bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active Plasma Boundary Sheath with Electron Emission
Authors: Hantzsche E. 
Published: July 2007

AbstractThe influence of electron emission on the properties of the space charge sheath between plasma and wall is investigated theoretically using models of the stationary sheath. Especially, the following effects have been considered:Essential parameters of the sheath (e.g. potential drop, power flux density), of the wall surface (temperature, field strength, emission yield, Joule heat generation) and of the adjacent plasma layer (emission‐caused change of the electron temperature) have been calculated under self‐consistent conditions.From the obtained results several ways are discusséd indicating the development towards sheath instability and ending in the generation of plasma‐induced arc spots.
Polarizations of Magnetohydrodynamic Waves in a Cold Multi‐Species Plasma
Authors: Suchy K. 
Published: July 2007

AbstractStarting with the expression for the permittivity tensor for a loss‐free magnetoplasma the low‐frequency limits of its eigenvalues are calculated. They are used for the dispersion relations and polarization ratios of the shear Alfvén mode and the fast magnetosonic mode.
Intense Heavy Ion Beams as a Tool to Produce and Analyze Dense Plasmas
Authors: Neuner U. , Bock R. , Funk U. N. , Hoffmann D. H. H. , Stetter M. , Stöwe S. , Tauschwitz A. , Udrea S. 
Published: July 2007

AbstractThe synchrotron SIS at GSI presently offers the possibility to heat samples of matter at solid state density to temperatures between 0.2 and 1 eV within times shorter than the desintegration time of these samples. Hot matter below solid state density can be investigated using the expanding sample, whereas densities above solid state density are produced by shock wave compression in compound targets.Measurements of sample expansion and pressure as well as corresponding simulations are presented. Future experimental schemes are discussed including the use of the ion beam as a diagnostic tool for dense plasma, relating its energy loss to the sample density.
Non‐Markovian Kinetics for Nonuniform Plasmas
Authors: Wallenborn J. 
Published: July 2007

AbstractThe nonlinear Balescu‐Lenard kinetic equation has been generalised to weakly nonideal spatially nonuniform polarisable plasmas. This is done by including nonlocality in space and time in the collision term. The local laws of conservation for particle, momentum and total energy densities follow. Some outstanding problems are discussed.
Quantum Molecular Dynamics Simulations of Dense Matter
Authors: Bickham S. R. , Collins L. A. , Kress J. D. 
Published: July 2007

AbstractWe have developed a quantum molecular dynamics simulation method for treating dense plasmas and a variety of other systems. The approach treats the electrons fully quantum mechanically and the nuclei classically. Applications include H plasmas, alkali metal fluids, rare gas compression, mixtures, impurities in plasmas, and shock‐compressed hydrocarbons.
Calculation of the Radiative Opacity of a Hot Dense Plasma
Authors: Orlov N. 
Published: July 2007

AbstractResults are presented for a theoretical model, known as the ion model (IM), recently elaborated to calculate the radiative opacity of a hot dense plasma. The model is based on the self‐consistent field method for subsystems obeying Gibbs statistics. The model is applied to compound chemical compositions. The problem of optimal selection of compound compositions is discussed both for laser and heavy ions targets designs.
Density Expansions of the Reduced Distribution Functions and the Excess Free Energy for Plasma with Coulomb and Short‐Range Interactions
Authors: Kahlbaum T. 
Published: July 2007

AbstractThe equilibrium properties of a multi‐component plasma of charged particles that interact through the Coulomb potential and general short‐range potentials are investigated at low density within the framework of classical statistics. In particular, this article presents density expansions of (1) the reduced distribution functions for two and more particles up to second order as obtained from the screened Bogoliubov‐Born‐Green‐Kirkwood‐Yvon hierarchy and (2) the interaction contribution to the Helmholtz free energy including a new closed representation of the fourth cluster integral derived with the help of a usual charging procedure.
K‐Entropies of Electrons and Ions in Nonideal Plasmas
Authors: Morozov I. V. , Norman G. E. , Valuev A. A. 
Published: July 2007

AbstractThe Krylov‐Kolmogorov entropy (K‐entropy) is calculated for electrons and ions in nonideal plasmas by the method of molecular dynamics. Two different time scales are established corresponding to the electron and ion K‐entropies.
On Island Formation in a Locally Perturbed Tokamak Equilibrium
Authors: Kaleck A. 
Published: July 2007

