• Fire Science and Engineering
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• v.33 no.1
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• pp.23-29
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• 2019

Rechargeable battery such as lithium-ion battery has been noticed as a kinds of the energy storage system in the recent energy utilization and widely used actually in various small electronic equipment and electric vehicles. However, many thermal runaway caused battery accidents occurred recently, which still is obstacle for advanced application of lithium ion battery. One of the main differences to general fires is the existence of ionized electrolyte with electron during combustion. Therefore, we simply simulated the ion addition effects of battery fires by introducing an ionized fuel in jet diffusion flames. When the ionized methane through a corona discharge was used as fuel, the overall flame stability and shape such as flame length showed no significant difference from normal methane flame, but NOx and CO emissions measured at the post flame region decreased. The ion addition effect of methane oxidation was also numerically simulated with the modeling of hydrogen addition in the mixture. It was confirmed that the hydrogen addition at a fixed temperature had a similar effects on ionization of methane and hence could be modeled successfully.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.2
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• pp.1-10
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• 2019

Objectives : The objective of present study is to evaluate anti-inflammatory and anti-allergic effects of Perilla(Perilla frutescens; Labiatae, PF), the roots of Peucedanum praeruptorum(PP) and the root of Scutellaria baicalensis(SB) in vitro and anti-asthmatic effects of mixture of PF, PP and SB(PS) on ovalbumin (OVA)-induced asthma in BALB/c mice. Methods : Anti-inflammatory and anti-allergic effects were observed on the lipopolysaccharide(LPS) treated RAW 264.7 cells through Nitric Oxide(NO) production and RBL-2H3 cells through ${\beta}$-hexosaminidase. Anti-asthmatic effects were observed on the number of inflammatory cells in bronchoalveolar lavage fluid(BALF) and the level of IgE in serum on OVA-induced BALB/c mice. Results : The treatment of PF, PP and SB(12.5, 25, 50, $100{\mu}g/m{\ell}$) resulted in a significant inhibition of NO production in RAW 264.7 cells and mast cell degranulation in RBL-2H3 cells. Oral administration of PS(400mg/kg/day) resulted in a significant reduction in the numbers of eosinophils in BALF and level of IgE in serum. Conclusion : The oral administration of PS is effective in ameliorating the eosinophilic infiltration in vivo and thus can be a good therapeutic candidate for allergic asthma.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.6
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• pp.171-181
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• 2011

Proposed in this paper is the intelligent video surveillance system to effectively detect multiple loitering objects even that disappear from the out of camera's field of view and later return to a target zone. After the background and foreground are segmented using Gaussian mixture model and shadows are removed, the objects returning to the target zone is recognized using the chromaticity histogram and the duration of loitering is preserved. For more accurate measurement of the loitering behavior, the camera calibration is also applied to map the image plane to the real-world ground. Hence, the loitering behavior can be detected by considering the time duration of the object's existence in the real-world space. The experiment was performed using loitering video and all of the loitering behaviors are accurately detected.

• Journal of Korean Association for Spatial Structures
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• v.22 no.3
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• pp.25-32
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• 2022

In this paper, the instability of the domed spatial truss structure using wood and the characteristics of the buckling critical load were studied. Hexagonal space truss was adopted as the model to be analyzed, and two boundary conditions were considered. In the first case, the deformation of the inclined member is only considered, and in the second case, the deformation of the horizontal member is also considered. The materials of the model adopted in this paper are steel and timbers, and the considered timbers are spruce, pine, and larch. Here, the inelastic properties of the material are not considered. The instability of the target structure was observed through non-linear incremental analysis, and the buckling critical load was calculated through the singularities and eigenvalues of the tangential stiffness matrix at each incremental step. From the analysis results, in the example of the boundary condition considering only the inclined member, the critical buckling load was lower when using timber than when using steel, and the critical buckling load was determined according to the modulus of elasticity of timber. In the case of boundary conditions considering the effect of the horizontal member, using a mixture of steel and timber case had a lower buckling critical load than the steel case. But, the result showed that it was more effective in structural stability than only timber was used.

• 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.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.139-146
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• 2009

