• Journal of Sensor Science and Technology
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• v.23 no.6
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• pp.368-376
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• 2014

In order to measure the segmental impedance of the body, a bioelectrical impedance measurement system (BIMS) using multi-frequency applying method and two-electrode method was implemented in this study. The BIMS was composed of constant current source, automatic gain control, and multi-frequency generation units. Three experiments were performed using the BIMS and a commercial impedance analyzer (CIA). First, in order to evaluate the performance of the BIMS, four RC circuits connected with a resistor and capacitor in serial and/or parallel were composed. Bioelectrical impedance (BI) was measured by applying multi-frequencies -5, 10, 50, 100, 150, 200, 300, 400, and 500 KHz - to each circuit. BI values measured by the BIMS were in good agreement with those obtained by the CIA for four RC circuits. Second, after measuring BI at each frequency by applying multi-frequency to the left and right forearm and the popliteal region of the body, BI values measured by the BIMS were compared to those acquired by the CIA. Third, when the distance between electrodes was changed to 1, 3, 5, 7, 9, 11, 13, and 15 cm, BI by the BIMS was also compared to BI from the CIA. In addition, BI of extracellular fluid (ECF) was measured at each frequency ranging from 10 to 500 KHz. BI of intracellular fluid (ICF) was calculated by subtracting BI of ECF measured at 500 kHZ from BI measured at seven frequencies ranging from 50 to 500 KHz. BI of ICF and ECF decreased as the frequency increased. BI of ICF sharply decreased at frequencies above 300 KHz.

• Journal of Life Science
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• v.12 no.6
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• pp.803-811
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• 2002

The present study was carried out for research and development of natural antimicrobial from extract of Stachys sieboldii MIQ against food borne bacteria. The hexane extract of Stachys sieboldii MIQ at 250$\mu\textrm{g}$/$m\ell$ per disc showed 15 ~ 20 mm inhibition zone against gram positive and gram negative barteria. Minimum inhibitory concentration (MIC) of hexane extract was 250${\mu}g$/$m\ell$against Bacillus cereus, 250~500${\mu}g$/$m\ell$against Listeria monocytogenes, 500${\mu}g$/$m\ell$ against Staphylococcus aureus, Psedomonas aeruginosa. Observation by transmission electron microscope, showed that disruption of the cell wall assumed to be due to the bactericidal activity. In addition, the membrane integrity of the sensitive cells was disrupted by exposure to Stachys sieboldii MIQ extract on the D-$\beta$-galatosidase activity as substrate of O-nitrophenol-$\beta$-D-galacto-pyranoside. The hexane extract of Stachys sieboldii MIQ was very stable on the pH and thermal stability.

• Journal of Korea Water Resources Association
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• v.45 no.8
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• pp.805-814
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• 2012

Most hydrologic data are obtained by ground observations. New observation methods are needed for some regions to overcome difficulties in accessibility and durability of long-term observation. In 2002, NASA launched twin satellites named GRACE which were designed to measure the gravitational field of the earth. Using the GRACE monthly gravity level-2 data, we calculated terrestrial water storage change (TWSC) of the Korean peninsula in various spatial smoothing radii (0 km, 300 km, 500 km). For the validation of GRACE-based TWSC, we compared it with land-based TWSC which was obtained using the ground observation data: precipitation and evaporation from WAMIS, and runoff from GLDAS. According to the mean square-error test, GRACE-based TWSC best fits the land-based one at 500 km smoothing radius. The variation of the terrestrial water storage in the Korean peninsula turned out to be 0.986 cm/month, which means that appropriate measures should be prepared for sustainable water resources management.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.270-276
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• 1987

The fifty percent effective concentration (EC50) and the minimum inhibitory concentration (MIC) of iprodione on the resistant isolates of Alternaria mali obtained from infected leaves in Kyeongsan region ranged $550\~1,310{\mu}g/ml$ and $33,800-39,800{\mu}g/ml$, respectively. Conidia germination of the resistant isolates reached $70\%$ on PSA added with iprodione, $500{\mu}g/ml$ When treated with $500{\mu}g/ml$ iprodione soon after the inoculation the diameters of lesions on apple fruits 7days after inoculation with the resistant isolates were 1.6-14.6mm but no lesions appeared on those inoculated with the sensitive isolates. A similar trend of responses with the sensitive isolates was shown to benomyl, chlorothalonil, garbenda, thiophanatemethyl and triademefon with the resistant isolates. One isolate among the resistant ones was cross resistance to captan and folpet that were effective to the sensitive isolates.

• Journal of Life Science
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• v.11 no.6
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• pp.543-553
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• 2001

Lead poisoning is currently one of the major public health problems in industrialized countries. Several chelating agents have been developed and used to treat the lead poisoning. It was recently proposed that garlic, having a large quantity of S-S compounds, may react readily with lead, producing various sulfur componds, and thus provide curative and protective effects on the lead toxicity. The present study was undertaken to evaluate this possibility in experimental animals. The garlic treatment on rats pre-exposed to lead significantly enhanced urinary excretion of lead at a garlic dose of 500 mg/kg and decreased the bloon level of lead at both 250 and 500 mg/kg doses. The administration of grilic 500mg/kg along with lead significantly alleviated the renal histological alterations induced by lead. These results suggest that garilic has a curative as well as a protective effect against lead poisoning , thus it may act as a chelator of lead.

