• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.37-42
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• 2009

Cognitive radio (CR), which is proposed as a technology that utilizes the frequency resources effectively, has studied to relive scarcity of the frequency resources. Also, FCC revises the regulation to reuse the TV white spaces for applying CR system and allows to use the TV white spaces by CR devices and use of CR device may be regularized after conversion by DTV in 2009. If CR system's signal appeared in pilot's position, pilot sensing performs false alarm detection because pilot sensing scheme confuse DTV signal and CR system. In order to improve false alarm detection, we propose distinction scheme between DTV and CR system using PN511 sequence in this paper.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.45-53
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• 2020

Blockchain can control transactions in a decentralized way and is already being considered for manufacturing, finance, banking, logistics, and medical industries due to its advantages such as transparency, security, and flexibility. And it is predicted to have a great economic effect. However, Blockchain has a Trilemma that is difficult to simultaneously improve scalability, decentralization and security characteristics. Among them, the biggest limitation of blockchain is scalability, which is very difficult to cope with the constantly increasing number of transactions and nodes. To make the blockchain scalable, higher performance should be achieved by modifying existing consensus methods or by improving the characteristics and network efficiency that affect many ways of scaling. Therefore, in this paper, we propose a cluster-based scalable PBFT consensus algorithm called CBS-PBFT which reduces the message complexity O(n²) of PBFT to O(n), which is a representative consensus algorithm of blockchain, and the validity is verified through simulation experiments.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.163-169
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• 2024

Anti-drone (anti-drone) is at the center of the debate over the failure to shoot down a North Korean drone that invaded the metropolitan area at the end of 2022. Anti-drone is a means of detecting and restraining drone flights in unauthorized airspace. Anti-drone technology is a key defense system for drone technology that is essential in the current illegal situation of various drones. We must be alert in the war in Ukraine, where the role of drones has increased. Drone attacks, which are not easy to defend, may determine the victory or defeat of the war. Competition for anti-drone technology development in countries around the world will rise. When new anti-drone technology emerges, drones that go beyond it will be developed. This study presented the current status of anti-drone by analyzing the defense system of domestic drones.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.172-177
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• 2009

Mugunghwa Satellite N0.1 is fired after operation was 13 years. The establishment of communication satellites, as well as Internet service backbone network the country, including satellite broadcasting services to provide multimedia services to general users and contribute to have a big role. High-speed Internet Access Network was expanded and satellite Internet subscribers Access Network rapidly decreasing, but it also a difficult situation, satellite communications network is still important as a component is located. Launched the first communication satellite to be launched and operated several commercial communications satellite, but satellite communications services and the pace of the system is in place. In this paper VSAT, satellite communications service to provide a service based on the status and problems of the status of operating system and will present alternative policies to solve.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.394-400
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• 2016

It is well known that the encrypted ranging signal, such as GPS P(Y) code, is immune to spoofing attack. However, in order for users to use the signal, there needs permission from the operator. And also there are many restrictions for use because of security issues. In this paper, a ground reference station equipped with high-gain directional antenna and a user receiver were simulated. In the reference station, the encrypted code can be demodulated from the high-gain signal. And then the code can be used to detect spoofing attack in the user receiver. This paper proposes the spoofing detection method using the encrypted signal and deals with simulation results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6264-6269
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• 2014

This study examined the state of the UWB frequency band of foreign policy for application to domestic findings. The results confirmed that the UWB frequency can be prescribed mainly for use in a communication service area, unlike foreign countries, such as the United States and Europe for the current technology standard. On the other hand, the expansion of the UWB service area to various fields may appear as interference in the domestic industry protection and enable these rules. Therefore, the UWB frequency should be used in other areas except for broadcast and communication, if the output meets the specified criteria, as in the case of a foreign country. This is thought to be helpful for protecting the domestic industry and activated services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8A
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• pp.723-729
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• 2011

FCC of U.S. permitted usage of unlicensed system on unused spectrum in TV white space after DTV transition. The unlicensed systems are required to avoid harmful interference to licensed users by employing geo-location database and spectrum sensing. The conventional spectrum sensing algorithms for ATSC signal were focused on detection of pilot signal. However, they can not guarantee detection of ATSC signal when pilot signal is attenuated by channel environment such as fading. To overcome drawbacks of conventional schemes, in this paper, we propose a signal detection and data fusion algorithm using cyclo-stationary feature weighted by signal energy. Simulation results verify that the proposed algorithm can provide 2dB SNR gain for 90% detection probability compare with the conventional scheme. We can reduce quiet period for spectrum sensing and improve signal detection probability by employing the proposed algorithm.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.221-229
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• 2022

With the recent full-fledged MyData service, interest in the use of personal data is increasing. However, studies on MyData are still in the early stages, focusing on legal and institutional discussions, and studies from a comprehensive perspective are insufficient. Therefore, this study aimed at finding the potential topics formed by social discussions by analyzing news data from 2018 to the present. News data analysis using LDA topic modeling were conducted and 6 potential topics including digital transformation in finance, scope of Mydata business license, amendments and data-related laws, safe use of big data, data economy promotion policy and strategy of the financial industry were derived. This study has significance in that it comprehensively viewed the issues that emerged with the MyData and deriving gaps in previous discussion. Future research is expected to identify changes after the launch of MyData service and provide specific implications through research by specific industries.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.147-153
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• 2021

The purpose of this study is to establish strategic suggestions for the direction of the drone-related business by Gyeonggi-do through a survey on the operation and actual conditions of the drone geospatial information service business experienced by Gyeonggi-do civil servants. For this purpose, as a result of surveying the demand survey of 219 people in charge of drone field work, it was analyzed by dividing it into four categories: technology-based operation support, business discovery and support, legal and institutional support, and education and public relations. As an improvement measure, technology-based operation support is to secure service operation efficiency by establishing a dedicated manpower and a dedicated organization and securing drone-related experts.The plan for improvement of project discovery and support is as follows. 1) The government proactively discovers prior research projects for project discovery and support; 2) Legal and institutional support requires support services for simplification of administration such as drone geospatial data shooting schedules and permits, 3) legal and institutional review on improving the scope and restrictions for using drone geospatial data. In the field of education and publicity, it is necessary to operate an education program on the overall operation of drones, and to conduct seminars for each field and use, and to seek activation methods through practical application guidelines for the application process and system. The limitation of this study is that the survey subjects are related to Gyeonggi-do, and in the future, survey analysis through a wide range of participants is required.