• Korean Journal of Environment and Ecology
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• v.7 no.2
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• pp.241-251
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• 1994

Use impacts on environmental deteriorations were studied on the four major trails and a campsite of Tokyuksan National Park in 1993. The entire width, bare width, maximum depth and slope of trail as the trail condition were significantly greater on the more heavily used trail. Percentages of rock-exposed, deepening, root-exposed points as the deterioration types of trail which were surveyed at the total of 106 points were higher and trail conditions were significantly different from those of non-deteriorated points. On the Paekryon trail, the damaged area more severe than Class 4 reaches about 910$m^2$/km and the use impact and deterioration on campsites were accelerated. The dominant trees of the the upper and lower layer in trail edge vegetation could be Quercus serrata and Acer pseudo-sieboldianum for Paekryon trail, Q. mongolica and Tripterigium regelii for the other trails. A. pseudo-sieboldianum, Q. serrata, Rhus trichocarpa, Fraxinus sieboldiana, Lespedeza maximowiczii, Symplocos chinensis for Pilosa were classified for tolerant species to use impacts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.4
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• pp.467-473
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• 2020

Recently, the number of traffic accidents has also increased with the increase in the penetration rate of cars in Korea. In particular, not only inter-vehicle accidents but also human accidents near crosswalks are increasing, so that more attention to traffic safety around crosswalks are required. In this paper, we propose a system for predicting the safety level around the crosswalk by recognizing an approaching vehicle and estimating the speed of the vehicle using NVIDIA Jetson Nano-class edge devices. To this end, various machine learning models are trained with the information obtained from deep learning-based vehicle detection to predict the degree of risk according to the speed of an approaching vehicle. Finally, based on experiments using actual driving images and web simulation, the performance and the feasibility of the proposed system are validated.

• Journal of Fashion Business
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• v.28 no.4
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• pp.167-178
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• 2024

With the advent of the ICT era in the 4th Industrial Revolution era, cutting-edge industries in accordance with changing trends of the time, the MZ generation is leading a new consumer culture with a digital platform-based lifestyle. As such, wearable devices are leading popularization of the market, the need for product development and research that goes beyond simply combining high technology and combines user-centered functions and designs is emerging. Therefore, the purpose of this study was to analyze the functional mechanism of wearable devices according to consumption value of the MZ generation, focusing on wearable devices currently being commercialized in the digital transformation era, their characteristics were also derived. The research method for this purpose involved classifing wearable devices into notification, information, and content types according to their functional mechanisms and examing them. As a result of the research, characteristics of identity, collaboration, customization, and content were derived, I was is thought that they could interact with situational awareness to suit the situation and purpose. They are closely related. They could make social responsibility and sustainable efforts beyond the brand's image and profit pursuit. As the consumption value of the MZ generation, a new consumer class, is highlighted, it is essential to segmenting and analyzing user-centered functions and content, not simply combining cutting-edge technologies this study is significant in that it provides essential data for continuous development of wearable devices and the establishment of successful marketing strategies.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.173-177
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• 2020

In this study, the side doors of mid-size sedan vehicles of models A and B which are currently prone to rollover accidents are compared with each other by the structural analyses. As a result of the structural analysis, both models showed the maximum deformation at the point of overturning or impact load, and the model A of the two models was able to withstand greater impact load compared to the model B. In addition, the maximum stress happened at the door edge, and model B was 2.5 times more stressed than model A. In the accident of a crash, model A, which has the smaller maximum stress, is able to withstand greater impact loads than model B. Since model B has a larger deformation than model A, it is considered to be more dangerous than model A in the side impact accident. By applying the impact analysis of automotive side door by the class of vehicle, the study result at this paper is considered to be favorable as the convergent research material which can apply the aesthetic design.

