• Elastomers and Composites
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• v.48 no.1
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• pp.67-75
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• 2013

E-TPE (Engineering Thermoplastic Polyether Ester) was Ester Elastomer with functional groups as recycling and fast processability. In addition, if the car's lightweight enough to highlight eco-friendly materials that help to improve fuel economy has become. Have all the attributes of the rubber and engineering plastics E-TPE the available temperature area is spacious, heat resistance and oil resistance is excellent but getting attention as a new material in the field of auto parts in the field of electrical and electronic domestic depends entirely on imports by the lack of core technology and has been research and development is urgently needed. In this study, the hard segments, polyester (TPEE) as the base soft elastomers of the segments Ethylen-prophylene-Copolymer and CSM (Choloro sulphonated polyethylene Rubber), VAMAC (Ethylene Acrylic Rubber), NBR (Acrylonitrin Butadiene Rubber), 1, 3-Phenylene-bisoxazoline is dealing with Dynamic Vulcanized by content and added rubber properties, thermal variation observed. As a result, the properties of the dynamic vulcanization with NBR compared to other rubber heat resistance and oil resistance is on the increase.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.13-15
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• 2011

현재 무선 통신을 이용한 IPTV서비스에 대한 요구가 지속적으로 증가 되고 있다. 따라서 제한된 자원을 다수의 사용자들에게 효율적으로 전송하기 위한 기술이 개발되어야 한다. 본 논문에서 우리는 무선 IPTV의 VOD 시스템 성능 향상을 위해 효율적인 Batching 기법과 채널을 효과적으로 사용하기 위하여 Network coding을 활용한 기법을 제안한다. 제안된 기법은 채널을 효과적으로 사용하기 위하여 Network coding을 활용하였다. 현재의 Batching 기법은 다수의 채널을 사용하는 반면에 제안된 기법은 한 개의 채널에서 2개 이상의 세그먼트를 전송함으로써 얻어지는 채널사용의 효율성을 보여준다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.45-51
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• 2006

Recently, the IDS(Intrusion Detection System) using a video camera is an important part of the home security systems which start gaining popularity. However, the video intruder detection has not been widely used in the home surveillance systems due to its unreliable performance in the environment with abrupt illumination change. In this paper, we propose an effective moving edge extraction algerian from a sequence image. The proposed algorithm extracts edge segments from current image and eliminates the background edge segments by matching them with reference edge list, which is updated at every frame, to find the moving edge segments. The test results show that it can detect the contour of moving object in the noisy environment with abrupt illumination change.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.40-48
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• 1996

In this paper, a 40 dimensional segment vector with 4 frame and 7 frame width in every monosyllable interval was compressed into a 10, 14, 20 dimensional vector using K-L expansion and neural networks, and these was used to speech recognition feature parameter for CHMM. And we also compared them with CHMM added as feature parameter to the discrete duration time, the regression coefficients and the mixture distribution. In recognition test at 100 monosyllable, recognition rates of CHMM +${\bigtriangleup}$MCEP, CHMM +MIX and CHMM +DD respectively improve 1.4%, 2.36% and 2.78% over 85.19% of CHMM. And those using vector compressed by K-L expansion are less than MCEP + ${\bigtriangleup}$MCEP but those using K-L + MCEP, K-L + ${\bigtriangleup}$MCEP are almost same. Neural networks reflect more the speech dynamic variety than K-L expansion because they use the sigmoid function for the non-linear transform. Recognition rates using vector compressed by neural networks are higher than those using of K-L expansion and other methods.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.40-47
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• 2009

Recently, dynamic proxy caching has been proposed on the distributed environment so that media objects by user's requests can be served directly from the proxy without contacting the server. However, it makes caching challenging due to multimedia large sizes, low latency and continuous streaming demands of media objects. To solve the problems caused by streaming demands of media objects, this paper has been proposed the grouping scheme with fuzzy filtering based on partition and mapping. For partition and mapping, this paper divides media block segments into fixed partition reference block(R$_f$P) and variable partition reference block(R$_v$P). For semantic relationship, it makes fuzzy relationship to performs according to the fixed partition temporal synchronization(T$_f$) and variable partition temporal synchronization(T$_v$). Simulation results show that the proposed scheme makes streaming service efficiently with a high average request response time rate and cache hit rate and with a low delayed startup ratio compared with other schemes.

