• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.108-117
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• 1985

The process of conveying of soil with the open auger to cover the seed completly with less power was reviewed by theoretical analysis. The power efficiency, the reasonable range of RPM of the open auger and the velocity of soil conveying to the direction of the shaft are examined to establish the extent of characteristics of the open auger performance. The results of theoretical analysis and application of similitude are as follows: 1. It is possible to predict the power efficiency by the following equation; ${\eta}_p={\frac{P_n}{P_g}}=({\frac{{\omega}_s}{{\omega}_a}}){\cdot}tan{\gamma}{\frac{mg}{(F_mcos{\alpha}+F_scos{\gamma})}}$ 2. The reasonable range of the revolutions per minute of the open auger was presented as follow to cover completely with less power ; $$\frac{4d(L_a-L_i){\cdot}V_w}{{\pi}(D_o^2-D_s^2){\cdot}r{\cdot}{\frac{{\omega}_s}{{\omega}_a}}{\cdot}tan{\gamma}}{{\leq_-}}{\omega}_a{{\leq_-}}({\frac{{\omega}_a}{{\omega}_s}}){\sqrt{\frac{g}{r}}}$$ 3. The velocity of soil conveying to the direction of the auger shaft may be calculated by the equation; $V_h=({\frac{{\omega}_s}{{\omega}_s}})V_a{\cdot}tan{\gamma}$ 4. The factor of RPM was more important than other factors on the power efficiency.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.301-303
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• 2001

In this paper we present a Capacitor Charging Power Supply (CCPS) using a series-resonant three-level inverter topology to improve voltage regulation and use semiconductor switches having low blocking voltage capability such as MOSFETs. This inverter can be operated with two modes, Full Power Mode (FPM) and Half Power Mode (HPM). In FPM inverter supplies the high frequency step up transformer with full DC-link voltage and in HPM with half DC-link voltage. HPM switching method will be adopted when CCPS output voltage reaches the preset target value and operates in refresh mode-charge is maintained on the capacitor. In this topology each semiconductor devices blocks a half of the DC-link voltage[2]. A 15kW, 30kV CCPS has been built and will be tested for an electric precipitator application. The CCPS operates from an input voltage of 500VDC and has a variable output voltage between 10 to 30kV and 1kHz repetition rate at 44nF capacitive load [3]. A resonant frequency of 67.9kHz was selected and a voltage regulation of $0.83\%$ has been achieved through the use of half power mode without using the forced cut off the switch current [1]. The theory of operation, circuit topology and test results are given.

• Nuclear Engineering and Technology
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• v.19 no.2
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• pp.115-121
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• 1987

A high voltage stabilization system for the SNU 1.5MV Tandem Van do Graaff accelerator was set up and its operational characteristics were examined and optimized. The optimum parameters of beam transport system were experimentally determined, and under the proper condition the accelerated proton beam current of 350nA was obtained at the target chamber. Without the high voltage stabilization the observed magnitude of voltage fluctuation was $\Delta$V/ V=5.2$\times$10$^{-3}$ without ion beam and 7.2$\times$10$^{-3}$ with ion beam, respectively, and its apparent ripple frequency for voltage fluctuations was about 3Hz or less. Through the optimized operation of the high voltage stabilization system, the terminal voltage fluctuation was reduced to $\Delta$V/V=2.45$\times$10$^{-4}$ and the energy stability with $\Delta$E/E=2.44$\times$10$^{-4}$ was steadily maintained at the 247.3kV terminal voltage, and the stabilization factor was deduced to be 29.4.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.417-418
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• 2006

