• 한국축산식품학회지
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• 제21권2호
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• pp.163-168
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• 2001

This study was conducted to analyze the errors occurred between standard plate count(SPC) and Bactometer, Malthus, Bactoscan and to investigate correlation coefficient(r) between SPC and each equipments for the purpose of making new calibration curve. Correlation coefficients of three different types of equipments to SPC value were 0.71, 0.81, 0.84 respectively(n=287) and that of three types of equipments were 0.71∼0.82 relatively low. In raw milk, correlation coefficients of three types of equipments of SPC were in the range of 0.67∼0.73 below 3.0${\times}10^4$(CUF/ml) of bacterial number, and those between the three types of equipments were 0.68∼0.72. Between 3.0${\times}10^4$∼5.0${\times}10^5$(CFU/ml) of bacterial number, correlation coefficients of the three different types of equipments were 0.71∼0.81. and those between the three different types of equipments were 0.64∼0.77. Over 5.0${\times}10^5$(CFU/ml), correlation coefficient of the three types equipments were 0.66∼0.83 and those between them were 0.70∼0.85 respectively. The error of the three different types equipments to SPC value was significantly high, 37∼53% of them was under 50% of error range, and in case of raw milk less than 3.0${\times}10^4$ of bacterial number, 44∼67% of them showed over 100% of error.

• 한국식품영양과학회지
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• 제29권4호
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• pp.624-628
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• 2000

측백에 함유 된 히노키티올의 천연 보존료로서의 이용 가능성을 검토하고자 측백 히노키티올 추출물을 식빵 제조시 이용하여 self-life 연장효과 및 품질특성을 조사하였다. 측백에 함유된 히노키 티올은 수증기 증류로 추출했을 때 측백잎에서 12.06mg/100gdldjt고 측백열매 꼬투리에서 13.78mg/100g이었다. 측백 히노키티올 추출물은 식방의 저장 중 수분이나 pH에는 큰 영향 을 주지 못하였으나, 세균 중식 및 곰팡이 생성에는 억제효과를 보였다. 측백잎 50g 추출물 (히나키티올 함량 6.03mg)을 첨가한 식빵은 저장 2일까지 세균이 전혀 자라지 못하였으며 세균수가 104CUF/g 수준에 도달하는데 4일 걸렸다. 또한 곰팡이 생성은 대조구가 저장 3일 째에 관찰되었으나 측백잎 50g 추출물을 첨가한 것은 5일째 관찰되었다. 식빵의 관능적 품 질은 측백 히노키티올 추출물 첨가로 인하여 그다지 영향을 받지 않았다. 이러한 결과는 식 빵 제조시 식빵 제조시 히노키티올 추출물을 이용하면서 식빵의 shelf-life을 연장시킬 수 있음을 보여 주었다.

• 전력전자학회논문지
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• 제25권3호
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• pp.213-218
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• 2020

In this study, we propose a control algorithm to reduce the unbalanced characteristics of a three-phase system power caused by the unbalanced load of the AC electric railway. Then, we verify its performance through the design of a power compensator and experiments applying it. Like electric railway systems, a Scott transformer is applied, and the load and single-phase back-to-back converters are connected to the M-phase and T-phase outputs. The back-to-back converter monitors the difference in active power between the unbalanced loads in real-time and compensates for the power by using bidirectional characteristics. The active power is performed through PI control in the synchronous coordinate system, and DC link overall voltage and voltage balancing control are controlled jointly by M-phase and T-phase converters to improve the responsiveness of the system. To verify the performance of the proposed power compensation device, an experiment was performed under the condition that M-phase 5 kW and T-phase 1 kW unbalanced load. As a result of the experiment, the unbalance rate of the three-phase current after the operation of the power compensator decreases by 58.66% from 65.04% to 6.38%, and the excellent performance of the power compensator proposed in this study is verified.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.423-435
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• 2022

