bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffractional Nuclear Processes Involving Composite Particles
Authors: Sitenko A. G. 
Published: July 2007

AbstractThe diffractional picture of nuclear processes at high energies involving composite particles is given. The solution of the Lippmann‐Schwinger equation for the problem on scattering in the scattering center systems is considered in the high‐energy approximation. The general formulas for the cross section of different diffractional processes with particle transmission are obtained. The effects of multiple scattering and their mutual compensation are discussed. The applicability conditions of the diffractional approach are discussed. The diffractional processes during the interaction of high‐energy deuterons with nuclei are considered in detail. Without the assumption of deuteron size smallness compared to nuclear size, the cross sections of different diffractional processes are calculated with nuclear boundary diffusion taken into account. The nonmonotonic dependence of the diffractional disintegration cross section for deuterons on the mass number is shown due to the influence of nuclear boundary diffusion. The role of the diffractional and the Coulomb mechanisms of interaction depending on the nuclear mass number is discussed. The calculated dependences are compared with experimental data. The interference during the multiple scattering and its relationship with the diffractional structure of the angular scattering during the scattering on the composite systems are considered. The comparison the between diffractional approximation and different variations of the impulse approximation is made.
Variational Matrix Padé Approximants in Two Body Scattering
Authors: Turchetti G. 
Published: July 2007

AbstractThe convergence and bounding properties of the variational matrix Padé approximants are investigated for non relativistic two body interactions.Selecting L – 1 discrete values qi, i = 1, …, L – 1 and the physical momentum q0 the off shell scattering amplitudes are L X L matrices.The [N/N] Padé approximants to the Born series of these matrices are the variational solution of the Schwinger principle and the corresponding physical amplitude has variational properties in the off shell momenta. For positive interactions the best approximants to the phase shift is an absolute minimum on the qi and monotonic convergence to the exact result for N → ∞ or L → ∞ ca be proved.Similar properties are shown for the bound states using the Ritz variational principle.The required mathematical background is extensively worked out, the extensions to non positive, singular and long range potentials are considered and some numerical examples are presented.
On the Quantization of Hydrodynamics
Authors: Kupsch J. , Rühl W. 
Published: July 2007

AbstractQuantization of hydrodynamics can be attempted by representation theory of the canonical field algebra or of an observable algebra. The canonical formalism of classical hydrodynamics is presented. It uses four scalar potentials and a four parameter non‐compact gauge Lie group. It is proved that any representation of the canonical field algebra of irrotational hydrodynamics is incompatible with the positivity of the mass density. The observable algebra of mass and current densities generates the flow group which possesses unitary irreducible representations that are compatible with positivity of the mass density. A method is described based on the additional assumption of mass conservation and time reversal invariance, that allows to derive a Hamiltonian from the representation. As illustrative example the method is applied to a canonical quantized model. No known representation of the flow group, however, can be interpreted as a hydrodynamic system.
Failure mode and effects analysis in the U.K. motor industry: A state‐of‐the‐art study
Authors: Dale B. G. , Shaw P. 
Published: July 2007

AbstractThis paper reports the main findings of a questionnaire survey on the use of failure mode and effects analysis (FMEA) in the United Kingdom motor industry. Survey data were obtained from 78 organizations. Among the main findings are: the majority of suppliers only started to use FMEA because it was a contractual requirement of their customer; however, a number of them are now seeking to make more use of the technique to facilitate their process of quality improvement; FMEA is treated by the majority of organizations as a team activity; engineers still view FMEA as a hard slog; more use should be made of computerized aids to reduce the effort in preparing and updating the FMEA; and the main difficulties encountered in the use of FMEA are related to time constraints, poor organizational understanding of the importance of FMEA, inadequate training and lack of management commitment. It is also pointed out that organizations are not satisfied with the current training courses on FMEA.
Investigation and characterization of a control scheme for multivariate quality control
Authors: Chua Meng‐Koon , Montgomery Douglas C. 
Published: July 2007

AbstractA new scheme for multivariate statistical quality control is investigated and characterized. The control scheme consists of three steps and it will identify any out‐of‐control samples, select the subset of variables that are out of control, and diagnose the out‐of‐control variables. A new control variable selection algorithm, the backward selection algorithm, and a new control variable diagnosis method, the hyperplane methods, are proposed. It is shown by simulation that the control scheme is useful in cases where the process variables are correlated and where they are uncorrelated.
Fault and cause diagnosis of casting defects: A case study
Authors: Sweeting F. B. J. , Thorpe W. R. , Pettitt A. N. 
Published: July 2007

