• Journal of Korea Multimedia Society
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• v.14 no.11
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• pp.1431-1437
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• 2011

This paper proposes a novel watermarking algorithm that protects digital copyrights and is robust to attacks. Watermarks are embedded in the subband including the significant part of the signal such as a pitch. Generally, the subband containing the pitch has the biggest energy. In order to find this subband, wavelet packet transform is used to decompose the subbands and their energy are calculated. The signal of the selected subbands is transformed in frequency domain using FFT. The watermarks are embedded using QIM for samples higher than a certain threshold. The blind detection uses the Euclidean distance. The proposed method shows less than 5% BER in the audio watermark benchmarking.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.424-432
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• 2016

World's leading countries are developing next generation digital broadcasting system specifications to support UHDTV (ultra-high definition television) contents and other various services. In order to maximize the transmission capacity by using the bandwidth efficiently, most broadcasting systems adopt MIMO-OFDM. In distributed-MIMO systems, multiple transmit antennas are spatially separated and therefore result in multiple timing offsets. To overcome this problem, this paper proposes a technique using a null symbol to detect each individual signal from distributed transmit antennas. By inserting null symbols before preambles, the receiver can distinguish the signals between each transmit antennas and perform frame synchronization. When the reception time difference is shorter than 500 samples, the proposed method outperforms the conventional method.

• The KIPS Transactions:PartB
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• v.17B no.4
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• pp.275-286
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• 2010

Reversible watermarking which can preserve the original quality of the digital contents and protect the copyright has been studied actively. Especially, in medical, military, and art fields, the need for reversible watermarking is increasing. This paper proposes a high-capacity reversible watermarking through predicted error expansion and error estimation compensation. Watermark is embedded by expanding the difference histogram between the original value and the predicted value. Differently from previous methods calculating the difference between adjacent pixels, the presented method calculates the difference between the original value and the predicted value, and that increases the number of the histogram value, where the watermark is embedded. As a result, the high capacity is achieved. The inserted watermark is extracted by restoring the histogram between the original value and the predicted value. To prove the performance, the presented algorithm is compared with other previous methods on various test images. The result supports that the presented algorithm has a perfect reversibility, a high image quality, and a high capacity.

• Informatization Policy
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• v.20 no.4
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• pp.3-22
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• 2013

This study analyzed the research trends and methodologies through meta analysis method on the issues of ICT policy and e-government in Korean major journals and proceedings including Korean Association of Public Administration (KAPA), Korean Association of Policy Studies (KAPS), and Korean Journal of Information Policy of NIA (National Information Agency). The results showed that methodology has changed from explorative study with conceptualization to experimental study with theoretical model and cases. Qualitative approaches including case studies and description with policy implications were employed more as analyses tools. In terms of contents, system effectiveness and e-governance issues prevailed in the early 2000s, and since then, it has changed into ICT-based social changes and looking for generalization of theories including e-democracy, e-service, e-participation, digital divide, and post-information society. Now we are facing another ICT revolution of social network via web3.0 and gov3.0 and it is time to open a new theoretical debate, deconstruction of discourse, and collaborative perspective among different disciplines.

• The Journal of the Acoustical Society of Korea
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• v.22 no.7
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• pp.612-621
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• 2003

As the use of MP3 audio compression increased, the demand for the insertion of additive data about copyright or information on music contents has been groved and the related research has been progressed actively. When an additive data is inserted into MP3 bitstream, it should not to happen any distortion of music quality or the change of file size, due to the modification of MP3 bitstream structure. In our study, to make these conditions satisfied, we inserted some additive data to bitstream by modifying some bits of linbits among the quantized integer coefficients having big values. At this time, we consider the characteristics of linbits and their distributions. As a result of subjective sound quality test through MOS test, we confirmed that the quality of MOS 4.6 can be achieved at the data insertion rate of 60 bytes/sec. Using the proposed method, it is possible to effectively insert an additive data such as copyright information or information about media itself, so that various applications like audio database management can be realized.

• Journal of The Korean Association of Information Education
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• v.9 no.4
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• pp.617-625
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• 2005

With enforcement of information usage education since 1997, teachers have been given many different types of training to improve teacher's expertise. Especially, It has established distance education centers as an attempt to construct advanced training system in digital information society to solve the problems with current attendance-based training, and then its number has increased until now, total 53 institutes are on the list at the moment (Sep.2004). In this research, it has conducted a survey and analysis on educational contents and general management state, based on the curriculum of distance training center, for making its quality improvement plan including mutual contentment of both provider and demander for elementary school teachers. Examining the survey, it is expected for providers to accommodate persistent feedback to reflect periodically changing needs and various interest. From users' perspective, they wanted varied programs to choose in many other subjects for enhancing its expertise, rather than taking classes just for evaluation.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.4
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• pp.628-641
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• 2012

This research investigates a dynamic mechanism underlying the co-evolution between network and space by applying hype-curve model, typical phenomenon which shows how new technologies and ideas initially adapted in the society. This study analysis the knowledge intensive industry of digital contents using social network analysis (SNA) in terms of structural, spatial, and temporal aspects, year of 2000, 2005, and 2010 focused on Seoul area. First of all, network and space establish 'inter-feedback' as a result of evolution and differentiation process. Second, it happen temporal 'delay' through the learning process stage of 'peak of inflated expectation' and 'trough of disillusionment.' As a result, Seoul develops with the technology commercialized-orient strategy affect government policy. This trend changes to technology-oriented development in Seoul area in the late of 2000 established 'self-organization' with geographical proximity organizations through learning process.

• Journal of the Korea Computer Graphics Society
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• v.18 no.3
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• pp.9-16
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• 2012

In this paper, we present a new method for reconstructing detailed facial expression from roughly captured data with a small number of markers. Because of the difference in the required capture resolution between the full-body capture and the facial expression capture, they hardly have been performed simultaneously. However, for generating natural animation, a simultaneous capture for body and face is essential. For this purpose, we provide a method for capturing the detailed facial expression only with a small number of markers. Our basic idea is to build a database for the facial expressions and apply the principal component analysis for reducing the dimensionality. The dimensionality reduction enables us to estimate the full data from a part of the data. We justify our method by applying it to dynamic scenes to show the viability of the method.

• Journal of Korea Game Society
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• v.10 no.6
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• pp.89-96
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• 2010

To identify characteristics of social network farm game based on smart phone platform, this study analyzed how social network play experience connects with the space of farm game. The play experience of social network farm game based on smart phone platform is mainly composed of three modules for cultivating, placing environment, extending space. This study categorized space for external perspective space, internal perspective space, symbolic design space according to space experience theory and researched play experience in these spaces. In farm game players perceive space by fixed point of view, and make their own space a standard unit for reinterpreting and rearranging modules. In this process the space played subjective role not only background to bring co-work play is essential in social network game.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.105-111
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• 2018

STEAM and S / W education in public education are effective in fostering talented people and the talents of the 4th industrial revolution era. It is necessary to expand the teachers for this purpose, to find out and apply various learning materials, and to improve education environment for fusion talent education. An open learning platform is effective in reducing private education costs and supplementing public education. Especially, it is useful for flip learning combined with classroom (off-line). In this case, teacher's role can be transformed into active teaching activities and research activities, which can speed up normalization of public education and reduce private education.In particular, the core functions of the MOOC platform for elementary education are 'creative instructional design and contents development function', 'digital teaching and learning curation', 'big data based learner customization', 'learning participation' flip learning and social Learning function.Through this study, it is expected that discussion on the introduction of MOOC for career and admission education for adolescents including elementary education will be established and the Korean youth MOOC platform will be developed and developed as a global advanced model of education democratization.