• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.431-436
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• 2020

Information service organizations that provide science and technology information with a relatively short information life cycle for free or paid are in need of reflecting rapidly changing user needs and behaviors and grafting the latest technologies. The purpose of this study is to derive improvements for each system by comparing and analyzing general recognition of science and technology information users' domestic and foreign science and technology information sites and importance by science and technology information attributes. A total of 816 users of science and technology information participated in the online survey, and the collected data were analyzed by quantitative methods including IPA (Importance Performance Analysis) technique. The importance was evaluated by the impact value calculated through regression analysis. As a result of data analysis, the general recognition of users on science and technology information sites was relatively high in national science and technology information services, and Google Scholar and Science Direct were also high. Google Scholar was found to have more strength than improvement. A better understanding of the user's preferred system is a good driving force for improving the lack of existing systems. It is necessary to improve the information retrieval of the science and technology information service system, that is, to improve the search speed and functions, and also to improve the user interface with improved convenience and usability.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.2
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• pp.125-136
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• 1997

Digestion of a municipal wastewater sludge by the anaerobic sequencing batch reactor(ASBR) was investigated to evaluate the performance of the ASBR process at a critical condition of high-solids-content feed. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 gVS/L/d at $35^{\circ}C.$ The main conclusions drawn from this study were as follows: 1. Digestion of a municipal wastewater sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge. The ASBRS with 3- and 4-day cycle period showed almost identical high digestion performances. 2. No adverse effect on digestion stability was observed in the ASBRS in spite of withdrawal and replenishment of $30\%\;or\;40\%$ of liquid contents. A conventional anaerobic digester could be easily converted to the ASBR without any stability problem. 3. Flotation thickening occurred in thicken step of the ASBRS throughout steady state, and floating bed volume at the end of thicken period occupied about $70\%$ of the working volume of the reactor. Efficiency of flotation thickening in the ASBRS could be comparable to that of additional gravity thickening of a completely mixed digester. 4. Solids were accumulated rapidly in the ASBR during start-up period. Solids concentrations in the ASBRS were 2.6 times higher than that in the completely mixed control reactor at steady state. Dehydrogenase activity had a strong correlation with the solids concentration. Dehydrogenase activity of the digested sludge in the ASBR was 2.9 times higher than that of the sludge in the control reactor, and about 25 times higher than that of the subnatant in the ASBR. 5. Remarkable increase in equivalent gas production of $52\%$ was observed at the ASBRS compared with the control reactor in spite of similar Quality of clarified effluent from the ASBRS and control reactor. The increase in gas production from the ASBRS was believed to be combined results of accumulation of microorganisms, higher driving force applied, and additional long-term degradation of organics continuously accumulated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.72-72
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• 2012

Lithium rechargeable batteries have been widely used as key power sources for portable devices for the last couple of decades. Their high energy density and power have allowed the proliferation of ever more complex portable devices such as cellular phones, laptops and PDA's. For larger scale applications, such as batteries in plug-in hybrid electric vehicles (PHEV) or power tools, higher standards of the battery, especially in term of the rate (power) capability and energy density, are required. In PHEV, the materials in the rechargeable battery must be able to charge and discharge (power capability) with sufficient speed to take advantage of regenerative braking and give the desirable power to accelerate the car. The driving mileage of the electric car is simply a function of the energy density of the batteries. Since the successful launch of recent Ni-MH (Nickel Metal Hydride)-based HEVs (Hybrid Electric Vehicles) in the market, there has been intense demand for the high power-capable Li battery with higher energy density and reduced cost to make HEV vehicles more efficient and reduce emissions. However, current Li rechargeable battery technology has to improve significantly to meet the requirements for HEV applications not to mention PHEV. In an effort to design and develop an advanced electrode material with high power and energy for Li rechargeable batteries, we approached to this in two different length scales - Atomic and Nano engineering of materials. In the atomic design of electrode materials, we have combined theoretical investigation using ab initio calculations with experimental realization. Based on fundamental understanding on Li diffusion, polaronic conduction, operating potential, electronic structure and atomic bonding nature of electrode materials by theoretical calculations, we could identify and define the problems of existing electrode materials, suggest possible strategy and experimentally improve the electrochemical property. This approach often leads to a design of completely new compounds with new crystal structures. In this seminar, I will talk about two examples of electrode material study under this approach; $LiNi_{0.5}Mn_{0.5}O_2$ based layered materials and olivine based multi-component systems. In the other scale of approach; nano engineering; the morphology of electrode materials are controlled in nano scales to explore new electrochemical properties arising from the limited length scales and nano scale electrode architecture. Power, energy and cycle stability are demonstrated to be sensitively affected by electrode architecture in nano scales. This part of story will be only given summarized in the talk.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.57-67
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• 2020

