• 대한임베디드공학회논문지
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• 제10권6호
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• pp.353-362
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• 2015

In order to provide smart devices with high quality multimedia streaming services, an adaptive streaming technique over HTTP has been received much attention recently and the Dynamic Adaptive Streaming over HTTP (DASH) standard has been established. In DASH, however, the technique to select an appropriate quality of multimedia based on the performance metrics measured in a smart device might have some difficulties to reflect the capabilities of other neighboring smart devices and dynamic network conditions in real time. To solve the problem, this paper proposes a novel software agent approach, called DASH agent (DA), which gathers and analyzes the device capabilities and dynamic network conditions in real time and finally determines the highest achievable quality of segment to meet the best Quality of Experience (QoE) in current situations. The simulation results show that our approach provides higher quality of multimedia segments with less frequency of quality changes to lower quality of multimedia segments.

• 정보와 통신
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• 제12권10호
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• pp.76-86
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• 1995

최근 우리는 광대역종합정보통신망과 멀티미디어 통신망외에 개안휴대통신망의 시대를 맞이하고 있다. 미래에 통신 서비스는 다양한 정보의 송수신 뿐만 아니라 언제 어디서든지 어느 누구와도 통신이 가능하게 하는 시대를 맞이할 것이다. 이러한 요구는 망에서 제공되는 통신 시스템 자체의 발전과 그 통신망을 기반으로하는 정보의 종류와 기능의 다양화에 기반을 두고 구현될 것이다. 본 논문에서는 이러한 요구를 모두 충족시킬 수 있는 새로운 망의 구조와 제어방법을 제안한다. 우선 첫째로 미래의 서비스 변화나 요구사항, 망 설계시 요구되는 사항과 ,또 그러한 망을 실제로 구현 설치할 때 필요한 사항등을 제시한다. 그리고 이러한 요구사항들을 충족 시킬 수 있는 새로운 망으로서 Broadband personalized multimedia network (BPMN)을 제안하고 그 제어방법 및 운용방법등을 제안한다. 제안된 망은 지능적 서비스나 기능은 모두 부가적인 장비나 서비스 제공자에 의해 제공되는 모듈화된 구조로 기존의 망으로부터의 발전에 적합하며 새로운 망의 기술이나 서비스의 추가 또한 쉽게 이루어질 수 있는 구조이다. 망의 제어도 지역적 분산형태로 다양한 서비스를 각각의 기능에 알맞도록 선택하여 제공할 수 있는 완전 분산제어 방법을 새로이 제안하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.125-128
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• 2001

Nowadays, Internet users are widespread internationally. Fallowing the users requirements, server has to transfer real-time multimedia data to many clients. Multicast can significantly reduce the system overhead and the network resource waste, so it supports efficient mechanism when server has to transfer same data to many clients. We can deliver multimedia data transfer in real-time using Patching Algorithm which has no delay for service request. And multicast algorithm can support different network bandwidth using Receiver driven Layered Multicast under heterogeneous environment network. The purpose of this paper is to suggest an algorithm that can create new multicast group adequately and transfer real-time multimedia data efficiently under heterogeneous environment.

• 대한의용생체공학회:의공학회지
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• 제27권2호
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• pp.59-63
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• 2006

Magnetocardiogram (MCG) topography is a useful diagnostic technique that employs multi-channel magnetocardiograms. Measurement of artifact-free MCG signals is essenctial to obtain MCG topography or map for a diagnosis of human heart. Principal component analysis (PCA) combined with an artificial neural network (ANN) is proposed to remove a pulse-type artifact in the MCG signals. The algorithm is composed of a PCA module which decomposes the obtained signal into its principal components, followed by an ANN module for the classification of the components automatically. In the experiments with volunteer subjects, 97% of the decisions that were made by the ANN were identical to those by the human experts. Using the proposed technique, the MCG topography was successfully obtained without the artifact.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.414-435
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• 2017

As network adaptive streaming technology becomes increasingly common, transport protocol also becomes important in guaranteeing the quality of multimedia streaming. At the same time, because of the appearance of high-quality video such as Ultra High Definition (UHD), preventing buffering as well as preserving high quality while deploying a streaming service becomes important. The Internet Engineering Task Force recently published Multipath TCP (MPTCP). MPTCP improves the maximum transmission rate by simultaneously transmitting data over different paths with multiple TCP subflows. However, MPTCP cannot preserve high quality, because the MPTCP subflows slowly increase the transmission rate, and upon detecting a packet loss, drastically halve the transmission rate. In this paper, we propose a new multipath congestion control scheme for high-quality multimedia streaming. The proposed scheme preserves high quality of video by adaptively adjusting the increasing parameter of subflows according to the network status. The proposed scheme also increases network efficiency by providing load balancing and stability, and by supporting fairness with single-flow congestion control schemes.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.197-205
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• 2022

