• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.603-612
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• 2010

Recently, with the advance of computing and networking technique, the high speed internet becomes widespread, however, it is still hard job to do streaming the media which requires high network bandwidth over the internet. Previous VoD system researches for streaming over the internet mainly proposed techniques that controls the QoS(Quality of Service) of the media in proportion to the network status. Though, this could be the solution for the service provider while the service user who wants constant QoS may not satisfy with variable QoS. In the paper, we propose greedy precedent frame transmission technique, GPFT, for guarantee of constant QoS. In GPFT, Streaming VoD server prefetches precedent frames and transmits the frame greedily by increasing the frame transmission rate while the available network bandwidth is high. The GPFT uses the prefetched precedent frames to guarantee the QoS while the available network bandwidth is low. The experiment result shows that the proposed GPFT could guarantee the constant QoS by prefetching the frames adaptively to the network bandwidth with the characteristic of video stream.

• Journal of Digital Contents Society
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• v.13 no.1
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• pp.119-127
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• 2012

In this study, it was witnessed that a variety of tests are implemented in a type of convergence of multimedia such as photos, sounds, and videos as well as letters and drawings, components of existing traditional comics as comics are digitalized and are converted to various devices. Therefore, we studied the concept of multimedia comics as a basis of this study by judging that new barometer to comics lies in convergence with such multimedia. After recognizing components of multimedia comics which are currently emerging, we categorized them into three types depending on how to use these elements. First, convergence type webtoon has a very similar format with existing vertical scrolling webtoon and has characteristics that background & effects sounds are added to emphasize the features of webtoon, or photos or videos are inserted in part, and there is no function to control these elements; Second, motion comic, a medium format between comic and animation has a characteristic that sound, video, paging are auto-played like watching animation but it keeps the format of comics within one frame; Third, interactive comic has a characteristic that effects sound, motion, and story are made by active participation of viewers. As a result of analyzing comics which having above multimedia characteristics, its implications are as followings: First, multimedia elements should be used depending on genre, age, and media; Second, high level of control technology considering the features of comic-viewers is needed. In other words, in continuously evolving media environments, comic contents being proper to targets and use purposes of viewers should be developed. For this, multimedia elements of comics should be used in order that comic-viewers can have active & interactive communication with contents.

• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.191-200
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• 1995

Although air, water, and noise pollutions have been widely recognized, electromagnetic forces (EMF) hazard has been rarely recognized as a pollution and very little studies has been done in this country. Thus, in this study electromagnetic forces radiated by various home appliances, office machines, and communication equipments were measured and so were several places radiating strong EMF such as subway stations and electric substations. Among the home appliances microwave oven radiates lots of magnetic field and microwaves, and electric mattress does strong magnetic field. In video game room strong magnetic and considerable electric fields were measured. It was observed strong magnetic field inside of electric powered train and very strong magnetic and electric fields on some platforms. Hand-phone and car-phone radiate very hazardous level of microwaves to brain and that they rapidly come into wide use. In this study data base for various electric machines and places radiating strong EMFs were constructed and could be used for future epidemiological studies.

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.261-272
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• 2014

In this study, to disseminate the Practical On-site Cooperation Model (POCoM) for practical improvement of science teaching and learning through cooperation between researcher and teacher, an in-service program has been developed, applied and evaluated. The in-service program emphasizes the following three aspects; (1) video-recording of actual science teaching has been used as a primary resource, (2) communication between teacher and researcher and among teachers have been emphasized, (3) activities have been mainly included. The in-service program has been implemented for nine hours, and 17 science teachers have been recruited as volunteers. The result shows that, by checking the agreements between raters, we found that teachers' expertise in analyzing the science class using the Korean Teaching Observation Protocol (KTOP) has improved, and we have confirmed that teachers are able to judge whether the science class has improved or not. Through the questionnaire, various highly positive responses could be obtained from teachers. And through the observation of teachers' activities during the in-service program, teachers' questions, their difficulties in doing activities, and their comments for improving the program has also been analyzed. Finally, based on the results, a list of recommendations for a more effective in-service program have been suggested. It is expected that this list can be utilized for more effective and meaningful design and implementation of in-service course.

• Korean Security Journal
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• no.24
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• pp.125-146
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• 2010

The G20 summit is the premier forum for international economic cooperation and it will be held in Seoul in November 2010. However, protests are expected during the Seoul summit, as a part of the deepening global war against capitalism. The Korean Police need to deal with these protests effectively in order to provide security to the participating leaders and make the meeting run on wheel as planned. The current study attempts to analyze the death of Ian Tomlinson who died in the context of a heavily policed protest during 2009 G20 London summit. There are number of unique features regarding this incident, such as the public scrutiny of police conduct through video footage, the police use of excessive force, and the process to hold the police to account for misconduct. This incident caused serious damages to the public's faith in the British police. Based on the analysis, this study found that during the G20 London summit British police had the problems such as the lack of the clear standards on the use of force, improper training in the use of force, poor communications with the media and protesters, inappropriate use of the close containment tactic, and the failure to display police identification. Therefore, this study suggests the inducement of peaceful protests, the adoption of a set of standards on the use of force, public order training that is more directed and more relevant to the public order challenges facing the Korean police, improvement of the communication with the media and protesters, enhancement of individual officer's accountability as public order policing strategies for G20 Seoul summit meeting. However, the most fundamental principle is that Korean police must place a high value on tolerance and winning the consent of the public.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.519-527
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• 2011

