• Journal of The Korean Astronomical Society
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• v.54 no.1
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• pp.1-8
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• 2021

We report X-ray timing and spectral properties of the pulsar PSR J0205+6449 measured using NuSTAR and Chandra observatories. We measure the pulsar's rotation frequency ν = 15.20102357(9) s-1 and its derivative $\dot{\nu}=-4.5(1){\times}10^{-11}\;s^{-2}$ during the observation period, and model the 2-30 keV on-pulse spectrum of the pulsar with a power law having a photon index Γpsr = 1.07 ± 0.16 and a 2-30 keV flux F2-30 keV = 7.3±0.6 × 10-13 erg cm-2 s-1. The Chandra 0.5-10 keV data are analyzed for an investigation of the pulsar's thermal emission properties. We use thermal and non-thermal emission models to fit the Chandra spectra and infer the surface temperature T∞ and luminosity Lth of the neutron star to be T∞ = 0.5 - 0.8 MK and Lth = 1 - 5 × 1032 erg s-1. This agrees with previous results which indicated that PSR J0205+6449 has a low surface temperature and luminosity for its age of 800-5600 yrs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.739-742
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• 2000

Nanostructured ZnS thin films were grown on the slide glass substrate by the chemical bath deposition using an aqueous so1ution Of ZnSO$_4$and CH$_3$CSNH$_2$at 95$^{\circ}C$. The average grain sizes of the ZnS thin film estimating from the Debye-Scherrer formula are 4.8 nm. The optical transmittance edge of the ZnS thin films (4.0 eV) was shifted to the shelter wavelength compared with that of the bulk ZnS (3.67 eV) due to the quantum size effects. The ZnS thin films showed a strong photoluminescence intensity and a sharp emission band from 410 to 480 nm 3t room temperature. The PWHM of photoluminescence peak was about 40 nm. For the viloet(410 nm) and blue(480 nm) emission of the ZnS thin films, the temperature dependence can be described by an Arrhenius equation with an activation energy of 168 and 157 meV, respectively.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.442-448
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• 2013

Lactic acid bacteria (LAB) are a representative group of probiotics and used in many fermented foods and beverages. Several recent studies have shown that LAB are present in makgeolli which is a traditional Korean alcoholic beverage. However, most LAB are intolerant of more than 6% (v/v) alcohol concentrations. For this reason, alcohol-tolerant LAB are isolated from kimchi, makgeolli and nuruk using alcohol containing selective media. After being cultured in MRS broth containing 13% (v/v) alcohol, the two strains which showed the highest increasing O.D values, were finally selected. As results of 16S rRNA gene sequencing and biochemical characterization using an API kit, the two species were identified as Pediococcus acidilactici K3 and S1. In addition, the identified two strains produced bacteriocins against Staphylococcus aureus. When compared with the P. acidilactici type strain, the two selected strains possessed two to three time higher growth on 12-13% (v/v) alcohol containing MRS broth. The viability of P. acidilactici K3 and S1 when inoculated in makgeolli and stored at $10^{\circ}C$ did not decrease through a period of one month indicating that the selected strains can be used for LAB containing makgeolli.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.584-589
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• 1995

To select new useful plants with antibacterial activity, ninety five sample of eighty different species of wild plants were collected, and extracted with methanol. Antibacterial activity of the methanol extracts was tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Vibrio parahaemolyticus. The methanol extracts from Artemisia capillaris, Hemistepta lyrata, Youngia japonica, Prunella vulgaris, Lamium amplexicaule and Juniperus chinensis was effective against all bacterial strains tested, and eight methanol extracts including Ixeris dentata, Gnaphalium affine, Chelidonium majus and Spiraea prunifolia exhibited the antibacterial activity against at least 3 bacterial strains. Methanol extracts from leaf of Syringa vulgaris, Drava nemorosa and clove of Erythronium japonicum showed a selective antibacterial activity against two gram negative bacteria, V. parahaemolyticus, and B. subtilis, respectively. With investigations on antibacterial activity against a certain bacterial strains tested, metahnol extracts from clove of Erythronium japonicum, Spiraea prunifolia, leaf and twig of Camelia japonica, and Drava nemorosa showed strongest activities against B. subtilis, S. aureus, E. coli, and V. parahaemolyticus, respectively. Nine methanol extracts based on the results were successively fractionated with n-hexane, chloroform, ethyl acetate and water portions, which were examined antibacterial activity against B. subtilis and V. parahaemolyticus. Among the all fractions tested, chloroform fractions of Hemistepta lyrata showed strongest antibacterial activity against both B. subtilis (17mm) and V. parahaemolyticus (29 mm). Chloroform fractions of Youngia japonica, n-hexane fractions of Artemisia capillaris, Iexeris dentata and Prunella vulgaris, and ethyl acetate fraction of leaf and twig of Camelia japonica showed relatively a strong antibacterial activity. On the other hand, Juniperus chinensis and Equisetum arvense was distributed to all fractions except for water fraction.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1091-1093
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• 1999

This paper discusses the surveying of a power transmission line using Real Time Kinematic(RTK) GPS technology. The use of RTK provides users with an accurate position at the moment in time. Application result of a 765kV transmission line surveying proved to be more accurate and efficient than using a traditional EDM (Electro-magnetic distance measurement) method. More, decrease in numbers of trees cut down which is a major cause of public discontents was achieved. Improvements in doing a surveying of a power transmission line using GPS is expected in the future.

