• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.90-97
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• 2017

Nowadays, the most of commercial buildings are build-out with complex architecture and decorated with more complicated interiors of buildings so establishing intelligible escape routes becomes an important case of fire or other emergency in a limited time. The commercial buildings are already equipped with multiple exit signs and these exit signs may create confusion and leads the people into different directions under emergency. This can jeopardize the emergency situation into a chaotic state, especially in a complex layout buildings. There are many research focused on implementing different approached to improve the exit sign system with better visual navigating effects, such as the use of laser beams, the combination of audio and video cues, etc. However the digital signage system based emergency exit sign management is one of the best solution to guide people under emergency situations to escape. This research paper, propose an intelligent evacuation route GUIDE that uses the combination centralized Wireless Sensor Networks (WSN) and digital signage for people safety and avoids dangers from emergency conditions. This proposed system applies WSN to detect the environment condition in the building and uses an evacuation algorithm to estimate the safe route to escape using the sensor information and then activates the signage system to display the safe evacuation route instruction GUIDE according to the location the signage system is installed. This paper presented the prototype of the proposed signage system and execution time to find the route with future research directions. The proposed system provides a natural intelligent evacuation route interface for self or remote operation in facility management to efficiently GUIDE people to the safe exit under emergency conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.318-325
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• 2008

HomePlug AV(HPAV) is the standard for distribution of Audio/video content as well as data within the home by using the power line. It uses a hybrid access mechanism that combines TDMA with CSMA/CA for MAC technology. The CSMA/CA protocol in HPAV has two main control blobs that can be used for access control: contention window(CW) size and deferral counter(DC). In this paper, we extensively investigate the impacts of CW and DC on performance through simulations, and propose an adaptive mechanism that adjusts the CW size to enhance the throughput in HPAV MAC. We find that the CW size is more influential on performance than the DC. Therefore, to make controlling the network easier, our proposal uses a default value of DC and adjusts the CW size. Our scheme simply increases or decreases the CW size if the network is too busy or too idle, respectively, We compare the performance of our proposal with those of the standard and other competitive schemes in terms of throughput and fairness. Our simulation and analysis results show that our adaptive CW mechanism performs very well under various scenarios.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.312-333
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• 2005

SIP(Session Initiation Protocol) has been proposed for session control protocol of Internet multimedia communication system like VoIP(Voice over IP). SIP has complicated session control steps to support various kinds of audio and video formats and to assure service quality of real time data communication. Up until now, existing protocol analyzers can not provide such detailed information of SIP based communication system. In this paper, therefore, we propose a new protocol analyzer as a tool that can analyze and diagnose SIP based multimedia communication system throughout the session initiation, data exchange and session change steps. The propose traffic analyzer, which is called STAT(SIP based Traffic Analysis Tool), Is implemented on Winder's environment so that it is generally usable and extensible. Since STAT analyze low level packets captured via Ethernet broadcasting property, it is able to provide session status and real time traffic monitoring information without any affection to the communication system. The STAT which is implemented in this paper. therefore, is expected to be a useful tool for developing and managing of a SIP based multimedia communication system.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2662-2670
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• 1997

High speed network makes possible to transfer not only the test data but also multimedia data such as audio, image, and moving pictures and etc. In a multimedia applications, as a multimedia storage system, it is necessary to use a disk array to store and retrieve data by real time. It is important feature to various disk array parameters as a storage system on a real VOD system, such as configuration method of each disks and allocation method of multimedia data. In this paper, various parameters for the disk array are decided to be used for the video-on-demand system application by simulations in two ways. The real and simulation measurement are compared and analyzed on the performance. Simulation results shows that RAID level 5 and 256KB as striping unit and 185KB as data requests size per seconds are suitable parameter for the disk array architecture which provides MPEG-1 files with a rate of 1.5Mbps in two measurements of real and simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.227-229
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• 2019

Currently, people use game engines which is consist of essential elements(Graphic engine, Physics engine, Audio engine, UI system, Gameplay frameworks, etc) to develop video. This game engine is used for its own development, but usually it is used by renting a commercial engine. To be able to use such a game engine requires a lot of theoretical and functional education, but in a limited period of university education, it is impossible to deal with various game engines in game art colleges, not general engineering universities. This paper will compare and analyze the characteristics, and merits and demerits of these two kinds of Game engines (Unity and Unreal engine), and showed the result of analyses about the fact that educating which of the above 2 Game engines are helpful and beneficial for the students for the efficient education in the Art college where should teach much in the limited time.