AbstractTo control the plasma transport at the edge of a tokamak the outer flux surfaces can be artificially destroyed by applying a resonant helical magnetic field, as it is demonstrated at Pulsator [1],[2], [3], Tore Supra [4],[5] and proposed for TEXTOR‐94 [6] in the concept of “ergodic divertors”.As a measure of the efficiency of the perturbation field e.g. the level of the field line diffusion coefficient DFL the width Δi of the magnetic islands and the related Chirikov parameter are of importance [7],[8],[9],[10].For the planned Dynamic Ergodic Divertor (DED) at TEXTOR‐94 where the perturbation coils are located at the high field side the standard expression for Δi using the Fourier components of the magnetic field perturbation [7] leads to results significantly different from field line tracing calculations [11].The standard expression is commonly used in terms of the perturbation magnetic field δB [5],[7],[8],[9],[12],[13]. But when replacing the Fourier components of the perturbation vector potential by those of the magnetic field finite aspect ratio effects have been neglected so far. For present tokamaks with ϵ = r/R ≃ 0.3 this can lead to an error in the field line diffusion of one to two orders of magnitude.In this paper it is shown that taking into account the finite aspect ratio at this point leads to correct results compared to the highly precise field line tracing calculations by the Gourdon code. The island width then is recognized to depend significantly on the poloidal position of the perturbation field. This is in contrast to the standard expression. Also the role of the choice of the magnetic coordinate system is considered.
Probe Method for Measuring the Mach Number and the Flow Vector in Edge Plasma
Authors: Amemiya H. , Tsushima A. , Fuchs G. 
Published: July 2007

AbstractA planar Mach probe to measure the Mach number and the flow vector with respect to the magnetic field in the edge plasma of e.g. a tokamak is being proposed. The probe is constructed as a double probe and the saturation ion current is measured as function of the angle of rotation of the probe surface normal with respect to the magnetic field. The saturation current as function of the angle is calculated by taking a drifted Maxwellian distribution for ions and an effective size of the probe depending on the angle. From the ratio of the saturation currents for plus and minus biases respectively and from the envelope of the saturation current with respect to the rotation angle, the Mach number and the flow vector can be determined.
Economic comparisons of alternative fiber‐based local access architectures using ATM components
Authors: Reed David P. 
Published: July 2007

AbstractThis paper presents some engineering and economic comparisons of several fiber‐based network architectures providing narrowband, and in some cases broadband, services in the subscriber loop. Specifically, comparisons are made between different bus and star configurations in the sub‐feeder plant using asynchronous transfer mode (ATM) network components. The study reports in detail an engineering cost model used to determine the installed first cost of several access architectures, including severalfiber‐to‐the‐curbapproaches which interface to the existing copper drop. The results show that these approaches can reduce the initial first cost of fiber installation, although other issues regarding network operations, maintenance, and evolution still need to be addressed.
Loop‐network configuration and single‐mode optical fiber cable technologies for subscriber network
Authors: Ashiya Fumihiro , Matsumoto Michito , Nagasawa Shinji , Tomita Shigeru , Uenoya Takuya 
Published: July 2007

AbstractThis paper will discuss optical fiber cable distribution networks for accomodating the immediate introduction of optical subscriber networks. The concepts of cable distribution system design, the maintenance systems and the cables and jointing technology for supporting these systems will be discussed. The results of experiments using related technology will also be discussed.
A reasonable solution to the broadband congestion control problem
Authors: Cooper C. Anthony , Park Kun I. 
Published: July 2007

AbstractThe control of congestion in asynchronous transfer mode (ATM)‐based networks is an important and complex subject that must be properly addressed in order to permit efficient use of network capacity while providing good quality of service to all network users. This congestion control problem is characterized here, and the performance‐related aspects of some key congestion control features are modelled. Congestion controls for a broadband network will include features for admission control, buffer and queue management, traffic enforcement and reactive control. This paper identifies the leading alternatives for each of these congestion control features, presents an approach for comparing these alternatives based on the relative efficiencies achievable with each, and suggests one reasonable set of congestion control features. Our approch for comparing congestion control alternatives is based on a suitable model for the congestion‐related functions of an ATM‐based network, togther with a characterization of the traffic loads imposed by various broadband services.
ATM traffic control for guaranteed performance
Authors: Kositpaiboon Rungroj , Woodruff Gillian , Richards Philip 
Published: July 2007

AbstractTraffic controls in an ATM network must be designed to satisfy the bandwidth and performance requirements of a wide range of services. The challenge is to design simple and effective controls while allowing a reasonable utilization of bandwidth which can be achieved with statistical multiplexing. Several high‐level design principles for these controls are emphasized, and their implications on traffic types suitable for statistical multiplexing are illustrated with analytical and simulation performance results. A simple and effective control scheme is proposed to handle multiple traffic classes.
A congestion measure for call admission and traffic engineering for multi‐layer multi‐rate traffic
Authors: Hui Joseph Y. 
Published: July 2007