AbstractThe product selected for detailed study was a cored grey iron disc, cast in a five cavity mould, subject to rejection at a highly variable rate. The behaviour of process variables in the sub‐systems of green sand, core making, metal pouring and metallurgical composition was analysed to detect any statistically significant correlations with the incidence of blisters, which was the predominant cause of rejection.To supplement the recorded data and to separate causal factors from correlations, a series of direct experimental trials was conducted to trace a faulty casting to the cavity, mould box, pouring conditions, green sand, cores and metallurgical composition pertaining at the time of actual production.From a progressively accumulated database of some 100 hours of the specific product runs, built up over several months, the production variables and responses were analysed using regression, ANOVA, correlation and factorial experimentation techniques. Three major interventions involving a change in bentonite supply and two modifications to the runner system were accompanied by a reduction of some 60 per cent in the mean level of blister rejects with an improved dispersion.
Failures in thin metal film resistors—A case history
Authors: Cain J. F. , Hart L. , McLean J. R. 
Published: July 2007

AbstractThis paper presents a case study that was initaated by excessive monitor failures occurring during a simulated early‐life test. Statistical analysis of the failure data suggested that there should be no longterm resistor failure problem. Large increases in resistance of some metal film resistors led to many of the monitor failures. Corrosion of the resistive film by residual chlorine for a particular resistor vendor's cleaning process was responsible. The results led to process changes to reduce the contamination and the reliability testing of the ‘new’ product revealed that the process changes were successful. A statistical designed experiment indicated that the ‘old’ resistors were not all degraded in the same manner. As a result of this experiment, the failures were attributed to poor process controls.
Reliability improvement via taguchi's robust design
Authors: Hamada Michael 
Published: July 2007

AbstractTaguchi's robust design strategy, whose aim is to make processes and products insensitive to factors which are hard or impossible to control (termed noise factors), is an important paradigm for improving products and processes. We present an overview of the strategy and tactics for robust design and demonstrate its usefulness for reliability improvement. Two important components of robust design are a criterion for assessing the effect of the noise factors and experimentation according to specialized experimental plans. Recent criticism of Taguchi's criterion and his analysis of its estimates has led to an alternative approach of modelling the response directly. We give additional reasons for using this response‐model approach in the context of reliability improvement. Using the model for the response, appropriate criteria for assessing the effect of the noise factors can then be evaluated. We consider an actual experiment and reanalyse its data to illustrate these ideas and method.
A new approach to statistically modelling the time dependent oxide breakdown
Authors: Vollertsen R.‐P. 
Published: July 2007

AbstractFor dielectric lifetime predictions, both, the characteristic lifetime of the distribution and its slope are important. Taking this into account, it is pointed out that the intrinsic breakdown time (a constant of the 1/E model) depends on the degradation behaviour of the weak spot under stress, which is represented by the failure percentage. A modified 1/E model is proposed. It considers the observed change of the slope of lifetime distributions taken at different electric fields. The modified model is in good accordance with available data. Furthermore, it includes the behaviour of the slope as predicted by the E and the 1/E models as special cases.
Reliability issues of offset drain transistors after different modes of electrical stress
Authors: Papadas C. , Mortini P. , Monsérié C. , Ghibaudo G. , Pananakakis G. 
Published: July 2007

AbstractThe reliability issues of offset drain transistors (ODTs) after different modes of static electrical stress (high voltage uniform gate stress, high voltage drain stress and hot carrier stress) are presented. Besides, the evolution of the macroscopic electrical parameters of these devices after high voltage uniform gate stress are attributed quantitatively to the evolution of the bulk gate oxide trapping characteristics and the variation of the Si/SiO2 interface state charge.
A general approach for testing the process capability index
Authors: Hoffman Lorrie L. 
Published: July 2007

AbstractThis paper presents a generalized approach to the problem of testing with the process capability index Cĉp. It allows for testing at any α‐level and any sample size. For small sample sizes n < 30, n odd, tables are included with αs incremented by 0.025, which are generated by a computer program. This program is written in BASIC and appears in an Appendix. For different α levels (say α = 0·1) the program can be used to generate the appropriate value to use in determining the critical values. For larger sample sizes an approximation method is supplied. Additionally, the method to derive an associated operating characteristic curve is examined.
Consideration of maintenance objectives in the design and development of software
Authors: Keene Karen C. , Keene Samuel J. 
Published: July 2007

AbstractFactors are addressed that affect the total cost of developing, deploying and supporting software systems. The experiences are drawn from a large computerized facility incorporating over half a million lines of application code. The operational and support activities dominate the cost considerations over program life.Techniques are presented in this paper to ensure early design considerations of these operational and support activities and to reduce their cost. Thus, the focus is the life cycle cost factors of the system software.
Hardware reliability assurance and field experience in a telecom environment
Authors: Hallberg Ö. , Eriksson B. , Francis R. , Hjortendal R. , Lindberg L.‐I. , Sävström B. 
Published: July 2007

