• The Bulletin of The Korean Astronomical Society
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• 제44권1호
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• pp.35.4-35.4
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• 2019

We have conducted a 22 GHz very long baseline interferometry (VLBI) survey of 281 local (z < 0.05) active galactic nuclei (AGNs) selected from the Swift Burst Alert Telescope (BAT) 70-month ultra hard X-ray (14-195 keV) catalog. The main goal is to investigate the relation between the strengths of black hole accretion and the parsec-scale nuclear jet, which is expected to tightly correlate but has not been observationally confirmed yet. The BAT AGN Spectroscopic Survey (BASS) provides the least biased AGN sample against obscuration including both Seyfert types, hence it makes an ideal parent sample for studying the nuclear jet properties of an overall AGN population. Using the Korean VLBI Network (KVN), the KVN and VERA Array (KaVA), and the Very Long Baseline Array (VLBA), we observed 281 objects with a 22 GHz flux > 30 mJy, detecting 11 targets (~4% of VLBI detection rate). This implies that the fraction of X-ray AGNs which are currently ejecting a strong nuclear jet is very small. Although our 11 sources span a wide range of pc-scale morphological types, from compact to complex, they lie on a tight linear relation between accretion luminosity and nuclear jet luminosity. Our finding may indicate that the power of nuclear jet is directly responsible for the amount of black hole accretion. We also have probed the fundamental plane of black hole activity in VLBI scale (e.g., few milli-arcsecond). The results from our high-frequency VLBI radio study support that the change of jet luminosity and size follows what is predicted by the AGN evolution scenario based on the Eddington ratio (ƛ$_{Edd}$) - column density ($N_H$) plane, proposed by a previous study.

• Archives of Plastic Surgery
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• 제48권2호
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• pp.165-174
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• 2021

Background In recent years, implant-based breast reconstruction has been performed because of its simplicity, short operation time, and rapid recovery of patients. Several studies have reported treatment methods for implant surgery-related infection, which is a serious complication. The aim of this study was to introduce our strategy for salvaging infected implants and to evaluate its effectiveness. Methods The authors performed a retrospective study of 145 cases from 132 patients who underwent implant-based breast reconstruction from January 2012 to December 2018. Empirical antibiotics were immediately administered to patients with suspected infections. The patients then underwent salvage treatment including appropriate antibiotics, ultrasonography-guided aspiration, debridement, antibiotic lavage, and implant exchange through a multidisciplinary approach. Patient demographics, operative data, duration until drain removal, adjuvant treatment, and complications were analyzed. Results The total infection rate was 5.5% (8/145). A longer indwelling catheter period and adjuvant treatment were significantly associated with infection. The salvage treatment showed a success rate of 87.5% (7/8). Seven patients who received early aggressive salvage treatment recovered from infection. One patient with methicillin-resistant Staphylococcus aureus, who received salvage treatment 11 days after symptom onset, did not respond to drainage and antibiotic treatment. That patient subsequently underwent explantation. Conclusions In implant-based breast reconstruction, prevention of infection is of the utmost importance. However, if an infection is suspected, proactive empirical antibiotic therapy and collaboration with the necessary departments are required. Through a multidisciplinary approach and proactive early management, swift and appropriate salvage should be performed.

• Journal of The Korean Astronomical Society
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• 제55권2호
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• pp.37-57
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• 2022

Using I-band images of 35 nearby (z < 0.1) type 1 active galactic nuclei (AGNs) obtained with Hubble Space Telescope, selected from the 70-month Swift-BAT X-ray source catalog, we investigate the photometric properties of the host galaxies. With a careful treatment of the point-spread function (PSF) model and imaging decomposition, we robustly measure the I-band brightness and the effective radius of bulges in our sample. Along with black hole (BH) mass estimates from single-epoch spectroscopic data, we present the relation between BH mass and I-band bulge luminosity (M_BH-M_I,bul relation) of our sample AGNs. We find that our sample lies offset from the M_BH-M_I,bul relation of inactive galaxies by 0.4 dex, i.e., at a given bulge luminosity, the BH mass of our sample is systematically smaller than that of inactive galaxies. We also demonstrate that the zero point offset in the M_BH-M_I,bul relation with respect to inactive galaxies is correlated with the Eddington ratio. Based on the Kormendy relation, we find that the mean surface brightness of ellipticals and classical bulges in our sample is comparable to that of normal galaxies, revealing that bulge brightness is not enhanced in our sample. As a result, we conclude that the deviation in the M_BH-M_I,bul relation from inactive galaxies is possibly because the scaling factor in the virial BH mass estimator depends on the Eddington ratio.

• International Journal of Computer Science & Network Security
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• 제22권5호
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• pp.342-347
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• 2022

On Cloud, the important data of the user that is protected on remote servers can be accessed via internet. Due to rapid shift in technology nowadays, there is a swift increase in the confidential and pivotal data. This comes up with the requirement of data security of the user's data. Data is of different type and each need discrete degree of conservation. The idea of data security data science permits building the computing procedure more applicable and bright as compared to conventional ones in the estate of data security. Our focus with this paper is to enhance the safety of data on the cloud and also to obliterate the problems associated with the data security. In our suggested plan, some basic solutions of security like cryptographic techniques and authentication are allotted in cloud computing world. This paper put your heads together about how machine learning techniques is used in data security in both offensive and defensive ventures, including analysis on cyber-attacks focused at machine learning techniques. The machine learning technique is based on the Supervised, UnSupervised, Semi-Supervised and Reinforcement Learning. Although numerous research has been done on this topic but in reference with the future scope a lot more investigation is required to be carried out in this field to determine how the data can be secured more firmly on cloud in respect with the Machine Learning Techniques and cryptographic methods.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제22권4호
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• pp.97-113
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• 2023

Swift and appropriate responses in emergency situations like objects falling on the road can bring convenience to road users and effectively reduces secondary traffic accidents. In Korea, current intelligent transportation system (ITS)-based detection systems for emergency road situations mainly rely on loop detectors and CCTV cameras, which only capture road data within detection range of the equipment. Therefore, a new detection method is needed to identify emergency situations in spatially shaded areas that existing ITS detection systems cannot reach. In this study, we propose a ResNet-based algorithm that detects and classifies emergency situations from vehicle camera footage. We collected front-view driving videos recorded on Korean highways, labeling each video by defining the type of emergency, and training the proposed algorithm with the data.

