• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.10
• /
• pp.16-23
• /
• 2003

In this paper, we propose a new optical hybrid switching system that takes advantage of both Optical Burst Switching (OBS) and Optical Circuit Switching (OCS) technologies. This system classifies incoming IP traffic flows into short-lived and long-lived flows for hybrid switching. For performance analysis, we model the system as a single server queue in a Markovian environment. The burst generation process is assumed to follow a two-state Markov Modulated Poisson Process (MMPP), and the service rate fluctuates based on the number of concurrent OCS sessions. Results of the mean delay and queue size for OBS bursts are derived.

• Journal of the Institute of Convergence Signal Processing
• /
• v.12 no.2
• /
• pp.102-106
• /
• 2011

The transfer capability of HFC (Hybrid Fiber Coax) network is superior to xDSL. HFC network, however, is not suitable for transferring high quality video due to cable model interfaces. For the services of high quality IPIV or VOD, the extra exclusive downstream transfer system is required without upgrading pre-equipped cable modem and service capability. This paper is aimed to develop the extra exclusive downstream transfer system not changing existing cable modem system but providing same quality of services. This system is composed of the extra exclusive downstream IP-cable sender and modem. This sender and modem have 30 Mbps transfer capability and HDTV stream can be served in the Cable TV network using 21 Mbps HDTV transport stream.

• Journal of IKEEE
• /
• v.10 no.1 s.18
• /
• pp.75-86
• /
• 2006

The MANET that can make autonomous distributed Network with Routing function has many differences than past wireless communication. For upcoming ALL-IP environment, MANET device should be connected with wired Internet Network and MANET is required to have a gateway to bridge two different networks to share information from any place. In this paper, Using the GMAHN Algorithm proposed Proactive, Reactive, Hybrid method that provides Inteface between Wired Internet network and MANET, we learned each method's the advantage and disadvantage through the various network environments. And also, we presented the optimization method of Hybrid combined Proactive with Reactive.

• Journal of KIISE
• /
• v.42 no.7
• /
• pp.939-945
• /
• 2015

From 2009, the market of smart devices has been rapidly increasing. These devices provide various services to users. The cloud messaging service, especially, is applied to many various services, and sends messages asynchronously. In the cloud messaging service, there are two methods for message transmission, message transmission based on an IP address and a publish/subscribe technique. Each technique uses basic messages in order to send messages to mobile devices. In this paper, the hybrid message transmission, based on user-customized analysis to reduce basic messages, is proposed. The hybrid message transmission uses Exponential Moving Average (EMA) and K-means algorithms for user-customized analysis, and determines the message transmission techniques in each timeslot.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.5
• /
• pp.345-353
• /
• 2003

When designing network processors or implementing network equipments such as routers are implemented, IP lookup operations cause the major impact on their performance. As the organization of the IP address becomes simpler, the speed of the IP lookup operations can go faster. However, since the efficient management of IP address is inevitable due to the increasing number of network users, the address organization should become more complex. Therefore, for both IPv4(IP version 4) and IPv6(IP version 6), it is the essential fact that IP lookup operations are difficult and tedious. Lots of researcher for improving the performance of IP lookups have been presented, but the good solution has not been came out. Software approach alleviates the memory usage, but at the same time it si slow in terms of searching speed when performing an IP lookup. Hardware approach, on the other hand, is fast, however, it has disadvantages of producing hardware overheads and high memory usage. In this paper, conventional researches on IP lookups are shown and their advantages and disadvantages are explained. In addition, by mixing two representative structures, a new hybrid parallel architecture for fast IP lookups is proposed. The performance evaluation result shows that the proposed architecture provides better performance and lesser memory usage.

