• 제목/요약/키워드: Present conditions

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아파트 거주자의 물품수납 의식 및 만족도 연구 -침실을 중심으로- (A Study on Apartment Resident's Satisfaction and Recognition on Storage Space in Bedrooms)

  • 박영순
    • 대한가정학회지
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    • 제28권4호
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    • pp.51-63
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    • 1990
  • The purpose of this study is to find out the present conditions and the residents' satisfaction with the storage spaed and furniture in apartment smaller than 40 pyoun(132㎡). The following were investigated; 1. the rate of residents using beds and their future desire for using beds. 2. the rate of households that have built-in furniture, and residents' desire for having them. 3. types of storage furniture more needed. 4. residents' level of satisfactio with the present storage space. 5. the depths of wardrobes and the heights of racks inside wardrobes. 6. storing conditions of articles seasonal or seldom used.

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한전의 송변전분야 연구현황 및 추진계획 (Present Research Conditions and Plans of Transmission and Substation Department in KEPCO)

  • 정길조;권동진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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    • pp.609-612
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    • 2000
  • This paper describes present research conditions and plans of transmission and substation department in KEPCO. We describe an overview of general status of research environment in KEPRI. And we describe the results of the research in 1999, items of the research in 2000 and research plans of the long and short terms in transmission and substation department.

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프레스 작업의 재해 현황에 따른 안전대책에 관한 연구 (- A study for the safe preventions by the present conditions of the industrial accidents in the press working -)

  • 정재수;정수일
    • 대한안전경영과학회지
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    • 제5권2호
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    • pp.27-40
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    • 2003
  • In this study, it was researched a kind of the press machines which had been retained in the domestic press working companies. And then it was analyzed the present conditions with the working types, companies size, the aging types and the continuous working periods. Specially, the purpose of this paper is decreased the industrial accidents of the domestic press working companies by the proposing the safe prevention which are obtained by the analysing the accidential reasons.

프레스 작업의 재해 현황에 따른 안전대책에 관한 연구 (A study for the safe preventions by the present conditions of the industrial accidents in the press working.)

  • 정재수;정수일
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2003년도 춘계학술대회
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    • pp.27-36
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    • 2003
  • In this study, it was researched a kind of the press machines which had been retained in the domestic press working companies. And then it was analysed the present conditions with the working types, the size of companies, the aging types and the continuous working periods. Specially, the purpose of this paper is decreased the industrial accidents of the domestic press working companies by the proposing the safe prevention which are obtained by the analysing the accidential reasons.

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콘크리트 구조물의 단일 및 복합열화 환경하에서의 염소이온 확산특성 (Diffusion Characteristics of Chloride ion under Single and Combined Attacks in Concrete Structures)

  • 오병환;강의영;인광진;이성규;서정문
    • 콘크리트학회논문집
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    • 제14권5호
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    • pp.708-717
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    • 2002
  • 해안 등 열악한 환경에 노출되는 구조물들의 건설이 증가되면서 구조물의 내구성 문제가 심각해지고 있다. 특히, 염해만이 아니라 염해와 황산염 그리고 중성화 등 복합작용에 의한 열화문제는 아직도 연구된 바가 거의 없는 실정이다. 따라서, 본 연구에서는 염해와 황산염 및 중성화가 복합된 환경하에서 콘크리트 구조물의 성능저하 현상을 살피고 이들의 상호작용과 영향을 실험적으로 구명하는데 그 목적을 두고 있다. 이를 위해서 단일 및 복합열화 실험을 포괄적으로 수행하였다. 본 연구결과, 염소이온 단일열화시 보다 황산염 또는 황산염과 중성화가 복합되었을 경우의 열화현상이 더 두드러졌으며, 모든 열화조건에서 표면염소이온의 농도는 시간에 따라 증가하고 반면에 확산계수는 시간에 따라 감소하는 경향을 나타냈다. 표면염소이온 농도는 복합열화에서 더 증가하며 특히 염소이온 확산계수는 염해와 황산염 2중 복합열화시 더 커지고 여기에 중성화가 복합될 경우 더욱 커지는 것으로 나타났다. 따라서, 해안 구조물과 같이 염해와 황산염 및 중성화가 복합될 경우 염소이온의 침투가 더욱 커져 이들의 합리적인 고려가 필요한 것으로 나타났다.

