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Study of Asymmetric Polling System with Two Message Classes
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作者 曹春生 张卫东 《Journal of Beijing Institute of Technology》 EI CAS 2007年第2期182-186,共5页
A novel mixed polling system with multiple stations is considered. Each station produces two classes of messages served with different disciplines. The real time message served with exhaustive service discipline and t... A novel mixed polling system with multiple stations is considered. Each station produces two classes of messages served with different disciplines. The real time message served with exhaustive service discipline and the unreal time message served with gated service discipline. Using an iterative method, the exact mean waiting times for both message classes are derived. The influence of the gate location of the message class served by the gated service discipline on the mean waiting time is also analyzed. The analytical results are verified with simulation method and agree well with simulation results. 展开更多
关键词 mean waiting time message class gate location polling system
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PERFORMANCE ANALYSIS OF POLLING SYSTEMS WITH LIMITED SERVICE 被引量:12
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作者 Zhao Dongfeng Li Bihai Zheng Sumin(Department of Information and Electronic Science, Yunnan University, Kunming 650091) 《Journal of Electronics(China)》 1998年第1期43-49,共7页
This paper analyzes a queue mode] of the polling system with limited service (K=1) in discrete time. By the imbedded Markov chain theory and the probability generating function method, the mean values of queue length ... This paper analyzes a queue mode] of the polling system with limited service (K=1) in discrete time. By the imbedded Markov chain theory and the probability generating function method, the mean values of queue length and message waiting time are explicitly obtained. Also, we give the simulation results. The results obtained by H. Tagai (1985) are revised. 展开更多
关键词 polling system LIMITED SERVICE DISCRETE TIME
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Characteristics of a Two-Class Polling System Model 被引量:4
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作者 Zhijun Yang Hongwei Ding 《Tsinghua Science and Technology》 SCIE EI CAS 2014年第5期516-520,共5页
Polling system models have a wide range of important applications including time-sharing computer systems, industrial control, communications, and computer networks. In this paper, we propose a two-class priority- bas... Polling system models have a wide range of important applications including time-sharing computer systems, industrial control, communications, and computer networks. In this paper, we propose a two-class priority- based polling system that uses gated and exhaustive services to achieve the priority-based scheme. This model is set up according to the method of the imbedded Markov chain theory and the generation function and explicitly analyzes key system performance characteristics including mean queue length, cyclic time, and throughput. Theoretical and simulation results are identical and demonstrate the efficiency of the model. 展开更多
关键词 polling system priority-based scheme gated service exhaustive service
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CORBA异步Polling模型的研究与实现
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作者 张志伟 杨玉清 +1 位作者 杨大强 吴泉源 《计算机工程》 CAS CSCD 北大核心 2004年第7期6-7,110,共3页
基于CORBA异步消息中的抽象Polling模型提出了一种Polling模型实现方案,讨论了其中的核心算法,该算法能分解耦合请求和应答并确保at-most-once语义。在分布对象中间件平台StarBus上实现了该模型和算法,实现结果表明该模型和算法为在C... 基于CORBA异步消息中的抽象Polling模型提出了一种Polling模型实现方案,讨论了其中的核心算法,该算法能分解耦合请求和应答并确保at-most-once语义。在分布对象中间件平台StarBus上实现了该模型和算法,实现结果表明该模型和算法为在CORBA中实现异步Polling机制提供了一种有效的参考方案。 展开更多
关键词 分布对象中间件 异步机制 polling模型
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Polling规约的远动实时数据的接收
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作者 梁京章 苏东伟 《软件》 北大核心 1996年第10期38-41,45,共5页
在电力系统MIS开发建设中,远动实时信息经加工后进入管理信息网是一项基本功能要求。实时信息进入管理信息网,首先要解决如何从远动系统接收数据的问题。本文结合“广西西津电厂远动实时信息网络监视系统”的开发,介绍如何实现Polling... 在电力系统MIS开发建设中,远动实时信息经加工后进入管理信息网是一项基本功能要求。实时信息进入管理信息网,首先要解决如何从远动系统接收数据的问题。本文结合“广西西津电厂远动实时信息网络监视系统”的开发,介绍如何实现Polling规约远动实时信息的接收问题。 展开更多
