• Journal of the Korean earth science society
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• v.42 no.4
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• pp.445-458
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• 2021

Gravity Recovery and Climate Experiment (GRACE) gravimeter satellites observed the Earth gravity field with unprecedented accuracy since 2002. After the termination of GRACE mission, GRACE Follow-on (GFO) satellites successively observe global gravity field, but there is missing period between GRACE and GFO about one year. Many previous studies estimated terrestrial water storage (TWS) changes using hydrological models, vertical displacements from global navigation satellite system observations, altimetry, and satellite laser ranging for a continuity of GRACE and GFO data. Recently, in order to predict TWS changes, various machine learning methods are developed such as artificial neural network and multi-linear regression. Previous studies used hydrological and climate data simultaneously as input data of the learning process. Further, they excluded linear trends in input data and GRACE/GFO data because the trend components obtained from GRACE/GFO data were assumed to be the same for other periods. However, hydrological models include high uncertainties, and observational period of GRACE/GFO is not long enough to estimate reliable TWS trends. In this study, we used convolutional neural networks (CNN) method incorporating only climate data set (temperature, evaporation, and precipitation) to predict TWS variations in the missing period of GRACE/GFO. We also make CNN model learn the linear trend of GRACE/GFO data. In most river basins considered in this study, our CNN model successfully predicts seasonal and long-term variations of TWS change.

• 발명특허
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• v.28 no.9 s.327
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• pp.64-69
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• 2003

• Korea Trade Review
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• v.47 no.5
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• pp.59-74
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• 2022

The exemption clause of recurring shipments refers to the insurer's exemption in Short-term Export Credit Insurance for the additional shipment which was shipped on board while any foregoing shipment was unpaid beyond its due date over 30 days. The recurring shipments are constituted with two factors: the due date of the foregoing shipment and the shipment date of the additional export. The exemption clause of recurring shipments has been eased by extending the grace period for payment up to 60 days from 30 days for the transactions between exporters and importers having the history of payments which were made customarily in delay. This research argues that the current grace period is for the buyers who customarily delay their payments, and that the insurer introduce a grace period for shipment in favor of exporters for the additional shipment which was delayed in on-boarding due to reasons beyond the control of exporters. In consideration of the waiting time and the on-boarding time at ports for container freight, shipments are frequently delayed, which entails those shipments to be indemnified by the exemption clause of recurring shipments. Roll-overs and Blank Sailings also cause the container freight to be delayed in on-boarding. This research is expected to contribute to further development of Short-term Export Credit Insurance in K-SURE.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.5
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• pp.513-518
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• 2008

The research of global-scale mass redistribution and it changed by Earth gravity filed variation observations, including Earth's oblateness $J_2$(also called low degree spherical harmonic coefficient $C_{20}$), is in continuous progress. Recently, the comparative analysis of geodetic observation SLR can be made by the development of GRACE and other time-variable gravity measurements. In this study, $C_{20}$ time series changes in the value of comparative analysis was got by GRACE monthly Gravity filed model (CSR RL04) for the period April 2002 to May 2008. And comparative analysis the harmonic coefficients of $C_{20}$ was obtained from SLR observations. Signal analysis for two time-series data was made by wavelet transform, CWT(continuous wavelet transform), XWT(cross wavelet transform) and WTC(wavelet coherence) methods. The results indicate that GRACE and SLR values for $C_{20}$ had both decreasing trend, as well as SLR data represent the annual frequencies, and GRACE was semiannual variations. In addition, the results of GRACE and SLR had a strong correlation with the XWT and WTC in an annual cycle.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.265-277
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• 2019

Changes in the amount, intensity, frequency, and type of precipitation, in conjunction with global warming and climate change, critically impact groundwater recharge and associated groundwater level fluctuations. Monthly gravity levels by the Gravity Recovery and Climate Experiment (GRACE) are acquired to monitor total water storage changes at regional and global scales. However, there are inherent difficulties in quantitatively relating the GRACE observations to groundwater level data due to the difficulties in spatially representing groundwater levels. Here three local interpolation methods (kriging, inverse distance weighted, and natural neighbor) were implemented to estimate the areal distribution of groundwater recharge changes in South Korea during the 2002-2016 period. The interpolated monthly groundwater recharge changes are compared with the GRACE-derived groundwater storage changes. There is a weak decrease in the groundwater recharge changes over time in both the GRACE observations and groundwater measurements, with the rate of groundwater recharge change exhibiting mean and median values of -0.01 and -0.02 cm/month, respectively.

• Journal of the Korean earth science society
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• v.39 no.5
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• pp.473-482
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• 2018

During the period of 2002 to 2017, the Gravity Recovery And Climate Experiment (GRACE) had observed time-varying gravity changes with unprecedented accuracy. The GRACE science data centers provide the monthly gravity solutions after removing the sub-monthly mass fluctuation using geophysical models. However, model misfit makes the solutions to be contaminated by aliasing errors, which exhibits peculiar north-south stripes. Two conventional filters are used to reduce the errors, but signals with similar spatial patterns to the errors are also removed during the filtering procedure. This would be particularly problematic for estimating the ice mass changes in Western Antarctic Ice Sheet (WAIS) and Antarctic Peninsula (AP) due to their similar spatial pattern to the elongated north-south direction. In this study, we introduce an alternative filter to remove aliasing errors using the Empirical Orthogonal Functions (EOF) analysis. EOF can decompose data into different modes, and thus is useful to separate signals from noise. Therefore, the aliasing errors are effectively suppressed through EOF method. In particular, the month-to-month mass changes in WAIS and AP, which have been significantly contaminated by aliasing errors, can be recovered using EOF method.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.2
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• pp.357-379
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• 2010

