• Title/Summary/Keyword: Light-weight

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Properties of Thermal Expansion Strain of Light Weight Aggregate Concrete with Loading Conditions (하중조건에 따른 경량골재 콘크리트의 열팽창변형 특성)

  • Yoon, Min-Ho;Kim, Gyu-Yong;Lee, Tae-Gyu;Nam, Jeong-Soo;Shin, Kyoung-Su;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.255-256
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    • 2012
  • In this study, strain properties of high strength concrete using light weight aggregate which is widely used in recent years are evaluated. For these purpose, thermal strain, transient creep were measured in prestressed condition as 0, 20, 40% of specimen strength at target temperature with 60MPa specimens which was using normal and light weight aggregate. As a result, light weight aggregate is more advantageous for the control of strain than normal aggregate because of its low thermal expansion.

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A Experimental Study on the Freezing and Thawing of High-Strength Light Weight Aggregates Concrete (고강도 경량골재콘크리트의 동결융해에 대한 실험적 연구)

  • 박정권;최세규;한상묵;김생빈
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.155-161
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    • 1997
  • This Expriment is performed to describe the properties of the freezing-thawing and to find the method to enhance the freezing-thawing resistance of the high strength light weight aggregates concrete. For this purpose, we made 8 kinds of specimen of concrete mold. The light weight coarse aggregate concrete which contained AE was appeared in good condition and its durability index was more than 90% by the buffer action which owing to entained air. The light weight aggregates concrete which admixture of silca fume, was appeared that the durability index was 46.74% in spite of its high strength. I might conclude that the most important factor for freezing-thawing resistance of high strength light weight aggregate concrete is the entrained air.

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An Experimental Study on the Sound Insulation Performance for Light-weight Concrete Panel (경량콘크리트 패널의 차음성능에 관한 실험적 연구)

  • Chung, J.Y.;Lee, S.H.;Jeong, G.C.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.457-460
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    • 2004
  • This study examines the sound insulation of the light-weight wall using light-weight concrete and offers the basic datum for enhancing it. The sound insulation of the light-weight wall is determinated by the density, installation method, absorption materials, air layers etc. Among the factors, the solution of outlet that is the major cause of reducing sound insulation should be made. If absorption materials are installed in the cavity walls, it enhances to 15dB in 500Hz.

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Heat Generation and Machining Accuracy According to Material for Ultra-Precision Machining (차량 경량화를 위한 이종소재 접합 연구)

  • Lee, Gyung-Il;Kim, Jae-Yeol;Lee, Dong-Gi
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.130-135
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    • 2018
  • Currently the automobile market is developing eco-friendly vehicles in order to cope with fuel efficiency regulations. Many studies have been conducted to improve travel performance and fuel economy of the environment-friendly vehicles, and vehicle manufacturers study how to manufacture light-weight vehicles for improving fuel economy for both existing vehicles and environment-friendly vehicles. Exemplary light-weight vehicle technologies include optimal design of vehicle body structure which is a light-weight vehicle method by changing component shapes or layout to optimize the vehicle body structure and the new process technology for using new light-weight and very strong materials Various studies.

The Effect of Seasonal Clothing Weight on Resting Metabolic Rate (계절별 착의량이 안정시 에너지 대사량에 미치는 영향)

  • 황수정;최정화;성화경
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.3
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    • pp.483-494
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    • 1999
  • This study investigated the relation between seasonal variation of clothing weight and its resting metabolic rate to determine the relation between proper living temperature and cold/heat tolerance. Thirty six subjects(18 males and females twenties) were composed to obtain the clothing weight(Total clothing weight) and resting metabolic rate for a year and grouped four seasons : spring (Mar-May) Summer(Jun-Aug) Fall(Sep-Nov) and Winter(Dec-Feb). The data of males and females were respectively divided into three groups by cluster analysis with clothing weight. 1. The resting metabolic rate of male(41.1kcal/m2/hr) was higher than that of female(33.2kcal/m2/hr). It is suggested there is gender difference in the resting metabolic rate(p<.001) 2. The resting metabolic rate of male and female was the highest in Winter. It is suggested there is seasonal variation in the resting metabolic rate(p<.001) 3. It was found that there was relation between clothing weight and resting metabolic rate. The difference of resting metabolic rate between Summer and Winter which is profitable to adaptation to living temperature was significant in light clothing weight in male as well as in female. 4. In comfortable sensation most subjects responded that he/she felt 'comfortable' except Winter. However the heavy clothing weight group felt 'a little uncomfortable' throughout all seasons. l In thermal sensation most subjects responded that he/she felt 'neutral' And then the heavy clothing weight group responded warmer in summer and cooler in winter than light clothing weight group. From the results it was confirmed that male and female showed seasonal variations in clothing weight and resting metabolic rate. Also the resting metabolic rate of male and female was influenced by the clothing weight. In short seasonal variation of resting metabolic rate was larger in light clothing weight group than in heavy clothing weight group. Therefore light clothing weight group is advantgeous in living temperature to improve cold/heat tolerance and it also shows that living with the light clothing weight may enhance the degree of adaptation to change of living environment