The e-Learning program is a multimedia data program consisting of texts, images, animation, audio and video. The development of an e-Learning program requires time and is a complex process, requiring cooperation and open-communication between all parties involved, particularly in the event of a problem. This study will analyze the e-Learning contents development process from the Social Negotiation Perspective. An appropriate process for the development of the program and effective decision-making guidelines for those parties involved will be recommended. Participants' viewpoints regarding program development and guidelines were studied qualitatively, while the evaluation of developed content employed both qualitative and quantitative research. The study found the following results. First, the development of an e-Learning program requires a clear goal and purpose. Second, the target group must be clearly identified. Third, all parties involved must share in the development process and its outcomes. Fourth, the party requesting the program must allocate the appropriate time and budget for the development group. Finally, the project requires a strong, capable leadership for effective decision-making.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2202-2211
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• 2006

EXT3NS is a special-purpose file system for large scale multimedia streaming servers. It is built on top of streaming acceleration hardware device called Network-Storage card. The EXT3NS file system significantly improves streaming performance by eliminating memory-to-memory copy operations, i.e. sending video/audio from disk directly to network interface with no main memory buffering. In this paper, we design and implement a buffer cache mechanism, called PMEMCACHE, for EXT3NS file system. We also propose a buffer cache replacement method called ONS for the buffer cache mechanism. The ONS algorithm outperforms other existing buffer replacement algorithms in distributed multimedia streaming environment. In EXT3NS with PMEMCACHE, operation is 33MB/sec and random read operation is 2.4MB/sec. Also, the buffer replacement ONS algorithm shows better performance by 600KB/sec than other buffer cache replacement policies. As a result PMEMCACHE and an ONS can greatly improve the performance of multimedia steaming server which should supportmultiple client requests at the same time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2712-2716
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• 2011

The development of mobile phone is growing everyday according to the change of our age. Most of all, the birth of smart phone has gotten lots of attentions. The Smart Phone has not only nalogue functions for calling and receiving but also has many multiple-service functions satisfying the contemporary digital needs. Due to the smart phone, people could access to various and plenty information simply by touching it. It was Sep. 2011 that the number of smart phone users began to be more than 15,000,000. That number stands for the turning point of digital revolution. In Korea, both of "Omnia" from Samsung and "i-phone" from Apple came into the market near the end of 2009. That time was so called the full-scale first smart-phone war, and thinking of the time, it could be named as the explosive growth of smart phones. We can predict that the smart phone will influence the real life of human beings not only the mobile phone market. In this way, the smart phone has come deeply into our life day by day. For instance, more people can be able to get the informations of their trip for their leisure and free weekends through the smart phone. Thus, our study, began with the theme of "Korean islands trip", will start in the relationship with the Application-Services, "Islands" utilizing web-pictures.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.573-586
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• 2008

The improved performance and miniaturization of computer and the improvement of wireless communication technology have enabled the emergence of many high quality services. Among them multicast services are receiving much attention and their usage is increasing due to the increase of Internet multimedia services such as video conference, multimedia stream, internet TV, etc. Security plays an important role in mobile multicast services. In this paper, we proposed a secure multicast protocol for a hierarchical micro-mobility environment. The proposed secure multicast protocol provides security services such as authentication, access control, confidentiality and integrity using mechanisms including symmetric/asymmetric key crypto-algorithms and capabilities. To provide forward/backward secrecy and scalability, we used sub-group keys based on the hierarchical micro-mobility environment. With this security services, it is possible to guard against all kinds of security attacks performed by illegal mobile nodes. Attacks executed by internal nodes can be thwarted except those attacks which delete packet or cause network resources to be wasted. We used simulator to measure the performance of proposed protocol. As a result, the simulation showed that effect of these security mechanisms on the multicast protocol was not too high.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.1-8
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• 2009

In this paper, we propose a home medical system that integrates a self-diagnosing disease classification system and a tele-consulting system by communication technology. The proposed disease classification system supports to self-diagnose the health condition based on oriental medical science using fuzzy neural network algorithm. The prepared database includes 72 different diseases and their associated symptoms based on a famous medical science book "Dong-eui-bo-gam". The proposed system extracts three most prospective diseases from user's symptoms by analyzing disease database with fuzzy neural network technology. Technically, user's symptoms are used as an input vector and the clustering algorithm based upon a fuzzy neural network is performed. The degree of fuzzy membership is computed for each probable cluster and the system infers the three most prospective diseases with their degree of membership. Such information should be sent to medical doctors via our tele-consulting system module. Finally a user can take an appropriate consultation via video images by a medical doctor. Oriental medical doctors verified the accuracy of disease diagnosing ability and the efficacy of overall system's plausibility in the real world.