• 한국안전학회지
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• 제21권5호
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• pp.46-52
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• 2006

The purpose of this paper is to investigate the removal efficiency of fine dusts as the configuration condition of machinery and equipments in Clean Room and to analyze the flowing behaviors of fine dusts as the layout of Clean Room. The layout of the Clean Room was classified into side layout type, 2 center line type and center concentration type layout, and the flow rates used in this research were 0.22m/s, 0.44m/s and 0.80m/s. Dust removal efficiency as layout change was decreased 37% for side layout type, 31% for 2 center line type and 20% for center concentration type layout at the flow rate of 0.22m/s, compared with the state without machinery and equipments in Clean Room. The efficiency was decreased 42% for side layout type, 22% for 2 center line type and 8% for center concentration type layout at the flow rate of 0.44m/s, and decreased 20% for side layout type, 18% for 2 center line type and 10% for center concentration type layout at the flow rate of 0.80m/s. According to the result of dust removal behavior, $0.3{\mu}m,\;1{\mu}m\;and\;3{\mu}m$ dust except for $5{\mu}m$ showed the higher change of the behavior in side layout type than in center concentration type layout due to the change of air flow. It was confirmed that removal behavior depends on the layout of machinery and equipments as the dust size decreases.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1917-1926
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• 2018

In view of the current state of the reserves of electric energy generated resources and the share of electric motors in electricity consumption, many researches and studies related to efficiency in electric motors are being made. The presented work is related to the Axial Flux Permanent Magnet Synchronous Motor (AF-PMSM), which has recently undergone significant work based on the development of magnet and motor technology. In this study, a novel AF-PMSM was designed analytically through Finite Element Method (FEM) which can be started by connecting to a line such as an asynchronous motor in a transient state and can operate with high efficiency and power factor after synchronization in steady state without the need for an expensive motor drive. According to the obtained FEM results, a design with an efficiency class of IE4 of 5.5 kW shaft power, a 4 poles motor was obtained. As a result, economic calculations indicate that the extra cost of the designed Line start AF-PMSM with respect to the asynchronous motor is rapidly compensated by energy saving due to a more efficient operation, especially constant speed operations. As a result of the analysis obtained, the targeted values are reached. For induction motors and radial flux permanent magnet synchronous motors, a good alternative motor that can operate with high efficiency and power factor has been obtained.

• Animal Bioscience
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• 제36권3호
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• pp.417-428
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• 2023

Objective: Few studies have genetically monitored chickens over time, and no research has been conducted on ducks. To ensure the sustainable management of key duck breeds, we used microsatellite markers to monitor Brown Tsaiya ducks over time genetically. Methods: The second, fourth, sixth to eighth generations of the Brown Tsaiya duck selected for feeding efficiency and control lines were included in this study to investigate the genetic variations, effective population size, population structure and the differentiation between populations over time with 11 microsatellite markers derived from Brown Tsaiya duck. Results: The results showed there were a slight decrease in the genetic variations and an increase in within-population inbreeding coefficient (F_IS) in both lines, but no consistent increase in F_IS was observed in each line. The effective population size in the second and eighth generations was 27.2 for the selected line and 23.9 for the control line. The change in allele richness showed a downward trend over time, and the selected line was slightly lower than the control line in each generation. The number of private alleles (N_p) in the selected line were higher than in the control line. Moderate differentiation was observed between the second and eighth generations in the selected line (F_ST = 0.0510) and the control line (F_ST = 0.0606). Overall, differentiation tended to increase with each generation, but genetic variation and structure did not change considerably after six generations in the two lines. Conclusion: This study provides a reference for poultry conservation and helps to implement cross-generation genetic monitoring and breeding plans in other duck breeds or lines to promote sustainable management.

• 한국수정란이식학회지
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• 제19권3호
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• pp.201-208
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• 2004

본 연구에서는 clonal cell lines을 효율적으로 확립할 수 있는 방법을 제시하기 위하여 배양액 내에 catalase와 $\beta$ME 첨가가 clonal cell line 확립 효율에 미치는 영향을 검토하였다. 임신 50일령의 암퇘지에서 얻은 태아섬유아세포를 2회 passage한 후 동결 보관하였다가 실험에 이용하였다. 단일세포를 catalase나 $\beta$ME가 첨가된 배양액이 들어 있는 96-well dish로 옮겨 배양하였다. 단층이 형성된 세포는 4-well dish로 옮겨주어 배양하였으며, 이후 2회 이상 passage가 가능한 세포를 clonal line이 확립된 세포로 판정하였다. 실험 1에서 clonal line 확립효율에 미치는 catalase와 $\beta$ME의 효과를 검토하기 위하여 세포를 100ng/$m\ell$) catalase와 100nM $\beta$ME가 첨가된 DMEM액 내에서 배양하여 clonal line 확립효율을 검토하였다. $\beta$ME 첨가 시 clonal line 확립효율이 8.3%로 대조구의 3.2%에 비해 유의적으로 높게 나타났다.(P<.0.05). 그러나 catalase 첨가 시(3.6%)에는 대조구와 차이가 없었다. 실험 2에서 catalase 농도(0, 10, 100, 1,000ng/$m\ell$)에 따른 clonal line 확립효율을 검토하였다. 대조구에 비하여 모든 처리구에서 clonal line 확립 효율에 대한 첨가효과가 없었다(0-2.6%). 실험 3에서 $\beta$ME 농도(0, 10, 100, 1,000 nM)에 따른 clonal line 확립효율을 검토하였다. 100 nM의 $\beta$ME 첨가 시 clonal line 확립 효율이 9.4%로 대조구 및 타 처리구(0-l.6%)보다 유의적으로 높게 나타났다(P<0.05). 본 연구 결과 배양액 내 catalase 첨가는 확립효율에 영향을 미치지 않지만, 100nM의 $\beta$ME 첨가로 clonal cell line의 확립효율을 향상시킬 수 있는 것으로 나타났다.

