• Title/Summary/Keyword: Location of opening

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An Experimental Study on the Structural Performance of Openings at End Steel Beams (강재 단순보 단부에 근접한 개구부의 구조성능에 관한 실험적 연구)

  • Han, Dong-Ho;Yoon, Sung-Kee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.138-145
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    • 2020
  • This study was conducted to identify the structural performance of the opening in a location close to the support point in the perforated beam system of steel beams. In addition, structural performance was determined through experiments on reinforced openings using vertical and horizontal steel plates. In the steel simple beam, it was found that the opening was in a position closer to the support point, half the height of the steel beam (D/2), which was more appropriate than the height of the steel beam (D). In addition, the reinforcement effect of horizontal steel plate was greater than that of vertical steel plate reinforcement. Structural performance was improved when there was no gap between openings and steel plates.

An Experimental Study on the Structural Performance of Steel Beam with Opening Close to End Subjected to Cyclic Loading (반복하중을 받는 단부에 근접한 개구부를 갖는 강재보의 구조성능에 관한 실험적 연구)

  • Han, Dong-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.2
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    • pp.66-73
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    • 2021
  • In the existing study of steel beams with openings, openings are located at a location where the distance to the support point is equal to or greater than the section height. Considering the facilities using the openings in the steel beam, the distance from the opening to the support point may be closer than the height of the beam section. Therefore, research on this is needed. This study is an experimental study to understand the structural performance of beams with openings close to the ends subjected to Cyclic Loading. In addition, in this study, we want to understand the structural performance through experiments on beams with openings reinforced with vertical or horizontal steel plates.

A Fire Simulation of Light Railway Transit (경량전철시스템의 화재 시뮬레이션)

  • Won Chan-Shik;Lee Ki-Choon;Hur Nahmkeon;Mok Jae-Kyun
    • 한국전산유체공학회:학술대회논문집
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    • 2001.05a
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    • pp.170-175
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    • 2001
  • Fire inside light railway transit(LRT) was simulated for various fire scenarios using CFD analysis in order to assess the safety of passengers. Considered in the present paper are the effects of locations of fire, a fire size, an operation of ventilation system and an opening time of door on evolution of temperature and smoke concentration inside the LRT. For fire simulation, fire cells releasing heat and smoke corresponding to fire size were positioned at the location of fire. From the results, it is seen that the ventilation system and the opening time of door were the most important factors on temperature and smoke concentration inside the LRT

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Flagship Store Trends in the Retail Market: Exploring the Characteristics (유통시장의 플래그십 스토어 트렌드: 현황을 통한 고찰)

  • Park, Kyung-Ae
    • Fashion & Textile Research Journal
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    • v.13 no.6
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    • pp.917-925
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    • 2011
  • Flagship store opening is one of the most frequently reported retail news in which it is widely used to promote a new store opening. The purpose of this study was to explore the flagship stores on media reports. Flagship store cases were collected from the news article database of the largest internet portal in Korea. A total of 210 cases were collected and content-analyzed. Though various business types of flagship stores were observed, most were in fashion. The most common characteristic of the flagship cases was the location of the prime sites in a metropolitan city. Global luxury and designer fashion brands met most characteristics, but many flagship stores were not more than a brand-owned store. The flagship store term is emphasized with dramatic expressions and various promotional events for media interests and in turn for marketing communication effect.

Simplified Modeling of Deflagration in Vessels

  • Kim, Joon-Hyun;Kim, Joo-Hyun
    • Journal of Mechanical Science and Technology
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    • v.18 no.8
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    • pp.1338-1348
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    • 2004
  • A simplified method that models the deflagration process occurring in closed or vented vessels is described. When combustion occurs within the spherical or cylindrical vessels, the flame moves spherically or segmentally to the vessel periphery. The volume and area of each element along the propagating flame front are calculated by using simple geometrical rules. For instabilities and turbulence resulting in enhanced burning rates, a simple analysis results in reasonable agreement with the experimental pressure transients when two burning rates (a laminar burning rate prior to the onset of instability and an enhanced burning rate) were used. Pressure reduction caused by a vent opening at predetermined pressure was modeled. Parameters examined in the modeling include ignition location, mixture concentration, vented area, and vent opening pressure. It was found that venting was effective in reducing the peak pressure experienced in vessels. The model can be expected to estimate reasonable peak pressures and flame front distances by modeling the enhanced burning rates, that is, turbulent enhancement factor.

A study on the flow characteristics of compressed-gas flow rate control valve (압축가스 유량 제어밸브의 유동특성 연구)

  • Kim J. B.;Park W. G.;Han M. C.;Jung C. H.;An J. Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.10a
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    • pp.25-28
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    • 2004
  • The purpose of this paper is to present essential numerical data of FCV(Flow rate Control Valve) which is used in a projectile ejection system for a underwater vehicle. A commercial CFD code is applied to analyze the 3 dimensional viscous compressible flow field within the FCV as four cases of opening rate, 25, 50, 75, and $100\%$. The flow coefficient of each cases are mainly calculated. And other characteristics such as the location of shock wave and total temperature distribution are also determined.

