• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.4
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• pp.249-256
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• 2019

This paper presents an optimization framework of electrical impedance tomography for characterizing electrical conductivity profiles of concrete structures in two dimensions. The framework utilizes a partial-differential-equation(PDE)-constrained optimization approach that can obtain the spatial distribution of electrical conductivity using measured electrical potentials from several electrodes located on the boundary of the concrete domain. The forward problem is formulated based on a complete electrode model(CEM) for the electrical potential of a medium due to current input. The CEM consists of a Laplace equation for electrical potential and boundary conditions to represent the current inputs to the electrodes on the surface. To validate the forward solution, electrical potential calculated by the finite element method is compared with that obtained using TCAD software. The PDE-constrained optimization approach seeks the optimal values of electrical conductivity on the domain of investigation while minimizing the Lagrangian function. The Lagrangian consists of least-squares objective functional and regularization terms augmented by the weak imposition of the governing equation and boundary conditions via Lagrange multipliers. Enforcing the stationarity of the Lagrangian leads to the Karush-Kuhn-Tucker condition to obtain an optimal solution for electrical conductivity within the target medium. Numerical inversion results are reported showing the reconstruction of the electrical conductivity profile of a concrete specimen in two dimensions.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.370-378
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• 2019

The hepatic ischemic model has recently been widely used for the epidemiological study of ischemic reperfusion injury. This study was carried out to investigate the protective effect of vanillin, which is known to have antioxidant and anti-inflammatory effects, against hepatic and renal injury using an ischemia-reperfusion rat model, and we also investigated the mechanism related to vanillins' protective effect. The test material was administered at a concentration of 100 mg/kg for 3 days, followed by ligation of the liver for 60 minutes to induce ischemia reperfusion. As control groups, there was a negative control, sham control and ischemia-reperfusion-only ischemia reperfusion control, and the controls groups were compared with the drug administration group. In the vanillin group, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly inhibited compared with the AST and ALT activities of the ischemia-reperfusion group, and histopathological examination showed significant reduction of both inflammation and necrosis. The malondialdehyde (MDA) and superoxide dismutase (SOD) levels were significantly different from the ischemia-reperfusion group. In conclusion, vanillin showed a hepatocyte protective action by alleviating the cellular inflammation and cell necrosis caused by hepatic ischemia-reperfusion, and vanillin mitigated inflammatory changes in the kidney glomeruli and distal tubules. The protective effect is considered to be caused by vanillin's antioxidant function. Further studies such as on cell death and possibly vanillin's same effect on damaged tissue will be necessary for clinical applications such as organ transplantation.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.200-207
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• 2019

In this study, flexible supercapacitor based on the all solid state electrolyte with PVA (polyvinyl alcohol)-$H_3PO_4$, ionic liquid as a BMIMBF4 (1-buthyl-3-methylimidazolium tetrafluoroborate) and reduced graphene oxide/conductive polymer composite was fabricated and characterized electrochemical properties with function of its flexibility. In order to measure and compare that electrochemical performances (including cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge,after 0~100th bending test) of prepared flexible supercapacitor based on reduced graphene oxide/conducting polymer composite and all solid state electrolyte, we have conducted press machine with constant pressure ( 0.01/cm2) for $100^{th}$ bending test. As a result, specific capacitance of the flexible supercapacitor was 43.9 F/g which value decreased to 42.0 and 40.1 F/g after 50 and $100^{th}$ bending test, respectively. This result exhibited that decreased electrochemical property of the flexible supercapacitor effected on physical stress on the electrode after repeated bending test. In addition, we have measured that electrode surface morphology by SEM to prove its decreased electrochemical property of the flexible supercapacitor after prolonged bending test.

• Journal of Life Science
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• v.31 no.8
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• pp.736-744
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• 2021

Artemisia princeps Pampanini is an herbal medicine widely used to immune function-related diseases, such as anti-oxidative, anti-inflammatory, and antibacterial agents. In this study, we investigated the anti-inflammatory effects of AP extract and underlying mechanisms were evaluated in RAW 264.7 cells. The effects of AP extract were also studied in a complete Freund's adjuvant (CFA)-induced arthritis and lipopolysaccharide (LPS)-induced inflammation mouse model. In RAW 264.7 cells, AP extracts significantly inhibited the LPS-induced nitric oxide (NO) production and inducible NO synthase and cyclooxygenase-2 protein expression. The LPS-induced phosphorylation of mitogen-activated protein kinases and nuclear factor-κB was also significantly blocked by AP extract in RAW 264.7 cells. Oral administration of AP extract suppressed the increase in mouse paw edema and spleen index compared to CFA-treated mice group. Histologically, the infiltration of inflammatory cells was increased in cartilage and synovium in the CFA-treated mouse group, whereas it was suppressed in the AP extract-administered group. Furthermore, AP extract treatment significantly reduced the inflammatory cytokine, tumor necrosis factor-α, levels in CFA and LPS-treated mouse. In conclusion, the anti-inflammatory and anti-arthritis effect of AP extract was confirmed in both in vitro and in vivo models, suggesting that Artemisia princeps Pampanini may be a candidate material for arthritis treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.511-519
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• 2021