Recently, smart cities are attracting attention as a solution for a plethora of urban problems, including transportation, environment, safety, and energy. However, despite a substantial body of research dealt with the concept, trends, policy, and legal institutions of smart cities, few researchers have examined how the smart city services influence the cities from the dynamic perspective that considers the entire cycle of a city, including its growth, stagnation, and decline. Thus, it is vital to understand how the city changes with time from the view that a city is a system of sub-elements-population, industry, transportation, environment, housing, and land-closely interacting together. Within this context, this study explores how the urban dynamics of Anyang-city develop for the long term using the System Dynamics method and analyzes the effect of smart city project investment on the dynamics of Anyang-city. According to the result, Anyang-city is a "mature and stable" type, and its population is expected to decrease slowly by 2040. Specifically, the Anyang-city population will be reduced to 553,000 by 2030. It was analyzed that the number will decrease to 543,000 by 2040. It was also found that the investment in smart city projects in Anyang, based on the Plan for Anyang Smart City, would have the following effects: easing population decline, increasing number of businesses, improving urban safety index, and increasing average driving speed. The population will grow by 4,000 and the number of businesses will increase by 761 than before budget investment. The result of this paper is expected to contribute to identifying and predicting the effect of smart city policies from a long-term perspective.

• Journal of Korea Water Resources Association
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• v.53 no.11
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• pp.1039-1047
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• 2020

Atmospheric rivers, which transport large amount of water vapor from mid-latitude to the inland, are an important driving force of water cycle and extreme hydrologic phenomenas. The main objective of this study is to analyze the hydrological impact of the AR landfalls on the Korean Peninsula in 2000 - 2015. The result showed that the AR is closely related to the characteristics of precipitation, water level and runoff in the Korean Peninsula. The landfalls of the AR affected about 57% of annual precipitation on the Korean Peninsula, and had a greatest impact on the summer rainfall. It also affected the water level and runoff at the five major rivers of Korea, and water levels exceeding the thresholds of flood warning were observed when the AR landed. Moreover, it was found that the runoff above the third quartile with AR landfalls. These results suggest that the AR not only has a significant influence on the hydrological characteristics of the Korean Peninsula, but also have a close relationship with the extreme hydrological events like floods. The results of this study are expected to be used as the reference for the analysis of the impact of the AR on the various fields in the Korean Peninsula.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.163-170
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• 2006

Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. For the purpose of cutting down the expense of government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1161-1175
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• 2018

An unexpected event could be easily followed by a large secondary accident due to the limitation in sight of drivers in road tunnels. Therefore, a series of automated incident detection systems have been under operation, which, however, appear in very low detection rates due to very low image qualities on CCTVs in tunnels. In order to overcome that limit, deep learning based tunnel incident detection system was developed, which already showed high detection rates in November of 2017. However, since the object detection process could deal with only still images, moving direction and speed of moving vehicles could not be identified. Furthermore it was hard to detect stopping and reverse the status of moving vehicles. Therefore, apart from the object detection, an object tracking method has been introduced and combined with the detection algorithm to track the moving vehicles. Also, stopping-reverse discrimination algorithm was proposed, thereby implementing into the combined incident detection processes. Each performance on detection of stopping, reverse driving and fire incident state were evaluated with showing 100% detection rate. But the detection for 'person' object appears relatively low success rate to 78.5%. Nevertheless, it is believed that the enlarged richness of image big-data could dramatically enhance the detection capacity of the automatic incident detection system.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.11-17
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• 2022

