• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.757-764
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• 2002

This Paper describes our experiences with the design and implementation of a networked multimedia information management system in an object-oriented framework for distributed multimedia applications, and an integrated QoS-resource negotiation protocol which has been applied to a video server in our networked multimedia infrastructure. The salient features of our framework to support efficient multimedia streaming are explained. Next the paper explores the challenges faced in integrating the proposed QoS negotiation policy into the framework.

• Journal of Korea Multimedia Society
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• v.22 no.8
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• pp.887-896
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• 2019

In this paper, we discuss an optimization approach for time-synchronizations in networked simulators. This method is a sub-technology that is required to combine heterogeneous simulators into a single simulation. In previous time-synchronization studies, they had built a network system among networked simulators. The network system collects network packets and adds time-stamps to the networked packets based on the time that occurs in events of simulation objects in the individual simulators. Then, it sorts them in chronological order. Finally, the network system applies time-synchronization to each simulator participating in interworking sequentially. However, the previous approaches have a limitation in that other participating simulators should wait for while processing an event in a simulator in a time stamp order. In this paper, we attempt to solve the problem by optimizing time-synchronizations in networked simulation environments. In order to prove the practicality of our approach, we have conducted an experiment. Finally, we discuss the contributions of this paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.406-425
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• 2012

Deploying advanced home networking technologies and modern home-networked devices in residential environments provides a playground for new home applications and services. Because home multimedia entertainment is among the most essential home applications, this paper presents an appealing home media content sharing scenario: home-networked devices can discover neighboring devices and share local media content, as well as enormous amounts of Internet media content in a convenient and networked manner. This ideal scenario differs from traditional usages that merely offer local media content and require tedious manual operations of connection setup and file transfer among various devices. To achieve this goal, this study proposes a proxy gateway architecture for home multimedia content distribution. The proposed architecture integrates several functional mechanisms, including UPnP-based device discovery, home gateway, Internet media provision, and in-home media content delivery. This design addresses several inherent limitations of device heterogeneity and network interoperability on home and public networks, and allows diverse home-networked devices to play media content in an identical and networked manner. Prototypical implementation of the proposed proxy gateway architecture develops a proof-of-concept software, integrating a BitTorrent peer-to-peer client, a UPnP protocol stack, and a UPnP AV media server, as well as media distribution and management components on the OSGi home gateway platform. Practical demonstration shows the proposed design and scenario realization, offering users an unlimited volume of media content for home multimedia entertainment.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.1
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• pp.1-8
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• 2007

In this paper, we developed a file system architecture for portable multimedia devices. To enhance user convenience, the information about the stored files should be easily retrieved and organized. We defined NMD (Networked MetaData), which can organize the files in networked fashion by attaching user-defined attributes and relation between files. The NMD is stored in flash memory to utilize its nonvolatile property and low-power consumption, while multimedia files are stored in hard disk, an inexpensive mass storage. The experimental implementation showed that this architecture was able to save about 10% power compared to the hard disk NMD-store.

• Journal of Korea Multimedia Society
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• v.3 no.2
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• pp.157-163
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• 2000

Introduction of motion video including live video into network virtual reality systems makes virtual spaces more attractive. To handle live video in networked virtual reality s)'stems based on VRML, the scalability of networked virtual reality systems becomes very important on the internet where the performance of the network and the end systems varies dynamically. In this paper, a new quality control algorithm suitable for scalable networked virtual reality systems with live video capability is proposed. Our approach is to introduce the notion of the importance of presence (IoP) which represents the importance of objects in virtual spaces. According to IoPs, the degree of the deterioration of each object presentation will be determined in case of the starvation of system resources.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.11a
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• pp.471-474
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• 2000

오디오, 비디오를 취급하는 네트워크형 가상현실 시스템에서 가상공간의 품질은 사용 가능한 네트워크 린 컴퓨터의 자원에 크게 영향을 받는다. 본 논문에서는 가상공간의 품질을 제어하기 위해 IoP(Importance of Presence) 개념을 도입하고 이를 실제 네트워크형 가상현실 시스템에 적용하여 구현하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.101-106
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• 1996

This paper describes the system and network configurations of the Application Development Center for multimedia applications on Korean broadband testbed network. The center is primarily used for developing networked multimedia services funded by the Korean Ministry of Information and Communications. The center is quipped with ATM switch, multimedia workstations and PCs. More than 180 applications for the broadband testbed network are under development. Several examples will be presented in detail.

• Journal of Korea Multimedia Society
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• v.9 no.2
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• pp.208-214
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• 2006

Participants of a NVE(networked virtual environment) may have different hardwares and network environments, and to guarantee the fairness, messages of participants should be synchronized. A solution for the synchronization problem is to wait for a certain amount of time until the server processes the message. It is not easy to determine a suitable waiting period because of the trade-off between the fairness and the responsiveness. In this paper we propose a method to decide a waiting period by considering only the participants with small network delays and perform experiments for the performance evaluation. Experiments show that the proposed method leads to significant improvement of responsiveness, while retaining fairness.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.277-285
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• 2011

Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.

• Journal of Korea Multimedia Society
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• v.4 no.2
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• pp.130-135
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• 2001

When a networked virtual reality system handles composite media audio and video as well as three dimensional computer graphics, the quality of the virtual space is greatly affected by the current available network, and end system resources. Even if the network can preserve a certain amount of resources, the required resources change dynamically according to the user\`s navigation of a large virtual space, and then it may decrease the quality of the virtual space. In this paper, a method for resource allocation is proposed and the proposed system copes with the deterioration of quality of virtual spaces in case that the starvation of system resources occurs. The experimental results show that the proposed method is efficient.