• Title/Summary/Keyword: Shed

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Evaluation of the Input Status of Exposure-related Information of Working Environment Monitoring Database and Special Health Examination Database for the Construction of a National Exposure Surveillance System (국가노출감시체계 구축을 위한 작업환경측정과 특수건강진단 자료의 노출 정보 입력 실태 평가)

  • Choi, Sangjun;Koh, Dong-Hee;Park, Ju-Hyun;Park, Donguk;Kim, Hwan-Cheol;Lim, Dae Sung;Sung, Yeji;Ko, Kyoung Yoon;Lim, Ji Seon;Seo, Hoekyeong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.3
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    • pp.231-241
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    • 2022
  • Objectives: The purpose of this study is to evaluate the input status of exposure-related information in the working environment monitoring database (WEMD) and special health examination database (SHED) for the construction of a national exposure surveillance system. Methods: The industrial and process code input status of WEMD and SHED for 21 carcinogens from 2014 to 2016 was compared. Data from workers who performed both work environment monitoring and special health examinations in 2019 and 2020 were extracted and the actual status of input of industrial and process codes was analyzed. We also investigated the cause of input errors through a focus group interview with 12 data input specialists. Results: As a result of analyzing WMED and SHED for 21 carcinogens, the five-digit industrial code matching rate was low at 53.5% and the process code matching rate was 19% or less. Among the data that simultaneously conducted work environment monitoring and special health examination in 2019 and 2020, the process code matching rate was very low at 18.1% and 5.2%, respectively. The main causes of exposure-related data input errors were the difference between the WEMD and SHED process code input systems from 2020, the number of standard process and job codes being too large, and the inefficiency of the standard code search system. Conclusions: In order to use WEMD and SHED as a national surveillance system, it is necessary to simplify the number of standard code input codes and improve the search system efficiency.

Effects of Weaving Machine Characteristics on the Physical Properties of PET Fabrics (I) (직기 특성이 PET직물 물성에 미치는 영향(I))

  • 김승진;손준혁;강지만;박명환
    • Textile Coloration and Finishing
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    • v.16 no.4
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    • pp.26-35
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    • 2004
  • This study surveys the tension differences between Korean domestic and foreign looms and analyses fabric mechanical properties due to warp and weft tension differences using KES-FB system. Paper is divided by two parts. In this 1st paper, fabric is designed as 5 harness satin weave using 75d/36f warp and 100d/192f weft polyester filaments, and is woven by $Omega^\circledR$ rapier loom by Textec Co.Ltd and Picanol$-GTX^\circledR$ rapier loom by Picanol Co.Ltd respectively. These grey fabrics are processed on the same dyeing and finishing processes. Weavability is also analysed by measuring warp tension variation according to the warp position, the relationship between shed amount and the warp tension on one fixed heald frame is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Change of Vortex Dynamics in the Cylinder Wake by the Lock-on to Oscillatory Incident Flow (진동 유동장에서 유동공진에 의한 실린더 후류의 와류 특성 변화)

  • Kim, Won-Tae;Sung, Jae-Yong;Yoo, Jung-Yul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.11
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    • pp.1645-1654
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    • 2003
  • When vortex shedding is locked-on to a single frequency oscillatory flow, the variations of vortex dynamics are investigated using a time-resolved PIV system. Wake regions of recirculation and vortex formation, dynamic behavior of the shed vortices and the Reynolds stress fields are measured in the wake-transition regime at the Reynolds number 360. In the lock-on state, reduction of the wake region occurs and flow energy distributed downstream moves upstream being concentrated near the cylinder base. To observe the dynamic behavior of the shed vortices, the trajectory of the vortex center extended to the inside of the wake bubble is considered, which describes well the formation and evolution processes. The Reynolds stresses and their contributions to overall force balance on the wake bubble manifest the increase of the drag force by the lock-on.

