• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.11-20
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• 2013

Space-borne Synthetic Aperture Radar(SAR) has been one of the most effective tools for monitoring quantitative oceanographic physical parameters. The Doppler information recorded in single-channel SAR raw data can be useful in estimating moving velocity of water mass in ocean. The Doppler shift is caused by the relative motion between SAR sensor and the water mass of ocean surface. Thus, the moving velocity can be extracted by measuring the Doppler anomaly between extracted Doppler centroid and predicted Doppler centroid. The predicted Doppler centroid, defined as the Doppler centroid assuming that the target is not moving, is calculated based on the geometric parameters of a satellite, such as the satellite's orbit, look angle, and attitude with regard to the rotating Earth. While the estimated Doppler shift, corresponding to the actual Doppler centroid in the situation of real SAR data acquisition, can be extracted directly from raw SAR signal data, which usually calculated by applying the Average Cross Correlation Coefficient(ACCC). The moving velocity was further refined to obtain ocean surface current by subtracting the phase velocity of Bragg-resonant capillary waves. These methods were applied to Envisat ASAR raw data acquired in the East Sea, and the extracted ocean surface currents were compared with the current measured by HF-radar.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.17-24
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• 2018

Purpose: This study aimed to assess complications and outcomes of a new approach, that is, combining short course radiotherapy (SRT), concurrent and consolidative chemotherapies, and delayed surgery. Materials and Methods: In this single arm phase II prospective clinical trial, patients with T3-4 or N+ M0 rectal adenocarcinoma were enrolled. Patients who received induction chemotherapy or previous pelvic radiotherapy were excluded. Study protocol consisted of three-dimensional conformal SRT (25 Gy in 5 fractions in 1 week) with concurrent and consolidation chemotherapies including capecitabine and oxaliplatin. Total mesorectal excision was done at least 8 weeks after the last fraction of radiotherapy. Primary outcome was complete pathologic response and secondary outcomes were treatment related complications. Results: Thirty-three patients completed the planned preoperative chemoradiation and 26 of them underwent surgery (24 low anterior resection and 2 abdominoperineal resection). Acute proctitis grades 2 and 3 were seen in 11 (33.3%) and 7 (21.2%) patients, respectively. There were no grades 3 and 4 subacute hematologic and non-hematologic (genitourinary and peripheral neuropathy) toxicities and perioperative morbidities such as anastomose leakage. Grade 2 or higher late toxicities were observed among 29.6% of the patients. Complete pathologic response was achieved in 8 (30.8%) patients who underwent surgery. The 3-year overall survival and local control rates were 65% and 94%, respectively. Conclusion: This study showed that SRT combined with concurrent and consolidation chemotherapies followed by delayed surgery is not only feasible and tolerable without significant toxicity but also, associated with promising complete pathologic response rates.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.110-116
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• 2006

The mechanical property and cutting performance of the cutting tools coated with nanoscale nyktukatered nitride film have been investigated. $Ti_{0.54}Al_{0.46}N-CrN$ and $Ti_{0.84}Al_{0.16}N-NlN$ systems, which showed super-lattice in nanoscale multilayered coating, were deposited on WC-Co insert by UBM sputtering, The superlattice coatings with different bilayer periods were manufactured by controlling deposition parameters. The superlattice formation and hardness of the nanoscale multilayered nitride film and the cutting performance of the insert coated with the film were examined. The hardness and cutting performance were dependent on the bilayer periods of the coatings. The flank wear of the inserts with superlattice coatings were decreased over $20\%$, compared to those of commonly used cutting tools coated with TiAIN single phase.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.195-207
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• 2015

Physical properties of strontianite ($SrCO_3$) synthesized under variable conditions such as different ionic strength, temperature, and aging time were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). All synthesized samples show a single phase of strontianite. Crystallinity of the synthesized strontianite increases with increasing temperature and ionic strength with $NaNO_3$. Crystal sizes of the samples increase dramatically, and their morphology changes from rod or dendritic to prismatic shape as ionic strength and temperature of the solution increase. In addition, crystal sizes increase, and their morphology changes from rod or prismatic crystals to spheroidal aggregates with increasing aging time. These results suggest that changes in conditions of the synthesis for strontianite play an important role in controlling the crystallinity and morphology of results provide crucial information on the prediction for the physical properties of strontianite under different conditions during the formation of strontianite crystals.

