bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infrateilchen in der Quantenfeldtheorie
Authors: Schroer B. 
Published: July 2007

AbstractIt is shown that in the presence of zero restmass particles the spectral assumptions of Quantum field theory have to be modified. Particles coupled to zero rest mass particles may not be eigenstates of the mass operator. In such a case the usual asymptotic condition is not valid and the Hilbertspace has an entirely different structure from the Hilbertspace of “normal” quantum field theory. Quantumelectrodynamics provides an example for this situation. The electron is an “infraparticle”, i. e. an “almost” discrete eigenstate of the mass operator.
Zur heuristischen Begründung der Feldgleichungen freier Teilchen
Authors: Langbein Werner 
Published: July 2007

AbstractFalls nicht ausdrücklich anders definiert, bezeichnen große Buchstaben Operatoren, die entsprechenden kleinen Buchstaben deren Eigenwerte. Räumliche Vektoren sind durch fett gedruckte (d. h. etwa der Impuls durch p), Vierervektoren durch einfache Buchstaben (d. h. etwa der Viererimpuls durch p) gekennzeichnet. Bei Verwendung der Indexschreibweise sollen lateinische Indizes von 1 bis 3, griechische von 0 bis 3 laufen. Über doppelt auftretende Indizes ist stets zu summieren.
Group Dynamics of Elementary Particles
Authors: Kleinert Hagen M. 
Published: July 2007

AbstractIt is proposed that particle interactions can be described by means of simple group operations in non‐compact Lie groups. Prescriptions for the structure of these group operations are formulated which are motivated by the study of simple models, in particular of the dynamics of the hydrogen atom. If they are fulfilled we call the structure “group dynamics”.Neglecting at first internal symmetries, a few simple models are investigated in which group dynamics is possible. The group O(3,1) turns out to describe the coupling of pseudoscalar mesons, O(4,2) that of photons to baryons quite well: The pionic decay rates of baryon resonances up to spin 19/2 and the electromagnetic form factors of the nucleons are predicted in good agreement with experiment.The internal symmetry SU(3) is included in the O(3.1) model of the pionic coupling in the simplest way, by assuming O(3,1) × SU(3) to be the dynamical group. This gives rise to a minimal symmetry breaking of the amplitudes and relates it to the mass differences in SU(3) multiplets: The amplitude consists of a product of a SU(3) Clebsch Gordan coefficient and a universal function of the velocity of the final baryon. The way the particle masses enter the decay rates is uniquely prescribed in this approach. The agreement with experiment is excellent.Finally, the connection of this purely algebraic approach with related ideas, like the use of infinite component wave equations, is discussed.
The Boson Method for Anisotropic Superconductors
Authors: Matsumoto H. , Tachiki M. , Umezawa H. 
Published: July 2007

AbstractIn this paper a rigorous derivation of the boson method for anisotropic superconductors is presented. A most general form of macroscopic equations for the current and magnetic field is obtained from the assumption that the Lagrangian is gauge invariant. We then proceed to explain what kind of approximations can be introduced in order to simplify these macroscopic equations. We formulate the results in a form convenient for analysing the magnetic properties of anisotropic superconductors. An improved version of analysis for the vortex normal‐core energy is also presented.
Vacuum Stress‐Energy Tensor and Particle Creation in Isotropic Cosmological Models
Authors: Grib A. A. , Mamayev S. G. , Mostepanenko V. M. 
Published: July 2007

AbstractQuantum theory of quantized scalar and spinor fields in homogeneous isotropic space‐time is considered. Particle interpretation of quantized field is given which is based on diagonalization of the Hamiltonian constructed by means of the metrical stress‐energy tensor (SET). This interpretation allows to define a normal ordering prescript which respects the conservation property of SET. With the help of Zeldovich‐Starobinsky regularization procedure [3] this allows to obtain the total renormalized vacuum expectation values of SET which include both nonlocal terms corresponding to the particle creation and local ones describing the vacuum polarization. Estimates for the total SET of scalar and spinor field on various stages of the evolution for realistic cosmological models are obtained. Also the effect of spontaneous breakdown of gauge symmetry for selfinteracting scalar field in a hyperbolic Friedman model is considered.
An alternative to the analysis of variance for reliability data
Authors: Edgeman Rick L. 
Published: July 2007

