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Objective The objective of this research is to use historical crash data to evaluate the potential benefits of both high- and low-speed automatic emergency braking (AEB) with forward collision warning (FCW) systems. Methods Crash data from the NHTSA's NASS-General Estimates System (GES) and Fatality Analysis Reporting System (FARS) databases were categorized to classify crashes by the speed environment, as well as to identify cases where FCW systems would be applicable. Results Though only about 19% of reported crashes occur in environments with speeds greater than 45 mph, approximately 32% of all serious or fatal crashes occur in environments with speeds greater than 45 mph. The percentage of crashes where FCW systems would be relevant has remained remarkably constant, varying between about 21 and 26% from 2002 to 2015. In 2-vehicle fatal crashes where one rear-ends the other, the fatality rates are actually higher in the struck vehicle (33%) than the striking vehicle (26%). The disparity is even greater when considering size-class differences, such as when a light truck rear-ends a passenger car (15 vs. 42% fatality rates, respectively). Conclusions NHTSA and the Insurance Institute for Highway Safety (IIHS) proposed the Automatic Emergency Braking Initiative in 2015, which is intended to make AEB (also called crash-imminent braking) with FCW systems standard on nearly all new cars by September 2022. Twenty automakers representing 99% of the U.S. auto market voluntarily committed to the initiative. Though the commitment to safety is laudable, the AEB component of the agreement only covers low-speed AEB systems, with the test requirements set to 24 mph or optionally as low as 12 mph. The test requirements for the FCW component of the agreement include 2 tests that begin at 45 mph. Only 21% of relevant serious injury or fatal accidents occur in environments at speeds under 24 mph, whereas about 22% of serious or fatal crashes occur in environments with speeds greater than 45 mph. This means that the AEB with FCW systems as agreed upon will cover only 21% of serious or fatal crashes and will not cover 22% of serious or fatal crashes. Because these systems are protective not only for the occupants of the vehicle where they are installed but also other vehicles on the roads, the data indicate that these systems should be a standard feature on all cars for high-speed as well as low-speed environments for the greatest social benefit.

In the fall of 2007, the National Highway Transportation Safety Administration (NHTSA), an agency within the U.S. Department of Transportation, issued a proposal to change the safety standard for r...

Introduction Le test de Landis est un examen scintigraphique qui permet d’evaluer la permeabilite capillaire aux proteines. Il est utilise pour le diagnostic du syndrome de fuite capillaire idiopathique. La procedure consiste en l’injection intraveineuse d’albumine marquee au 99mTc puis a la realisation d’une scintigraphie dynamique sur les membres superieurs. Au cours de l’acquisition, un tensiometre est gonfle sur l’un des bras pour augmenter la pression capillaire et favoriser le passage extravasculaire de l’albumine en cas de permeabilite pathologique des vaisseaux. Le brassard est ensuite degonfle. En cas de syndrome de fuite capillaire, une asymetrie de fixation des deux bras est observee en raison de l’extravasation de l’albumine. Materiel et methode Nous rapportons le cas d’un patient de 78 ans traite par bortezomib pour un myelome multiple a IgG Kappa avec atteinte renale (tubulopathie myelomateuse) et atteinte osseuse (fracture vertebrale). Suite a l’administration du bortezomib, le patient presente des œdemes des 4 membres et des paupieres avec une dyspnee d’effort croissante. Le bilan realise ne retrouve pas de cause cardiaque, hepatique ou renale a ces œdemes. Le traitement par furosemide est peu efficace. Le syndrome de fuite capillaire est evoque mais le patient ne remplit pas tous les criteres clinicobiologiques pour poser ce diagnostic : il presente bien une prise de poids de 5 kg et une hypoalbuminemie (30 g/L), mais sans hypotension ou hemoconcentration (hematocrite a 36 %). Resultat Un test de Landis est realise et met en evidence a la fin de l’examen une asymetrie de fixation des avant-bras avec un index de retention calcule a 17 % (normale Discussion Le syndrome de fuite capillaire est une pathologie rare qui se caracterise par la survenue de crises œdemateuses. Il peut etre idiopathique ou secondaire. Parmi les causes secondaires, on retient les hemopathies malignes, les pathologies auto-immunes et certains traitements. Chez ce patient, une origine iatrogene a ete retenue en raison de la survenue des symptomes apres le debut du traitement (1 seul cas dans la litterature). L’absence de certains criteres clinicobiologiques pourrait s’expliquer par le caractere iatrogene et non idiopathique de la pathologie. Dans ces cas atypiques, le test de Landis se revele interessant pour aider les cliniciens a poser le diagnostic.