• Journal of Korean Elementary Science Education
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• v.41 no.3
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• pp.569-591
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• 2022

This study aims to investigate the educational effects of the visualization of heat conduction using a thermal imaging camera on elementary school students through small group activities. It endeavors to explain the reason for why metal feels cold. The scholars conducted in-depth interviews before and after learning the unit "Temperature and Heat" for four students in fifth grade in Seoul. Recorded video and audio materials of the activities, their outputs, and journals of scholars were collected, reviewed, and analyzed. The result demonstrated that visualizing heat conduction using the thermal imaging camera aroused curiosity and provided an opportunity for sophisticated observation and integrated thinking. In addition, the visualization of the heat conduction phenomenon was used as the basis for interpretation and rebuttal for active communication during the small group activities of the students. Consequently, the students changed their non-scientific beliefs, refined their knowledge, and developed their mental models through a small group discussion based on a thermal image video.

• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.169-181
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• 1997

In this paper, we propose and discuss about image enhancement techniques for MPEG-4. which represents very low bit-rate, content-based. and object-based hierarchical audio-visual coding standard. The proposed enhancement technique removes undesired artifacts arising in the compression procedure and increase resolution in both spatial and temporal domains. In order to remove undesired artifacts. we divide the MPEG-4 video algorithm in two parts: MPEG-2 like part and the new part. For removing artifacts caused by the first part. we adopt the conventional blocking artifacts algorithm developed for MPEG-2. On the other hand for removing artifacts caused by the second part. we provide a new degradation model. and propose the corresponding image restoration method. For increasing resolution of the MPEG-4 images, we propose a general framework of multichannel image interpolation process. which includes both spatial and temporal interpolations. As the MPEG-4 standard is under development. various sophisticated techniques are considered. but research on image enhancement techniques is relatively underestimated. By this reason. additional image enhancement techniques will become very important issue in realization phase of MPEG-4.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3762-3774
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• 2000

The advances of computer hardware and information processing technologies raise the needs of multimedia information retrieval systems. Up to date. multimedia information systems have been developed for text information and image information. Nowadays. the multimedia information systems for video and audio information. especially for musical information have been grown up more and more. In recent music information retrieval systems. not only the information retrieval based on meta-information such like composer and title but also the content-based information retrieval is supported. The content-based information retrieval in music information retrieval systems utilize the similarity value between the user query and the music information stored in music database. In tbis paper. hence. we developed a similarity computation algorithm in which the pitches and lengths of each corresponding pair of notes are used as the fundamental factors for similarity computation between musical information. We also make an experiment of the proposed algorithm to validate its appropriateness. From the experimental results. the proposed similarity computation algorithm is shown to be able to correctly check whether two music files are analogous to each other or not based on melodies.

• Journal of The Korean Association For Science Education
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• v.20 no.3
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• pp.353-363
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• 2000

In this study, discourse patterns of four peer small groups in learning science concepts were examined. Verbal interactions during small group discussions were audio- and video-taped, transcribed, and analyzed. Three coding frameworks for the levels of turns, interaction units, and episodes were developed. In the analyses of turns, no clear relationships between students' prior achievements and contributions to knowledge building processes were found. Partly participating modes and symmetrical interaction modes were dominant in the analyses of interaction units to suggest that some students did not participate actively in small group discussions and that students' verbal interactions were superficial. The analyses of episodes also indicated that agreeing and/or partial elaborating on group members' ideas were the most frequent patterns and dialectical exchanges were rare in small group discussion.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.3011-3018
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• 2000

On ATM networks, ABR services are provided using the remained bandwidth after allocating CBR and VBR traffic. Realtime services such as transmitting audio or video data may be provided using CBR and VBR which have a constrained transmission delay, but in these cases, the communications bandwidth may be wasted. This paper proposes an efficient bandwidth allocation algorithm to transfer real-time data using ABR service. The proposed algorithm guarantees MCR and allocates bandwidth to each connection proportional to its MCR. The proposed algorithm divides the connections in two groups - a satisfied state group and a bottlenecked state group - and enhances bandwidth utilization by allowing the remained bandwidth after allocating the connections in the satisfied state to be allocated to the connections in the bottlenecked state. Our algorithm uses a Queue control function proposed by Ghani[5] to keep the Queue length within some boundary, which makes the transmission delay constant. We simulate and compare the performance of the proposed algorithm with that of the algorithms proposed by ATM Forum[1] and Kalampoukas[2].