Showing papers in "Journal of Research of the National Institute of Standards and Technology in 1994"
TL;DR: The inclusion rating method by statistics^ extreme values (IRMSE) using y/area of inclusions as the size parameter enables one to discriminate between super clean steels as mentioned in this paper.
Abstract: The inclusion rating method by statistics^ extreme values (IRMSE) using y/area of inclusions as the size parameter enables one to discriminate between current super-clean steels. Moreover, IRMSE enables one to predict the size {y/area-m,^ of maximum inclusions contained in domains larger than the inspection domain. The statistical di.'itribution of s/area^, can be used for the quality control of materials and for the prediction of a scatter band of fatigue strength. Practical procedures of inclusion rating and prediction of a scatter band of fatigue strength arc shown.
134 citations
TL;DR: In this article, the current state of scanning electron microscopy (SEM) metrology is reviewed in light of many of these recent improvements, including optical microscopy and scanning probe microscopy.
Abstract: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 During the manufacturing of presentday integrated circuits, certain measurements must be made of the submicrometer structures composing the device with a high degree of repeatability. Optical microscopy, scanning electron microscopy, and the various forms of scanning probe microscopies are major microscopical techniques used for this submicrometer metrology. New techniques applied to scanning electron microscopy have improved some of the limitations of this technique and time will permit even further improvements. This paper reviews the current state of scanning electron microscope (SEM) metrology in light of many of these recent improvements.
76 citations
TL;DR: The NIST sealed water calorimeter was used for a series of approximately 3700 measurements to investigate the so-called heat defect, that is, anomalous endothermic or exothermic effects caused by dissolved gases.
Abstract: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 The NIST sealed water calorimeter is intended for direct measurement of absorbed dose to water. This calorimeter was used for a series of approximately 3700 measurements to investigate the so-called heat defect, that is, anomalous endothermic or exothermic effects caused by dissolved gases. The three systems investigated were "high-purity" water saturated with N2, H2, and mixtures of H2/O2. The repeatability of the measurements of absorbed dose rates for the '*"Co teletherapy beam was studied with different water fillings and accumulated absorbed dose. Measurements with the H2/O2 system varied with accumulated absorbed dose. Based on the measurements and theoretical considerations, it appears that the H2saturated system is the best choice for eliminating the heat defect. Measurements with both the N2and H2-saturated systems are in good agreement with those determined with a graphite and graphite-water calorimeter (for which there is no heat defect).
70 citations
TL;DR: In this paper, the authors present a case study based on 10 years of hourly wind speed data collected at a U-K, site, elucidating the most successful procedure emerging from an extensive study of this data.
Abstract: University of Newcastle upon Tyne, Newcastle upon Tyne, U.K. Models for extremes of environmental processes have been studied extensively in recent years. The particular problems arising when attempting lo estimate return levels from sequences of measurements an the appropriate variables have been considered in some detail. In particular, the aspects of seasonal variation and short-range dependence have received a great deal of attention. In this paper we present a case study based on 10 years of hourly wind speed mea.
58 citations
TL;DR: In this article, the necessary and sufficient conditions for the extraction of the value distributions of multivariate exircme statistics are given by using dependence functions, and the joint asymrHolic dtsiribution of multi-scale statistics is also shown.
Abstract: Kobe University of Mercantile Marine, Kobe, Hyogo 658, Japan Some necessary and sufficient conditions itsr ilomains of aitraction of tnultivariaic CJitremc value distributions are shown by using dependence functions. The joint asymrHolic dtsiribution of multivariate exircme statistics is also shown.
51 citations
TL;DR: The beam addition method has been used for linearity measurement in the detector metrology program at the National Institute of Standards and Technology (NIST) as discussed by the authors, where the linearity of a silicon photodiode-amplifier detector system was determined to be within 0.054% (2 sigma) over nine decades of signal.
