• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.29-33
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• 2017

Formation of Au particles in nonstoichiometric $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxide from aniline + hydrochloric acid mixtures and chloroauric acid in the ratios 30 : 1; 60 : 1; 90 : 1 (S1-S3) by volume and 0.01 mol of copper acetate, $Cu(OCOCH_3)_2.H_2O$, in each case is performed by sol-gel growth. Powder x-ray diffraction (XRD) results show Au particles are dispersed in tetragonal nonstoichiometric dicopper (I) dicopper (II) oxides, $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$). Average crystallite sizes of Au particles determined using Scherrer equation are found to be in the approximate ranges ${\sim}85-140{\AA}$, ${\sim}85-150{\AA}$ and ${\sim}80-150{\AA}$ in S1-S3, respectively which indicate the formation of Au nano-micro size particles in $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Hysteresis behaviour at 300 K having low loop areas and magnetic susceptibility values ${\sim}5.835{\times}10^{-6}-9.889{\times}10^{-6}emu/gG$ in S1-S3 show weakly ferromagnetic nature of the samples. Broad and isotropic electron paramagnetic resonance (EPR) lineshapes of S1-S4 at 300, 77 and 8 K having $g_{iso}$-values ${\sim}2.053{\pm}0.008-2.304{\pm}0.008$ show rapid spin-lattice relaxation process in magnetic $Cu^{2+}$ ($3d^9$) sites as well as delocalized electrons in Au ($6s^1$) nano-micro size particles in the $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Broad and weak UV-Vis diffuse reflectance optical absorption band ~725 nm is assigned to $^2B_{1g}{\rightarrow}^2A_{1g}$ transitions, and the weak band ~470 nm is due to $^2B_{1g}{\rightarrow}^2E_g$ transitions from the ground state $^2B_{1g}$(${\mid}d_{x^2-y^2}$>) of $Cu^{2+}$ ($3d^9$) ions in octahedral coordination having tetragonal distortion.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.88-95
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• 2007

Purpose: The purpose of this study was to compare the proapoptotic effects of matrix metal-loproteinase inhibitor (MMPI) and doxorubicin on wild-type p53 osteosarcoma cell line, socalled U2OS cell line. Materials and Methods: U2OS cells were treated with MMP inhibitor III (MMPI III) and doxorubicin, either respectively or simultaneously. In cells treated with doxorubicin, Fas-neutralizing antibody so called ZB4 was additionally treated to examine whether the doxorubicin played a role through the Fas/FasL pathway. Cells were analysed regarding to apoptosis and cell death by flow cytometry. Results: U2OS cells incubated with doxorubicin showed significant amount of cell death in dose-dependent manner. However, those incubated with MMPI III mostly remained viable state. In addition, there is no relationship between two drugs. Cells treated with doxorubicin and ZB4 at the same time did not show down regulation of apoptosis through inhibition of Fas/FasL pathway. Conclusion: It is important to re-examine MMP inhibitor's effect on other osteosarcoma cell line with wild-type p14 as well as wild-type p53 to evaluate its proapoptotic effect.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.49-65
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• 2011

Objectives: This study was performed to investigate the effects of Gagamsosokmyeong-tang(Jiajianxiaoxuming-tang) on the monosodium iodoacetate(MIA) induced early state osteoarthritis in rats. Methods: Osteoarthritis was induced by injection of MIA(0.25 mg) into knee joints of rats. Osteoarthritis rats were divided into control(n=8) and treated=8 group respectively, Control group was taken distilled water and treated group was taken extracts of Gagamsosokmyeong-tang(Jiajianxiaoxuming-tang) by orally for 20 days. Body weight was measured at 0, 5, 10, 15, 20 days after MIA injection. At the end of experiment, gross and histopathological examination on the articular cartilages of the knee joints were performed. Proteoglycan(PG) content of articular cartilages were analysed by safranine O staining method. The content of tumor necrosis $factor-{\alpha}(TNF-{\alpha})$, $interleukin-1{\beta}(IL-1{\beta})$ in synovial fluids were analysed by enzyme-inked inmunosorbent assay(ELISA) method. And also cycloxygenase-2(COX-2), matrix metalloproteinase 3(MMP-3), inducible nitric oxide synthase(iNOS), calpain immunochistochemical examination on the knee joints were performed. Results: PG content in articular cartilages of the treated group was significantly increased compared with control group. Histopathological osteoarthritic score of the treated group was significantly decreased compared with control group. $TNF-{\alpha}$ content in synovial fluids, expression of iNOS and calpain in synovial membrane of the treated group were significantly decreased compared with control group. But body weight, $1L-1{\beta}$ content in synovial fluids, expression of iNOS and MMP-3 of the treated group were not significantly changed compared with control group. Conclusions: On the basis of these results, we conclude that Gagamsosokmyeong-tang(Jiajianxiaoxuming-tang) has anti-arthritic effects on the MIA induced early stage osteoarthritis in rats.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.429-447
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• 1996

