• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.329-334
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• 2006

최근 방송통신융합 기술에 대한 관심이 높아지고 있는 상황에서 주문형비디오 서비스에 대한 관심도 증가하고 있다. 본 논문에서는 주문형비디오 서비스의 구현을 위해 기존의 배칭 기법 중 Fast Data broadcasting 방식을 활용한 패칭 기법을 제안한다. 대역폭이 제한되어 있는 통신 환경에서 사용자는 요청한 비디오를 시청하기까지 일정 시간을 기다려야 하는데, 사용자 요청 시점 이전 데이터를 Fast Data broadcasting 방식을 적용한 패칭 채널을 통해 전송함으로써 대기 시간을 크게 줄이는 효과를 얻을 수 있다.

• The KIPS Transactions:PartB
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• v.12B no.7 s.103
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• pp.775-782
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• 2005

In this paper, we propose multicast technique in order to reduce the required network bandwidth by n times, by merging the adjacent multicasts depending on the number of HENs (Head-End-Nodes) n that request the same video. Allowing new clients to immediately join an existing multicast through patching improves the efficiency of the multicast and offers services without any initial latency. A client might have to download data through two channels simultaneously, one for multicast and the other for patching. The more the frequency of requesting the video is, the higher the probability of caching it among HENs increases. Therefore, the requests for the cached video data can be served by HENs. Multicast from server is generated when the playback time exceeds the amount of cached video data. Since the interval of multicast can be dynamically expanded according to the popularity of videos, it can be reduced the server's workload and the network bandwidth. We perform simulations to compare its performance with that of conventional multicast. From simulation results, we confirm that the Proposed multicast technique offers substantially better performance.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.427-432
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• 2003

In contact-type multiview 3 dimensional imaging systems, the optimum design parameters are not easily found because of difficulty in determining the size of viewing zone. Two factors related with the viewing zone, such as different view image patching and the widths of the viewing regions are discussed to explain the difficulty.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.784-791
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• 2005

To provide VoD Service on the Internet VoD server is required to have a large amount of system resource and network bandwidth. Therefore, overlay Multicast schemes are considered as suitable alternatives but they also have some drawbacks to support on-demand media services. In this paper, we propose an overlay multicast based on-demand media service scheme which could exploit server's system resource and its network bandwidth efficiently. Proposed scheme uses shared buffer of clients involving the relay of traffic and Patching while it gives no restrictions to this scheme compared with unicast. Our simulation results show that proposed scheme can support more user than unicast and improve the network performance at the same time.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.292-298
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• 2001

An experimental investigation of the effect of composite patching repair was conducted to characterize the fatigue crack growth behavior in thick A16061-T6 (6mm) panels with single bonded patch by fiber reinforced composite patch. Four patch lengths and no patch plate were examined. An analytical procedure, involving three-dimensional finite element method having three layers to model cracked aluminum plate, epoxy by adhesive and composite patch, is calculated the stress intensity factors. From the calculated stress intensity factors, the fatigue crack growth rates are obtained. At the single patching type, different fatigue crack growth ratios through the plate thickness were investigated by using the experimental and analytical results. The results demonstrated that there was a definite variation in fatigue life depending on the size of composite patch. While crack reached the patch end, retardation of crack growth was also revealed in the bonded repair.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.1
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• pp.52-57
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• 2007

One of the hot issues in composite patching is to reduce the thermal residual stresses between composite patch and aluminum surface which occurs after bonding of composite patch. In this study, the edge crack patching is adopted for different curing cycles. For the analysis, three layer Mindlin plate elements are used, and Paris' law is adopted to predict the fatigue life of composite patch plate. The analysis results show a good agreement with the experimental fatigue life and this technique can be applied for the prediction of fatigue life of aircraft structures.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.3
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• pp.24-29
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• 2019

The paste-type adhesive can be stored for a certain period of time and can be cured at room temperature. So it is mainly used for crack patching repair of aircraft airframe structures. This study analysed the influence of environmental factors and evaluated the adherence strength characteristics according to the adherence delay time of the paste-type adhesive. The test specimens were made of aluminum alloy(AL 2024-T3) with reference to ASTM D1002 which is generally performed to measure the adherence strength of the adhesive used for metal bonding. As a result of analysing the influence of temperature and humidity, it was found that the optimal temperature range is $24.5{\pm}0.5^{\circ}C$ and the optimal humidity range is $71{\pm}1%$ for maintenance work of the aircraft using EA-9320 adhesive. In addition, the adherence strength did not decrease with the inherent application time of the EA-9320, but it was found that the adherence strength dropped rapidly when the applied time exceeded the inherent application time of it.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.155-162
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• 2006

It was well known that how much seriously the Internet worm such as the Code Red had an effect on our daily activities. Recently the rapid growth of the Internet speed will produce more swift damage us in a short term period. In order to defend against future worm, we need to understand the propagation pattern during the lifetime of worms. In this paper, we analyze the propagation pattern of the Code Red worm by a computer simulation. In particular, we show that an existing simulation result about the number of infectious hosts does not match the observed data, and then we introduce a factor of revised human countermeasures into the simulation. We also show the simulation results presenting the importance of patching and pre-patching of the Internet worm.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1116-1119
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• 2009

최근 그룹 통신 분야에서 전통적으로 대표되는 IP 멀티캐스트의 대안기술로서 호스트기반 멀티캐스트 및 P2P시스템은 기존의 IP 멀티캐스트의 단점을 극복하고자 하는 연구이다. 이러한 호스트기반 멀티캐스트는 사용자 중심의 서비스를 제공함으로써 다양한 네트워크 환경에서 누구나 사용자들이 효율적으로 데이터를 공유하게 해주고 있다. 본 논문에서는 이러한 협동 기반의 호스트 멀티캐스트를 사용하여 미디어 서비스를 제공하는 VOD 시스템 전반에 관한 연구를 수행하고 이러한 VOD의 서비스를 고도화 하고자 한다. 보다 구체적으로는 패칭 기법을 사용하여 사용자간의 전달 지연을 최소화 할 수 있는 효율적인 자료 전송 경로를 설정 방법과 주문형 비디오 서버를 위한 현실적인 호스트 기반 멀티캐스트 트리 구성 모델을 제시하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.510-512
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• 2023

In order to enhance a model's capability for detecting facial expressions, this research suggests a pipeline that makes use of the GradCAM component. The patching module and the pseudo-labeling module make up the pipeline. The patching component takes the original face image and divides it into four equal parts. These parts are then each input into a 2Dconvolutional layer to produce a feature vector. Each picture segment is assigned a weight token using GradCAM in the pseudo-labeling module, and this token is then merged with the feature vector using principal component analysis. A convolutional neural network based on transfer learning technique is then utilized to extract the deep features. This technique applied on a public dataset MMI and achieved a validation accuracy of 96.06% which is showing the effectiveness of our method.