In this article, we present torsion-bending analysis of a composite FGM beam with an open section, according to the advanced and refined theory of 1D / 3D beams based on the 3D Saint-Venant's solution and taking into account the edge effects. The (initially one-dimensional) model contains a set of three-dimensional (3D) displacement modes of the cross section, reflecting its 3D mechanical behaviour. The modes are taken into account depending on the mechanical characteristics and the geometrical form of the cross-section of the composite FGM beam. The model considered is implemented on the CSB (Cross-Section and Beam Analysis) software package. It is based on the RBT/SV theory (Refined Beam Theory on Saint-Venant principle) of FGM beams. The mechanical and physical characteristics of the FGM beam continuously vary, depending on a power-law distribution, across the thickness of the beam. We compare the numerical results obtained by the three-beam theories, namely: The Classical Beam Theory of Saint-Venant (Classical Beam Theory CBT), the theory of refined beams (Refined Beam Theory RBT), and the theory of refined beams, using the higher (high) modes of distortion of the cross-section (Refined Beam Theory using distorted modes RBTd). The results obtained confirm a clear difference between those obtained by the three models at the level of the supports. Further from the support, the results of RBT and RBTd are of the same order, whereas those of CBT remains far from those of higher-order theories. The 3D stresses, strains and displacements, obtained by the present study, reflect the 3D behaviour of FGM beams well, despite the initially 1D nature of the problem. A validation example also shows a very good agreement of the proposed models with other models (classical or higher-order beam theory) and Carrera Unified Formulation 1D-beam model with Lagrange Expansion functions (CUF-LE).

• Journal of Chest Surgery
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• 제42권4호
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• pp.473-479
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• 2009

배경: 역행성자가혈액충전(RAP)은 체외순환으로 인한 과도한 혈희석을 예방하여 심장수술과 관련된 수혈량을 줄일 수 있는 유용한 방법으로 알려져 있으나 그 효과에 대한 반론도 여전하다. 저자들은 RAP의 혈액보존효과를 분석하고 보조적 수단으로서 자가수혈과, 초여과법의 유용성을 알아보고자 하였다. 대상 및 방법: 2005년 1월부터 2007년 12월까지 심폐기를 사용한 단독 관상동맥우회수술을 시행한 117명의 환자를 대상으로 하였다. 평균나이는 63.9$\pm$9.1세(범위 36$\sim$83세), 남여 성비는 83 : 34였고 RAP군은 62명, 대조군은 55명이었다. RAP는 체외순환 시작 전 동맥 및 정맥라인을 통해 정질성 충전액이 배액되도록 하였다. 초여과법은 체외순환 중 시행하는 고전적방법과, 체외순환 직후 시행하는 변형법을 적용하였다. 동종적혈구의 수혈기준은 적혈구용적량 20% 미만으로 하였다 결과: 79예(67.5%)에서 수술 중 자가수혈을 시행하였고 채혈량은 평균 142.5$\pm$65.4 mL (범위 30$\sim$320 mL)였다. 체외순환 중 동종적혈구 수혈은 47예(40.2%)에서 시행되었으며 평균 수혈량은 404.3$\pm$222.6 mL였다. 수혈의 위험인자는 체표면적(OR 0.01, 95% CI 0.00$\sim$0.63, p=0.030)과 심폐기 가동시간(OR 1.04, 95% CI 1.01$\sim$1.08, p=0.019)이었다. RAP는 수혈빈도를 감소시키는 효과는 없었지만(34.5% vs 45.2%, p=0.24), 수혈량은 통계적으로 의미있게 감소하였고(526.3$\pm$242.3 mL vs 321.4$\pm$166.3 mL, p=0.001) 자가수혈과 초여과법을 병합 적용할 경우 누진적으로 수혈량 감소효과가 있는 것으로 나타났다(한가지; 600.0$\pm$231.0 mL, 두가지; 533.3$\pm$264.6 mL, 세가지; 346.7$\pm$176.7 mL, 네가지; 300.0$\pm$146.1 mL, p=0.002). 결론: RAP는 체외순환 중 동종적혈구 수혈빈도를 감소시키지는 못했지만 수혈량은 의미있게 감소시키는 효과가 있었고, 자가수혈과 초여과법은 추가적인 수혈량 감소효과를 보였다. 체외순환 중 수혈빈도를 감소시키기 위해서는 수혈기준이 되는 적혈구용적량을 낮추고 정질성 수액의 투여를 제한하는 등의 적극적 노력이 필요할 것으로 생각된다.