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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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优化的EPON前摄Polling机制 被引量:1
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作者 张晋豫 黄成富 +1 位作者 王众 梁满贵 《北京邮电大学学报》 EI CAS CSCD 北大核心 2008年第5期61-64,共4页
利用由多个关键报告生成的插值多项式预测方程来预测未来几个周期的业务量,通过1个消息(grant)对多个周期的授权,节省了带宽和减少了数据包的时延,建立了知识支撑系统(KSS)系统,通过偏导(DC)寻优法来优化关键周期和预测周期的个数,通过... 利用由多个关键报告生成的插值多项式预测方程来预测未来几个周期的业务量,通过1个消息(grant)对多个周期的授权,节省了带宽和减少了数据包的时延,建立了知识支撑系统(KSS)系统,通过偏导(DC)寻优法来优化关键周期和预测周期的个数,通过神经网络来优化非线形预测方程的调节因子.仿真结果很好地验证了它的效果. 展开更多
关键词 以太无源光网络 神经网络 轮巡 优化
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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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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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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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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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A Priority-aware Frequency Domain Polling MAC Protocol for OFDMA-based Networks in Cyber-physical Systems 被引量:1
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作者 Meng Zheng Junru Lin +1 位作者 Wei Liang Haibin Yu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI 2015年第4期412-421,共10页
Wireless networking in cyber-physical systems (CPSs) is characteristically different from traditional wireless systems due to the harsh radio frequency environment and applications that impose high real-time and relia... Wireless networking in cyber-physical systems (CPSs) is characteristically different from traditional wireless systems due to the harsh radio frequency environment and applications that impose high real-time and reliability constraints. One of the fundamental considerations for enabling CPS networks is the medium access control protocol. To this end, this paper proposes a novel priority-aware frequency domain polling medium access control (MAC) protocol, which takes advantage of an orthogonal frequency-division multiple access (OFDMA) physical layer to achieve instantaneous priority-aware polling. Based on the polling result, the proposed work then optimizes the resource allocation of the OFDMA network to further improve the data reliability. Due to the non-polynomial-complete nature of the OFDMA resource allocation, we propose two heuristic rules, based on which an efficient solution algorithm to the OFDMA resource allocation problem is designed. Simulation results show that the reliability performance of CPS networks is significantly improved because of this work. © 2014 Chinese Association of Automation. 展开更多
关键词 Access control Embedded systems Frequency domain analysis Medium access control Network layers Orthogonal frequency division multiplexing POLYNOMIALS Real time systems Reliability Resource allocation Wireless networks