AbstractThough the analysis of variance is a commonly applied method for testing for differences between means of several processes, it is based in part on the assumption that the processes give rise to output that is normally distributed on the measured variable. Reliability and life test studies frequently give birth to data that exhibit clear skew, and application of the analysis of variance is questionable in such cases. A method referred to as analysis of reciprocals, which is based on an assumed inverse Gaussian distribution, provides an alternative to the analysis of variance in these instances.With applications in a variety of functional areas, including reliability and life testing, the inverse Gaussian distribution is able to accommodate substantial skew. It is hoped that this exposition will increase awareness of both the inverse Gaussian distribution and data analysis methods that are based on this distribution.
USING STEP STRESS TO EXPLORE THE KINETICS OF FAILURE
Authors: Luvalle M. J. , Hines L. L. 
Published: July 2007

AbstractIn this paper a case study is presented illustrating a new step stress experiment design and associated graphical techniques for analysing failure data. The design and analysis procedures probe the process causing failure and suggest models for the kinetic processes underlying failure. The resulting kinetic models can be used to extrapolate the high stress behaviour to operating conditions.This case study concerns a failure mode observed at accelerated stresses in epoxy glass printed wiring boards. This failure mode has been found to be impossible to analyse using simple acceleration factors. The procedure described here quickly reveals this fact and indicates what kind of kinetic model is consistent with the observed data. The resulting qualitative model agrees with the results of independent physical experiments, and field experience.
Computer simulation of fast electromigration lifetime determination techniques
Authors: Gilfedder T. H. , Jones B. K. 
Published: July 2007

AbstractThe electromigration lifetime and the activation energy of the process are often determined by highly accelerated or fast methods. Some of these common methods have been simulated using a crack model of the defect. The TRACE, BEM and WIJET methods are considered and suggestions are made about the optimum test strategy.
Analysis of HBM ESD testers and specifications using a fourth‐order lumped element model
Authors: Verhaege Koen , Roussel Philippe J. , Groeseneken Guido , Maes Herman E. , Gieser Horst , Russ Christian , Egger Peter , Guggenmos Xaver , Kuper Fred G. 
Published: July 2007

AbstractThis paper presents the general and analytical solution of a fourth‐order lumped element model (LEM) to describe human body model (HBM) electrostatic discharge (ESD) testers including the main tester parasitic elements. The analytical fitting to the LEM of experimentally obtained HBM pulse data is a new scientifically justified tool to determine HBM tester parasitic elements. The impact of the test board capacitance on HBM testing is demonstrated and explained. Furthermore, the MIL 883C/3015.71 and EOS/ESD S5.1‐19912 Standards on HBM testers are evaluated upon their selectivity to the test board capacitance. Finally, recommendations to improve HBM tester specifications regarding their selectivity to the parasitic test board capacitance are formulated
Improving quality in iron casting by optimizing sand recycling
Authors: Sweeting F. B. J. , Thorpe W. R. , Pettitt A. N. 
Published: July 2007

AbstractTwo previous studies of the application of the techniques of information technology and statistics to the relatively low‐level records of a semi‐automated iron foundry have been made. Each has contributed to better knowledge and understanding of variables of the casting process, in the course of solving a specific problem. Encouraged by the enthusiasm for and quality of record keeping evident during the studies, it was decided to use the same investigative approach to make a deliberate search for any opportunity that might exist for improving the quality and/or productivity of green sand moulding.Data collected over a period of ten weeks were analysed under four broad headings: products, input materials, process operations and control of process variables. A comparison of production figures from the start and finish of the datum period revealed a reduction in the mould rejection rate of 40 per cent with reductions in inputs of new sand and bentonite of 42 and 12 per cent, respectively. The seemingly onerous task of good process record keeping had proved to present an opportunity in disguise.
A data acquisition system for machine tool condition monitoring
Authors: Drake P. R. , Jennings A. D. , Grosvenor R. I. , Whittleton D. 
Published: July 2007

