• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1505-1516
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• 2001

The goal of Medical multimedia server is to develop computer hardware and software which would enable electronic access, storage, transmission, and display of patient data and images. Since the current network only provides so called "best-effort" services, it is impossible to satisfy QoS guarantee that is required for real time application services for emergency room, operating room etc. Accordingly, world-wide research is being made for a variety of services to provide QoS. he goal of DiffServ is to offer scalable differentiated service in Internet which are made possible by traffic classification and conditioning only performed at an edge(or a boundary) node. In case DiffServ was deployed in the Medical multimedia network, it is difficult to estimate how the QoS mechanism would affect totally the network performance. Therefore, we need to verify by simulation the design of algorithm which provide a variety of differentiated services. In QoS for Medical multimedia network, a simulator is designed and implemented using OPNET to investigate the performance of DiffServ QoS support mechanism. The developed DiffServ simulator may generate packets according to random, and bursty traffic models in order to incorporate diverse traffic conditions in the Medical multimedia network environment. Based on our simulation results, we confirmed that service differentiation is possible by using the EF(Expedited Forwarding) class in DiffServ networks.

• Journal of the Korean Professional Engineers Association
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• v.34 no.4
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• pp.41-47
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• 2001

The paper describes SR3 (Synchronous Round Robin with Reservations), a collision-free medium access control protocol for all-optical slotted packet networks based on WDM multi-channel ring topologies where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter SR3 is derived from the SRR and MMR protocols previously proposed by the same authors for the same class of all-optical networks. SRR and MMR already achieve an efficient exploitation of the available bandwidth, while guaranteeing a throughput-fair access to each node. SR3, In addition, allows nodes to reserve slots. thereby achieving a stronger control on access delays; it is thus well suited to meet tight delay requirements, as it is the case for multimedia applications. Simulation results show that SR3 provides very good performance to guaranteed qualify traffic, but also brings signigicant performance improvements for best-effort traffic. Energy effciency is an important issue for optical network since they must rely on their batteries. We present a novel MAC protocol that achieves a good energy efficiency of optical interface of the network and provides support for diverse traffic types and QoS. The scheduler of the base station is responsible to provide the required QoS to connections on the optical link and to minimise the amount of energy spend by the High speed Network. The main principles of the MaC protocol are to avoid unsuccessful actions, minimise the number of transitions , and synchronise the mobile and the base-station. We will show that considerable amounts of energy can be saved using these principles.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.66-71
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• 2012

In this paper, using the bargaining game theory, we propose a bandwidth management scheme that allocates bandwidth in an efficient and proportionally fair manner between the service classes with different service requirements. Since the traffic input rates of the classes are asymmetric in most of the time, the proposed scheme allocates bandwidth in proportion to the traffic input rates to increase the bandwidth utilization while protecting the quality of service of a class against the excessive traffic input of the other classes. In addition, the proposed method considers the weights of classes so that the bandwidth is allocated differentially among the classes.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.410-416
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• 2009

In recent years, the rollover accident of large class of vehicles has become important safety issue. Even though the rollover form a small percentage of all traffic accidents, they have a fatal effect upon the driver and passenger. Among the traffic accidents occurred in driving, the rollover is the major cause of traffic fatalities. Therefore, it is required to develop the analytical and experimental techniques for predicting rollover propensity of vehicles and also to improve the vehicle suspension design in the viewpoint of rollover resistance. In this study, the parameter sensitivities for the roll angle of SUV suspension are analyzed, and then the determined design parameters are optimized by using the regression model function of the response surface methods. The analysis results show that the roll angle of the optimized vehicle is decreased as compared with the initial vehicle and also the rollover possibility is decreased when the roll rate of the front suspension is larger than the roll rate of the rear suspension.

• Convergence Security Journal
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• v.7 no.2
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• pp.39-47
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• 2007

The scheduling algorithms to provide quality of service (QoS) in broadband convergence network (BcN) are compared and analysed. The main QoS management methods such as traffic classification, traffic processing in the input queue and weighted queueing are first analysed, and then the major scheduling algorithms of round robin, priority and weighted round robin under recently considering for BcN to supply real time multimedia communications are analysed. The simulation results by NS-2 show that the scheduling algorithm with proper weights for each traffic class outperforms the priority algorithm.