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A Development of MiTS Service Modules based on Light-Weight Ethernet (Light-Weight Ethernet 기반 MiTS 서비스 모듈 개발)

  • Hwang, Hun-Gyu;Yoon, Jin-Sik;Seo, Jeong-Min;Lee, Seong-Dae;Lee, Jang-Se;Park, Hyu-Chan;Jang, Kil-Woong
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.8
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    • pp.1180-1187
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    • 2010
  • In these days, data processing rate is increasing on shipboard. To solve the problems on the rate, Ethernet based IEC 61162-4 series standard established for integrated information management. But the standard is difficult to implement, so it is changed into Light-weight Ethernet standard. In this paper, we analyze the existing standard and compare it with Light-weight Ethernet standard. As a result, we draw its service requirements. Also we propose the services, and design and implement the service modules.

A Study on Statistical Methods for the Light Weight Estimation of Ultra Large Container Ships (초대형 컨테이너선의 경하중량 추정을 위한 통계적 방법 연구)

  • Cho, Yong-Jin
    • Journal of Ocean Engineering and Technology
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    • v.23 no.3
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    • pp.14-19
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    • 2009
  • The present study developed a model to estimate the light weight of an ultra-large container ship. The weight estimation model utilized container ship data obtained from shipyards and the subdivided this weight data into appropriate weight groups. Parameters potentially affecting the group weight were selected and expanded based on experience for weight estimation, and a correlation analysis was performed by the SPSS program to determine the key parameters characterizing the group weight. A weight estimation model applying the multi-regression analysis was proposed to assess the weight of an ultra-large container ship at the preliminary design stage, and the results obtained by the suggested method showed good agreement with the shipyard data.

A Study on the Light Weight Hand Lamp for Explosion-Proof Type (휴대형 방폭등의 경량화 연구)

  • Choi, Sang-Won
    • Journal of the Korean Society of Safety
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    • v.28 no.2
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    • pp.31-36
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    • 2013
  • For lighting of dark and hazardous workplace such as compartment of ships under construction, workers should use hand lamps of explosion-proof type. However, the heavy weight of such lamps has prevented most impatient workers from using such types of lamps extensively. In this paper, we developed a light weight hand lamp of intrinsic safety type which reduced the weight a lot while maintaining or improving the lighting and explosion-proof function. We made a prototype which consisted of lamp fixture and high frequency power supply. Testing results show that the hand lamp meets well all the explosion-proof testing requirements of the Korea Occupational Safety and Health Agency. And more, we surveyed the explosion protection technology of a light weight hand lamp, and suggested the advantage/disadvantage to apply lighting of hand lamp about economical aspect.

Development of Eco-Friendly Light Weight Form for Increased Formwork Productivity (거푸집공사의 생산성 향상을 위한 친환경 경량 거푸집 개발)

  • Ahn, Hee-Jae;Lee, Dong-Min;Lee, Dong-Youn;Cho, Hun-Hee;Kang, Kyung-In
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.8-9
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    • 2019
  • Euro forms and aluminum forms, which are currently used in formwork construction sites are limited by their heavy weight and the use of environmentally hazardous form oils. Therefore, in this study, 'eco-friendly light weight form' was developed, which does not require form oils during the removal process of form. In addition, the superiority of the developed form was verified by comparison with Euro forms and aluminum forms in terms of noise generation and weight. Application of the eco-friendly light weight form in construction sites is expected to reduce the noise level, and increase workers' convenience. The productivity of formwork is also increased.

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A Research about light-weight design of selfie-rod with FreeCAD (FreeCAD를 이용한 스마트폰 셀카봉의 경량화 설계에 관한 연구)

  • Moon, KweonWoo;Hwang, Hyun-Tae
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.541-542
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    • 2015
  • Recently, a popularity of the smartphone is on the rise. And also related services are being created. The growth of the smart technology makes advanced equipment for smartphone accessories. Selfie-rod is one of them. Selfie-rod satisfies people who want to take their own picture at long distance. However, the weight of recent selfie-rods is too heavy that has nice functions. So, we have re-designed new selfie-rod that has light-weight body. First, we observed a selfie-rod and check the reason of the selfie-rod's high weight. The new selfie-rod has a shell and inside, there is a space that it can be light-weight. The shell and space make the selfie-rod lighter. In FreeCAD, we designed shell with a rotation function. Finally, we designed light-weight body selfie-rod with FreeCAD. FreeCAD can be used easily for beginners of CAD. FreeCAD is suitable 3D-design tool for era of 3D-printing.

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