• Title/Summary/Keyword: expansion and contraction

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Identification and Reduction Method for Refrigerator Contraction and Expansion Noise (냉장고 수축팽창 소음원의 규명과 저감 방법)

  • Kim, Wonjin;Park, Seong Kyu
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.4
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    • pp.723-729
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    • 2013
  • The contraction and expansion noise of a refrigerator are investigated, and some effective methods are proposed to reduce the level and occurrence frequency of noise. First, the noise of a refrigerator is measured to estimate the frequency spectrum and occurrence frequency of noise. Second, a sound visualization was conducted using an acoustic camera to determine the location of the noise source. From the results, it was observed that the internal part mainly producing noise was the third shelf in the freezer room. A method to estimate the acceleration on the location of the noise source is introduced to analyze the contraction and expansion noise precisely and accommodate experimental convenience. Noise reduction methods such as the replacement of the existing shelf with glass shelves, adoption of rail slides, and increase of roughness on the contact surface of the shelf are proposed and tested.

A Modified Expansion-Contraction Method for Mobile Object Tracking in Video Surveillance: Indoor Environment

  • Kang, Jin-Shig
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.4
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    • pp.298-306
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    • 2013
  • Recent years have witnessed a growing interest in the fields of video surveillance and mobile object tracking. This paper proposes a mobile object tracking algorithm. First, several parameters such as object window, object area, and expansion-contraction (E-C) parameter are defined. Then, a modified E-C algorithm for multiple-object tracking is presented. The proposed algorithm tracks moving objects by expansion and contraction of the object window. In addition, it includes methods for updating the background image and avoiding occlusion of the target image. The validity of the proposed algorithm is verified experimentally. For example, the first scenario traces the path of two people walking in opposite directions in a hallway, whereas the second one is conducted to track three people in a group of four walkers.

A study of the variations by motion of the Lower body Using 3D Body Surface Scan Data of a man in his early twenties (3차원 스캐너를 이용한 20대 남성의 하반신 신축량 분석)

  • Sohn, Boo-Hyun;Hong, Kyung-Hi
    • Korean Journal of Human Ecology
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    • v.18 no.3
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    • pp.729-740
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    • 2009
  • This study is to research on the rate of expansion or contraction according to movement of the lower body of the man their twenties using Rapid Form software. And aim of this study is to get information of ease allowance in developing slacks pattern using 3D body surface scan data through comparison with existing slacks patterns. Considering on the contraction and expansion according to movement, it need to set the more ease allowance in hip circumference than waist circumference, and the more ease allowance in back hip width than front hip width in slacks. In crotch length, the length of front crotch is revealed contraction but the length of back crotch is revealed expansion. It is desirable lowering front waist line and raising back waist line to possess ease allowance in back crotch area. The length of side seam is revealed a little expansion but the length of inseam is showed a great expansion. To develop slacks pattern of scientific approach using 3D body surface scan data, it need to analysis the rate of expansion and contraction of the lower body based on the movement, shear deformation, slip in fabrics and skin, or in fabrics and fabrics, and slip down from waist line.

An ergonomic Study on the function of Slacks -On the Expansion and Contraction of the Skin Surface of the Lower Body- (Slacks의 기능성에 관한 인간공학적 연구 -동하부 및 대퇴부의 신축을 중심으로-)

  • 함옥상
    • Journal of the Korean Home Economics Association
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    • v.19 no.2
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    • pp.151-163
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    • 1981
  • This study was to investigate the changes of shape of the surface square measurements, the rate, measurements of expansion and contraction and correlation. In this study was found the following: 1. According to the developmental illustration of the shell it was revealed that there was a great change in the thigh area of the body. When the leg was raised and the waist bent forward the front sections of the abdomen were contracted and the center back of the hip was expanded. 2. It was found that the contraction was present in the girth of the back section and front section was expanded in the rate of the body surface. In the length from the middle waist to hip the front area showed a great deal of contraction the back area of the hip & thigh revealed a great deal of expansion. 3. By the somatometry, the measurements of the expansion and contraction of the body surface, there was a great change in waist and hip. It revealed that the maximum expansions of waist and hip line in the chair were 1.8cm and 4.08cm respectively. Therefor, when slacks are made at least the amount of ease of 1.8cm of waist line and 4cm of hip line must be made and the allowance of the center back of hip area must be made. 4. It revealed that there was a correlation between waist and hip girth.

