• 한국가시화정보학회지
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• 제1권2호
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• pp.52-57
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• 2003

The present paper investigated the effect of ultrasonic vibrations on the melting process of a phase-change material (PCM). The melting process in the square cavity with a heated vertical wall has been studied in terms of acoustic streaming. In the present study, applying with ultrasonic vibrations to the liquid were found to induce acoustic streaming which was clearly observed using by a particle image velocimetry (PIV) and a thermal infrared camera. The experimental results revealed that acoustic streaming could accelerate the melting process as much as 2.5 times, compared to the rate of natural melting (i. e., the melting without acoustic streaming). In addition, temperature and Nusselt numbers over time provided conclusive evidence of the important role of the acoustic streaming on the melting phenomena of the PCM.

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.213-219
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• 2017

Streaming server is that an image produced in real time or a file form of image produced ahead consists of SNS service, and the relay module of streaming server includes output management module that set an output channel more than 2 and control transmission of video content. This thesis intends to suggest how to stream through plural output channel that contains output channel of external streaming server using relay module and do streaming provided to terminal receiving image, and streaming server, streaming system for this. Thus, by extending output channel sending out image to output channel of external streaming server, the scale of streaming server is not limited and the process allotting external streaming server into output channel sending the image becomes simple, so management of output channel becomes efficient even when sending several images.

• 상하수도학회지
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• 제18권4호
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• pp.522-528
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• 2004

Microfiltration with in-line rapid coagulation for drinking water production was examined. The in-line rapid coagulation was conducted using newly developed mixing device instantaneous flash mixer. The flux decline during membrane filtration was monitored with coagulant dosage varied. Flux decline was minimized at 1.1mg/L of coagulant dosage, where streaming potential of coagulated water was near zero. The optimum dosage for the process control was explained by dimensionless distance (${\kappa}{\times}a$) of particle pairs, obtained from electrophoresis parameter describing electrostatic repulsion relative to Van der Waals energy between particle pairs in the pre-coagulated water.

• 방송공학회논문지
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• 제23권4호
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• pp.549-558
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• 2018

360 VR(Virtual Reality) 비디오와 같이 고품질의 비디오를 기존 케이블 망에서 IPTV 또는 OTT(Over the Top) SettopBox과 같은 저사양 미디어 서비스 기기를 통해 저지연 라이브 스트리밍 서비스를 할 수 있도록 MPEG DASH(Dynamic Adaptive Streaming over HTTP) 기반의 스트리밍 서버를 설계하고 구현하였다. 또한, 서버 응답 지연 시간을 줄이기 위해 스트리밍 영상 파일(MPD, Segment Files)을 메모리상에 캐싱 하여 서비스 할 수 있는 관리 프로세스를 설계하고 적용하였다. 그리고 실험을 통해 bitrate가 50,000kbps 이상이고, 8K@60P 급의 고품질 분할 영상 스트리밍을 지원하는 것을 확인하였다

• 한국산업정보학회논문지
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• 제11권3호
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• pp.69-81
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• 2006

In this paper, an adaptive algorithm is proposed in streaming MPEG-4 contents with fluctuating resource amount such as throughput of network conditions. In the area of adaptive streaming issue, a lot of researches have been made on how to represent encoded media(such as video) bitstream in scalable way. By contrast, MPEG-4 supports object-based multimedia content which is composed of various types of media streams such as audio, video, image and other graphical elements. Thus, it can be more effective to provide individual media streams in scalable way for streaming object-based content to heterogeneous environment. The proposed method provides the multiple media streams corresponding to an object with different qualities and bit rate in order to support object based scalability to the MPEG-4 content. In addition, an optimal selection of the multiple streams for each object to meet a given constraint is proposed. The selection process is adopted a multiple choice knapsack problem with multi-step selection for the MPEG-4 objects with different scalability levels. The proposed algorithm enforces the optimal selection process to maintain the perceptual qualities of more important objects at the best effort. The experimental results show that the set of selected media stream for presenting objects meets a current transmission condition with more high perceptual quality.

• 한국해안·해양공학회논문집
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• 제32권1호
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• pp.55-68
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• 2020

