• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.27-40
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• 1990

In recent years, tissue antigens and enzymes that will serve as phenotypic markers for malignant cells are becoming increasingly important as diagnostic aids. This study was undertaken to investigate the specific activities of these enzymes in DMBA-induced rat submaxillary gland carcinogenesis. One hundred and twenty Sprague-Dawley rats about 100 gms of body weight were used. In experimental group, DMBA pellet (5mg) was implanted into right submaxillary gland and sham operation was performed into left gland to serve as control. The animals were sacrificed every three weeks up to 15 weeks. Submaxillary glands were excised on both sides and enzyme assays for ${\gamma}-glutamyl$ transpeptidase (GGT), 5'-Nucleotidase, Ornithine decarboxylase(ODC) and Acetyl-Co A carboxylase were carried out biochemically. The obtained results were as follows ; 1. In control group, there was no significant weight change of submaxillary gland, while experimental group, weight was increased remarkably about 7-fold at 15th week since DMBA implantation. 2. In control group, there was no change in specific activities of enzymes during the experimental period. 3. GGT activity was rapidly increased reaching a peak of 1.766${\pm}$0.082units/mg of DNA, 8-fold greater than that of onset. 4. 5'-Nucleotidase activity was increased reaching a peak of $362.1{\pm}53.2{\mu}moles/mg$ of DNA at 9th week. 5. ODC activity was rapidly increased, reaching a peak of 26.2${\pm}$4.8nmoles/mg of DNA at 9th week and quickly returned to that of control at 15th week. 6. Acetyl-Co A carboxylase activity was rapidly increased earlier than other enzymes, reaching a peak of 0.178${\pm}$0.013units/mg of DNA at 6th week and quickly declined to the control level at 15th week.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.11
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• pp.997-1004
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• 2011

A fault detection algorithm of a charge and discharge system to ensure the safe use of hybrid electric vehicle is proposed in this paper. This algorithm can be used as a complementary way to existing fault detection technique for a charge and discharge system. The proposed algorithm uses a SVDD technique, which additionally utilizes two methods for learning a large amount of data; one is to incrementally learn a large amount of data, the other one is to remove the data that does not affect the next learning using a new data reduction technique. Removal of data is selected by using lines connecting support vectors. In the proposed method, the data processing speed is drastically improved and the storage space used is remarkably reduced than the conventional methods using the SVDD technique only. A battery data and speed data of a commercial hybrid electrical vehicle are utilized in this study. A fault boundary is produced via SVDD techniques using the input and output in normal operation of the system without using mathematical modeling. A fault detection simulation is performed using both an artificial fault data and the obtained fault boundary via SVDD techniques. In the fault detection simulation, fault detection time via proposed algorithm is compared with that of the peak-peak method. Also the proposed algorithm is revealed to detect fault in the region where conventional peak-peak method is never able to do.

• Water for future
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• v.26 no.1
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• pp.93-101
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• 1993

Because of the Keumkangsan-Dam and the Peace-Dam constructed in recent years, it is expected that the peak flood discharge and the peak flood stage at the Hwachun-Dam site have been changed. In this study, two methods were used to simulate and compare the effects of the upstream dam construction on the change of the discharge and the stage. One is the storage function method widely used for the hydrological routing in this country. The other is the DWOPER (Dynamic Wave Operational Model) package developed by the U.S. NWS for the hydraulic routing. Flood routing simulations have been performed on four different scenarios:1) Before the construction of the Keumkangsan-Dam and the peace-Dam, 2) The exclusion of the Keumkangsan-Dam watershed (before the construction of the Peace-Dam), 3) The exclusion of the Keumkangsan-Dam watershed (after the construction of the Peace-Dam), 4) The exclusion of the Peace-Dam watershed. The results of the four test cases from the two methods show that the peak flood discharge and the peak flood stage at the Hwachun-Dam site are reduced due to the construction of the Peace-Dam. From these findings, it is suggested that the operational criteria for the optimal dam-operation of the hwachun-Dam need to be modified.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.1-6
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• 2018

In smart grid an accurate load forecasting is crucial in planning resources, which aids in improving its operation efficiency and reducing the dynamic uncertainties of energy systems. Research in this area has included the use of shallow neural networks and other machine learning techniques to solve this problem. Recent researches in the field of computer vision and speech recognition, have shown great promise for Deep Neural Networks (DNN). To improve the performance of daily electric peak load forecasting the paper presents a new deep neural network model which has the architecture of two multi-layer neural networks being serially connected. The proposed network model is progressively pre-learned layer by layer ahead of learning the whole network. For both one day and two day ahead peak load forecasting the proposed models are trained and tested using four years of hourly load data obtained from the Korea Power Exchange (KPX).

