• Korean Journal of Remote Sensing
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• v.37 no.6_3
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• pp.2035-2046
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• 2021

Glacier movement speed is the most basic measurement for glacial dynamics research and is a very important indicator in predicting sea level rise due to climate change. In this study, the two-dimensional velocity measurements of Campbell Glacier located in Terra Nova Bay in East Antarctica were observed through the SAR offset tracking technique. For this purpose, domestic KOMPSAT-5 SAR satellite images taken on July 9, 2021 and August 6, 2021 were acquired. The Multi-kernel SAR offset tracking proposed through previous studies is a technique to obtain the optimal result that satisfies both resolution and precision. However, since offset tracking is repeatedly performed according to the size of the kernel, intensive computational power and time are required. Therefore, in this study, we strategically proposed a coarse-to-fine offset tracking approach. Through coarse-to-fine SAR offset tracking, it is possible to obtain a result with improved observation precision (especially, about 4 times in azimuth direction) while maintaining resolution compared to general offset tracking results. Using this proposed technique, a two-dimensional velocity measurements of Campbell Glacier were generated. As a result of analyzing the two-dimensional movement velocity image, it was observed that the grounding line of Campbell Glacier exists at approximately latitude -74.56N. The flow velocity of Campbell Glacier Tongue analyzed in this study (185-237 m/yr) increased compared to that of 1988-1989 (140-240 m/yr). And compared to the flow velocity (181-268 m/yr) in 2010-2012, the movement speed near the ground line was similar, but it was confirmed that the movement speed at the end of the Campbell Glacier Tongue decreased. However, there is a possibility that this is an error that occurs because the study result of this study is an annual rate of glacier movement that occurred for 28 days. For accurate comparison, it will be necessary to expand the data in time series and accurately calculate the annual rate. Through this study, the two-dimensional velocity measurements of the glacier were observed for the first time using the KOMPSAT-5 satellite image, a domestic X-band SAR satellite. It was confirmed that the coarse-to-fine SAR offset tracking approach of the KOMPSAT-5 SAR image is very useful for observing the two-dimensional velocity of glacier movements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.294-304
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• 2019

Abstract Greenhouse Gas (GHG) emissions from agriculture and forestry sources in the energy sector have been estimated based on a top-down approach, which is an efficient way to estimate GHG emissions with the limited number of emission factors and activity data. On the other hand, for GHG abatement policies, more detailed information and data on GHG emissions are required. This study discusses how to improve the estimates of GHG emissions from the agricultural and forestry sources in the energy sector. To this end, this paper reviews the current estimation method of GHG emissions and presents three suggestions to enhance the current method. First, the development of country specific emission factors and corresponding activity data is proposed based on the 2006 IPCC Guidelines, National Greenhouse Gas Inventory Reports from other countries, and Domestic Statistics. Second, the uncertainty in CO₂ emissions from agriculture in energy sector based on 2006 IPCC Guidelines is estimated, and ways of reducing the uncertainty in CO₂ emissions are suggested. Finally, a potential way to reflect the GHG emissions from the use of renewable energy is suggested.

• Journal of Broadcast Engineering
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• v.11 no.2 s.31
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• pp.207-221
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• 2006

A fully automatic and computationally efficient method is proposed for intelligent display of soccer video on small multimedia mobile devices. The rapid progress of the multimedia signal processing has contributed to the extensive use of multimedia devices with a small LCD panel. With these emerging small mobile devices, the video sequences captured for standard- or HDTV broadcasting may give the small-display-viewers uncomfortable experiences in understanding what is happening in a scene. For instance, in a soccer video sequence taken by a long-shot camera technique, the tiny objects (e.g., soccer ball and players) may not be clearly viewed on the small LCD panel. Thus, an intelligent display technique is needed for small-display-viewers. To this end, one of the key technologies is to determine region of interest (ROI), which is a part of the scene that viewers pay more attention to than other regions. In this paper, the focus is on soccer video display for mobile devices. Instead of taking visual saliency into account, we take domain-specific approach to exploit the characteristics of the soccer video. The proposed scheme includes three modules; ground color learning, shot classification, and ROI determination. The experimental results show the propose scheme is capable of intelligent video display on mobile devices.