To ensure high yield in the manufacture of compact, small assemblies, the flatness of individual components is strictly toleranced and controlled. Twenty industrial flatness data sets from four separate processes and three different materials are examin..

The capability index CPU is recommended for quality features such a linearity, flatness, circularity, and cylindricity that exhibit a unilateral specification of USL. Using industrial data sets as illustrations, a Wald statistic is developed for testing..

This article relates to the investigation of innovative power distribution components based on microelectromechanical technologies integrated with advanced optimization methods to improve the performance of electric power distribution systems. A novel medium voltage class circuit breaker using two switching string assemblies has been designed and implemented in a laboratory prototype. The building block is a switching unit, which includes microelectromechanical switch shunted by a diode. Several switching units are connected in series to form the switching string, and several strings are connected in parallel to form the switching string assembly. A magnetic coil activates the switches. A circuit breaker is comprised of two switching string assemblies connected in series. One string interrupts the current in the positive half cycle, and the other interrupts current in the negative half cycle. The opening of the mechanical switches transfers the current to the diodes, without arcing. In this way, ...

When selecting a supplier or assessing process improvement, it is useful to compare capability indices for two different processes or the same process before and after adjustment. Using computer simulation, several methods for performing this comparison..

The hypothesis test associated with a variational data-assimilation algorithm is examined in detail. It can be shown that the test statistic, Ĵ, should have a distribution, where M is the number of scalar data assimilated, if the hypothesis regarding the model and data residuals is consistent with the true physical system. The skill of the Kolmogorov–Smirnov (KS) test in identifying whether the hypothesis used in the assimilation is ‘true’ (that is, the hypothesis correctly reflects the residuals in the model and the data) or not (that is, the hypothesis has either incorrect parameters in the covariance or an incorrect bias) is evaluated. It is shown that the KS test does indeed have some skill in identifying a false hypothesis. However, as one might expect, the skill is limited to cases where the particular component of the hypothesis that is incorrect has an impact on the test statistic and therefore on its distribution. Copyright © 2004 Royal Meteorological Society.

The vast majority of research on capability indices has assumed that the data consists of one large, representative sample. In practice, and in much of the quality control literature, process data are collected over time in subsamples representing rational subgroups. In this paper we examine the statistical behavior of two Cpm estimators based on this more realistic data structure. The estimators correspond to pooled and un-pooled variance estimators. The theoretical findings are applied to hypothesis testing and power calculations.The power functions of the tests based on the two estimators are used to determine the minimum number of subsamples needed to meet a threshold requirement that power exceeds 0.80. Extensive tables of the recommended number of subsamples are provided with comments on their usage Validerad; 2004; 20061013 (evan)

Under the assumption of normality, the distribution of estimators of a class of capability indices, containing the indices , , and , is derived when the process parameters are estimated from subsamples. The process mean is estimated using the grand average and the process variance is estimated using the pooled variance from subsamples collected over time for an in-control process. The derived theory is then applied to study the use of hypothesis testing to assess process capability. Numerical investigations are made to explore the effect of the size and number of subsamples on the efficiency of the hypothesis test for some indices in the studied class. The results for and indicate that, even when the total number of sampled observations remains constant, the power of the test decreases as the subsample size decreases. It is shown how the power of the test is dependent not only on the subsample size and the number of subsamples, but also on the relative location of the process mean from the target value. As part of this investigation, a simple form of the cumulative distribution function for the non-central -distribution is also provided. Copyright © 2003 John Wiley & Sons, Ltd.