Currently, the income and funds of the local economy are flowing out to the metropolitan area, and talented people, the driving force for regional development, also gather in the metropolitan area, and the local economy is facing a serious crisis. Local currency is issued by local governments and is a currency with auxiliary and complementary functions that can be used only within the area concerned. In order to revitalize the local economy, as local governments have focused their attention on the introduction of local currency, studies on the issuance and use of local currency are continuously being conducted. In this study, by using big data from data materials such as portals and SNS, the consumer image of local currency issued in local governments was identified through big data analysis, and based on the research results, the issuance and operation of local currency was conducted. The purpose is to present implications for The results of this study are as follows. First, by inducing local consumption through the policy issuance of local currency, it is showing the effect of increasing the economic income of the region. Second, local governments are exerting efforts to revitalize the economy and establish a virtuous cycle system for the local economy by issuing and distributing local currency. Third, the introduction of blockchain technology shows the stable operation of local currency. With academic significance, it was possible to grasp the changed appearance and effect of local currency through big data analysis and the policy direction of local currency.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.293-299
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• 2022

Recently, various stakeholder are interested in microplastic to cause pollution of the marine's ecosystem and effort to conduct study of product's life cycle to reduce pollution of marine's ecosystem. The micorplastic refer to materials of the nano- to micro- sized units and it can be classified into primary and secondary. The primary microplastic mean the manufactured for use in the specific field such as the microbead of the cosmetic or cleanser. also, secondary mean the unintentionally generated during use of the product such as the textile crumb by the doing the laundry. Tire and Road Wear Particles(TRWPs) are also defined as secondary microplastic. Typically, TRWPs are created by friction between the tread compound's rubber of the tire and the surface of the road du ring the driving cars. Most of the generated TRWPs exist on the roadside and some of them were carried to marine by the rainwater. In this study, we perform the quantitative analysis of the TRWPs existed in fine dust at the roadside. So, we collected the dust from the roadside in Chungcheongnam-do's C site with a movement of 1,300 cars per the hour. The collected samples were separated according to size and density. And shape analysis was performed using the Scanning Electron Microscope(SEM). We were possible to discover a lot of TRWPs at the fine dust of the 100 ± 20 ㎛. And we analysis it u sing the Thermo Gravimetric Analysis(TGA) and Gas Chromatography/Mass Spectrometer(GC/MS) for the quantitative components from the tire. As a result, it was confirmed that TRWPs generated from the roadside fine dust were included the 0.21 %, and the tire and road components in the generated TRWPs consisted of the 3:7 ratio.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.321-346
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• 2019

The cycle of human life has a limited time to death. Everyone cannot help but think how to live in the limited time and then they try to reach toward their happiness. Their pursuit for the happiness gives rise to the new trend called 'Well-bing'. Generally speaking, it means to eat well, to feel their own satisfaction with their lives and to spend a time on doing what they want to do. However, considering their current lives which are tough and harsh, it could be impossible for them to accomplish the well-being stated above. From this point, it is natural to think what real well-being means. Its real meaning would be understood by identifying its cause if well-being is the way to happiness. Based on the thesis stated above, let me look into the desire of human being. It has both side; it should be eliminated or overcome as a deficiency and disability in human life while it could be an driving force to let the human being keep their lives. They can find the real meaning of well-being and their happiness can be realized through the control of their desires. Above all, according to the control for them, they can accomplish their happiness or fail to do it. The trend of well-being can be kept in our culture when moral value is reflected to the well-being. Finally, it orients to the purpose of happiness. It also means that everyone shares moral and positive value one another in the process of challenge to achieve their goals. In order to realize it, they should be satisfied with their current situation and have a balance with everything related to themselves.