• Steel and Composite Structures
• /
• v.45 no.2
• /
• pp.159-173
• /
• 2022

This paper proposes a hybrid machine-learning model, which is called DANN-IP, that combines a deep artificial neural network (DANN) and an interior-point (IP) algorithm in order to improve the prediction capacity on the patch loading resistance of steel plate girders. For this purpose, 394 steel plate girders that were subjected to patch loading were tested in order to construct the DANN-IP model. Firstly, several DANN models were developed in order to establish the relationship between the patch loading resistance and the web panel length, the web height, the web thickness, the flange width, the flange thickness, the applied load length, the web yield strength, and the flange yield strength of steel plate girders. Accordingly, the best DANN model was chosen based on three performance indices, which included the R^2, RMSE, and a20-index. The IP algorithm was then adopted to optimize the weights and biases of the DANN model in order to establish the hybrid DANN-IP model. The results obtained from the proposed DANN-IP model were compared with of the results from the DANN model and the existing empirical formulas. The comparison showed that the proposed DANN-IP model achieved the best accuracy with an R^2 of 0.996, an RMSE of 23.260 kN, and an a20-index of 0.891. Finally, a Graphical User Interface (GUI) tool was developed in order to effectively use the proposed DANN-IP model for practical applications.

• ETRI Journal
• /
• v.38 no.5
• /
• pp.838-846
• /
• 2016

The objective of digital broadcasting has evolved from providing a plain video service to offering a realistic visual experience. Technologies such as 3DTV and UHDTV have been suggested to achieve this new objective by providing an immersive and stereoscopic visual experience. However, owing to the high bandwidth requirements of such services, the broadcasting industry has faced a challenge to find a new transport mechanism for overcoming the bandwidth limitation. The standardization organizations, the Advanced Television Systems Committee, Digital Video Broadcasting, and Telecommunications Technology Association, have been working on the integration of broadcasting and a broadband network (IP) to resolve the bandwidth issue of realistic video services. This paper introduces a frame-level timeline synchronization and transport system target decoder model for providing a stable 3DTV service over a hybrid network. The experimental results indicate that the proposed technologies can be successfully adopted as a reference model in a broadcast-broadband hybrid 3DTV service and other IP-associated hybrid broadcasting services.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.10B
• /
• pp.630-638
• /
• 2005

As real-time media applications based on IP multicast networks spread widely, the end-to-end QoS (quality of service) provisioning for these applications have become very important. To guarantee the end-to-end QoS of multi-party media applications, it is essential to monitor the time-varying status of both network metrics (i.e., delay, jitter and loss) and system metrics (i.e., CPU and memory utilization). In this paper, targeting the multicast-enabled AG (Access Grid) group collaboration tool based on multi-Party real-time media services, a hybrid monitoring scheme that can monitor the status of both multicast network and node system is investigated. It combines active monitoring and passive monitoring approaches to measure multicast network. The active monitoring measures network-layer metrics (i.e., network condition) with probe packets while the passive monitoring checks application-layer metrics (i.e., user traffic condition by analyzing RTCP packets). In addition, it measures node system metrics from system API. By comparing these hybrid results, we attempt to pinpoint the causes of performance degradation and explore corresponding reactions to improve the end-to-end performance. The experimental results show that the proposed hybrid monitoring can provide useful information to coordinate the performance improvement of multi-party real-time media applications.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.6
• /
• pp.512-517
• /
• 2018

Improving voice quality is a major concern in telecommunications. In this paper, we propose a robust speech quality enhancement against background noise and packet loss at VoIP (Voice-over-IP) receiver. The proposed method combines network jitter estimation based on hybrid Markov chain, adaptive playout scheduling using the estimated jitter, and speech enhancement based on restoration of amplitude and phase to enhance the quality of the speech signal arriving at the VoIP receiver over IP network. The experimental results show that the proposed method removes the background noise added to the speech signal before encoding at the sender side and provides the enhanced speech quality in an unstable network environment.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.7 s.349
• /
• pp.150-155
• /
• 2006

A hybrid Ad-hoc network connected to the Internet needs an IP address configuration to communicate with the Internet. Most of proposed address autoconfiguration algorithms are node based. The node based address autoconfiguration algorithms waste bandwidth and consume much battery in mobile ad-hoc networks. In this paper, we propose the address allocation algorithm in hybrid Mobile ad-hoc network (MANET). The proposed algorithm reduces network traffic by transferring address configuration packet to the internet gateway by unicast method. Moreover, our IP address configuration algorithm also reduces battery consumption and address configuration time by decreasing number of configuration packets on internet gateway.