Transforming growth factor $-{\beta}$ is one of the polypeptide growth factors that mediate the activity of mesenchymal cells and regulate wound healing process via cell proliferation, migration and extracellular matrix formation. The purposes of this study is to evaluate the effects of transforming growth factor $-{\beta}$ on the protein synthetic activity of human periodontal ligament cells and human gingival fibroblasts. The cells which were prepared were primary cultured gingival fibroblasts and periodontal ligament cells from humans, and the fourth or sixth subpassage were used in the experiments. Cells were seeded and at a confluent state, 0, 0.5, I, 2.5, 5, 10 ng/ml $TGF-{\beta}$ and $2{\mu]Ci/ml\;[^3H]$ proline were added to the cells and cultured for 24 hours. Then, 1 and 5 ng/ml concentrations were selected and added to confluent cells and cultured for 24 and 48 hours. They were labeled with $2{\mu}Ci/ml\;[^3H]$ proline for 24 hours and a collagen assay was done by the Peterkofsky and Diegelman method. The results were presented as the mean disintegration per minute (dpm) per well and S.D. of four determinations, The results were as follows. : The total protein, collagen and noncollagenous protein synthesis in periodontal ligament cells and gingival fibroblasts were increased dose- dependently by transforming growth factor-p to 2.5-5 ng/ml concentration and decreased at 10 ng/ml concentration. The percent of collagen was slightly changed according to the concentration of transforming growth factor-po The effect of transforming growth $factor-{\beta}$ was not specific for collagen synthesis since it increased the total, noncollagenous and collagenous protein, simultaneously. In the comparison of protein synthetic activity between the human periodontal ligament cells and human gingival fibroblasts, the human gingival fibroblasts had higher activities than the human periodontal ligament cells at all times and concentrations of $TGF-{\beta}$. In the comparison of protein synthetic activity between the 24 hour effect and the 48 hour effect of $TGF-{\beta}$, the 48 hour cultured cells' synthetic activity decreased more than the 24 hour cultured cells at human periodontal ligament cells and human gingival fibroblasts. In conclusion, $TGF-{\beta}$ has important roles in the stimulation of protein synthesis in human periodontal ligament cells and human gingival fibroblasts. Thus, it may be useful for clinical application in periodontal regenerative procedures.

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.1-8
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• 1983

Classification on the group of Salix pseudo-lasiogyne growing in Korea, was conducted using cluster analysis, factor analysis, and principal component analysis. Thirty-six characters(Table 2) of the 5 basis species were measured. The phenograms and ordination plot showing the relationships between the species were made by applying the cluster analysis and principal component analysis. Five important factors, such as leaf blade width, number of right serration, angle of leaf apex, number of flowers in an ament, and the ratio of petiole length to width, were inferred from the rotated factor matrix, and their state values were presented in polygonal diagram. Salix pseduo-lasiogyne and S. babylonica were similarly correlated and linked in one group, S. dependens and S. matsudana for tortuosa were secondarily linked in the other group. S. koreensis appeared as an aliemated species from each of the two groups.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.401-414
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• 2018

Planing hull type ships are often equipped with interceptor or trim tab to improve the excessive trim angle which leads to poor resistance and sea keeping performances. The purpose of this study is to design a controller to control the attitude of the ship by controllable stern interceptor and validate the effectiveness of the attitude control by the towing tank test. Embedded controller, servo motor and controllable stern interceptor system were equipped with planing hull type model ship. Prior to designing the control algorithm, a model test was performed to identify the system dynamic model of the planing hull type ship including the stern interceptor. The matrix components of model were optimized by Genetic Algorithm. Using the identified model, PID controller which is a classical controller and sliding mode controller which is a nonlinear robust controller were designed. Gain tuning of the controllers and running simulation was conducted before the towing tank test. Inserting the designed control algorithm into the embedded controller of the model ship, the effectiveness of the active control of the stern interceptor was validated by towing tank test. In still water test with small disturbance, the sliding mode controller showed better performance of canceling the disturbance and the steady-state control performance than the PID controller.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.164-171
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• 2006