• Journal of Communications and Networks
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• v.9 no.3
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• pp.330-341
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• 2007

This work analyzes the performance of the parallel packet switch (PPS) with a sliding window (SW) method. The PPS involves numerous packet switches that operate independently and in parallel. The conventional PPS dispatch algorithm adopts a round robin (RR) method. The class of PPS is characterized by deployment of parallel low-speed switches whose all memory buffers run more slowly than the external line rate. In this work, a novel SW packet switching method for PPS, called SW-PPS, is proposed. The SW-PPS employs memory space more effectively than the existing PPS using RR algorithm. Under identical Bernoulli and bursty data traffic, the SW-PPS provided significantly improved performance when compared to PPS with RR method. Moreover, this investigation presents a novel mathematical analytical model to evaluate the performance of the PPS using RR and SW method. Under various operating conditions, our proposed model and analysis successfully exhibit these performance characteristics including throughput, cell delay, and cell drop rate.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.221-226
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• 2002

Cycling Packet Dropping mechanism we proposed in this paper adaptively drops packets, as predicting traffic pattern between each cycle. Therfore the proposed mechanism makes up for the drawback of RIO mechanism and minimizes errors being capable of predicting in Dynamic and Strict Packet Dropping mechanism. And we executed a simulation and analyzed the throughput and packet drop rate based on the Sending Drop Precedence changing dynamically depending on the network traffic. The results show that the proposed mechanism provides better performance on drop precedence levels and stricter drop precedence policy for AF class.

• International Journal of Advanced Culture Technology
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• v.10 no.2
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• pp.300-306
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• 2022

Currently, Korea is building traffic infrastructure using Intelligent Transport Systems (ITS), but the pedestrian traffic accident rate is very high. The purpose of this paper is to prevent the risk of traffic accidents by jaywalking pedestrians. The development of this study aims to detect pedestrians who trespass using the public data set provided by the Artificial Intelligence Hub (AIHub). The data set uses training data: 673,150 pieces and validation data: 131,385 pieces, and the types include snow, rain, fog, etc., and there is a total of 7 types including passenger cars, small buses, large buses, trucks, large trailers, motorcycles, and pedestrians. has a class format of Learning is carried out using YOLOv5 as an implementation model, and as an object detection and edge detection method of an input image, a canny edge model is applied to classify and visualize human objects within the detected road boundary range. In this study, it was designed and implemented to detect pedestrians using the deep learning-based YOLOv5 model. As the final result, the mAP 0.5 showed a real-time detection rate of 61% and 114.9 fps at 338 epochs using the YOLOv5 model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11B
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• pp.960-968
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• 2006

HMIPv6 improved the handover management of basic MIPv6 by introducing the new protocol agent MAP. In this new protocol, MAP instead of the Mobile Node intercepts all packets and redirects the packets to CoA of the Mobile Node. However, this process may degrade the network performance due to the centralization phenomenon of registration occurring in the hierarchical MAP structure. ffe propose two schemes to improve real time traffic performance. First proposal is a MAP selection mettled in which MAP is selected based on traffic characteristics. And we also propose differentiated traffic processing scheme with multi-level queues when Home Agent or Correspondent Nodes process Binding Update messages. Performances of the proposed scheme are analyzed. Analysis result shows that our model has good performance in the respect of location update cost and total cost of Mobile Nodes.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.748-755
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• 2015

In this paper, sharing based admission control scheme is suggested for both service differentiation and improvement of wavelength utilization efficiency in burst switching networks. To provide service differentiation and high wavelength utilization efficiency, some of the wavelengths on a output link are shared with all classes and the others are used for the highest class exclusively. Markov based analysis is applied to the suggested scheme for the performance analysis and the numerical results are derived. The results are: The performance of lower traffic is more improved by the more number of shared wavelengths in case that the higher traffic or lower traffic is arrived equally or that the input rate of lower traffic is low. Another result is that the sharing effect of wavelengths is a little bit lowered when lower traffic passes the threshold.