bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Partial Wave Crossing Relations to πN Scattering
Authors: Jakob H.‐P. , Krubasik E. , Steiner F. 
Published: July 2007

AbstractThe partial wave crossing relations derived in a recent paper by Steiner [1] are used for a calculation of the πN S‐wave amplitudes in the region 8 ≦ s ≦ (M − 1)2. The corresponding Argand diagrams show the pseudoresonance behaviour predicted in [1]. The results for the real parts are compared with an independent calculation using fixed‐t dispersion relations.
On the Connection between Particles and Poles of the S‐Matrix
Authors: Fonda L. 
Published: July 2007

AbstractIn axiomatic S‐matrix theory it is usually assumed that stable particles give rise to simple poles of the S‐matrix for real negative energies while unstable particles give rise to poles close to the real axis on an unphysical sheet of the energy Riemann surface. The stable particle — pole association has been known for a long time not to be always true. For example in potential scattering what is relevant in this case in fact is not the S‐matrix but the Jost function. The zeroes of this function for real negative energies are in fact in one‐to‐one correspondence with the bound states, while the correspondence may break down for the poles of the S‐matrix. On the other hand it has recently been pointed out that there also is in general no connection between unstable particles and poles of the S‐matrix.
Properties of Equilibrium States on Quasilocal C⋆‐algebras
Authors: Andersson Stig I. 
Published: July 2007

AbstractThese notes have grown out of a seminar series and are to a large extent of a review character (this goes especially for section 3).Novel aspects are indicated in connection with the continuous point particle systems and the relations between equilibrium conditions. We concentrate on some less often treated subjects, viz. the decomposition theory and equivalence of the equilibrium conditions.
Weak Neutrino‐Lepton Annihilation into Hadrons
Authors: Actor Alfred 
Published: July 2007

AbstractAn exploratory study of weak neutrino‐lepton annihilation into hadrons, v̄l + l → hadrons is presented. Simple cross‐section estimates indicate processes of this type may be observable in a large bubble chamber. We discuss the information one could hope to obtain from such experiments. General formulas for amplitudes and cross sections are given for v̄l + l → hadrons assuming a point‐like V – A interaction. To establish tests of the V – A interaction, we recalculate the annihilation amplitudes assuming a point‐like scalar‐pseudoscalar or tensor‐pseudotensor interaction. The extension to theories with intermediate vector bosons is sketched. We discuss the connection between v̄l + l → hadrons and e+e− → hadrons implied by the conserved vector current hypothesis. We note that in v̄l + l → rH, K⋆(890), A1, B creation (these reactions enjoy comparatively large cross sections) the leptonic as well as hadronic couplings of these J = 1, I = 1/2 or 1 mesons could be determined. A related possibility is the direct creation of new heavy charged J = 1 mesons. The normal J = 1 resonance region could be explored with neutrino energies of the order 500–2000 GeV. For this, and for higher‐energy work, a TeV proton accelerator is clearly necessary.
A Jet Model Study of Correlations in Hadron‐Hadron Reactions Due to Resonance Production
Authors: Biebl K. J. , Klein M. , Nahnhauer R. 
Published: July 2007

AbstractSecondary particle correlations are discussed as a basic feature of hadron induced multiparticle reactions in the 5 to 1500 GeV energy range.Two introductory sections are devoted to definitions of cross sections and to empirical regularities of multiple production. Many of these regularities can be understood to be consequences of energy‐momentum conservation and limited transverse momenta (uncorrelated jet model (UJM)). An extension of the UJM is considered, the correlated jet model (CJM), by introducing dynamical short range correlations between the particles which are assumed to be due to resonance production. Many properties of single‐particle distributions and correlation functions can be derived already from kinematics of resonance decay. The CJM is used to investigate in detail the origin of angular correlations (azimuthal, GGLP‐effect) and of correlations between neutral and charged particles (〈π°〉nc, f00(nc)). These correlations are shown to arise almost completely from the production and decay of mainly two‐particle resonances like ∂°, K* and Δ, the main evidence coming from the use of the invariant mass as the basic variable where only resonances or reflections of them give remarkable effects. Compared to the UJM, the CJM is the first approximation of a successive correlations analysis of the production amplitude squared, i.e. having separated the effects of energy‐momentum and quantum number conservation. This might be also interesting in view of the forthcoming accelerator generation.
First Quantum Corrections to the Classical Partition Function for a Non‐Relativistic Electrodynamical System
Authors: Ruiz F. Ruiz , Alvarez‐Estrada R. F. 
Published: July 2007