AbstractA flexible, generically applicable and inexpensive data acquisition system (DAS), for machine tool condition monitoring, has been designed, constructed and installed as part of a European Union sponsored project. The DAS is more than just a data logger and an array of sensors. It also consists of a methodology for analysing data logging requirements and a relational database that supports this methodology. The database is held on a central ‘maintenance management’ computer. The monitoring to be carried out by the DAS is specified through this database, which contains detailed information about the DAS's facilities. This feature makes it simple to reconfigure the DAS to implement new monitoring requirements and to customize its operation to meet the needs of different machines. The information in the database is transformed into a look‐up table that is read by the software that sets up and controls the data logging processes.
A consumer incentive warranty policy and servicing strategy for products with uncertain quality
Authors: Murthy D. N. P. , Djamaludin I. , Wilson R. J. 
Published: July 2007

AbstractOwing to quality uncertainty in manufacturing, some of the items produced can be non‐conforming. When items are sold with warranty, the warranty servicing cost for non‐conforming items can be high. Life testing can be used to weed out such items and reduce the warranty cost. Such testing is expensive in terms of time and money. Releasing items with no testing can result in an increased number of early failures which in turn leads to consumer dissatisfaction and affects future profits, due to a loss of consumers. We propose a new policy which involves no testing and incorporates an incentive feature to reduce consumer dissatisfaction.
An alternative method to test for randomness of a process
Authors: Holmes Donald S. , Mergen A. Erhan 
Published: July 2007

AbstractThe objective of this paper is to revisit an old technique for testing the randomness of a process. This method uses the mean square successive difference approach to estimate variance, compares this estimate with the usual variance estimate, and tests whether the two variance estimates are significantly different. If the test result is significant, it is concluded that the process is not random (i.e. not in control). The non‐random results are addressed to accomplish quality improvement.
An efficient encoding method for electrocardiography using spline functions
Authors: Imai Hidekl , Kiraura Nobuyoshi , Yoshlda Yutaka 
Published: July 2007

AbstractThis paper proposes a highly efficient encoding method for electrocardiogram using spline functions. The method consists of the extraction algorithm, which extracts feature samples from the electrocardiogram from the A/D converter, and the restoration algorithm which restores the original waveform from the extracted samples, using spline functions. In the extraction algorithm, maxima and minima, which is not due to noise, are extracted from the original waveform. Then the spline function is applied to perform a smooth interpolation. By this scheme, a highly accurate approximation is realized, which has not been achieved by the linear approximation using the traditional AZTEC method. According to the result of experiment, the root‐mean‐square error of the proposed method is approximately half the AZTEC method if the compression ratio is the same. The proposed method consists in the simple extraction algorithm, and can be implemented on a microprocessor. Thus, it is suited to the long‐term monitoring of the electrocardiogram to record abnormal waveforms.
A widely applicable configuration method for communication control equipment—Degeneration of parallelism in communication control processing
Authors: Yamashita Masahide 
Published: July 2007

