• Korean Journal of Materials Research
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• v.9 no.1
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• pp.14-17
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• 1999

Tin oxide films as an anode layer for microbatteries were deposited by using rf magnetron sputtering. Characterization of the films was carried out in terms of working pressure in the range of 5~30 mtorr. Rf power and substrate temperature during deposition were fixed at 2.5W/$\textrm{cm}^2$ and A.T., respectively. The crystal orientation of $SnO_2$films was changed from (110) to (101) or (211) with the increasing working pressure. Refractive index and film density of the films also decreased with the increasing working pressure. The $SnO_2$ thin film formed under optimum conditions was found to have a reversible capacity of 446.9$\mu$Ah/$\textrm{cm}^2$-$\mu\textrm{m}$ and good reversibility when the working pressure was fixed at 10mtorr. As the working pressure decreased, film density increased. It was thought that the capacity of $SnO_2$films increased due to the increase in the amount of active materials which can react with Li electrochemically. Furthermore, cycle characteristics of the anode material was also influenced by film stress.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.139-145
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• 2006

Purpose: Although several chemotherapy regimens used against advanced gastric cancer (AGC) have been studied extensively in an attempt to further improve the prognosis of patients, to date, no standard chemo-therapeutic regimens have been established. The aim of this study was to determine the anti-tumor efficacy and safety of TS-1 or TS-1 plus cisplatin (CDDP). Material and Methods: We treated 78 patients with AGC either with $80\;mg/m^{2}$ of TS-1 for 28 days, which was followed by a 2-week rest, or with $80\;mg/m^{2}$ of TS-1 for 21 days and $80\;mg/m^{2}$ of CDDP on day 8 every 5 weeks. Results: Tumor response rates in the neoadjuvant chemotherapy group and in the recurrent or post-palliative surgery group were 87.5% and 32.4%, respectively, and they were 28.6% and 48.4%, respectively, in the TS-1 group and the TS-1 plus CDDP group. The survival rates in the recurrent and the post-palliative surgery group were significantly different according to the degree of tumor response (P=0.0016), but the one-year survival rates according to the kinds of regimens (TS-1 or TS-1/CDDP group) were not significantly different. The incidences of grade 3 or 4 adverse effects in the TS-1 and the TS-1/CDDP groups were 14.3% and 36.8%, respectively. Conclusion: The anti-tumor efficacy and safety of TS-1 and TS-1 plus CDDP in Korean patients with AGC seemed to be high with modest adverse effects, thus suggesting the possible use of this regimen as a standard chemotherapy for gastric cancer.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.777-784
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• 2015

This study verified the correlations between vegetation factors, such as the number of individual species and species diversity, and soil factors in Chamaecyparis obtusa (CO) stands in Jeollanam-do. Also, the site environmental factors that affect the annual growth of CO ring width were analyzed. Positive correlations were found between the species diversity index and Cation Exchange Capacity (CEC), available phosphate, and exchangeable $K^+$ (P<0.01). In addition, strong positive correlations were also found between the number of species that appeared in the study site and CEC, available phosphorus, exchangeable $K^+$ and exchangeable $Mg^{2+}$ (P<0.01). Tree ring growth showed strong correlations with the nutrient holding capacity and fertility of soil, including available phosphate, exchangeable $K^+$, CEC, and electrical conductivity (P<0.01). The explanatory variables of tree ring growth in CO were composed of exchangeable $K^+$, organic matter content, and soil pH. The regression model had a high level of explanatory power, 74.4%. In this model, the annual growth of CO ring width increased when exchangeable $K^+$ and organic matter content were higher but decreased when soil pH was lower. According to the analysis, it is found that the annual growth of CO ring width was significantly affected by soil fertility, including available phosphate, exchangeable $K^+$, CEC, and electrical conductivity. In addition, the soil fertility of CO stands seems to be significantly affected by the supply of fallen leaves from the understory vegetation of CO.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.115-122
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• 2022

