• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권1호
• /
• pp.241-269
• /
• 2012

Wireless networks composed of multimedia-enabled resource-constrained sensor nodes have enriched a large set of monitoring sensing applications. In such communication scenario, however, new challenges in data transmission and energy-efficiency have arisen due to the stringent requirements of those sensor networks. Generally, congested nodes may deplete the energy of the active congested paths toward the sink and incur in undesired communication delay and packet dropping, while bit errors during transmission may negatively impact the end-to-end quality of the received data. Many approaches have been proposed to face congestion and provide reliable communications in wireless sensor networks, usually employing some transport protocol that address one or both of these issues. Nevertheless, due to the unique characteristics of multimedia-based wireless sensor networks, notably minimum bandwidth demand, bounded delay and reduced energy consumption requirement, communication protocols from traditional scalar wireless sensor networks are not suitable for multimedia sensor networks. In the last decade, such requirements have fostered research in adapting existing protocols or proposing new protocols from scratch. We survey the state of the art of transport protocols for wireless multimedia sensor networks, addressing the recent developments and proposed strategies for congestion control and loss recovery. Future research directions are also discussed, outlining the remaining challenges and promising investigation areas.

• Journal of Multimedia Information System
• /
• 제6권4호
• /
• pp.239-244
• /
• 2019

With the development of Cyber-Physical Systems(CPS), several technologies such as automation control, automotive and intelligent house systems have been developed. To enable communication among various components of such systems, several wired and wireless communication protocols are used. The Controller Area Network(CAN) is one of such wired communication protocols that is popularly used for communication in automobiles and other machinery in the industry. In this paper, we designed and implemented a response time analysis system for CAN communication. The reliable data transfer among various electronic components in a significant time is crucial for the smooth operation of an electric vehicle. Therefore, this system is designed to conveniently analyze the response time of various electronic components of a CAN enabled system. The priority for transmission of the messages in the CAN bus is determined by the message identifier. As the number of nodes increases the transmission of low priority messages is delayed due to the existence of higher priority messages on the bus. We used Raspberry Pi3 and PiCAN2 board to simulate the data transfer for studying the comparative delay in low priority nodes.

• 디지털콘텐츠학회 논문지
• /
• 제14권3호
• /
• pp.357-365
• /
• 2013

스마트폰의 대중화는 무선 통신의 사용 패턴을 음성 중심에서 데이터 통신 중심으로 바꾸어 놓았다. 무선 데이터 통신에 대한 요구는 지속적으로 증가하고 있으며 이를 만족시키기 위한 기반 시설 확충 비용이 크게 늘어나고 있다. 본 논문에서는 기회적 네트워크와 (opportunistic networks) 무선 통신을 함께 활용하여 멀티미디어 콘텐츠를 사용자들에게 배포함으로써 무선 통신의 사용량을 경감시킬 수 있는 기법을 제시한다. 이러한 기법을 사용함으로써 무선 통신 기반시설 확충에 대한 필요를 낮춤으로써 비용을 절약하는 동시에 사용자들의 데이터 통신에 대한 요구 또한 만족시킬 수 있다. 본 논문에서 제안한 기법은 에이전트 기반 시뮬레이션을 (agent-based simulation) 통하여 검증 하였다. 시뮬레이션 결과는 사용 환경에 따라 최대 70% 정도의 무선 통신 사용량을 기회적 네트워크를 통한 콘텐츠 배포로 대체할 수 있음을 보여 주었다.

