• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.96-100
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• 2007

오늘날 GUI가 소프트웨어의 성공에 중요한 영향을 미침으로써 GUI에 대한 테스트가 요구된다. 반면에 소프트웨어의 GUI 테스트는 많은 노력과 시간이 소비된다. 이러한 자원의 소비를 줄이기 위해 GUI 테스트를 자동으로 수행하는 것이 필요하다. 본 논문에서는 GUI 자동 테스트를 수행하기 위해 극복해야 할 문제와 GUI 자동 테스트에 적용되는 기술에 대해 논하고, Record-Playback 기술을 이용하여 GUI 테스트 케이스 자동 생성 방법을 제시한다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1749-1755
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• 1999

The MPEG is the standard of coding moving pictures, and MPEG-1 and MPEG-2 are widely in use. And as the performance of CPU has improved, it is now possible to implement MPEG-1 in software only. This paper introduces the techniques of developing MPEG-1 playback system in software without using hardware on Windows 95 operating system. The implemented MPEG-1 playback system shows an acceptable performance.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.64-70
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• 2019

Video files of video devices such as black box and CCTV may be damaged due to repetitive file read / write and physical environment factors. Even though there are available parts of video information, it may happen that playback can't be performed due to damage of some information. To playback the remaining video information normally, it is necessary to recover damaged areas of the files. For this, it is necessary to accurately check the damage range of the files. In this paper, we propose the design and implementation of a tool which detects damaged areas of a video file and recovers the usable area of the file to playback. The proposed tool can analyze and recover without additional information by analyzing common information of video container format and can check detailed damaged ranges with chunks. It is possible to perform recovery just only with the target file and reference file without any other information such as codec specification.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.249-252
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• 2001

본 연구에서는 실영상의 재생 속도를 가변적으로 제어하여 인터렉티브한 환경을 제공할 수 있는 소프트웨어를 개발하고자 하였다. 시청각 정보로 이루어진 동영상에서 시각 정보에 관한 정보만을 추출하는 필터부, Decoder Filter로부터 Upstream된 Stream의 Time Stamp를 변경시키는 변환 필터의 제작 및 Microsoft DirectShow Component를 이용한 영상의 가변적 속도 제어 프로그램으로 이루어진다. 본 소프트웨어의 사용 결과 실영상을 최소 1/8배속에서 최대 5배속사이의 배속을 임의로 제어할 수 있었으며, 영상이 끊기는 현상 없이 부드럽게 재생 되었다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.303-305
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• 1998

MPGE(Moving Picture Expert Group)은 디지털 동영상 압축 부호화의 표준으로 자리잡고 있으며 MPEG-1에 이어 현재는 MPEG-2가 상용화되어 있는 실정이다. 복잡한 압축 기법의 적용으로 이를 재생하기 위해서는 전용의 하드웨어가 필요했지만 CPU의 성능이 향상됨에 따라 소프트웨어적으로 구현이 가능하게 되었다. 본 논문에서는 Software MPEG-1 Playback System에서 가장 큰 문제가 되는 Audio와 Video간의 동기화에 관한 기법을 제시한다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.397-399
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• 2001

프록시 서버는 점차 다양해지고 있는 클라이언트의 이질성(heteroginiety)과 이에 따른 서버와 네트워크의 과부하를 해결하기 위한 방법으로 제시되고 있다. 본 연구에서는 분산된 프록시 서버 환경에서 주어진 프록시들의 부하 균형을 위하여 각 비디오 객체의 계층(layer) 들을 서로 다른 프록시에 분리하여 저장하였다가 필요시 전송함으로서 네트워크 환경에서 특정 프록시 서버로의 집중과 혼잡성을 줄이도록 한다. 이로서 적응적인 화질(Quality Adaptation)을 보장하기 위한 계층적 코딩(layered coding) 스트리밍 서비스를 보다 효율적으로 제공할 수 있다.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.2
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• pp.103-109
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• 2020

This paper finds solutions for using ZigBee in wireless networked control system (WNCS). The round trip time delay and packet loss rate of the WNCS are measured. On the basis of these measured data, a playback buffer is used to solve the variable time delay in WNCS, and a Smith predictor is introduced to compensate for the time delay. The WNCS was able to be actually constructed to perform DC motor position control with 40 Hz sampling frequency.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1102-1104
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• 2003

KOMPSAT-2 provides two different imaging methods, direct imaging and playback imaging. For playback imaging operation KOMPSAT-2 has a storage device called DCSU (Data Compression & Storage Unit) to hold images taken before. Compression function is necessary to save memory space and data transmission time to ground station. There are several parameters for compression like compression ratio. Due to DCSU architectural characteristics and KOMPSAT-2 operational limitations, there are some restrictions on selecting compression parameters. This paper will provide selecting guides on compression parameters.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.661-670
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• 2005

According as services that offer multimedia streams are activated on the Internet, users who use these services we increased extremely. As a result of this, the increase of network traffic was occurred. Also it caused the problems such as the discontinuous playback in case of the s#ream playback and the asynchronization between a video and an audio. To solve these problems, it needs a method that guarantee the stable playback of media streams and a method of media transfer that can interact between a service user and media. Existing related researches has achieved the synchronization through various methods, but did not shown the results of satisfaction in the aspect of interaction. In this paper, we inserted the interactive objects in each media file, designed functions that these objects can use each other's information, and solved the interaction and the synchronization between a video and an audio. Also, we solved the discontinuous playback of a stream by the insufficiency of network bandwidth through using variable buffers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.3 s.345
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• pp.111-117
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• 2006

Developing a home network and a ubiquitous infrastructure requires various communication techniques and devices with more advanced hardware. With this development, increasing realtime access to multimedia data results in rapid degradation of qualify for multimedia playback. This paper presents a traffic allocation technique based on MPP(Media Preference for Presentation) that can steadily maintain multimedia playback quality by adaptively allocating streaming traffic requested from clients with different playback performances. Media preference is defined in accordance with content popularity and playback performance of client devices. Through experiments when requested stream data exceeds processing ability of a midea server, the proposed allocation technique shows 10% quality improvement comparing to the system without applying the proposed allocation technique.