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21.
22.
The problem of channel sharing by rate adaptive streams belonging to various classes is considered. Rate adaptation provides
the opportunity for accepting more connections by adapting the bandwidth of connections that are already in the system. However,
bandwidth adaptation must be employed in a careful manner in order to ensure that (a) bandwidth is allocated to various classes
in a fair manner (system perspective) and (b) bandwidth adaptation does not affect adversely the perceived user quality of
the connection (user quality). The system perspective aspect has been studied earlier. This paper focuses on the equally important
user perspective. It is proposed to quantify user Quality of Service (QoS) through measures capturing short and long-term
bandwidth fluctuations that can be implemented with the mechanisms of traffic regulators, widely used in networking for the
purpose of controlling the traffic entering or exiting a network node. Furthermore, it is indicated how to integrate the user
perspective metrics with the optimal algorithms for system performance metrics developed earlier by the authors. Simulation
results illustrate the effectiveness of the proposed framework.
Nikos G. Argiriou received the Diploma degree in Electrical Engineering from the Department of Electrical Engineering, Telecommunication Division, Aristotle University of Thessaloniki, Greece, in 1996. He worked as a researcher, on secure medical image transmission over networks, at the Image Processing Lab at the same university during 1996–1997. During 1998–2000 he was a researcher for the European Project Esprit Catserver concerning the use of advanced Quality of Service techniques in CATV networks. He received his Ph.D. degree at Aristotle University of Thessaloniki in 2007. His current research interests are in the development and implementation of QoS techniques for wired and wireless networks. Leonidas Georgiadis received the Diploma degree in Electrical Engineering from Aristotle University, Thessaloniki, Greece, in 1979, and his M.S. and Ph.D degrees both in Electrical Engineering from the University of Connecticut, in 1981 and 1986, respectively. From 1986 to 1987 he was Research Assistant Professor at the University of Virginia, Charlottesville. In 1987 he joined IBM T. J. Watson Research Center, Yorktown Heights as a Research Staff Member. Since October 1995, he has been with the Telecommunications Department of Aristotle University, Thessaloniki, Greece. His interests are in the area of wireless networks, high speed networks, routing, scheduling, congestion control, modeling and performance analysis. 相似文献
Leonidas GeorgiadisEmail: |
Nikos G. Argiriou received the Diploma degree in Electrical Engineering from the Department of Electrical Engineering, Telecommunication Division, Aristotle University of Thessaloniki, Greece, in 1996. He worked as a researcher, on secure medical image transmission over networks, at the Image Processing Lab at the same university during 1996–1997. During 1998–2000 he was a researcher for the European Project Esprit Catserver concerning the use of advanced Quality of Service techniques in CATV networks. He received his Ph.D. degree at Aristotle University of Thessaloniki in 2007. His current research interests are in the development and implementation of QoS techniques for wired and wireless networks. Leonidas Georgiadis received the Diploma degree in Electrical Engineering from Aristotle University, Thessaloniki, Greece, in 1979, and his M.S. and Ph.D degrees both in Electrical Engineering from the University of Connecticut, in 1981 and 1986, respectively. From 1986 to 1987 he was Research Assistant Professor at the University of Virginia, Charlottesville. In 1987 he joined IBM T. J. Watson Research Center, Yorktown Heights as a Research Staff Member. Since October 1995, he has been with the Telecommunications Department of Aristotle University, Thessaloniki, Greece. His interests are in the area of wireless networks, high speed networks, routing, scheduling, congestion control, modeling and performance analysis. 相似文献
23.
Bruno Juliá-Díaz Joseph M. Burdis Frank Tabakin 《Computer Physics Communications》2006,174(11):914-934
This Mathematica 5.2 package1 is a simulation of a Quantum Computer. The program provides a modular, instructive approach for generating the basic elements that make up a quantum circuit. The main emphasis is on using the density matrix, although an approach using state vectors is also implemented in the package. The package commands are defined in Qdensity.m which contains the tools needed in quantum circuits, e.g., multiqubit kets, projectors, gates, etc. Selected examples of the basic commands are presented here and a tutorial notebook, Tutorial.nb is provided with the package (available on our website) that serves as a full guide to the package. Finally, application is made to a variety of relevant cases, including Teleportation, Quantum Fourier transform, Grover's search and Shor's algorithm, in separate notebooks: QFT.nb, Teleportation.nb, Grover.nb and Shor.nb where each algorithm is explained in detail. Finally, two examples of the construction and manipulation of cluster states, which are part of “one way computing” ideas, are included as an additional tool in the notebook Cluster.nb. A Mathematica palette containing most commands in QDENSITY is also included: QDENSpalette.nb.
