• Journal of the Korean Society for Library and Information Science
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• v.53 no.1
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• pp.83-108
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• 2019

This study investigated South Korean citizens' political communication and deliberation through Twitter during the 2014 General Election, focusing on influential opinion leaders' political information behaviors. Individual semi-structured interviews were administered with 13 opinion leaders using the multiple interview modes of email interviews, Skype interview and face to face interviews. Through the analytical lens of the theory of Information Worlds, the chosen social types and social norms of opinion leaders impacted their political information behaviors, including how they assessed, shared, exchanged, or avoided information, and, in turn, created boundaries between and around their information worlds that allowed for both conflict and synergy.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.85-90
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• 2019

This paper is a study on IoT based map inside the building and fire perception system using microprocessor and LABVIEW program. The smart control system implemented in this paper is designed to identify the location of fire by using microprocessor, flame detection sensor, carbon monoxide sensor and temperature sensor, and to guide the optimal travel route through Zigbee communication. And the proposed system uses QR code to interoperate with smartphone. The coordinator control verified that the sensor value of the smart control system installed through the LABVIEW software was confirmed. The IoT based control system studied in this paper was implemented with Arduino mega board and LABVIEW software, and the operation status was confirmed by display device and coordination.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.130-137
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• 2019

In this study, a centrifugal seawater cooling pump was analyzed to investigate its cavitation behavior over different operating flow rates. 3D two-phase simulations were carried out with ANSYS-CFX commercial code. The $k-{\varepsilon}$ turbulence and Rayleigh-Plesset cavitation models were employed in the simulations. A head drop characteristics curves for three discharge rates was built based on numerical predictions. At higher flow rates, the impeller was more vulnerable to bubble cavitation. The 3 % head drop points of the pump working at 0.7Q, Q, and 1.3Q (Q: design flow rate) corresponded with NPSHa 1.21 m, 1.83 m, and 3.45 m, respectively. The volume of vapor bubbles was estimated and cavitation locations were anticipated to visualize the development of the cavity within the impeller. Moreover, the distribution of pressure coefficient and a blade loading chart are specifically presented, bringing out the harmful impacts of cavitation on the pump operation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.596-603
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• 2019

A reprogramming operation is necessary to update the software code of the node to change or update the functionality of the deployed node in wireless sensor networks. This paper proposes an optimization algorithm that minimizes the transmission energy of a node for the purpose of reprogramming a node in wireless sensor networks. We also design an algorithm that keeps energy consumption of all nodes balanced in order to maintain the lifetime of the network. In this paper, we propose a Tabu search algorithm with a new neighborhood generation method for minimizing transmission energy and energy consumption in wireless sensor networks with many nodes. The proposed algorithm is designed to obtain optimal results within a reasonable execution time. The performance of the proposed Tabu search algorithm was evaluated in terms of the node's transmission energy, remaining energy, and algorithm execution time. The performance evaluation results showed better performance than the previous methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1369-1374
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• 2021

Recently, controversy has been raised over the security and safety of Chinese-made network equipment (Huawei 5G), apps (TikTok, etc.). In particular, according to the results of the Ministry of Defense investigation in 2020, malicious codes were found in CCTVs made in China that were delivered as military surveillance equipment used as a coast guard system, and specific information was remotely transmitted to a Chinese server. The safety issues of these Chinese security products can be questioned as being systematically led by the state rather than by companies or individuals. In this paper, we perform network and process level analysis of 360 Total Security(360 TS), a Chinese antivirus software. In addition, it compares and analyzes the domestic cloud-based vaccine V3 Lite product. Through this, the safety of Chinese security solutions is checked and information leakage and risks are suggested.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.33-38
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• 2019

In this paper, we propose a new blockchain technology that could comply with GDPR. The proposed model can prevent illegal access by controlling access to the personal information according to a access policy. For example, it can control access to the information on a role-basis and information validation period. The core mechanism of the proposed model is to encrypt the personal information with public key which is associated with users attributes policy, and then decrypt it with a private key and users attributes based on a Attribute-based Encryption scheme. It can reduce a trusted third-part risk by replacing it with a number of nodes selected from the blockchain. And also the private key is generated in the form of one-time token to improve key management efficiency. We proved the feasibility by simulating the proposed model using the chaincode of the Hyperledger Fabric and evaluate the security.

• Journal of the wind engineering institute of Korea
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• v.22 no.4
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• pp.163-169
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• 2018

In this study, wind loads exerted on the offshore wind turbine rotor in parked condition were predicted with variations of wind speeds, yaw angles, azimuth angle, pitch angles, and power of the atmospheric boundary layer profile. The calculated wind loads using blade element theorem were compared with those of estimated aerodynamic loads for the simplified blade shape. Wind loads for an NREL's 5 MW scaled offshore wind turbine rotor were also compared with those of NREL's FAST results for more verification. All of the 6-component wind loads including forces and moments along the three axis were represented on a non-rotating coordinate system fixed at the apex of rotor hub. The calculated wind loads are applicable for the dynamic analysis of the wind turbine system, or obtaining the over-turning moment at the foundation of support structure for wind turbine system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.129-137
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• 2008

As the use of the internet increases, the distribution of spam mail has also vastly increased. The email's main use was for the exchange of information, however, currently it is being more frequently used for advertisement and malware distribution. This is a serious problem because it consumes a large amount of the limited internet resources. Furthermore, an extensive amount of computer, network and human resources are consumed to prevent it. As a result much research is being done to prevent and filter spam. Currently, research is being done on readable sentences which do not use proper grammar. This type of spam can not be classified by previous vocabulary analysis or document classification methods. This paper proposes a method to filter spam by using the subject of the mail and N-GRAM for indexing and Bayesian, SVM algorithms for classification.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.51-61
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• 2009

Recently, the cyber-attacks using botnets are being increased, Because these attacks pursue the money, the criminal aspect is also being increased, There are spreading of spam mail, DDoS(Distributed Denial of Service) attacks, propagations of malicious codes and malwares, phishings. leaks of sensitive informations as cyber-attacks that used botnets. There are many studies about detection and mitigation techniques against centralized botnets, namely IRC and HITP botnets. However, P2P botnets are still in an early stage of their studies. In this paper, we analyzed the traffics of the Peacomm bot that is one of P2P-based storm bot by using honeynet which is utilized in active analysis of network attacks. As a result, we could see that the Peacomm bot sends a large number of UDP packets to the zombies in wide network through P2P. Furthermore, we could know that the Peacomm bot makes the scale of botnet maintained and extended through these results. We expect that these results are used as a basis of detection and mitigation techniques against P2P botnets.

• Knowledge Management Research
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• v.22 no.2
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• pp.77-93
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• 2021

In order to continue to grow in response to the rapidly changing industrial environments, companies must retain technological innovation capabilities and enhance market competitiveness. When competition is intensifying for creating new businesses and developing new products through technology commercialization, creating and utilizing technology convergence performance is an important means to create new competitiveness. However, there has been a lack of effort to systematically understand the level of technology convergence performance of the enterprise and to understand its relationship with management performance. In this paper, we develop a new analytical index by segmenting the technology convergence into patent variety, balance and disparity using patented IPC code information based on the concepts presented in existing diversity studies. In addition, 4,522 patents granted for three years between 2013 and 2015 by 219 KOSDAQ companies belonging to the domestic ICT convergence industry were analyzed to demonstrate that the level of technology convergence performance is positively related to sales growth rate in 2016.