• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.45-51
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• 2021

In accordance with the rapid non-face-to-face environment and mobile first strategy, the explosive increase and creation of many structured/unstructured data every year demands new decision making and services using big data in all fields. However, there have been few reference cases of using the Hadoop Ecosystem, which uses the rapidly increasing big data every year to collect and load big data into a standard platform that can be applied in a practical environment, and then store and process well-established big data in a relational database. Therefore, in this study, after collecting unstructured data searched by keywords from social network services based on Hadoop 2.0 through three virtual machine servers in the Spring Framework environment, the collected unstructured data is loaded into Hadoop Distributed File System and HBase based on the loaded unstructured data, it was designed and implemented to store standardized big data in a relational database using a morpheme analyzer. In the future, research on clustering and classification and analysis using machine learning using Hive or Mahout for deep data analysis should be continued.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.43-48
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• 2018

An etchant capable of forming a circuit in an FTO film that can replace ITO, which depends on full imports, was prepared. The etching solution is composed of 1 to 30% by weight of fluoride, 1 to 20% by weight of acid, 0.5 to 5% by weight of surfactant, 5 to 20% by weight of solvent, 0.5 to 10% by weight of corrosion inhibitor and the balance of water. This etchant can be etched using a dry film, thereby reducing the cost, and is free from bubbles and residue of the etchant. The characteristics of the etchant were etched in a time of 2 minute with a 100 nm thick FTO, and the etchant temperature was maintained at $50^{\circ}C$. An undercut of -0.00364% was obtained when put into a 2 minute etching solution. No harmful substances such as Cd, Pb, Hg and Cr components were measured. The use of FTO in Korea where rare earths do not exist can achieve localization and import substitution effect.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.17-23
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• 2019

IaaS is well known as a very cost effective computing service which enables required infrastructures to be rented on demand without ownership of real hardwares. It is very suitable for price sensitive services due to pay-per-use style. Operators of such services would want to adjust utilization policy quickly by estimating costs for cloud infrastructures as soon as possible. However, swift response is not possible due to that cloud service providers provide a dozen or so hours delayed billing information. Our work proposes a realtime IaaS cost estimation model based on usages monitored by virtual machine instance. We operate PC laboratory service on a public cloud during full semester to validate our suggested model. From that experiment, an averaged disparity between estimation and actual cost is less than 5.2%.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.129-135
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• 2019

Recently, it is anticipated that 5G network would play the significant role of the neural network for 4th generation industry revolution and create huge value for the new market. However, in spite of proliferating prospect of 5G network industry and leading position in the launch of 5G, network operators have hesitated to give their full support to establishing proper network. Due to the lack of business models promoting 5G industry, network operators feel that they will not realize the return from the exorbitant investment in 5G network establishment. Moreover, the rigorous research efforts to investigate and analyze the various business environments regarding 5G rarely exists. Therefore, the purpose of the research is to holistically propose the research issues related to the technology, service providing method, governmental policy, and business models in commercializing and promoting 5G network.

• Electronics and Telecommunications Trends
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• v.34 no.1
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• pp.75-85
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• 2019

Quantum technology is undergoing a revolution. Theoretically, strange phenomena of quantum mechanics, such as superposition and entanglement, can enable high-performance computing, unconditionally secure communication, and high-precision sensing. Such theoretical possibilities have been examined in the last few decades. The goal now is to apply these quantum advantages to daily life. Europe, where quantum mechanics was born a 100 years ago, is struggling to be placed at the front of this quantum revolution. Thus, the European Commission has decided to invest 1 billion EUR over 10 years and has initiated the ramp-up phase with 20 projects in the fields of communication, simulation, sensing and metrology, computing, and fundamental science. This program, approved by the European Commission, is called the "Quantum Technology Flagship" program. Its first objective is to consolidate and expand European scientific leadership and excellence in quantum research. Its second objective is to kick-start a competitive European industry in quantum technology and develop future global industrial leaders. Its final objective is to make Europe a dynamic and attractive region for innovative and collaborative research and business in quantum technology. This program also trains next-generation quantum engineers to achieve a world-leading position in quantum technology. However, the most important principle of this program is to realize quantum technology and introduce it to the market. To this end, the program emphasizes that academic institutes and industries in Europe have to collaborate to research and develop quantum technology. They believe that without commercialization, no technology can be developed to its full potential. In this study, we review the strategy of the Quantum Europe Flagship program and the 20 projects of the ramp-up phase.