• Journal of Korea Society of Industrial Information Systems
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• 제14권1호
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• pp.32-42
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• 2009

Information and communication industry, which has been growing rapidly, is now leading the global economic growth, contributing a ripple effect on general business and economic structure. It is said that information and communication industry enables swift economic growth taking a role as a basic industry of information-oriented society. Especially, rapid technical innovation promotes mutual growth of other related industries and it is technology-intensive. The purpose of this research is to analyze the management efficiency of information and communication industry using DEA method, and finally suggests numerical value for inefficient organizations to improve their efficiency. CCR-I, BCC-I efficiency and RTS(Returns to scale) of 29 companies engaged in information and communication industry was evaluated. With the results, we suggested the model companies for benchmarking in information and communication industry. To summarize, 7 companies were selected with CCR-I efficiency rate 1, and 12 companies with BCC-I efficiency rate 1. RTS was finalized with 8 IRS companies, 10 DRS companies, and 11 CRS companies.

• Korea Trade Review
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• 제42권5호
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• pp.213-232
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• 2017

A Bank Payment Obligation is now in operation as payment instruments in the business of Supply Chain Finance since 2013. The BPO is an irrevocable undertaking of the Obligor Bank subject to the successful electronic matching of all required Data Sets with the established Baseline in the TMA. Although the BPO should be regarded as similar to a Letter of Credit, it is a new payment solution based on a technology and data-driven mechanisms. The BPO is different from the letter of credit in their structure such as a bank to bank obligation, an automated matching engine, a transfer and confirmation of the Credit, etc. The BPO can also be used more effectively on a stand-alone solution as an electronic alternative to the traditional instruments. it will provide a new range of solutions to meet the ever-changing needs of the trade customers. However, the BPO could be raised several issues including an assurance of payment between recipient banks and sellers because the BPO is a bank-to-bank obligation. The URBPO do not applies to the relationships between banks and their business clients. So, the primary objective of this paper is to promote the institutional understanding and present the implications by reviewing the majn issues in the BPO as comparision with the Letter of Credit from the institutional point of view. This research was also based on documentary research focusing on the preceding research and the materials of ICC and SWIFT.

• Korea Trade Review
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• 제43권4호
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• pp.1-25
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• 2018

Bank payment obligations (BPO) have been used since 2013 as a payment solution in the business of supply chain finance. The BPO is an irrevocable undertaking of the obligor bank subject to the successful electronic matching of all required data sets with the established baseline in the TMA. Although the BPO should be regarded as similar to a letter of credit, it is a new payment solution based on advanced technology and data-driven mechanisms. The BPO differs from the credit in institutional terms such as bank-to-bank obligations, automated matching engines, and transfer and confirmation, etc. The BPO can also be used effectively as a stand-alone electronic solution to traditional instruments. it provides a new range of solutions to meet the ever-changing needs of trade customers. However, Operation of the BPO can leads to several issues including an assurance of payment between recipient banks and sellers because the BPO is a bank-to-bank obligation. The URBPO does not apply to relationships between banks and their business clients. So, the primary objective of this paper is to promote institutional understanding and present implications by reviewing major issues concerning the BPO as compared with the letter of credit from the institutional point of view. This research was based on documentary research focusing on the preceding research and the materials of ICC and SWIFT.

• Korea Trade Review
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• 제42권5호
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• pp.233-252
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• 2017

The fast changes of global financial environment in recent years increase the risk of trade settlement. This means are required to minimize risk of non payment and to maximize secure payment. Open Account trade accounts for 90% of global trade flows. The O/A system means that the goods, along with all the necessary documents, are shipped and delivered before payment is due, usually within a time frame from 30 to 90 days. Meanwhile, Korean small and medium-sized export enterprises are compelled to globalize their activities owing to limitation and competitiveness of domestic marketplace. To keep face with the global trade settlement system and to support globalization of small and medium-sized export firms, the BPO together with Supply Chain Finance will be solutions. The introduction of the BPO system will allow banks to broaden O/A offerings to their client base and due to secure safety, sellers could ship the goods without delay according to orders and buyers could settle promptly by payment undertaking of correspondent banks. Therefore, it is more effective for companies which have sustainable customers and stable transaction. This study take a look at the trend of the global payment systems and suggested limitation of existed payment in order to derive improvement measures of electronic payment for small and medium-sized export enterprises.

• The Journal of the Convergence on Culture Technology
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• 제9권4호
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• pp.699-706
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• 2023

Recently, the 4 generation industry revolution is developed with advanced and combined with a variety of new technologies. Conventional healthcare system is applied with IoT application. It provides many advantages with mobility and swift data transfers to patient and doctor. In despite of these kinds of advantages, it occurred security issues between basic devices and protocols in their applications. Especially, internet of things have restricted and limited resources such as small memory capacity, low capability of computing power, etc. Therefore, we can not utilize conventional mechanism. In this paper, we analyzed attacks and vulnerability in terms of security issues. To analyze security structure, features, demands and requirements, we solve the methods to be reduced security issues.