• Polymer(Korea)
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• v.35 no.6
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• pp.599-604
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• 2011

The PET-PEN copolymers have been synthesized and the effect of their morphology on the physical properties of polyester flexible substrate was investigated. It was found that the block sequence of synthesized copolymer was varied depending upon DMT/NDC ratio in polymerization. Higher PET-PEN and PEN block sequence in polyester copolymer resulted in the increase of glass transition temperature and it caused the enhancement of dimensional stability as a polyester flexible substrate. The highest coefficient of thermal expansion(CTE) was obtained when DMT/NDC ratio is 50/50. Synthesized PET-PEN copolymer seems to be acceptable as a flexible substrate since it shows that their optical transmittance at 550 nm is over 80% and thermal weight loss at $280^{\circ}C$ for 1 hr is less than 0.4 wt%.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.693-703
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• 2019

Long-term coastal topographical data is critical for analyzing temporal and spatial changes in shorelines. Especially understanding the change trends is essential for future coastal management. For this research, in the data preparation, we obtained digital aerial images, terrestrial laser scanning data and UAV images in the year of 2009. 2018 and 2019 respectively. Also tidal observation data obtained by the Korea Hydrographic and Oceanographic Agency were used for Bangamoeri beach located in Ansan, Gyeonggi-do. In the process of it, we applied the photogrammetric technique to extract the coastline of 4.40 m from the stereo images of 2009 by stereoscopic viewing. In 2018, digital elevation model was generated by using the raw data obtained from the laser scanner and the corresponding shoreline was semi-automatically extracted. In 2019, a digital elevation model was generated from the drone images to extract the coastline. Finally the change rate of shorelines was calculated using Digital Shoreline Analysis System. Also qualitative analysis was presented.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.217-223
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• 2019

The relationship between balance and ankle muscle characteristics (strength and flexibility) may be important to identify those at an increased risk of falling and to develop fall-prevention training programs. The association between ankle muscle characteristics (strength and flexibility) and balance has not previously been studied. The purpose of this study assessed the relationship between ankle muscle characteristics and balance. Sixteen healthy participants volunteered to participate in the study. Dynamic balance measured using Y-balance kit. Ankle muscle characteristics (strength and flexibility) measured using hand-held dynamometer and goniometry. The results indicated a positive correlation between ankle invertor muscle strength and Y-balance test performance. Clinicians should consider ankle muscle strength during therapeutic interventions to improve dynamic balance.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.391-403
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• 2021

This study was studied to analyze the current early childhood education system based on elements of education publicness and to explore policy tasks for developing early childhood education policies. Qualitative literature analysis was conducted by collecting official government documents and reports from national research institutes, and the publicity level of early childhood education was evaluated based on the elements of publicity. As a result of the study, Korea's early childhood education policy has been promoted in the direction of strengthening the public nature of early childhood education, such as the introduction of the Nuri course. Quantitative expansion of public nature has been achieved, but now it is necessary to re-establish the policy direction focusing on the qualitative reinforcement of public nature and to supplement the system. This study suggests a direction for a review of early childhood education in general.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.105-113
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• 2019

The purpose of this study is to analyze cyber security risk modeling of critical infrastructure, draw out limitations and improvement measures. This paper analyzed cyber security risk modeling of national critical infrastructure like as electricity sector, nuclear power plant, SCADA. This paper analyzed the 26 precedent research cases of risk modeling in electricity sector, nuclear power plant, SCADA. The latest Critical Infrastructure is digitalized and has a windows operating system. Critical Infrastructure should be operated at all times, it is not possible to patch a vulnerability even though find vulnerability. This paper suggest the advanced cyber security modeling characteristic during the life cycle of the critical infrastructure and can be prevented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.83-90
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• 2019

Recently, the need to prevent or treat cognitive impairment in older adults has been arising. In particular, they tried to diagnose MCI as an early stage of Alzheimer's disease and to delay the progression to dementia through training cognitive function. Most of cognitive function training have been manufactured to game contents which related to several cognitive function, and it needs to be verified quantitatively whether subjects are paying attention to cognitive function training. Thus in this study, we measured and analyzed EEG signals while performing attention training game contents. As an analysis method, we utilized CI, which shows how much they are focusing on, and RI, which shows how stable they are. The result of this study can be seen that all the subjects' CI were increased, which means that the subjects performed game contents with concentration.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.259-268
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• 2018

The purpose of this study is to propose a training method customized to the level of cognitive abilities to increase users' interest and engagement while using cognitive function training contents. The level of cognitive ability of the users was based on the clustering based on the users' information and Mini-Mental Statue Examination-Korea Child test score using the K-means algorithm applied collaborative filtering. The results were applied to the integrated cognitive function training system, and the contents order and difficulty level of the cognitive function training area were recommended to the user's cognitive ability level. Particularly, the contents difficulty control was designed to give a high immersion feeling by applying the 'flow theory' method that users can repeatedly feel tension and comfort. In conclusion, the user-customized cognitive function training method proposed in this paper can be expected to be more effective and rehabilitative results than existing therapists' subjective setting of contents order and difficulty level.

• International Area Studies Review
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• v.14 no.1
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• pp.77-97
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• 2010

Recently, countries on the Caspian Sea were had heavily interested due to instability of international resource market. These countries having been developed basing on energy exports, especially Kazakhstan have drastically grown during a decades. However economy, heavily relied on the exports of energy, is influenced on fluctuation in the international energy price as well as sometimes exposed at Dutch disease. These days, Kazakhstan, increased trade and investment with Korea, has been on the rise as new supplier for energy. Therefore, economic change in Kazakhstan can be an important issue. In this paper, we analyze relations among oil price, interest rate, and real exchange rate during sample period from January 1999 to December 2008 expanding Balasa-Samuelson model. Empirical results present that oil price, interest rate, and real exchange rate mutually keep their balance. Eventually, we find out Kazakhstan has exposed at Dutch disease since oil price and interest rate have negative impacts on real exchange rate respectively.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.826-831
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• 2018

This study presents fabrication of bi-compartmental particles labeled by multiple fluorescence. To compartmentalize fluorescent expression at the particle, two fluorescent dyes with less overlap of the excitation and emission spectra are selected. To ensure the fluorescence stability, the fluorescent dyes contain acrylate functional groups in the molecules so that they can be cross-linked together with monomers constituting the particle. Strong fluorescent expression and compartmentalization were observed at the particle fabricated using the selected fluorescent dyes through confocal microscopy. Furthermore, long-term fluorescence stability was verified by measuring fluorescent expression and intensity for 4 weeks. We anticipate that the bi-compartmental particles labeled by multiple fluorescence can be widely used for multi-target drug delivery system, analysis of 3 dimensional Brownian motion, and investigation of 3 dimensional complex self-assembled morphologies.

• Journal of Practical Engineering Education
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• v.11 no.1
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• pp.43-50
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• 2019

A specific example of how to practical engineering education was conducted through the results of the formation of an insomniac mitigation system using aromatic substance and lighting that were conducted over three semesters of a series of curricula related to the composition of graduation works and graduation thesis writing in electronic engineering majors is given as a criteria conditions to certify graduation. Propose the systematic process of the learning achievement process, having learned how to solve problems and to communicate on a team basis. In addition, is analyzed the results of the achievement satisfaction in the major courses conducted with the acquisition of knowledge in engineering, and confirmed that it was included in the level descriptor of engineering issues on the results of the performance measurement and learning in the curriculum.