bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renormalization of Quantum Electrodynamics in an Arbitrarily Strong Time Independent External Field
Authors: Dosch H. G. , Müller V. F. 
Published: July 2007

AbstractExtending the inductive renormalization procedure of Epstein and Glaser which is essentially based on locality, we show that quantum electrodynamics in an external time independent electromagnetic field has a renormalizable formal perturbation expansion. The interaction involving the quantized radiation field but not the action of the external field is treated by perturbation theory. It turns out that vacuum polarization is undetermined in the framework of such a theory.
Solitons and Confinement
Authors: Swieca J. A. 
Published: July 2007

AbstractThe Thirring and the Schwinger models both massless and massive are discussed as prototypes for theories with topological quantum numbers and confinement respectively.Bosonization of the fermion field is introduced from the beginning allowing a unified treatment of various models. An analysis of their charge sectors clarifies the relation between the periodicity of the potential in the bosonized version of those models and the existence of an additive quantum number.A brief outline of the essential features discussed which may survive in 4‐dimensional space‐time is made in the last section.
Fiber Bundles in Non‐relativistic Quantum Mechanics
Authors: Moylan P. 
Published: July 2007

AbstractThe problem of describing a quantum mechanical system with symmetry by a fiber bundle is considered. The quantization of a fiber bundle is introduced. Fiber bundles for the Kepler problem and the rotator are constructed. The fiber bundle concept provides a new model for a physical system: it provides us with a model for an elementary particle with extension having integral values of spin.
Fock‐Space Methods for Identical Classical Objects
Authors: Grassberger P. , Scheunert M. 
Published: July 2007

AbstractFock‐Space (annihilation/creation operator) methods are introduced to describe systems of identical classical objects. Specific examples to which this formalism is applied are branching processes (including age dependent ones), chemical reactions, deterministic (Hamiltonian) systems, and generalized kinetic equations. Finally, a generalization to stochastic quantum systems is proposed which is applied to a gas of spinning molecules.
Two‐Dimensional Field Theories
Authors: Berkov A. V. , Nikitin Yu. P. , Rosental I. L. 
Published: July 2007

AbstractQuantum field theories in space with the dimensionality 1 + 1 are considered. Quantum electrodynamics, quantum chromodynamics, sufficiently nonlinear models (with soliton solutions) and gravitational theory are discussed from the common viewpoint.The possible correspondence of two‐dimensional field models to physical reality is analyzed.
A Survey of Polarization Asymmetries Predicted by QCD
Authors: Baldracchini F. , Craigie N. S. , Roberto V. , Socolovsky M. 
Published: July 2007

AbstractWe give a comprehensive review of the polarization asymmetries predicted by QCD and the parton model for hard processes. The article discusses the interrelation between these processes which include deep inelastic inclusive, massive lepton pairs, reflected and transmitted asymmetries in hadron production at large pT, prompt photon production, etc. We also discuss the validity of the formulae derived and the potential effects of non‐leading logarithmic and power orders.
An empirical bayes strategy for analysing manufacturing data in real time
Authors: Sturm George W. , Feltz Carol J. , Yousry Mona A. 
Published: July 2007

AbstractThis paper discusses and develops a real‐time strategy to monitor manufacturing process control data. The strategy presented in this paper is designed to intercept, analyse and monitor data as measurements are generated from a high‐volume information‐intensive manufacturing process. Empirical Bayes theory is used to develop a method to monitor and analyse continuous type measurements generated by a manufacturing process in real time. Several specific techniques will be proposed for detecting manufacturing process problems and examples of applying these techniques will be shown.
ESD induced degradation mechanisms of InGaAsP/InP lasers
Authors: Magistrali F. , Sala D. , Salmini G. , Vanzi M. , Fantini F. , Giansante M. , Zazzetti L. 
Published: July 2007

