• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.197-199
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• 2016

In this paper, we investigate a market equilibrium in multi-channel sharing cognitive radio networks (CRNs): it is assumed that every subchannel is orthogonally licensed to a single primary user (PU), and can be shared with multiple secondary users (SUs). We model this sharing as a spectrum market where PUs offer SUs their subchannels with limiting the interference from SUs; the SUs purchase the right to transmit over the subchannels while observing the interference limits set by the PUs and their budget constraints. The utility function of SU is defined as least achievable transmission rate, and that of PU is given by the net profit. We define a market equilibrium in the context of extended Fisher model, and show that the equilibrium is yielded by solving an optimization problem, Eisenberg-Gale convex program.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.57.3-57.3
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• 2018

KVN 수신기는 22/43/86/129GHz 주파수 대역의 우주전파를 관측할 수 있는 4채널 동시 관측 시스템의 핵심으로 다수의 제어 및 모니터 항목이 존재한다. 대표적인 예로 Synthesizer, Pcal, LO, Vacuum, Cryogenic Temperature 등이 있으며 이와 관련된 여러 인스트루먼트가 21m 전파망원경의 하부단에 위치한 수신기실 내에 분산 배치되어 있다. 이에 대한 효율적인 제어를 위해서는 사용자 컴퓨터 관점에서 두 가지 조건이 충족되어야 한다. 첫째, 물리적으로 분산된 인스트루먼트에 대한 접근 및 변경이 용이해야 하고, 둘째는 단일 인터페이스 상에서 다양한 인스트루먼트를 하나로 통합하는 확장성이 보장되어야 한다. 이러한 요건을 고려하여 KVN은 산업 분야에서 널리 쓰이고 있는 프로피버스를 수신기 시스템의 제어를 위한 기반 인터페이스로 활용 중에 있고, 추가 기능 요구에 효율적으로 대처하고 있다. 본 발표에서는 먼저 KVN 수신기 시스템을 구성하는 인스트루먼트에 대해 살펴보고자 한다. 그리고 이를 효율적으로 제어하기 위한 기반 인터페이스로서 프로피버스 구축 및 활용 현황에 대해 논하고자 한다.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.163-170
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• 2021

As a big data is being used in various industries, big data market is expanding from hardware to infrastructure software to service software. Especially it is expanding into a huge platform market that provides applications for holistic and intuitive visualizations such as big data meaning interpretation understandability, and analysis results. Demand for big data extraction and analysis using social media such as SNS is very active not only for companies but also for individuals. However despite such high demand for the collection and analysis of social media data for user trend analysis and marketing, there is a lack of research to address the difficulty of dynamic interlocking and the complexity of building and operating software platforms due to the heterogeneity of various social media service interfaces. In this paper, we propose a method for developing a framework to operate the process from collection to extraction and classification of social media data. The proposed framework solves the problem of heterogeneous social media data collection channels through adapter patterns, and improves the accuracy of social topic extraction and classification through semantic association-based extraction techniques and topic association-based classification techniques.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.147-154
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• 2020

It is difficult to educate the overall operation of public and private blockchains with different characteristics. Recently, most education for blockchain is targeted at public blockchains such as Bitcoin and Ethereum. However, in an actual business environment, a private blockchain such as HyperLedger Fabric is used because access to corporate data is controlled through user authentication. In the case of HLF-based education, it is necessary to understand various components that are not in the public blockchain, such as peers, orderers, and channels. In this paper, a lab framework for HLF is designed for an efficient and systematic understanding of the functions and operations. The framework consists of HLF network, chaincode, and decentralized software control functions. Through the framework, the network configuration, distribution and activation of chaincode, and dApp execution process were checked step by step, and it was very easy to understand the overall flow for blockchain services. In addition, it is expected that a systematic understanding of the overall flow will be possible even in future network expansion.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.507-519
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• 2021

This paper attempts to explore advertising factors that affect TikTok advertising effectiveness by identifying motivations to use a short-form video social media platform, TikTok and further looking at perceptions of and attitudes toward TikTok advertising. The results of in-depth interviews with 20s-30s TikTok users suggest that users are motivated to use TikTok for information and fun. Further, TikTok is characterized as a short-form video, rich contents, and a novel format. Regarding TikTok advertising, the results reveal that usefulness, enjoyment, easiness of advertising skip, sense of closeness, and interaction are significant factors of TikTok advertising. Finally, it is suggested that users respond to the advertising by clicking 'like', writing comments, sharing, clicking 'purchase link'/advertiser's website, and creating user-created contents and so on. These findings theoretically contribute to the literature on social media advertising, and practically offer strategic guidelines for TikTok advertising.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.103-110
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• 2022

