• Journal of KIISE:Computing Practices and Letters
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• v.16 no.10
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• pp.975-979
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• 2010

Existing quality adaptation schemes are useful for improving network stability in a congested network, but these schemes do not guarantee the quality of experience on video streaming due to the frequent variations in playback quality for a streaming service. In this paper, we propose a network-adaptive quality adaptation scheme to guarantee the quality of experience on SVC(Scalable Video Coding) video streaming. The proposed scheme estimates the available bandwidth by bandwidth measurement scheme using media characteristic, and then smoothly adjusts the quality level of SVC video stream according to the estimated bandwidth. Through the simulation, we prove that our scheme guarantees the quality of experience for video streaming by minimizing quality variation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1618-1626
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• 2013

Virtualization service processes all operation including the data creation, storing, and disposal in a server and transmits processed data as the streaming media form. Therefore, client can use the same environment as the traditional desktop environment without considering the type of device. Virtualization service should consider not only the video quality but also the delay bounds and continuity of video playback for improving the user perceived Quality of Service(QoS) of streaming service. In this paper, we propose a network-adaptive transmission architecture that focuses on guaranteeing QoS requirements for virtualization service. In order to provide those, the proposed architecture have the transmission rate adaptation function based on available bandwidth and the content bit-rate control function based on sender buffer state. Through each function, proposed architecture guarantee the delay bounds and continuity of virtualization contents playback. The simulation results show that proposed network-adaptive transmission architecture provides a improve performance of throughput and transmission delay.

• Journal of Internet Computing and Services
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• v.11 no.4
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• pp.1-10
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• 2010

As recent fusion industry and ubiquitous technology have grown fast, network contents, which require high load, are provided in various infrastructures and facilities such as u-city and smart phones. Therefore, it is anticipated that the playback quality of multimedia compared to network loads degrades dramatically due to the drastic increment of real-time reference of conventional high load contents (eg. multimedia data). In this paper, we improved the method of the traffic assignment based on MPP which elevated the playback quality of multimedia by assigning discriminately the possible traffic of MMS with TP coefficients. When the TP coefficient which combines content preference with media preference was applied to a real-time traffic assignment scheduler, the simulation results showed that the multimedia playback stream was assigned within the possible traffic of a server. The real-time scheduling algorithm was improved by using the TP coefficient that combines the time-dependent image contents and the weighted value of media preference. It was observed from the experiment that the loss of the possible traffic decreases to 3.91% and 3.88% for three and four clients respectively.

• The Transactions of the Korea Information Processing Society
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• v.4 no.1
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• pp.107-117
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• 1997

It is use in many researches that the s/w quality evaluation evaluates the developing system or the developed system, updates the problems and selects the reusable components from source code. In this paper, we propose the objective metric functions which can evaluate the reusability of candidates classes with the KHR system[11] and select a proper candidate. The quantitative quality we proposed have merits to compare and to evaluate the reusable candidates classes.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.385-387
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• 2011

본 논문에서는 이기종 무선망에서 제공되는 비디오 스트리밍 서비스의 품질을 보장하기 위해, 핸드오버 상황에 따라 변화하는 네트워크 상태에 적응적인 스트리밍 품질 적응 기법을 제안한다. 제안하는 기법은 패킷 페어 방식을 이용하여 네트워크의 가용대역폭을 측정하고 핸드오버 상황 공지 메시지를 이용하여 핸드오버 상황을 빠르게 인지함으로써 핸드오버로 인한 네트워크 가용대역폭 변화에 능동적으로 대응하며 네트워크 상태에 적응적으로 비디오 스트림의 품질을 조절한다. 실험을 통해 제안하는 기법이 핸드오버 상황에서 비디오 패킷 손실을 감소시켜 비디오의 재생 품질을 보장할 수 있음을 확인하였다.

• Journal of KIISE:Software and Applications
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• v.26 no.3
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• pp.393-400
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• 1999

클래스에 관한 재사용 관련 정보는 기능.환경면에서 정보와 품질 메트릭 정보로 구분할 수 있다. 기능.환경면에서 정보는 재사용 부품의 기능과 구현 환경에 관한 정보이며, 품질메트릭 정보는 재상용 부품들의 재사용성을 가시적으로 측정할 수 있는 정보이다. 클래스의 재사용성을 측정하기 위해서는 클래스의 절차적이고 객체지향적인 특성들을 모두 고려하여야 한다. 그러므로 본 논문에서는 클래스에 관한 재사용성 관련 정보를 소개하고 품질 메트릭 정보를 정량화시키는 정의식들을 제안하고, 클래스 코드로부터 기능.환경면으로 정보와 품질 메트릭 정보를 추출 및 측정하였다

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.426-431
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• 2010

68% of the manufacturing costs of solar cell wafer can be attributed to the slurry. The recycling of slurries is mandatory for reducing the costs of manufacturing wafering production, and the disposal of industrial waste, as well as for cutting down pollution levels. Slurries are currently being recycled using the centrifuge(decanter) method. However, this method is less than optimal as it does not completely remove the fine particles, leading to low quality. Also, be cause of the incomplete separation from the oil, it causes the impurities in the dried slurries. This study aims to develope a new recycling technology that overcomes the flaws of the centrifuge by utilizing chemicals. It will provide a total solution to the crucial process of recycling slurries in the making of solar cell wafer, by increasing the efficiency and renewable rate.

• Smart Media Journal
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• v.12 no.11
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• pp.145-153
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• 2023

In a P2P-based distributed storage system where peers frequently join and leave, it is essential to guarantee not only data availability but also playback quality comparable to that provided by local storage devices when playing back video files with real-time constraints. In addition, cloud storage services based on distributed storage systems provide each user with the functionality to share their files with other users, so when multiple users request playback of the same video file at the same time, all playback should be supported seamlessly in real time. Therefore, in this paper, we propose a scheme that process multiple simultaneous playback requests for each video file in real time as well as data availability in a P2P-based distributed storage system that supports file sharing. This scheme can support real-time simultaneous playback and efficiently use storage space by adjusting the amount of redundant data encoded through erasure coding according to the number of concurrent playback requests for each video file.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.236-238
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• 2006

본 논문은 동기화 구간 조정을 처리하기 위해 지연 지터를 적용함으로써 트래픽 증가로 인한 미디어 데이터의 손실 시간 및 지연시간의 변화로 인한 데이터 손실을 감소시켰다. 그리고 스무딩 버퍼의 대기 시간을 가변으로 처리함으로써 지연시간의 변화로 인한 불연속을 감소시켰다. 제안된 논문은 고품질 서비스의 보장을 요구하는 시스템에 적합하며, 재생율 증가와 손실율 감소 등 서비스 품질을 향상시켰다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1580-1580
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• 2007

광디스크를 재생 및 기록 가능한 기기는 그동안 IT에 용이한 컴퓨터 중심의 ODD(Optical Disc Drive)를 기반으로 급속히 발전해 오고 있었으나, 홈 엔터테인먼트의 발전과 이에 대한 관심의 증폭으로 AV용의 레코더가 2000년대에 등장하게 되었다. AV용 DVD 레코더의 경우 PC용 ODD에 비해 소음 및 세트 내부 온도 등 환경의 영향을 많이 받고, 여러 규격들을 만족해야 하기 때문에 구현에 많은 어려움과 제약이 따른다. 그리고 DVD 레코더는 방송 등을 스트림 기록해야 하므로 기록 신뢰성에 더욱 엄격함을 요구한다. 이에 기록 품질에 관련된 중요 Factor들이 존재하게 된다.