• Journal of KIISE:Software and Applications
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• v.37 no.6
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• pp.417-429
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• 2010

Reversible watermarking inserts watermark into digital media in such a way that visual transparency is preserved and then enables to restore the original media from the marked one without any loss of media quality. This watermarking can be applied to quality-sensitive imaging such as medical imaging, military imaging, remote-sensing imaging, and precious artwork, where the original media should be preserved during image processing and analysis. In this paper, a reversible image watermarking technique that embeds message bits by modifying the differential histogram of adjacent pixels is presented. In order to satisfy both high embedding capacity and visual quality, the proposed technique exploits the fact that adjacent pixels in the image have highly spatial correlation. Also, we prevent overflow/underflow problem and salt-and-pepper artifacts by employing a predicted error compensation scheme. Through experiments using various test images, we prove that the presented technique provides perfect reversibility and high embedding capacity, while maintaining the induced-distortion low.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.53-64
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• 2014

The purpose of the study is to develop a scale for measuring learning outcomes in the distance teacher training programs. In order to develop the measurement instrument, the forty-four items were developed based on the literature review and ten experts' review. For data collection, a web-based survey was conducted among teachers taking a distance teacher training program at National Education Training Institute. With the data of 205 sample size from the first survey, the Exploratory Factor Analysis was conducted and seven factors were identified. In order to validate the test, the Confirmatory Factor Analysis was performed with 293 respondents from the second survey. In conclusion, this study reports the reliability and validity of a scale for learning outcomes in distance teacher training programs consisting of seven factors with 34 items; 1) system quality, 2) content quality, 3) service quality, 4) use, 5) benefit, 6) satisfaction, 7) transfer.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.467-473
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• 2014

Adaptive learning system means a system that provides adaptively learning materials according to the learning needs of learners. It consists of expert model, instructional model and student model. Expert model is that stores information which is to be taught. Student model stores the data of learning history and learning information of students. Instructional model provides necessary learning materials for actual leaners. This paper has constructed student model through learner's profile information and instructional model through dynamic scenario construction. After that, We have developed adaptively to provide learning to learners by constructing suitable dynamic scenario based on learners profile information. In the end, satisfaction result about this system showed a high degree of satisfaction and 88%.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.2
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• pp.181-200
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• 2011

This study purposed to evaluate a youth reading promotion program that is designed and operated by the National Library for Children & Young Adults. The study specifically assessed the '1318 Bookworm Program' by conducting an in-depth survey and a focus group interview for school librarians who had participated in the program between 2007 and 2010. According to the study findings, the program participants were highly satisfied with the program outcomes. The librarians believed that the program brought positive effects on the cognitive, emotional, and social developments of the participated teens. Among the 1318 program operation process, namely designing, planning, and implementation, both planning and implementation processes were the determining factors for the outcome satisfaction. Finally, study participants expressed the needs for increasing the number of the certified professional school librarians active in the field, expanded organization structure, and further research on youth reading promotion programs in order to facilitate the program support and to enhance its efficiency. They also suggested diversified program contents development and the dissemination of manuals for youth reading promotion programs.

• Journal of Engineering Education Research
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• v.14 no.1
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• pp.3-10
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• 2011

The purpose of this study is to analyze the effectiveness of applying e-learning in industrial technology practical retraining. We have conducted a questionnaire survey for 177 subjects in 23 courses of four types of industry. Also, we have performed focus group interviews to analyze the problem and the reason for taking e-learning classes. A satisfaction measurements of the contents area(average 3.78 out of 5.0) and system area(average 3.70) were relatively high. However, the satisfaction measurement of the management area(average 3.0) was relatively low. The satisfaction measurement of learning area(average 3.68) was relatively high, but that of the behavior area(average 3.51) was on a normal level. In conclusion, an application of e-learning showed the effect on extending educational chances and spreading the technology in highly technological fields. We suggest that e-learning should be consistently and specifically expanded.

• Journal of Information Management
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• v.41 no.3
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• pp.85-104
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• 2010

This study tries to survey general behaviors of the users and their's perceptions on the service quality, with the staff members' expectations, of the Information Commons in the National Digital Library of Korea. 'Computer Cluster,' 'User guide service' and 'Internet information' are most used and general facilities, services, and contents are most satisfied. The comparative analysis shows that the customers' perceptions of overall satisfaction, customer loyalty, and service quality and overall satisfaction of each three primary dimensions(library staff, resources and services, facility and physical environment) are higher than those of staff members' expectations.

• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.742-751
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• 2011

This paper presents a robust 3D model hashing dependent on key and parameter by using heat kernel signature (HKS), which is special shape feature descriptor, In the proposed hashing, we calculate HKS coefficients of local and global time scales from eigenvalue and eigenvector of Mesh Laplace operator and cluster pairs of HKS coefficients to 2D square cells and calculate feature coefficients by the distance weights of pairs of HKS coefficients on each cell. Then we generate the binary hash through binarizing the intermediate hash that is the combination of the feature coefficients and the random coefficients. In our experiment, we evaluated the robustness against geometrical and topological attacks and the uniqueness of key and model and also evaluated the model space by estimating the attack intensity that can authenticate 3D model. Experimental results verified that the proposed scheme has more the improved performance than the conventional hashing on the robustness, uniqueness, model space.

• Journal of Practical Engineering Education
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• v.7 no.1
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• pp.25-30
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• 2015

Virtual reality is a combination of various studies, such as programming, simulation, and computer graphics. This type of new cultural paradigm requires novel concept of contents development and information exchange. This research uses 3D virtual reality technology in new equipment called I-Bench Mobile which let user to interact with the equipment for completing furniture disposition task. The simulation is manufactured in 3D with application of physics, and the ultimate goal of it is to increase customers' satisfaction by allowing them to enjoy snap shot function for arranging furniture at exact desired place. This research requires not only coding techniques but also educating process in both engineering and art, such as computer science, media art design, and visual communication; therefore, the development of software by facilitating Virtual/Augmented Reality technology in this research is a good example of fusion IT technique education.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.688-693
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• 2014

With the advent of ubiquitous environments, the smart phone has come into wide use and the demand for various content increases. Thus, in order to efficiently utilize limited resources cognitive radio technology is regarded as a possible solution. Besides spectrum sensing or access schemes, the provision of VoIP traffic service for secondary users with limited spectrum resources is a very important issue. In this paper, a resource allocation and control system for VoIP QoS provision in cognitive radio networks is proposed. Firstly, as the system model, the time structure of the network is addressed and, according to the structure, a bandwidth broker is proposed. In addition, based on available bandwidth estimated by the bandwidth broker, a connection admission control for secondary users is developed. It is demonstrated that the provision of VoIP QoS is greatly affected by channel utilization, the number of channels, and the length of timeslot.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1347-1358
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• 2008

A blind video watermarking scheme for providing safety, authenticity, and copyright protection is proposed in this paper, which is robust to MPEG-4 SVC and multimedia transcoding. In proposed method, embedding and detecting of watermark is performed based on base layer with considering spatial SVC. To be robust from temporal SVC, our method embeds repeatedly a permutated character with ordering number per one frame. Also for robustness from multimedia transcoding and FGS, the method is embedded watermark in low middle frequency of each frame adaptively based on DCT in ROI. Through experimental results, invisibility of the watermark is confirmed and robustness of the watermark against the spatial SVC, temporal SVC, FGS and video transcoding between MPEG-2 and MPEG-4 SVC is also verified.