• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.9
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• pp.817-821
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• 2001

In this paper, a new learning methodology for kernel methods that results in a sparse representation of kernel space from the training patterns for classification problems is suggested. Among the traditional algorithms of linear discriminant function, this paper shows that the relaxation procedure can obtain the maximum margin separating hyperplane of linearly separable pattern classification problem as SVM(Support Vector Machine) classifier does. The original relaxation method gives only the necessary condition of SV patterns. We suggest the sufficient condition to identify the SV patterns in the learning epoches. For sequential learning of kernel methods, extended SVM and kernel discriminant function are defined. Systematic derivation of learning algorithm is introduced. Experiment results show the new methods have the higher or equivalent performance compared to the conventional approach.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.67-76
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• 2006

This paper describes the analysis method to define the system specification for conducted EMI environment and verification method to evaluate the conducted EMI performance. Conducted EMI environment is characterized by the electrical power subsystem which is mainly issued by the switching circuit noise, common ground impedance coupling. To define and control these EMI problems, EMI assesment through system analysis are preceded at the early design phase and then EMI reduction methods are applied during the unit/system development phase. System EMC should be carefully controlled and designed in the consideration of EMC safety margin and its performance is fully evaluated at the whole development period.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.541-541
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• 2008

반도체 소자가 차세대 초미세 공정 기술 도입의 가속화를 통해 고속화 및 고집적화 되어 감에 따라 나노(Nano) 크기의 회로 선폭 미세화를 극복하고자 최적의 CMP (Chemical Mechanical Polishing) 공정이 요구되어지고 있다. 이처럼 CMP 공정이 반도체 제조 공정에 적용됨으로써 공정 마진 확보에 진일보 하였으나 CMP 장비의 공정 조건, 슬러리의 종류, 연마패드의 종류 등에 의해 CMP 성능이 결정된다. 특히 슬러리는 연마 공정의 성능에 중요한 영향을 미치는 요인이다. 고가의 슬러리가 차지하는 비중이 40% 이상을 넘고 있어 슬러리 원액의 소모량을 줄이기 위한 연구들이 현재 활발히 진행되고 있다. 본 연구에서는 새로운 연마제의 특성을 알아보기 위해 탈이온수(De-ionized water; DIW) 에 $CeO_2$, 연마제를 첨가한 후 분산시간에 따른 연마 특성과 AFM, EDX, XRD, TEM분석을 통해 그 가능성을 알아보았다.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.200-201
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• 2006

현재상용화 되어 있는 AC PDP는 Ne, Xe 혼합가스를 주로 사용한다. Xe gas의 비율이 높아짐에 따라 PDP의 휘도와 효율은 상승하지만 그와 동시에 방선 전압도 함께 상승하여 이 분야의 연구가 요구된다. 그래서 우리는 Ne gas를 버퍼 가스의 사용하괴 Xe gas를 0${\sim}$15%, Kr gas를 0${\sim}$50% 비율의 첨가하여 패널의 방전 개시 전압, 방선 유지 전압, 방선 마진, 휘도, 효율을 측정하였다. 그 결과 방선 개시 전압이 같고 효율이 각각 2.93[Im/w], 3.23[Im/w]인 Xe10%+Kr20%, Xe5%+Kr40%와 같은 최적의 3원 가스조합을 찾아내었다. 또한 Xe gas와 Kr gas의 합이 40%일 때 효율이 가장 좋아지는 것을 알 수 있었다.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.132-139
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• 2013

Liquid-propellant rocket engines are widely used all over the world, thanks to their high performances thrust, in particular high thrust-to-weight ratio. The sucess rate of the launching of the liquid propulsion is similar to the solid one even though it has more complex mechanical system. In general, liquid propulsion is seemed as a mature technology, the requirements of a renewed interest for space exploration has led to the development of a family of new engines, with more design margins, simpler to use and to produce associated with a wide variety of thrust and life requirements.

