• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1853-1859
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• 2008

IGBT modules are designed for low loss, rugged for all environments and user friendly. Low on state saturation voltage with high switching speed is the primary concerns. In this paper selection of IGBT, module ratings and characteristics are discussed. The IGBT design topic of protection against over voltage and over current are covered. Emphasis on turn off switching, short circuit switching and necessary precautions are dealt. Selection of IGBT device, gate drive power, and its lay out considerations are covered in detail.

• Journal of Internet Computing and Services
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• v.21 no.3
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• pp.1-9
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• 2020

Along with the growth of Blockchain, DApp (Distributed Application) is getting attention. As interest in DApp grows, market size continues to grow and many developers participate in development. Many developers are using API(Application Programming Interface) services to mediate Blockchain nodes, such as Infura, for DApp development. However, when using such a service, there is a serious risk that the API service operator can violate the user's privacy by 1 to 1 matching the account address of the Transaction executed by the DApp user with the IP address of the DApp user. It can have an adverse effect on the reliability of public Blockchains that need to provide users with a secure DApp service environment. The proposed Blockchain platform is expected to provide user privacy protection from API services and provide a reliable DApp use environment that existing Blockchain platforms did not provide. It is also expected to help to activate DApp and increase the number of DApp users, which has not been activated due to the risk of an existing privacy breach.

• Journal of Internet Computing and Services
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• v.18 no.5
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• pp.31-38
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• 2017

Recently with the rapid development of LBS (Location-based Services) technology, approaches of protecting user's location have gained tremendous attentions. For using LBS, users need to forward their real locations to LBS server. However, if the user sends his/her real location to LBS server, the server will have the all the information about user in LBS. Moreover, if the user opens it to LBS server for a long time, the trajectory of user may be released. In this paper, we propose GTC (Grid-based Trajectory Cloaking) method to address the privacy issue. Different from existing approaches, firstly the GTC method sets the predicting trajectory and divides the map into $2^n*2^n$ grid. After that we will generate cloaking regions according to user's desired privacy level. Finally the user sends them to LBS server randomly. The GTC method can make the cost of process less than sequential trajectory k-anonymity. Because of confusing the departure and destination, LBS server could not know the user's trajectory any more. Thus, we significantly improve the privacy level. evaluation results further verify the effectiveness and efficiency of our GTC method.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.129-137
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• 2009

While the broadband network and multimedia technologies have been developing, the commercial market of digital contents also has been widely spreading with recently starting IPTV. As the IPTV services are getting to be generalized and popularized, the contents protection and authentication system tends to draw more attentions. So we need a system that can protect contents and allow only authenticated person to use right service by controling user authority and using content encryption. Until now, the conventional protection and authentication system is taking advantages of merits both in CAS and DRM. But the weak point of this system are in high costs, complexity and using HW. For resolving these problems, in this paper, we proposed IPTV contents protection and authentication system using OTP. When we transmit the content encrypted by OTP key using contents delivery technology, we operate XOR with contents using another settop-box's OTP key which was transmitted from distribution server. And contents are reconstructed and transmitted to the settop-box, In the end, downloaded content are encrypted by OTP key and are superior in content protection when contents redistribution. Since OTP use double-authentication elements in encryption process, this method is excellent in content protection. And it is very effective in cost aspect because it could be implemented by SW program. Another benefit is that we can shorten the development time period. In this paper, we propose and find its possibility as a new content protection and authentication method suitable for IPTV services.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.913-921
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• 2017

Mobile electronic commerce is rapidly growing up on the strength of popularization of smart devices such as smart phone followed by internet user increase. Concurrently with this, the anxiety on information security and personal information leakage of the user of mobile electronic commerce significantly built up in recent. In this respect, the information security and personal information protection should be become aware of their importance for the sustainable expansion and development of mobile commerce. Based on the demands as mentioned, this study analyzed the effects of the awareness of personal information security on recognized risk, recognized confidence and intent to use. The result of this study indicates that information security and personal information protection contribute to improvement in confidence by decreasing anxiety and uncertainty related to mobile commerce. Reduction of anxiety and uncertainty implies a crucial point that affects psychological mechanism making intent to use higher.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8908-8914
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• 2015

