• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1867-1869
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• 1999

Pulse electric field induced electron emission from ferroelectrics has been studied with Pb$(Zr_xTi_{1-x})O_3$ ceramics with varying Zr/Ti ratio from 35/65 to 65/35, Electron emission was proved to be concentrated on the electrode edge by emission profile test and emission capture photographs. The 65/35 composition showed largest emission charge in lowest field and lowest emission threshold field. The emission characteristics are closely dependent on their ferroelectric properties in hysteresis curve. Electron emission charge increases with the polarization charge and emission threshold voltage is dependent on coercive field regardless of their composition. But dielectric constant has little relation with emission property. Electron emission charge increases exponentially with pulse electric field irrespective of composition. On the assumption that the surface potential is linear with the pulse electric field, electron emission can be regarded as a field emission at the electrode edge using Fowler-Nordheim plot of ln$(Q_e/E_{fe})$ to $1/E_{fe}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1073-1080
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• 2010

Realization of e-Navigation for maritime safety has become a hot research topic of these years. There has been lots of requirements of the convergence of VTS and new IT technology for prevent maritime accident caused huge mount of damage such as environmental damage of oil spill, human life and property. This paper aims to design of an intelligent VTS system based on context awareness and aids to navigation structure. The proposed system provides timely decision supporting mechanism using by situation awareness, reasoning, risk management technology and also provides information of aids to navigation for secure navigation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.117-120
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• 1996

In this paper, It is tested by spraying the spoiled liquids on the materials to prove the process of tracking under the various environments. Our experiments ware examined by setting the materials in the spray chamber, and by spraying the distilled water(DW), the city water(CW), the underground water(UW), the artificial acid rain(AR) and the salt water(SW) in applied voltage 3-6[KV]. As the result, the time of tracking breakdown became shorter in the order of DW < CW < UW < AR < SW. XLPE was eroded and its anti-bracking property was very strong, but that of PVC sheath was week. Especially it was confirmed that spraying by AR and SW on the PVC sheath had a serious effect on the lifetime of cable by the tracking breakdown.

• The Korea Journal of Herbology
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• v.27 no.5
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• pp.85-91
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• 2012

Objectives : In this study, we investigated the effect of Saposhnikoviae Radix on allergic responses in ovalbumin(OVA)-induced Allergic rhinitis(AR) mice. Methods : BALB/c mice were orally administrated with Saposhnikoviae Radix water extract (SRW, 50 mg/kg) or anti-histamine drug, Ketotifen (10 mg/kg) as a reference drug, followed by sensitization and challenge of OVA. Mice were measured clinical symptoms and the serum levels of histamine, IgE, IL-4, and IFN-${\gamma}$, and observed histopathological changes of nasal mucosa H&E staining. Results : SRW significantly decreased rubs and the serum levels of histamine, IgE, and IL-4, and then increased the serum levels of IFN-${\gamma}$ in OVA-induced AR mice, and inhibited histopathological changes of nasal mucosa with inflammation and the eosinophils infilteration. Conclusions : These data suggest that SRW has anti-allergic effect through the inhibitory property of Saposhnikoviae Radix against allergic responses in allergic rhinitis.

• Advances in Traditional Medicine
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• v.10 no.4
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• pp.304-309
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• 2010

Scutellaria pinnatifida A. Hamilt. (Lamiaceae) is an endemic Turkish herb. This plant is also endemic to Iran, and grows abundantly in other central and western Asian countries. Several species of the Scutellaria are known for their traditional uses in the treatment of hypertension, arteriosclerosis, inflammatory diseases, hepatitis, allergy, cancer and diarrhoea. Free-radical-scavenging property, antibacterial activity and brine shrimp toxicity of the n-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of S. pinnatifida were assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the resazurin microtitre plate based assay, and the brine shrimp lethality assay, respectively. The DCM and MeOH extracts exhibited free-radical-scavenging property, with the $RC_{50}$ values of 0.362 and 0.127 mg/ml, respectively. Among the solid-phase extraction fractions of the MeOH extract, the 50% aqueous-MeOH fraction showed the highest level of free-radicalscavenging activity ($RC_{50}$ = 0.039 mg/ml). While the DCM extract showed low level of antibacterial activity against Bacillus subtilis and ampicillin-resistant Escherichia coli, the MeOH extract was active against B. cereus, B. subtilis, E. coli and ampicillin-resistant E. coli. However, the minimum inhibitory concentrations (MIC) of the MeOH extract against these bacterial strains were >10 mg/ml. None of the extracts showed any significant toxicity towards brine shrimps ($LD_{50}$ = > 1.00 mg/ml).

• Korean Journal of Materials Research
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• v.27 no.6
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• pp.345-349
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• 2017

The effects of electron beam(EB) irradiation on the electrical and optical properties of InGaZnO(IGZO) thin films fabricated using a sol-gel process were investigated. As the EB dose increased, the electrical characteristic of the IGZO TFTs changed from semiconductor to conductor, and the threshold voltage values shifted to the negative direction. X-ray photoelectron spectroscopy analysis of the O 1s core level showed that the relative area of oxygen vacancies increased from 14.68 to 19.08 % as the EB dose increased from 0 to $1.5{\times}10^{16}electrons/cm^2$. In addition, spectroscopic ellipsometer analysis showed that the optical band gap varied from 3.39 to 3.46 eV with increasing EB dose. From the result of band alignment, it was confirmed that the Fermi level($E_F$) of the sample irradiated with $1.5{\times}10^{16}electrons/cm^2$ was located at the closest position to the conduction band minimum(CBM) due to the increase of electron carrier concentration.