关键词 电力系统 polling规约 数据接收 实时数据
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基于POLLING方式的分布式监控系统
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作者 贾智平 《计算机工程与应用》 CSCD 北大核心 1997年第3期61-63,69,共4页
本文介绍了一个用于自来水生产行业的分布式微机监控系统,给出了由8098单片机组成的有线及无线混合通信网络方案。并结合8098的特点,推出了一个抗干扰能力强、码效率高。
关键词 自来水 监控系统 polling 分布式
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A DISCRETE TIME TWO-LEVEL MIXED SERVICE PARALLEL POLLING MODEL 被引量:6
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作者 GuanZheng ZhaoDongfeng ZhaoYifan 《Journal of Electronics(China)》 2012年第1期103-110,共8页
We present a discrete time single-server two-level mixed service polling systems with two queue types, one center queue and N normal queues. Two-level means the center queue will be successive served after each normal... We present a discrete time single-server two-level mixed service polling systems with two queue types, one center queue and N normal queues. Two-level means the center queue will be successive served after each normal queue. In the first level, server visits between the center queue and the normal queue. In the second level, normal queues are polled by a cyclic order. Mixed service means the service discipline are exhaustive for center queue, and parallel 1-limited for normal queues. We propose an imbedded Markov chain framework to drive the closed-form expressions for the mean cycle time, mean queue length, and mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical the new system efficiently differentiates priorities. 展开更多
关键词 polling model PRIORITY TWO-LEVEL Mixed-service Waiting time
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Dynamic Polling MAC Scheme Considering Emergency Access in WSNs Based on Priorities 被引量:3
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作者 Pei Qingqi Chen Chen Xie Weiguang 《China Communications》 SCIE CSCD 2012年第4期45-54,共10页
In Wireless Sensor Networks(WSNs),polling can obviously improve the throughput and decrease average access delay by allocating bandwidth efficiently and reasonably.In this paper,a Dynamic Polling Media Access Control ... In Wireless Sensor Networks(WSNs),polling can obviously improve the throughput and decrease average access delay by allocating bandwidth efficiently and reasonably.In this paper,a Dynamic Polling Media Access Control (DPMAC) scheme designed according to WSNs' features is proposed.DPMAC is a priority based access control protocol with the characteristics that its polling table is dynamically refreshed depending on whether the sensor node is active and that the bandwidth is dynamically allocated according to the traffic types.The access priorities are determined by the emergency levels of events and the scheduler proposed in our MAC is preemptive based on the deadline of the events.Simulation results show that DPMAC can efficiently utilize bandwidth and decrease average access delay and response time for emergency events with different access priorities in WSNs. 展开更多
关键词 WSNS polling THROUGHPUT MAC
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Achieving Energy Efficiency in Wireless Sensor Networks Using Dynamic Channel Polling and Packet Concatenation 被引量:1
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作者 Shama Siddiqui Anwar Ahmed Khan Sayeed Ghani 《China Communications》 SCIE CSCD 2021年第8期249-270,共22页
There has been a significant interest of researchers to combine different schemes focused on optimizing energy performance while developing aMAC protocol for Wireless Sensor Networks(WSNs).In this paper,we propose to ... There has been a significant interest of researchers to combine different schemes focused on optimizing energy performance while developing aMAC protocol for Wireless Sensor Networks(WSNs).In this paper,we propose to integrate two cross-layer schemes:dynamic channel polling and packet concatenation using a recent asynchronous MAC protocol“Adaptive&Dynamic Polling MAC”(ADPMAC).ADP-MAC dynamically selects the polling interval distribution based on characterization of incoming traffic patterns using Coefficient of variation(CV).Packet Concatenation(PC)refers to combining the individually generated data packets