• Korean Journal of Materials Research
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• v.21 no.5
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• pp.250-254
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• 2011

We have synthesized bluish-green, highly-efficient $BaSi_2O_2N_2:Eu^{2+}$ and $(Ba,Sr)Si_2O_2N_2:Eu^{2+}$ phosphors through a conventional solid state reaction method using metal carbonate, $Si_3N_4$, and $Eu_2O_3$ as raw materials. The X-ray diffraction (XRD) pattern of these phosphors revealed that a $BaSi_2O_2N_2$ single phase was obtained. The excitation and emission spectra showed typical broadband excitation and emission resulting from the 5d to 4f transition of $Eu^{2+}$. These phosphors absorb blue light at around 450 nm and emit bluish-green luminescence, with a peak wavelength at around 495 nm. From the results of an experiment involving Eu concentration quenching, the relative PL intensity was reduced dramatically for Eu = 0.033. A small substitution of Sr in place of Ba increased the relative emission intensity of the phosphor. We prepared several white LEDs through a combination of $BaSi_2O_2N_2:Eu^{2+}$, YAG:$Ce^{3+}$, and silicone resin with a blue InGaN-based LED. In the case of only the YAG:$Ce^{3+}$-converted LED, the color rendering index was 73.4 and the efficiency was 127 lm/W. In contrast, in the YAG:$Ce^{3+}$ and $BaSi_2O_2N_2:Eu^{2+}$-converted LED, two distinct emission bands from InGaN (450 nm) and the two phosphors (475-750 nm) are observed, and combine to give a spectrum that appears white to the naked eye. The range of the color rendering index and the efficiency were 79.7-81.2 and 117-128 lm/W, respectively. The increased values of the color rendering index indicate that the two phosphor-converted LEDs have improved bluish-green emission compared to the YAG:Ce-converted LED. As such, the $BaSi_2O_2N_2:Eu^{2+}$ phosphor is applicable to white high-rendered LEDs for solid state lighting.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.4
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• pp.378-387
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• 1994

To improve the properties of $PbTiO_3$ thin films successfully grown by thermal diffusion of 3 component layers of $Ti0_2/Pb/TiO_2(900{\AA}/900{\AA}/900{\AA})$ in preceding research, 3, 5, 7, 9, and 11 multilayer structures $(TiO_2/Pb/.../Tio_2)$ with thinner component layer of $200~300 {\AA}$ thick were deposited on Si substrate by RF sputtering, which were followed by RTA to form $PbTiO_3$ thin films. As a result, $PbTiO_3$ single phase was formed above $500^{\circ}C$. When the thickness of component layer reduced and the number of component layers increased, suppression of Pb-silicate and voids formation resulted in relatively sharp interfaces and the film composition became more homogeneous. Relative dielectric constants in MIM structure were independent of the annealing condition, but they increased with increasing thickness of the $PbTiO_3$ thin films. The maximum breakdown field in MIS structure reached 150kV/cm.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.1-18
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• 1996

There are many advantages when using IIF and DNA probe methods over anaerobic culture method in that they are time-and effort-saving, more precise and more sensitive. Furthermore, in IIF and DNA probe methods, the detection is possible only with small amount of bacteria, the quantitative analysis is possible, and the cell viability is not necessary. The purpose of this study is to observe the incidence of P.endodontalis by carrying out anaerobic culture, IIF and colony lift using DNA probe method respectively, and to compare these 3 methods in terms of effectiveness and sensitivity in order to identify the most effective detection method. 30 teeth with at least one clinical symptoms, with single canal, and with pulp necrosis were sampled. For sampling bacteria, access cavity was prepared after disinfecting tooth and its surroundings. Then the paper point was inserted up to the periapical area, leave there for a while, and finally it was placed into PRAS Ringer's sol. and PBS sol. In anaerobic culture method, P.endodontalis was identified by biochemical tests after subculturing black and brown colonies which were produced after 7 days of incubation on BAP and Brucella BAP in anaerobic chamber. To identify P.endodontalis in IIF method, species-specific polyclonal rabbit-antisera of P.endodontalis(ATCC 35406) was reacted with sampled PBS sol. dispensed onto glass slide, and then P.endodontalis was examined by phase contrast microscopy after incubating with Goat anti-rabbit lgG conjugated to Fluorescein isothiocyanate. For colony lift using DNA probe method, membranes were laid over colonies on the surface of BAP and were hybridized with cloned DNA probe of P.endodontalis. The existence of P.endodontalis was then identified by the methods of chemiluminescent detection and color metric detection. Black colony was found in 11 teeth out of 30 teeth and P.endodontalis was detected in 6 teeth (20 %) by anaerobic culture method, 16 teeth (53 %) by IIF method, and 7 teeth (23 %) by DNA probe method. IIF method is significantly better in detecting P.endodontalis than DNA probe method and anaerobic culture method. There was no significant differences between DNA probe method and anaerobic culture method. There was significant correlation between the formation of black colony and the existence of P.endodontalis. The probability of detecting P.endodontalis when black colony being present is 2.89 times higher than when not being present. There was significant relationship between the foul odor of clinical symptoms and P.endodontalis. The sensitivity of existing P.endodontalis when foul odor being present was 93.75 %, while the specificity of not existing P.endodontalis when foul odor not being present was 28.57 %. These results suggested that the probes of P.endodontalis will be used to decide the method and prognosis in endodontic treatments.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.255-262
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• 2011

