• Title/Summary/Keyword: Lower Support Structure

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Preminary Study on Stress Analysis of Rock-mass Support Structure using Laboratory Test and Numerical Simulation (실내실험과 수치해석을 이용한 암반지보구조물의 응력거동 분석을 위한 기초 연구)

  • Lee, Jae-Ho;Moon, Hong-Deuk;Yoo, Ji-Hyeung;Kim, Hyuk;Son, Yeong-Ju
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.825-831
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    • 2010
  • In this study is stress behavior of steel support structure is to identify basic research. Steel stress due to load step to determine the behavior of steel using strain gauge steel loading test was performed. Numerical analysis and steel loading test using strain gauge on the actual steel stress behavior was analyzed. First, when tensile loading 3.5tonf load side of the plastic behavior appeared. Elastic model, using numerical analysis and comparison of results, the actual value is saved and you can see some difference. This repeated loading tests on steel can be seen from the results of the stress behavior of the steel rather than the elastic behavior of elastic-plastic behavior is because you can see. In addition, the upper and lower steel stress in compression and tension behavior represents the behavior was similar, but different. Steel loading test results, Y-axis get a compression if X-axis is tension. The future based on this study, the stress sensitivity curve of magnetic anisotropy sensor for non-destructive stress measurement technique for the study will be performed. And the behavior of plastic zone and residual stress to determine the numerical analysis using non-elastic model is needed.

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A Study on the Strength Change of Used Pipe Support(II) (재사용 파이프서포트의 내력변화 연구(II))

  • Paik, Shin-Won;Ro, Min-Lae
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.120-125
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    • 2005
  • Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen at the time concrete is being placed. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies fire of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.

Plasma Uniformity Control Technology for Dry Etching (ICP Dry etcher) Equipment for Medium and Large Displays (중·대형 디스플레이용 건식 식각(ICP Dry etcher) 설비의 플라스마 균일도 제어 기술)

  • Hong, Sung Jae;Jeon, Honggoo;Yang, Ho Sik
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.3
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    • pp.125-129
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    • 2022
  • The current display technology tends to be highly integrated with high resolution, the element size is gradually downsized, and the structure becomes complicated. Inductively coupled plasma (ICP) dry etcher of various types of etching equipment is a structure that places a large multi-divisional antenna source on the top lid, passes current to the Antenna, and generates plasma using the induced magnetic field generated at this time. However, in the case of a device of a large area size, a support that can withstand a load structurally is necessary, and when these support portions are applied, arrangement of antenna becomes difficult, which causes reduction in uniformity. As described above, the development of antenna source of a large area having a uniform plasma density on the whole surface is difficult to restrict hardware (H/W). As a solution to this problem, we confirmed the change in uniformity of plasma by applying two kinds of specific shape faraday shield(FICP) to the lower part of the large area upper lid antenna of 6 and 8th more than that generation size. In this thesis, we verify the faraday shield effect which can improve plasma uniformity control of ICP dry etcher equipment applied to medium and large displays.

An Analysis of the Family/Kinship Rites in Urban Area (도시지역의 가조/친족의례 실태 분석)

  • 박혜인;조은숙
    • Journal of Families and Better Life
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    • v.19 no.4
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    • pp.167-184
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    • 2001
  • The purpose of this study is to investigate actual conditions of family/kin ritual transition and to find out relationships to socio-economic variables. For this purpose, 716 subjects of urban family were interviewed with questionnaires. The results of this study may be summarized as follows: 1. It was discovered the pervasive themes of family/kin ritual transition: westernization, commercialization, socialization, and cultural anomie. 2. In contemporary family/kin rites, traditional structure coexists with external westernized aspects under the influnce of industrialization and commercialization. The rites were continued to provide a place where participants reproduce the ideology of patriarchal family group, especially the strong parent-child ties and narrow kin relationships. 3. Respondents who support traditional ritual style are old, lower class, and Buddhist. 4. Respondents who support westernization and socialization of family/kin rites are young, higher class, and Christian. But family/kin rites are not affected by sex relatively.

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A Study on the Development of Block Support Height Adjustment Device Using Static Nonlinear Analysis (정적 비선형 해석을 이용한 블록 지지대 높이 조정 장치 개발에 관한 연구)

  • Chunsik Shim;Gwangsan Cheon;Daseul Jeong;Kangho Kim;Mutiara Setyaning Dwityas;Deokyeon Lee;Byeongguk Jeong;Byeonghwa Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.61 no.5
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    • pp.389-399
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    • 2024
  • Currently, shipyards are using ship block supports to hold various pre-erection (PE) blocks during ship construction work. The height adjustment method of the ship block support is performed by workers hammering and driving the wedge part, which requires repetitive high-load work. Accordingly, there are concerns about musculoskeletal diseases and safety accidents. To prevent safety accidents and improve work efficiency, this study developed a block support height adjustment device using a hydraulic cylinder. It was designed considering the ease of movement of the block support height adjustment device and the ease of adjusting the height of the block support by workers within the shipyard. Numerical analysis was conducted to confirm the critical points of the structural members of the designed block support height adjustment device and to verify the safety of the stress-based structure. As a result of the analysis, it was confirmed that the stress occurring at the critical point of the structural member was lower than the design allowable stress, making it structurally safe. Afterwards, the block support height adjustment device was redesigned for lightweight, and after verification of structural safety through numerical analysis, a prototype was manufactured and performance evaluation was conducted.

