• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.23-29
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• 2019

In general, pipe laying works are performed by constructing underground facilities such as pipes and then refilling the rest of the area with sand or soil. However, there are many problems in the compaction process such as difficulties in tampering around the underground facility and low compaction efficiency. Such problems cause deformation and damage to the underground pipes during refilling work and ultimately cause road sinks. Construction methods using CLSM are one of the typical methods to solve these issues, and recently, studies on CLSM using coal ash, which has similar engineering properties as sand, have been actively performed to protect environment and recycle resources. While many studies have been conducted to recycle fly ash in many ways, the demand for recycling bottom ash is increasing as most of the bottom ash is not recycled and reclaimed at ash disposal sites. Therefore, in order to find bottom ash applications using eco-friendly soil binders that are environmentally beneficial and conform with CLSM standards, this study investigated flow characteristics and strength change characteristics of eco-friendly soil binders, weathered granite soil, a typical site-generated soil, bottom ash, and fly ash mixed soil and evaluated the soil pollution to present CLSM application methods using bottom ash.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.185-201
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• 2018

Road lighting is highly preferred as the major nighttime road safety countermeasures. When it comes to the pole-type road lighting, as it's installed at a certain height from the road surface, the driver is dazzled by the light source, interrupting the driver's visibility and furthermore, the light leaks to the area outside the road boundary, worsening the energy efficiency as well as generating the light pollution to the surrounding environment including the animals and plants. The study developed the low-level lighting systems, so it is possible to prevent the lights from being strayed, so there is no any side effects in terms of the sleep deprivation. The study compared the performance as the lightings between low-level lightings and conventional pole based lighting systems. As the results, the low-level lighting systems showed the higher performance in terms of average surface luminance, uniformity, glare compared to the conventional lighting systems.

• Journal of Energy Engineering
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• v.27 no.4
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• pp.64-69
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• 2018

The purpose of this study is to expand the use of coal ash and coal slag in thermal power plants. In addition, controlled low strength materials was developed to prevent mine settlement. Bottom ash and KR slag are mixed at ratio of 7:3 to expand the use of industrial by-products through carbonate reaction and inhibit the exudation of heavy metals. In order to efficiently fill the abandon mine, workability and physical properties were evaluated according to flow. As a result of elution of harmful substance experiment, it was confirmed that the carbonation reaction inhibited the elution of heavy metals. It was confirmed that the difference in water ratio was the difference in specific surface area of the controlled low strength materials. It was confirmed that the working efficiency is excellent when the flowability is 300mm compared to 260mm. compressive strength measurement result was relatively high at 260mm compared to 300mm because the number of pores due to decrease of water ratio was small.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.201-206
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• 2019

Korea is constructing geospatial information application system for geospatial information utilization, but it is trying to establish a system for joint use of geospatial information system centering on Ministry of Land Transport and Transport due to the problem of sharing. The purpose of this study is to investigate and analyze the geospatial information application system operated by local governments, and to suggest the application of geospatial information application system using unmanned aerial images. As a result of the research, it was found that the functions of existing spatial information application system are concentrated on the public services and it is difficult to share and utilize data between administrative departments. In addition, the utilization of the system using unmanned aerial image has been suggested, and additional functions such as vector display, area calculation, and report generation have been derived to improve the usability of geospatial information application system. If additional functions of spatial information application system are added through further studies in the future, it will be possible to use it as a basic data of field survey and policy decision in related fields. And non-experts will be able to improve the efficiency of work by utilizing highly accurate geospatial information in various fields.

• International Area Studies Review
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• v.17 no.4
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• pp.109-130
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• 2013

This study aims to identify the priority for the Gwangyang and Qingdao hinterlands which are in the same category of benchmarking crowed paths. This study has been mainly done with comparison. There is certain limitation to use competitive factors of existing research so, this study has had proper competitive factors deriving from factors analysis and studied hinterland priority of competing factors by AHP. Major results are as follows. First, the factor analysis resulted in 20 factor that were 0.6 or higher loading level of commonality and then these 20 factors were divided into groups: operating factors, service factors, cost factors, port infrastructure factors, and hinterland conditions factors with the rotated component matrix analysis. Second, according to the result of top competitive factors, the best factor was the hinterland condition(0.256). The other factors such as infrastructure, economy, accessibility, incentive, and port traffic in hinterland were highly ranked in terms of general importance using multiple weights. Third, the result of detailed properties importance about the final alternative, Gwangyang hinterland was considered more highly than Qingdao hinterland in the port information system, the support a variety of administrative services, the efficiency of the customs, and the tax benefits.

