• Journal for History of Mathematics
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• v.24 no.3
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• pp.59-76
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• 2011

Starting from a collection V as a model which satisfies the axioms of NBG, we call the elements of V as sets and the subcollections of V as classes. We reconstruct the G$\ddot{o}$del's proof of the consistency of GCH and AC with the axioms of Zermelo-Fraenkel set theory by using Mostowski-Shepherdson mapping theorem, reflection principles in Tarski-Vaught theorem and Montague-Levy theorem and the fact that NBG is a conservative extension of ZF.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.373-376
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• 2006

The ring rolling design for a large-scale Ti-6Al-4V alloy ring was performed with a calculation method and FEM simulation. The ring rolling design includes geometry design and optimization of process variables. The calculation method was to determine geometry design such as initial billet and blank size, and final rolled ring shape. A commercial FEM code, SHAPE was used to simulate the effect of process variables in ring rolling on the distribution of the internal state variables such as strain, strain rate and temperature. In order to predict the forming defects during ring rolling, the process-map approach based on Ziegler's instability criterion was used with FEM simulation. Finally, an optimum process design to obtain sound Ti-6Al-4V rings without forming defects was suggested through combined approach of Ziegler's instability map and FEM simulation results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.281-287
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• 2002

The stochiometric composition of AgGaS$_2$ polycrystal source materials for the AgGaS$_2$/GaAs epilayer was prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns it was found that the polycrystal AgGaS$_2$ has tetragonal structure of which lattice constant a$\sub$0/ and c$\sub$0/ were 5.756 ${\AA}$ and 10.305 ${\AA}$, respectively. AgGaS$_2$/GaAs epilayer was deposited on throughly etched GaAs(100) substrate from mixed crystal AgGaS$_2$ by the Hot Wall Epitaxy (100) system. The source and substrate temperature were 590$^{\circ}C$ and 440$^{\circ}C$ respectively. The crystallinity of the grown AgGaS$_2$/GaAs epilayer was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for AgGaS$_2$/GaAs epilayer at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by ${\alpha}$ : 8.695${\times}$10$\^$-4/ eV/K, and ${\beta}$ = 332 K. From the photocurrent spectra by illumination of polarized light of the AgGaS$_2$/GaAs epilayer, we have found that crystal field splitting ΔCr was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pain are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.78-88
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• 2021

The annual consumption of fishery products, particularly sea squirt (Halocynthia roretzi), per person has steadily increased in South Korea. However, the quantitative risk of Vibrio parahaemolyticus following intake of sea squirt has not been analyzed. This study focuses on quantitative predictions of the probability of consuming sea squirt and getting of V. parahaemolyticus foodborne illness. The prevalence of V. parahaemolyticus in sea squirt was evaluated, and the time spent by sea squirt in transportation vehicles, market displays, and home refrigerators, in addition to the temperature of each of these, were recorded. The data were fitted to the @RISK program to obtain a probability distribution. Predictive models were developed to determine the fate of V. parahaemolyticus under distribution conditions. A simulation model was prepared based on experimental data, and a dose-response model for V. parahaemolyticus was prepared using data from literature to estimate infection risk. V. parahaemolyticus contamination was detected in 6 of 35 (17.1%) sea squirt samples. The daily consumption quantity of sea squirt was 62.14 g per person, and the consumption frequency was 0.28%. The average probability of V. parahaemolyticus foodborne illness following sea squirt consumption per person per day was 4.03 × 10^-9. The objective of this study was to evaluate the risk of foodborne illness caused by Vibrio parahaemolyticus following sea squirt consumption in South Korea.

• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1841-1847
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• 2008

Vibrio vulnificus is a causative agent of serious diseases in humans, resulting from the contact of wound with seawater or consumption of raw seafood. Several studies aimed at detecting V. vulnificus have targeted vvh as a representative virulence toxin gene belonging to the bacterium. In this study, we targeted the rpoS gene, a general stress regulator, to detect V. vulnificus. PCR specificity was identified by amplification of 8 V. vulnificus templates and by the loss of a PCR product with 36 non-V. vulnificus strains. The PCR assay had the 273-bp fragment and the sensitivity of 10 pg DNA from V. vulnificus. SYBR Green I-based real-time PCR assay targeting the rpoS gene showed a melting temperature of approximately $84^{\circ}C$ for the V. vulnificus strains. The minimum level of detection by real-time PCR was 2 pg of purified genomic DNA, or $10^3$ V. vulnificus cells from pure cultured broth and $10^3$ cells in 1 g of oyster tissue homogenates. These data indicate that real-time PCR is a sensitive, species-specific, and rapid method for detecting this bacterium, using the rpoS gene in pure cultures and in infected oyster tissues.