The quality of a set of manufactured features with complex geometric dimensioning and tolerancing call-outs is discussed. Since measurements taken during the inspection of these manufactured features do not always conform to the usual normality assumpti..

We present statistical evidence that when students voluntarily write reflective “journal entry” essays on assigned reading, their performance on multiple-choice quizzes on the reading is improved compared to students who do not complete such essays. A Smirnov non-parametric test and a pair-wise comparison analysis were used to establish the validity of the hypotheses.

For many quality characteristics, such as circularity, cylindricity, straightness and flatness, positive skewness in the inspection data is the norm, and, in fact, is desirable. Summarizing the process performance using such data in conjunction with capability indices has recently received a considerable amount of attention, with new indices being proposed and compared for usefulness and accuracy. This paper is intended to contribute to this growing discussion, and to add a unique focus. In particular, this investigation concentrates on one form of a neoclassical index, the Cs index, originally proposed to be sensitive to skewness and to decrease in value as the skewness increased in the underlying distribution of the data. In other words, ‘skewness is badness’. Looking at this index from an altered perspective, the possibility that this index could serve a useful purpose in summarizing process performance for such non-normal processes by merely changing its interpretation or slightly changing its form is considered. Hence, actual data from circularity measurements are used to identify a relevant group of distributions, and then the accuracy of Cs is investigated along with its modified version for this group of distributions. In particular, this investigation includes several Rayleigh and gamma distributions for various sample sizes and reports on the bias of the proposed estimators. These findings indicate that such a modified index has some useful attributes in reflecting process performance, with respect to the percentage of non-conformance and the accuracy for relatively large samples. Copyright © 2001 John Wiley & Sons, Ltd.

The capability index, Cpm, sometimes called the Taguchi index, has the desirable characteristic of being sensitive to both dispersion and deviation of the process average from the engineering target. As a result, the proposed estimators of Cpm have a sampling distribution that is dependent on the non-central chi-square distribution. Hence, constructing confidence intervals, performing hypothesis testing or estimating sample size requirements necessitates manipulation of a rather complex functional expression, typically beyond the capabilities of practitioners who need readily available tools. Here, a simple graphical procedure is proposed and illustrated for obtaining exact confidence intervals for Cpm. The graphical procedure allows the user to simply enter the graph with an estimate of the index and a value of the non-centrality parameter for a given sample size to arrive at end-points of 90%, 95% or 99% one-sided or two-sided confidence intervals. Detailed tables are also provided to assist the user for a wider range of sample values and sample sizes. In addition, a procedure is also presented for determining the minimum sample size required for attaining a pre-specified level of accuracy of the Cpm. Extensive tables are provided for the user with a simple example illustrating the facility of the technique. Copyright © 2001 John Wiley & Sons, Ltd.

[This abstract is based on the author's abstract.] Process capability analysis often involves characterizing or assessing processes or products on the basis of more than one engineering specification or quality characteristic. When these variables a..

Quantitatively assessing quality and using this assessment for competitive benchmarking and diagnostics of manufactured part failure are very important for continuous improvement in modern manufacturing industries. Process capability analysis often entails characterizing or assessing process specification or quality characteristics. When these quality characteristics are related, the analysis should be based on a multivariate statistical technique. A current problem in multivariate quality control is that there is no consensus about a methodology for assessing capability. Thus, the critical first step in instituting a multivariate control scheme is not well defined. While numerous authors have recently proposed alternative definitions of multivariate capability indices, those methods may not be practical in some cases. In this research, a new process control variable, geometric distance (GD), for assessing or evaluating the quality of manufactured product is developed and investigated for reducing dimensionality. The theoretical distribution of the geometric distance is investigated and a suitable performance metric of the multivariate process data is proposed. Finally, some real data are used to demonstrate the capability of the proposed method.