Variation of Current by the Building of Artificial Upwelling Structure(II) (인공용승구조물 설치에 의한 유동변화(II))

  • Hwang, Suk-Bum;Kim, Dong-Sun;Bae, Sang-Wan;Kheawwongjan, Apitha
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.9-14
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    • 2007
  • To illusσ'ate the variation of current around artificial upwelling structure which is located in the South sea of Korea, current measurements using ADCP (Acoustic Doppler Current Profiler) during neap and spring tides were carried out on 27th July(summer), 14th October and 30th November(Autumn), 2006. Current after the set up of artificial upwelling structure were shown different in the upper and lower layer, the boundary between the upper and lower layer was at $27{\sim}30m$ depth in summer. And the boundary layer was formed structure of three layer in Autumn. Upwelling and downwelling flow were occurred around the seamount, and these vertical flows were connected from surface to bottom The distribution of vertical shear and relative vorticity support the vertical flow around the seamount. The strength of vertical shear was higher and the direction of relative vorticity was anticlockwise (+) around the upwelling area.

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KSTAR Superconducting Magnet Supporting Post Prototype Manufacturing and Structural Load Test (KSTAR 초전도자석 지지각 시작품재작 및 구조시험)

  • 허남일;이영신
    • Progress in Superconductivity and Cryogenics
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    • v.3 no.1
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    • pp.45-49
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    • 2001
  • A magnet supporting post installed between the lower TF coil tooled by 4.5 K supercritical helium and the cryostat base is one of the most important components of the superconducting magnet supporting structure for KSTAR Tokamak. This structure should be flexible to absorb thermal shrink of the magnet and also should be rigid to support the magnet weight and the Plasma disruptions load. The Post was designed with stainless steel 316LN and CFRP that have low thermal conductivity and high structural strength at low temperature. In order to verify the possibility of fabrication and the structural safety. a whole scale prototype of the KSTAR magnet supporting post was manufactured and tested. Static and compressive cyclic load tests under the maximum Plasma vertical disruption load and the magnet dead weight were performed. The teat results showed that the magnet supporting post of KSTAR Tokamak was possible to manufacture and structurally rigid.

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The Industrial Safety and Health Activities and Effectiveness of Government Support Program in Very Small Manufacturing Workplaces (초소규모 제조업 사업장의 안전보건활동과 정부지원사업 효과)

  • YI, Kwan Hyung
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.131-137
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    • 2015
  • Last five years, Occupational injury rate is declining but still a standstill as 2%, if the rate of deaths all people from 2% to 1% in 2013, but decreased as, occupational safety and health in terms industrial accidents yet has a very weak structure in very small Manufacturing workplace. The purpose of this study was to survey a 1:1 directly person interviews with a structured questionnaire intended for 150 a very small manufacturing workplace. In the results, working with non-regular(informal) workers is one in 10 persons 11.7% and female workers is about three people on 10 persons with 31.0%, and that 75% of non-regular workers who are mainly engaged in the production line appeared. And the work-related injury and accident experience was 4.0% and the occupational injury rate was 1.24%, especially occupational injury rate of older workers was 3.65%, a female workers 1.72%. Workplace risk assessment carried out in response that it was very low as 9.3% of the total. In the technology and funding programs that are supported by the government, was highest with 62.7% of the clean support program awareness, awareness of the rest of the programs is about 10-14% lower. And the satisfaction of supporting a clean support program were the highest 81.3%.

Preparation of Porous Carbon Support Using Carbon Nanofiber (나노탄소섬유를 이용한 다공성 탄소담체의 제조와 반응 특성)

  • 김명수;정상원;우원준;임연수
    • Journal of the Korean Ceramic Society
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    • v.36 no.5
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    • pp.504-512
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    • 1999
  • The high-quality carbon nanofibers were prepared by chemical vapor deposition of gas mixtures of CO-H2 and C3H8-H2 over Fe-Cu and Ni-Cu bimetallic catalysts. The yield and structure of carbon nanofiber produced were altered by the change of catalyst composition and reaction temperature. The high yields were obtained around 500$^{\circ}C$ with e-Cu catalyst and around 700-750$^{\circ}C$ with Ni-Cu catalyst and the relatively higher yields were obtained with the bimetallic catalyst containing 50-90% of Ni and Fe respectively in comparison with the pure metals. The carbon nanofibers produced over the Fe-Cu catalyst at around 500$^{\circ}C$ with the maximum yields had the highest surface ares of 160-200 m2/g around 650$^{\circ}C$ which was slightly lower than the temperature for maximum yields. In order to examine the characteristics of carbon nanofibers as catalyst support Ni and Co metals were supporte on the carbon nanofibers and CO hydrogenation reaction was performed with the catalysts. The particle size distribution of Ni and Co supported over the carbon nanofibers were 6-15 nm and the CO hydrogenation reaction rate with the carbon-nanofiber supported catalysts was much higher than that over the other supports.

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Pore Structure and Separation Properties of Thin Film Composite Forward Osmosis Membrane with Different Support Structures (지지층 구조가 다른 복합 정삼투막의 기공구조와 분리 특성)

  • Ahn, Soo-Hyun;Kim, In-Chul;Song, Doo-Hyun;Jegal, Jonggeon;Kwon, Young-Nam;Rhee, Hee-Woo
    • Membrane Journal
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    • v.23 no.3
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    • pp.251-256
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    • 2013
  • In this study, acetylated methyl cellulose (AMC) was successfully used as a support layer of thin film composite (TFC) forward osmosis (FO) membrane. A selective polyamide active layer, interfacially polymerized, was coated on top of various substrate layers. The structure and performance of the TFC FO membrane based on the AMC substrate were compared with those of TFC FO membranes with different polymeric support layers. The experimental results showed that the AMC FO membrane performance was better than other FO membranes due to its characteristic morphology and lower back diffusion rate of salts.