• Journal of Korea Water Resources Association
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• v.53 no.5
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• pp.323-336
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• 2020

Owing to climate change, the annual precipitation in Korea has increased since the 20th century, and it is projected to continue increasing in the future. This trend of increasing precipitation will raise the possibility of floods; hence, it is necessary to establish national adaptation plans for floods, based on a reasonable flood risk assessment. Therefore, this study focuses on developing a framework that can assess the flood risk across the country, as well as computing the flood risk index (FRI). The framework, which is based on IPCC AR5, is established as a combination of three indicators: hazard, exposure, and capacity. A data-based approach was used, and the weights of each component were assigned to improve the validity of the FRI. A Spearman correlation analysis between the FRI and flood damage verified that the index was capable of assessing potential flood damage. When predicting scenarios for future assessment using the HadGEM3-RA based on RCP 4.5 and 8.5, the flood risk tends to be lower in the early and mid-21st century, and it becomes higher at the end of the 21st century as compared with the present.

• Journal of Korea Water Resources Association
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• v.49 no.5
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• pp.361-372
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• 2016

Reliable long-term dam inflow prediction is necessary for efficient multi-purpose dam operation in changing climate. Since 2000s the teleconnection between global climate indices (e.g., ENSO) and local hydroclimate regimes have been widely recognized throughout the world. To date many hydrologists focus on predicting future hydrologic conditions using lag teleconnection between streamflow and climate indices. This study investigated the utility of teleconneciton for predicting dam inflow with 1-month lead time at Andong dam basin. To this end 40 global climate indices from NOAA were employed to identify potential predictors of dam inflow, areal averaged precipitation, temperature of Andong dam basin. This study compared three different approaches; 1) dam inflow prediction using SWAT model based on teleconneciton-based precipitation and temperature forecast (SWAT-Forecasted), 2) dam inflow prediction using teleconneciton between dam inflow and climate indices (CIR-Forecasted), and 3) dam inflow prediction based on the rank of current observation in the historical dam inflow (Rank-Observed). Our results demonstrated that CIR-Forecasted showed better predictability than the other approaches, except in December. This is because uncertainties attributed to temporal downscaling from monthly to daily for precipitation and temperature forecasts and hydrologic modeling using SWAT can be ignored from dam inflow forecast through CIR-Forecasted approach. This study indicates that 1-month lead dam inflow forecast based on teleconneciton could provide useful information on Andong dam operation.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.101-108
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• 2015

This paper presents the implementation of a system that recommends empirical best routes based on classification of large trajectory data. As many location-based services are used, we expect the amount of location and trajectory data to become big data. Then, we believe we can extract the best empirical routes from the large trajectory repositories. Large trajectory data is clustered into similar route groups using Hadoop MapReduce framework. Clustered route groups are stored and managed by a DBMS, and thus it supports rapid response to the end-users' request. We aim to find the best routes based on collected real data, not the ideal shortest path on maps. We have implemented 1) an Android application that collects trajectories from users, 2) Apache Hadoop MapReduce program that can cluster large trajectory data, 3) a service application to query start-destination from a web server and to display the recommended routes on mobile phones. We validated our approach using real data we collected for five days and have compared the results with commercial navigation systems. Experimental results show that the empirical best route is better than routes recommended by commercial navigation systems.

• Journal of Life Science
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• v.23 no.8
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• pp.998-1003
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• 2013

The effects of oral administration of estradiol-$17{\beta}$ (E2) on glass eels (Body weight: $0.16{\pm}0.05g$, Total length: $6.2{\pm}0.9cm$) and young eels (Body weight: $2.6{\pm}0.6g$, Total length: $13.2{\pm}0.6cm$) on gonadal sex and growth were examined, respectively. Glass eels were fed a diet containing E2 at a dose of 10 mg/kg or 25 mg/kg, respectively, for five months. The female ratio significantly increased in all E2-treated groups (10 mg/kg diet group: 70%; 25 mg/kg diet group: 90%) when compared to the control group (10%). Young eels were fed a diet containing E2 at a dose of 25 mg/kg for four months. The female ratio also significantly increased in the E2-treated groups (60%) compared to the control group (20%). The highest female ratio was observed in the stage of glass eels rather than young eels. In all experiments, however, the growth of eels treated with E2 was similar to that of controls to the end of the experiment. Thus, oral administration of E2 could be a good approach to controlling sex differentiation.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.563-572
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• 2004