into a single super packet and sending it at the polling instant.Also,the Block Acknowledgement(BA)scheme has been developed for ADP-MAC to work in conjunction with the packet concatenation.The proposed schemes have been implemented in Tiny-OS for Mica2 platform and Avrora emulator has been used for conducting experiments.Simulation results have revealed that the performance both in terms of energy&packet loss improves when ADP-MAC is used in conjunction with the additional features of PC&BA.Furthermore,the proposed scheme has been compared with a stateof-art packet concatenation primitive PiP(Packet-in-Packet).It has been observed that ADP-MAC supersedes the performance of PiP in terms of PDR(Packet Delivery Ratio)due to better management of synchronization between source and sink. 展开更多
关键词 energy efficiency CONCATENATION DYNAMIC polling
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A PRIORITY-BASED POLLING SCHEDULING ALGORITHM FOR ARBITRATION POLICY IN NETWORK ON CHIP 被引量:1
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作者 Bao Liyong Zhao Dongfeng Zhao Yifan 《Journal of Electronics(China)》 2012年第1期120-127,共8页
A solution is imperatively expected to meet the efficient contention resolution schemes for managing simultaneous access requests to the communication resources on the Network on Chip (NoC). Based on the ideas of conf... A solution is imperatively expected to meet the efficient contention resolution schemes for managing simultaneous access requests to the communication resources on the Network on Chip (NoC). Based on the ideas of conflict-free transmission, priority-based service, and dynamic self-adaptation to loading, this paper presents a novel scheduling algorithm for Medium Access Control (MAC) in NoC with the researches of the communication structure features of 2D mesh. The algorithm gives priority to guarantee the Quality of Service (QoS) for local input port as well as dynamic adjustment of the performance of the other ports along with input load change. The theoretical model of this algorithm is established with Markov chain and probability generating function. Mathematical analysis is made on the mean queue length and the mean inquiry cyclic time of the system. Simulated experiments are conducted to test the accuracy of the model. It turns out that the findings from theoretical analysis correspond well with those from simulated experiments. Further more, the analytical findings of the system performance demonstrate that the algorithm enables effectively strengthen the fairness and stability of data transmissions in NoC. 展开更多
关键词 Network on Chip(NoC) Arbitration policies Priority-based polling Dynamic load adaptation
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POLLING远动规约中CRC校验码的算法及程序实现
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作者 骆昌军 盛翊智 付海帆 《电脑与信息技术》 1994年第3期2-4,共3页
电力系统中广泛应用的POLLING运动规约,使用了国际标准化组织ISO制定的HDLC标准CRC校验码.本文具体介绍了CRC校验码的计算方法,并从软件工程的角度详细介绍了算法及其程序设计,此程序已成功地应用于N4F与本地功能计算机的数据通讯.
关键词 电力系统 polling规约 CRC校验码 算法 程序设计
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Design and Analysis of Com munication Network for Distributed SCADA System
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作者 王倩 钱清泉 《Journal of Modern Transportation》 1999年第2期154-162,共9页
This paper presents the design of hierarchical communication network for traction power supply supervisory control and data acquisition (SCADA) system. Some key points, such as data transmission synchronization, datab... This paper presents the design of hierarchical communication network for traction power supply supervisory control and data acquisition (SCADA) system. Some key points, such as data transmission synchronization, database distribution, data transformation, and the network communication optimization at the supervisory level of the communication network are discussed. At the control level, based on the specificity of communication lines for electrified railway, a structure of two layer ring telecommunication network and the efficient bi directional polling scheme in software design are utilized. Then, an analysis for the scheme under normal and disturbance conditions is given. By means of the scheme, software switching over at a fault point of a channel is realized automatically. 展开更多