CATIA V5 is one of the most preferred softwares in product design for domestic and industrial use. But with the development of the IT industry, design data by CATIA V5 can easily be hacked and stolen especially via the internet and through assistance storage medium. The design data could be protected through executive, physical and technical security system. The best way to maintain confidentiality of data from unauthorized access is to have a cryptosystem of the technical security. In this paper, a cryptosystem for the protection of design data was being proposed. The memory contains the file information made by the New and Open function of CATIA V5. No error can be expected even if the file changed before of after the application of Save and Open function, A cryptosystem was constructed in CATIA V5 by inserting crypto algorithm before and after the I/O process. The encryption/decryption algorithm of each function was based on the complex cipher, which applied permutation cipher and transpose cipher. The file security system was programmed in CAA V5 and Visual C++.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.6
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• pp.59-66
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• 1995

The hot electron induced effective channel length modulation (${\Delta}L_{H}$) and HEIP characteristics in PMOSFET's after bidirectional stress are presented. Trapped electron charges in gate oxide and lateral field are calculated from the gate current model, and ${\Delta}L_{H}$(${\Delta}L_{HD},\;{\Delta}L_{HS}$) is calculated using trapped electron charges and lateral field. It has been found that ${\Delta}I_{d}$and ${\Delta}L_{H}$ are more affected by the stress order (Forward-Reverse of Reverse or Reverse-Forward) than the stress direction, and they vary logarithmically with the stress time. In contrast, ${\Delta}V_{t}$ and ${\Delta}V_{pt}$ are more affected by the stress direction thatn the stress order. The correlation between ${\Delta}V_{pt}$ and the stress time can be explanined as the following polynomial functin: ${\Delta}V_{pt}$=AT$^{n}$. It has also been shown that PMOSFET degradation is related with the gate current and the effects of ${\Delta}V_{pt}$ is the most significant.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.350-353
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• 2002

High voltage SiC Schottky barrier diodes with field plate structure have been fabricated and characterized. N-type 4H-SiC wafer with an epilayer of ∼10$\^$15/㎤ doping level was used as a starting material. Various Schottky metals such as Ni, Pt, Ta, Ti were sputtered and thermally-evaporated on the low-doped epilayer. Ohmic contact was formed at the backside of the SiC wafer by annealing at 950$^{\circ}C$ for 90 sec in argon using rapid thermal annealer. Field oxide of 550${\AA}$ in thickness was formed by a wet oxidation process at l150$^{\circ}C$ for 3h and subsequently heat-treated at l150$^{\circ}C$ for 30 min in argon for improving oxide quality. The turn-on voltages of the Ni/4H-SiC Schottky diode was 1.6V which was much higher than those of Pt(1.0V), Ta(0.7V) and Ti(0.7). The voltage drop was measured at the current density of 100A/$\textrm{cm}^2$ showing 2.1V for Ni Schottky diode, 1.45V for Pt 1.35V, for Ta, and 1.25V for Ti, respectively. The maximum reverse breakdown voltage was measured 1100V in the file plated Schottky diodes with 101an thick epilayer.

• Journal of the Korean Society of Tobacco Science
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• v.37 no.1
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• pp.8-17
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• 2015

The purpose of this study is to classify the tobacco names in the world, to investigate the regional distribution of the classified type, and to show origin of names according to the type. The names of tobacco used in this study was 50. The type of tobacco names was classified by the presence or absence of nasal sound(morn) on the first syllable, the Number of syllable, and the structure of consonants and vowels of tobacco names. Type I (Dambago) has the nasal sound on the first syllable. The proportion of Type I(Dambago) was 28%. And the rest(Type I~Type V ; 72%) has no nasal sound. Type II(Tabaco) has three syllables, and its proportion was 20%. Type III(Tabac) has the two syllables and the structure of T+vowels+B+vowels. And its proportion was 30%. Type IV(Tutun) has the two syllables and the structure of T+vowels+T+vowels. And its proportion was 12%. Type V(Duhan) has the two syllables and the structure of D+vowels+H(V)+vowels. And its proportion was 10%. The world's most widely distributed type was Type I(Dambago). regional distribution of the world's tobacco names were clustered by the type. 72% of Type I(Dambago) was distributed in Asia. The etymology of Type I(Dambago) was only 14% Tambaku and the other is not yet known. The etymology of Type I(Dambago) seems to be derived from the Haitian Tambaku(meaning a tobacco pipe). 88% of Type II(Tabaco) and III(Tabac) were distributed in Europe. The etymology of Type II(Tabaco) and Type III(Tabac) were 84% Spanish "Tabaco". 100% of Type IV(Tutun) and V(Duhan) were distributed in Europe. The etymology of Type IV(Tutun) and Type V(Duhan) were 100% Turkish tutun and duhan, respectively. This finding suggests that the etymology of Type I(Dambago) is certainly may be Haitian "Tambaku(meaning a tobacco pipe)".

