• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1803-1806
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• 2013

Purpose: Carbohydrate antigen (CA) 242 is inversely related to prognosis in many cancers. However, few data regarding CA 242 in esophageal cancer (EC) are available. The aim of this study was to determine the prognostic value of CA 242 and propose an optimum cut-off point in predicting survival difference in patients with esophageal squamous cell carcinoma (ESCC). Methods: A retrospective analysis was conducted of 192 cases. A receiver operating characteristic (ROC) curve for survival prediction was plotted to verify the optimum cuf-off point. Univariate and multivariate analyses were performed to evaluate prognostic parameters for survival. Results: The positive rate for CA 242 was 7.3% (14/192). The ROC curve for survival prediction gave an optimum cut-off of 2.15 (U/ml). Patients with CA 242 ${\leq}$ 2.15 U/ml had significantly better 5-year survival than patients with CA 242 >2.15 U/ml (45.4% versus 22.6%; P=0.003). Multivariate analysis showed that differentiation (P=0.033), CA 242 (P=0.017), T grade (P=0.004) and N staging (P<0.001) were independent prognostic factors. Conclusions: Preoperative CA 242 is a predictive factor for long-term survival in ESCC, especially in nodal-negative patients. We conclude that 2.15 U/ml may be the optimum cuf-off point for CA 242 in predicting survival in ESCC.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.526-531
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• 1997

기존의 발전소 피로수명 평가 프로그램들은 On-Line Fatigue Analysis애 중점을 두고 개발되어 운전 초기부터 Transient모니터링 프로그램이 설치되는 시점까지의 Transient 데이터가 확보되지 않은 오래된 발전소의 경우 전 수명기간 동안의 피로수명 계산에 어려움이 많다. 따라서 본 연구에서는 특별한 경우를 제외하고는 Off-Line 계산을 하는 것이 경제적이고 피로수명 평가에 문제가 되지 않는다고 판단하여 Transient 모니터링을 용해 Transient 종류를 파악하고 이를 데이터베이스화 한뒤 충분한 시간을 가지고 Transient 이력 과 응력데이타를 조합하여 CUF를 계산하는 등 프로그램 기능의 모듈화를 시도하여 필요한 기능을 지속적으로 보완 개발해 나갈 수 있도록 하였다. 본 Software는 국내 원전이 Transient Counting이나 피로분석의 전산화와 관련한 경험이 부족하고 또 외국 프로그램을 도입하여 사용하기에는 과거 데이터가 부족하여 활용에 어려움이 많을 것을 고려하여 기존의 수작업에 의한 Fatigue Evaluation 의 불편함을 보완하고 On-Line Analysis의 필요성과 Off-Line Analysis외 경제성을 적절히 조합하여 현재 발전소 환경에서 가장 적절히 사용할 수 있도록 개발 을 추진하였고 향후 필요한 기능은 지속적으로 보완함으로써 발전소 수명관리에 유용하게 사용될 것이다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.484-489
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• 2014

Three phase PWM(Pulse Width Modulation) converter of the small-scale wind power system is able to charge battery under the rated wind speed regions. However, it is impossible to control output power of converter at the over win speed region because back-EMF(Electro Motive Force) of PMSG(Permanent Magnet Synchronous Generator) is higher than the battery terminal voltage of PMSG is reduced. However, the cut-off wind speed exists although battery charging algorithm is implemented by flux weakening control method. Therefore, this paper performs analysis of other factors which affects limitation wind speed. The validity of the analysis are verified through simulation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.92-97
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• 2011

Vehicle lightings are very important for safe driving during night time. Since the eye recovery time after an exposure to oncoming headlights would take after several seconds, the aiming point of vehicle head lamps have to pass safety requirements. Despite the fact that vehicle inclination is variable with vehicle load conditions, the head lamps aiming point is usually fixed at a constant position which is set by car manufacturer. Consequently, vehicle head lamps under varying load conditions often make people in the opposing vehicle uncomfortable, and even worse, can cause an accident. This paper presents an active vehicle lighting mechanism to automatically adjust its aiming point, or cut-off line, in order to compensate the change in vehicle inclination resulting from load variations. The effectiveness of the proposed method is demonstrated through a set of simulations and experiments with a real vehicle.

• KSBB Journal
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• v.10 no.2
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• pp.126-130
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• 1995

A membrane gas sensor was developed for the measurement of ethanol concentration during acetic acid fermentation. The fermentation broth including ethanol was permeated through the silicone membrane by synthetic air as a carrier gas and was detected by a semiconductor gas sensor. The optimum conditions of membrane gas sensor were 20m1/min of flow rate and 0.5mm of membrane thickness. In acetic acid fermentation, an on-line measurement of ethanol concentration was conducted by the proposed membrane gas sensor and then the on-line sensor signal, was compared with the result of off-line analysis by gas chromatography. As a result, a correlated response over the range of $0∼70g/\ell$ was shown between membrane gas sensor and gas chromatography and this use of membrane gas sensor was experimentally ascertained for the monitoring and control of bioprocess like acetic acid fermentation.