• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.328-332
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• 2011

After preparation of acetone, ethanol, methanol, and water extracts (10 g/300 mL) of dried persimmon (Diospyros kaki cv. Fuyu) flower-buds, total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) RSA, reducing power (RP), and tyrosinase inhibitory activity of the extracts were evaluated. The methanol extracts produced the highest TPC (113.39 mg gallic acid equivalents/g), DPPH RSA ($IC_{50}=40.25\;{\mu}g/mL$), ABTS RSA ($IC_{50}=58.17\;{\mu}g/mL$) and RP ($IC_{50}=69.43\;{\mu}g/mL$) activities while the water extracts generated the lowest values. The ethanol extract showed the highest tyrosinase inhibitor activity (88.90%) at a concentration of 1 mg/mL. These results indicated that persimmon flower-buds may be a useful source of natural antioxidants.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.281-288
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• 2008

Cake resistance is influenced by floc size deposited on membrane surface. Enlarging floc size can reduce cake resistance. The small particles are enlarged by coagulation and flocculation process in conventional mixing tank at membrane filtration system. Fully-grown flocs for reducing the cake resistance, however, are ruptured while passing through a pump. In light of this fact, this study aims to experimentally look at the reaggregation phenomenon of mixing system. In addition, reaggregation phenomenon of mixing system is compared with first-aggregation of in-line injection system in which coagulant is injected just before a pump. These results suggest that first-aggregation of in-line injection system is better than reaggregation of mixing system for G-value above $3100sec^{-1}$. Since G-value in pipe of actual membrane filtration system are usually larger than $3100sec^{-1}$. The performance of in-line injection system is expected to be better than the conventional mixing tank system.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.125-134
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• 2014

6 sigma is a management innovation strategy which improves most of all managerial processes including transactional and project based operations such as marketing, purchasing, accounting, and construction. Even though 6 sigma is trying to solve problems from the customer's viewpoint in the scientific manner, project leader feels some difficulties in implementation because of several reasons. Especially the difficulties are prevalent in construction site. This paper investigates the cause of the difficulties through questionnaires, analyzes the investigation results, and verifies the critical success factors of 6 sigma implementation. Factor analysis has been usually employed in reducing quantity of data and summarizing information chaos. In this study, several variables from questionnaires are grouped into just only four factors by the process of factor analysis. The critical success factors are extracted as project management system, implementation mechanism, site condition, and project ownership. Some ideas for each individual success factor are suggested, which are expected to be useful in successful implementation of 6 Sigma in construction site.

• IE interfaces
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• v.4 no.2
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• pp.67-72
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• 1991

CWM(Coal Water Mixture) is a mixed fuel that consists of coal, water and additives. The main advantages of CWM are reducing the oil consumption and the air pollution materials such as flyash, dirt, and $SO_x$. This paper presented a case study for the economic feasibility analysis of changing an existing coal-oil power plant to a CWM power plant. The economic analysis of changing a coal-oil power plant to a CWM power plant was based on the total annual incremental costs of two power plants. We found that this project was economically and environmentally acceptable.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.279-282
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• 2011

최근 기후변화에 의한 기상현상은 국지성 집중호우, 돌발홍수 등을 발생시켜 많은 인명과 재산의 피해를 가져오고 있다. 특히, 도시집중 현상으로 택지 및 시설부지의 부족현상이 가중됨으로써 하천범람 구역이나 홍수우려가 있는 저지대까지 도시화가 이루어짐으로써 치수상 안전도가 상대적으로 저하되고 있는 한편, 도시유역에서의 집중호우로 인한 홍수피해는 다른 지역에 비해 상대적으로 피해규모가 증대되고 있다. 또한, 최근 도시지역에 홍수피해를 유발하고 있는 강우의 특징은 단시간에 많은 강우가 집중하여 발생하는 국지성 집중 호우로 침수피해를 가중시키는 경향이 있으므로 배수시설 설계 시 이러한 강우의 특성과 도시유출 특성에 대한 고려가 필요하다. 이에 본 연구에서는 최근 침수가 잦은 부산 센텀지구를 대상으로 모형을 구축하여 기존배수체계의 배수능력을 초과하는 집중호우 발생 시 침수피해를 저감하기 위한 지하저류조의 용량을 산정하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.43.2-43.2
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• 2010

Most of previous methods for the dispersions of carbon nanotube were achieved by various chemical functionalizations. In this study, however, we generated highly water dispersed carbon nanofibers by altering intrinsic materials property only, such as crystallinity of outer layers of carbons, without chemical treatment. Although most of chemical functionalization requires acidic treatment and may degrade their chemical functions by interacting with other molecules, suggested strategy demonstrated a simple but chemically non-degradable carbon nanotube for the application of various medical applications, such as drug delivery system and implant coatings.Furthermore, protein adsorption was increased by the reducing surface crystalinity since outer activated surface induced more adsorption of oxygen and eventually greater protein adsorption than pristine carbon nanofibers.

• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.23-30
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• 2015

Processing of medicinal plants is one of the processing methods for reducing of toxicity or improving of effect on medicinal plants. In this study, we studied the changes in the constituents and antioxidant activity in accordance with the processing conditions by the salt water of Citrus unshiu Markovich. Changes in antioxidant activity was measured by the DPPH method and changes in the components were analyzed by high performance liquid chromatography. As a result, the content of the main constituents (narirutin, hesperidin) and total polyphenol were increased by increasing the concentration of salt water. Moreover, antioxidant activity was increased gradually in proportion to the increase of the total polyphenol content.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.673-679
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• 2008

The representative microorganism of autotrophic denitrification using sulfur granule, oxidizes the reduction from S and performs denitrification by reducing $NO_3{^-}-N$ to $N_2$ gas. The sampling of autotrophic denitrification microorganisms has been performed from foreshore sludge, condensed sludge, and active sludge, but the analysis of autotrophic denitrification microbial community characteristics has been lacking. Based on the separation and identification of each sample using the PCR and DGGE methodologies, many types of sulfuric microorganisms and autotrophic denitrification microorganisms were found.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.111-123
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• 2004

Recently, though damage caused by intensive rainfall and typhoon happens frequently, we could not forecast or predict a disaster, due to the difficulty of obtaining exact information about it. For efficient disaster management, the most urgent need is the preparation of a flood forecast-warning system. Therefore, we need to provide a program that has the ability of inundation analysis and flood forecast-warning using a geographic information system, and using domestic technology rather than that from foreign countries. In this research, we constructed a FDMS(Flood Disaster Management System) that is able to analyze real-time inundation data, and usins the GIS(Ceographic Information System) with prompt analyzing of hydrologic-topographical parameters and runoff-computation. Moreover, by expressing inundation analysis in three-dimensions, we were able to get to the inundation area with ease. Finally, we expect that the application of this method in the (food forecast-warning system will have great role in reducing casualties and damage.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.91-96
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• 2005

This study was performed for the research on the method for reducing non-point pollutant with the gabion which was made of gravel-packed plastic frame, and for the characterization of gabion adsorbing pollutant. The result showed that the concentrations of suspended solid in turbid water were reduced to $77.7{\sim}84.7%$ when the water was flowing through the gabion. The uniformity coefficients on the grain size accumulation curves of the adsorbed pollutant were larger on the large grain size gabion than those on the small grain size gabion, and the coefficients of curvature were smaller on the large grain size gabion than those of the small grain size gabion. The adsorption rates were dependent on the grain size of packed gravel. The rates were smaller on inlet and outlet than those on middle place on the series of gabion.