AbstractThe classical partition function for a system in thermodynamical equilibrium formed by N identical non‐relativistic particles interacting through Coulomb potentials and with the dynamical electromagnetic field is studied. It is proved that the dynamical or transverse EM degrees of freedom decouple from the particle ones. It is also shown that this decoupling does to take place in the quantum mechanical partition function. The leading quantum corrections to the classical partition function are explicitly given. Such corrections are shown to be determined by instantaneous dipole‐dipole coulombic interactions and by self‐energy effects, and to receive no contribution from the interaction among different particles mediated by the dynamical EM field.
Brans‐Dicke Cosmology with a Scalar Field Dependent Cosmological Term
Authors: Bertolami Orfeu 
Published: July 2007

AbstractWe propose a cosmology based on the Brans‐Dicke theory with a cosmological term dependent in the scalar field. It is shown the existence of a solution in a Robertson‐Walker metric that does not suffer from any unnatural fine tuning in the very early Universe such as the horizon, homogeneity, isotropy and flatness problems and does not present any difficulty concerning the GUTs magnetic monopoles.
Variation of defect density and its influence on yield extrapolation for integrated circuits
Authors: Kleppmann W. G. , Vollertsen R.‐P. 
Published: July 2007

AbstractUsing the example of stress tests for dielectric breakdown, the close relation between the local variation of defect density on the one hand and the area dependence of yield is verified directly.There is appreciable real variation of defect density (in addition to purely statistical fluctuation) even within individual wafers, but also additional variation between wafers processed together in groups and further variation again between groups of wafers processed separately. Correspondingly, the dependence of yield on area differs progressively more from the Poisson model as more (different) data are summarized in a single average yield.The local variation of defect density also depends on stress level, and hence on the defect considered.
Micro and macro analysis of a thermonuclear fusion plant for reliability and performance
Authors: Chaharbaghi Kazem , Buende Rolf 
Published: July 2007

AbstractThe Next European Torus (NET) must be operated with appropriate reliability and availability levels if it is to attain its targets. A basic simulation model, the principles and potentials of which had been previously demonstrated, has been considerably extended to provide a more accurate representation of the operations of NET and to facilitate its study under various operating and reliability considerations. The latest simulation model of NET incorporates the physics phase as well as the technology phase. It encompasses complex features such as time and event dependent failure rates and independent failures. For ease of manipulating the uncertainties associated with the reliability data, the model has been furnished with the normal, exponential, lognormal and Weibull distribution modules. The level of subsystem breakdown is easily adjustable to match the needs of the design that is growing in detail. A goal‐seeking procedure has been developed for use in conjunction with the simulation model. The application of this procedure culminates in operating and reliability strategies which will enable NET to achieve its intended targets. This paper describes the operating and reliability features of NET together with the ways in which they have been captured by the NET simulation model. The underlying philosophy and application of the goal seeking procedure is also demonstrated through illustrative results.
Fault curves—A novel drift‐fault diagnosing method for condition monitoring
Authors: Drake P. R. , Williams J. H. 
Published: July 2007

AbstractA drift‐fault diagnosing method is presented based on fault curves fitted to changes in a single characteristic of a system performance curve such as the peak of the step response. The method consists of fitting a fault curve, for each potential fault in the system, to samples of the characteristic produced under different levels of the faults. Unknown faults are then diagnosed, irrespective of severity, by seeing which fault curve is closest to the characteristic produced by the system under test. It is argued that this method is very appropriate for diagnosing faults detected by condition monitoring systems since these will be drift faults, and because the method can be applied to normal operational signals without the need to inject special test signals.
Evolution of VLSI reliability engineering
Authors: Crook D. L. 
Published: July 2007

AbstractProjection indicates that by the turn of the century microcomputer chips will have 100 million transistors and failure rates of less than 10 FIT. Traditional accelerated product life tests and wafer level reliability measurement techniques being developed at present will have severe limitations in resolving the 10 FIT failure rate of complex VLSI circuits. This paper discusses these limitations along with the change in direction that the reliability engineering and manufacturing community will have to take over the next decade to meet the challenge of continuously decreasing failure rate goals.
Reliability of multi‐channel Ga1−xAlxas high electron mobility transistor (HEMT) integrated circuits
Authors: Christou A. , Tseng Wen 
Published: July 2007

AbstractThe reliability of HEMT ICs has been analysed when they are treated as weakly coupled dual channel systems. The separation distance between the two‐dimensional electron gas channels is the critical parameter which affects reliability. The introduction of deep traps at 0·65 eV has been shown to occur during accelerated life tests. In addition, the HEMT dual channel IC reliability results tend to follow the enhancement mode degradation statistics. All testing was carried out at 12 GHz and at channel temperatures between 130°C and 250°C.
Convenient construction of t‐tests for quality evaluation
Authors: Nachlas Joel A. 
Published: July 2007