• Journal of the Korean Society of Costume
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• v.30
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• pp.295-306
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• 1996

A large quantity of exhumed clothing found for recent 20 years has becom-e the material for making a concrete clarification of the structure of clothing in the Chosun dynasty. Exhumed clothing means the clothing found in the coffin when the grave of the ancestor buried several hundred several hundred years ago is removed to another pla-ce and it is almost comprised of ordinary clothes of the grave-owner not mourning clothes as well as clothing and ornaments in the period between the 15th cen-tury and th 19th century. This research is intended to inquire into the kind of chimas in the 16th century before the Imjin Japancese Invasion of Korea during 1592-1598. The after effect of the Imjin Japanese In-vasion was generally reflected in clothing them and the structure of clothing in the Chosun dynasty began to overshadew its di-chotomy with the Imjin Japanese I vasion of Korea as the point. Accordingly this research is concerned with the study of the chima system of the early Chosun dynasty which shows that there is a common point of the identical form though clothing was exhumed in different graves. Therefore it was possible to grasp women's clothing that was fashionable at that time The object for research is the women in the upper class of the 16th century whose representative characteristics are depicted as follows: 1. Women in the upper class wore the splendid clothing similar to the ordinary clothing of court ladies. 2. The division of ordinary chima and ceremonial chima appeared in the concrete. 3. Ceremonial chima had its extra width and length and exhibited its exaggerated silhouette. in particular it had a various forms of over-pleats made at its center front which play a role in supplementing discomfort in walking. This associate bustle and crinolin styles through which the modern design of clothing can be glimpsed. 4. The opposite phenomenon was shown that has been perceived up to now such as folding at the right plain seam the treatment of the edge-and the like. 5. The elaboration of manual needlework shows the culmination of women's workmanship.

• Korean Journal of Human Ecology
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• v.6 no.1
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• pp.97-109
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• 1997

Sean means a narrow cloth added to the edge of costume or cushion. At the beginning, Seon was originated to prevent from fraying warp of cloth or wearing out of cloth. However, with the progress of clothing culture, it is used to satisfy the human desire of decoration and enhance the function of costume. The Seon appeared on costumes of Ming dynasty was simple compared to that of the period preceeding it. The position of Seon was mostly at neckline, end of sleeves and hemline. The width of Seon also was quite monotonous and lacks of varieties. The patterns of Seon were limited to ax, cloud and dragon and cloud and chinese phoenix. And the colors used were also limited to four colors, namely Blue, Red Crimson and Black. In Ming dynasty, the same colors of Seon as those of the costume were more preferably used, while different colors of Seon were used in the previous era. The reason why Seon in Ming dynasty show simple design and use the same colors as those of the costume was due to Ming dynasty's desire to represent and to enhance her castic political structure. The need for class distinction was expressed through the pattern rather than the colors of the costumes themselves. While, in Ming dynasty, Bo(補) which was attached to the breast and the shoulders was used to represent the social class because it could be easily distinguished. In Ming dynasty, to stress Bo and to make Seon less conspicuous, Seon became simple and the colors of Seon were same as those of the costumes avoiding strong contrast in style and colors.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.344-350
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• 2013

The purpose of this study is to examine the structural stability of a low speed 200 W class gyromill type vertical axis wind turbine system. For the analysis, a commercial code is adopted. The pressure distribution on the rotor blade surface is examined in detail. In order to perform unidirectional FSI(Fluid-Structure Interaction) analysis, the pressure resulted from CFD analysis has been mapped on the surface of wind turbine as load condition. The rotational speed and gravitational force of wind turbine are also considered. The results of FSI analysis show that the wind turbine reveals an enough structural margin. The maximum structural displacement occurs at trailing edge of blade and the maximum stress occurs at the strut.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.465-465
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• 2009

