• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.175-179
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• 2005

To develop a high efficiency plant regeneration system from in vitro cultures of strawberry, cv. Yeobong, petiole and leaf explants were cultured on MS basal medium containing a combination of 0.5 mg/L IBA and 3.2 mg/L kinetin or zeatin or benzyl amino purine (BAP) for 6 weeks, and leaf explants with dark pretreatment for a week ($T_1$), 2 weeks ($T_2$), and 4 weeks ($T_3$) were cultured on medium supplemented with 0.5 mg/L IBA and 3.2 mg/L zeatin under 16 hr photoperiod for 6 weeks. Shoot organogenesis was observed from the greenish calli containing minimal anthocyanin formed at proximal cutting edges of the leaf explant (57%) when cultured adaxial side on the medium, whereas was directly formed from a cutting edges of petiole explant (6.3%). Frequency of callus formation and shoot organogenesis at large size of leaf explant ($1.0{\sim}1.5\;cm^2$) was higher than small size ($0.5{\sim}1.0\;cm^2$), and dark pretreatment significantly improved the frequency of leaf explants that produced calli and shoots. The maximum frequency (87%) for shoot organogenesis was obtained from the leaf explants that transferred to a 16 hr photoperiod condition after the initial 4 weeks dark period. The improved frequency (87%) in comparision with control without dark pretreatment (27%). When the shoots were transferred to 1/2 MS basal medium, formed roots with 20 d of culture. The rooted plants were subsequently transferred to the pots and to the field.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.159-166
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• 2009

The purpose of this study was to develop and automatic gait event detection algorithm using single accelerometer which is attached at the top of the shoe. The sinal vector magnitude and anterior-posterior(x-axis) directional component of accelerometer were used to detect heel strike(HS) and toe off(TO), respectively. To evaluate proposed algorithm, gait event timing was compared with that by force plate and kinematic data. In experiment, 7 subjects performed 10 trials level walking with 3 different walking conditions such as fast, preferred & slow walking. An accelerometer, force plate and 3D motion capture system were used during experiment. Gait event by force plate was used as reference timing. Results showed that gait event by accelerometer is similar to that by force plate. The distribution of differences were spread about $22.33{\pm}17.45m$ for HS and $26.82{\pm}14.78m$ for To and most error was existed consistently prior to 20ms. The difference between gait event by kinematic data and developed algorithm was small. Thus it can be concluded that developed algorithm can be used during outdoor walking experiment. Further study is necessary to extract gait spatial variables by removing gravity factor.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.131-139
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• 1998

$CdS_{0.67}Se_{0.33}$ single crystal was grown by vertical sublimation method of closed tube physical vapour deposition. The (0001) growth plane of oriented single crystals was confirmed from the back-ref1ection Laue patterns. From the Hall effects by van der Pauw method, the as-grown $CdS_{0.67}Se_{0.33}$ single crystals were found to be n-type semiconductors. The mobility appeared to be decreased by lattice scattering at temperature range from 150K to 293K and by impurity scattering at temperatures ranging from 30K to 150K In order to explore its applicability in photoconductive cells, we measured the ratio of photo-current to dark-current (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time respectively. The results indicated that for the samples annealed in Cu vapour the photoconductive characteristics are best. We obtained sensitivity of 0.99, the value of pc/de of $1.84{\times}10^{7}$, the MAPD of 323mW and the rise and decay time of 9.3 ms and 9.7 ms, respectively.

• Journal of Ecology and Environment
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• v.44 no.2
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• pp.72-80
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• 2020

Background: Antibiotics are widely used to treat animals from infections. After fertilizing, antibacterials can remain in the soil while adversely affecting the soil microorganisms. The concentration of oxytetracycline (OTC) in the soil and its effect on the soil microbial community was assessed. To assess the impact of OTC on the soil microbial community, it was added to the soil at concentrations of 50, 150, and 300 mg kg^-1 and incubated for 35 days. Results: The concentration of OTC added to the soil decreased from 150 to 7.6 mg kg^-1 during 30 days of incubation, as revealed by LC-MS. The deviations from the control values in the level of substrate-induced respiration on the 5th day of the experiment were, on average, 26, 68, and 90%, with OTC concentrations at 50, 150, and 300 mg kg^-1, respectively. In samples with 150 and 300 mg kg^-1 of OTC, the number of bacteria from the 3rd to 14th day was 2-3 orders of magnitude lower than in the control. The addition of OTC did not affect the fungal counts in samples except on the 7th and 14th days for the 150 and 300 mg kg^-1 contaminated samples. Genes tet(M) and tet(X) were found in samples containing 50, 150, and 300 mg kg^-1 OTC, with no significant differences in the number of copies of tet(M) and tet(X) genes from the OTC concentration. Conclusions: Our results showed that even after a decrease in antibiotic availability, its influence on the soil microbial community remains.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.149-158
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• 2006

