• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.585-588
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• 2002

Grid provides integral ing system that enables to use distributed computing resource and services as adapts traditional infrastructures to overcome the distributed computing environments. But, computing today is moving away from a restriction of the desktop, becoming diffused into our surrounding and onto our personal digital devices. In such mobile computing environments, users expects to access resource and services at any time from anywhere in such Mobile-Grid computing. This expectation results security issues, since the computing environments is expanded. This paper describes the security challenges in Mobile-Grid computing, explaining why traditional security mechanism fail to meet the demands of these environments. This paper describes policy driven security mechanism enabled entity to use service and data in trust Mobile-Grid environments and a set of security service module that need to be realized in the Mobile-Grid security architecture presents a set of use pattern that show hew these modules can be used for billing service in a secure Mobile-Grid environments.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.119-125
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• 2013

The amount of digital content grows exponentially by the development of the internet and the change of computing environments and the target also is getting wider. The industry using this digital content has been growing greatly. However, the distribution of pirated digital content is increasing using internet because digital content is easy to store and transmit and the damage is growing. In this paper, we propose safety trading system which can conceal the author's information safely in digital content in order to block illegal distribution of digital content. ARIA encryption algorithm is used to protect the concealed information of author in digital content and it is a help to track the illegal traders by doing fingerprinting of buyer information to digital content and managing the transaction information. The technical support for copyright dispute is to allow by providing the capability to verify illegal edit to original digital contents.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.193-200
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• 2018

Recently, there are high expectations of a society benefitting from a digital sharing economy. However, to establish a digital sharing economy, one needs to first create a reliable social structure. Transparency is recognized as the most important measure of value in not just politics or economics, but also in all domains of our lives. Although all nations strive to create "societies based on credit and trust," in truth, rigidity, irregularity, corruption, and inefficiency are widespread in all aspects of society. Thus, there is a growing interest in blockchain technology, also called the "second Internet revolution," seeking trust in digital environments, although it is difficult to obtain trust in such environments. However, the principles and methods of evaluating blockchain technologies are still unclear and not standardized. This study addresses the evaluation indexes such as transaction per second, maximum data size per one transaction, accuracy and blockchain technology application methods in the digital sharing economy and suggest ways to safely vitalize a blockchain-based digital sharing economy.

• Journal of Korea Multimedia Society
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• v.13 no.12
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• pp.1767-1777
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• 2010

In digital TV broadcasting, such as terrestrial, cable, satellite, and IPTV, the head-end of digital TV broadcasting has a more complicated transmission structure than that of analog TV broadcasting. Furthermore, digital TV broadcasting has a feature that supports multiplex models, such as Multiple Program Transport Stream (MPTS). Therefore, the purpose of our work was to design and examine a more efficient new system of emergency alert message transmission to support the digital TV broadcasting environments. Digital TV broadcasting is the IP generation or RF transmission of 8-VSB, QAM, and QPSK modulated through a multiplexer or re-multiplexer multiplexed stream as a MPEG-2 Transport Stream after content encoding. The new system proposed in this paper transmits an emergency alert message without scrambling after replacing the PID and payload of the -packet with the message prototype in the TS stream from the multiplexer. If we need to transmit an emergency alert message under digital TV broadcasting services, then the receiver first checks the PID of each packet in the TS stream for the emergency alert message. Next, if a packet is determined to be an emergency alert message, then the set-top box displays the message on the TV screen using its function of On Screen Display, or the PC based software displays the message on the monitor screen using its function of overlay with user interface if the packet is found to be an emergency alert message. We have designed an emergency alert message protocol and a system model. By experiments and analysis of the system, we concluded that the system achieved efficiency and the ability to send and receive emergency alert messages using the system under different digital TV broadcasting service environments.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.41.2-41.2
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• 2012

It has been suggested that merging plays an important role in the formation and the evolution of early-type galaxies (ETGs). Optical-NIR color gradients of ETGs in high density environments are found to be less steep than those of ETGs in low density environments, hinting frequent merger activities in ETGs in high density environments. In order to examine if the flat color gradients are the result of dry mergers, we studied the relations between merging features, luminosities, environments and color gradients of 196 low redshift ETGs selected from Sloan Digital Sky Survey (SDSS) Stripe82. Near Infrared (NIR) images are taken from UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). Color (r-K) gradients of ETGs with tidal features are a little flatter than relaxed ETGs, but not significant. We found that massive (> 10^11.3 solar masses) ETGs have -40% less scattered color gradients than less massive ETGs. The less scattered color gradients of massive ETGs could be evidence of dry merger processes in the evolution of massive ETGs. We found no relation between color gradients of ETGs and their environments.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.2
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• pp.48.1-48.1
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• 2007

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2000.05a
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• pp.323-342
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• 2000

• Architectural research
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• v.10 no.2
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• pp.11-20
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• 2008

Designing environments for the elderly includes studying changes in the elderly themselves, changes in their environment, and changes in the intercommunication between the elderly and their environment. The purpose of this study is to provide guidelines for a ubiquitous environment in which seniors can "age in place," using an environment-behavioral approach. 305 subjects aged 45 to 78 take part in the survey research. Temporal sequence (age groups) and behavior (daily activities) are considered as the significant variables to design digital services for the elderly in the perspective of an environment-behavioral approach. Several conclusions can be made. (1) The characteristics of subjects in the over-65 age group shows that they manage an independent lifestyle even if they realize some body functions deteriorate as they age. (2) Over-65 age group is more engaged in healthcare and pastime activities. The male subjects of it are most inactive. (3) The IDA (importance of daily activities) and FDA (frequency of daily activities) are classified by five to six factors in each group. The IDA and FDA of the group aged over 65 differ from other age groups. (4) Five affordance dimensions of digital services for the elderly are proposed: Healthcare, Domesticity, Mobility & Security, Network, and Recreation & Pastime. These affordance dimensions will help research groups or companies design ubiquitous environments to enhance the quality of life of seniors.

• ETRI Journal
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• v.27 no.2
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• pp.153-165
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• 2005

The main purpose of a spatial audio system is to give a listener the same impression as if he/she were present in a recorded environment. A dummy head microphone is generally used for such purposes. Because of its human-like shape, we can obtain good spatial sound images. However, its shape is a restriction on its public use and it is difficult to convert a 2-channel recording into multi-channel signals for an efficient rendering over a multi-speaker arrangement. In order to solve the problems mentioned above, a spatial audio system is proposed that uses multiple microphones on a rigid sphere. The system has five microphones placed on special points of the rigid sphere, and it generates audio signals for headphone, stereo, stereo dipole, 4-channel, and 5-channel reproduction environments. Subjective localization experiments show that front/back confusion, which is a common limitation of spatial audio systems using the dummy head microphone, can be reduced dramatically in 4-channel and 5-channel reproduction environments and can be reduced slightly in a headphone reproduction.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.475-479
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• 2005

Such changes that the digital paradigm brought propels a change of the value system itself in the existing society so that a way of thinking that differentiates oneself from others is getting much stronger. As public interests are higher in the image production on the internet, such authoring environments as development of related technologies, expansibility of information, and systematization of available information continue to change. Therefore, a variety of unique image presentations that fit to the changed environments are necessary and an expression method is indispensable for such image production. It suggests digital image application methods and examples that contain not just simple image distortion or variation but intrinsic significance. It is believed that it will be of good use to produce a variety of unique and innate digital images in the end.