• Journal of Integrative Natural Science
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• v.9 no.1
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• pp.72-79
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• 2016

Hexane, ethyl acetate and methanol extracts of whole plant of Boerhavia diffusa were screened for phytochemical and biological activities. Qualitative phytochemical screening via colorimetric method and the quantitative estimation of phenolic and flavonoid content were performed. Antioxidant assay using DPPH scavenging method was studied. Antimicrobial screening of plant extracts was done by cup diffusion technique. Cytotoxic activity of B. diffusa was studied by brine shrimp bioassay and anthelminthic activity was evaluated in vitro in Pheretima posthuma. This study revealed B. diffusa as a source of various phyto-constituents such as alkaloids, glycosides, saponins, tannins, carbohydrates, cardiac glycosides, flavonoids and terpenoids. Quantitative estimation of total phenol was found to be maximum in BEE i.e. $29.73{\pm}0.88$, BME $19.8{\pm}2.02$ and in BHE $9.15{\pm}0.304mgGAE/g$. Similarly, the total flavonoid content was found to be $17.44{\pm}0.75$ in BEE, $14.43{\pm}0.23$ in BHE and 3.678 mg QE/g in BME. Ethyl acetate extract showed its antibacterial activity against all tested pathogens except Escherichia coli whereas Staphylococcus aureus and Salmonella Typhi were resistant to methanol and hexane extract. The zone of inhibition (ZOI) of ethyl acetate extract against S. Typhi and B. cereus was found to be 18 mm and 14 mm respectively. The MIC value of BEE in S. Typhi was $3.125{\mu}g/ml$ and in B. cereus was $12.5{\mu}g/ml$. The preliminary screening of anticancer property of B. diffusa i.e. BSLT in methanol was found to be $165.19{\mu}g/ml$. B. diffusa was also found to contain anthelmintic property. The study helped in further exploration of medicinal properties of B. diffusa by phytochemical screening and biological activities paving the path for study and investigation in this plant.

• Journal of Information Processing Systems
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• v.12 no.1
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• pp.46-56
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• 2016

Dynamic textures are videos that exhibit a stationary property with respect to time (i.e., they have patterns that repeat themselves over a large number of frames). These patterns can easily be tracked by a linear dynamic system. In this paper, a model that identifies the underlying linear dynamic system using wavelet coefficients, rather than a raw sequence, is proposed. Content based threshold filtering based on Set Partitioning in a Hierarchical Tree (SPIHT) helps to get another representation of the same frames that only have low frequency components. The main idea of this paper is to apply SPIHT based threshold filtering on different bands of wavelet transform so as to have more significant information in fewer parameters for singular value decomposition (SVD). In this case, more flexibility is given for the component selection, as SVD is independently applied to the different bands of frames of a dynamic texture. To minimize the time complexity, the proposed model is implemented on a graphics processing unit (GPU). Test results show that the proposed dynamic system, along with a discrete wavelet and SPIHT, achieve a highly compact model with better visual quality, than the available LDS, Fourier descriptor model, and higher-order SVD (HOSVD).

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.43-49
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• 2018

Computer simulation was performed using the SIMION program to develop an electron gun for MCP cleaning. The target, MCP, is located 180mm from the source of the electron gun, and the diameter of the MCP is approximately 20mm. Therefore, we tried to find the condition that the beam diameter of electrons reaching the MCP is to be 20mm using four variables such as E, ${\phi}$, d1, d2, where the E is the energy of the electron reaching the MCP, the ${\phi}$ is the diameter of the extractor, and the d1 and the d2 are the distance from the electron source to the end of the extractor tube, and to the wall of chamber, respectively. As a result of simulation, we figuried out that the E and the d2 have little effect on the beam diameter. On the other hand, we also found that the beam diameters were very sensitive to the d1 and varied relatively large with respect to the ${\phi}$, and the d1 was the secondary order function of the ${\phi}$. Therefore we found that this function will allow us to design electron guns that are suitable for the purposes of this study.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.15-23
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• 2013

Objectives : To clarify the possible effects of Sinapis Semen and Raphani Semen on the development of pulmonary eosinophilic inflammation in a asthmatic mouse model. Methods : BALBav/c mice were sensitized to OVA followed intratracheally and by aerosol allergene challenges. We investigated the effect of Sinapis Semen and Raphani Semen on airway hyperresponsiveness, eosinophiic infitratio, immune cell phenotype, The2 cytokine product, and OVA-spedific IgE production. Results : Total lung cells, eosinophils, and lung leukocytes, OVA specific IgE levels, and Th 2cytokine levels such as IL-5, IL-13, IL-17, TNF-alpha, and eotaxin in BALF were reduced compared with those of OVA sensitized asthma mice (control). The absolute numbers of $CD3^+$, $CD3^+/CD69^+$, $CD3^-/CCR3^+$, $CD4^+$, $CD8^+$, $Gr-1^+/CD11b^+$, $B220^+/CD22^+$, $B220^+/IgE^+$ cells in lung tissiues significantly reduced compared to those of control. Specially total lung cells in BALF and the absolute number of $CD3^+/CD69^+$ and, $B220^+/IgE^+$ cells in lung tissiue effectively reduced in Sinapis Semen plus Raphani Semen compared to those of Sinapis Semen and Raphani Semen. Conclusions : These results indicate that Sinapis Semen plus Raphani Semen has deep inhibitory effects on airway inflammation and hyperresponsiveness in asmatic mouse model and also has effect of suppression of IL-5, IL-13, IL-17, OVA specific IgE production in BALF. The results verified that Sinapis Semen, Raphani Semen, and Sinapis Semen plus Raphani Semen could act as a immunomodulator which possess anti-inflammatory and anti-asthmatic property by modulating the relationship of Th1/Th2 cytokine imbalance.