Abstract: The design and operation of Beamcon III, the latest linearity measurement instrument using the beam addition method in the detector metrology program at the National Institute of Standards and Technology, is described. The primary improvements in this instrument are the reduction of stray radiation to extremely low levels by using three well-baffled chambers, a larger dynamic range, and an additional source entrance port. A polynomial response function is determined from the data obtained by this instrument using a least-squares method. The linearity of a silicon photodiode-amplifier detector system was determined to be within 0.054% (2{sigma} estimate) over nine decades of signal.
45 citations
42 citations
TL;DR: In this paper, a multivariate extremal index is introduced which is shown to have properties analogous to its uni variate counterpart, and two examples of bivariate moving average sequences are presented for which the exiremai index is calculated in some special casc&.
Abstract: Colorado State University. Fort Collins, CO 80523 The exceedancc poim process apprfyjich of Hsing ct al. is exirnded to multivariale stationury sequences anj some weak convergence results are obtained. It is well known that under general mixing assuEtipliors, high level exceedanccs typically have a limiting Compoutid Poisson sinjcturc where muliiple evenli aie tauscd by the ciustcring ot exccedancesIn this (laper we explore
37 citations
TL;DR: In this paper, the maximum pit depth depending on the stirface area can be evaluated hy using the Gumbel distribution with the concept of return period, and a standardized procedure is proposed for estimating the minimum time for crack generation.
Abstract: Application of extreme value stati'iiics to corrosion is rcvieweJ. It is cmpha sized that the concept of corroiiion probability is important for a quanlitalivc evaluatioti Of corrosion failure and its prediction, especially for localized corrosion. Extreme value statistics is quite useful for assessing the maximum pit depth and/or the minimum time for crack generation. The maximum pit depth depending on the stirface area can be evaluated hy using the Gumbel distribution with the concept of return period. A standardized procedure i.? proposed for estimating the maximum pit depth. Examples of corrosion failure analysis using extreme value statistics, which were reported mainly in Japan, arc shown. Accumulated experiences suggest thai an appropriate classification of data based on the corroiiion mechanism is reijuircd iKfore applying extreme value analysis.
34 citations
33 citations
TL;DR: The Low Background Infrared Calibration Facility (LBIR) at the National Institute of Standards and Technology has been in operation for calibration measurements of the radiant power emitted from infrared radiation (IR) sources, such as cryogenic blaclcbodies, for more than 2 years as discussed by the authors.
Abstract: The Low Background Infrared Calibration Facility (LBIR) at the National Institute of Standards and Technology has been in operation for calibration measurements of ihe radiant power emitted fn>rn infrared radiation (IR) sources, such as cryogenic blaclcbodies, for more than 2 years. The IR sources arc sent to NIST by Customers from industiy, government, and university laborato^ii^s. An absolute ciyngenic radiometer is used as the standard detector to measure the total radiant power at its aperture. The low background is provided by a closed cycle helium refrigeration system that maintains the inner parts of Ihe calibration chamber at 20 K. The radiance temper* ature of the blackbody is deduced from the measured power and cottipared with the htackbody temperature sensor data. The calibration procedures and data analysts arc illustrated using the measurements of a typical blackbody. Key wonts; blackbody calibrations; cryogenic blackbodies; cTyogenic radiometer; electrical substiiuiion radknnetry, low background infrared radiation calibrations; radiomctiy.
TL;DR: In this paper, the effects of uncertainties in temperature on the expanded uncertainty of length of length measurements made away from the intemationat standard reference temperature of the International Temperature Scale of 1990 (rrS-W) were examined.
Abstract: National Institute of Standards and Technology, Gaithersburg. MD 20899-0001 This report examines the effects tt( uncertainties in temperature and cxicfficient of thennaJ expan.\\k>n on the expanded uncertainty of length (UmcrH sional measurements made away from the intemationat standard reference temperature of ^ \"C foi artifact standards and workpieces of various materials. Specific cases examined deal with: 1) uncertainties of thermal-expansion coefficients associated with values given in engineering references, standard reference data, standard reference tnatcriaIs and direct measurements^ and 2) ui]ccrtaiiilics of part temperature measurements associated with realaing the International Temperature Scale of 1990 (rrS-W) and detcnniiiing part temperatures relative to ITS-90 with the principal types of thertDonwtry and achievat^ levels of temperature controt.