AbstractThis paper proposes a configuration for a communication control system with a wide range of applications. The proposed configuration is based on the degenerate realization of serial processing (without any restriction of the order) and time‐division processing of seven kinds of parallelism included in the communication control processing, as well as on the degenerate realization by shared network bus for the processing request (token) transfer among the components. By the proposed eight kinds of standard configurations, a unified design is made for a wide range of performance from the terminal level to the communication control in a large‐scale preprocessing device. The serial processing realized by extracting the protocol‐dependent (level) functions and the programmed control provides a flexible means to cope with a wide range of requirements for such functions as odd or delete kinds of links and protocols. This paper outlines the eight kinds of standard configurations and the principle of selection among those together with the derivation of the proposed configurations.
Hierarchical properties of the κ ‐neighborhood template A‐type 2‐dimensional bounded cellular acceptor
Authors: Taniguchi Hiroshi , Inoue Katsushi , Takanami Itsuo 
Published: July 2007

AbstractThis paper discusses the hierarchical properties of the κ‐neighborhood template A‐type two‐dimensional bounded cellular acceptor (abbreviated as A‐2BCA(κ) on three‐dimensional tapes we proposed previously. An A‐2BCA(κ) is a three‐dimensional automaton which consists of a pair of a converter and a configuration‐reader. The former converts the given three‐dimensional tape to the two‐dimensional configuration and the latter determines the acceptance or nonacceptance of given three‐dimensional tape whether or not the derived two‐dimensional configuration is accepted.We investigate how the difference of the neighborhood template of the converter or the configuration‐reader affects its accepting power. As a result, it is shown that when the converter is deterministic, the greater the number of neighbor cells of the converter and the more powerful the configuration‐reader, the more powerful the accepting power of the A‐2BCA(κ). However, this is not always true for the nondeterministic case. As far as this case is concerned, the following results are obtained:(1) Nine‐neighbor is as powerful as five‐neighbor whatever the configuration‐reader combined;(2) there exist classes of two‐dimensional automata such that indeed their accepting powers are different, but those of A‐2BCA(κ) using these are identical.
A study on initial value setting of the back‐propagation learning algorithm
Authors: Jia Qi , Toda Naohiro , Usui Shiro 
Published: July 2007

AbstractThere is no known systematic method for setting the initial values of weights and thresholds for backpropagation learning in multilayer feedforward neural networks. Thus, the trial‐and‐error method of providing random numbers distributed evenly over a certain range has come to be commonly used.This paper defines characteristic parameters for a multilayer feedforward neural network to examine its information transmission capabilities and, using those parameters, clarifies the behavior of and problems with the conventional method using random initial values. One such problem is that the active range of a unit narrows rapidly as the number of inputs is increased. In view of this, a new method is proposed for determining initial values which expand the active range; and its usefulness is shown through numerical experiments.
Image restoration by averaged projection filter
Authors: Yamashita Yukihiko , Ogawa Hidemitsu 
Published: July 2007

AbstractA restoration filter called the averaged projection filter (APF) is proposed for the linear degradation model. The proposed filter selects the image with the least deviation of noise component from among those minimizing the image component of the restored image in the averaged sense with respect to a set of original images. With the plain projection filter, the frequency of occurrence of images is ignored. In the averaged projection filter, the restoration quality of images occurring more frequently is improved at the expense of those occurring less frequently. A general form of the filter is obtained by using functional analysis. Some experimental results are illustrated which show the advantages of the proposed filter over the projection filter and the Wiener filter.
Performance of the PN superscalar processor as estimated by simulation
Authors: Arita Takaya , Ito Hiroaki , Sowa Masahiro 
Published: July 2007

AbstractThe authors have already proposed the multiple instruction‐stream execution system by a function‐partitioned superscalar processor, for extracting the fine‐grain parallelism. In the proposed system, the processor is divided into a number of heterogeneous processing units and the instruction stream is given separately to the processing units. The processing units communicate the tokens (control pulses) at a higher speed to control the execution of instruction according to the precedence relations among the instructions.This paper considers the prototype model based on three kinds of machine instructions and evaluates the fundamental performances of the proposed execution scheme by simulation. Especially, the following items are examined: (1) load distribution by three kinds of instructions, (2) extracted parallelism and execution time of the program, (3) effect of token communication time and the effect of overlapped execution of token transmission/reception instructions, and (4) effect of access time of memory unit.
The Mechanism of Synovial Fluid Retention in Pressurized Joint Cavities
Authors: LU Y. , LEVICK J. R. , WANG W. 
Published: July 2007