• Journal of KIISE:Databases
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• v.34 no.5
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• pp.448-464
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• 2007

Location-Based Services (LBSs) provide results to queries according to the location of the client issuing the query. In LBS, techniques such as caching and prefetching are effective approaches to reducing the data transmission from a server and query response time. However, they can lead to cache inefficiency and network overload due to the client's mobility and query pattern. To solve these drawbacks, we propose a semantic prefetching (SP) scheme using prefetching segment concept and improved cache replacement policies. When a mobile client enters a new service area, called semantic prefetching area, proposed scheme fetches the necessary semantic information from the server in advance. The mobile client maintains the information in its own cache for query processing of location-dependent data (LDD) in mobile computing environment. The performance of the proposed scheme is investigated in relation to various environmental variables, such as the mobility and query pattern of user, the distributions of LDDs and applied cache replacement strategies. Simulation results show that the proposed scheme is more efficient than the well-known existing scheme for range query and nearest neighbor query. In addition, applying the two queries dynamically to query processing improves the performance of the proposed scheme.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.69-86
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• 2022

The railway is widely used to transport passengers and freight due to its punctuality and large transport capacity. The recent remarkable development in construction technology enables various subsea railway tunnels for continent-continent or continent-island connectivity. In Korea, design and construction experience is primarily based on the successful completion of the Boryeong subsea tunnel (2021) and the Gadeok subsea tunnel (2010). However, frequent earthquakes with diverse magnitudes, globally induced and continuously increased the awareness of seismic risks and the frequency of domestic earthquakes. The effect of an earthquake on the subsea tunnel is very complicated. However, ground conditions and seismic waves are considered the main factors. This study simulated four ground types of 3-dimensional numerical models, such as soil, rock, composite, and fractured zone, to analyze the effect of ground type and seismic wave. A virtual subsea railway shield tunnel considering external water pressure was modeled. Further, three different seismic waves with long-term, short-term, and both periods were studied. The dynamic analyses by finite difference method were performed to investigate the displacement and stress characteristics. Consequently, the long-term period wave exhibited a predominant lateral displacement response in soil and the short-term period wave in rock. The artificial wave, which had both periodic characteristics, demonstrated predominant in the fractured zone. The effect of an earthquake is more noticeable in the stress of the tunnel segment than in displacement because of confining effect of ground and structural elements in the shield tunnel. 

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.19-26
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• 2016

In this paper, the dynamic buffering based smart OTT platform was proposed, and analyzed for adaptive bit-rate video delivery with the optimization of HLS (HTTP Live Streaming). This platform consists of the software platform between sever and client which detects the bandwidth capacity, and adjusts the quality of the streaming for multiple bit-rates resolutions. In order to apply adaptive buffering, two buffers are added to the basic HLS player, and each buffer is responsible for constantly buffering a previous and the next channels relative to the current channel. This adaptive transmitting with smart OTT platform is superior to delivering a static video file at a single buffering, because the video stream of adaptive double buffers can be switched streaming according to client's available network speed. As a result, this proposed smart OTT can be cooperated to the application of HLS server with segmented H.265 MPEG-2 TS video & m3u8 files with its information based on the optimized transmission channel state of live and VOD, and applied to PLC transmission, too.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.97-106
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• 2010

Various time series representation methods have been suggested in order to process time series data efficiently and effectively. SAX is the representative time series representation method combining segmentation and discretization techniques, which has been successfully applied to the time series classification task. But SAX requires a large number of segments in order to represent the meaningful dynamic patterns of time series accurately, since it loss the dynamic property of time series in the course of smoothing the movement of time series. Therefore, this paper suggests a new time series representation method that combines PIPs detection and Persist discretization techniques. The suggested method represents the dynamic movement of high-diemensional time series in a lower dimensional space by detecting PIPs indicating the important inflection points of time series. And it determines the optimal discretizaton ranges by applying self-transition and marginal probabilities distributions to KL divergence measure. It minimizes the information loss in process of the dimensionality reduction. The suggested method enhances the performance of time series classification task by minimizing the information loss in the course of dimensionality reduction.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.9-15
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• 2016

In this paper, we propose a smart HLS(HTTP Live Stream) platform with dynamic single buffering for the best transmission of adaptive video bit-rates. This smart HLS can optimizes the channel transition zapping-time with the monitoring of bandwidth between HLS server and OTT(Over The Top) client. This platform is designed through the control of video stream due to proper multi-bitrates and bandwidths. This proposed OTT can decode the live and VOD(Video On Demand) videos with the buffering of optimumal bitrate. And, the HLS can be cooperated with a smart OTT, and segmented for the m3u8 files of H.265 MPEG-2 TS(Transport Stream) videos. As a resullt, this single buffer based smart OTT can transmit optimal videos with the maximum data buffering according to the adaptive bit-rate depending on the network bandwidth efficiency and the decoded VOD video, too.