AbstractAn available numerical approximation to the Student's t distribution is described and its use in the construction of t‐tests is presented. The result is a convenient and accurate computer based approach to the selection of the sample size and critical value to be used in a t‐test. Computational logic for implementation of the approach is provided and the method is illustrated by an example.
Control chart design a review of standard practice
Authors: Porter Leslie J. , Caulcutt Roland 
Published: July 2007

AbstractMany standard texts on SPC offer simple procedures for setting up control charts. Although the procedures work well in some situations, there are many instances where the procedures do not produce useful charts. The failure to sustain SPC initiatives is often due to an over simplistic model of process variability.This paper examines the widely used procedures for setting up control charts and illustrates how these may fail when the process variability has certain characteristics. A more robust alternative procedure is examined in some detail. This involves taking a closer look at process variability and incorporating this with control chart design.
Testing for reliability improvement or deterioration in repairable systems
Authors: de La Mare R. F. 
Published: July 2007

AbstractThis paper reviews the derivation and application of the reverse arrangement test which is used to assess whether a system has improved or deteriorated in a reliability sense. Because the well‐known and published table of statistics for this test is erroneous, the prime objective of this paper is to provide the correct statistical table. A secondary aim, however, is to demonstrate how this table can be applied when there is a paucity of failure data for each individual system and to show how a more meaningful reliability assessment can be obtained by pooling results, from the reverse arrangement test, for several systems.
Floating gate memories reliability
Authors: Crisenza G. , Clementi C. , Ghidini G. , Tosi M. 
Published: July 2007

AbstractBesides conventional IC failure mechanisms, the floating gate (FG) device reliability is affected by data retention, characteristic of non‐volatile memories, and endurance, typical of electrically erasable arrays.The subjects of this work are EPROM and flash EEPROM, the leading and most promising devices among the FG non‐volatile memories.The degradation mechanisms observed in programming and erasing steps are investigated. EPROM data retention is associated with intrinsic and defect related charge loss with both electronic and ionic processes involved. Experimental results are presented.The reliability problems associated with repeated write/erase cycles are introduced, and their effects on EEPROM endurance discussed.Finally, a fishbone diagram for data retention is proposed. The complexity of technology and the cell scaling down with increasing chip size impose lower failure rate goals and reliability becomes integrated within the manufacturing process.
Emission microscopy
Authors: Kölzer J. , Dallmann A. , Deboy G. , Otto J. , Weinmann D. 
Published: July 2007

AbstractEmission microscopy has now become established as an effective technique in terms of reliability physics of industrial semiconductors. This convenient method allows chip verification and failure analysis to be carried out in many applications. Besides this, emission microscopy provides a technique for use in device engineering and the optimization of test structures. The key to using this technique to permit a more sophisticated quantitative analysis lies in an unique assignment of the light emission to the defect mechanism. Since the corresponding phenomena are numerous and their details have to be clarified before this technique can be used routinely in a quantitative rather than qualitative approach, fundamental investigations were carried out on the basis of test structures. The applicability of quantitative aspects of emission microscopy in practice, i.e. exemplified by some relevant case studies, has further been discussed in this paper.
Transiently triggered latch‐up in cmos twin‐tub and epitaxial technologies
Authors: Pavan Paolo , Caprara Paolo , Stucchi Michele , Zanoni Enrico 
Published: July 2007

AbstractWe present in this work an analysis of transiently triggered latch‐up in test‐structures fabricated using a twin‐tub process implemented on two different substrates: a p‐type and a p p+ epitaxial one. Steady‐state electrical characterization confirmed the well‐known increased latch‐up resistance of epitaxial structures with respect to standard ones. In this paper it is shown that, depending on the chosen electrical configuration, when latch‐up is transiently triggered, epitaxial structures may have dynamic triggering currents lower than twin‐tub ones. The influence of some layout variables on turn‐on threshold voltage has been investigated for all samples.
A structural reliability model for composite materials
Authors: Corvi Andrea , Vangi Dario 
Published: July 2007

AbstractThis work is a part of a project aimed at developing a model and procedure to evaluate the structural reliability of a laminate whose laminae properties are statistically known. The inputs consist of the laminae's elastic properties (deterministic in that they are not as closely related to manufacturing technology) and the derived allowable strengths (aleatoric variables), as well as the sequence (number, orientation, position) of the laminae in the laminate. The output, the laminate's structural reliability, allows determination of the laminate's collapse process, with the most probable lamina failure sequence.
An application of a bathtub failure model to imperfectly repaired systems data
Authors: Love C. E. , Guo R. 
Published: July 2007