AbstractThe sensitivity of InGaAsP/InP buried crescent lasers to ESD phenomena was deeply analysed, starting from the need to explain and prevent sudden failures during equipment manufacturing and test. Failure analysis allowed us to localize the degradation, which can be explained by means of a simple phenomenological model; finally a physical model was implemented trying to correlate the results of the failure analysis with the proposed failure mechanism.
A method of identifying latent human errors in work systems
Authors: Nakajo Takeshi 
Published: July 2007

AbstractWork system improvements are implemented in various manufacturing processes to prevent problems caused by human errors. However, they are almost always applied to problems which have already occurred. This paper examines a method of identifying latent human errors existing within the work systems beforehand. A procedure for applying failure mode and effect analysis to this identification problem was defined based on over 1000 empirical errors: a work system decomposition criterion and fundamental error modes for listing latent human errors, and then applied to three practical manufacturing processes in order to evaluate its effectiveness.
Operational life testing of power transistors switching unclamped inductive loads
Authors: White G. L. 
Published: July 2007

AbstractThis paper describes three types of high voltage power transistors that are in widespread use in the electronics industry today, and their susceptibility to reverse‐biased second breakdown while switching unclamped inductive loads. It provides a brief explanation of the phenomenon of second breakdown in transistors under both forward‐biased and reverse‐biased conditions. It describes a stress circuit that has been developed to incorporate switching of unclamped inductive loads as an integral part of operational life testing. A case history incorporating this technique is presented for the 2SD1739 high voltage NPN bipolar power transistor.
Numerical differences in the survival probabilities obtained by the cumulative‐hazard and kaplan–meier estimators of the reliability function
Authors: Bohoris G. A. 
Published: July 2007

AbstractThe paper examines two very important non‐parametric estimators of the reliability function which are frequently used in reliability practice to estimate survival probabilities. The paper proves that when both of them are calculated for the same data set, the survival probabilities obtained using the cumulative hazard approach are larger in magnitude than the ones given by the method proposed by Kaplan and Meier, and provides the mathematical formula quantifying the magnitude of this difference.
Component lifetime modelling
Authors: Verweij J. F. , Brombacher A. C. , Lunenborg M. M. 
Published: July 2007

AbstractThere are two approaches to component lifetime modelling. The first one uses a reliability prediction method as described in the (military) handbooks with the appropriate models and parameters. The advantages are:
It takes into account all possible failure mechanisms.
It is easy to use.
The disadvantages are:
It assumes a constant failure rate which is often not the case (infant mortality).
It contains no designable parameters and therefore it cannot be used for built‐in reliability.
The second approach is to model the different degradation mechanisms and to incorporate this into an (existing) circuit simulator. Here we have also advantages and disadvantages which are mostly complementary to those of the first method.
Observation of submicronic contacts and vias by scanning ion and electron microscopy
Authors: Pantel R. , Mascarin G. , Gonchond J. P. , Lafond D. 
Published: July 2007

AbstractScanning ion and electron microscopy of focused ion beam cross‐sections has been used to observe 0·6 μm contacts and 0·7 μm vias of a 0·5 μm CMOS technology. Three different kinds of cross‐sections have been tested to improve the observation quality. The comparison of images obtained with ions and electrons provides information on ion and electron contrast mechanisms. This technique has been used to identify very small defects in interconnection structures and to evaluate the 0·5 μm CMOS metallization process.
Study on reliability modelling of a hydraulic excavator system
Authors: Majumdar S. K. 
Published: July 2007

AbstractThe failure patterns of a well‐known brand of a hydraulic excavator system used in different environments were modelled adequately with an NHPP (non‐homogeneous Poisson process) having time‐dependent log‐linear peril rate functions. Using the fitted model, the reliability of the excavator system was estimated in different environments (cement plant, coal mine, iron ore mine, etc.). The system reliability was found to be very poor during the initial phase of operation and gradually improved with an increase in cumulative operating hours regardless of change in environment. Notwithstanding this general trend, the system reliability differed significantly in different environments for any given duration of operation and was particularly very poor in cement plants. With the help of the FMEA technique, high risk prone failure modes of the excavator system of the given model were identified and appropriate corrective measures were initiated. The failure patterns of the modified excavator system changed regardless of environment, so much so that an HPP (homogeneous Poisson process) model with constant peril rate could be fitted adequately to characterize the failure pattern of the system. The system reliability improved considerably in the initial phase of operation since start‐up.
Computer simulation for quality and reliability engineering
Authors: Robinson Stewart , Higton Neil 
Published: July 2007