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Effect of Circumferential Location of Local Well Thinning Defect on the Collapse Moment of Elbow (엘보우 붕괴모멘트에 미치는 국부 감육결함의 원주방향 위치에 대한 영향)

  • Kim Jin-Weon;Lee Jang-Gon
    • Journal of the Korean Society of Safety
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    • v.20 no.1 s.69
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    • pp.55-61
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    • 2005
  • The purpose of this study is to investigate the effect of circumferential location of local wall thinning defect on the collapse behavior of an elbow. Thus, the present study conducts three-dimensional finite element analysis on the 90-degree elbow containing a local wall thinning at intrados, crown and extrados of bend region and evaluates the collapse moment of wall thinned elbow under various thinning shapes and loading conditions. Combined internal pressure and bending moment are considered as an applied load. The internal pressure of $0\~20MPa$ and both closing and opening mode bending are employed. The results of analysis show that the reduction in collapse moment of the elbow by local wall thinning is more significant for a defect locating at crown than for a defect locating at intrados or at extrados. Also, the effect of internal pressure on the collapse moment of wall thinned elbow depends on the circumferential location of thinning defect and applied bending mode.

A Study on the Decision Factors and Satisfaction of SMEs

  • Yongsang PARK;Jaetae KIM
    • The Journal of Economics, Marketing and Management
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    • v.11 no.3
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    • pp.81-92
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    • 2023
  • Purpose: The purpose of this study is to identify the determinants of store occupancy based on the rental characteristics of small and medium-sized enterprises (SMEs) renting buildings across the country, and to analyze the satisfaction level after opening. Research design, data and methodology: The study conducted an empirical survey through questionnaires targeting individual business owners, corporate representatives, and executives and employees nationwide, including Seoul, Gyeonggi, and other metropolitan areas and provincial cities. Results: In this study, the most important factor that SMEs consider when deciding whether to rent a commercial building or office is financial characteristics, followed by management characteristics, location characteristics, building characteristics, and facility characteristics. In addition, management characteristics were found to have the greatest impact on rental satisfaction of SMEs, followed by financial characteristics, building characteristics, and location characteristics in order. Conclusions: Since the lessor cannot immediately improve the location characteristics or building characteristics, in order to increase the rental satisfaction of small and medium-sized businesses in a relatively short period of time, it is necessary to improve managerial characteristics such as prompt civil complaint handling and clean management of the building. In addition, it is analyzed that if the factors that can reduce the burden on the tenants are found in advance and reflected in the financial characteristics, the satisfaction of the tenants can be increased.

Structure Safety Analysis of Composite Lattice Structure with Inspection Window (복합재 격자구조물의 점검창 형상에 따른 구조안전성 해석)

  • Kim, Dong-geon;Bae, Ju-chan;Son, Jo-wha;Lee, Sang-woo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.6
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    • pp.94-103
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    • 2018
  • The purpose of designing composite lattice structure which applied to launching vehicle and tactical missile body is to minimize the thickness and weight for applied load. It is usually made of carbon fiber; fabricating with filament winding process over silicon mold, and provided with a window opening for inspection purpose if necessary. In this paper compression test is conducted without window opening in lattice structure and preliminary FEA is carried out to confirm its accuracy. And then FEA is performed for the case of window opening to evaluate the soundness and the safety factor of the structure. We have calculated for two kinds of window shape; rectangular one and hexagonal one. And we have calculated safety factors of the lattice structure with window opening in every case based on failure strength of rib and knot with varying the thickness and location of the window for hexagonal shape. Through our investigation, we have found out the followings; (1) the hexagonal shaped window is shown higher safety factor than rectangular one, (2) a window in a certain location is shown higher safety factor than others, (3) although the soundness of window structure is improved as increasing its thickness, a window of a certain thickness is shown higher safety factor than others because of stress concentration.

Measurement of the Spatial Scattering Dose by Opening, Closing Door and Installing Shielding : A Study on the Reduction of Exposure Dose in Radiography (문 개폐 여부와 차폐체 설치 유무에 따른 공간산란선량 측정 : X선 촬영 시 피폭선량 감소방안에 대한 연구)

  • Yoon, Hong-Joo;Lee, Yong-Ki;Lee, In-Ja
    • Journal of radiological science and technology
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    • v.42 no.6
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    • pp.477-482
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    • 2019
  • Recently, due to the increased use of medical radiation, the radiation exposure of radiation workers should be considered as well as medical exposure of patients. And it is recommended to close the door during radiography. however, In this study, when the door was inevitably opened for radiography, the proposed method was to install the shield as a method of reducing the exposure dose. And its efficiency was analyzed. In simple chest radiography, the measurement point was changed according to the measurement location. Dose rate were measured 10 times for each condition using a dosimeter. And the average value was derived. Using this, the change of dose according to the opening and closing of the door and the installation of the shield was analyzed. Using this, we compared and analyzed the dose change according to the door opening and closing and the installation of the shield, and significance was verified through the SPSS ver. 24. Depending on whether the door was opened or closed, 11,215.35%, 159.0%, 101.9% increased in front of the door in the consol room, behind the wall and behind the lead glass. Depending on the installing of the shield, the 49.2%, 29.6%, 19.9%, 30.6% decrease in front of the door in the examination and consol room, behind the wall and lead glass. In addition, statistical analysis was showed that there were significant differences in both the results according to whether the door was opened or closed and shielding(p<.05). Close the door during radiography. However, when the door should be opened, it was confirmed that the dose rate were reduced by installing the shield. Therefore, to optimize radiation protection, it is recommended to install shields when opening the door.