• The Journal of Korean Association of Computer Education
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• v.7 no.6
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• pp.69-76
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• 2004

E-learning is the application of e-business technology and services to teaching and learning. It use of new multimedia technologies and Internet to improved the quality of learning by facilitating access to remote resources and services. In this paper, we show a web-based test system, which is carefully designed and implemented based on the real TOEFL CBT. The system consists of a contents delivery mechanism, computer-adaptive test algorithm, and review engine. In this papepr, we describe design and implementing issues of web-based test systems.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.1-8
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• 2005

E-learning is the application of e-business technology and services to teaching and learning. It use of new multimedia technologies and Internet to improved the qualify of learning by facilitating access to remote resources and services. In this paper, we show a computer-based test system, which is carefully designed and implemented. The system consists of a contents delivery mechanism, computer-adaptive test algorithm, and review engine. In this papepr, we describe what are points to be considered when design and implementing a computer-based test system. In addition, this paper shows how to control the bias value for computer-adaptive algorithm using real data.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.112-121
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• 2005

평가는 교수와 함께 교육 목표를 이루는데 있어 핵심적인 역할을 한다. 그렇지만 평가는 교수법의 발전 속도에 비교하면 상당히 느릴 뿐만 아니라, 교사는 물론 학생들에게 부정적으로 비추어지고 있다. 본 논문에서는 시험이 학생들을 동기화시킬 뿐만 아니라 그 자체로 중요한 학습 경험임을 강조하면서, 학습을 위한 평가를 활성화시키기 위해 테크놀러지를 이용한 평가 방식들을 소개하였다. 개발을 물론 어느 정도 연구가 이루어진 테크놀러지를 활용한 평가 기법을, 수행평가와 선다형의 개선안으로 대별하였다. 수행평가를 위한 기법에서는 논술채점, 지식 지도 제작법, 그리고 학습자 모형을 이용한 평가기법이, 선다형의 개선안으로 적응형 컴퓨터화 검사, 다중평가 및 변형선다형 방식이 각각 상술되었다. 결론에서는 평가를 통한 교육 효과를 극대화하기 위해서는, 교사는 물론 학생들의 평가에 대한 태도 변화 교육과 실제 교육 현장에서 쉽게 활용될 수 있는 컴퓨터를 이용한 평가기법의 개발과 보급의 중요성이 강조되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1518-1531
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• 1999

The reconstructed images from highly compressed MPEG or H.263 data have noticeable image degradations, such as blocking artifacts near the block boundaries, corner outliers at cross points of blocks, and ringing noise near image edges, because the MPEG or H.263 quantizes the transformed coefficients of 8$\times$8 pixel blocks. A post-processing algorithm has been proposed by authors to reduce quantization effects, such as blocking artifacts, corner outliers, and ringing noise, in MPEG-decompressed images. Our signal-adaptive post-processing algorithm reduces the quantization effects adaptively by using both spatial frequency and temporal information extracted from the compressed data. The blocking artifacts are reduced by one-dimensional (1-D) horizontal and vertical low pass filtering (LPF), and the ringing noise is reduced by two-dimensional (2-D) signal-adaptive filtering (SAF). A comparison study of the subjective quality evaluation using modified single stimulus method (MSSM), the objective quality evaluation (PSNR) and the computation complexity analysis between the signal-adaptive post-processing algorithm and the MPEG-4 VM (Verification Model) post-processing algorithm is performed by computer simulation with several MPEG-4 image sequences. According to the comparison study, the subjective image qualities of both algorithms are similar, whereas the PSNR and the comparison complexity analysis of the signal-adaptive post-processing algorithm shows better performance than the VM post-processing algorithm.

• Journal of Broadcast Engineering
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• v.27 no.2
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• pp.216-227
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• 2022

The MPEG-I (Immersive) group is working on a standardization project for immersive video that provides 6 degrees of freedom (6DoF). The MPEG Immersion Video (MIV) standard technology is intended to provide limited 6DoF based on depth map-based image rendering (DIBR) technique. Many efficient coding methods have been suggested for MIV, but efficient transmission strategies have received little attention in MPEG-I. This paper proposes group-based adaptive rendering method for immersive video streaming. Each group can be transmitted independently using group-based encoding, enabling adaptive transmission depending on the user's viewport. In the rendering process, the proposed method derives weights of group for view synthesis and allocate high quality bitstream according to a given viewport. The proposed method is implemented through the Test Model for Immersive Video (TMIV) test model. The proposed method demonstrates 17.0% Bjontegaard-delta rate (BD-rate) savings on the peak signalto-noise ratio (PSNR) and 14.6% on the Immersive Video PSNR(IV-PSNR) in terms of various end-to-end evaluation metrics in the experiment.