• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.486-492
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• 2013

This study has been conducted to establish the optimal extraction process and HPLC analysis method for the determination of marker compounds as a part of the materials standardization for the development of health functional food materials from Astragali radix. Five extraction conditions including the shaking extraction at room temperature and the reflux extraction at $85^{\circ}C$ with 30%, 50% and 95% ethanol were evaluated. Reflux extraction with 50% ethanol showed the highest extraction yield as $27.27{\pm}2.27%$, while the extraction under reflux with 95% ethanol showed significantly the lowest yield of $10.55{\pm}0.24%$. The quantitative determination methods of calycosin-7-O-${\beta}$-D-glucoside and calycosin as marker compounds of Astragali radix extracts were optimized by HPLC analysis using a Thermo Hypersil column ($4.6{\times}250mm$, $5{\mu}m$) with the gradient elution of water and acetonitrile as the mobile phase at the flow rate of $0.8mLmin^{-1}$ and a detection wavelength of 230nm. The HPLC/UV method was applied successfully to the quantification of two marker compounds in Astragali radix extracts after validation of the method with the linearity, accuracy and precision. The contents of calycosin-7-O-${\beta}$-D-glucoside and calycosin in 50% ethanol extracts by reflux extraction were significantly higher as $1,700.3{\pm}30.4$ and $443.6{\pm}8.4{\mu}g-1$, respectively, comparing with those in other extracts. The results indicate that the reflux extraction with 50% ethanol at $85^{\circ}C$ is optimal for the extraction of Astragali radix, and the established HPLC method are very useful for the evaluation of marker compounds in Astragali radix extracts to develop the health functional material from Astragali radix.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.5
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• pp.513-527
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• 2000

This paper describes our experience to design and implementation of a collaborative system framework that allows to develop certain collaborative applications such as 3D animation, computer game, and industrial design. The collaborative system enables users, who located in geographically long distance, to do collaborative work in a single virtual space. The proposed system basically consists of client and server system. The goal of proposed system is to support scalability, portability, and platform independent. In order to achieve these, the server is implemented in Java platform and is adopted to the hybrid architecture which takes the advantages both in centralized and decentralized collaborative system. We construct the server base on its functional characteristics so called User Manager Server (UMS), Session Manager Server (SMS), and Information Server (IS), The UMS manages the users who are taking part in the collaborative operations. The SMS supports the conferencing in the proposed system. The IS provides the connection methods among the UMSs. For user's convenience, we implement the client using Visual C++ in Windows. We also expend the functions of 3D Studio Max to distributed environment by means of the plug-in module, and facilitate the chatting and white board functions as well.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.561-573
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• 2017

Nakdong River was recently dredged with multi-functional weirs construction. Therefore, the depth was deepened and the lag time also increased. As a result, stratification occurred in some sections with deep water depth, and it also caused the increase of algal bloom phenomenon. The purpose of this study is to evaluate reproducibility of stratification in the Nakdong River by applying the EFDC model, which is a three-dimensional hydraulic and water quality analysis model proving the reproducibility of stratification phenomena in reservoirs and estuaries. In order to reproduce the Nakdong river water temperature and DO stratification, EFDC model was constructed in the downstream part of the Nakdong river and sensitivity analysis was performed on key parameters sensitive to stratification. Sensitivity analysis was used to reproduce stratification by selecting optimal parameters. The results of this study can be used as basic data for the analysis of various destratification scenarios.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.317-327
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• 2008

Go-Yang city, rural region by the 1980s, had rapidly grown to the big city for only 15 years because of Il-San new town development which was developed during $1990{\sim}1995$. So the population and industrial function were greatly increased too. The change of urban spatial structure was grasped by tracing the distribution of population, household and industries of Go-Yang city during $1990{\sim}2005$. The new urban center had grown to the center of the whole city, while the industries of existing centers were extended to the neighbor areas. The existing centers had been changed into 3 types - (1) changed into a part of new urban center, (2) declined to sub-center with small merchant facilities. (3) continuously grown with the development of whole city. As a result, a new town development had changed the urban structure by creating new functional relationships among the existing and new centers rather the existing centers had declined.

