• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.247-254
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• 2008

H.264 provides a good coding efficiency compared with existing video coding standards, H.263, MPEG-4, based on the use of multiple reference frame for variable block size motion estimation, quarter-pixel motion estimation and compensation, $4{\times}4$ integer DCT, rate-distortion optimization, and etc. However, many modules used to increase its performance also require H.264 to have increased complexity so that fast algorithms are to be implemented as practical approach. In this paper, among many approaches, fast mode decision algorithm by skipping variable block size motion estimation and spatial-predictive coding, which occupies most encoder complexity, is proposed. This approach takes advantages of temporal and spatial properties of fast mode selection techniques. Experimental results demonstrate that the proposed approach can save encoding time up to 65% compared with the H.264 standard while maintaining the visual perspectives.

• Journal of Information Technology Applications and Management
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• v.28 no.3
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• pp.59-75
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• 2021

This study aims to establish a foundation for autonomous driving on campus and communication of abundant university information in the HCI environment in a VR environment where college freshmen can freely travel around campus facilities. The purpose of this study is to develop a three-dimensional VR-style campus tour system to establish a media environment to provide abundant university information guidance services to freshmen in non-face-to-face situations. This study designed a three-dimensional virtual reality campus tour system to solve the problem of discontinuity in which VR360 filming space does not lead to space like reality, and to solve many problems of expertise in VR technology by constructing an integrated production environment of tour system. We aim to solve the problem of inefficiency, which requires a large amount of momentum in virtual space, by constructing a GUI that utilizes the motion of the field of view focus. The campus environment was designed as a three-dimensional virtual reality using a three-dimensional graphic design. In non-face-to-face situations, college freshmen freely transformed the HMD VR device, smartphone, FPS operation mode of the gyroscope sensor. The design elements of the three-dimensional virtual reality campus tour system were classified as ①Visualization of factual experiences, ②Continuity of space movement, ③Operation, automatic operation mode, ④Natural landscape animation, ⑤Animation according to wind direction, ⑥Actual space movement mode, ⑦Informatization of spatial understanding, ⑧GUI by experience environment, ⑨Text GUI by building, ⑩VR360, 3D360 Studio Environment, ⑪Three-dimensional virtual space coupling block module, ⑫3D360-3D Virtual Space Transmedia Zone, ⑬Transformable GUI(VR Device Dual Viewer-Gyro Sensor Full Viewer-FPS Operation Viewer) and an integrated production environment was established with each element. It is launched online (http://vautu.com/u1) by constructing a GUI for free driving mode and college information screens to adapt to college life for freshmen, and designing an environment that can be used simultaneously by current media such as PCs, Android, and iPads. Therefore, it conducted user research, held a development presentation, a forum on excellence in university innovation support projects, and applied it as a system on the website of a particular university. College freshmen will be able to experience university information directly from the web and app to the virtual reality campus environment.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.25-32
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• 2019

According to a recent KOFICE survey, K-Pop's popularity factor is divided into visual and auditory elements, and the importance of hearing elements is found. Among the various types of singers, idol groups led K-Pop and Black Pink, which topped the list of favorite K-Pop singers in 2018, was selected as the study target. In addition, Twice's music, which is similar to Black Pink's period of activity, has been set as a comparative research scope. The common features in the music of the two groups are the chorus and rhythm structure implemented around melody and Harmony rhythm, and the frequency of use of Major and Minor is greatly different. Through this method and modal interchange, K-Pop from 2016 to 2018 is analyzed. Research shows that first, more than one mode is used as a main melody. When more than one mode is used, different lines in the same line will vary depending on the functional form of the song. Second, the rhythm of the melody expressed with vocals and instruments is repeated based on a two-bar pattern. Finally, when using less chord and slowly expressing the igneous rhythms, there is a way to omit or modify the third notes that determine chord characteristics. Through this study, we can see that the usage patterns of the mode and modal interchange are divided according to the major and minor.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.2 s.302
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• pp.39-48
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• 2005