The intent of setting a threshold value on Cp,Cpk or Cpm for a quality characteristic in a manufacturing process is to constrain the percentage oi nonconforming parts. One of the important assumptions to the implementation of such a threshold value is that the quality characteristic is normally distributed. The purpose of this article is to demonstrate, using an entropic framework, that given a threshold constraint on the numerical value of the population capability index, Cpm, the most general distribution for our process is, in fact, the normal distribution. Furthermore, this most general distribution, based solely on the principle of maximum entropy over a constrained region, can be found prior to data collected on the process. In addition, if the derived normal distribution is treated as a prior distribution, then using the Kullback-Leibler (direct) divergence criteria and sample mean and variance values, a posterior or updated distribution can be found. It turns out that this updated distribution is ...

Point estimates of the capability index Cpm are generated from sample observations from manufacturing processes and are used to make comparisons of processes. Decisions based on these quantities should necessarily include information about the variabili..

This paper addresses the theory and tools that promote rapid product and process development of machined products. A foundation of this approach is the application of a new definition of manufacturing features called resource-based free-form features. Using free-form features we demonstrate how cost, time and quality predictions, based on available equipment, are computed. We also introduce the concept of intelligently clustering alternative features to achieve better process alternatives. The approach presented herein is appropriate throughout the product design life-cycle as an aid to faster product realization by evaluating the parochial manufacturability of a completed design. In particular, this approach will provide the design team with cost, time and quality predictions, based on available equipment, that can be used to guide the design process. It also provides the manufacturing team with an approach to evaluating producibility and generating a production plan for a product model using available equipment in terms of cost, time and quality.

In the process of assessing the safety of the fuel-containment system of the 1973-1987 General Motors C/K truck, the National Highway Traffic Safety Administration and General Motors Corporation have written and submitted numerous documents to a public file between October 1992 and April 1993. Five substantial reports have been issued by the National Highway Traffic Safety Administration and General Motors Corporation describing data analysis of crashes recorded on state and federal databases. Both the National Highway Traffic Safety Administration and General Motors Corporation have used crash data, in some cases the same data, to examine the claim that a defect in the fuel system design of General Motors Corporation C/K trucks poses an unreasonable risk of death or injury. The comparative analysis presented in this paper demonstrates how crash databases and their summary statistics can be used to support opposed positions in a safety dispute. Understanding differences in the analysis is fundamental to obtaining an insight into the role of field crash data, including its relevance and shortcomings, in defect and recall investigations.

Process capability indices (PCIs) are used in industry to assess percentages of nonconforming parts. An underlying assumption is that the output process measurements are distributed as normal random variables. When normal distributions are assumed, but different distributions are present - such as skew, heavy-tailed, and short-tailed distributions - the percentages of nonconforming parts are significantly different than the computed PCIs indicate. Data arising from nonnormal distributions can sometimes be transformed to conform to the normality assumption and the PCI's computed for the transformed data. In this paper, the effect of the transformation on the estimate of nonconforming parts is examined for three examples of nonnormal distributions - gamma, lognormal, and Weibull. The results of this experimental analysis suggest that data transformation can be useful for estimating an interval for Cpk values and the number of nonconforming parts.

