• Journal of Korea Multimedia Society
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• v.8 no.7
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• pp.1012-1021
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• 2005

This paper describes the design and implementation of an efficient multi-point multimedia conference system using IP grouping. Existing multi-point multimedia conference systems are difficult for multi-user to perform efficient cooperation due to bandwidth limitation for data transmission of video, audio and documentation. In the case that multi-user uses limited bandwidth, smooth cooperation does not accomplish due to transmission delay for the real-time transmission of image and speech data. A hybrid transfer method which is mixed with distributed and centralized methods is used for smooth cooperation, and the network bandwidth is reduced by forming multi-user conference systems of IP grouping in this paper. Also, adaptive image frame variations are used to solve bottleneck effect according to the number of users. An efficient multi-user conference system is designed to support audio quality.

• Journal of KIISE
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• v.43 no.11
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• pp.1281-1297
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• 2016

In recent years, personal videos have seen a tremendous growth due to the substantial increase in the use of smart devices and networking services in which users create and share video content easily without many restrictions. However, taking both into account would significantly improve event detection performance because videos generally have multiple modalities and the frame data in video varies at different time points. This paper proposes an event detection method. In this method, high-level features are first extracted from multiple modalities in the videos, and the features are rearranged according to time sequence. Then the association of the modalities is learned by means of DNN to produce a personal video event detector. In our proposed method, audio and image data are first synchronized and then extracted. Then, the result is input into GoogLeNet as well as Multi-Layer Perceptron (MLP) to extract high-level features. The results are then re-arranged in time sequence, and every video is processed to extract one feature each for training by means of DNN.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.559-569
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• 2007

The purpose of this case study is to analyze the characteristics of social interaction according to gender-grouping in the application of LTTS program. For this study, mixed-gender group A (one boy and three girls or one girl and three boys), mixed-gender group B (two boys and two girls) and same-gender group (4 boys or 4 girls) were formed. Social interactions during group discussions were audio-/video-taped. Social interactions between one boy and one girl in each group were analyzed. The type of social interactions were classified as cognitive and affective interactions. The boy and the girl in the same gender group tended to make suggestion actively, but sometimes they ordered peers to participate or prevented peers from participating. On the other hand, they didn't tend to make suggestion about problem-solving in mixed-gender group A, but made suggestion against peer's opinion using appropriate reasons. The frequency of affective interactions in the mixed gender group B were higher.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.378-382
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• 2001

There are some technical problems in current internet-broadcasting. The load of server rises in proportion to user connection. And the inefficient usage of network bandwidth deteriorates quality of services and doesn't transport multimedia data in real time. To overcome above problems, multicast transport technology is applied to real-time multimedia data transport. But the reliability problem is still remained. This paper provides an efficient design of internet broadcasting server. We propose an multimedia data transport algorithm using adaptive encoding by grouping users according to similar connection environment. Performance evaluations show that the mechanism decreases the load of server and improves the quality of services.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.870-880
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• 2007

The purpose of this study was to understand the change and characteristics of interactions in a heterogeneous group in scientific inquiry experiments. For this purpose, the process of students' interactions in small group activities were analyzed. This study focused on two, small heterogeneous groups of eighth graders. Students were involved in 13 scientific inquiry experiments for one year and students' interactions in each experiments were observed and recorded using video/audio and the data recorded were transcribed. The analysis of data was based on the method of making a note by looking and listening to the data repeatedly. Students' interactions in heterogeneous group changed toward that 3A (early formal operation student solved the problems by oneself and other students only listened to 3A student's explanation or copied the answer. The least able student was alienated from peers' interactions. In the meantime, new interactions of two middle level students were shaped. Educational implications of the progression of activities emphasizing interactions and the organization of grouping were drawn.

• Journal of The Korean Association For Science Education
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• v.28 no.1
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• pp.75-88
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• 2008

The purpose of this study was to understand the factors affecting interactions as well as the students' learning process in small group activities. For this purpose, the changes and characteristics of students' interactions in scientific inquiry experiments were analyzed. This study focused on 2 homogeneous small groups of eighth graders. Students were involved in 13 inquiry experiments for one year and students' interactions in each experiments were observed and recorded using video/audio and the data recorded were transcribed. The analysis of data was based on the method of making a note by looking on and listening to the data repeatedly. Changes in the interactions of the two homogeneous groups differ remarkably. In small group A, owing to the conflicts of students' emotions, learning through social interactions became to be impossible. On the other hand, the interactions in small group B became more active. It seems that this changes are affected largely by the existence of peers who are able to mediate different opinions or feelings among group members. In general, middle school students were poor at receiving peers' opinion, cared a lot about writing reports. The less able students tended to be placed at a disadvantageous position in experiment lessons emphasizing social interactions. Four factors that affected the change of interactions were identified: Is the aim of experiments the understanding or completion of report? Is there any attitude towards peers' suggestions? Is there a disposition to care about peers? Is there any peer to mediate on peers' opinions or feelings? Educational implications of the progression of activities emphasizing interactions and the organization of grouping were drawn.