Objectives : This study was carried out to characterize the 'Kaolinitum' used as mineral medicine before and after physical and chemical manipulation. Methods : The mineralogy of the original raw kaolinitumes with different localities was identified by X-ray diffraction analysis. The concentrations of major, minor and trace elements of samples, furthermore, measured by the X-ray fluorescence spectrometer (XRF) and inductively coupled plasma-mass spectrometer (ICP-MS). In order to understand the variety of kaolinitum after thermal treatment, the differential thermal analysis (DTA) and the thermo-gravimetric analysis (TGA) were carried out. Results : According to the result of X-ray diffraction analysis, the kaolinitumes are composed ofcalcite, alunite and quartz. Si and Al are the major ions and heavy metals such as Cd, Cr, Pb, Zn, As, Ni and Cu are included in the kaolinitumes as trace ions. The concentration of these metals in the samples decreased after physical and chemical manipulation. The weight of kaolinitum was also decreased at $500^{\circ}C$ and about $700^{\circ}C$during experiment of TGA. Conclusion : The results of this study can be used to provide the scientific basis of the medical usage of kaolinitum.

• Journal of the Semiconductor & Display Technology
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• v.6 no.4
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• pp.29-32
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• 2007

Zinc gallate, $ZnGa_2O_4:Mn^{2+}$ co-doped with different concentrations of $Mg^{2+}$ (0.001- 0.5 mol%) was prepared by solid state synthesis method. These compositions were investigated for their photoluminescence and cathodoluminescence properties. The optimized composition $Zn_{0.990}Mg_{0.005}Ga_2O_4:Mn_{0.005}$ shows higher luminescence intensity compared to the parent phosphor. The intense green emission peak was found at 504 nm. The $Mg^{2+}$ doping does not affect much the decay time. It remains <10 ms for these compositions which make them potential candidate for application in TV screens.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.373-378
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• 2005

[ $Zn(BH_4)_2$ ] ($8.4\;wt\%$ theoretical hydrogen storage capacity) powders have been successfully synthesized by mechanochemical reaction from mixtures of $ZnCl_2$ and $NaBH_4$ powders in a 1:2 molar ratio in different times. $$ZnCl_2\;+\;2NaBH_4\rightarrow\;Zn(BH_4)_2\;+\;2NaCl\;(1)$$ $Zn(BH_4)_2$ powders were characterized by X-ray diffractometry(XRD), and Furier Transform Infrared spectrometry(FT-IR). The thermal stabilities of $Zn(BH_4)_2$ powders were studied by Differential scanning calorimetry(DSC), Thermogravimetry analysis(TGA), and Mass spectrometry(MS). $Zn(BH_4)_2$ can be tested for hydrogen evolution without further purification. The reaction to yield hydrogen is irreversible, the other products being compounds of Zn, and borane. $Zn(BH_4)_2$ thermally decomposes to release borane and hydrogen gas between about 85 and $150^{\circ}C$.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.111-118
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• 2006

The LBS (Location Based Service) location information is the element which is important decides the application of form service, Recently the location accuracy with the method which applies the wireless Internet DGPS improved inside 1 meter Like this. application of the LBS which corresponds In the location accuracy which Improves accurate the Location Information output system development which is accurate stands is essential. In this study which it sees it used 1:5000 digital map MS visual 6.0 Active X controls of the country geography intelligence Personnel and it developed the location information output module of web browser base. The location information output system which is developed it will be able to secure the convenient characteristic of precision and visual program of the digital map simultaneously and the maximum anger of LBS application is expected.

• Journal of Powder Materials
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• v.6 no.3
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• pp.238-245
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• 1999

The preparation of $n-TiO_2$ powder by the Chemical Vapor Synthesis process (CVS) was studied using the liquid metal organic precursor (TTIP). The residence time and the collection methods were considered as main processing variables through the experiments. The CVS equipment consisted of a micropump and a flashvaporizer, a tube furnace and a tubular collection device. The synthesis was performed at $1000^{\circ}C$ with various sets of collection zone. The residence time and the total system pressure were controlled in the range of 3~20 ms and 10 mbar, respectively. Nitrogen adsorption, X-ray diffraction and electron microscopy were used to determine particle size, specific surface area and crystallographic structure. The grain size of the as-prepared $n-TiO_2$ powder was in the range of 2~8 nm for all synthesis parameters and the powder exhibited only little agglomeration. The relationship between particle characteristics and the processing variables is reviewed based on simple growth model.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.180-183
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• 2007

본 논문은 데이터 서비스를 제공하는 CDMA2000 1X 시스템에서 보충 채널(Supplemental Channel)을 관리하는 효율적인 방법을 제안한다. 시스템 표준에 따르면 이동 단말(MS)은 기지국(BS)으로부터 보충채널 할당 메시지를 수신하여 그 내용에 따라 보충 채널을 할당/해제하도록 되어있다. 그러나 이동 단말이 기지국이 보낸 보충 채널 할당 메시지를 수신하지 못한 경우 보충 채널 데이터에 대한 비효율적인 재전송이 발생하게 된다. 본 논문에서 제안하는 유지 기간 연장 방법을 사용하면 조건에 맞을 경우 보충채널 할당 메시지를 수신하지 못한 이동 단말도 보충 채널을 통해 데이터를 계속 수신할 수 있다.