AbstractWe consider traffic control for services with constant bit rate (CBR) or multi‐layer Poisson statistics. Through the use of the Chernoff bound for the probability of traffic overflow, a congestion measure s* can be conveniently used for traffic control methodologies such as call admission and traffic engineering. We investigate extensively the mathematical properties of this congestion measure, and provide intuitive economical interpretations for the purpose of traffic integration. Applied to dynamic non‐hierarchical routing (DNHR), we show why the marginal bandwidth cost is a good criterion for choosing least cost paths.
Considerations in ATM switching system traffic control
Authors: Murakami Koso , Takase Tadahiro , Hajikano Kazuo , Hattori Shimmi 
Published: July 2007

AbstractWe propose a traffic control scheme for asynchronous transfer mode (ATM) switching systems, clarifying requirements for traffic control derived from the ATM network characteristics and demonstrating basic control concepts. The proposed scheme accepts calls based on the available bandwidth and buffer use rate, making it possible to integrate the network without classification by service type.
ND:YAG light source and external modulator for a VSB‐AM video transmitter: A performance evaluation
Authors: Trisno Y. , Grubb D. 
Published: July 2007

AbstractA miniature Nd:YAG laser and an intensity modulator based VSB‐AM video signal transmitter are described. With a light source having RIN level below ‐170 dB/Hz, the system allows a relatively low modulation index to be used. For a 40 channel system using a standard MZ, a CTB = 60 dB corresponds to mi = 1 per cent. With a 75 mW Nd:YAG laser source, a system with a power budget of 5.5 dB and 50 dB CNR is realizable. Several promising techniques of modulator linearization are also given.
Optical amplifiers for video distribution
Authors: Huber D. R. , Glaab J. B. 
Published: July 2007

AbstractThe promise of a broadband fibre communications network has attracted the interest of CATV and Telco concerns. Various networks and topologies have been discussed. Cost is a drawback in some of the proposed networks, particularly those networks which require switching. This paper discusses a low cost broadcast tree and branch network which uses optical amplifiers to extend the network penetration. Recent work in the development of optical amplifiers suggests that the Erbium fibre amplifier may be compatible with VSB‐AM. The characteristics of such an amplifier will be discussed. This scenario allows an orderly transition from the present‐day AM backbone system to the tree and branch fibre architecture. Once the broadband fibre plant is in place new services can be implemented that exploit the broadband nature of fibre.
An experimental ATM switch for BISDN studies
Authors: Palmer Rob 
Published: July 2007

AbstractThis paper describes the architecture, functionality and performance of an experimental ATM switch being developed at the Telecom Australia Research Laboratories as part of its investigations into the broadband ISDN. The proposed switch architecture consists of parallel omega networks preceded by a Batcher bitonic sorting network. The switching fabric has no internal cell buffering. Cell buffering is provided only on the switch outputs for cells simultaneously contending for the same output port. The switch fabric and cell buffers include mechanisms for providing prioritized servicing of queued cells and prioritized discarding of cells based on priority fields contained within the cell header. Components of the switch are currently being implemented in 2 μm CMOS VLSI.
A connection control strategy for bursty sources in broadband packet networks
Authors: Jabbari Bijan 
Published: July 2007

AbstractThis paper proposes an admission strategy for connection‐oriented services at the access node of a broadband integrated packet network based on asynchronous transfer mode. Based on an estimate of the probability of cell loss and in the absence of buffering, we determine the number of sources from different classes of bursty traffic which can be accepted. The parameters which are used to describe the traffic sources are average bit rate and peak bit rate. We will evaluate the cell loss estimate for homogeneous and heterogeneous cases. Furthermore, we will examine the variation of this estimate as the average to peak ratio changes. The estimate is an upper bound for the probability of cell loss. Based on this upper bound simple and robust allocation of resources to bursty sources can be developed. The proposed strategy can be implemented using simple computations or via a look‐up table to determine admission or denial of an incoming call and therefore allocating the required capacity. The procedure results in efficient use of the bandwidth, ensuring the desired service quality for connection‐oriented services and results in proactive control of network congestion.
A method for congestion control in atm networks using peak rate throttling
Authors: O'Neill Chris 
Published: July 2007

AbstractThis paper presents a technique, called peak rate throttling, for congestion control of controllable, variable bit rate traffic in ATM (asynchronous transfer mode) networks. It is much less conservative than techniques that have already been proposed. This is because techniques already proposed take no account of the load that is actually being carried by the network. Techniques already proposed assign a predetermined share of network capacity to connections regardless of what is actually being used. The technique proposed here works by throttling the peak bit rate that a user is allowed to send on a connection when the network detects a rising network load that may increase the cell loss rate of connections to greater than an acceptable limit. Users are still permitted to send whatever average bit rate they require, however. The technique relies on the assumption that the load offered to network links is stationary for a long enough period so that controlling action does not need to be performed too often or too quickly.It is feasible to achieve congestion control of a network using peak bit rate throttling alone and no other technique apart from connection control.
Performance trade‐offs in input/output buffer design for a non‐blocking space‐division packet switch
Authors: Lee Myung Jong , Li San‐Qi 
Published: July 2007