AbstractComputer simulation has been used widely in many industries for many applications. A simulation model mimics a real world system, enabling an investigation of its operation. More recently simulation models have incorporated a visual display and interactive features to aid understanding and enhance the investigation. Computer simulation has many potential uses in quality and reliability engineering, for instance, modelling equipment failures, quality control strategies, maintenance requirements and operational logistics. A case study shows how simulation has been used to study the throughput, flexibility and robustness of a manufacturing plant design. Alternative simulation software packages are briefly discussed.
Determination of human error patterns: The use of published results of official enquiries into system failures
Authors: Bradley Edgar A. 
Published: July 2007

AbstractOfficial enquiries into large scale system failures may be used to interpret events according to the various types of human error which were committed. For example there are errors in operation of the system, in maintenance practices etc. Twelve well documented disasters are analysed and the conclusion emerges that operator error predominates. This fact is not suprising, reflecting as it does the short time span in which operators have to make decisions, compared to the other players such as designers, maintenance men etc.This conclusion has implications for the other human disciplines involved. For example designers should conceive systems which will be less prone to operator error, while management should support operators in whatever way possible to increase their effectiveness.
Practical multiprocessor scheduling algorithms for efficient parallel processing
Authors: Kasahara Hironori , Narita Seinosuke 
Published: July 2007

AbstractThis paper describes practical optimization/approximation algorithms for scheduling a set of partially ordered computational tasks with different processing times onto a multiprocessor system so that the schedule length is minimized. Since this problem belongs to the class of “strong” NP hard problems, we must eliminate the possibility of constructing not only pseudopolynomial time optimization algorithms, but also fully polynomial time approximation schemes unless P = NP.This paper proposes a heuristic algorithm CP/MISF (Critical Path/Most Immediate Successors First) and an optimization/approximation algorithm DF/IHS (Depth First/ Implicit Heuristic Search). DF/IHS is an excellent scheduling method which can reduce markedly the space complexity and average computation time by combining the branch‐and‐bound method with CP/MISF; it allows us to solve very large‐scale problems with a few hundred tasks.
Real‐time edge detection of fish school echo image by two‐dimensional exponential smoothing
Authors: Shigeyasu Kuniyuki , Ogasawara Motoyasu 
Published: July 2007

AbstractThe boundaries of fish school echo image, which is usually displayed in black and white shades, are not well defined and the necessity for clear edge display has long been felt. Edge detection is also important in the continuous recognition of the sea bed or in the measurement of the school size. Unfortunately, a typical echo sounder image fluctuates severely, prohibiting edge detection with the original image. We propose an edge detection method in which the image is smoothed first by the two‐dimensional exponential smoothing method, and the difference of expected values of data obtained during this processing is compared with a given threshold value to determine the edge. Three ways of taking the difference are conceivable, namely, difference in the radial direction, in the lateral direction, and in the oblique direction; each may be considered as the difference of two‐dimensional data or a weighted slope average. The proposed method effectively performs the conventional smoothing by masking and the edge detection by Laplacian processing simultaneously. Thus, real‐time edge detection of school or sea bed images has become possible in a simple way. This paper describes the theory of edge detection by the above three methods and compares their effectiveness.
Automated extraction of cancer lesions with convergent fold patterns in double contrast x‐ray images of the stomach
Authors: Hasegawa Jun‐Ichi , Tsutsui Taketoshi , Members Jun‐Ichiro Toriwaki, 
Published: July 2007