In this paper, we implement the multimedia remote control system by using existing internet service or wired online. We also provide user-friendly convenient environment with developed application program named EzPlay and PC-EPG. The multimedia remote control system consists of integrated wireless transceiver of PC and TV connected USB type and the users can easily use lots of contents because EzPlay program provides appropriate UI mode on the PC and TV screen. The unposed system can operate real-time playing, reserved video receding and data storing function using internet mesh based on signal detecting control theory. The PC-EPG system is implemented by server/client web program and the client program based on visual C++/MFC processes data storing in client computer through TCP/IP. It also provides intelligent function that constructs database according to user's preference.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4891-4896
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• 2015

In this paper planed Secret Single Message Service using MVLS(Multipurpose Visual Language System) for conceal contents to other persons that based on national institutions and private organizations report. This system is not persue to important contents like national or company's secret, but merely just decode to general and conceal SMS that using peoples at real life. This system is have an advantage that encoding to message like between lover's conversations or dislike contents to view the other persons, only can see own users that is to keep private life. Also, this system offers convenience to users that using general SMS service and only activate On-Off function for secret mode to user's needs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.12-19
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• 2004

An aerodynamic design optimization system for three-dimensional wing was developed as a part of the future MDO framework. The present design optimization system includes four modules such as geometry design, grid generation, flow solver and optimizer. All modules were based on commercial softwares and programmed to have automated execution capability in batch mode utilizing built-in script and journaling. The integration of all modules into the system was accomplished through programming using Visual Basic language. The distributed computational environment based on network communication was established to save computational time especially for time-consuming aerodynamic analyses. The distributed aerodynamic computations were performed in conjunction with the global optimization algorithm of response surface method, instead of using usual parallel computation based on domain decomposition. The application of the design system in the drag minimization problem demonstrated considerably enhanced efficiency of the design process while the final design showed reasonable results of reduced drag.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.641-651
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• 2002

Recently, many advanced video application services over the mobile wireless networks have required a transcoder which can efficiently reduce the size of compressed video bitstreams. The transcoder can be worked in either the spatial domain or the DCT domain. In this paper, we propose a new fast hybrid-type transcoder which can efficiently reduce the frame size with keeping the visual quality. The proposed scheme consists of two major processes: a transform domain process and a spatial domain process. We also propose a scheme for coding mode selection and motion vector refinement. Experimental results show that our approach can reduce the computational complexity more than any other conventional spatial-domain transcoder with keeping the visual quality.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.652-663
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• 2002

Recently, many advanced video application services over the mobile wireless networks have required a transcoder which can efficiently reduce the size of compressed video bitstreams. The transcoder can be worked in either the spatial domain or the DCT domain. In this paper, we propose a new fast hybrid-type transcoder which can efficiently reduce the frame size with keeping the visual quality. The proposed scheme consists of two major processes: a transform domain process and a spatial domain process. We also propose a scheme for coding mode selection and motion vector refinement. Experimental results show that our approach can reduce the computational complexity more than any other conventional spatial-domain transcoder with keeping the visual quality.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.4
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• pp.16-25
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• 2003

A parallel computing environment based on Windows operating system was constructed and a performance test was mode in comparison with Linux based systems. The Windows 2000 cluster was composed with servers and clients connected by Fast-ethernet, within which two sub-clusters may operates together or separately. Compaq Visual Fortran complier and two MPI libraries, MPICH.NT.1.2.2 and NT-MPICHNT.1.2 were installed as computing tools. Parallel computing performance tests were carried out using two-dimensional preconditioned Navier-Stokes code to examine the dependency on the number of processors, problem size and MPI libraries, those were compared with results from Linux clusters. Results shows that a cluster based on the user-friendly Windows operating system is also useful for the parallel computing and has good performance comparable to the previous Linux clusters.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.20-29
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• 2013

The compression of video data is intended for real-time transmission of band-limited channels. Compressed video bit-streams are very sensitive to transmission error. If we lose packets or receive them with errors during transmission, not only the current frame will be corrupted, but also the error will propagate to succeeding frames due to the spatio-temporal predictive coding structure of sequences. Error detection and concealment is a good approach to reduce the bad influence on the reconstructed visual quality. To increase concealment efficiency, we need to get some more accurate error detection algorithm. In this paper, We hide specific data into the motion vector difference of each macro-block, which is obtained from the procedure of inter prediction mode in H.264/AVC. Then, the location of errors can be detected easily by checking transmitted specific data in decoder. We verified that the proposed algorithm generates good performances in PSNR and subjective visual quality through the computer simulation by H.324M mobile simulation tool.