너울이 우세한 온화한 해양환경에서 출현하는 beach cusp에서의 경계층 streaming 수리특성을 살펴보기 위해 edge waves의 천수 과정을 수치 모의하였다. Beach cusp을 유지하는 것으로 알려진 synchronous edge waves는 같은 주기와 파고를 지니는 두 개의 Cnoidal wave가 전면해역에서 비스듬히 조우 되도록 조파하여 재현하였다. Beach cusp의 진폭 A_B과 파장 L_B은 맹방 해변에서 수행된 관측결과를 토대로 각각 1.25 m, 18 m로 선정하였다. 모의결과 천수 각 단계에서 예외 없이 경계층 streaming을 관측할 수 있었으며 최대 경계층 streaming은 사주 정점에서 발생하였다. 주기가 가장 짧은 RUN 1의 경우 그 세기는 약 0.32 m/s 내외에 분포하며 이러한 수치는 free stream 유속 u_∞ 진폭의 두 배에 달하는 것으로 wave Reynolds 응력에 기반한 Longuet-Higgins(1957)의 해석 해와는 상당한 차이를 보였다. 수치 모의과정에서 온화한 해양환경에서 해빈이 복원되는 과정을 특정할 수 있었으며 이 과정을 정리하면 다음과 같다: 너울로 구성된 파랑 무리에서 성분 파랑 간의 공진성 상호작용으로 생성된 외 중력파가 쇄파선 인근에 도달하는 경우 중력으로 인한 가속이 더해진 Phase II 파랑 궤도 운동으로 수면 가까이 상승한 많은 모래가 쇄파 시 발생하는 파 마루로부터 시작된 up-rush에 의해 전 빈 정점 가까이 이동하며 이 과정에서 발생하는 침투로 인해 퇴적되는 것으로 모의 되었다.

• 산업경영시스템학회지
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• 제37권4호
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• pp.187-192
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• 2014

Lot-streaming is the process of splitting a job (lot) into sublots to allow the overlapping of operations between successive machines in a multi-stage production system. A new genetic algorithm (NGA) is proposed for an n-job, m-machine, lot-streaming flow shop scheduling problem with equal-size sublots in which the objective is to minimize the total stretch. The stretch of a job is the ratio of the amount of time the job spent before its completion to its processing time. NGA replaces the selection and mating operators of genetic algorithms (GAs) by marriage and pregnancy operators and incorporates the idea of inter-chromosomal dominance and individuals' similarities. Extensive computational experiments for medium to large-scale lot-streaming flow-shop scheduling problems have been conducted to compare the performance of NGA with that of GA.

• 한국멀티미디어학회논문지
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• 제24권4호
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• pp.538-549
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• 2021

In this paper, we introduce a technique for 360-degree panoramic video streaming with multiple virtual cameras in real-time. The proposed technique consists of generating 360-degree panoramic video data by ORB feature point detection, texture transformation, panoramic video data compression, and RTSP-based video streaming transmission. Especially, the generating process of 360-degree panoramic video data and texture transformation are accelerated by CUDA for complex processing such as camera calibration, stitching, blending, encoding. Our experiment evaluated the frames per second (fps) of the transmitted 360-degree panoramic video. Experimental results verified that our technique takes at least 30fps at 4K output resolution, which indicates that it can both generates and transmits 360-degree panoramic video data in real time.

• 한국멀티미디어학회논문지
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• 제12권7호
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• pp.979-988
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• 2009

디지털 콘텐츠의 불법 복제와 저작권 침해는 디지털 콘텐츠의 산업의 발전을 저해하고 있다. 이러한 문제로 인해 다양한 DRM(Digital Rights Management) 시스템이 개발되고 있다. 그러나 초기 DRM 시스템은 콘텐츠의 사용 권리가 있는 사용자만이 해당 콘텐츠를 접근할 수 있기 때문에 사용자가 다른 사용자에게 콘텐츠를 재배포하는 것은 쉽지 않았다. 이러한 문제를 해결하기 위해 다운로드 큰텐츠에 국한되어 재배포를 위한 초유통 서비스 구조가 출현하였다. 하지만 스트리밍 콘텐츠는 사용자가 직접 스트리밍 서버에 접속하여 콘텐츠를 접근하기 때문에 초유통이 제한되었다. 본 논문에서는 스트리밍 콘텐츠의 초유통을 위한 스트리밍 서버와 사용자를 연결할 수 있는 중계파일을 제안하였다.

• Journal of Information Technology Applications and Management
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• 제31권2호
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• pp.35-49
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• 2024

With the development of e-commerce, live streaming e-commerce, as an emerging marketing method, is on the rise. It integrates various ways of information delivery, providing consumers with unprecedented shopping experiences, particularly through its interactive nature, which can increase audience engagement and immersion. This study delves into how interactive elements in live streaming e-commerce influence consumer emotions and purchase intentions. By employing literature review and empirical analysis methods, we analyzed various interactive factors in the live streaming e-commerce environment and revealed the process through which these factors stimulate audience emotions and lead to specific purchasing behaviors. The results confirm that the interactive appeal of live streaming e-commerce significantly influences consumers' positive emotional responses, consequently enhancing purchase intentions. This study aims to explore the relationship between the interactive features of live streaming e-commerce and consumer emotional responses and purchase intentions, thereby filling theoretical gaps in the field of live streaming e-commerce and proposing new marketing theories. Additionally, by analyzing how interactive features stimulate consumers, optimal live content strategies can be proposed for live streaming e-commerce platforms and hosts, thus aiding in the improvement of marketing strategies and sales effectiveness.