• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.323-324
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• 2012

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.182-184
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• 2000

There are several facilities in Kochang distribution test center such as artificial fault generator(AFG), new distribution automation system(NDAS), communication networks (wireless and optic), lumped constant circuit, switches for distribution automation, overhead and underground distribution line. We have been field testing on remote control, data acquisition. remote metering, feeder automation and so on for distribution automation using those equipment.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.23-33
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• 1999

This study is to investigate the effect of C factor errors on the analysis of water distribution systems. For this purpose, an artificial distribution network and a real distribution network were selected as the study networks. Results are as follows. 1. The C factor of a pipe which has small velocity didn't give significant effect on the analysis of a water distribution system. 2. The effect of decreased value of C factors give more influence on the analysis of water distribution systems than that of the increased values. 3. For the C factor calibration, errors of the residual water heads as well as those of the head losses should be considered together. 4. In the analysis of water distribution systems, changes of C factors can give influences only on the nodes which locate behind the pipe. Therefore, this characteristics should be considered in the selection of nodes for the measurement of water heads.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.2
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• pp.146-152
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• 2011

Underwater CCTV camera systems are increasingly replaced the traditional net approach of assessing the species, numbers and aggregation patterns of marine animals distributing around the artificial reefs installed in the inshore fishing grounds, in particular, in relation to the biological investigation of behavior and distribution patterns of target fishes. In relation to these needs, we developed a multi-directional underwater CCTV camera system to use in detecting and tracking marine animals in the artificial reef ground. The marine targets to be investigated were independently tracked by using a camera module toward the bottom and four camera modules installed in the interval of $90^{\circ}$ in horizontal plane and inclination of $45^{\circ}$ in vertical plane of the CCTV system without the overlap of video frames by each camera module. From the results of several field tests at sea, we believe that the developed multi-directional underwater CCTV camera system will contribute to a better understanding in evaluating the effect of artificial reefs installed in the inshore fishing grounds.

• Journal of Biomedical Engineering Research
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• v.29 no.3
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• pp.173-178
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• 2008

Recent advancements in the electrospinning method enable the production of ultrafine solid and continuous fibers with diameters ranging from a few nanometers to a few hundred nanometers with controlled surface and morphological features. A wide range of biopolymers can be electrospun into mats with a specific fiber arrangement and structural integrity. These features of nanofiber mats are morphologically similar to the extracellular matrix of natural tissues, which are characterized by a wide pore diameter distribution, a high porosity, effective mechanical properties, and specific biochemical properties. This has resulted in various kinds of applications for polymer nanofibers in the field of biomedicine and biotechnology. The current emphasis of research is on exploiting these properties and focusing on determining the appropriate conditions for electrospinning various biopolymers for biomedical applications, including scaffolds used in tissue engineering, wound dressing, drug delivery, artificial organs, and vascular grafts, and for protective shields in specialty fabrics. This paper reviews the research on biomedical applications of electrospun nanofibers.

• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.280-288
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• 2019

A submerged breakwater is one of the coastal structures used to reduce wave energy and coastal erosion. However, a submerged breakwater has a negative aspect in that a strong rip current occurring around an open inlet due to a difference in mean water levels at the front and rear sides of the structure leads to scouring. Such scouring has a bad effect on its stability. In order to eliminate this kind of demerit, this study investigated an artificial reef of the overflow type with openings. We also developed a program where the flows around the artificial reef of the overflow type could be analyzed numerically. An unstructured grid system was used to cover the various geometries, and the level set method was applied to treat the movement of the free surface. To verify these numerical schemes, hydraulic physical tests were performed on the submerged breakwater and double breaking type artificial reef. Then, the wave height and velocity distribution around the reef were examined using the experimental results. Comparisons between the results of hydraulic and numerical tests showed reasonable agreement.

• The Journal of Industrial Distribution & Business
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• v.14 no.2
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• pp.21-33
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• 2023

Purpose: After using the Internet, the world is changing through several paradigms, and the retail industry, which is essential to living in the world, is also changing rapidly. In this review paper, the requirements that the retail industry should consider and prepare in accordance with the rapidly changing paradigm were reviewed according to the current situation of the times. Research design, data, and methodology: It is a review of technological development using PRISMA flow diagram, retail change, and necessity in April 2022, and a review of the digital environment to be applied to the retail industry in the future. Results As the current situation and changes of retail, and the development of IT technology, reviews on the retail business applying the 4th Industrial Revolution, the Internet of Things and artificial intelligence were collected, and the direction of the retail industry was suggested. Conclusions: The direction for the retail industry in preparation for developing technologies was presented. In addition, this study is a review paper that suggests the need for research on active introduction of new technologies to the beauty market that is very close to human life and economically helpful as IT technology for the 4th industrial revolution develops rapidly.

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.281-288
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• 2006

The purpose of this study was to investigate the distribution status and environmental index of the naturalized plants and exotic plants In the 16 sites in Gayasan National Park from March to October 2004. The exotic plants were recorded as 88 taxa, 39 families, 72 genera, 82 species, 5 varieties and 1 form. The naturalized plants among the exotic plants were certified as 47 taxa. The Naturalized Ratio (NR) was 4.06% and the Urbanization Index (UI) was 17,74% in area of Gayasan National Park. The naturalized plants were distributed around the region that had accepted artificial disturbance however, it was so difficult to identify distribution of naturalized plants in the conserved area as well as natural vegetation without artificial turbulence. The naturalized plants appeared as almost all speciesas 37 taxa (72%) which both originated from Europe and North America. Although a national degree for integrated management plans of exotic plants is needed, distribution and steady management of exotic plants in Gayasan National Park are playing an important role in conservation and protection of natural species.

• Composites Research
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• v.28 no.3
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• pp.89-93
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• 2015

This study analyzes the transplanting parts used as the graft of artificial knee joint. The low elastic titanium alloy is applied to clear up the stress shield effect. The simulation analysis is carried about the stress distribution of the transplanting parts. The correlation with frame is inferred and investigated through the equivalent stress distribution of titanium alloy due to elastic modulus. The stress of the transplanting parts decreases as the elastic modulus decreases at the first time. It decreases greatly near the stress of 46 GPa and increases again. Because the stress happened at the transplanting parts decreases, more stress is applied on the frame. This phenomenon is the stress shield effect. The result of this study can be thought to be necessary to develop the safe design of composite material.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.89-97
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• 2018

The purpose of this reaserch is to analyze the charateristics of water quality in space through the operation of ARA River in Artificial Rivers of the Brackish Water Zone. The spatial distribution measured water temperature and salt levels for the surface, middle and deep layers by dividing the four areas of Incheon, Sicheon, Gyeyang and Gimpo. Water temperature did not vary much by water depth and branch, and its purpose is to maintain stable water environment through correlation analysis and operation. To examine the temporal and spatial distribution patterns of the Arachon, we measured DO on the Incheon branch, Sicheon, Gyeyang and Gimpo branch twice a month, and on the surface, the temperature level, The water temperature did not vary much by depth and location, and the water temperature in January and March tended to rise from Incheon to Gimpo, with the average difference of 1.1 degrees during the same period. The salinity difference between Incheon and Gimpo sites was 3.3 psu deep and 5.4 psu deep. In particular, floodgates from July to September are found to be less than 10psu overall, which is considered to be a gas due to the effects of floods and the inflow of Gulpo Stream. D.O. is located in some areas due to summer rains. The hypoxic layer has been identified.Analysis of seasonal data shows that water temperature and DO are strongly correlated in autumn. It was found that the water temperature and salt levels in the fall showed a weak correlation.