• International Area Studies Review
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• v.22 no.4
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• pp.145-166
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• 2018

This study is due to global competition, the wall between regions is disappearing, customer needs are diversified, and market and technology are rapidly changing. Future growth engines, the importance of convergence capabilities for industrial competitiveness is being emphasized more. Therefore, companies should seek innovative means to increase the efficiency of the company by establishing optimized global management environment and establishing direction and strategy for utilization of convergence technology by improving industrial competitiveness. Firms must adopt and utilize related new technologies by strengthening their convergence capabilities through dynamic capabilities that are internal resource bases for new product development and process innovation. Globalize markets and technologies can expect higher innovation performance when aligning strategic direction with formalized technology competencies held by the firm and incorporating the convergence capabilities needed for technological innovation into processes. The study focuses on the effects of market and technology orientation on technological innovation performance, whether dynamic and convergence capabilities affect technological innovation performance, and dynamic and convergence capabilities to mediate between market and technology orientation. For the study, we surveyed 51.4% of global and multinational corporations that are internationally active or headquartered overseas. Based on the previous studies, hypotheses were established and the collected data were analyzed through utilization path analysis and Sobel test.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.94-100
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• 2018

Bird electrocution on contact with electricity lines is well reported and is quite common in Mongolian open areas. We visited 15-kV electricity distribution pole lines in a Southern Mongolian semi-desert region three times in 2017, in April, July, and September, to assess their risks to birds. The carcasses of 45 electrocuted birds representing 12 species were identified from 250 poles (overall mortality rate of 1.12% every 10 km). The majority of these electrocuted birds were endangered Saker Falcon (n=11) and common Black Kite (n=11). The lacks of roosting or perching sites in our study sites (indeed other open areas in Mongolia) may resulted for such high rate bird electrocution. A 751-base pair (bp) cytochrome c oxidase I (COI) gene was amplified for DNA sequence-based identification of carcasses that were difficult to identify directly. Our findings revealed the high electrocution risk for birds in Mongolian open areas, especially for the birds of prey, with relatively low-efficiency electrocution mitigation approaches. The findings also indicate that there is a need for better understanding of the risk of bird electrocution, particularly in the open areas. This will contribute to the conservation of endangered species.

• Journal of Korea Technology Innovation Society
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• v.22 no.2
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• pp.207-219
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• 2019

The international trends in activities of government R&D performance measurement is evolving into evidence-based approach to support the verification of objective policy implementation. The European Commission has been implementing KETs (Key Enabling Technologies) policy that incubates nanotech based emerging technologies to support the fourth industrial revolution/revitalization of high-tech manufacturing, and resulting innovations are quantified by KETs Observatory project. The European Commission also built Innovation Radar system that monitors potentially innovative projects within FP7 and Horizon2020 by data analysis. The United States is also upgrading its Federal RePORTER system to quantitatively monitor federal R&D investments with outcomes (including nanotechnology). In the field of Korean nanotechnology, basic statistical data by analyzing NTIS (National Science & Technology Information Service) information is applied in policy field. Developing innovation measurement methodology beyond basic statistical analysis is an international policy issue, and a long-term R&D investment area of a government. The objective of this model study is to quantify the innovation potential of nano R&D investments conducted by Korea government, using input-output based efficiency measurement model and NTIS (National Science & Technology Information Service) that is comprehensive data portal for national R&D investments/outcomes including nanotechnology.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.219-224
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• 2019

Purpose: The image registration of radiographic image and digital surface data is essential in the computer-guided implant guide system. The purpose of this study was to examine the effects of using micro-screw on the working time and convenience of operators in the process of image matching for guided implant surgery. Materials and methods: A mandibular dental model was prepared in partial edentulism for Kennedy class I classification. Two micro-screws were placed on the each side of retromolar area. Radiographic and scan images were taken using computed-tomography and digital scanning. The images were superimposed by 12 operators in software in two different conditions: using remaining teeth image alone and using teeth and micro-screws images. Working time, operator convenience and satisfaction were obtained, and analyzed using the Mann-Whitney U test (${\alpha}=.05$). Results: The working time was not statistically different between image registration conditions (P>.05); however, operator convenience and satisfaction were higher in the teeth and micro-screw assisted condition than in the teeth-alone assisted condition (P<.001). Conclusion: The use of micro-screw for the image registration has no effect in working time reduction, but improves operator convenience and satisfaction.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.