• Korean Journal of Community Nutrition
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• v.24 no.2
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• pp.117-126
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• 2019

Objectives: This study was conducted to investigate the current difficulties surrounding children's obesity management and evaluate the application of a mobile phone as a tool to overcome such difficulties of obesity management from the perspective of main caregivers of elementary school students. Methods: The qualitative data were collected through 3 focus group interviews including 6 full-time housewives, 7 mothers with overweight children, and 4 working mothers. Data were analyzed using a thematic approach. Results: The limitations of current children's obesity management included difficulty in diet management and exercise as well as challenges of setting goals and lack of support at the household and school levels. Mobile technology may be useful to overcome the current problems by providing real-time knowledge on diet management and physical activity, online compensation scheme according to goal setting, and interactive environmental supports at both household and school levels for promoting overall health. Conclusions: The mobile-based multiple support program may assist in overcoming the current limitations of child obesity management by providing tailored information and by creating a more supportive environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.2
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• pp.87-96
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• 2019

Low power issue is one of the most critical problems in the Internet of Things (IoT), which are powered by battery. To solve this problem, various approaches have been presented so far. In this paper, we propose a method to reduce the power consumption by reducing the numbers of accesses into the flash memory consuming a large amount of power for on-chip software execution. Our approach is based on using cooperative logging structure to distribute the sampling overhead in single sensor node to adjacent nodes in case of rare-event applications. The proposed algorithm to identify event occurrence is newly introduced with negative feedback method by observing difference between past data and recent data coming from the sensor. When an event with need of flash access is determined, the proposed approach only allows access to write the sampled data in flash memory. The proposed event detection algorithm (EDA) result in 30% reduction of power consumption compared to the conventional flash write scheme for all cases of event. The sampled data from the sensor is first traced into the random access memory (RAM), and write access to the flash memory is delayed until the page buffer of the on-chip flash memory controller in the micro controller unit (MCU) is full of the numbers of the traced data, thereby reducing the frequency of accessing flash memory. This technique additionally reduces power consumption by 40% compared to flash-write all data. By sharing the sampling information via LoRa channel, the overhead in sampling data is distributed, to reduce the sampling load on each node, so that the 66% reduction of total power consumption is achieved in several IoT edge nodes by removing the sampling operation of duplicated data.

• Korean Journal of Acupuncture
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• v.35 no.4
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• pp.159-165
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• 2018

Objectives : This study was performed to review the efficacy of national and international randomized controlled trials (RCTs) investigating evidence on thread embedding therapy for knee osteoarthritis. Methods : Online databases (PubMed, EMBASE, Cochrane, NDSL, OASIS, CNKI) were searched for studies where thread embedding therapy was performed for Knee Osteoarthritis from their inception to July 2018. Two researchers independently performed the search. Only RCTs were selected. Eligible studies were selected first by the abstract and the title and then included after full-texts were read. Risk of bias of the included studies were evaluated using the Cochrane risk of bias assessment tool. Data were narratively summarized. Results : There were 334 studies retrieved from the databases, resulting in analysis of 3 RCTs. There was an average of 1.5 treatment visits over a 7 day period and evaluation tool used was efficacy rate, with traditional acupuncture being the most common control used in the trials. Statistically significant improvement by thread embedding therapy was reported. None of the included RCTs reported on adverse reactions. The risk of bias of the included studies was generally unclear. Conclusion : The review suggests that thread embedding therapy can be effective in knee osteoarthritis. But there was a lack of detailed information about the treatment procedures, and the risk of bias was unclear. Therefore, there is insufficient evidence for thread embedding therapy for knee osteoarthritis.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.187-192
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• 2018

This thesis is about the study of inverter terminal boxes in a explosion proof type exhaust fan that can control wind volume and operating time. In Korea, there is no ventilator to adjust the amount of wind and operating time when working in poor conditions. The purpose of the project is to create a explosion terminal box that can control the operating time and wind speed of a suitable explosion ventilator in hazardous environments. The two explosion-proof switches allow the operation time to be driven 1 hour, 3 hours and continuous time, and the speed of the induction motor rotation was set in 3 stages at 2000 rpm, 2600 rpm and 3000 rpm to control the volume. The tested motor used a half-horsepower barrier three-phase induction motor and a full-bridge inverter to set the desired flow rate and operating time.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.280-287
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• 2019

In the oral cavity, the teeth undergo wear and corrosion throughout their lives. Progressive and constant tooth wear is a natural phenomenon of aging, but wear and corrosion due to specific factors are pathological factors. It can cause pathological damage of the occlusal surface, aesthetic problems, dimensional loss and jaw joint disorders. This case is a 26-year-old female patient with general tooth abrasion and erosion on the entire dentition. Diagnostic wax-up was fabricated based on the information including digital facial analysis, physiological stabilization, and evaluation of anterior crown length. Through the digital analysis, the necessary guides for crown lengthening were prepared and the mastication function and esthetics were evaluated by using temporary crowns. Definitive prosthesis was fabricated with the zirconia restorations. The results were satisfactory when they were observed 3 months of follow-up.