AbstractPerformance trade‐offs in buffer architecture design for a space‐division packet switching system is studied. As described in Figure 1, the system is constructed by a non‐blocking switch fabric and input/output buffers. The capacity of the non‐blocking switch fabric is defined by the maximum number of packets, denoted bym, which can be simultaneously routed from multiple inputs to each output. The buffer size at each input is considered to be finite, equal to K. The emphasis here is placed on the input packet loss probability for systems constructed by differentmsandKs. From the performance point of view, we conclude:choosingm= 3 or 4 is sufficient to exploit the maximum utilization of a non‐blocking switch fabricintroducing input buffers of moderate sizeKsignificantly reduces the packet loss probability.
The consumer electronic bus: An integrated multimedia lan for the home
Authors: Hofmann J. 
Published: July 2007

AbstractThe consumer electronic bus, or CEBus is a multi‐media LAN standard for the home which is now being finalized in North America by the Electronics Industry Association's Consumer Electronic Bus Committee (CEBC). The CEBus consists of media with data channels, and a control channel. The control channel is used for allocating the use of the data channels and for carrying short messages, whereas the data channels are used to carry various signals which do not fit the control channel. The control channel is digital, whereas the data channels can carry signals of any type.The physical layers for six media are at present defined in the standard: the power line, twisted pair, coaxial cable, infrared, low‐power RF, and a shielded cable bundle. An effort to define the physical layer for the seventh medium, optical fibre, was started at the end of 1989.The data link and network layers are fully implemented, whereas the transport, session and presentation layers are null. The application layer is fully implemented, including a command language which is used to facilitate easy interaction between competitor's products from the same consumer product sector, and between those from different sectors.
Customer network configurations and generic flow control
Authors: Händel Rainer , Huber Manfred N. 
Published: July 2007

AbstractThis paper analyses the BISDN customer network configurations as specified in CCITT Recommendation I.413 (e.g. star, bus, ring, starred bus), assumed market needs and the impact on the ATM layer functionality at the broadband user‐network interface at the SBand TBreference points. Orderly and fair access of several terminals to a shared transmission medium requires a suitable access protocol (generic flow control). Its functionality and possible implementations are discussed.
A multiservice GFC protocol
Authors: Adams J. L. 
Published: July 2007

AbstractGeneric flow control (GFC) is used to provide controlled transmissions from terminals over the BISDN user‐network interface. The reason for requiring controlled transmission is to allow for the multiplexing of cells from a number of terminals connected in either a dual bus or star configuration.GFC must provide fair access for each terminal, and the meaning of this is discussed for different services. It must provide a guaranteed minimum bandwidth, meeting the requirement of fair access for constant bit‐rate terminals. It must also provide fair access for variable bit‐rate (VBR) terminals. It is proposed that all terminals of a given class are given the same percentage reduction of their agreed peak bandwidths during overload conditions, leading to approximately similar delay distributions within the class. GFC can then be considered as providing a given quality of service per terminal (through guaranteed bandwidth) and an additional common quality of service for the unguaranteed cells.Some simulation results are provided for the dual bus configuration.
Distributed resource management and connection control for a multi‐access interface to a broadband ISDN (BISDN)
Authors: Kramer M. , Shtirmer G. 
Published: July 2007

AbstractA customer premises network (CPN) provides a common communications fabric to efficiently integrate the traffic of multiple terminals on a common access interface to a BISDN. An important consideration in choosing a CPN architecture is to facilitate terminal portability and applicationtransparency, so as to accommodate standard broadband terminals and applications, requiring only minor modification to adapt them from the standard BISDN interface to the multi‐terminal environment. This paper explores the multi‐faceted issues of CPN transparency with an emphasis on the evolving BISDN control and management architecture.We introduce a control architecture that conforms to a rigorous separation between ‘call control’ and ‘connection management’. This allows the CPN to be transparent to the user to network signalling exchange, and to participate only in the connection management via a remote resource management protocol. More generally, this scheme allows a call control entity located in a local exchange node (LEN) to manage a distributed set of resources such as switches and multiplexors (and CPNs). This is achieved through the definition of a standard interoperable interface between the central call control entity and the connection control entities which may be remotely located in various network elements. The features and functionality for such an interface, which we term the bearer connection control interface, are described within the framework of the OSI remote management architecture.A standard remote resource management protocol allows for the co‐operative sharing of resources across administrative domains. Although the importance of such a scheme is particularly visible as applied to remote CPN management, it is useful in other application domains where it is advantageous to distribute management processes.