As the impermeable area of soil increases due to urbanization, the water circulation system of the city is deteriorating. The existing guidelines for low impact development (LID) facilities installed to solve these water problems or in previous studies, engineering aspects are more prominent than landscaping aspects. This study attempted to present an engineering and landscaping model for reducing pollutants by identifying the effects of vegetation on rainfall outflows and pollutant reduction in bioretention and the economic aspects of planting. Based on the results of artificial rainfall monitoring at Jeonju Seogok Park and the literature on vegetation rainfall runoff and pollutant reduction performance, the best vegetation for reducing pollution compared to cost was Lythrum salicaria L and Salix gracilistyla Miq. was the best vegetation for carbon storage. If you insist to design plants with only these two plantation, there is no choice but to take risks such as biodiversity. Herbaceous plants such as Lythrum salicaria L can be replaced by death of the plants or pests if considered planting various plants. The initial planting cost could expensive, but it is also necessary to mix and plant Salix gracilistyla Miq, which are woody plants that are advantageous in terms of maintenance, according to the surrounding environment and conditions. Based on the conclusions drawn in this study, it can be a reference material when considering the reduction of pollution by species and carbon storage of vegetation in LID facilities.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.416-424
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• 2023

Concrete emits a large amount of carbon dioxide throughout its life cycle, and due to the societal demand for carbon dioxide reduction, research on storing carbon dioxide in concrete in the form of minerals is ongoing. In this study, cyanobacteria, which absorb carbon dioxide through photosynthesis and fix it as calcium carbonate, were applied to a porous concrete substrate, and the changes in the properties of the concrete substrate due to their special environmental curing condition were analyzed. The results showed that the calcium carbonate precipitation by the microorganisms was concentrated in the light-exposed surface area, and most of the precipitation occurred in the cement paste part, not in the aggregate. This microbially induced calcium carbonate precipitation enhanced the mechanical performance of the paste and improved the overall compressive strength as the curing age progressed. In addition, the increase in microbial biofilm and calcium carbonate improved the pore structure, which influenced the reduction in water permeability.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.178-182
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• 2007

Non-aqueous supercapacitors by using activated C and $LiMn_2O_4$ as an active material in a positive electrode were prepared and characterized. From the cyclic voltammetry and AC impedance analysis, the capacitive effect by electric double layer of activated carbon and the faradic effect by intercalation/deintercalation of $Li^+$ ion were observed. Increasing the ratio of $LiMn_2O_4$, specific capacitances and energy densities of supercapacitor were increased. At the ratio of 0.86:0.14 ($LiMn_2O_4:C$), the maximum specific capacitance of 17.51 Wh/L and energy density of 23.83 F/cc were obtained, which were more than twice of those for a conventional electric double layer capacitor. Even after 1,000 charge/discharge cycle, the supercapacitor by using the electrode containing 14% of activated carbon and 86% of $LiMn_2O_4$ showed 60% better specific capacitance and energy density than that by using the electrode containing 100% activated carbon.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3176-3183
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• 2010

A multi-scale fatigue life prediction methodology of composite pressure vessels subjected to multi-axial loading has been proposed in this paper. The multi-scale approach starts from the constituents, fiber, matrix and interface, leading to predict behavior of ply, laminates and eventually the composite structures. The multi-scale fatigue life prediction methodology is composed of two steps: macro stress analysis and micro mechanics of failure based on fatigue analysis. In the macro stress analysis, multi-axial fatigue loading acting at laminate is determined from finite element analysis of composite pressure vessel, and ply stresses are computed using a classical laminate theory. The micro stresses are calculated in each constituent from ply stresses using a micromechanical model. Three methods are employed in predicting fatigue life of each constituent, i.e. a maximum stress method for fiber, an equivalent stress method for multi-axially loaded matrix, and a critical plane method for the interface. A modified Goodman diagram is used to take into account the generic mean stresses. Damages from each loading cycle are accumulated using Miner's rule. Monte Carlo simulation has been performed to predict the overall fatigue life of a composite pressure vessel considering statistical distribution of material properties of each constituent, fiber volume fraction and manufacturing winding angle.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.100-109
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• 2016