Wind power is one of the most reliable renewable energy sources and the installed wind turbine capacities are increasing radically every year. Although wind power has been favored by the public in general, the problem with the impact of wind turbine noise on people living in the vicinity of the turbines has been increased. Low noise wind turbine design is becoming more important as noise is spreading more adverse effect of wind turbine to public. This paper demonstrates the design of 10 kW class wind turbines, each of three blades, a rotor diameter 6.4m, a rated rotating speed 200 rpm and a rated wind speed 10 m/s. The optimized airfoil is dedicated for the 75% spanwise position because the dominant source of a wind turbine blade has been known as trailing edge noise from the outer 25% of the blade. Numerical computations are performed for incompressible flow and for Mach number at 0.145 and for Reynolds numbers at $1.02{\times}10^6$ with a lift performance, which is resistant to surface contamination and turbulence intensity. The objective in the low design process is to reduce noise emission, while sustaining high aerodynamic efficiency. Dominant broadband noise sources are predicted by semi-empirical formulas composed of the groundwork by Brooks et al. and Lowson associated with typical wind turbine operation conditions. During the airfoil redesign process, the aerodynamic performance is analyzed to minimize the wind turbine power loss. The results obtained from the design process show that the design method is capable of designing airfoils with reduced noise using a commercial 10 kW class wind turbine blade airfoil as a basis. The new optimized airfoil clearly indicates reduction of total SPL about 3 dB and higher aerodynamic performance.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.217-227
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• 1990

The purpose of this study was to evaluate the marginal leakage of esthetic restorative materials according to the filling method in class V cavities. 60 cavities were prepared on buccal surface for dye penetration test and divided into 5 experimental groups according to the filling methods of esthetic materials: group 1 was filled with glass ionomer cement, group 2, 3 and 4 were filled with the chamfer, knife edge and butt joint shaped glass ionomer cement respectively and silux plus/scotchbond 2$^{(R)}$ by sandwich technique, group 5 was lined with Dycal$^{(R)}$ and filled with silux plus/scotchbond 2$^{(R)}$ by bulk filling technique. All the specimens were then thermocycled in a range of $4^{\circ}C-60^{\circ}C$ by and immersed in 2% methylene blue dye solution for 24 hours, and sectioned mesiodistally with carborundum disk into two parts under water spray. All the specimens were observed at the occlusal and gingival margins and statistical analysis was performed. The obtained results were as follows : 1. At the occlusal margins, group 2, 3, 4 and 5 showed less marginal leakage than group 1 (p<0.05) and there were not significant differences among group 2, 3, 4, and 5. 2. At the gingival margins, group 5 showed the least marginal leakage and group 4 and 5 showed less marginal leakage than group 1, 2 and 3 (p<0.05). 3. In the laminated groups, group 4 showed less marginal leakage than group 2 and 3 at the gingival margins. 4. In comparison to the occlusal and gingival margins, all groups showed less marginal leakage at the occlusal margins than at the gingival margins (p<0.05).

• Journal of Wind Energy
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• v.14 no.4
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• pp.50-56
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• 2023

With the abnormal weather phenomena caused by global warming, the frequency and intensity of lightning strikes are increasing, and lightning accidents are becoming one of the biggest causes of failures and accidents in offshore wind turbines. In order to secure generator operation reliability, effective and practical measures are needed to reduce lightning damage. Because offshore wind turbines are tall structures installed at sea, the possibility of direct lightning strikes is very high compared to other structures, and the role of surge protection devices to minimize damage to the electrical and electronic circuits inside the wind turbine is very important. In this study, a varistor, which is a key element for a class 1 surge protection device for direct lightning protection, was developed. The current density was improved by changing the varistor composition, and the distance between the electrode located on the varistor surface and the edge of the varistor was optimized through a simulation program to improve the fabrication process. Considering the combined effects of heat distribution, electric field distribution, and current density on the optimized varistor surface, silver electrodes were formed with a gap of 0.5 mm. The varistor developed in this study was confirmed to have an energy tolerance of 10/350 ㎲, 50kA, which is a representative direct lightning current waveform, and good protection characteristics with a limiting voltage of 2 kV or less.