AbstractThis paper describes an automatic detection system which extracts pathological areas from double contrast stomach x‐ray images developed for computer‐assisted diagnosis of stomach x‐ray images. This paper examines the image for stomach cancer, especially the convergent fold pattern of the stomach wall which is inherent to the early stage of cancer, and extracts the pattern from the x‐ray image.The actual processing procedure is divided largely into the following four stages: (1) extraction of the border of the fold region; (2) extraction of contrasted regions of the bowel; (3) evaluation of the fold convergence; and (4) extraction of the lesion candidates.In this paper, a new feature parameter called convergence index is defined to represent quantitatively the extent of convergence of the folds on the stomach wall. The detailed computation procedures for the convergence index are presented. Finally, an experiment is presented for the actual 25 examples of double contrast stomach x‐ray images, and it is demonstrated that the proposed system has a fairly high detection performance for the cancer lesion with fold convergence. No study has been presented on the recognition of the pathological pattern for the stomach cancer in the double contrast stomach x‐ray image, and the result in this paper is expected to provide an important clue to the realization of the future automatic diagnosis of the stomach x‐ray images.
3‐D object recognition using functional models
Authors: Yamamoto Tsutomu , Kato Hirokazu , Sato Kosuke , Inokuchi Seiji 
Published: July 2007

AbstractMany human activities are based on visual recognition of a scene. Development of scene recognition capability on computer is essential to the development of an intelligent robot.This paper proposes a three‐dimensional (3‐D) object recognition system using functional models. In conventional geometric model‐based recognition, one reference model must be provided for each possible object shape in the same category. This paper proposes a functional model that will allow flexibility in representation of objects belonging to the same category.Experiments were conducted to provide measurement data for demonstrating this functional model‐based object recognition technique. Scene segmentation uses both gray scale image and range image to provide superior segmentation results. The performance of a functional model‐based method for recognizing objects with different shapes that belong to the same functional category is demonstrated.
The Economic Status of A Timurid Sufi Shaykh: A Matter of Conflict or Perception?
Authors: Gross Jo-Ann 
Published: July 2007

The word “Sufi” is believed by some to be derived from the word “suf,” denoting a kind of woolen garment worn by ascetics. The wearing of this garment symbolizes the Sufi's renunciation of material, worldly concerns and his complete absorption in God. Throughout the history of the Sufi orders, this symbol of the humble woolen cloak has often stood in contrast with the actual economic status attained by many Sufi shaykhs. In her bookMystical Dimensions of Islam,A. Schimmel drew attention to this contrast:The history of the political role assumed by mystical leaders in Islamic communities has still to be written. And one enigma remains to be resolved: how so many of those who preached poverty as their pride became wealthy landlords and fitted perfectly into the feudal system, amassing wealth laid at their feet by poor, ignorant followers.
ALCOHOL AND PEPTIC OESOPHAGITIS
Authors: Foy A. , Duggan J. M. 
Published: July 2007

AbstractThe alcohol intake of a series of 27 unselected patients with oesophagitis was compared with that of a matched control group. Men with oesophageal disease drank significantly more than controls, but no such relationship was demonstrated for women. In a parallel study, the stated alcohol take of 41 unselected patients with benign oesophageal stricture was compared with that of a matched control group. Males drank more alcohol than controls to a clinically and statistically significant degree, but in females the differences were minor. Treatment must include a consideration of the patient's alcohol intake, especially in males.
PRECIPITANTS OF ALCOHOLIC RELAPSE: THE FUNCTIONAL ANALYSIS OF 100 CASES
Authors: Maxwell D.J. 
Published: July 2007