AbstractIn this paper we use an exponential power distribution to develop a bathtub failure model for repairable systems. These results are compared with those using the more familiar Weibull distribution. The analysis is extended to three types of repair scenarios: good‐as‐new repairs (in which the repair following a failure completely refreshes the failure intensity), bad‐as‐old repairs (in which the repair has no effect on the failure intensity) and imperfect repairs (in which the failure intensity is only partially reset). We apply this analysis to hydro‐electric turbine data and find that an exponential power distribution produces a well‐defined bathtub failure model when used with an imperfect repair assumption. We furthermore find that this bathtub model produces an improved fit over the equivalent Weibull model.
Electromigration in ALCu interconnections with W‐plug contacts
Authors: Ferlazzo L. , Reimbold G. , Gonchond J. P. , Heitzmann M. , Demolliens O. , Lormand G. 
Published: July 2007

AbstractTungsten is widely investigated for contact and via filling to improve planarization and step coverage. Although many electromigration data are available on multilayered structures, very few studies have been carried out on W‐plug structures and mainly concern the vias. This paper investigates the electromigration performance of W‐plug contacts and underlines the main failure modes. A comparison is made with classical contacts and W‐plug vias, pointing out a new failure mode.
Autoclave tests of 64 K and 256 K SRAMs
Authors: Polman H. L. A. , Fokkens K. 
Published: July 2007

AbstractResults are presented of HAST tests of 64 K and 256 K SRAMs of 10 manufacturers at three temperature/humidity conditions. Failed memory cells are clustered in four different, manufacturer dependent, ways. A relation between the type of defect cluster and weaknesses in the manufacturing process is presented.
Tolerance design: Choosing optimal tolerance specifications in the design of machined parts
Authors: Jeang Angus 
Published: July 2007

AbstractThis paper provides a general approach for determining tolerances for machined parts which minimizes the combined machining cost and quality cost. We derive a mathematical model which takes into consideration both machining cost and quality cost, which depend on tolerance specifications and the distribution of the machined part dimension produced by a chosen machining process. The model represents the quality cost with a loss function and represents the machining cost with a fitted curve based on some original data. The distribution of the machined part characteristic is taken to be either normal or triangular, depending on model assumptions. By applying this model, designers can determine the tolerance which provides the minimum expected total cost.
A stochastic approach to consequence tree analysis
Authors: Schäbe Hendrik 
Published: July 2007

AbstractIn this paper a stochastic approach to consequence tree analysis is considered. A consequence tree is a set of events logically combined by OR and AND connections that occur in sequence, some being prerequisites for others. Consequence trees are applicable to failure propagation in plants. Facilitating paths and inhibiting cuts are defined and considered. The distribution of the time the system needs to reach a certain top event is obtained. Probability weights are defined that can be used to obtain the weakest link in the consequence tree.
Testing of the quality of solder joints through the analysis of their thermal behaviour with an interferometric laser probe
Authors: Claeys W. , Quintard V. , Dilhaire S. , Lewis D. , Danto Y. 
Published: July 2007

AbstractWe present an optical contactless method for testing the quality of solder joints in surface mounted components by measuring their thermal dynamic behaviour. We detect surface normal displacements induced by Joule heating with a high resolution interferometnc laser probe. This probing method, based upon a homodyne Michelson interferometer, is an interesting tool for investigating the mechanisms of heat deposition and flow inside electronic devices. It allows the precise time evolution of the surface normal displacement to be measured (the laser probe has subnanometric resolution).This new approach of thermal behaviour laser testing is based upon the analysis of the diffusion of heat produced by the Joule effect in the structure (lead, solder and copper strip) from short current pulses and will influence heat diffusion. Solder joint failures (intermetallics, hidden voids, etc. ) behave as a thermal barrier. The optical test consists of measuring the dynamics of the solder joint expansion, and the variations from a standard response (good quality solder joints) will reveal defects. Important variations have been observed in solder joints that have undergone thermal cycling ageing tests.We have also investigated the thermal response of joints on IMS (insulated metallic substrate) and epoxy substrates. They show a very different time response.
SPC with correlated observations for the chemical and process industries
Authors: Mastrangelo Christina M. , Montgomery Douglas C. 
Published: July 2007

AbstractIn the use of statistical control charts, violating the basic assumption of independent or uncorrelated data results in a chart that exhibits poor statistical performance, resulting in an increased number of false alarms. Autocorrelated data requires modifications to traditional control chart techniques. A method based on the exponentially weighted moving average that uses variable control limits is presented. Using simulation, we explore the shift detection properties of this moving centre‐line technique and will show how the detection capability of the procedure can be enhanced using supplemental tracking signal tests. Guidelines and conditions for use are also presented.