ABSTRACTObjective: Hyaluronan (HA) in synovial fluid is vital to fluid retention in joint cavities. This study aims to evaluate a HA concentration polarization hypothesis and to examine, quantitatively, the agreement between theoretical predictions and experimental results.Methods: A non‐steady‐state model was developed for HA ultrafiltration and concentration polarization on the synovial surface. The Kedem‐Katchalsky equation was used to calculate the trans‐synovial filtration rate Q as the HA concentration polarization layer built up. Model parameters were based on data from experiments. Effects of parameters on fluid filtration were investigated.Results: The HA osmotic pressure at the synovial surface was found to approach the intra‐articular pressure, P, during fluid infusion. The model simulated the experimentally observed decay in Q with the time at constant P, and predicted nonlinear P‐Q relations in good agreement with experimental results over a range of bulk HA concentrations, from pathological (0.2 g L−1) to physiological (4.0 g L−1). It gave quantitative insights into the development of the osmotic pressure and the significance of the HA reflection coefficient.Conclusions: The osmotic pressure of a HA concentration polarization layer on the synovial surface leads to outflow buffering. This provides the mechanism by which the vital lubricating synovial fluid is retained in a joint cavity under pressure.
Differential Arterial/Venous Expression of NG2 Proteoglycan in Perivascular Cells Along Microvessels: Identifying a Venule‐Specific Phenotype
Authors: MURFEE WALTER L. , SKALAK THOMAS C. , PEIRCE SHAYN M. 
Published: July 2007

ABSTRACTObjective: Similar to other vascular pericyte markers, including smooth muscle (SM) α‐actin, desmin, and PDGF‐β‐receptor, NG2 proteoglycan is not pericyte specific. Therefore, the use of NG2 as a pericyte marker, especially in cell lineage studies, in comparison to other nonspecific pericyte markers requires an understanding of how its expression varies spatially within a microvascular network. The objective of this study was to characterize NG2 expression along vessels within rat microvascular networks and compare this to SM α‐actin expression.Methods: Mesenteric tissue, subcutaneous tissue, spinotrapezius muscle, and gracilis muscle were harvested from 250‐g, female, Sprague–Dawley rats and stained for NG2 and SM α‐actin. The distribution of NG2 expression was evaluated in mesenteric networks (n = 28) with complementary observations in subcutaneous tissue and skeletal muscle.Results: Perivascular cells, including mature smooth muscle cells (SMCs), immature SMCs, and pericytes, expressed NG2. Most importantly, NG2 expression was primarily confined to perivascular cells along arterioles and capillaries, and continuous expression was not observed along venules beyond the immediate postcapillary vessels. The differential expression of NG2 along the arteriolar side of microvascular networks was also observed in rat subcutaneous and skeletal muscle.Conclusions: The results indicate that NG2 is expressed by all perivascular cells along arterioles, and its absence denotes a venule‐specific phenotype. These results identify for the first time a marker that differentiates venous smooth muscle and pericytes from other capillary‐ and arteriole‐associated perivascular cells.
Special Edition of Microcirculation Commemorating the 50th Anniversary of the Microcirculatory Society, Inc.
Authors: SEGAL STEVEN S. , JACKSON WILLIAM F. 
Published: July 2007

ABSTRACTThis special edition of Microcirculation brings together the proceedings from the Symposium held in the spring of 2004 in the Natcher Auditorium on the campus of the National Institutes of Health to commemorate the 50th Anniversary of the Microcirculatory Society, Inc. Twelve brief reviews are introduced with the goals being to present a collective sense of the history of research in microcirculation, provide insight into where established topics of inquiry stand today, and to define emerging topics of investigation for future research efforts.