Recently Digital multimedia broadcasting (DMB) has been available as a commercial service. The users sometimes have difficulty in finding their preferred multimedia contents and need to spend a lot of searching time finding them. They are even very likely to miss their preferred contents while searching for them. In order to solve the problem, we need a method for recommendation users preferred only minimum information. We propose an algorithm and a system for recommending users' preferred contents using preference transition probability from user's usage history. The system includes four agents: a client manager agent, a monitoring agent, a learning agent, and a recommendation agent. The client manager agent interacts and coordinates with the other modules, the monitoring agent gathers usage data for analyzing the user's preference of the contents, the learning agent cleans the gathered usage data and modeling with state transition matrix over time, and the recommendation agent recommends the user's preferred contents by analyzing the cleaned usage data. In the recommendation agent, we developed the recommendation algorithm using a user's preference transition probability for the contents. The prototype of the proposed system is designed and implemented on the WIPI(Wireless Internet Platform for Interoperability). The experimental results show that the recommendation algorithm using a user's preference transition probability can provide better performances than a conventional method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.6
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• pp.342-347
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• 2016

We investigated the effect of $Bi_{1/2}(Na_{0.82}K_{0.18})_{1/2}TiO_3$ (BNKT) modification on the ferroelectric and electric-field-induced strain (EFIS) properties of lead-free $0.97Bi_{1/2}(Na_{0.82}K_{0.18})_{1/2}TiO_3-0.03LaFeO_3$ (BNKTLF) ceramics as a function of BNKT content (x= 0, 0.1, 0.2, 0.3, 0.5, and 1). BNKT-modified BNKTLF powders were synthesized using a conventional solid-state reaction method. As the BNKT content x increased from 0 to 1 the normalized electric-field-induced strain ($S_{max}/E_{max}$) was observed to increase at relatively low fields, i.e., below the poling field. Moreover, BNKTLF-30BNKT showed about 460 pm/V as low as at 3 kV/mm, which is a considerably high value among the lead-free systems reported so far. Consequently, it was confirmed that ceramic-ceramic composite, a mixture of an ergodic relaxor matrix and embedded ferroelectric seeds, is a salient way to make lead-free piezoelectrics practical with enhanced EFIS at low field as well as less hysterical.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.2
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• pp.123-136
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• 1996

A three-dimensional Galerkin-FEM model which can handle the temporal and spatial variation of density is presented. The hydrostatic approximation is used and density effects are included by means of conservation equation of heat and the equation of state. The finite difference grids are used in the horizontal plane and a set of linear-shape functions is used for the vertical expansion. The similarity transform is introduced to solve resultant matrix equations. The proposed model was first applied to the density-driven circulation in an idealized basin in the presence of the heat exchange between the air and the sea. The advection terms in the momentum equation were ignored, while the convection terms were retained in the heat equation. Coefficients of the vertical eddy viscosity and diffusivity were fixed to be constant. Calculation in a non-rotating idealized basin shows that the difference in heat capacity with depth gives rise to the horizontal gradient of temperature. Consequently, there is a steady new in the upper layer in the direction of increasing depth with compensatory counter flow .in the lower layer. With Coriolis force, geostrophic flow was predominant due to the balance between the pressure gradient and the Coriolis force. As a test in region of irregular topography, the model is applied to the Yellow Sea. Although the resultant flow was very complex, the character of the flow Showed to be geostrophic on the whole.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.6
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• pp.890-901
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• 2008

This study explores an initial framework for online product categorization by examining the relationships among Internet motivations, buying tendencies, and online purchase intentions for product categories. A total of 217 usable questionnaires were obtained from respondents in a southwestern state in the United States. A path model using a correlation matrix with maximum likelihood was estimated using LISREL 8.53. Findings indicated that Internet motivations consisted of four factors: Diversion, Economic, Information, and Social motivations. In addition, online products were classified into three categories based on purchase intentions: Sensory, Cognitive, and Search products. Estimated path model showed that diversion and economic motivations affected impulse buying tendency, whereas economic, information and social motivations influenced planned buying tendency in the online context. Also, the buying tendencies were significantly related to online purchase intentions for the product categories. Purchase intentions for sensory products were more strongly affected by impulse buying tendency, whereas purchase intentions for cognitive and search products were more strongly affected by planned buying tendency. Theoretical and managerial implications were discussed for devising an appropriate e-market strategy for specific product categories.