수심 변화에 따른 볼라드 당김 및 과부하 조건에서의 다중 포드 추진 쇄빙선박의 여유추력 추정에 대한 수치해석적 연구 (Study on Prediction of Net Thrust of Multi-Pod-Driven Ice-Breaking Vessel Under Bollard Pull and Overload Conditions According to the Change of Water Depth Using Computational Fluid Dynamics-Based Simulations)

  • 김진규;김형태;김희택;이희동
    • 대한조선학회논문집
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    • 제58권3호
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    • pp.158-166
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    • 2021
  • In this paper, a numerical analysis technique using a body force model is investigated to estimate the available net thrust of multi-pod-driven ice-breaking vessels under bollard pull and overload conditions. To employ the body force model in present flow simulations, drag and thrust components acting on the pod unit are calculated by using Propeller Open Water (POW) test data. The available net thrusts according to the direction of operation are evaluated in both bollard pull and overload conditions under deep water. The simulation results are compared with the model test data. The available net thrusts, calculated by the present analysis for ahead operating modes at 3~6 knots which are typical speeds of the target vessel in arctic field, are agreed well with the model test results. It is also found that the present result for astern operating mode appears approximately 6 % larger than the model test result. In addition, the available net thrusts are calculated under the both operating conditions accompanied by shallow water effects, and the main cause of the difference is studied. Based on the result of the present study, it is confirmed that the body force model can be applied to the performance evaluation of multi-pod propulsion system and the main engine selection in early design stage of the vessel.

Effects of future climate conditions on photosynthesis and biochemical component of Ulva pertusa (Chlorophyta)

  • Kang, Eun Ju;Kim, Kwang Young
    • ALGAE
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    • 제31권1호
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    • pp.49-59
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    • 2016
  • Ulva pertusa, a common bloom-forming green alga, was used as a model system to examine the effects of elevated carbon dioxide (CO2) and temperature on growth and photosynthetic performance. To do this, U. pertusa was grown under four temperature and CO2 conditions; ambient CO2 (400 μatm) and temperature (16℃) (i.e., present), elevated temperature only (19℃) (ET; i.e., warming), elevated CO2 only (1,000 μatm) (EC; i.e., acidification), and elevated temperature and CO2 (ET and EC; i.e., greenhouse), and its steady state photosynthetic performance evaluated. Maximum gross photosynthetic rates (GPmax) were highest under EC conditions and lowest under ET conditions. Further, ET conditions resulted in decreased rate of dark respiration (Rd), but growth of U. pertusa was higher under ET conditions than under ambient temperature conditions. In order to evaluate external carbonic anhydrase (eCA) activity, photosynthesis was measured at 70 μmol photons m−2 s−1 in the presence or absence of the eCA inhibitor acetazolamide (AZ), which inhibited photosynthetic rates in all treatments, indicating eCA activity. However, while AZ reduced U. pertusa photosynthesis in all treatments, this reduction was lower under ambient CO2 conditions (both present and warming) compared to EC conditions (both acidification and greenhouse). Moreover, Chlorophyll a and glucose contents in U. pertusa tissues declined under ET conditions (both warming and greenhouse) in conjunction with reduced GPmax and Rd. Overall, our results indicate that the interaction of EC and ET would offset each other’s impacts on photosynthesis and biochemical composition as related to carbon balance of U. pertusa.

Effects of loading conditions and cold joint on service life against chloride ingress

  • Yang, Keun-Hyeok;Mun, Ju-Hyun;Yoon, Yong-Sik;Kwon, Seung-Jun
    • Computers and Concrete
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    • 제22권3호
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    • pp.319-326
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    • 2018
  • RC (Reinforced Concrete) members are always subjected to loading conditions and have construction joints when constructed on a big scale. Service life for RC structure exposed to chloride attack is usually estimated through chloride diffusion test in sound concrete, however the test is performed without consideration of effect of loading and joint. In the present work, chloride diffusion coefficient is measured in concrete cured for 1 year. In order to evaluate the effect of applied load, cold joint, and mineral admixtures, OPC (Ordinary Portland Cement) and 40%-replaced GGBFS (Ground Granulated Blast Furnace Slag) concrete are prepared. The diffusion test is performed under loading conditions for concrete containing cold joint. Investigating the previous test results for 91 days-cured condition and the present work, changing diffusion coefficients with applied stress are normalized considering material type and cold joint. For evaluation of service life in RC continuous beam with 2 spans, non-linear analytical model is adopted, and service life in each location is evaluated considering the effects of applied stress, cold joint, and GGBFS. From the work, varying service life is simulated under various loading conditions, and the reduced results due to cold joint and tensile zone are quantitatively evaluated. The effect of various conditions on diffusion can provide more quantitative evaluation of chloride behavior and the related service life.