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Thermal Expansion and Contraction Characteristics of Continuous Casting Carbon Steels (연속주조용 탄소강에서 상변화에 따른 열팽창 및 수축 거동)

  • Kim, H.C.;Lee, J.H.;Kwon, O.D.;Yim, C.H.
    • Korean Journal of Materials Research
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    • v.13 no.3
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    • pp.137-143
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    • 2003
  • The air gap between the metal and mold, formed by shrinkage during solidification, causes surface and subsurface cracks in the continuous casting process. Molten crack on the surface might also occur due to improper heat transfer between them. In order to compensate the air gap in mold design, the thermal contraction is an essential factor. In this study, the thermal contraction and expansion behaviors were examined from the ($\alpha$ and pearlite)/${\gamma}$ to ${\gamma}$/$\delta$ transformations in continuous casting steels by the commercial dilatometer and the self- assembled dilatometer with laser distance measurement. It was found that the thermal contraction and expansion behaviors were very dependant on the phase transformation of the ${\gamma}$/$\delta$ as well as ($\alpha$ and pearlite)/${\gamma}$. The sudden volume change from $\delta$ to ${\gamma}$ which might cause cracks in the continuous casting process, was observed on cooling just below the melting temperature by the self-assembled dilatometer.

An Ergonomic Study on the Function of the Basic Pattern of Clothing -On the Expansion and Contraction of the Skin Surface of the Upper Body- (의복 원형의 기능성에 관한 인간공학적 연구)

  • 함옥상
    • Journal of the Korean Home Economics Association
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    • v.17 no.4
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    • pp.1-14
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    • 1979
  • The functional problems of the basic pattern of clothing are a matter of the first importance to clothing construction. Therefore, the ergonomic analysis of the expansion and contraction of the upper body surface, due to motion, has become required. thus in order to obtain the measurements and rate of expansion and contraction of the upper body surface following from its motions, the development figure of " Shell" and somatometry were employed. The results obtained through the investigation can be summarized as follows : 1) According to the developmental figures of "Shell" the latitudes centering around the shoulder line present contractive tendencies by arm movement. The longitudes around the center back waist length are expansive tendencies when bent forward. In the case of a 15$^{\circ}$ lean backward posture, the longitudes around the center front waist length are expansive tendencies. 2) By somatometry, the region from the scapula to the axilla point the upper back with presents the greatest expansion (more than 30%). The region from scapla to arm presents the maximum rate of contraction. In considering the longitude , under the axilla waist length and the bust point waist length generally shows the greatest rate of expansion. 3) The bust point waist length and under the axilla waist length are of great importance to the basic pattern of clothing. and have expansive tendencies(6.3cm). Among the latitudes, the upper back width has the greatest tendency for expansion (7.83 cm). 4) The region which presents the greatest rate of the expansion and contraction is in the proximity of the arm. These results testify that the amount of room of the back width must be given consideration in constructing the basic pattern of clothing.pattern of clothing.

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A Study on the Variation of the Body surface Area by the Arm movements to Somatotype -The Subject of the College Men- (체형별 상복동작에 따른 상체의 체표면 변화에 관한 연구 -남자대학생을 중심으로-)

