • The purpose of this study is to evaluate the differences of visual effects by variations in the shoulder length and puff volume of the puff sleeve blouse. The stimuli are 21 samples: 3 variations of the shoulder length and 7 variations of the puff volume. The data has been obtained from 40 fashion design majors. The data has analyzed by Frequency, Factor Analysis, ANOVA, Scheffe's test and MCA method. The result of the study are as follows. The visual effects by the shoulder length and puff volume are composed of 4 factors : the width of the upper body, the shape of the breast part, the shape of the neck part and the shape of the upper arm. In these factors, the width of the upper body is estimated by most important factor. In view of the visual effects by variation of the shoulder length, the shorter shoulder length goes, the more positive visual image comes in the shape of the breast part. In comparison of the differences of visual effects by the 7 variations of puff volume, the arm looks thin and long when the puff volume goes enough and the breast part has a better visual assesment in case the puff volume goes poor. In the interaction effects between the shoulder length and puff volume, the shoulder length have significant differences in the shape of the breast part, the shape of the neck part and the shape of the upper arm and puff volume has significant difference in the width of the upper body.