AbstractThis paper gives an overview of some methods and procedures used to assure product reliability within Ericsson Telecom AB. The main focus in this paper is on hardware (HW) reliability at board and component level. The evolution of customer–vendor relations over the years is addressed. Some new concepts in complex component reliability assurance are described. Experience from field service is summarized.This information is open and may be subject to change at any time.
Local‐area network reliability models
Authors: Spragins John 
Published: July 2007

AbstractThis paper describes analyses of reliabilities of local area networks (LANs) designed according to the most common IEEE 802 standards: the token ring architecture (IEEE 802.5, basically the IBM token ring architecture), carrier sense multiple access/collision detection (CSMA/CD) bus architecture (IEEE 802.3, basically the Ethernet architecture) and token bus architecture (IEEE 802.4, the recommended LAN architecture for the manufacturing atomation protocol, MAP). Each of these architectures is assumed to be implemented using electrical conductors; newer architectures using fibre optics (such as FDDI) are currently being studied.The primary reliability parameter studied is average source‐destination availability. The models are based on information in the standards plus implementation details, using more implementation details than previous reliability models. Approximate analyses, which reflect all architecture details that appear to be pertinent to availability, have been developed, rather than exact analyses which ignore fine details. One conclusion is that details neglected in previous models have major effects on, and may be the most important factors determining, source–destination availability. At present, no measured values for the relevant parameters are obtainable, however, so all of our computations are based on arbitrary ‘guesstimates’ of these parameter values.A few other conclusions can be reached. Since major components of the bus networks (CSMA/CD and token bus) are similar, reliabilities of these networks are also similar, with differences determined primarily by differences in parameters. Adequate data to describe these differences were not obtainable, so our example computations for the two bus networks yield essentially the same results. Although its use of an active communications medium, instead of the passive bus used by the other architectures, may decrease reliability of the token ring, the token ring architecture gives more flexibility in bypassing or recovering from error situations. In some situations this could make the token ring the most reliable LAN, but ‘reasonable’ choices of parameter values could make any of the LANs most reliable. If many stations are inactive, however, any reliability advantage for token rings would be eliminated by even a small probability that inactive stations are not successfully bypassed
Real‐time empirical bayes manufacturing process monitoring for censored data
Authors: Feltz Carol J. , Sturm George W. 
Published: July 2007

AbstractBecause of the current work in manufacturing electronics which links high‐speed test sets to host computers, it is now possible to collect and analyse measurements seconds after a product is tested. However, some of the actual measurements may often not be collected. This paper describes a technique to monitor right‐censored, left‐censored or both right‐ and left‐censored manufacturing data. Also, the technique is applicable to ‘interval’ censored data; data that is censored when it occurs in an interval, with uncensored observations above and below the interval. This ‘interval’ censoring can occur when automatic test equipment cannot transmit data and test at the same time. To increase production volume through the test area, measurements are often collected only when a test fails.The method described is designed to monitor a manufacturing process in real‐time with the goal of identifying process changes as they occur. An empirical Bayes model of the process response parameters is developed for the situation when censoring is present. Estimates for the model are developed, a strategy for implementing the model is given and an example is presented which illustrates its use to monitor a process.
An exploratory study of a neural network approach for reliability data analysis
Authors: Liu Ming C. , Kuo Way , Sastri Tep 
Published: July 2007

AbstractThe results of this paper show that neural networks could be a very promising tool for reliability data analysis. Identifying the underlying distribution of a set of failure data and estimating its distribution parameters are necessary in reliability engineering studies. In general, either a chi‐square or a non‐parametric goodness‐of‐fit test is used in the distribution identification process which includes the pattern interpretation of the failure data histograms. However, those procedures can guarantee neither an accurate distribution identification nor a robust parameter estimation when small data samples are available. Basically, the graphical approach of distribution fitting is a pattern recognition problem and parameter estimation is a classification problem where neural networks have been proved to be a suitable tool. This paper presents an exploratory study of a neural network approach, validated by simulated experiments, for analysing small‐sample reliability data. A counter‐propagation network is used in classifying normal, uniform, exponential and Weibull distributions. A back‐propagation network is used in the parameter estimation of a two‐parameter Weibull distribution.
A method for the calculation of the softerror rate of sub‐μm dynamic logic cmos circuits
Authors: Juhnke T. , Bringmann M.‐P. , Klar H. 
Published: July 2007