Slewing bearing is applied to the transmission of rotational power of the body and turret in a special vehicle for anti-aircraft weapons that overcomes the enemy flight system approaching at low altitudes with rapid response fire. When the turret load and impact load generated when shooting are combined in performing the combat mission of a special vehicle, structural stability must be secured to achieve a successful function. Among the components of the slewing bearing, the stability of the components against the complex loads acting by the turret drive and shooting was evaluated by considering the shape and material characteristics of the ring-gear, roller, and wire-race. As a research method for stability evaluation, based on engineering theory, the strength characteristics of the components were examined by numerical calculations. Finite element analysis was performed on components using the ANSYS analysis program. The results of theoretical analysis and the results of finite element analysis were very similar. A structural stability evaluation for the slewing bearing, which was performed mainly on the analysis, confirmed that the design strength of the slewing bearing determined in the preliminary design in the early stage of localization development was sufficient.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.562-574
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• 2021

Objective : This study is to evaluate the efficacy and safety of demineralized bone matrix (DBM) gel versus DBM gel with recombinant human bone morphogenetic protein-2 (rhBMP-2) used in transforaminal lumbar interbody fusion (TLIF). Methods : This study was designed as a prospective, multi-center, double-blind method, randomized study. All randomized subjects underwent TLIF with DBM gel with rhBMP-2 group (40 patients) as an experimental group or DBM gel group (36 patients) as a control group. Post-operative observations were performed at 12, 24, and 48 weeks. The spinal fusion rate on computed tomography scans and X-rays films, Visual analog scale pain scores, Oswestry disability index and SF-36 quality of life (QOL) scores were used for the efficacy evaluation. The incidence rate of adverse device effects (ADEs) and serious adverse device effects (SADEs) were used for safety evaluation. Results : The spinal fusion rate at 12 weeks for the DBM gel with rhBMP-2 group was higher with 73.68% compared to 58.82% for the DBM gel group. The 24 and 48 weeks were 72.22% and 82.86% for the DBM gel with rhBMP-2 group and 78.79% and 78.13%, respectively, for the DBM gel group. However, there were no significant differences between two groups in the spinal fusion rate at 12, 24, and 48 weeks post-treatment (p=0.1817, p=0.5272, p=0.6247). There was no significant difference between the two groups in the incidence rate of ADEs (p=0.3836). For ADEs in the experimental group, 'Pyrexia' (5.00%) was the most common ADE, followed by 'Hypesthesia', 'Paresthesia', 'Transient peripheral paralysis', 'Spondylitis' and 'Insomnia' (2.50%, respectively). ADEs reported in control group included 'Pyrexia', 'Chest discomfort', 'Pain', 'Osteoarthritis', 'Nephropathy toxic', 'Neurogenic bladder', 'Liver function analyses' and 'Urticaria' (2.86%, respectively). There was no significant difference between the two groups in the incidence rate of SADEs (p=0.6594). For SADE in the experimental group, ''Pyrexia' and 'Spondylitis' were 2.50%. SADE reported in the control group included 'Chest discomfort', 'Osteoarthritis' and 'Neurogenic bladder'. All SADEs described above were resolved after medical treatment. Conclusion : This study demonstrated that the spinal fusion rates of DBM gel group and DBM gel with rhBMP-2 group were not significantly different. But, this study provides knowledge regarding the earlier postoperative effect of rhBMP-2 containing DBM gel and also supports the idea that the longer term follow-up results are essential to confirm the safety and effectiveness.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.610-616
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• 2011