Background Idiopathic inflammatory myopathies (IIM) and eosinophilic fasciitis (EF) are defined as idiopathic inflammation of muscle or fascia. In patients clinically suspected of having those entities, Magnetic Resonance Imaging (MRI) is performed to assess muscle involvement, and 18F- Fluorodeoxyglucose Positron Emission Tomography (PET) to exclude a paraneoplastic origin of the symptoms. Objectives In this study, we aimed to compare the relative performance of MRI and PET in the detection of muscle and/or fascia inflammation. Methods This retrospective board – approved study included 18 patients suspected of MII (12) or EF (6) in which both MRI and an 18 F-FDG PET were available and performed within a interval ≤3 months, and in which no therapeutic changes occurred between the two exams. The mean interval between MR and PET was 7 days [range -62 (PET performed between MRI) to +91]. For each subject, muscular involvement was independently evaluated on MRI and PET in up to 17 possible predefined muscular groups, subdivided on 3 categories: upper limbs, lower limbs and trunk. A total of 220 corresponding muscular groups were analyzed. A group was considered abnormal on MR when a high signal was seen on fat saturated T2w images (either in muscle or fascia) and, on PET, when high uptake was present. The Kappa statistics between the two imaging modalities were calculated. Results MRI detected significantly more lesions than 18 F-FDG PET in the 3 categories (upper limbs, lower limbs and trunk) (p 18 F-FDG PET was 0.67 (95% confidence interval 0.57 to 0.77); it was 0.81 (CI 95 0.70–0.93), 0.50 (CI 95 0.31–0.68) and 0.65 (CI 95 0.34–0.97) for upper limbs, lower limbs and trunk, respectively. Conclusions MRI seems more accurate to detect inflammatory changes of muscle or fascia than 18FDG PET when myositis or fasciitis is clinically suspected. Disclosure of Interest None declared

Brown tumors are uncommon osteolytic lesions directly related to the increased osteoclastic activity due to hyperparathyroidism.A 37-year-old woman presented with hypercalcemia related to primary hyperparathyroidism. Multiple and bilateral maxillary osteolytic lesions showing intense fluorodesoxyglucose (FDG) uptake were noted in a positron emission tomography computed tomography (PET-CT). Diagnosis of maxillary brown tumors was discussed and confirmed by both orthopantomogram and magnetic resonance imaging. Left inferior parathyroid adenoma was detected by both cervical ultrasonography and parathyroid scintigraphy, and then surgically treated with consequent improvement of hyperparathyroidism.Our case emphasizes the necessity of a multidisciplinary diagnostic approach to optimize the interpretation of the available imaging, especially in unusual and unrecognized pathology as brown tumors.

Experimental design techniques were applied to the task of characterizing the inspection capability of the machine vision component of an automated laser hole-drilling and inspection system for gas turbine engine manufacturing. The system uses a laser t..

Back-propagation pattern recognizers (BPPR) are proposed to identify unnatural patterns exhibited on Shewhart control charts. These unnatural patterns, such as cycles and trends, can provide valuable information for real-time process control. In a computer-integrated manufacturing environment, the operator need not routinely monitor the control chart but, rather, can be alerted to patterns by a computer signal generated by the proposed algorithm. In this paper, an off-line analysis is performed to investigate the training and learning speed of these BPPRs on simulated X¯ data. The best configuration of the network is further tested to demonstrate the classification capability of the proposed BPPR.

The pattern recognition algorithm presented here is based on the perception that, as automated data collection becomes more widespread in manufacturing processes, the monitoring of control charts will be performed by computer-based algorithms. These algorithms will have to detect unnatural patterns to assist in the correction of assignable causes. The work currently being performed in addressing the application of pattern recognition to control charts is directed toward answering this need. In this paper, a control chart pattern recognition methodology based on the back-propagation algorithm, a neural computing theory, is presented. This classification algorithm, suitable for real-time statistical process control, evaluates observations routinely collected for control charting to determine whether a pattern, such as a trend or cycle, exists in the data. The foundation of the algorithm is based on the neural network concepts of constructing and training a network in the types of patterns to be detected. These concepts mimic the trained operator's ability to detect patterns. Here, the pattern recognizer is trained and tested with the consideration of Type I error (finding a pattern where none existed) as well as Type II error (failing to detect a known pattern). Performance measures sensitive to these types of errors are used to evaluate the algorithm's performance on an extensive series of simulated patterns of control chart data. This approach is promising because of its flexible training and high-speed computation.