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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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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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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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离散时间的完全服务并行优化轮询排队系统特性分析
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作者 保利勇 丁新昱 +2 位作者 丁洪伟 官铮 葛俊阳 《电子学报》 EI CAS CSCD 北大核心 2024年第3期838-848,共11页
轮询是一种依次有序服务的系统资源动态调度机制.针对服务器在站点间查询、服务和转移过程中的流水线作业方式导致了系统整体服务效率较低的问题,本文提出了完全服务的并行优化轮询系统.首先,构建了系统的单服务器多队列排队模型和相应... 轮询是一种依次有序服务的系统资源动态调度机制.针对服务器在站点间查询、服务和转移过程中的流水线作业方式导致了系统整体服务效率较低的问题,本文提出了完全服务的并行优化轮询系统.首先,构建了系统的单服务器多队列排队模型和相应的系统状态方程,并精确解析出系统特性参数的完整数学解析表达式.此外,还提出了一种系统状态稳定性的判定方法,对不同负载状态下的系统稳定性进行了定量分析.计算机仿真的统计分析结果与理论计算值相一致.最后,系统性能分析表明,在保持周期性、无冲突服务的基础上,系统的队长、时延特性和稳定状态下负载能力均得到了较大的提高. 展开更多
关键词 轮询 并行优化调度 完全服务 队长特性 时延特性 系统稳定性
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基于排队论的一种高吞吐量信道分配协议设计
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作者 陶志勇 张鑫诺 +1 位作者 王诗 高党召 《计算机应用研究》 CSCD 北大核心 2024年第9期2815-2822,共8页
针对复杂多变的认知无线电系统中难以为次用户高效分配信道的问题,提出了一种高吞吐量信道分配协议——TKMA协议。该协议根据主用户(PU)活动、次用户(SU)实时业务需求、信道条件等信息构建用户信道的效用矩阵,在保障PU通信质量的前提下... 针对复杂多变的认知无线电系统中难以为次用户高效分配信道的问题,提出了一种高吞吐量信道分配协议——TKMA协议。该协议根据主用户(PU)活动、次用户(SU)实时业务需求、信道条件等信息构建用户信道的效用矩阵,在保障PU通信质量的前提下以SU系统总效用值最大化为目标进行信道分配,并利用改进Kuhn-Munkras算法结合轮询调度进行求解。为了评估该协议性能,建立了通用的多用户多信道认知无线电系统模型,利用排队理论描述数据包传输过程,并通过马尔可夫稳态求解推导出SU的性能指标。实验结果表明,与以往提出的化简方法和传统的公平随机分配协议相比,使用TKMA协议在SU系统总的吞吐量、平均时延、平均队长、拒绝率等指标上都取得了更优的结果,证明了所提协议和系统模型的有效性。 展开更多
关键词 排队分析 信道分配协议 认知无线电网络模型 Kuhn-Munkras算法 轮询调度
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5G系统中信道上行调度应用研究
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作者 徐啸涛 《电脑与电信》 2024年第1期29-31,61,共4页
信道上行调度器对调度值的相对信号强度参数进行科学计算,并规范处理两个符号指定的程式区域,从不同角度指定PUSCH区域的子部分。PRB分配的正则化调度区域(上行调度程序从PRB分配开始的区域)将根据区域中测量的干扰和噪声功率,分配给蜂... 信道上行调度器对调度值的相对信号强度参数进行科学计算,并规范处理两个符号指定的程式区域,从不同角度指定PUSCH区域的子部分。PRB分配的正则化调度区域(上行调度程序从PRB分配开始的区域)将根据区域中测量的干扰和噪声功率,分配给蜂窝小区,最后给出相应的仿真数据,验证信道上行调度的操作情况。 展开更多
关键词 上行调度器 干扰 轮询调度 捕获
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循环轮询系统任务阻塞应对策略研究
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作者 杜隆胤 《工业控制计算机》 2024年第9期103-104,共2页
针对循环轮询系统任务中的延时阻塞和事件阻塞导致的系统死锁、实时性不能保证和用户体验差问题,根据任务周期性和阻塞类型对任务进行分类拆分。拆分后的任务周期性和执行条件与原任务及阻塞特性有关。
关键词 循环轮训 延时阻塞 事件阻塞 任务拆分
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杜泊、无角陶赛特、萨福克羊与湖羊杂交F_(1)代羔羊育肥性能研究
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作者 郭志明 《畜牧兽医杂志》 2024年第3期29-31,共3页
为进一步研究不同肉羊品种与湖羊杂交F_(1)代羔羊育肥效果,本试验选择国外优良的肉羊品种杜泊羊、无角陶赛特羊和萨福克羊作父本,国内优良地方品种湖羊作母本开展杂交试验研究,所获得的杂交F_(1)代羔羊在全舍饲条件下进行育肥。测定杂交... 为进一步研究不同肉羊品种与湖羊杂交F_(1)代羔羊育肥效果,本试验选择国外优良的肉羊品种杜泊羊、无角陶赛特羊和萨福克羊作父本,国内优良地方品种湖羊作母本开展杂交试验研究,所获得的杂交F_(1)代羔羊在全舍饲条件下进行育肥。测定杂交F_(1)代羔羊初生重、不同月龄体重和平均日增重等生长性能。结果表明:试验A组(杜泊公羊与湖羊母羊杂交F_(1)羔羊)、试验B组(无角陶赛特公羊与湖羊母羊杂交F_(1)羔羊)、试验C组(萨福克公羊与湖羊母羊杂交F_(1)羔羊)6月龄平均重分别为44.76±3.62 g、 43.65±4.18 g、43.28±3.34 g,均极显著高于对照组D 6月龄平均重36.32±3.86 g,差异极显著(P<0.01)。试验A组、B组、C组与对照组D相比较,试验A组、B组、C组每只羊的利润较对照组分别多收入80.02元、69.74、42.74元,差异极显著(P<0.01),其中试验A组的生长性能和利润均优于试验B组和C组,差异显著(P<0.05)。 展开更多
关键词 杜泊羊 无角陶赛特羊 萨福克羊 湖羊 育肥性能
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