A series of polyurethane acrylate/ZnO (PUA/ZnO) nanocomposite films with different ZnO contents were successfully prepared via a UV-curing system. The synthesis and physical properties including morphological structure, thermal properties, barrier properties and optical properties, and antimicrobial properties were investigated as a function of ZnO concentration. FTIR and SEM results showed that these PUA/ZnO nanocomposite films did not have a strong interaction between PUA and ZnO, which may lead to no increase in thermal stability. By incorporating ZnO nanoparticles, the UV blocking and antibacterial properties increased as the content of ZnO increased. Specially, the oxygen permeability in composite films changed from $2005cc/m^2/day$ to $150cc/m^2/day$ by adding the ZnO nanoparticle, which indicates that the PUA/ZnO nanocomposite films can be applied as good barrier packaging materials. Physical properties of the UV-cured PUA/ZnO nanocomposite film are strongly dependent upon the dispersion state of ZnO nanoparticles and their morphology in the films.

• (The) Research of the performance art and culture
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• no.25
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• pp.31-56
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• 2012

This paper were reviewed on some problems in the early history of Chinese dance written by scholars of contemporary China. Results of the review, were found the following problems; First, In describe to the early history of Chinese dance, contemporary Chinese scholars do not distinguish myths, legends and historical materials, so the history of ancient Chinese dance makes to mystery, thus, eventually will cause a lack of truthfulness. Second, In order to fill the lack in the early history of Chinese dance, the Chinese scholar often use a drawing of earthenware or mural. However, in certain cases, the same drawing by the other observer to be interpreted differently. In this case, if use as evidentiary material, there is a problem. Third, Most contemporary Chinese scholars usually say that the origins of dance is labor. It is to have originated from materialistic historical view can be said. However, in ancient China, but rather about the origin and function of dance there were diverse views. Therefore, this aspect should be cautious.

• Journal of Communication Design
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• v.65
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• pp.530-538
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• 2018

Recently, museums are attracting the attention of visitors and society. However, research on museum interpretation conducted at domestic and foreign is relatively limited. The plan design of the museum commentary system was mainly based on the perspective of the experts, and most of them do not reflect the desire of the visitors. This study focused on visitors' experience of using museum Interpretation system. Through analyzing the effect of the Interpretation system of the museum that the visitor feels, we examined whether the Interpretation system of the museum meets the cultural needs of the visitors and identified the problems and deficiencies in the system. After that, the problems were rearranged and suggested the main elements of the commentary system of the museum finally, so as to help improve the museum commentary system and the educational function.In the first part of the study, the four major explanatory methods existing in the museum were confirmed. After that, we conducted in - depth interviews on four types of commentary methods and collected existing problems and deficiencies. The results of the type analysis were grouped into 14 types and the questionnaire was used to conduct a general survey on 14 problems. In this study, the user 's discomfort and problems were identified in the museum Interpretation system, and based on this, five key elements necessary for the museum Interpretation system were derived. Among them, inhalation is the weakest element in the museum commentary system, and future research will be conducted on how to apply each factor. I hope that you will be a reference material when you carry out research on the optimization of the Interpretation system of the museum and the improvement of the Interpretation experience.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.167-175
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• 2021

Far-infrared rays (FIR) are known to have various effects on atoms and molecular structures within cells owing to their radiation and vibration frequencies. The present study examined the effects of FIR on gene expression related to glucose transport through microarray analysis in rat skeletal muscle cells, as well as on mitochondrial biogenesis, at high and low glucose conditions. FIR were emitted from a bio-active material coated fabric (BMCF). L6 cells were treated with 30% BMCF for 24 h in medium containing 25 or 5.5 mM glucose, and changes in the expression of glucose transporter genes were determined. The expression of GLUT3 (Slc2a3) increased 2.0-fold (p < 0.05) under 5.5 mM glucose and 30% BMCF. In addition, mitochondrial oxygen consumption and membrane potential (ΔΨm) increased 1.5- and 3.4-fold (p < 0.05 and p < 0.001), respectively, but no significant change in expression of Pgc-1a, a regulator of mitochondrial biogenesis, was observed in 24 h. To analyze the relationship between GLUT3 expression and mitochondrial biogenesis under FIR, GLUT3 was down-modulated by siRNA for 72 h. As a result, the ΔΨm of the GLUT3 siRNA-treated cells increased 3.0-fold (p < 0.001), whereas that of the control group increased 4.6-fold (p < 0.001). Moreover, Pgc-1a expression increased upon 30% BMCF treatment for 72 h; an effect that was more pronounced in the presence of GLUT3. These results suggest that FIR may hold therapeutic potential for improving glucose metabolism and mitochondrial function in metabolic diseases associated with insufficient glucose supply, such as type 2 diabetes.