Method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of pregabalin in plasma samples. Acquisition was performed by monitoring the transitions: m/z 160.1${\rightarrow}$142.2 for pregabalin and m/z 423.2${\rightarrow}$207.1 for losartan (as an internal standard). After cold acetonitrileinduced protein precipitation of the plasma samples, separation was performed with C18 column by isocratic mobile phase consisted of 10 mM ammonium acetate and acetonitrile (15:85, v/v). Results were linear over the concentration ranged from 0.1 to $10{\mu}g$/mL and the correlation coefficients (r) were $\geq0.99$. Intra- and inter-day precisions were $\leq6.02$ and $\leq11.04%$, respectively, and intra- and inter-day accuracies were 96.60-101.09 and 98.10-102.60%, respectively. This validated method was successfully applied to a bioequivalence study of two formulations of pregabalin, Daewoong pregabalin capsule (Daewoong Pharm. Co., Ltd.) and Lyrica$^{(R)}$ capsule (Pfizer Korea Ltd.) in twenty eight healthy Korean volunteers. The subjects received a single oral dose of each formulation (150 mg as pregabalin) in a randomized $2{\times}2$ crossover study and plasma samples were obtained from each subject at predetermined time intervals. Then, the pharmacokinetic parameters ($AUC_{0-t}$, $C_{max}$ and $T_{max}$) were calculated and statistically analyzed to assess the differences between two formulations. The 90% confidence intervals for the log-transformed data were acceptable range of log 0.8-log 1.25 (e.g., log 1.0048-log 1.0692 for AUC0-t, log 0.9142-log 1.0421 for $C_{max}$). Thus, $AUC_{0-t}$ and $C_{max}$ met the criteria of the Korea Food and Drug Administration (KFDA) for bioequivalence test indicating that Daewoong pregabalin capsule was bioequivalent to Lyrica$^{(R)}$ capsule.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.217-224
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• 2005

When L. monocytogenes ($10^{5}CFU/mL$) at exponential phase cells were heated for 5 min at $65^{\circ}C$ in the presence of the bacteriocin (30 BU/mL) produced by E. faecium MJ-14, the number of viable cells was markedly reduced at p < 0.05. The bactericidal effect of bacteriocin showed synergism with combination ot organic acids (citric acid or acetic acid) or chemical preservatives (sodium benzoate, sodium lactate, sodium nitrate or potassium nitrate). For example, the number of viable cells was reduced by 4.8 log units under combination of the bacteriocin (30 BU/mL) and sodium nitrate ($100{\mu}g/mL$), while it was reduced by 1.1 log unit only under single treatment of the bacteriocin after 12 k at $37^{\circ}C$. The addition of the bacteriocin (300 BU/mL) into skim milk inoculated with L. monocytogenes ($10^{5}$CFU/mL) reduced the cells by 1.5 log unit, in case of the cell suspension stored at $4^{\circ}C$ for 24 hr. Moreover, L. monocytogenes was reduced by 2 log unit when stored at $-20^{\circ}C$ for 7 days in gound pork added with 300 BU/mL of 린e bacteriocin.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1340-1350
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• 2009

The design and implementation of planar Active Phased Array Antenna System are described in this paper. This Antenna system operates at X-band with its bandwidth 10 % and dual polarization is realized using dual slot feeding microstrip patch antenna and SPDT(Single Pole Double Through) switch. Array Structure is $16\times16$ triangular lattice structure and each array is composed of TR(Transmit & Receive) module with more than 40 dBm power. Each TR module includes digital attenuator and phase shifter so that antenna beam can be electronically steered over a scan angle$({\pm}60^{\circ})$. Measurement of antenna pattern is conducted using a near field chamber and the results coincide with the expected beam pattern. From these results, it can be convinced that this antenna can be used with control of beam steering and beam shaping.