The Internet continues to grow and develop, but there are going to generate a variety of Internet attacks that exploit it. In the initial Internet environment, the attackers maliciously exploited Internet environments for ostentations and hobbies. but these days many malicious attempts purpose the financial gain so systematic and sophisticated attacks that are associated with various crimes are occurred. The structures, such as viruses and worms were present in the form of one source multi-target before. but recently, APT(Advanced Persistent Threat, intelligent continuous attacks) in the form of multi-source single target is dealing massive damage. The performance evaluation analyzed whether to generate audit data and detect integrity infringement, and false positives for normal traffic, process detecting and blocking functions, and Agent policy capabilities with respect to the application availability.

• Convergence Security Journal
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• v.20 no.2
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• pp.37-52
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• 2020

The EU, the United Kingdom and South Korea are actively pursuing open banking to open financial information to fintech companies for financial structure reform and convenience of financial consumers. As open banking is gradually activated, the importance of stability and protecting users of open banking will increase. In particular, Korea has an electronic financial transaction law that has been in effect since 2007 to secure the stability and reliability of electronic financial transactions, but it is difficult to apply to participating organizations in open banking, so there is a risk of preventing security accidents and weakening user protection in open banking. Therefore, this paper examines the foreign legal system of open banking and analyzes the structure and characteristics of domestic open banking and suggests the ways to improve regulations necessary to strengthen open banking stability and user protection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1344-1349
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• 2012

The Korean DGPS station transmits the 200 bps GPS enhancement signal using the MSK modulation in frequency range of 283.5 kHz to 325 kHz. The land-based stations of 6 sites provide the service area of 80 km with the output power of 500 W. The ocean-based stations of 11 sites provide the output power of 300 W, which provide the DGPS service to 185 kM. Some places are serviced from two or three DGPS stations. The interferences among the DGPS stations using the high power can be occurred. Also, the performances of the user terminasl in dual service area can be degraded. In this paper, the protection ratios for the DGPS service are defined. Using the MF wave propagation model, the interferences among the DGPS stations and the adjacent wireless ground stations are analyzed. Also, the performances of DGPS user terminals are analyzed in the viewpoint of interference.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3213-3217
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• 2009

Distribution, duplication and manipulation of the digital contents are very easy due to the characteristics of the digital contents. Thus, damages of invasion of property right rapidly increase due to infringement of copyright for the digital contents. To prevent illegal use and to settle conflict about ownership of the digital contents, continuous efforts with enormous expense are devoted. In this paper, we design and implement real-time audio watermarking system to protect ownership and copyright for the digital contents. The proposed system also clarifies where the responsibility about the illegal distribution lies. The system has convenient user interface so that general administrator without an expert knowledge of the protection of copyright can use easily. In addition, unlike the traditional watermarking system, our system has merit to offer information about the illegal distribution for clear post-management.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.58
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• pp.38-49
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• 2006

In order to increase the spectrum efficiency, recently, there is the number of studies for CR technology. For instance, IEEE 802.22 WRAN(Wireless Regional Area Network) WG considered the CR technology as a solution of WRAN system to serve the high speed internet service(1.5 Mbps down stream and 384 kbps up stream) in 100 km overall coverage and 54 MHz-746 MHz band. Basically, in MAC point of view, the WRAN system have been standardizing based on the IEEE 802.16 MAC layer features such as Data transmission method, QoS provision and Bandwidth request schemes. Additionally, the WRAN system further include CR nature functions such as incumbent user protection, self coexistence which would be importantly considered. Also, the inherent WRAN functions are added such as channel bonding and fractional bandwidth usage. This paper mainly explained frame structure, IU protection, self coexistence which are key functions of WRAN system. Finally, in this paper, we expressed a prospect of IEEE 802.22 WRAN standardization.