• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.812-822
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• 1997

In this paper, we propose an architecture of the asynchronous shared-bus type switch with priority and fairness schemes. The switch architecture is an input and output queueing system, and the priority scheme is implemented in both input and output queues. We analyze packet delay of both input and output queues. In the analysis, we consider to stations with asymmetric arrival rates. Although we make some approximations in the analysis, the numerical results show good agreements with the simulation results.

• Journal of Computing Science and Engineering
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• v.9 no.2
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• pp.108-117
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• 2015

Interrupt handling is generally separated from process scheduling. This can lead to a scheduling anomaly and priority inversion. The processor can interrupt a higher priority process that is currently executing, in order to handle a network packet reception interruption on behalf of its intended lower priority receiver process. We propose a new network interrupt handling scheme that combines interrupt handling with process scheduling and the priority of the process. The proposed scheme employs techniques to identify the intended receiver process of an incoming packet at an earlier phase. We implement a prototype system of the proposed scheme on Linux 2.6, and our experiment results show that the prototype system supports the predictable real-time behavior of higher priority processes even when excessive traffic is sent to lower priority processes.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.881-892
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• 1999

In this paper we consider a polling system with two classes of stations; high priority and low priority. High priority stations are polled more frequently than low priority stations. We derive an exact and explicit formula for computing the mean waiting times for a message when the arrival processes are batch Poisson. In general the formula requires to solve two sets of simultaneous equations By specializing them to the case of two priority classes we greatly reduce the number equations and provide a simple formula for mean waiting times. We apply the results to a data communication processing system and show that the overall mean waiting time can be reduced by using priority polling.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.149-159
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• 2011

In this paper, we study the problem of how to design a medical-grade wireless local area network (WLAN) for healthcare facilities. First, unlike the IEEE 802.11e MAC, which categorizes traffic primarily by their delay constraints, we prioritize medical applications according to their medical urgency. Second, we propose a mechanism that can guarantee absolute priority to each traffic category, which is critical for medical-grade quality of service (QoS), while the conventional 802.11e MAC only provides relative priority to each traffic category. Based on absolute priority, we focus on the performance of real-time patient monitoring applications, and derive the optimal contention window size that can significantly improve the throughput performance. Finally, for proper performance evaluation from a medical viewpoint, we introduce the weighted diagnostic distortion (WDD) as a medical QoS metric to effectively measure the medical diagnosability by extracting the main diagnostic features of medical signal. Our simulation result shows that the proposed mechanism, together with medical categorization using absolute priority, can significantly improve the medical-grade QoS performance over the conventional IEEE 802.11e MAC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1884-1892
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• 1993

In push out scheme, high priority cell which arrives when the buffer is full pushs low priority cell. The PBS scheme provides priority by variable threshold in buffer.In this paper, for Controlling congestion in ATM network we propose buffer processing method in which the PBS scheme has variable threshold. And we analysis The performance of this scheme. As a result of simulation, the proposed push out scheme with variable threshold reduces the loss of low priority cell compared with existing push out scheme. This proposed method not only reduces the loss of high priority cell like existing push out scheme but also reduces the loss of low priority cell by variable threshold.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.102-105
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• 2010

Traditional Pub/Sub(Publish/Subscribe) Systems search all subscriptions that match an incoming event by broker(i.e. it is not considering the accuracy of matching between an incoming event and subscriptions and only consider that an event either matches a subscription or not). However, subscriptions that match an event may have priority, therefore, we need priority Pub/Sub system. In this paper, we define what the accuracy means in order to prioritize among subscriptions and propose the Priority Retrieval Technique based on accuracy that able to search subscriptions. The Priority Retrieval Technique is based on IS-Lists. We can search the results ordered by accuracy.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.4
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• pp.81-93
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• 2000

It is important to find the competitive priority, which makes a great contribution to the action plans. The reason is that this makes it possible to provide Korean manufacturers with effective behavioral model to break through the depression after 1997'financial crisis in Korea. Focused priority has become a focus of organizations faced with the need to survive in a highly uncertain business environment characterized by rapid technological change, global competition, and demanding customers. Many believe that better linkages of priority and action plans are fundamental to surviving in the world market. However, there was little previous research dealing with the relationship between the strategic priority and action plans in the view of competitive weapon. This study presents empirical findings on differences between U.S. and Korean manufacturing approach to relationship of priority and plans. Specially, Korean manufacturers are eager for good model to overcome depression of 1997' financial crisis in Korea. Data was collected as part of the Manufacturing Futures Project completed in 1996. The results indicate that U.S. manufacturers maintain focused linkages from priority to action plans than do Korean manufacturers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.369-373
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• 1989

This paper investigates average access times on eight asynchronous priority levels of FDDI MAC protocol with parameters on offered loads, message sizes, and number of stations. In case of parameter with offered loads, higher priority levels exhibit similar variances and in case of parameter with message sizes and number of satations, higher priority levels exhibit almost invariables but as increase of message sizes, increase only a small amount of access time on the other hand, as number of stations increase, average access times decrease little by little. But in case of lowest priority level. average access times decrease little by little. But in case of lowest priority level, average access times exhibit relatively large variances about above three parameters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1840-1850
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• 1998

In this paper, we propose a priority control algorithm using hop count, called HC-PC(Priority Control Algorithm using Hop-Count) for steaming mode CLS, in wide area ATM networks. In our HC-PC algorithm, hop count of packet is increased by one as traverse CLS hop and is used as loss priority when a CLS buffer is congested. That guards packets with higher priority form congestion. The average packet loss probabilities are evaluated via mathematical analysis for HC-PC algorithm case and no priority control case. The simulationresults indicate that our algorithm may offer better performance in terms of loss fairness for pathe length and yield high utilization of newtork resource.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.459-466
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• 1999

I broadband ISDN every packet will show different result if it would be processed according to its usage by the server. That is, normal data won't show big differences if they would be processed at normal speed. But it will improve the quality of service to process some kinds of data - for example real time video or voice type data or some data for a bid to by something through the internet - more fast than the normal type data. solution for this problem was suggested - priority packets. But the analyses of them are under way. Son in this paper a switching system for an output queuing model in a single server was assumed and some packets were given priorities and analysed. And correlation, simulating real life situation, was given too. These packets were analysed through three cases, first packets having no correlation, second packets having only correlation and finally packets having priority three cases, first packets having no correlation, second packets having only correlation and finally packets having priority and correlation. The result showed that correlation doesn't affect the mean delay time and the high priority packets have improved mean delay time regardless of the arrival rate. Those packets were assumed to be fixed-sized like ATM fixed-sized cell and the contention strategy was assumed to be short bus contention method for the output queue, and the mean delay length and the maximum 버퍼 length not to lose any packets were analysed.