  • 김진경
    • Journal of the Korean Home Economics Association
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    • v.26 no.2
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    • pp.1-13
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    • 1988
  • The purpose of this study was to classify somatotype of males, to show changes of the body skin surface by the somatotype. The size of sample was 156 males between age 20 and 24. Somatotype classified into Bending somatotype, Standard somatotype, Turning over somatotype. And according to the somatotype, changing of the upper part of the body by the arm movements analyzed through gypsum experiment. The result obtained from this study were as follows; 1. the variation of the upper part of the body form by changing the am movements, by the increasing of movements, shoulder-point ws moved to be inside or upside, the anterior armpit point & armpit point were moved to the upside. 2. As a result of investigating into the rate of the expansion and contraction of the basic lines and body surface area by the arm movements, the rate of expansion and contraction of the basic lines by the arm movements, the side sea length showed the maximum rate of extension in 135 degrees, the shoulder length showed the maximum rate of contraction in 135 degrees. The rate of expansion and contraction on the body surface area by the arm movements showed the phenomenon of contraction, of items F1, F6, B1, B9 showed the phenomenon of extension, of items F3, F4, F8, F9, B8, B9. 3. According to somatotypes, items which show the significant difference were, of items f3, f8, b3, b8, F2, F7, F8, B3, B7, in all movements.

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Wet to Shrink: an Approach to Realize Negative Expansion upon Wetting

  • Sun, L.;Huang, W.M.
    • Advanced Composite Materials
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    • v.18 no.2
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    • pp.95-103
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    • 2009
  • Composites can be designed to have special properties, and even such properties that are difficult to find in nature. We propose a simple approach to realize negative expansion upon wetting, i.e., contraction upon wetting, using swelling materials. The key parameters in one-dimensional case are investigated, and the possible configurations for two and three-dimensional cases are presented. The feasibility is demonstrated through a simple test.

A Study on the Movement-Fitness according to the Surface changing of Lower-Limb -On the Movements and Shapes of Lower-limb- (하복의 체표변화에 따른 동작적합성에 관한 연구 -하복동작 및 체형을 중심으로-)

  • 박영득;서영숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.2
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    • pp.257-269
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    • 1996
  • The puropose of this study was to investigate the movement-fitness according to the surface changing of lower limb The experimental items were divided into the lower limb movements (5) and body-shapes (7). This study was done by the expansion and contraction rate consideration of length, girth Also, the lower half of body shape-change on the movements and body-shapes by flat shell was done simultaneously. The summarized findings resulted from experiments and investigation are suggested as follows; First, when commpared the expansion and contraction rate of the length and girth items, the expansion rate of the back crotch length (14~20%), hip girth (10~ 21%) and knee girth (6.2~18.5%) in rabbit leap movement was the most notable among all variables considered in this experimentation. On the others hand, the front croth length (-22~-52%) contracted remarkably. And big-thigh type was the most notable on the body-shape comparision. Second, in comparision of the expansion and contraction rate of the area on the blocks, the expansion of the hip (50~200%) and knee (51~74%) block was the most remarkable. Especially, in the sit on knees movement of the hip-down type expanded 209.4%. Third, in comparision of the lower half of body shape-change, on the movements and body- shapes by the flat shell, under the influence of knee-joint and hip-joint the shape-changs of the hip and knee block was the most notable. But the shape-change of the waist, abdomen, calf, and ankle was feeble.

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A Study on Error Characteristic of Flow Disturbance and Velocity for Electromagnetic and Ultrasonic Flowmeters (유속과 유동교란인자에 의한 전자식 및 초음파식 유량계의 오차특성 연구)

  • Lee, Dong-Keun;Park, Jong-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.12 no.5
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    • pp.33-38
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    • 2009
  • In this study, the effect of flow disturbance such as contraction, expansion pipe and velocity deviation from low velocity of $0.1\;^m/s$ to $2.5\;^m/s$ on the error characteristics of the flowmeter was studied. Flow experiments using flowmeter calibration facility of K-water were undertaken for the cases of ultrasonic flowmeter based on transit-time method and electromagnetic flowmeter. Experimental results are presented that measurement error of expansion pipe are larger than contraction pipe. It is shown that the minimum straight length were required to remain of ${\pm}0.5%$ error for electromagnetic flowmeter and ${\pm}2.0%$ error for ultrasonic flowmeter.