关键词 DISTRIBUTION SCADA communication network bi directional polling
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Improved Radio Network Dimensioning for Real-Time Polling Service on IEEE 802.16 Wireless Networks with QoS Consideration
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作者 Thiaw Seng Ng Teong Chee Chuah Yi Fei Tan 《International Journal of Communications, Network and System Sciences》 2012年第3期192-205,共14页
Recently, applications of real-time polling service (rtPS) in IEEE 802.16 wireless networks have gained considerable popularity. These applications generate large amounts of real time traffic in the network and thus m... Recently, applications of real-time polling service (rtPS) in IEEE 802.16 wireless networks have gained considerable popularity. These applications generate large amounts of real time traffic in the network and thus maintaining the quality of service (QoS) such as packet delay requirement in rtPS dominant networks is critical. Existing dimensioning methodology does not consider QoS parameters of rtPS in network dimensioning. Moreover, exhaustive and time-consuming simulations are required to evaluate the performance and QoS of rtPS. To overcome this problem, we propose an improved radio network dimensioning framework which considers QoS parameters of rtPS in network dimensioning. In this framework, an analytical model is developed to evaluate the capacity and performance of rtPS in IEEE 802.16 wireless networks. The proposed framework provides a fast and accurate means of finding the trade-off between system load and packet delay, thus providing network operators with an analytical tool that jointly considers coverage, capacity and QoS requirements for obtaining the minimum number of sites required. The accuracy of the proposed model is validated through simulations. 展开更多
关键词 IEEE802.16 DIMENSIONING Analytical Model Real Time polling SERVICE QOS
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An Opinion Poll for the Establishment of a Bioethanol Plant Utilizing Local Resources and a Fuzzy Inference System
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作者 Michael N. Tsatiris 《Journal of Environmental Science and Engineering(B)》 2015年第4期190-202,共13页
The cultivation of sweet sorghum (sorghum bicolor) is still one of the new promising energy crops for bioethanol production nowadays. An opinion poll for the establishment of a bioethanol plant utilizing local resou... The cultivation of sweet sorghum (sorghum bicolor) is still one of the new promising energy crops for bioethanol production nowadays. An opinion poll for the establishment of a bioethanol plant utilizing local resources such as the cultivation of sweet sorghum and the zeolite deposits was held. Data were collected by heads of selected households of the Municipality of Trigono (Evros, Greece). The simple random sampling was applied and a face-to-face interviewing and filling in of the forms of a questionnaire was conducted. It was estimated that some 44,778-55,971 acres of land should be cultivated with sweet sorghum for a satisfactory production of bioethanol in a bioethanol plant in the order of 120,000-150,000 tons/year. Furthermore, in this paper an optimum solution was estimated by using of the Fuzzy Logic Toolbox of Matlab (Intelligent system) which is formulated as follows "the bioethanol plant absorbing the sweet sorghum's production of a cultivating area of 46,600 acres and operating 12 hours/day would produce 125,000 tons of bioethanol annually". Such a vast area of land would offer occupation to a significant number of young farmers for the cultivation of sweet sorghum. 展开更多
关键词 Opinion poll sweet sorghum CLINOPTILOLITE bioethanol's plant fuzzy logic.
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Adaptive Polling Rate for SNMP for Detecting Elusive DDOS
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作者 Yichiet Aun Yen-Min Jasmina Khaw +1 位作者 Ming-Lee Gan Vasaki Ponnusamy 《Journal of Cyber Security》 2022年第1期17-28,共12页