The citation analysis is not applied to group measurements but to individual papers finding their impact factors among citation chains which are created by tracing citing-cited relationship between any two papers in data set. The individual impact factor is measured by adding each value derived from citation chain. Each paper's impact factor index is calculated by adding the values of each index by direct citing-cited relationship, and the values of each impact factor made by indirectly influencing to the papers in the citation chain. The research introduces a grace period, in which the system holds the papers not cited by other papers yet, but are expected to be cited within this period. Eventually not cited papers after the grace period would be eliminated by the system. The experiment suggests a reasonable database in which the highly influenced papers are gathered, and could be serviced in stead of buying databases filled with worthless not-cited-papers.

• Journal of the Korean Society of Costume
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• v.23
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• pp.197-209
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• 1994

The purpose of this study is to present a way to analyze and review the subjective view of the aesthetic for dress based on the framework of the aesthetic categories suggested by aesthetics. In order to define objectivism and subjectivism of the aesthetic of dress, theoretical studies on the aesthetic categories of dress were precded. And empirical studies on the aethetic categories of dress for selected period, the Renaissance (16th century) and the Baroque(17 th century). The results were follows : The objectivism of the aesthetic is the point of that an object causes human to feel and judge aesthetically, that is that of dress means judge aesthetically, that is that of dress means formal characteristic of dress and pervasive ideology expressed in dress. the subjectivism of the aesthetic is the point that the aesthetic is ruted in human, that is that of dress has been studied in relation to the image, the aesthetic consciousness m, or the aesthetic categories of dress. Especially, the aesthetic category is one of the universal and valid methods for the analysis of subjectivism of the aesthetic for dress. This study includes beauty, grace, elegance , the sublime, the tragic , the comic, aptness, ugliness as aesthetic categories of dress . Beauty is perfection and rule. Grace pleases human by sense. Elegance comes from the harmony of sense and spirit. the sublime comes into existence that human feels pleasure as well as displeasure simultaneously when human is overehelmed by objects. The tragic is the sense of the present of something valuable even if there is suffering. The comic is the sense of the presence of something amusing even if there is displeasure caused by contradiction. Apteness means utility in terms of the objectivism and , formality in terms of the subejctivism. Ugliness is opposite to beauty. As the result of emperical studies, the aesthetic categories of the Renaissance dress showed harmonious, balanced, and symmetrical beauty, and the magnificent, and enlarged sublime. In addition to these , grace and elegance were also found to some extent. Aesthetic categories of the Baroque dress show feminie, soft, cheerful, and fantastic grace, asymmetric , disarmonious, and extraordinary uglinesss, and the magnificient , grave, and dignified sublime.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.8
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• pp.1233-1243
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• 2008

This study examined return policies of the Korean retailers and their differences by retail format. Return policies of 363 retailers including dept stores, discount stores, brand consignment stores, small shops, outlet stores, TV home shopping companies, and internet shopping malls were collected. Acceptance of refund or/and exchange, return grace period, and return requirements or restrictions of each retailer were analyzed. The results showed that most retail formats except small shops and internet shopping malls allowed refund. The seven day return grace period was most common though large retail chains allowed more generous time frames and small shops allowed shorter dates. Restrictions for return varied by retailers and retail formats. Generally retailers followed the guidelines of consumer protection laws. The study discussed implications of return policy analysis.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.613-626
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• 2020

This study reconsiders covenant theology through the relationship between law and grace. In order to do this, it first evaluates whether the Sinaitic Covenant is a covenant of grace or a covenant of works. This has been in discussion for a long period of time among theologians, yet is far from settled. Traditional studies form a wide spectrum, which can be divided into at least four major branches. First, the Sinaitic Covenant is the same as the covenant of grace. Second, the Sinaitic Covenant is the same as the covenant of works. Third, the Sinaitic Covenant forms a third, independent category of covenant. Fourth, the Sinaitic Covenant exists in harmony with the covenant of grace. Each category is summarized along with its representative proponents. Also, even though the term covenant of works is not accepted as prevalently among modern theologians, observations is made on how each category connects to and continues in modern theological discussions regarding law. Special emphasis is given to the fourth category and the fourth perspective on law with respect to how they differ from the others in viewing the relationship between law and gospel. Moreover, recognizing that the unique understanding of the fourth view grows out of a careful observation of the Biblical text, the structural similarities between the Sinaitic Covenant and other Biblical covenants are compared based on the Biblical text. Based on this comparison, it is observed that God's grace and human duty coexist in several Bible covenants including the Sinaitic and New Testament covenants. From this observation, it is proved that conditionality regarding covenant fulfillment exists in them all. This conditionality does not entail from exclusiveness on the part of God, but from the weakness on the part of humans. However, some unconditional covenants, albeit few in number, can be found in the Bible. Therefore, the difference between unconditional covenants and conditional covenants is discussed. Lastly, the proper place and role of grace in covenants is studied.