The Cyber Physical System(CPS) is an important concept in achieving SMSs(Smart Manufacturing Systems). Generally, CPS consists of physical and virtual elements. The former involves manufacturing devices in the field space, whereas the latter includes the technologies such as network, data collection and analysis, security, and monitoring and control technologies in the cyber space. Currently, all these elements are being integrated for achieving SMSs in which we can control and analyze various kinds of producing and diagnostic issues in the cyber space without the need for human intervention. In this study, we focus on implementing a production equipment monitoring system related to building a SMS. First, we describe the development of a fog-based gateway system that links physical manufacturing devices with virtual elements. This system also interacts with the cloud server in a multimedia network environment. Second, we explain the proposed network infrastructure to implement a monitoring system operating on a cloud server. Then, we discuss our monitoring applications, and explain the experience of how to apply the ML(Machine Learning) method for predictive diagnostics.

• 한국멀티미디어학회논문지
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• 제19권7호
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• pp.1166-1178
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• 2016

In Internet of Things (IoT) environments, billions of interconnected devices and multimedia sensors generate a huge amount of multimedia traffic. Since the environment are in general deployed as a server-centric architecture wireless sensor networks could be bottlenecks between IoT gateways and IoT devices. The bottleneck causes high power consumption of the device and triggers very heavy network overload by transmission of sensing data. The deterioration could decrease the quality of multimedia streaming service due to delay, loss, and waste of device power. Thus, in this paper, we propose a context-based adaptive multimedia streaming scheme to support enhanced QoS and low power consumption in IoT environments. The goal of the scheme is to increase quality score per voltage of the streaming service, given an adaptation algorithm with context that are classified network and hardware such as throughput, RTT, and CPU usage. From the both context, the quality score per voltage is used in the comparison of a only network context-based adaptive multimedia streaming scheme, a fixed multimedia streaming and our scheme. As a result, we achieves a high improvement that means the quality score per voltage is increased up to about 4, especially in case of resolution change.

• 한국통신학회논문지
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• 제42권5호
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• pp.1049-1057
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• 2017

차량용 멀티미디어 시스템은 자동차 산업에 있어서 매우 중요한 요소 중 하나이다. 특히, 프리미엄 고속버스와 같은 고급상용차에서의 멀티미디어 시스템은 더욱 중요하다. 우리는 본 논문에서 MOST150을 기반으로 MEP(MOST Ethernet Packets)을 이용해 프리미엄 고속버스용 멀티미디어 시스템 구조를 제안했고, Prototype을 설계 및 구현했다. 제안한 시스템 구조를 구현하기 위해 멀티미디어 시스템이 운용될 수 있는 I.MX6기반의 Board를 설계했다. 소프트웨어는 Open Source Platform인 Android를 기반으로 프리미엄 고속버스용 멀티미디어 시스템을 설계했다. MOST는 고속의 멀티미디어 네트워크 기술이며, 차량의 멀티미디어시스템 설계에 사용된다. 기본적으로 링 토폴로지(Ring Topology)를 사용하고, 최대 64개의 MOST 장치를 연결할 수 있다. 또한 MOST 네트워크는 광모듈(POF)을 이용해 통신하기 때문에 EMII(Electro-Magnetic Interference) 및 EMC(Electro-Magnetic Compatibility) 요구조건을 충족한다.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.473-476
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• 2021

The article used a complex system of research methods: observation of the course of the educational process, analysis of literature on pedagogy, teaching methods, modern pedagogical technologies; analysis of the experience of using multimedia in the study of disciplines. The theoretical significance of the article: the definition of multimedia programs is given, the advantages and disadvantages of using multimedia programs are revealed, the basic principles of teaching using multimedia programs are revealed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
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• pp.145-148
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• 2000

ATM network is considered as best suitable technology for multimedia service in various aspects such as bandwidth, capability of traffic expandability and so on. In this paper, we suggested a buffer management algorithm in ATM network to improve overall network performance with threshold and auxiliary buffer whose input consists of superpositiI on of voice and multimedia data traffic. To evaluate the proposed buffer management algorithm simulations are executed with four priorities, that is delay and loss priorities and the results are proved that network throughput is improved better than the existing partial buffer method.