• 에너지공학
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• 제20권4호
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• pp.330-337
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• 2011

난방장치로서 통상 가스 및 기름보일러가 많이 사용되어진다. 본 연구는 기존의 가스 및 기름 보일러에 의한 난방방식과 달리 밀폐된 X-L 파이프 내에 특수 제작된 전열선을 삽입하여 그 전열선에 전압을 인가함으로써 X-L 파이프 내 열매체의 온도를 상승시켜 난방하는 방법에 관한 것이다. 특수 제작된 전열선의 가닥수와 인가전압을 변화시켜 X-L 파이프 보일러의 특성과 발열 메카니즘을 파악하였다. 또한 X-L 파이프 보일러와 가스 및 기름보일러와의 난방비용을 객관적인 자료에 근거하여 서로 비교를 함으로써 그 경제성을 평가하였다. 그 결과 X-L 파이프 보일러는 기름(보일러등유)보일러의 28%, 가스(천연가스)보일러의 58%의 비용으로 난방이 가능함을 확인하였다.

• 한국전자파학회논문지
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• 제23권5호
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• pp.624-631
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• 2012

본 논문은 Guanella의 1:1 transmission-line transformer와 harmonic filtering 방식을 이용한 13.56 MHz 고효율 전류 모드 D급(CMCD) 전력증폭기를 제안한다. 출력 정합 네트워크에 기존의 D급 전력증폭기의 부하 네트워크를 변형하여 harmonic filtering 방식을 포함시킴으로써 낮은 2차와 3차 고조파 특성을 얻었다. 제작된 CMCD 전력증폭기는 13.56 MHz의 CW 입력 신호를 사용하여 측정하였을 때, 13.4 dB의 전력 이득을 가지며, 44.4 dBm의 출력에서 84.6 %의 높은 PAE 특성을 나타내었다. 같은 출력에서 2차 3차 고조파는 각각 -50.3 dBc와 -46.4 dBc를 나타냈다.

• 전기학회논문지P
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• 제58권2호
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• pp.154-157
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• 2009

In order to give handiness to the management of the existing street lighting system which is based on the one way communication and to reduce the maintenance cost, the power line communication filter in the two way communication which is based on the CDMA communication and power line communication was improved and accordingly the stability of the communication performance was improved. Also, the efficiency of existing street lighting system and smart street lighting system was evaluated as Visual studio system. As a result, when the number of street lights is 10,000, the hours of daily work fell 50% and the number of necessary maintenance staff decreased 40%. Compared to the maintenance costs of the existing street lighting system, it could be expected to have the cut costs of almost 100 million won a year on the basis of 60 switch board and 1,200 street lights.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.961_962
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• 2009

A novel, two-inductor, interleaved power-factor-corrected (PFC) boost converter that exhibits voltage-doubler characteristic when it operates with a duty cycle greater than 0.5 is introduced. The voltage-doubler characteristic of the proposed converter makes it quite suitable for universal-line (90~265VRMS) PFC applications. Because the proposed PFC boost rectifier operates as a voltage doubler at low line, its low-line range efficiency is greatly improved compared to that of its conventional counterpart. The performance of the proposed PFC rectifier was evaluated on an experimental 300W PFC prototype.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1001-1006
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• 2004

Selection of optimal railway line is taken into consideration include of the purpose of railway, geographical features and facility of management. This study performed opinions of specialists, checking of industrial environment, analysis of bid guideline to select the optimal line and executed AHP method to make quality model and choose weight factors. Therefore, this study executed about six categories which are the efficiency of transportation, facility of planning and construction, economical efficiency, coincidency of planning, the civil appeal and environmental standards, connection with system, and indicated the differences of other method by analyze into specific factors of each categories.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.832-835
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• 2003

By using vacuum in-line driving and photoluminescence measuring method, we have observed the electrical and optical characteristics of the vacuum in-line sealing technology and analyzed the effect of the base vacuum level before filling the plasma gas. In the case of base vacuum level of $1{\times}10^{-3}$torr, the firing voltage of a 2-inch diagonal PDP panel was ranged from 310 to 345V depending on the plasma gas pressure of 200 to 300torr and luminous efficiency was ranged from 0.0227 to 0.0367 lm/W depending on the input voltage level of 330 to 225V. While, in the case of $1{\times}10^{-6}$, the characteristics were significantly improved. As a results, the firing voltage was ranged from 295 to 318V and luminous efficiency was from 0.0278 to 0.0451 lm/W.