• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1179-1195
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• 2018

Recently, a variety of attacks on web services have been occurring through a multiple access environment such as PC, tablet, and smartphone. These attacks are causing various subsequent damages such as online fraud transactions, takeovers and theft of accounts, fraudulent logins, and information leakage through web service vulnerabilities. Creating a new fake account for Fraud attacks, hijacking accounts, and bypassing IP while using other usernames or email addresses is a relatively easy attack method, but it is not easy to detect and block these attacks. In this paper, we have studied a method to detect online fraud transaction and obsession by identifying and managing devices accessing web service using web-based device fingerprinting. In particular, it has been proposed to identify devices and to manage them by scoring process. In order to secure the validity of the proposed scheme, we analyzed the application cases and proved that they can effectively defend against various attacks because they actively cope with online fraud and obtain visibility of user accounts.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.147-152
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• 2002

In the preceding tests of Sub.(Ⅰ) engines, it was observed that the heat resistant capability of the engines was not enough, and the design of Sub.(Ⅰ) engines was modified to satisfy the mission requirement. Sub.(Ⅰ) Mod. engines have three major design parameters - the arrangement of main injectors, the impinging angle of main injectors and thermal barrier coating. More than 20 experiments were carried out to evaluate engine performance and heat resistance capability with respect to design parameters. Analysing the result of Sub.(Ⅰ) and Sub.(Ⅰ) Mod. engine tests, it is found that the decreased impinging angle, adopting the H-type arrangement(rather than radial type arrangement), and adopting the thermal barrier coating can increase heat resistance capacity substantially. The result show that the performance variation by design change is below 5 percents and the radial type arrangement of injectors has higher performance than H-type. However, the performance of 15°impinging angle engine is higher than that of 20°impinging angle engine, which is inconsistent to our expectation. High frequency instabilities may cause such phenomenon, which will be verified by a series of tests.

• Analytical Science and Technology
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• v.26 no.3
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• pp.211-221
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• 2013

This research aims to examine compositional and microstructural properties of grayish-blue-powdered celadon in Wonju Beopcheon-temple site. X-ray fluorescence sequential spectroscopy (XRF) with micro-point analysis, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were applied to determine the chemical composition, microstructure and crystallinity of samples, respectively. As a result, the average compositions of bodies were low silica ($RO_2$) and high flux (RO+$R_2O$). Owing to the high content of calcium oxide the glaze is considered lime type between limealkali type. The body of celdon sheard was found quarts, mullite, microcline, albite. Especially, the body's chemical compositions were compared to the results of previous studies by using a Seger formula. The compositional properties of Grayish-blue-powdered celadon in Wonju Beopcheon-temple site showed diffrently from the the other grayish-blue-powdered celadon.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.149-164
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• 2019

Digital Transformation and the Fourth Industrial Revolution, electronic financial services should be provided safely in accordance with rapidly changing technology changes in the times of change. However, telecommunication finance fraud (voice phishing) accidents are currently ongoing, and various efforts are being made to eradicate accidents such as legal amendment and improvement of policy system in order to cope with continuous increase, intelligence and advancement of accidents. In addition, financial institutions are trying to prevent fraudulent accidents by improving and upgrading the abnormal financial transaction detection system, but the results are not very clear. Despite these efforts, telecommunications and financial fraud incidents have evolved to evolve against countermeasures. In this paper, we propose an intelligent over - the - counter financial transaction system modeled through scenario - based Rule model and artificial intelligence algorithm to prevent financial transaction accidents by voice phishing. We propose an implementation model of artificial intelligence abnormal financial transaction detection system and an optimized countermeasure model that can block and respond to analysis and detection results.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.472-483
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• 2019

This study purposed to analyze how teacher experience of instructional change (EIC), teacher morale (TM), and school climate (SC) mediate or moderate the relationship between teacher efforts on instructional improvement (EII) and teacher efficacy (TE). For the purpose, the 6th year data of Gyeonggi Education Panel Study (GEPS) which was administered in 2017 for the 9th grade students and their teachers from 197 middle schools in Gyeonggi Province was used. As results, the mediation effects of EIC on the link between EII and TE was found only under the innovative climate. The moderation effects of TM on the connection between EIC and TE were appeared in both of the permissive and the innovative climate. Finally, the moderated mediation effects of the TM in the innovative climate were bigger rather than in the permissive climate.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.173-182
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• 2022

In this paper, we propose a machine learning model that can prevent fraudulent transactions in advance and interpret them using the XAI approach. For the experiment, we collected a real data set of 12,258 mobile phone sales posts from Joonggonara, a major domestic online C2C resale trading platform. Characteristics of the text corresponding to the post body were extracted using Doc2vec, dimensionality was reduced through PCA, and various derived variables were created based on previous research. To mitigate the data imbalance problem in the preprocessing stage, a complex sampling method that combines oversampling and undersampling was applied. Then, various machine learning models were built to detect fraudulent postings. As a result of the analysis, LightGBM showed the best performance compared to other machine learning models. And as a result of SHAP, if the price is unreasonably low compared to the market price and if there is no indication of the transaction area, there was a high probability that it was a fraudulent post. Also, high price, no safe transaction, the more the courier transaction, and the higher the ratio of 0 in the price also led to fraud.