AbstractAlcoholic relapse was investigated in 100 subjects, patients in a residential treatment program, by the analysis of responses to a semi‐structured interview. The use of the AMIS (Amissions Meeting Interview Schedule), constructed for the purposes of this study, is described.A focus of the research was to identify those events or situations which precipitate resumption of drinking in abstinent alcoholics following treatment, and to ascertain the relative danger of each as a potential precipitant of relapse. Relapse precipitants were found to be more diverse and more complex in their contribution to the process of relapse than has previously been acknowledged.The results support a ‘coping skills’ model of relapse, and argue for a radical change of current treatment practices towards a ‘relapse prevention’ approach.
OUTPATIENT DETOXIFICATION IN HEROIN USERS — A COMPARISON OF A HEMINEURIN AND A CLONIDINE REGIME
Authors: Batey R. 
Published: July 2007

ABSTRACTHeroin using clients often demand help to detoxify from their drug habit but for a variety of reasons, resist inpatient care. This paper reports methods and results employed at Westmead Drug and Alcohol Units in outpatient detoxification. It is demonstrated that heroin detoxification can be successfully achieved in an outpatient setting for carefully selected patients, with a low dropout rate and few complications with daily attendance, using either of two different drug regimes.
Integrins and Regulation of the Microcirculation: From Arterioles to Molecular Studies using Atomic Force Microscopy
Authors: MARTINEZ‐LEMUS LUIS A. , SUN ZHE , TRACHE ANDREEA , TRZCIAKOWSKI JEROME P. , MEININGER GERALD A. 
Published: July 2007

ABSTRACTIntegrins are an important class of receptors for extracellular matrix proteins that can mediate both force transmission, by virtue of their connections with the cell matrix and cytoskeleton; and signal transduction, resulting from the assemblages of signaling proteins that associate with focal contacts. Consequently, integrins have been proposed to be the mechanosensor in vascular smooth muscle and endothelial cells and to play a central role in mechanotransduction. In this regard, mechanical force is an important stimulus for many vascular functions, including contractile and relaxation processes, proliferation, migration, attachment, and cell phenotype determination. Collectively, these functions define physiological properties of the vasculature such as control of blood flow, capillary pressure, permeability, and peripheral vascular resistance, and play a role in pathophysiological processes like hypertension, diabetes, and arteriosclerosis. Our knowledge concerning how integrins sense and transduce physical forces into cellular signals and which integrins are involved is incomplete. Compared to other cell surface receptors, integrins have a relatively low affinity for their binding sites on the extracellular matrix and their affinity can be regulated. These characteristics of integrin–ligand interaction may facilitate dynamic processes such as cell migration, cell remodeling, and contractile activation in response to external forces. Important questions remain concerning the nature and origin of integrin‐mediated signaling in the vascular wall.
Neurovascular Alignment in Adult Mouse Skeletal Muscles
Authors: BEARDEN SHAWN E. , SEGAL STEVEN S. 
Published: July 2007

ABSTRACTObjective: Muscle blood flow increases with motor unit recruitment. The physical relationships between somatic motor nerves, which control muscle fiber contraction, and arterioles, which control microvascular perfusion, are unexplored. The authors tested the hypothesis that motor axons align with arterioles in adult skeletal muscle.Methods: Transgenic mice (C57BL/6 background, n = 5; 10 months of age) expressing yellow fluorescent protein in all motor nerves underwent vascular casting (Microfil). Excised epitrochlearis, gracilis, gluteus maximus, and spinotrapezius muscles were imaged at 380× and 760× and a computer‐integrated tracing system (Neurolucida) was used to acquire 3‐dimensional digital renderings of entire arteriolar and neural networks within each muscle.Results: Arteriolar networks were typically ∼3‐fold longer than neural networks. Nerves coursed with arterioles until terminating at motor endplates. Across muscles, proximity analyses revealed that ∼ 75% of total nerve length (9.8–48.8 mm) lay within 200 μm of the nearest arteriole (diameters of 15–60 μ m).Conclusions: Somatic motor nerves and arterioles align closely within adult mammalian skeletal muscle. Understanding the signals governing neurovascular alignment may hold important clues for the advancement of tissue engineering and regeneration.