• Journal of IKEEE
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• v.22 no.4
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• pp.1218-1221
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• 2018

This paper presents a low-power 0.6-V 10-bit 200-kS/s double rail-to-rail successive approximation register (SAR) analog-to-digital converter (ADC). The proposed scheme allows input signal with 4 times power which is compared with conventional one by applying proposed rail-to-rail scheme, and that improves signal-to-noise ratio(SNR) of NTV SAR ADCs. The prototype was designed using 65-nm CMOS technology. At a 0.6-V supply and $2.4-V_{pp}$ (differential) and 200-kS/s, the ADC achieves an SNDR of 59.87 dB and consumes 364.5-nW. The ADC core occupies an active area of only $84{\times}100{\mu}m^2$.

• Journal of Internet of Things and Convergence
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• v.2 no.1
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• pp.35-40
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• 2016

One of the next generation of automotive V2V communication technology is a core technology for next-generation ITS as a technique used for communications between the vehicle. Looking at the existing V2V communication using the pseudonym certificate authentication service structure to meet the security requirements for privacy protection. Since the issuance of multiple certificates when needed authority in issuing and managing to use the pseudonym certificate issued once and it takes a lot of time. In this paper, we present the method utilizing a vehicle ID to meet the security requirements for the privacy protection without the use of a pseudonym certificate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1741-1746
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• 2012

This paper introduces a new DC-DC voltage multiplier using a Dickson's charge pump and a modified voltage doubler. The voltage obtained from a conventional Dickson's chrage pump was reused for accelerating the voltage multiplication and the architecture of the proposed voltage multiplier would not decrease the device reliability of DMOS. The proposed 6-stage voltage multiplier generates about 33V with 3V voltage source. To evaluate the proposed voltage multiplier, simulations were performed with Magna DMOS technology. The simulated voltage multiplication agrees well with a theoretical value, therefore, this paper introduces a new fast voltage multiplier with minimum devices.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.252-260
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• 2018

Energy, a critical input, is to be efficiently managed via waste heat recovery and energy reuse for the economic viability of a process industry. In particular, cement manufacture demands a huge quantum of energy, for the necessary reactions. Huge amounts of hot effluent gases are generated. Energy recovery from these waste gases is an area that is of contemporary research interest. Now, about 75% of total heat recovery takes place in the riser of the suspension pre-heater system. This article deals with the hydrodynamic and heat transfer aspects of riser typically used in the cement industry. An experimental apparatus was designed and fabricated with provision for the measurement of gas pressure and solid temperatures at different heights of the riser. The system studied was air - chalcopyrite taken in different particle sizes. Acceleration length ($L_A$) determined at different parametric levels was fitted to an empirical correlation: $L_A/d_t=4.91902(d_p/d_t)^{0.10058}(w_s/w_g)^{-0.11691}(u_g{\mu}_g/d_t^2g{\rho}_g)^{0.28574}({\rho}_p/{\rho}_g)^{0.42484}$. An empirical model was developed for Nusselt number as a function of Reynolds and Prandtl numbers using regression analysis: $Nu=0.40969(Re_p)^{0.99953}(Pr)^{0.03569}$.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.153-157
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• 1995

The effect of low concentrations of ethanol(3∼7%, v/v) in culture broth as an antibacteriaB agent against Vibrio parahaemolyticus was tested at -20, 5, 35, 45 and 5%. Increasing concentrations of ethanol progressively inhibited initial growth of t: parahaemelyticus at 35$^{\circ}C$. Growth occured at 5% ethanol, but only after a prolonged lag period. At 7% ethanol, the number of viable cells of V parahae-molyticus declined during incubation. Culture broth containiilg 3∼7% ethanol was inoculated with 106∼107'cells/uu of V Parahaemolyticus and incubated at low temperatures(5$^{\circ}C$, -20$^{\circ}C$) and high tem-peratures(45$^{\circ}C$, 50$^{\circ}C$). In the presence of 5 or 7ft of ethanol, the viability in the cells incubated at high temperatures decreased rapidly. Rate of death increased with increasing concentration of etha-nol.