• The Journal of the Korea Contents Association
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• v.10 no.12
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• pp.84-90
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• 2010

In this paper, we propose a quadratic discriminant analysis based approach for improving the discriminating strength of weak classifiers based on simple Haar-like features that were used in the Viola-Jones object detection framework. Viola and Jones built a strong classifier using a boosted ensemble of weak classifiers. However, their single threshold (or decision boundary) based weak classifier is sub-optimal and too weak for efficient discrimination between object class and background. A quadratic discriminant analysis based approach is presented which leads to hyper-quadric boundary between the object class and background class, thus realizing multiple thresholds based weak classifiers. Experiments carried out for car detection using 1000 positive and 3000 negative images for training, and 500 positive and 500 negative images for testing show that our method yields higher classification performance with fewer classifiers than single threshold based weak classifiers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1442-1447
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• 2004

In this paper, a 6-Bit CMOS Folding and Interpolating AD Converter is presented. The converter is considered to be useful as an integrated part of a VLSI circuit handling both analog and digital signals as in the case of HDD or LAN applications. A built-in analog circuit for VLSI of a high-speed data communication requires a small chip area, low power consumption, and fast data processing. The proposed folding and interpolating AD Converter uses a very small number of comparators and interpolation resistors, which is achieved by cascading a couple of folders working in different principles. This reduced number of parts is a big advantage for a built-in AD converter design. The design is based on 0.25m double-poly 2 metal n-well CMOS process. In the simulation, with the applied 2.5V and a sampling frequency of 500MHz, the measurements are as follows: power consumption of 27mw, INL and DNL of $\pm$0.1LSB, $\pm$0.15LSB each, SNDR of 42dB with an input signal of 10MHz.

• Korean Journal of Optics and Photonics
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• v.11 no.5
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• pp.360-364
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• 2000

We demonstrate self-starting passIve mode locking of a Cr:LiSAF laser, using a SCIDlconduclor Saturable Absorber Mirror (SESAM), Two high-power red semiconductor lasers (Coherent S-67-500C-100-H) of wavelength 667 nm and maximum power of 500 mW were used as pump lasers, The cavity has 10 cm radius-ai-curvature folding minors, two SF 10 prisms, a 99% reflectivity output coupler and a SESAM at dIe focus of a 10 cm radIus-at-curvature mirror. We used the laser crystal in BrewsterBrewster shape with 1 5% $Cr^{+3}$ ion concentration and the length of 6 mm, An X-shaped resonator was used to compensate the astigmatism induced by tile crystal. The structure of the SESAM cOllSists of 30 pmr of $AlAs/Al_{0.15}Ga_{0.85}As$ layer, wi1l1 a 10 nm GaAs quantum well situated in the topmost layer Output spectra were centeled at 833 nm, with 4 nm spectral bandwidth and pulse width was measured to be 220 fs, Output power of 3 mW is obtained at a pump power of 800 mW. 00 mW.

• Journal of the Korea Society for Simulation
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• v.25 no.3
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• pp.125-132
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• 2016

This study intended to exploratively depict the influence of interaction between Environmental Uncertainty and Learning Orientation of Korean IT companies on Marketing Capability which was adopted as one of the organizational performance indicator. Statistical Results based on AMOS and SPSS showed that smaller-sized companies under 500 employees are more inclined to desperately and flexibly meet and adapt to their environmental uncertainty, resulting positive performance, that is, marketing capabilities. On the other hand, larger-sized companies over 500 employees showed no significant interaction effect. This result of the study induces the reasoning that the differences in competitive environment and market leadership accrued by organizational size may also incur differences in environmental adaptive mechanism. However, this reasoning can have some limitation in that the types and traits of IT firms are so different. Therefore, this topic suggests the necessity of follow-up researches using enlarged samples in IT industry and comparative studies in other industries.

• Korea Journal of Hospital Management
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• v.29 no.3
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• pp.54-69
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• 2024

Purposes: This study aims to analyze the location patterns, concentration, and accessibility of clinics in Seoul with the grids of a geographic information system(GIS) and provide useful indicators for research on hospital and clinic management and policies based on the results. The study especially sets out to identify areas falling behind in the service of the essential medical care departments based on an analysis with 250m×250m grids and contribute to efficient medical business management and public healthcare policies based on the results. Methodology: The study analyzed clinics in Seoul in terms of concentration, distribution and clustering patterns, accessibility, and hot spots by dividing the entire city into 500m×500m cells and generating grids. The accessibility analysis for the essential medical care departments was especially in detail based on grids in a 250m×250m cell size. Findings: The Herfindahl results show that plastic surgery and rehabilitation medicine recorded the highest concentration level. General medicine and dermatology recorded the highest Moran's I value, and internal medicine was the highest in hot spots. Obstetrics and gynecology capable of child delivery showed considerably lower accessibility in the grids corresponding to Gangseo-gu, Yangcheon-gu, and Gwanak-gu. Surgery had low accessibility in the grids corresponding to the northern parts of Gangseo-gu for the total population. Practical Implication: Unlike previous studies whose analyses covered wide areas, the present study examined minute spatial patterns, concentration, and accessibility based on an analysis with 500m×500m or 250m×250m grids. Based on its findings, the study expects a more minute analysis for future research on medical business management and policies.