Nous avons lu avec un tres grand interet l’article de Bailly et al. [1] qui ont rapporte leur experience sur l’irradiation du personnel de chirurgie gynecologique lors de la recherche du ganglion sentinelle en pathologie mammaire. Leur etude monocentrique et prospective a comporte des mesures dosimetriques sur le personnel medical et soignant. L’activite moyenne de Tc-colloides d’albumine injectee etait respectivement de 50,1 2,4 MBq et de 90,4 3,2 MBq le jour et la veille de la chirurgie. Les doses moyennes recues pour chaque intervention par le chirurgien, l’aide-operatoire et l’infirmiere de bloc ont ete respectivement de 5, 3,75 et 0 mSv pour l’exposition au corps entier et de 17,5, 15,6 et 16,2 mSv aux extremites. Les auteurs ont conclu que pour les chirurgiens de leur equipe, pratiquant moins de 30 procedures sentinelles par an, l’irradiation au corps entier et aux extremites de chacun d’entre eux etait inferieure aux seuils annuels reglementaires. Ces donnees suscitent quelques remarques. La reglementation francaise et europeenne issue des recommandations de la Commission internationale de protection radiologique (CIPR) fixe une limite annuelle en dose efficace (corps entier) pour le public a 1 mSv sur 12 mois consecutifs. En se fondant sur les resultats obtenus par les auteurs, cela correspond a une exposition pour un chirurgien pratiquant chaque annee 200 procedures sentinelles environ. Or, les indications de lymphadenectomie selective sentinelle ont progresse, celles-ci etant realisees en routine par de nombreuses equipes pour les cancers T1 et T2 [2], unifocaux ou a foyers multiples [3] et les carcinomes in situ etendus. Ce chiffre de 200 peut donc etre facilement atteint par un chirurgien specialise en senologie. Par ailleurs, alors meme que la lymphadenectomie selective sentinelle s’est largement developpee dans le monde entier a partir des annees 2000, les activites administrees par point d’injection restent tres controversees et varient, selon les equipes, entre 1,8 MBq et 370 MBq [4]. Les recommandations de la Society of Nuclear Medicine and Molecular Imaging (SNMMI) et de l’European Association of Nuclear Medecine (EANM) preconisent l’administration de 50 MBq si l’injection a lieu la veille de l’intervention [5]. En ce qui concerne l’activite injectee, seuls Van der Ent et al. [4] disent ameliorer leur sensibilite de detection par l’administration de fortes doses au site d’injection. Dans notre equipe, nous realisons des injections peri-areolaires de 15,5 0,7 MBq en moyenne 18 heures avant la chirurgie. Avec ces faibles doses, dans un essai clinique prospectif [6], nous avons pu montrer que l’identification des ganglions sentinelles etait possible pour 99 % des procedures (94 % des ganglions etant chauds et 65 % colores) et que ce protocole etait sur, aucune des 100 patientes de l’essai n’ayant presente de recidive axillaire apres 76 mois de suivi. Par ailleurs, une campagne de mesures dosimetriques au moyen de dosimetres thermoluminescents (TLD) etalonnes a 141 keV montre des niveaux d’expositions moyens par procedure de 4,7 2,6 mSv aux index du chirurgien et une exposition corps entier inferieure a 1 mSv (10 procedures). Ainsi, l’extrapolation des doses a l’annee pour 200 procedures et pour un seul chirurgien donne une dose aux extremites de 940 mSv, soit plus de 50 fois inferieure a la limite reglementaire du public pour les extremites (50 mSv/12 mois). Il est ainsi possible de reduire davantage l’exposition du personnel par procedure sans perdre en sensibilite de detection peroperatoire.