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.207-210
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• 2001

A fully automated high performance liquid chromatography with column-switching was developed for the simultaneous determination of KR60436, a new reversible proton pump inhibitor, and its active metabolite O-Demethyl-KR60436 from rat plasma samples. Plasma sample (50$\mu$l) was directly introduced onto a Capcell Pak MF Ph-1 column ($10{\times}4$ mm I.D.) where primary separation was occurred to remove proteins and concentrate target Substances Using acetonitrile-Potassium Phosphate (PH 7, 0.1 M) (2 : 8, v/v). The drug molecules eluted from MF Ph-1 column were focused in an intermediate column ($10{\times}2$ I.D.) by the valve switching step. The substances enriched in intermediate column were eluted and separated on a Vydac 218MR53 column ($250{\times}3.2$ I.D.) using acetonitrilepotassium phosphate (pH 7, 0.02 M) (47:53, v/v) at a flow rate of 0.5 ml/min when the valve status was switched back to A position. The method showed excellent sensitivity (detection limit of 2 ng/ml) with small volume of samples ($50{\mu}$l), good precision and accuracy, and speed (total analysis time 24 min) without any loss in chromatographic efficiency. The response was linear ($r^2{\geq}0.797$) over the concentration range of 5-500 ng/ml.

• Journal of Radiation Protection and Research
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• v.22 no.2
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• pp.127-133
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• 1997

In this study an EGS4 simulation code was used to calculate real energy spectrum from measured ${\gamma}$-ray energy spectrum obtained using 2-dimensional radiation monitoring system. As a result, the $39{\times}39$ response matrix was calculated the energy range of 0.1 to 2 MeV which energy interval of 50 keV The real energy spectrum for Co-60 radioisotope was calculated using inverse of response matrix. It was confirmed that the calculated response matrix was useful to the analysis of the measured energy spectrum for the radiation monitoring system.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.471-477
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• 2008

The porcine PRKAG3 (RN) gene encodes the regulatory gamma subunit of adenosine monophosphate-activated protein kinase (AMPK), which is a good candidate gene affecting meat quality. In this study, the effects of two missense mutations A595G (Ile199Val) and G154A (Gly52Ser) in porcine PRKAG3 gene on meat quality traits were studied in M. Longissimus dorsi (LD), M. Semispinalis capitis (SC) and M. Biceps femoris (BF) from different populations of 326 pigs. The PRKAG3 alleles 199I, 199IV, 52S and 52G were identified with PCR-RFLPs and all genotypes - 199I/199I, 199I/199V, 199V/199V, 52S/52S, 52S/52G and 52G/52G - were found. The frequency of V allele was larger than that of I allele in all populations. I allele frequency was zero in Chinese Meishan pigs (population D) especially. G allele frequency was larger than that of S allele in all populations except Large White (population A). Both variations at the PRKAG3 locus significantly affected these meat quality traits. The pork meat quality has not previously been established in Meishan or crosses thereof. The results suggested that generally pH of LD, SC and BF was higher in Meishan pigs than that in other populations. Moreover, Meishan pigs showed higher water-holding capacity and intramuscular fat (IMF), lower water content and water loss percentage compared to other populations in terms of the two variations. The results present here supply new evidence that alleles V199I and G52S at the PRKAG3 locus affect pork meat quality and provide useful information on pork production.