• 제목/요약/키워드: Studying effect

검색결과 919건 처리시간 0.023초

서울지역에 있어서 거주공간의 미생물의 오염 및 이들에 대한 제어에 관하여 (Microbial Contamination in the Atmosphere in Seoul Metropolitan Area and its Control)

  • 이배함;유관희;김영자;이복권;전영미;오재욱
    • 미생물학회지
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    • 제17권2호
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    • pp.65-71
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    • 1979
  • On studying of microbes and appearance frequency which are floating around dwelling space and life environments in Seoul area, the results are summarized as follows ; 1. 1931 strains of 29 bacteria are isolated in dwelling spaces, Among them, there are Staphylococcus aureus, S. anthracis which are pathogenic to human beings. 2. In fungi, 76 strains of 13 species are isolated. That of highest frequency is confirmed to be Aspergillus which is pathogens of Aspergillosis (one of a group of diseases of animals and human being caused by various species of Aspergillus). The places, where the number of kinds and the frequency of appearances have been observed highest, are coffee shops, lunch counters and office rooms, while factory districts are of far lower level than expected. 3. 0.1% $HgCl_2$, Leasking oil, and Telephone disinfectant were better than any other in fungicidal effect.

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고속전철 주행시 이선현상 모델링 방법에 따른 전도성 노이즈 해석 (Analysis of conducted noise on modeling methods for loss of contact during traction of high-speed rail vehicle)

  • 김재문;김양수;장진영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전기설비전문위원
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    • pp.72-75
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    • 2008
  • The Electromagnetic Interference(EMI) in railway applications is largely due to doing the power conversion for traction and Auxiliary system on the Highspeed Electric Multiple Unit-400X(HEMU-400X). In order to research on EMI in railway applications, it were included how much the HEMU-400X generates it and it has an effect on the equipments of electric system which resulted from Power Line Disturbance (PLD) phenomenon by the loss of contact during its running. In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

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계통전압(154kV)이 소내수전 무효전력에 미치는 영향 연구 (A Study on the effect on reactive power transmitted to the power station by Voltage (154kV) of Power System)

  • 전규남;장문성;남궁혁;정해정;안주훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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    • pp.314-315
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    • 2007
  • As a section of electric power system linked with Kepco was changed, the decrease in qulity of the electric power transmitted to the Hapcheon hydraulic power station occurred. The actual state bring about the overheating and capability decline of electricity accommodation equipment. From now, let's improve the efficiency on the maintenance of generating equipment by studying about the cause and the method for this problem.

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방제(方劑)에서 행인(杏仁)의 역할에 관한 문헌적 고찰 (The Role of Armeniacae Amarum Semen in Herbal Formula)

  • 변성희;김한균;지선영;이병욱;김상찬
    • 대한한의학방제학회지
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    • 제11권2호
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    • pp.29-40
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    • 2003
  • Armeniacae Amarum Semen was well-known as a theraputic agent of asthma by flowing downward of qi and moistening of lung in Oriental Medicine. But there are many other effect in Armeniacae Amarum Semen such as, loosening the bowel to relieve constipation, removing stagnation of qi and food, dispersing accumulation of pathogen, parasiticide. We have been studying what the meaning of Armeniacae Amarum Semen in herbal formula and usage of Armeniacae Amarum Semen is.

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2차원 관내 유동에서 불활성 기체 제거과정의 직접 수치 해석 (DIRECT NUMERICAL SIMULATION OF IMMISCIBLE GAS BUBBLE DISPLACEMENT IN 2D CHANNEL)

  • 신승원
    • 한국전산유체공학회지
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    • 제12권3호
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    • pp.41-46
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    • 2007
  • Dynamic behavior of immiscible gas bubble attached to the wall in channel flow plays very important role in many engineering applications. Special attention has been paid to micro direct methanol fuel cell(${\mu}$DMFC) where surface tension becomes dominant factor with minor gravitational effect due to its reduced size. Therefore, displacement of $CO_2$ bubble generating on a cathode side in ${\mu}$DMFC can be very difficult and efficient removal of $CO_2$ bubbles will affect the overall machine performance considerably. We have focused our efforts on studying the dynamic behavior of immiscible bubble attached to the one side of the wall on 2D rectangular channel subject to external shear flow. We used Level Contour Reconstruction Method(LCRM) which is the simplified version of front tracking method to track the bubble interface motion. Effects of Reynolds number, Weber number, advancing/receding contact angle and property ratio on bubble detachment characteristic has been numerically identified.