Objectives : This study was conducted to investigate the effect of HTE001, a multi-herbal mixture consisting of 10 herbs, Cornus Frutus, Schizandrae Fructus, Rubi Fructus, Cnidi Fructus, Acanthopanacis senticosi Radix, Cinnamomi Cortex, Eucommiae Cortex, Allii Bulbus, Rehmanniae Radix and Ginseng Radix, on electrostimulation-induced penile erection in rats. Methods : Intracavernous pressure (ICP) and mean arterial blood pressure (MAP) were simultaneously monitored through electric stimulation of the cavernous nerve after the oral administration of HTE001 (30, 100, 300 mg/kg) in normal rats. Statistical analysis was performed on maximal intracavernous pressure (ICP), maximal intracavernous pressure/mean arterial blood pressure (ICP/MAP) ratio, and the area under the curve (AUC) of ICP/MAP ratio. Results : Oral administration of HTE001 300 mg/kg caused the ICP to increase in a frequency-dependent manner. And HTE001 300 mg/kg treatment group showed the highest value in the ICP/MAP ratio and the AUC value of the ICP/MAP ratio compared to the control group at 2 Hz, 6 Hz and 10 Hz, respectively without an effect on the mean arterial blood pressure under the same stimulation of the cavernous nerve. Conclusions : These results show that HTE001 improve penile erection and prolong the decay period in normal rats without affecting mean arterial blood pressure, and suggest that HTE001 could be a good therapeutic candidate to treat erectile dysfunction.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.252-258
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• 2022

In this study, we propose a method for analyzing students' understanding of probability and statistics in small lectures at universities. A computer-based test for probability and statistics was performed on 95 science and engineering college students. After dividing the students' responses into 7 clusters using the Robust PCA and the Gaussian mixture model, the achievement of each subject was analyzed for each cluster. High-ranking clusters generally showed high achievement on most topics except for statistical estimation, and low-achieving clusters showed strengths and weaknesses on different topics. Compared to the widely used PCA-based dimension reduction followed by clustering analysis, the proposed method showed each group's characteristics more clearly. The characteristics of each cluster can be used to develop an individualized learning strategy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.445-451
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• 2006

This study was conducted to develop the interlayer mixture that absorbs the stress between the old concrete pavement and the asphalt overlay pavement layer. The elasticity, the flexibility, the consistency and the impermeability is required for high-elastic Stress Absorbing Interlayer(HSAI) to absorb and disperse the stress that causes the flexural and horizontal movements of the joint and the crack. The HSAI developed from foreign product was satisfied with the design criteria. The specimens using the HSAI showed the significant reduction of the reflective crack compared those not using the HSAI. The significance included that the life of shear failure and horizontal displacement resistance increased 4 times. The life of the share failure increased to 5 times and the horizontal displacement increased to 9 times according to the selection of surface course material which showed the excellence of the HSAI.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.6
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• pp.415-421
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• 2023

In this study, the piezoresistive properties of cementitious composites enhanced with carbon nanotubes for improved electrical conductivity were analyzed using a deep learning-based transformer algorithm. Experimental execution was performed in parallel for acquisition of training data. Previous studies on mixture design, specimen fabrication, chemical composition analysis, and piezoresistive performance testing are also reviewed in this paper. Notably, specimens in which fly ash substituted 50% of the binder material were fabricated and evaluated in this study, in addition to carbon nanotube-infused specimens, thereby exploring the potential enhancement of piezoresistive characteristics in conductive cementitious materials. The experimental results showed more stable piezoresistive responses in specimens with fly-ash substituted binder. The transformer model was trained using 80% of the gathered data, with the remaining 20% employed for validation. The analytical outcomes were generally consistent with empirical measurements, yielding an average absolute error and root mean square error between 0.069 to 0.074 and 0.124 to 0.132, respectively.

• Journal of Convergence Korean Medicine
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• v.6 no.1
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• pp.29-36
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• 2024

Objectives: Psoriasis is a common chronic inflammatory skin disease characterized by keratinocyte hyperproliferation and an excessive inflammatory response. Agents that can attenuate keratinocyte hyperproliferation and excessive inflammatory responses are considered potentially useful for the treatment of psoriasis. Daehwangmokdanpitang (DHMDPT) exhibits a broad range of bioactivities, including anti-proliferative and anti-inflammatory effects. This study aims to evaluate the anti-psoriatic potential of DHMDPT in vitro. Methods: HaCaT keratinocytes were stimulated with a mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish an in vitro psoriatic keratinocyte model. Cell viability was measured using the MTT assay. Quantitative real-time PCR (qRT-PCR) was performed to measure the mRNA levels of the hyperproliferative marker gene keratin 6 (KRT6) and inflammatory factors such as IL-6, TNF-α, and IL-23A. Additionally, chemokines including CCL5, CCL2, CCL20, and CXCL1 were measured by qRT-PCR. Results: DHMDPT attenuated M5-induced hyperproliferation, as indicated by a reduction in KRT6 expression in HaCaT keratinocytes. M5 stimulation significantly upregulated the mRNA levels of IL-6, TNF-α, and IL-23A. However, DHMDPT treatment attenuated the upregulation of IL-6 but not TNF-α or IL-23A. Additionally, DHMDPT inhibited the expression of CCL5, CCL2, and CXCL1, but not CCL20. Conclusion: DHMDPT effectively attenuated the M5-induced proliferation and inflammatory response in HaCaT keratinocytes. Therefore, DHMDPT could be an attractive candidate for future development as an anti-psoriatic agent.