• Design & Manufacturing
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• v.17 no.3
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• pp.15-20
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• 2023

In the fine blanking process, which is a press operation known for producing parts with narrow clearances and high precision through the application of high pressure, die roll often occurs during the shearing process when the punch penetrates the material. This die roll phenomenon can significantly reduce the functional surface of the parts, leading to decreased product performance, strength, and fatigue life. In this research, we conducted an in-depth analysis of the factors influencing die roll in the curvature area of the fine blanking process and identified its root causes. Subsequently, we designed and experimentally verified a die roll reduction process specifically tailored for the door latch manufacturing process. Our findings indicate that die roll tends to increase as the curvature radius decreases, primarily due to the heightened bending moment resulting from reduced shape width-length. Additionally, die roll is triggered by the absorption of initial punch energy by scrap material during the early shearing phase, resulting in lower speed compared to the product area. To mitigate the occurrence of die roll, we strategically selected the Shaving process and carefully determined the shaving direction and clearance area length. Our experiments demonstrated a promising trend of up to 75% reduction in die roll when applying the Shaving process in the opposite direction of pre-cutting, with the minimum die roll observed at a clearance area length of 0.2 mm. Furthermore, we successfully implemented this approach in the production of door latch products, confirming a significant reduction in die roll. This research contributes valuable insights and practical solutions for addressing die roll issues in fine blanking processes.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.197-208
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• 1997

Class III malocclusion patients can be approached with many different types of treatment methods, and thus, each patient's problems must be accurately evaluated to allow selection of the best possible treatment method. Cephalometric analysis is an essential part of diagnosis and treatment planning of orthodontic patients, and it would certainly be helpful if reliable cephalometric guidelines could be set. The author divided 482 Class III malocclusion patients(253 males and 229 females) into fourgroups according to different types of treatment methods they have received to correct imbalance between upper and lower jaws: 1) orthopedic appliance (face mask & RPE), 2) camouflage treatment with fixed appliance, 3) surgical-orthodontic treatment, 4) cross-bite correction with removable plates/ functional appliance. Cephalometric values at the time of first clinical examination were compare among the four groups. Cephalometric analysis indicates the following results: 1)the amounts of antero-posterior and vertical skeletal discrepancies and dental compensation were greatest in surgery group 2) SNB, Wits, distance from Nasion Perpendicular Plane to point a facial angle, facial convexity, and APDI were greater in orthopedic appliance group than fixed appliance(camouflage) group, but there was no statistical difference 3) removable plates/ functional appliance group showed least amounts of skeletal discrepancies and dental compensation with statistical significance.

• Environmental Mutagens and Carcinogens
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• v.26 no.3
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• pp.77-85
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• 2006

2,3,7,8-Tetrachlorodibenzo-$\rho$-dioxin(TCDD) displays high toxicity in animals and has been implicated in human carcinogenesis. Although TCDD is recognized as potent carcinogens, relatively little is known about their role in the tumor promotion and carcinogenesis. It is known that TCDD can increase of cancer risk from various types of tissue by a mechanism possibly involving the aryl hydrocarbon receptor (AhR) activation. In this study, effects of TCDD on cellular proliferation of normal human skin and lung fibroblasts, Detroit551 and WI38 cells were investigated. In addition, to enhance our understanding of TCDD-mediated carcinogenesis, we have investigated process in which expression of Erk1/2, cyclinD1, oncogene such as Ha-ras and c-myc, and their cognate signaling pathway. TCDD that are potent activators of AhR-mediated activity was found to induce significant increase of cytochrome P4501A1 mRNA expression, suggesting a presence of functional AhR. These results support that CYP1A1 enzyme may be involved in the generation of TCDD-induced toxicity. Moreover mitogen-activated protein kinases (MARKs) phosphorylation and cyclin D1 overexpression are induced by TCDD, which corresponded with the progression of cellular proliferation. However, TCDD did not affected Ha-ras and c-myc mRNA expression. Taken together, it seems that TCDD are could be a part of cellular proliferation in non-tumorigenic normal human cells such as Detroit551 and WI38 cells through the upregulation of MAPKs signaling pathway regulating growth of cell population. Therefore, AhR-activating TCDD could potentially contribute to tumor promotion and Detroit551 and WI38 cells have been used as a detection system of tumorigenic effects of TCDD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1610-1616
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• 2016