AbstractAs a prerequisite for predicting the soft‐error rate (SER) of CMOS circuits with dynamic registers a method to calculate the SER is presented which takes into account charge collection by drift and diffusion. It has been found that besides collection due to drift, the noise charge collected by diffusion has to be considered to accurately predict the SER of dynamic CMOS circuits. Calculated results are compared to device simulations and SER measurements.
ESD protection elements during hbm stress tests—further numerical and experimental results
Authors: Russ Christian , Gieser Horst , Verhaege Koen 
Published: July 2007

AbstractCorrelation problems for HBM‐ESD testing result from the complex interaction between device and tester. The HBM stresses of different well‐characterized testers1.2 are applied to protection elements. By means of circuit simulations and in situ measurements, snapback and second breakdown during HBM are investigated. For fast transient events, a new transmission line approach of the tester improves the correlation between experiment and simulation.
Fracture mechanical characterization of IC‐device interfaces
Authors: Burger K. 
Published: July 2007

AbstractTo characterize the bond‐strength or adhesion of the different interfaces in plastic encapsulated ICs a fracture‐mechanical test method has been used. For this four‐point‐bend test a preparation method has been developed to get the four‐point‐bend test samples out of the moulded IC devices.The measurement of the adhesion along the main phase boundaries of plastic encapsulated devices before and after stress‐tests (HAST, pressure‐cooker, solder dips, temperature cycles) was done also to characterize the change in bond‐strength during those tests.A mechanical model is presented which helps to describe the PC‐specific corrosion phenomena as well as failures resulting from temperature cycle tests.
in situ failure detection in thick film multilayer systems
Authors: Manca J. , de Schepper L. , de Ceuninck W. , D'Olieslaeger M. , Stals L. M. 
Published: July 2007

AbstractBy means of in situ e.m.f.‐measurements, leakage current measurements and impedance spectroscopy, it has been possible for the first time to detect spontaneous and forced blistering in thick film multilayers during formation at high temperatures. Also the occurrence of high temperature shorts in Ag‐dielectric‐Ag multilayers under DC‐bias was detectable.
Total quality control for a surface mount technology process for the manufacture of printed circuit board assemblies
Authors: Chan Ling‐Yau , Law Lawrence Wing‐Tung 
Published: July 2007

AbstractSurface mount technology is used widely nowadays in the manufacture of printed circuit board assemblies in the electronics industry. The occurrence of defective products when this technology is used is mostly caused by technological problems, but sometimes it is also caused by management problems or human errors. When technological problems are being tackled, human interactions will always be involved. This is because the quality of a product is related to the quality of the material, the design of the product and the manufacturing process, and as tasks are subdivided, problems occurring in production cannot be solved completely by the sole effort of a single individual. Hence improvement of product quality involes man, machine, and material. This article explains how quality problems arising from surface mount technology are tackled by team effort in an organization via the implementation of a process‐oriented total quality control system.
Development of 3‐D shape measurement system using fiber grating
Authors: Nakazawa Kazuo , Nakajima Masato , Kobayashi Hirosi 
Published: July 2007

AbstractThere is an increasing demand in industry and medicine for the noncontact measurement of the shape of a 3‐D object. Various studies are being made to develop highly accurate and simple means of such measurements. When a laser light is incident to the fiber grating in the vertical direction, a square spot array is produced. When the array is projected on a 3‐D object with a general shape, the array is distorted. By using the distortion as the data for the processing, the 3‐D shape can be measured strictly. This paper reports on the 3‐D shape measurement using an optical fiber grating. No particular application is considered in the design of the system. The projector of the spot array can be constructed with a lightweight and small size, and it is suitable as a built‐in device for the endoscopy, or a visual device to be installed directly on the industrial robot arm.
Cooperative integration of multiple stereo matching algorithms
Authors: Watanabe Masaki , Ohta Yuichi 
Published: July 2007

AbstractThis paper describes a method in which three kinds of stereo matching methods based on different image features are integrated by a cooperative processing to realize a matching search system applicable to a wide range of objects. In other words, the point‐based matching using correlation, the interval‐based matching using edges and the segment‐based matching using connected edges are combined. The module for dedicated execution of each algorithm is provided, and the modules execute the matching search in parallel. Whenever necessary, the partial result of the processing is exchanged to realize a complementary cooperation.Each module continues the processing for the part which can be processed without being assisted by other modules. Then, considering each local area of the image, the best‐suited algorithm is selected and applied automatically according to the situation. Each module evaluates the extent of confidence of its own processing, and the reliability score is attached when the result of processing is exchanged. The module receiving the data appropriately considers the received data into its own processing, according to the confidence. The disparity image generation module integrates the results of three matchings according to the extent of confidence. The method is applied to several stereo images, and the usefulness of the proposed method is demonstrated.