TL;DR: In this article, a simple automated measuremeru system that uses a single, high accuracy, commercially available digital voltmeter (DVM) to compare the voltages developed across a 10 kil standard resistor and a quantized Hall resistor when the same current is passed through the two devices is determined.
Abstract: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 TVansporUible lO IcH standard rcstslors h<[ve become fairly widespread in industrial, university, and government standards laboralories because of iheir \tr*/ tempcralurc coefficieni of resistance, ease of iransportaIjon. and convenient value. The values of these resistors, however, tend to drift with lime, requiring jieriodic recalibration against an inv-iu^iant standard such as the quantized Hali resistance. The availability of a simple, inexpensive measuremeni system for calibrating 10 kft resistors against such an invariant standard would be of great benefit to primary standards taboratories. This paper describes a simple automated measuremeru system that uses a single, high accuracy, commercially available digital voltmeter (DVM) to compare the voltages developed across a 10 kil standard resistor and a quantized Hall resistor when the same current is passed through the two devices. From these measurements, the value of the 10 kQ standard resistor is determined. The sources of uncertainty in this system arc analyzed in detail and it is shown thai it is possible to perform calibraltons with lelative combined standard uncertainties less than lXl(r'(0.1 ppm).
TL;DR: Statistical methods relating to extreme value theory can be used to model and predict the statistical behaviour of extremes such as the largest pit, thinnest wall, maximum penetration or similar assessment of a corrosion phenomenon.
Abstract: In the oontcxi of corrosion engineering it is often natural to be eunccrned with extreme events. This is because, firstly, it is these cxiiemc events that often lead to failure and, secondly, it may only be poii^^ibie to measure the extremes, with much of the underlying measurements by their very nature unobservablc. Statistical methods relating to extreme value theory can be used to model and predict the statistical behaviour of extremes such as the largest pit, thinnest wall, maximum penetration or similar assessment of a corrosion phenomenon. These techniques can be applied to the single largest value, or to a given number of the largest values, measured over individual areas or coupons: ur to all values exceeding a given threshold. The data can be modeled to account for dependence on environmental conditions, surface area examined, and the duration of exposure or of experimentation. The application of a selection of these techniques is demonstrated on data from industry and from laboratory cxpeTimcnts.
TL;DR: In this paper, a technique using 16-bit digital-to-ana log conversion was developed for current control with a relative expanded uncertainty of about 1 part in 65536, corresponding to a spectral irradiance difference of approximately 0.006% for an FEL lamp at 655 nm.
Abstract: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 As radinmctric lamp ■ttandards improve, the need to set lamp current to specific values bccotncs more important. Commercially available power supplies typically provide 12 bit internal digiialto-analog logic which permits current control with a relative expanded uncertainty of about 1 part in 4096, corresponding to an expanded uncertiiinty of the current of about 2 mA at 8 A (in this paper, expimded uncertainties are given as 2 standard deviations). For an FEL-typc standard spectral irradiance lamp, this corresponds to a spectral irradiance difference of 0.12% at 6SS nm. We have developed a technique using 16 bit digital-to-ana log conversion which permits current control with a relative expanded unccrtaintj' of about 1 part in 65536, corresponding to an expanded uncertainty of the current of about 0.1 mA at 8 A. This corresponds to a spectral irradiance difference of approximately 0.006% for an FEL lamp at 655 nm. We describe the technique used to achieve this improvement and wc show data from a lamp demonstrating the effect of the improvement. Wc also describe the limitation provided by the uncertainty of the resistance of the current measuring shunt.