Botnets have been exploited for a variety of purposes, ranging from monetary demands to national threats, and are one of the most threatening types of attacks in the field of cybersecurity. Botnets emerged as a centralized structure in the early days and then evolved to a P2P structure. Bitcoin is the first online cryptocurrency based on blockchain technology announced by Satoshi Nakamoto in 2008 and is the most widely used cryptocurrency in the world. As the number of Bitcoin users increases, the size of Bitcoin network is also expanding. As a result, a botnet using the Bitcoin network as a C&C channel has emerged, and related research has been recently reported. In this study, we propose an encrypted botnet C&C communication mechanism and technique in the Bitcoin network and validate the proposed method by conducting performance evaluation through various experiments after building it on the Bitcoin testnet. By this research, we want to inform the possibility of botnet threats in the Bitcoin network to researchers.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.19-25
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• 2023

In this paper, we propose a method for improving raw images captured in a low light condition based on deep learning considering the image signal processing. In the case of a smart phone camera, compared to a DSLR camera, the size of a lens or sensor is limited, so the noise increases and the reduces the quality of images in low light conditions. Existing deep learning-based low-light image processing methods create unnatural images in some cases since they do not consider the lens shading effect and white balance, which are major factors in the image signal processing. In this paper, pixel distances from the image center and channel average values are used to consider the lens shading effect and white balance with a deep learning model. Experiments with low-light images taken with a smart phone demonstrate that the proposed method achieves a higher peak signal to noise ratio and structural similarity index measure than the existing method by creating high-quality low-light images.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.175-184
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• 2022

Travel YouTubers who cross the boundary between tradition and novelty communicate by sharing their activities with others through SNS-based media. Media content should not only satisfy individuals, nor should it be too purpose-oriented. YouTube channels should be operated so that users can easily access content naturally, and more diverse methods can be pursued based on usage patterns and satisfaction theory. This study is about the type of perception of Generation Z on travel YouTube titles. As a result of conducting QUANL program analysis on 34 Q samples and 28 P samples from the Q methodological perspective, a total of three types were found. For types with unique characteristics, the first type was named "attention of keywords that draw imagination," the second type was "preferred to stories that stimulate curiosity," and the third type was "image satisfaction reflecting expectations." In addition, considering the characteristics of each type found, the scalability and strategic plan of the activities that Generation Z travel YouTubers want to unfold were presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.99-104
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• 2022

In the age of convergent media, traditional media and network media are highly integrated, and benefits are shared, which promotes the increase of traditional culture communication channels, the change of communication methods, and the change of the mode of interaction with audiences. This article analyzes the difficulties of traditional culture dissemination by enumerating some excellent cultural programs in China. At the same time, combined with the current situation of convergence media, it discusses how to transform invisible traditional culture into visual digital content, and make it widely disseminated by means of convergence media. It provides reference for the development of traditional culture, and has enlightening significance for creating high-quality cultural programs and spreading mainstream culture.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.67-80
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• 2022

The purpose of this study is to clarify the meaning and characteristics of re-organized shortform contents, which is centered on media companies to edit and service existing broadcast content. For this, KBS, MBC, SBS, JTBC, and tvN's entire drama videos and representative entertainment programs opened on the Naver TV platform from 2014 to 2021 were selected for analysis and a synchronic and diachronic approach was conducted at the same time. As a result of the analysis, quantitative and qualitative expansion was made, with the number and form of videos provided by both dramas and entertainment programs diversifying from a synchronic approach. In particular, in the case of special videos, the meaning as independent content was also strengthened, such as sequencing centered on characters, themes, and materials. It was confirmed that thumbnails and titles were also formalized as tags as paratexts that act as curation for searches. From a diachronic point of view, it was found that re-organized shortform contents is considered to be character-oriented contents and independent viewing context through comparison with real-time views and original videos. This study is significant as an attempt to capture the meaning and phase change of shortform contents, which was considered incidental.