• 전자공학회지
• /
• 제32권9호
• /
• pp.74-83
• /
• 2005

Recently, MPEG (Moving Picture Experts Group) has started a new standardization activity called MPEG Multimedia Middleware (M3W). This activity covers the standardization for a middleware rrith a set of APIs. The standard middleware, called M3W, will support independent multimedia applications for hardware and software such as operating systems so that the portability and interoperability of multimedia applications are greatly improved. In this article, we will introduce the recent works on M3W standardization including the rationale that motivates the activity with the advantages of having the standardized middleware for multimedia application, component technologies being considered for the M3W, and the current status of the standardization.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제9권3호
• /
• pp.269-273
• /
• 2005

Nowadays application of modem achievements of information technologies in science, engineering and education is usual phenomenon. Application of these technologies allows easily creating new methods of learning of mathematics. More of new methods of creation of multimedia electronic manuals on high mathematics are founded to application of multimedia and communication opportunities of the computer. But application only multimedia and communication opportunities of the computer at creation of multimedia electronic manuals on high mathematics is insufficient to elimination of 'gap' between training and studying high mathematics. So, we offer a new way of the decision of this problem: creation of a multimedia electronic manual on high mathematics with built-in a mathematical environment MathCad in the national language.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 1997년도 Proceedings International Workshop on New Video Media Technology
• /
• pp.55-60
• /
• 1997

Innovation on digital compression technology, high speed networking technology, digital broadcasting technology and distributed processing technology provides new interactive multimedia service that integrates telecommunication, broadcasting, and computer application. To meet the new trends, we focus our research direction to integrate the telecommunication services and the broadcasting services. For this purpose, we designed and implemented an interactive multimedia service platform based on the DAVIC specification. Our research results in the development of integrated interactive services and its experience will be feedback to the field trial service that will be launched from next year. In this paper, we will describe the overall architecture and system implementation results of the interactive multimedia service platform.

• 한국정보처리학회논문지
• /
• 제4권2호
• /
• pp.573-585
• /
• 1997

본 논문에서는 ATM환경하에서 다양한 멀티미디어 통신 서비스를 통합 제공할 수 있는 단말 시스템의 한가지 구조를 제안하고, 그에 따라, 프로토입으로 개발된 멀티미디어 통신 서비스 단말의 기능 및 시스템 구조를 소개하였다. 본 논문에서 제안한 단말의 형상은 관련 국제 표준안에 근거하여, 멀티미디어 단말 구현상의 기술적 어려움과 각 서비스별 미디어 품질 요구 사항 등을 고려하였으므로, 서로 다른 통신망 환경과 단말 환경에서 최대한의 상호 호환성을 보장하면서, 저렴하고 효율적인 단말기를 구현하는 한가지 해결책으로 사용될 수 있다. 본 논문에서는 소개하는 멀티미디어 통신 단말은 재안된 단말 시스템 참조 모델(Reference Model)에 따라, 다양한 멀티미디어 통신 서비스를 통합 제공할 수 있도록 설계되었으며, B-ISDN 시대의 궁극작년형상이 될 수는 없겠으나, 현재의 기술로 구현할 수 있는 가장 효율적인 단말이 될것이다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1225-1228
• /
• 1996

This paper describes the application area of the multimedia conference system for the electric power system operation. A variety of multimedia systems which are to be installed in the existing information communication network of KEPCO are introduced.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
• /
• pp.245-245
• /
• 2004

• 한국전자거래학회지
• /
• 제1권1호
• /
• pp.159-171
• /
• 1996

Nowadays, multimedia and Hypermedia become hot topics in information industry. Due to high capacity of media storage and fast communication network, it is possible to exchange text data as well as image, moving picture and voice. Especially to apply hypermedia under CALS standard environment, the relation between international standard and CALS standard needs to be considered. This study introduces conceptual background and processing model of HyTime (Hypermedia Time-based Structuring Language) which is a specification of hypermedia exchange, Hyper ODA (Hyper Open Document Architecture) which is a major multimedia communication basis, MMCF (Multimedia Communication Forum), AHM(Amsterdam Hypermedia Model), and DSRM(DAVIC System Reference Model) reference model which helps determination of hypermedia communication specification Although they are international standard, provisional standard or non-standard, it discusses the Possibility of adopting them as CALS standard. Hence, this paper chooses the best recommend for CALS among these models.