Full-scale investigation of wind-induced vibrations of a mast-arm traffic signal structure

  • Riedman, Michelle;Sinh, Hung Nguyen;Letchford, Christopher;O'Rourke, Michael
    • Wind and Structures
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    • v.20 no.3
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    • pp.405-422
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    • 2015
  • In previous model- and full-scale studies, high-amplitude vertical vibrations of mast-arm traffic signal structures have been shown to be due to vortex shedding, a phenomenon in which alternatingly shed, low-pressure vortices induce oscillating forces onto the mast-arm causing a cross-wind response. When the frequency of vortices being shed from the mast-arm corresponds to the natural frequency of the structure, a resonant condition is created causing long-lasting, high-amplitude vibrations which may lead to the fatigue failure of these structures. Turbulence in the approach flow is known to affect the cohesiveness of vortex shedding. Results from this full-scale investigation indicate that the surrounding terrain conditions, which affect the turbulence intensity of the wind, greatly influence the likelihood of occurrence of long-lasting, high-amplitude vibrations and also impact whether reduced service life due to fatigue is likely to be of concern.

Effect of the Projectile and the Air-jet Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment(I) -Tension Characteristics & Loom Mechanism- (프로젝타일과 에어제트 직기특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 메커니즘 -)

  • Kim, Seung-Jin;Jung, Gee-Jin
    • Fashion & Textile Research Journal
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    • v.7 no.1
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    • pp.101-105
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    • 2005
  • This study surveys the warp and weft tension differences between projectile and air-jet looms and analyses the mechanical properties of worsted fabrics for garment with relation of these loom characteristics using KES-FB system. The paper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yarn and 1/30 Nm worsted weft yarn by projectile(Sulzer) and air-jet looms(Picanol PAT and OMNI), respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Effects of Rapier Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment (I) - Tension Characteristics & Loom Mechanism - (래피어 직기 특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 매카니즘 -)

  • Kim, Seung-Jin;Kang, Ji-Man
    • Fashion & Textile Research Journal
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    • v.6 no.6
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    • pp.765-771
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    • 2004
  • This study surveys the warp and weft tension differences among 3 types of rapier looms and analyses the mechanical properties of worsted fabrics for garment with relation of these looms characteristics using KES-FB system. Raper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yam and 1/30 Nm worsted weft yam by rapier looms such as FAST-R, THEMA-11-E and PICANOL-GTX respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Protect Measures and Impact of Electric Pole for Abnormal Tension of Messenger Wire (전력선 벤드 장력 작용에 대한 전주의 영향)

  • Cho, Hyeon-Seob;Kim, Young-Cho;Kim, Sung-Woon
    • Proceedings of the KAIS Fall Conference
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    • 2006.05a
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    • pp.302-306
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    • 2006
  • In this study, we analyzed the influence of electrical pole by FEM(Finite Element Method) and developed protective system by designing and interpreting protective system for electrical pole when abnormal strength worked on messenger wire. Protective system did not shed messenger wire under wind pressure and discontent load but did assign a part to preventing rupture of electrical pole through automatically shed messenger wire over fixed strength. Structure of protective system analysis by FEM and prove property by measuring tensile strength for practical product.

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Prediction of Hydrodynamic Forces and Moments Acting on a Body of Revolution by the Method of Surface Vortex Distribution (보오텍스 분포법(分布法)에 의한 회전체(回轉體)의 유체동력학적(流體動力學的) 힘과 모우멘트의 추정(推定))

  • Seung-Il,Yang;Chang-Sup,Lee;Chang-Gu,Kang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.20 no.1
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    • pp.35-46
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    • 1983
  • The hydrodynamic lift and moment acting on the bodies of revolution with pointed-end were calculated by the surface discrete vortex method. It was found, by direct computation, that the lift normal to the on-coming flow can be generated by introducing the shed-vortex to the unless otherwise purely potential model. The value of the destabilizing moment, which is called Munk moment, is reduced by the shed-vortex model, resulting in better agreement with the existing experimental values.

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A Study on the Protect Measures and Impact of Electric Pole for Abnormal Tension of Messenger Wire (조가선 이상 장력 작용에 대한 전주의 영향 및 보호 대책 연구)

  • Oh, Hun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.3
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    • pp.78-83
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    • 2006
  • In this study, we analyzed the influence or electrical pole by FEM(Finite Element Method) and developed protective system by designing and interpreting protective system for electrical pole when abnormal strength worked on messenger wire. Protective system did not shed messenger wire under wind pressure and discontent load but did assign a part to preventing rupture of electrical pole through automatically shed messenger wire over fred strength. Structure of protective system analysis by FEM and prove property by measuring tensile strength for practical product.