• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.171-172
• /
• 2008

We propose the sensor networks middleware based on publish/subscribe model for adaptive service to client. Publish/subscribe middleware make capability of sensor to data through the advertisement message. Based on capability of sensor, Publish/subscribe middleware adaptively service to client. And client make a collection of information that it require. Therefore middleware service more effectively.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.11C
• /
• pp.33-42
• /
• 2001

We consider a model describing large scale performance of multiservice networks supporting both constant- and adaptive-rate services. As the number of constant-rate connection changes over time in multiservice networks, the available bandwidth for adaptive-rate connections changes as well. We estimate the available bandwidth for adaptive-rate service in a dynamically changing traffic environment based on Erlang fixed point equation and Little\`s law. The bandwidth allocation for adaptive-rate service is determined by the max-min fairness criterion. We find an upper bound on the average minimum throughput for adaptive-rate service, and 7how that the bound is achieved in large-capacity networks. This is verified using network examples. Since max-min fair allocation may not maximize the total throughput or revenue in a network, we consider adjustments via network level priority schemes to increase efficiency.

• Journal of Korea Multimedia Society
• /
• v.10 no.12
• /
• pp.1622-1631
• /
• 2007

To realize the wireless packet scheduler which efficiently considers both the effect of adaptive modulation and coding (AMC) scheme due to variable wireless communication channel information from physical layer and the QoS differentiation of multimedia services from internet protocol (IP) layer, this paper proposes a new downlink AMC-based priority queuing (APQ) scheduler which combines AMC scheme and service priority method in multimedia services at the same time. The result of numerical analysis shows that the proposed APQ algorithm plays a role in increasing the number of services satisfying the mean waiting time requirements per each service in multimedia services because the APQ scheme allows the mean waiting time of each service to be reduced much more than existing packet scheduler having only user selection processor.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.3A
• /
• pp.261-270
• /
• 2007

The Delay Threshold-based Priority Queueing (DTPQ) scheme has been shown useful for scheduling both real-time (RT) and non-real-time (NRT) service traffic in mobile broadband wireless access (MBWA) systems. The overall system capacity can be maximized subject to their QoS requirement by the DTPQ scheme, which takes the urgency of the RT service into account only when their head-of-line (HOL) packet delays exceed a given delay threshold. In practice, the optimum delay threshold must be configured under the varying service scenarios and a corresponding traffic load, e.g., the number of RT and NRTusers in the system. In this paper, we propose an adaptive version of DTPQ scheme, which updates the delay threshold by taking the urgency and channel conditions of RT service users into account. By evaluating the proposed approach in an orthogonal frequency division multiple access/time division duplex (OFDM/TDD)-based broadband mobile access system, it has been found that our adaptive scheme significantly improves the system capacity as compared to the existing DTPQ scheme with a fixed delay threshold.

• Journal of Korea Multimedia Society
• /
• v.9 no.4
• /
• pp.460-469
• /
• 2006

Recently, a demand of adaptive multimedia service, which supports multimedia service migration according to user's location and characteristics of user device, is increased. In this paper, we propose a service migration system, which becomes aware of user device using intelligent agent. And we design and implement the ontology-based intelligent agent, which is aware of the context in its environment. Moreover, we implement a context reasoning system using location information.

• The KIPS Transactions:PartD
• /
• v.12D no.6 s.102
• /
• pp.899-904
• /
• 2005

Necessity of the service-on-demand that reflect a personal characteristic of a customer was increased by an aggravation of web service competition. So a study on a customization is being performed actively. The common customization system supporting of the personalization is performed through the computational data like individual characteristic or preference. Various studies on the service that used emotional information were performed. But we can't use this emotional information in the web system because of characteristics of emotional information system In this study, we design the adaptive customization system that used emotional information of the customer and analyse the system by experiments.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.1
• /
• pp.83-89
• /
• 2010

If an appliance perceives the location or health condition of a resident in the smart home, it can provide more intelligent service actively. That is, while the conventional appliance is operated by manual input of a resident, the location-based human adaptive appliance detects the resident's information such as location, activity pattern, or health condition by itself and provides the most suitable living condition for the resident autonomously. This paper presents the real-time location-based metabolic rate estimation method that measures the amount of physical activity (metabolic rate) for location-based human adaptive air-conditioner. And, the feasibility of the algorithm is evaluated experimentally on a test bed using the pyroelectric infrared sensor-based indoor location aware system (PILAS) that is a non-terminal-based location-aware system.

• Journal of Korean Library and Information Science Society
• /
• v.32 no.4
• /
• pp.229-256
• /
• 2001

Library service should be available and accessible to every one. But people with disabilities were much excluded from library and information service in Korea. The information and communications revolution ought to be a passport to inclusiveness the disabled in library and information service. This study describes current library services for the visually handicapped and reviews related critical issues in Korea and the state of the art in adaptive technology for low vision and blindness. And proposes necessary methods to improve library and information services for the visually handicapped in Korea.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.8
• /
• pp.3551-3567
• /
• 2016

The Low Earth Orbit satellite network has the unique characteristics of the non-uniform and time-variant traffic load distribution, which often causes severe link congestion and thus results in poor performance for delay-sensitive flows, especially when the network is heavily loaded. To solve this problem, a novel adaptive routing algorithm, referred to as the delay-oriented adaptive routing algorithm (DOAR), is proposed. Different from current reactive schemes, DOAR employs Destination-Sequenced Distance-Vector (DSDV) routing algorithm, which is a proactive scheme. DSDV is extended to a multipath QoS version to generate alternative routes in active with real-time delay metric, which leads to two significant advantages. First, the flows can be timely and accurately detected for route adjustment. Second, it enables fast, flexible, and optimized QoS matching between the alternative routes and adjustment requiring flows and meanwhile avoids delay growth caused by increased hop number and diffused congestion range. In addition, a retrospective route adjustment requesting scheme is designed in DOAR to enlarge the alternative routes set in the severe congestion state in a large area. Simulation result suggests that DOAR performs better than typical adaptive routing algorithms in terms of the throughput and the delay in a variety of traffic intensity.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.5
• /
• pp.2544-2557
• /
• 2019

Adaptive bitrate streaming is a crucial element in the implementation of high-quality streaming of media content over the Internet. Dynamic adaptive streaming over HTTP (MPEG-DASH) has lately emerged as the de facto solution for over-the-top (OTT) video streaming services. In this paper, we perform macro-level analysis on a real-world MPEG-DASH-based Internet live broadcasting service to gain insight into its behavior throughout the end-to-end service-provision chain, from broadcasters to viewers. Based on this analysis, we propose methods to improve the quality-of-experience (QoE) of MPEG-DASH-based services, particularly with regard to reducing broadcasting delays between recording and viewing of videos, as well as synchronizing client terminals.