• Korea Trade Review
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• v.43 no.4
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• pp.89-110
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• 2018

This paper reviews the practical operations and exceptions to the independent principle by analyzing the leading cases of English documentary credit transactions. A bank's undertaking in L/C transactions differentiates between underlying contract and other contracts. The autonomy principle is the key principle governing L/C, but this principle may be connected with unfair (unjust) payment. English Law is strongly influenced by the developments in American Law in the case of fraud, but traditionally, British courts has been very reluctant to interfere in banks' independent undertaking under the L/C. The position of British case law relating to fraud is based on Sztejn. In practice, British courts recognize fraud as an exception to the autonomy principle in which the case is sufficiently serious to render it unjust to permit the beneficiary to receive payment. British case law has historically taken a narrow approach toward intervention in the independent principle of documentary credit. Therefore, innocent parties including beneficiaries are protected by these regulations regarding fraud.

• Korean Journal of Heritage: History & Science
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• v.54 no.4
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• pp.192-211
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• 2021

In Seongju, Gyengsangbuk-do, the Placenta Chamber (胎室, Taesil) of 18 sons and a son of the crown prince of King Sejong(世宗大王) is located in one place. Taesil refers to the place where the umbilical cord and placenta, which are separated when the baby is born, are placed in a jar made of pottery and stone box and then buried on the ground. The placenta chamber in Seongju has the Buncheong ware (粉靑沙器) cover buried on the ground to protect the baby's placenta. These covers are all hemispherical, with a diameter of more the 20cm. The decorations were made using black and white inlaid techniques only on the outside. The Buncheong ware cover with this shape and pattern has been confirmed only in the placenta chamber in Seongju. This study targets 6 of the Buncheong ware cover whose owners were identified, when and where they were prepared, what the stylistic features and meanings are, and where it was produced. The results of the study are as follows. First, ss a result of reviewing the production background and procurement system of this bowl, it was inferred that it was sourced from Jangheunggo (長興庫) at the central government office, between 1436 and 1439, when the event to bury the placenta of royal members in the ground was the most active. Second, it analyzed the unique features of this cover, such as the shape, pattern, and baked traces. The shape and pattern were compared to the ritual objects contained in the Sejong Silok Oryeui (『世宗實錄』 「五禮」, Five Rites of King Sejong Chronicle) and the lid of the royal placenta jar made in the 15th and 16th centuries. Third, this study suggests that the baking method was based on the shape and location of the traces remaining outside the cover. Finally, the following data were used to estimate the production site: the relationship with the 'Jagiso (磁器所, ceramic workshop) registered in the Sejong Silok Jiriji (『世宗實錄』 「地理志」, Geographical Appendix of King Sejong Chronicle); various records of contribution and dedication about the Buncheong ware made here; and the Buncheong ware and related tools excavated from the kiln site in the area. The place where the Buncheong ware cover was produced is estimated to be the most likely production site for the kiln site in Chunghyo-dong Kiln Site, located in Jeolla-do province by synthesizing the data above.

• Conservation Science in Museum
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• v.8
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• pp.31-40
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• 2007

As part of supporting projects, the conservation science team of National Museum of Korea has treated 12 items of the porcelains entrusted by Jeonju National Museum for conservation. This paper is about the porcelains called the rice-bale-shaped battle white porcelain (No. Junju 97) and the big jar with incised fish design buncheon ware (No. Junju 5630) among the 12 items of porcelains finished with treatment, and by analyzing the information collected in the process of treating the rice-bale-shaped battle white porcelain, the manufacturing method and the use of the needle was presumed. As the big jar with incised fish design buncheon ware had been damaged extensively, it was unclear whether it could be repaired or not, but now I am going to introduce how it can be repaired more efficiently.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.293-298
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• 2006

For this study, Clinical evaluation of the diverse Autorefractors was performed to examine validity and repeatability compared with subjective refraction. Measurements of refractive error were performed on 212 eyes of 106 subjects subjectivly noncycloplegic. Intersession repeatability of the Autorefractors were also assessed on all 106 subjects together with intersession repeatability on 7 to 14 days intervals. Spherical powers of subjective refraction and autorefractions by Autorefractors were analyzed by paired T-test.