Low impact development (LID) facilities are established for the purpose of restoring the natural hydrologic cycle as well as the removal of pollutants from stormwater runoff. Improved efficiency of LID facilities can be obtained through the optimized interaction of their major components (i.e., plant, soil, filter media, microorganisms, etc.). Therefore, this study was performed to evaluate the performances of LID facilities in terms of runoff and pollutant reduction and also to provide an optimal maintenance method. The monitoring was conducted on four LID technologies (e.g., bioretention, small wetlands, rain garden and tree box filter). The optimal SA/CA (facility surface area / catchment area) ratio for runoff reduction greater than 40% is determined to be 1 - 5%. Since runoff reduction affects the pollutant removal efficiency in LID facilities, SA/CA ratio is derived as an important factor in designing LID facilities. The LID facilities that are found to be effective in reducing stormwater runoff are in the following order: rain garden > tree box filter > bioretention> small wetland. Meanwhile, in terms of removal of particulate matter (TSS), the effectiveness of the facilities are in the following order: rain garden > tree box filter > small wetland > bioretention; rain gardens > tree box filter > bioretention > small wetland were determined for the removal of organic matter (COD, TOC), nutrients (TN, TP) and heavy metals (Cu, Pb, Cd, Zn). These results can be used as an important material for the design of LID facilities in runoff volume and pollutant reduction.

• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.427-434
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• 2003

In this paper, we present a speech-based Environmental Control System(ECS) and its application. In the concrete, an ECS using the speech recognition and an portable wheelchair lift control system with the speech synthesis are developed through the simulation and the embodiment. The developed system apply to quadriplegic man and we evaluate the result of physical effect and of mental effect. Speech recognition system is constructed by real time modules using HMM model. For the clinical application of the device, we investigate the result applied to 54-years old quadriplegic man during a week through the questionnaires of Beck Depression Inventory and of Activity Pattern Indicator. Also the motor drive control system of potable wheelchair lift is implemented and the mechanical durability is tested by structural analysis. Speech recognition rate results in over 95% through the experiment. The result of the questionnaires shows higher satisfaction and lower nursing loads. In addition, the depression tendency of the subject were decreased. The potable wheelchair lift shows good fatigue life-cycle as the material supporting the upper wheelchair and shows the centroid mobility of safety. In this paper we present an example of ECS which consists of real-time speech recognition system and potable wheelchair lift. Also the experiments shows needs of the ECS for korean environments. This study will be the base of a commercial use.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.4
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• pp.323-335
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• 2002

Object: The present study was accomplished to obtain a gene expression profile of the luminal epithelium during embryo apposition in comparison of implantation (1M) and interimplantation (INTER) sites. Material and Method: The mouse uterine luminal epithelium from IM and INTER sites were sampled on day 4.5 (Day of vaginal plug = day 0.5) by Laser Captured Microdissection (LCM). RNA was extracted from LCM captured epithelium, amplified, labeled and hybridized to microarrays. Results from microarray hybridization were analyzed by Significance Analysis of Microarrays (SAM) method. Differential expression of some genes was confirmed by LCM followed by RT-PCR. Results: Comparison of IM and INTER sites by SAM identified 73 genes most highly ranked at IM, while 13 genes at the INTER sites, within the estimated false discovery rate (FDR) of 0.163. Among 73 genes at IM, 20 were EST/unknown function, and the remain 53 were categorized to the structural, cell cycle, gene/protein expression, immune reaction, invasion, metabolism, oxidative stress, and signal transduction. Of the 24 structural genes, 14 were related especially to extracellular matrix and tissue remodeling. Meanwhile, among 13 genes up-regulated at INTER, 8 genes were EST/unknown function, and the rest 5 were related to metabolism, signal transduction, and gene/protein expression. Among these 58 (53+5) genes with known functions, 13 genes (22.4%) were related with $Ca^{2+}$ for their function. Conclusions: Results of the present study suggest that 1) active tissue remodeling is occurring at the IM sites during embryo apposition, 2) the INTER sites are relatively quiescent than IM sites, and 3) the $Ca^{2+}$ may be a crucial for apposition. Search for human homologue of those genes expressed in the mouse luminal epithelium during apposition will help to understand the implantation process and/or implantation failure in humans.