• Title/Summary/Keyword: queuing

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Design Algorithm & Datagram Analysis of UDP using Queuing (Queuing을 이용한 UDP 설계 알고리즘과 데이터그램 분석)

  • Eom, Gum-Yong
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.231-233
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    • 2004
  • Queuing is waiting lines which play routing service when packet entered. Queuing is decide how and whom is going to provide priority service. This is kind of first in first out(FIFO) or weighted fair queuing(WFQ) method. In this study, UDP design using WFQ way to serve to provide service evenly and rapidly in network. Also in actuality internet, datagram analyzed by packet captured. Queuing services through the requesting port number, input, output, output queuing creation & delete, message request by internet control message protocol(ICMP). Queuing designed in control block module, input queues, input/output module composition. In conclusion, I have confirm queuing result of WFQ method by the datagram information analyzed.

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A Fair Queuing Algorithm to Reduce Energy Consumption in Wireless Channels (무선 채널의 에너지 소비를 줄이기 위한 공평 큐잉 알고리즘)

  • Kim, Tae-Joon
    • Journal of Korea Multimedia Society
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    • v.10 no.7
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    • pp.893-901
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    • 2007
  • Since real-time multimedia applications requiring duality-of-service guarantees are spreading over mobile and wireless networks, energy efficiency in wireless channels is becoming more important. Energy consumption in the channels can be reduced with decreasing the rate of scheduler's outgoing link by means of Dynamic Modulation Scaling (DMS). This paper proposes a fair queuing algorithm, termed Rate Efficient Fair Queuing (REFQ), in order to reduce the outgoing link's rate, which is based on the Latency-Optimized Fair Queuing algorithm developed to enhance Weighted Fair Queuing (WFQ). The performance evaluation result shows that REFQ does decrease the link rate by up to 35% in comparison with that in WFQ, which results in reducing the energy consumption by up to 90% when applied to the DMS based radio modem.

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A studying example on simulation of the Queuing system of the window Box (窓口Queuing System의 Simulation에 관한 事例 硏究)

  • 양해술
    • Communications of the Korean Institute of Information Scientists and Engineers
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    • v.5 no.2
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    • pp.49-60
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    • 1987
  • To decide on the queuing system of the optimum-sized bank window, data by means of simulation was reckoned. That is, by linking the average arrival rate and the average service rate with the exponential random number, customers' arrival time and service time was reckoned and simulation size optionally decided. By so doing, this paper is aimed at predicting the conditions of a bank, average arrival time, average waiting time, aveerage service time, average queuing length, servers' idle time, etd, and at preparing for a simulation model of the queuing system that can apply not only to the bank window box but also to all system under which queuing phenomena may arise.

Analysis of queuing mine-cars affecting shaft station radon concentrations in Quzhou uranium mine, eastern China

  • Hong, Changshou;Zhao, Guoyan;Li, Xiangyang
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.453-461
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    • 2018
  • Shaft stations of underground uranium mines in China are not only utilized as waiting space for loaded mine-cars queuing to be hoisted but also as the principal channel for fresh air taken to working places. Therefore, assessment of how mine-car queuing processes affect shaft station radon concentration was carried out. Queuing network of mine-cars has been analyzed in an underground uranium mine, located in Quzhou, Zhejiang province of Eastern China. On the basis of mathematical analysis of the queue network, a MATLAB-based quasi-random number generating program utilizing Monte-Carlo methods was worked out. Extensive simulations were then implemented via MATALB operating on a DELL PC. Thereafter, theoretical calculations and field measurements of shaft station radon concentrations for several working conditions were performed. The queuing performance measures of interest, like average queuing length and waiting time, were found to be significantly affected by the utilization rate (positively correlated). However, even with respect to the "worst case", the shaft station radon concentration was always lower than $200Bq/m^3$. The model predictions were compared with the measuring results, and a satisfactory agreement was noted. Under current working conditions, queuing-induced variations of shaft station radon concentration of the study mine are not remarkable.

A study on Improving Latency-Optimized Fair Queuing Algorithm (최적 레이턴시 기반 공정 큐잉 방식의 개선에 관한 연구)

  • Kim, Tae-Joon
    • Journal of Korea Multimedia Society
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    • v.10 no.1
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    • pp.83-93
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    • 2007
  • WFQ (Weighted Fair Queuing) is the most popular fair queuing algorithm, but it had the inherent drawback of a poet bandwidth utilization, particularly under the traffic requiring a low rate but tight delay bound such as internet phone. It was recently identified that the poor utilization is mainly due to the non-optimized latency of a flow and then LOFQ(Latency-Optimized Fair Queuing) to overcome the drawback was introduced. In this paper, we improve the performance of LOFQ by introducing an occupied resource optimization function and reduce the implementation complexity of recursive resource transformation by revising the transformation scheme. We also prove the superiority of LOFQ over WFQ in terms of utilization. The simulation result shows that the improved LOFQ provides $20{\sim}30%$ higher utilization than that in the legacy LOFQ.