TL;DR: To illustrate the difficulty that The authors face in predicting cumulative pitting damage, a set of data that was collected in the laboratory is selected and the advantages and disadvantages of each approach are illustrated in order that the most reliable methods may be employed in future algorithms for predicting pittingdamage functions for engineering structures.
Abstract: Various attempts have been made (o develop models for predicting the development of damage in metals and alloys due to pitting corrosion. These muOcIs may be divided into two cliu.ses: the cmpirieiil approach which employ.s extreme value statistics, and the deterministic approach based on perceived mechanisms for nuclcation and growth of damage. More recently. Artificial Neural Networks (ANNs), a iioniletermlnistic t)'pc of model, has been developed lo describe the progression of damage due to pitting corrosion. Wc compare the three approaches above — Statistical, deterministic, and neural network!). Our goal i.s to Illustrate the advantages and disadvantages of each approach, in order that the most reliable methods may be employed in future algorithms for predicting pitting damage functions for engineering structures. To illustrate the difficulty that We face in predicting cumulative pitting damage, we selected a set of data that was collected in the laboratory. Wc compare and contrast the three approaches by reference to this data set.
TL;DR: In this paper, the instrumentation, measurement procedures and determination of uncertainty for SRM-484 and illustrates with data from issues 484e and 484f are presented. Butler et al.
Abstract: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 Standard Reference Material 484 is an artifact for calibrating the magnification scale of a Scanning Electron Microscope (SEM) within the range of 1000 X to 20000 X. Seven issues, SRM484, and SRM-484a to SRM-484f, have been certified between 1977 and 1992. This publication documents the instrumentation, measurement procedures and determination of uncertainty for SRM-484 and illustrates with data from issues 484e and 484f.
TL;DR: In this paper, the authors demonstrate quantization of the longitudinal voltage drop along the sample is a general feature of the quantum Hall effect in the breakdown regime, which occurs when electrons are excited to higher Landau levels and then return to the original level.
Abstract: Quantized breakdown voltage states are observed in a second, wide, highquality GaAs/AlGaAs sample made from another wafer, demonstrating that quantization of the longitudinal voltage drop along the sample is a general feature of the quantum Hall effect in the breakdown regime. The voltage states are interpreted in a simple energy conservation model as occurring when electrons are excited to higher Landau levels and then return to the original level. A spectroscopic study of these dissipative voltage states reveals how well they are quantized. The statistical variations of the quantized voltages increase linearly with quantum number.
TL;DR: In this article, a trivariate extreme value distribution was derived from the logistic model of the multivariatc extreme value distributions and the construction of its corresponding probability distribution and density function was described.
Abstract: A trivariate extreme value diiitribution has been derived from the logistic model fur the multivariatc extreme value distribution. The construction of its corresponding probability distribution and density function is described. ID order to obtain the parameters of such a trivariate distribution, a generalized maximum likelihood estimation procedure is described to allow for the cases of samples with different record lengths. Furthermore the reliability of (he estimated parameters of the trivariate extreme value distribution is mca sured through the use of relative information ratios. A region in Northern Mexico with six gauging stations has been selected to apply the trivariate model. Results produced by the proposed model have been compared with those obtained by general extreme value (GEV) distribution functions. Key word.i; distribution functions; distribution models; flood frequency analysis; method of maximum likelihood; trivariate extreme value distributions.
TL;DR: Gdttingen et al. as mentioned in this paper introduced convergence results for sampling from a distribution having asymptotically independent radial and spherical components and regularly varying tail of the radial component.
Abstract: University of Gottingen Gdttingen, Gennany Wc introduce muUivariaie extremes in the direction of a given cone. Convergence results for the number of the it ih cxlreraes are obtainecj for sampling from a distribution having asymptotically independent radial and spherical components and regularly varying tail of the radial component.
TL;DR: This chapter discusses the development of the Classical Model for Probabilistic Number Theory and its application in Engineering Applications and its applications in Science and Technology.