Since bacterial plaque is known as the major cause of every oral disease, it is necessary to control plaque to maintain periodontal health. Although tooth brushing has been the typical method of plaque control, additional use of plaque control devices are necessary for cleansing interdental areas. Dental floss has been used for a long time as the additional plaque control device and proved to be effective. The newly developed embossed new dental pick is composed of elastic plastic material in form with its tip longer than other toothpick. In addition, as thickness of the tip gradually increases, it can be adapted easily with minimal trauma to interdental gingiva. The embossed tip can remove dental plaque easily, and the opposite end can approach lingual and palatal areas through triple angulation. Therefore, the authors studied the effect of embossed new dental pick and dental floss on periodontally involved 15 patient. The following results were obtained. 1. For embossed new dental pick, probing depth at baseline, 1 week, 4 weeks were $3.6{\pm}0.6mm$, $3.4{\pm}0.5mm$, $3.2{\pm}0.5mm$, respectively, and $4.2{\pm}0.9mm$, $4.1{\pm}0.9mm$, $4.0{\pm}0.9mm$, respectivly for clinical attachment level. 2. In case of embossed new dental pick, bleeding on probing at baseline, 1 week, 4 weeks were $43.0{\pm}4.4%$, $28.5{\pm}5.1%$, $22.2{\pm}5.6%$, respectively, and, at 1 week and 4 weeks, they were significantly different from that of dental floss. 3. Gingival index of toαhpick at baseline, 1 week, 4 weeks were $1.7{\pm}0.5$, $1.0{\pm}0.3$, $0.9{\pm}0.2$, respectively, and, $1.7{\pm}0.5$, $1.1{\pm}0.4$, $1.0{\pm}0.4$, respectively for plaque index, and $3.0{\pm}0.5$, $1.7{\pm}0.5$, $1.4{\pm}0.4$, respectively for proximal plaque index. proximal plaque index at 4 weeks was significantly different from that of dental floss. 4. The result of questionnaire showed that the two types of device were both satisfactory, however, embossed new dental pick had higher preference as well as satisfaction. As a result, embossed new dental pick is thought to be clinically effective for its simplicity and good accessibility.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.4
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• pp.329-334
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• 2017

The structures, which are made up with the huge number of degrees-of-freedom and the assembly of substructures, have a great complexity. In order to increase the computational efficiency, the analysis models have to be simplified. Many substructuring techniques have been developed to simplify large-scale engineering problems. The techniques are very powerful for solving nonlinear problems which require many iterative calculations. In this paper, a modal derivatives-based model order reduction method, which is able to capture the stretching-bending coupling behavior in geometrically nonlinear systems, is adopted and investigated for its performance evaluation. The quadratic terms in nonlinear beam theory, such as Green-Lagrange strains, can be explained by the modal derivatives. They can be obtained by taking the modal directional derivatives of eigenmodes and form the second order terms of modal reduction basis. The method proposed is then applied to a co-rotational finite element formulation that is well-suited for geometrically nonlinear problems. Numerical results reveal that the end-shortening effect is very important, in which a conventional modal reduction method does not work unless the full model is used. It is demonstrated that the modal derivative approach yields the best compromised result and is very promising for substructuring large-scale geometrically nonlinear problems.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.53-58
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• 2020

Many stars are delivering various contents such as real time talks through Internet personal broadcasting to communicate with fans. For stars and entertainment companies that expect the effect of communicating with fans through Internet broadcasting, it can be said that it is important to grasp viewers' viewing motivation and satisfaction. Thus, we analyzed the viewing motivation and satisfaction of Chinese viewers' Internet personal broadcasting of famous celebrities based on the uses and gratifications approach. To this end, an online survey was conducted, and as a result, 'emotional motivation' and 'functional motivation' were found as Chinese viewers' motivation for viewing Internet personal broadcasting of famous celebrities. In addition, it was found that viewers' satisfaction increased as the viewers' 'emotional viewing motivation' increased. From the results of this study, it seems that a strategy of subdividing programs by reflecting the audience characteristics such as age and occupation is needed. It can be a way to expand the number of viewers and the intended broadcasting effect by designing and producing programs for personalized celebrity internet broadcasting by segmenting audiences.