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.11
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• pp.27-32
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• 1999

Metal-ferroelectric-semiconductor devices by susing rapid thermal annealed $LiNbO_3/Si$(100) structures were fabricated and demonstrated nonvolatile memory operations. The estimated field-effect electron mobility and transconductance on a linear region of the fabricated FET were about $600cm^2/V{\cdot}s$ and 0.16mS/mm, respectively. The ID-VG characteristics of MFSFET's showed a hysteresis loop due to the ferroelectric nature of the $LiNbO_3 films. The drain current of the on state was more than 4 orders of magnitude larger than the off state current at the same read gate voltage of 0.5V, which means the memory operation of the MFSFET. A write voltage as low as ${\pm}3V$, which is applicable to low power integrated circuits, was used for polarization reversal. The ferroelectric capacitors showed no polarization degradation up to $10^{10}$ switching cycles with the application of symmetric bipolar voltage pulse (peak-to-peak 6V, 50% duty cycle) of 500kHz.

• Journal of IKEEE
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• v.9 no.1 s.16
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• pp.40-46
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• 2005

A process variation compensation method called 'regulated drain detection' is proposed. This paper also shows the how this newly invented method is applied to a typical differential PLL. The proposed RDD(regulated drain detection) and its PLL application has been designed and tested in a $0.18{\mu}m$ 1-poly 3-metal plain digital process so that its stable performance and higher yield can be proven. The implemented PLL aimed to the operation range of 80MHz - 240MHz and the total die size is only $0.18{\mu}m$ including the internal loop filter. The tracking jitter characteristics is measured to less than 150 peak-to-peak under l.8V supply rail.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.230-235
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• 2009

We have conducted an experimental study to analyze characteristics of the wheel profile wear and an influence of the wheel flange wear on the vehicle's vibration characteristics. In experiment with EMU, wheel profile wear is severe at the beginning of the commercial operation. In this stage, the variations of the wheel dimension parameters and equivalent conicity is changed rapidly. Along with a mileage of the test vehicle, the wear of the wheel flange is increased and also the vibration level of the car-body is increased. The peak-peak mean value of the body vibration is estimated as good level, but the level is approached at the limit of the good level as mileage increases. Especially, the peak-peak maximum value of the body vibration shows the distinct increase of vibration level.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1550-1551
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• 2006

An L-band linear accelerator system for e-beam sterilization is under design for bio-technology application. The klystron-modulator system as RF microwave source has an important role as major components to offer the system reliability for long time steady state operation. A PFN line type pulse generator with a peak power of 71.5-MW, $7{\mu}s$, 285 pps is required to drive a high-power klystron. The high power pulse transformer has a function of transferring pulse energy from a pulsed power source to a high power load. The pulse transformer producing a pulse with a peak voltage of 275 kV is required to produce 30-MW peak and 60 kW average RF output power at the frequency of 1.3-GHz. We have designed the high power pulse transformer with 1:13 step-up ratio. The peak and average power capability is 71.5-MW (275 kV, 260 A at load side with $7{\mu}s$ pulse width) and 130 kW, respectively. In this paper, we present a system overview and initial design results of the high power pulse transformer.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.314-316
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• 2006

06년 하절기 최대부하시 EMS SE를 통한 최대부하 계통을 취득하여 PSS/E file로 변환하여 발전기 및 송변전선비 등 실제계통의 운전상황을 확보하였다. 이를 토대로 '06년도 하절기 실계통 전력계통의 특성을 도출하고, 조류계산 및 안정도 검토 등을 통해 금년 상반기에 수립된 하계운영방안의 적정성을 평가해 보았다. 이러한 분석을 통해 계획단계의 최적화된 방안도출을 도모하고 분석내용은 향후 전력계통 안정운영을 위한 자료로 활용할 수 있을 것이다.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.87-90
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• 2002

This paper describes design technique of switched-capacitor 1V delta-sigma modulator. To solve the incomplete switching operation at low voltage, bootstrapping technique is used. For PMOS input pair of 1V operational amplifier, simple common mode level down technique is used. Designed 2nd order single loop modulator has an oversampling ratio of 64 and obtains a peak SNR of 71dB, a dynamic range of 73 dB with the power consumption of 350uW at 1V power supply.