• Journal of Astronomy and Space Sciences
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• v.25 no.2
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• pp.87-100
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• 2008

A total of 792 CCD images of V523 Cas were obtained on four nights of Jan. 2003 with the bvri CCD photometric system attached to a 61cm reflector of Sobaeksan Optical Astronomy Observatory (SOAO). The 17 standard stars in the images were used to establish transformation relations between our bvri system and the standard Johnson-Cousins BVRI system. We derived the tentative equations of transformation between two photometric systems as follows; V=v-0.0689(B-V)+0.0063, B-V=1.3197(b-v)-0.1733, V-R=0.9210(v-r)-0.1309, R-I=0.8892(r-i)-0.1055. Using these equations standard V magnitudes and their color indexes (B-V, V-R, R-I) for 57 stars in the field of the image were determined.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.2
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• pp.315-323
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• 1997

The sing1e crystal of cadmium sulfide was grown by vertical sublimation method. The lattice constants of CdS single crystal by extrapolation method are $a_0=4.139\AA$ and $c_0=6.719\AA$, respectively. The $Cu_2$S/CdS solar cell was fabricated using the single crystal of cadmium sulfide and the CuCl solution. The light- to- dark JV cross over effect of the $Cu_2$S/CdS solar cell was measured after annealing for 2 minutes at $250^{\circ}C$ in air atmosphere. The values of Voc, Jsc, Vop, FF, and efficiency are 0.40 volt, $4.2mA/\textrm{cm}^2$, 0.31 volt, $3.8mA/\textrm{cm}^2$, 0.68 and 3.8 %, respectively. The spectral response of the solar cell shows the peaks at 498 nm (2.49 eV) and 585 nm (2.12 eV).

• Annals of Clinical Neurophysiology
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• v.5 no.2
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• pp.192-196
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• 2003

The Lateral dorsal cutaneous branch of sural nerve (LDCB) is a terminal sensory branch of lower extremities. It can be injured frequently in peripheral nerves. However, the normal data of each component of nerve conduction study (NCS) of were not studied at this time. The Nerve Conduction Study of LDCB adults were assessed for amplitude, area, duration and nerve conduction velocity (NCV) in normal fifty. We also evaluated how age, sex and dexterity affect the various components of NCS. The Mean amplitude of LDCB was $9.45{\pm}1.93{\mu}V$, area was $4.05{\pm}0.55{\mu}V/s$, duration was $1.50{\pm}0.13s$, and NCV was $37.9{\pm}3.09m/s$, respectively. The amplitude of right was $10.1{\mu}V$ in men, $8.65{\mu}V$ in women. The area of right was $3.83{\mu}V/s$ in less than 40 years and $4.24{\mu}V/s$ in older than 40 years. The areas of left was $3.86{\mu}V/s$ in less than 40 years and $4.30{\mu}V/s$ in older than 40 years. The NCV was 39.0 m/s in less than 40 years and 36.7 m/s in older than 40 years. All of above differences were statistically significant. There were no statistically significant differences between right and left NCS. Normal data of LDCB could be applicable in peripheral neuropathy or nerve injury.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1533-1535
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• 2000

The design and fabrication technologies of pulse power reversely switched-on dynistor have been developed 1200V/120kA pulse power reversely switched-on dynistor device have been designed by analytically and numerically using commercial modeling S/W The important characteristics of reversely switched-on dynistors are breakover voltage $V_{BO}$, commutative peak voltage before steady state $V_m$, on-state voltage in steady state $V_o$, turn-off time $t_q$, dV/dt capability.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.2
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• pp.168-175
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• 2017

In this paper, a 5V small-area NMOS-diode eFuse OTP memory cell is proposed. This cell which is used in PMICs consists of a 5V NMOS transistor and an eFuse link as a memory part, based on a BCD process. Also, a regulated voltage of V2V ($=2.0V{\pm}10%$) instead of the conventional VDD is used to the pull-up loads of a VREF circuit and a BL S/A circuit to obtain a wider operational voltage range of the eFuse memory cell. When this proposed cells are used in the simulation, their sensing resistances are found to be $15.9k{\Omega}$ and $32.9k{\Omega}$, in the normal read mode and in the program-verify-read mode, respectively. Furthermore, the read current flowing through a non-blown eFuse is restricted to $97.7{\mu}A$. Thus, the eFuse link of a non-blown eFuse OTP memory cell is kept non-blown. The layout area of the designed 1kb eFuse OTP memory IP based on Dongbu HiTek's BCD process is $168.39{\mu}m{\times}479.45{\mu}m(=0.08mm^2)$.