• Journal of Korea Multimedia Society
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• v.17 no.7
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• pp.778-786
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• 2014

Buyer-seller watermarking protocol is one of the copyright protection techniques which combine a cryptographic protocol used in electronic commerce with a digital wetermarking scheme aiming at proving the ownership of multimedia contents and preventing the illegal reproduction and redistribution of digital contents. In this paper, it is proposed a new watermarking scheme in an encrypted domain in an image that is based on the block-DCT framework. In order to implement watermarking scheme in a public-key cryptosystem, it is divided that frequency coefficients exist as real number into integer and decimal layer. And the decimal layer is modified integer type through integral-processing. Also, for robustness and invisibility required in watermarking scheme, it is designed a direction-adaptive watermarking scheme based on locally edge-properties of each block in an image through analyzing distribution property of the frequency coefficients in a block using JND threshold.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.285-288
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• 2004

High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.

• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.131-138
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• 2005

High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.

• 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.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.1-12
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• 2009

Today, Digital Right Management (DRM) is used to protect copyrights of digital contents from illegal reproduction and redistribution. Unfortunately, current DRM systems are causing user's discomfort because of lack of mutual compatibility. In order to overcome this drawback, technologies for interoperability of heterogeneous DRM systems are developing. In this paper, we study the protection profile for conversion technologies of heterogeneous DRM systems, using the Common Criteria. Especially, this paper is written by reuse of the existing protection profile. Therefore, performance analysis reveals that efficiency of time and cost is significantly improved. This protection profile can be used by contents provider and administrator who manage user's copyrights to reference data for copyright protection.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.657-666
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• 2014

The development of ICT are turning information society into smart society which focus on mobile environment. The effect of ICT influence not only technical aspects but also societal and economic aspects. But we can't ignore the side effects of ICT, especially digital divide can cause social elimination. Digital divide is related to redistribution of wealth, so there are too many studies which deal with digital divide. But Most of these studies are focusing on physical accessibility. Also most of digital divide studies address digital divide based on demographic factors such as gender, age, income and education. Of course, these studies are important, but we expect that the aspect of digital divide is different from past digital divide. This paper deal with exploratory discussion for necessity of new digital divide conception by reviewing limitations of existing digital divide research.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.661-671
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• 2012

The purpose of this study was to analyze the core policies of local government directors by performing centrality analysis on their core policies using network text analysis method. From the research results, it was verified to some extent that major policies of local government directors were changing during the path to arrive at 5th civil election. However, according to policy type by Peterson (development policy, allocation policy and redistribution policy) it was found that they still focused on development policies. However, it is encouraging that the government directors elected in the 5th election started to pay attention to 'Culture' which is one of allocation policies.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.228-241
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• 2015

Using survey on 865 college students, this study examines college students' perceptions on older generations in Korea. College students do not perceive conflicts with the elderly severely. While they recognize that the elderly contributed to family care and economic growth, they perceive that intergenerational conflicts regarding redistribution across generations might be impending in the areas of welfare policies. Progressive students evaluate contributions of the elderly more positively and approve expanding the roles of governments in the areas of welfare policies for the elderly than do conservative students. Students with higher interests in politics also positively assess the contributions of the elderly and are more concerned with the financial sustainability of welfare policies for the elderly. However, they perceive that the possibility of intergenerational conflicts might be low. This study suggests programs to increase intergenerational cooperation between college students and the elderly.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1034-1041
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• 2011

Generally, In distributed online game server system, game maps are processed separately by means of dividing into several unit blocks. But the keeping normal distribution of user in game map is very difficult because preferences of game users are not same according to individual user's private character. For this reason, if the huge number of users concentrate on particular region of same game map at once, the game server exceed their threshold so that the system can be getting down. Conversely, the efficiency of system goes down considerably because the game server must perform map processing continuously even under user_empty situation. To solve this problem, in this paper, we propose a Map management method to control relatively normal distribution of users in game maps using Map Balance Server. In suggested model, we can reduce the load of game servers by means of turn off the game map processing temporary when a server is under user_empty situation. we also can maximize server performance by means of redistribution of map processing load among servers.

• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.69-78
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• 1986

This experiment was carried out to Investigate the environmental changes of rhizosphere, behavior of nutrient components in soul, and nutrients uptake and growth response of the tobacco plant in the condition that mulch as polyethylene film, had been removed on the ridge at the 50th day after transplanting in comparison with continuous mulching condition. The results obtained were as follows; 1. After rainfall, soil moisture content In the plow layer was greatly increased without mulch in comparison with that of the plot with mulch. As a result, leaf water potential of tobacco plant without mulch was higher than that with mulch. 2. Available nutrients such as $NH_4-N, \;NO_3-N$, and total salts in the plow layer of the plot without mulch tended to be Increased, and especially accumulated on the surface layer owing to the redistribution of soil water by rainfall during the latter growth stage after removing mulch. 3. Nutrients uptake by tobacco was much more enhanced in the plot without mulch and resulted in higher contents of total nitrogen, $NO_3-N, \;P_2O_5, \;and K_5O$ in the tobacco leaf Especially higher content of nitrogen caused the delay of maturity resulting In the increased of dry weight of top part of tobacco in the plot without mulch toned to be Increased in comparison with that in mulching condition. Content of total nitrogen, $NO_3-N$, and nicotine in flue-lured leaves was much higher in the plot without. mulch than in mulching condition, but lower content of reducing sugar in the plot without mulch resulted in lower quality of tobacco.