Oxidation Stability of PAO Oils Determined by Differential Scanning Calorimetry

  • Shim, Joosup;Cho, Wonoh;Chung, Keunwo
    • Tribology and Lubricants
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    • 제12권1호
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    • pp.36-41
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    • 1996
  • The suitability of a pressure differential scanning calorimetry (PDSC) in monitoring the quality of synthetic base fluids has been investigated using polyalphaolefin (PAO) oils as an example. Induction period meassured at 170, 180 and 19$0^{\circ}C$, and 3.53 MPa oxygen pressure was applied to characterize their oxidation stability. The PDSC method has proven to be simple and repeatable and requires only small sample size for testing. More importantly, it can be applied in differentiating the oxidation performance quality of PAO oils and is versatile enough for use in studying kinetic aspects of PAO oil oxidation which include the effect of temperature and antioxidant concentration. Additionally, the method appears to correlate well with a rotary bomb oxidation test (RBOT).

전차선-팬터그래프 사이의 이선현상에 따른 전원외란이 보조전원장치에 미치는 영향 (Effect of power line disturbance on loss of contact between contact wire and pantograph)

  • 김재문;김양수;장진영;김윤명
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.179-181
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    • 2008
  • In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

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의료기관 종사자들의 임파워먼트와 직무만족 및 조직몰입이 이직의도에 미치는 영향 (The Impacts of Working in the Hospital Empowerment, Job Satisfaction and Organizational Commitment Turnover Intention)

  • 장효강
    • 보건의료산업학회지
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    • 제6권1호
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    • pp.65-75
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    • 2012
  • The purpose of this study is to provide information to Efficient utilization of human resources management by studying the factors influencing the turnover intention of employees working in the Hospital. The study, the area of medical institutions located in more than 30 hospital-grade medical workers engaged in the collection of data aimed at the September 2010 and October 1 days and 1, 794 were used for the analysis, data processing and analysis package, SPSS 18.0 was used. The findings are as follows: First, the study found that age, job position had a significant and negative effect on turnover intentions. The turnover intention rates were highest among nursing staffs, followed by medical technicians and healthcare supporters and then administrators. Secondly, high degree of autonomy, job skills recognition and less job satisfaction in a positions have been identified to affect the significant. It also has turned out that job suitability and emotional commitment have influenced the turnover intentions.

Design charts for yield acceleration and seismic displacement of retaining walls with surcharge through limit analysis

  • Aminpoor, Mohamad Mahdi;Ghanbari, Ali
    • Structural Engineering and Mechanics
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    • 제52권6호
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    • pp.1225-1256
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    • 2014
  • Calculating the seismic displacement of retaining walls has an important role in the optimum design of these structures. Also, studying the effect of surcharge is important for the calculation of active pressure as well as permanent displacements of the wall. In this regard, some researchers have investigated active pressure; but, unfortunately, there are few investigations on the seismic displacement of retaining walls with surcharge. In this research, using limit analysis and upper bound theorem, permanent seismic displacement of retaining walls with surcharge was analyzed for sliding and overturning failure mechanisms. Thus, a new formulation was presented for calculating yield acceleration, critical angle of failure wedge, and permanent displacement of retaining walls with surcharge. Also, effects of surcharge, its location and other factors such as height of the wall and internal friction angle of soil on the amount of seismic displacements were investigated. Finally, designing charts were presented for calculating yield acceleration coefficient and angle of failure wedge.

A study of internal wave influence on OTEC systems

  • Shi, Shan;Kurup, Nishu V.;Halkyard, John;Jiang, Lei
    • Ocean Systems Engineering
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    • 제3권4호
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    • pp.309-325
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    • 2013
  • Ocean Thermal Energy Conversion (OTEC) systems utilize the temperature difference between the surface water and deep ocean water to generate electrical energy. In addition to ocean surface waves, wind and current, in certain locations like the Andaman Sea, Sulu Sea and the South China Sea the presence of strong internal waves may become a concern in floating OTEC system design. The current paper focuses on studying the dependence of the CWP hydrodynamic drag on relative velocity of the flow around the pipe, the effect of drag amplification due to vortex induced vibrations and the influence of internal waves on the floating semi and the cold water pipe integrated OTEC system. Two CWP sizes are modeled; the 4m diameter pipe represents a small scale prototype and the 10m diameter pipe represents a full commercial size CWP. are considered in the study.