• YAKHAK HOEJI
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• v.56 no.4
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• pp.217-221
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• 2012

To determination of antioxidant substance homoorientin, from Phyllostachys bambusoides leaves, the ultrasonic extraction and HPLC on-line $ABTS^+$ screening method were empolyed. Also, the various experimental variables such as the frequency and time of ultrasonic system were investigated and homoorientin was extracted efficiently at the low frequency 35 kHz and the extraction time 60 min. The values were positive peak 1574.71 (relative area, 23.67%) and negative peak 6924.34 (relative area, 1.23%), respectively. This HPLC on-line $ABTS^+$ screening method was rapid and efficient to search for antioxidants from natural products. These results will provide a database for investigating the constituents of natural products and the resources of pharmaceutical and cosmetic products.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.217-225
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• 2010

A Through-Bulkhead Initiation Module(TBIM) works as the shock-wave generated by the detonation of donor explosive transmits to acceptor explosive. In order to estimate the minimum thickness of the bulkhead of TBIM, the structural stress of TBIM housing is calculated via modeling analysis, and which shows a sufficient margin in strength as the minimum thickness is bigger than 0.1 mm. The free surface velocity at the metal to explosive interface is measured using VISAR to determine the optimal thickness of bulkhead. The shock pressure is calculated from the measured free surface velocity, and the probability of TBIM with respect to the thickness of bulkhead is estimated by comparing the sensitivity of acceptor explosive with it.

• Nuclear Engineering and Technology
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• v.15 no.4
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• pp.219-228
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• 1983

The blowdown history of the TMI-2 accident up to the isolation of the relief valve associated with a small break LOCA is reviewed briefly. An analysis is made to determine what instruments should be added in the core in order to prevent core damage in the case of the TMI-2 accident. With the added instruments a procedure is presented on how to predict the uncovered level of the core and how to calculate operator time margin. Sample calculations are done for the TMI-2 accident to determine the uncovered level and operator time margin. Finally, the map to show the uncovered level of the core and operator time margin is drawn with measurable parameters by the above methods.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.374-378
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• 2011

This study was performed to evaluate enhanced effect of fermented Galgeun tang (GGT) and Ssanghwa tang (SHT) on the anti-platelet aggregation. Platelet aggregation assay was performed In vitro using human platelet rich plasma(PRP) and In vivo using SD-rat plasma by platelet aggregometer. Pharmacodynamic parameters, $E_{max}$ and $EC_{50}$, were calculated using Winnolin. SD-rats administered 1 g/kg of oriental medicine every 12 hr for 8 days. Platelet aggregation was measured by optical method with collagen inducer (4 ${\mu}g$/ml). In In vitro anti-platelet study, $EC_{50}$ of GGT-A was lower than that of GGT-con about 79.13 ${\mu}g$/ml. And $EC_{50}$ of SHT-A and SHT-B was lower than that of SHT-con about 122.73 and 110.15 ${\mu}g$/ml, respectively. It is assumed that fermented GGT and SHT were more effective than original medicine. In multiple administration study, anti-platelet effect was significantly increased both GGT and SHT. Fermented GGT and SHT were more effective than original herbal medicine on anti-platelet aggregation.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.361-366
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• 2011

Traditional herbal medicinal preparation Bojungikki-tang (BJT) is well-known herbal medicine used as tonic. We fermented Bojungikki-tang using nine lactic acid bacteria strains and discovered two remarkably increased compositions from the fermented BJTs using HPLC/DAD analysis. HPLC/DAD-guided fractionation of the increased compositions followed by structure identification using NMR and MS identified liquiritigenin and isoliquiritigenin. These bioconversion compositions were quantitatively analyzed using HPLC-DAD. Liquiritigenin contents were highest in BJTs fermented with L. amylophilus (1.91 mg/g) and L. fermentum (1.89 mg/g), which were increased by 20-fold compared to BJT (0.09 mg/g). Isoliquiritigenin contents were highest in BJTs in fermented with L. plantarum (0.19 mg/g) and L. fermentum (0.19 mg/g), which were increased by 19-fold compared to BJT (0.01 mg/g).