This study aimed to establish an optimal extraction process and high performance liquid chromatography-ultraviolet (HPLC-UV) analytical method for determination of 3,5-dicaffeoylquinic acid (3,5-DCQA) as a part of materials standardization for the development of a xanthine oxidase inhibitor as a health functional food. The quantitative determination method of 3,5-DCQA as a marker compound was optimized by HPLC analysis using a Luna RP-18 column, and the correlation coefficient for the calibration curve showed good linearity of more than 0.9999 using a gradient eluent of water (1% acetic acid) and methanol as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 320 nm. The HPLC-UV method was applied successfully to quantification of the marker compound (3,5-DCQA) in Aster glehni extracts after validation of the method with linearity, accuracy, and precision. Ethanolic extracts of A. glehni (AGEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 30, 50, 70, and 80% ethanol for 3, 4, 5, and 6 h, respectively. Among AGEs, 70% AGE at $70^{\circ}C$ showed the highest content of 3,5-DCQA of $52.59{\pm}3.45mg/100g$ A. glehni. Furthermore, AGEs were analyzed for their inhibitory activities on uric acid production by the xanthine/xanthine oxidase system. The 70% AGE at $70^{\circ}C$ showed the most potent inhibitory activity with $IC_{50}$ values of $77.01{\pm}3.13{\sim}89.96{\pm}3.08{\mu}g/mL$. The results suggest that standardization of 3,5-DCQA in AGEs using HPLC-UV analysis would be an acceptable method for the development of health functional foods.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.324-332
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• 2016

The objective of this study was to investigate the antioxidant activity of Korean yam (Dioscorea batatas $D_{ECNE.}$) by different extraction solvents including 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high $L^*$ value and $H^{\circ}$ value, which were $81.64{\pm}2.59$ and $83.36{\pm}0.15$, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract ($37.62{\pm}0.88mg\;CAE/g$), 70% ethanol extract ($43.38{\pm}0.66mg\;CAE/g$) and CM extract ($67.17{\pm}0.12mg\;CAE/g$), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

• Journal of the Ergonomics Society of Korea
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• v.21 no.2
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• pp.71-86
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• 2002

This study's purpose is to gain basic data for the factory automation of manufacturing custom-made girdles. For this study , obese women in their 30s and 40s was experimented through direct measuring and by the 3D scanner, by means of which the proportions of the subject's body was measured. Based upon the results of this experiment, individually designed girdles were made. In order to gain the basic data for the factory automation of manufacturing custom-made girdles, the patterns and the clothing pressure and the feeling of wearing such girdles were analyzed. This study can be summarized as follows: The material properties and the designs of existing functional girdles in the market were studied thoroughly, and the subject were required to wear those existing girdles. On the basis of this result, the experimental girdles were designed and produced which could serve well the subject's intension. The experimental girdles were of the basic long-type in order to apply to all sorts of girdles, and they were produced according to the style and pattern of the existing grading system. The second experiment was conducted by applying the subject's body measurements. Due to the elasticity of the material, in girdles the smaller measurements were to be used in this second experiment were: 80% of waist size, 84% of the hip and 85% of the thigh. To determine the length of the girdles, the same measurements were applied. The test results of the feeling of wearing the experimental girdles showed that the second, custom-made experimental girdles were better. According to the test results of the clothing pressure, the second experimental girdles(custom-made girdles) marked the higher pressure than the first on every part of the body, especially on the hips and thighs. Thus, it can be said that the second experimental girdles are better than the first in lifting up the hips. It is expected that the design methods developed in this study can be utilized as basic resources for the factory automation system of manufacturing custom-made girdles.