Program summary
Title of program: QDENSITYCatalogue identifier: ADXH_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXH_v1_0Program available from: CPC Program Library, Queen's University of Belfast, N. IrelandOperating systems: Any which supports Mathematica; tested under Microsoft Windows XP, Macintosh OS X, and Linux FC4Programming language used: Mathematica 5.2No. of bytes in distributed program, including test data, etc.: 180 581No. of lines in distributed program, including test data, etc.: 19 382Distribution format: tar.gzMethod of solution: A Mathematica package is provided which contains commands to create and analyze quantum circuits. Several Mathematica notebooks containing relevant examples: Teleportation, Shor's Algorithm and Grover's search are explained in detail. A tutorial, Tutorial.nb is also enclosed. 相似文献24.
The paper contains a review of some results concerning probability theory on MV algebras (laws of large numbers, central
limit theorem, martingale convergence theorem). Also some algebraic and methodical aspects are discussed. 相似文献
25.
The parallelism attained by the use of Field Programmable Gate Arrays (FPGAs) has shown remarkable potential for accelerating control systems applications. This comes at a time when well established methods based on inherited serial Central Processor Units (CPUs) cannot guarantee solutions for the increasing execution speed demands. However, the transition from serial to parallel architectures represents a tremendous challenge due to overwhelming numbers of unexplored options and conflicting factors. The work presented achieves a parallelisation characterisation for generic MIMO systems using stand-alone FPGA implementations. The main contribution is that a very fine subset of possible serial/parallel implementations is obtained. This is used to achieve a flexible trade-off between cost and performance. Automatic optimisation of latency, occupied FPGA area and execution speed is attained and justified in respect to most of the feasible scenarios. 相似文献
26.
为了研究氢化芳烃的微观结构,进一步认识和理解氢化芳烃在催化裂化过程中的反应特性。以四氢萘为模型化合物,利用基于密度泛函理论的量子化学从头计算方法,对四氢萘的几何结构和电子结构进行了系统研究,得到了四氢萘不同位置C-H键和C-C键的键长、键级、键能以及电子云密度、前线轨道分布等微观结构信息。发现四氢萘结构具有轴对称特性,苯环上的C-C键和C-H键要远比环烷环的C-C键和C-H键稳定。由于受苯环的影响,会使得其环烷环上不同位置的C-C键的键长、键级和键能均具有明显差异,也导致环烷环上不同位置C-H键的键长、键级和键能有较明显的差异,具体表现为:对C-C键而言,与苯环相连的C-C键的键长较短,键级较高,键能也明显较高,而苯环β位C-C键的键能则明显较低;对C-H键而言,与苯环β位环烷碳原子上的C-H键相比,苯环α位环烷碳原子上的C-H键的键能明显较低。电子云分布计算结果能够较好地给出的这些C-C键和C-H键结构特征差异的原因。前线轨道计算结果表明,在催化裂化过程中,苯环α位环烷碳原子上的C-H键和β位C-C键较易受到催化剂酸性中心的进攻,是酸催化反应的位点。这些计算结果对于认识与理解氢化芳烃的反应特性具有一定的基础性理论意义。 相似文献
27.
It is shown that a stochastic matrix operator (quantum measurement matrix) may be considered in some cases as a density matrix.
Results of measurements in the form of figure numbers, interconnected with a matrix of quantum measurements, are similar to
quantum observable quantities determined in quantum statistical theory.
__________
Translated from Izmeritel’naya Tekhnika, No. 12, pp. 3–8, December, 2006. 相似文献
28.
用于MIS的实时数据共享软件平台的设计与实现 总被引:1,自引:0,他引:1
电网企业的各种信息,相互间具有相当紧密的关联关系,这些信息关联的核心就是电网实时数据。将电网实时数据引入到管理信息系统(MIS)中,使管理信息系统能够有效的分析利用实时数据对于促进电力系统的信息化发展具有重要意义。本文详细的阐述了用于管理信息系统(MIS)的电网实时数据共享软件平台的系统结构、工作原理以及设计与实现,提出了解决电网企业生产网和管理网信息共享以及MIS各个子系统同时共享调度实时数据的技术手段,并介绍了系统在电网信息管理系统中的具体应用。 相似文献
29.
30.
对工程项目管理系统的认识 总被引:1,自引:0,他引:1
工程项目管理系统是企业信息系统中关键的子系统。用于指导和协调其它子系统之间业务传递和数据共享。针对工程项目管理存在的信息沟通困难、数据易变化、书面文档多的难点,在建立工程项目管理系统时。可通过计算机网络系统、信息沟通系统、电子文档管理系统、项目数据管理系统等来实现对工程项目的管理。 相似文献