Boltzmann machines (BM), a type of neural networking algorithm, have been proven to be useful in pattern recognition. Patterns on quality control charts have long been recognized as providing useful information for correcting process performance problems. In computer-integrated manufacturing environments, where the control charts are monitored by computer algorithms, the potential for using pattern-recognition algorithms is considerable. The main purpose of this paper is to formulate a Boltzmann machine pattern recognizer (BMPR) and demonstrate its utility in control chart pattern recognition. It is not the intent of this paper to make comparisons between existing related algorithms. A factorial design of experiments was conducted to study the effects of numerous factors on the convergence behavior and performance of these BMPRs. These factors include the number of hidden nodes used in the network and the annealing schedule. Simulations indicate that the temperature level of the annealing schedule significantly affects the convergence behavior of the training process and that, to achieve a balanced performance of these BMPRs, a medium to high level of annealing temperatures is recommended. Numerical results for cyclical and stratification patterns illustrate that the classification capability of these BMPRs is quite powerful.

A comprehensive expert system design is presented for all problem-solving aspects of statistical process control. Issues concerning the integration of monitoring, interpreting, diagnosing, planning, and statistical consulting for statistical process control are addressed. All aspects of the expert system are discussed. In addition, a new similarity measure useful in a clustering approach to the knowledge organization is proposed. An example session is presented which diagnoses a cyclic pattern in a surface-finishing operation.

An improved neural network approach to produce short-term electric load forecasts is proposed. A strategy suitable for selecting the training cases for the neural network is presented. This strategy has the advantage of circumventing the problem of holidays and drastic changes in weather patterns, which make the most recent observations unlikely candidates for training the network. In addition, an improved neural network algorithm is proposed. This algorithm includes a combination of linear and nonlinear terms which map past load and temperature inputs to the load forecast output. The search strategy and algorithm demonstrate improved accuracy over other methods when tested using two years of utility data. In addition to reporting the summary statistics of average and standard deviation of absolute percentage error, an alternate method using a cumulative distribution plot for presenting load forecasting results is demonstrated. >

(2000). Measuring Process Capability, Process Capability Indices in Theory and Practice. Journal of Quality Technology: Vol. 32, No. 1, pp. 85-87.

[This abstract is based on the author's abstract.] Jet-turbine component manufacturing involves complex manufacturing operations. The manufacture of airfoil or blades and the subsequent profile inspection through coordinate measuring machines is es..

A hierarchical classification algorithm is applied to hourly temperature readings to divide the historical database into seasonal subsets. These subsets are used to statistically identify and fit a response function for each season. These functional models constitute a library of models useful to the power scheduler. For a particular day, the appropriate model is selected by performing discriminant analysis. This approach is illustrated using data from a summer peaking utility. This application demonstrates that an entire procedure for specifying forecasting models can be formed with currently available statistical software. Furthermore, the models can be implemented on a microcomputer spreadsheet. >

This paper contains an analytical method for the failure analysis of a matrix configuration of switches in series and parallel. The concept is to use lower voltage and current rating switches in series and parallel to attain the higher ratings needed in power engineering applications. The analysis is based on probability state transition. A discussion of voltage and current snubbing is given. Representative results are illustrated and applications are suggested.

In this paper we introduce a new approach and definition to manufacturing features which is useful for manufacturing evaluation and for generative operation planning. A manufacturing feature here is based on extraction of manufacturing feature primitives that correspond to faces of a solids model and the accessibility of a factory resident machine tool. These features are not based on form or templates. Extraction of a primitive includes calculation of the cutting path and operation parameters for that primitive, which in turn permits the calculation of machining cost and time. These primitives are grouped, or clustered, into manufacturing features based on an objective function, such as minimum-cost. A manufacturing feature is a logical grouping of manufacturing feature primitives that share a machine, setup, and cutting tool. This unique conceptualization of manufacturing features that does not rely on form features. With this approach many manufacturing feature interpretations are possible for a single model. The methodology is presented that provides a foundation for the development of clustering heuristic and operational planning.