Resilient network infrastructure is pivotal for business entities that are growing reliance on the Internet.Distributed Denial-of-Service(DDOS)is a common network threat that collectively overwhelms and exhausts netwo... Resilient network infrastructure is pivotal for business entities that are growing reliance on the Internet.Distributed Denial-of-Service(DDOS)is a common network threat that collectively overwhelms and exhausts network resources using coordinated botnets to interrupt access to network services,devices,and resources.IDS is typically deployed to detect DDOS based on Snort rules.Although being fairly accurate,IDS operates on a computeintensive packet inspection technique and lacks rapidDDOSdetection.Meanwhile,SNMP is a comparably lightweight countermeasure for fast detection.However,this SNMP trigger is often circumvented if the DDOS burst rate is coordinated to flood the network smaller than theSNMPpolling rate.Besides,SNMP does not scale well if the poll rate is set extremely fine for improved detection accuracy.In this paper,a lightweight 3D SNMP scaling method is proposed to optimize the SNMP poll rate forDDOSmitigation automatically.The 3D-SNMP uses horizontal scaling to dynamically adjust the optimal poll rate through random packet inspection that is selective.Suppose a sign of DDOS is detected,3D-SNMP scales down the poll rate for finer detection.As DDOS subsides,3D-SNMP scales the poll rate up for faster DDOS detection.The equilibrium between scalability and accuracy is determined on the fly depending on the types of DDOS variants.3D-SNMP also adds a vertical scaling to detect non-salient DDOS that falls below the detection threshold.The experimental results showed that 3D-SNMP achieved DDOS detection of 92%while remaining scalable to different DDOS variants and volumes. 展开更多
关键词 SNMP DDOS poll rate network security threat detection
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POLLING方式RTU装置接入SCADA系统的技术研究
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作者 董长玲 李杰 《吉林电力》 1994年第5期1-4,13,共5页
论述了POLLING方式RTU接入国内开发的SCADA系统的技术原理、方法及结构配置、功能。并通过省调SCADA系统接收μ4F、N4F型RTU的实例,较详细地介绍了POLLING方式RTU严格按部颁通讯规约接入SCADA系统的程序设计流程、主要程序模块及各程序... 论述了POLLING方式RTU接入国内开发的SCADA系统的技术原理、方法及结构配置、功能。并通过省调SCADA系统接收μ4F、N4F型RTU的实例,较详细地介绍了POLLING方式RTU严格按部颁通讯规约接入SCADA系统的程序设计流程、主要程序模块及各程序包的功能和使用说明。 展开更多
关键词 调度自动化 SCADA polling RTU 程序设计
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分布对象中间件中的异步机制代码生成研究 被引量:4
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作者 张志伟 吴泉源 《计算机工程与应用》 CSCD 北大核心 2003年第6期41-43,共3页
随着分布对象中间件CORBA应用领域的扩展,许多应用需要在CORBA中提供异步机制。传统的CORBA不提供异步激活机制。笔者在对象中间件CORBA领域率先实现了异步Polling机制。论文研究与在分布对象中间件CORBA中实现异步Polling机制相关的代... 随着分布对象中间件CORBA应用领域的扩展,许多应用需要在CORBA中提供异步机制。传统的CORBA不提供异步激活机制。笔者在对象中间件CORBA领域率先实现了异步Polling机制。论文研究与在分布对象中间件CORBA中实现异步Polling机制相关的代码生成机制。提出了基于修改抽象语法树的异步代码生成算法,实现结果表明该算法可以满足模型的要求。 展开更多
关键词 分布对象中间件 异步机制 代码生成 CORBA polling模型 网络计算 计算机网络
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Polι在膀胱尿路上皮癌细胞株及肿瘤组织中mRNA的表达 被引量:2
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作者 赵谦 曾益军 +7 位作者 杨劲 金锡御 陈志文 宋波 位全芳 季惠翔 李劲 周虎传 《第三军医大学学报》 CAS CSCD 北大核心 2008年第14期1305-1307,共3页
目的检测DNA聚合酶ι(Polymerase iota,Polι)在尿路上皮癌细胞株及肿瘤组织的表达,探讨Polι在尿路上皮癌组织表达的意义。方法培养尿路上皮癌细胞株BIU87、T24,反转录聚合酶链式反应(Reverse transciptase-polymer-ase chain reaction... 目的检测DNA聚合酶ι(Polymerase iota,Polι)在尿路上皮癌细胞株及肿瘤组织的表达,探讨Polι在尿路上皮癌组织表达的意义。方法培养尿路上皮癌细胞株BIU87、T24,反转录聚合酶链式反应(Reverse transciptase-polymer-ase chain reaction,RT-PCR)检测Polι在尿路上皮癌细胞株的表达;收集人膀胱黏膜正常组织及临床膀胱尿路上皮癌、肾盂尿路上皮癌组织标本,检测组织标本中Polι的表达。结果Polι在尿路上皮癌细胞株有丰富表达,显著高于膀胱正常黏膜组织;Polι在膀胱尿路上皮癌及肾盂癌组织的表达显著高于膀胱正常黏膜组织的表达(P<0.01),并与尿路上皮癌的分级有关。结论Polι在尿路上皮癌组织的高表达可能与尿路上皮癌的发生、发展有关。 展开更多
关键词 DNA聚合酶 POLL 尿路上皮癌
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Pell方程解的几个公式 被引量:2
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作者 吴小明 杨观赐 赵伟科 《湖南理工学院学报(自然科学版)》 CAS 2006年第2期10-13,共4页
在扼要介绍连分数的基础上,通过对Pell方程的解的分析,绕过传统的研究方法与研究角度,利用计算机并引入连分数算法,在大量真实可靠数据的基础上,给出并证明了在Pell方程中当y为某一确定的值时,Pell方程的解的几个公式。
关键词 Poll方程 连分数 公式
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USB嵌入式系统上层应用软件的设计与实现 被引量:2
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作者 李武 《微电子学与计算机》 CSCD 北大核心 2006年第6期178-180,共3页
系统在USB协议基础上,以DVD解决方案为依托,实现嵌入式USB主机系统在家庭娱乐消费产品中的应用软件设计与实现。文章介绍了USB协议的相关内容,系统结构的设计,系统部分上层软件的设计。
关键词 USB 体系结构 系统流程 polling 软件的设计
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