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Total Resource Requirements-Based Priority Queuing Scheme for DS/CDMA Cellular Networks

  • Piao, Shiquan;Park, Jae-Won;Park, Yong-Wan
    • ETRI Journal
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    • v.28 no.3
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    • pp.371-374
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    • 2006
  • We propose and analyze a priority queuing scheme that gives priority in the same class of calls according to their total resource requirements (TRRs). The proposed scheme gives a higher priority to the calls that have a lower TRR over the calls that have a higher TRR. The numerical results show that the proposed priority queuing scheme provides better performance than the traditional queuing schemes in call blocking probability.

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An Efficient Scheduling Algorithm for Internet Traffic over ATM Network (ATM 망에서 인터넷 트래픽을 서비스하기 위한 효율적인 스케줄링 알고리즘에 관한 연구)

  • Kim, Kwan-Woong;Bae, Sung-Hwan;Chon, Byoung-Sil
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.9
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    • pp.12-19
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    • 2002
  • Guaranteed Frame Rate(GFR) service is intended to efficiently support TCP/IP traffic in ATM networks. The GFR service not only guarantees a minimum service rate at the frame level, but also supports a fair share of available bandwidth. The original GFR proposal outlined two switch implementation scheme : FIFO Queuing and perVC-Queuing. In general, it has been shown that FIFO Queuing is not sufficient to provide rate guarantees and perVC-Queuing with scheduling is needed. In perVC-Queuing implementation, scheduling algorithm plays key rule to provide rate guarantees and to improve fairness. We proposed a new scheduling algorithm for the GFR service. Proposed algorithm can provide minimum service rate guarantee and fair sharing to GFR VCs. Computer simulation results show that proposed scheduling scheme provide a much better performance in TCP Goodput and fairness than previous scheme.

Impact Evaluation of DDoS Attacks on DNS Cache Server Using Queuing Model

  • Wang, Zheng;Tseng, Shian-Shyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.4
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    • pp.895-909
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    • 2013
  • Distributed Denial-of-Service (DDoS) attacks towards name servers of the Domain Name System (DNS) have threaten to disrupt this critical service. This paper studies the vulnerability of the cache server to the flooding DNS query traffic. As the resolution service provided by cache server, the incoming DNS requests, even the massive attacking traffic, are maintained in the waiting queue. The sojourn of requests lasts until the corresponding responses are returned from the authoritative server or time out. The victim cache server is thus overloaded by the pounding traffic and thereafter goes down. The impact of such attacks is analyzed via the model of queuing process in both cache server and authoritative server. Some specific limits hold for this practical dual queuing process, such as the limited sojourn time in the queue of cache server and the independence of the two queuing processes. The analytical results are presented to evaluate the impact of DDoS attacks on cache server. Finally, numerical results are provided for further analysis.

USE OF AN ORTHOGONAL PROJECTOR FOR ACCELERATING A QUEUING PROBLEM SOLVER

  • Park, Pil-Seong
    • Journal of applied mathematics & informatics
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    • v.3 no.2
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    • pp.193-204
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    • 1996
  • Overflow queuing models are ofter analyzed by explicitly solving a large sparse singular linear systems arising from Kolmogorov balance equation. The system is often converted into an eigenvalue problem the dominant eigenvector of which is the desired null vector. In this paper we convert an overflow queuing problem the dominant eigenvector of which is the desired null vector. In this paper we convert an overflow queuing problem into an overflow queuing problem into an eigen-value problem into an eigen-value problem of size 1/2 of the original. Then we devise an orthogonal projector that enhances its convergence by removing unsanted eigen-components effectively. Numerical result with some suggestion is given at the end.

Multi-Objective Soft Computing-Based Approaches to Optimize Inventory-Queuing-Pricing Problem under Fuzzy Considerations

  • Alinezhad, Alireza;Mahmoudi, Amin;Hajipour, Vahid
    • Industrial Engineering and Management Systems
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    • v.15 no.4
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    • pp.354-363
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    • 2016
  • Due to uncertain environment, various parameters such as price, queuing length, warranty, and so on influence on inventory models. In this paper, an inventory-queuing-pricing problem with continuous review inventory control policy and batch arrival queuing approach, is presented. To best of our knowledge, (I) demand function is stochastic and price dependent; (II) due to the uncertainty in real-world situations, a fuzzy programming approach is applied. Therefore, the presented model with goal of maximizing total profit of system analyzes the price and order quantity decision variables. Since the proposed model belongs to NP-hard problems, Pareto-based approaches based on non-dominated ranking and sorting genetic algorithm are proposed and justified to solve the model. Several numerical illustrations are generated to demonstrate the model validity and algorithms performance. The results showed the applicability and robustness of the proposed soft-computing-based approaches to analyze the problem.