Abstract: Preface. Recollections of E.J. Gumbel C. Eisenhart. I: Engineering Applications E. Castillo, H.M. Taylor, A.E. Mansour, P.K. Sen. II: Univariate Statistical Inference L. de Haan, J. Pickands III, J. Gross, A. Heckert, J. Lechner, E. Simiu, F. Marohn. III: Computer Programs, Computations R.-D. Reiss, S. Hassmann, M. Thomas, M. Sibuya, J. Galambos, N. Macri. IV: Multivariate Theory and Applications H.A. David, R.L. Smith, J. Tawn, S. Coles. V: Nonclassical Models J. Husler, E. Pancheva. VI: Point Processes and Extremes S.I. Resnick, R. Roy, M. Falk, R.-D. Reiss, H.N. Nagaraja. VII: Continuous Time M.R. Leadbetter, S.M. Berman. VIII: Special Topics for the Classical Model M.I. Gomes, D.M. Mason, T.S. Turova, R.J.G. Wilms. IX: Probabilistic Number Theory J.-M. De Koninck. X: Astronomy S.P. Bhavsar. XI: Business L. de Haan, D.W. Jansen, K. Koedijk, C.G. de Vries, J. Beirlant, J.L. Teugels, P. Vynckier. Subject Index.
TL;DR: In this paper, the most common problems associated with the determination of design wave heights are discussed and two common methods used In fitting wave data and some of the stability or inconsistency prcAlems associated with commonly used distributions are given.
Abstract: This paper discusses the most common problems associated with the determination of design wave heights. It analyzes two common methods used In fitting wave data and shows some of the stability or inconsistency prcAlems associated with commonly used distributions. Some methods to obtain confidence intervals, detecting of outliers and treatment of missing data are given.
TL;DR: In this paper, a new theory and methodology for the forecasting of extreme and/or record values in an exchangeable.sequence of variable variables is developed, based on the Hill tail index estimator for long-tailed di.
Abstract: This arlicic develops new theory and methodology for the forecasting of extreme and/or record values in an exchangeable .sequence of randum variables. The Hill tail index estimator for long-tailed di.strihutions is modiricd so as to be appropriate for prediction of
TL;DR: The authors examines the potential connections between extreme value statistics, problems in aerosol science, and a recent technique of solving ill-posed inversion problems, called EVE {Extreme Value ^limatiun}.
Abstract: This work examines the potential connections between extreme value statistics, problems in aerosol science, and a recent technique of solving ill-posed inversion problems, called EVE {Extreme Value ^limatiun). EVE estimates functional^ of the unknown solution by searching the extreme (maximum and minimum) values of that functional within a set of acceptable solutions. The statistics of occurrence of extreme values in real life were not considered when this method was developed. The results of this technique are more con servative than those of the other methods used to solve the prt^lem of aerosol size distribution estimation like non-linear least squares, expectationmaximization, regularization, etc. The utilization of the customary methods of deconvolution may lead to an underestimation of the possibility of occurrence of extreme values in real life- It is suggested that consideration of extreme value statistics might aid in better defining the limits to be placed on the physically acceptable solutions in the EVE deconvolution. Other problems could also benefit from the application of extreme value statistics including the estimation of the second highest value of measured airtiorne particle mass in the context of the ambient air quality standard for particulatc matter less than 10 |i.m and the determination of the Maximally Exposed Individual as required under the 1990 revisions to the Clean Air Act.
TL;DR: In this paper, the authors proposed a stochastic method for evaluating the magnitude of future earthquakes taking account of nonstationarity in earthquake occurrence, and found that the distributions of maximum ground acceleration fit the type III extreme value distributions and the expected values of those distributions depend on the strain energy accumulation significantly.
Abstract: Civil Engineering Department, Tohoku University, Aoba Aramaki, Sendai 980, Japan The object of this paper is to propose a stochastic method for evalualinf the magnitude of future earthquakes taking account of nonstationarity in earthquake occurrence. For this purpose, the strain energy accumulation in the focal region was estimated by nieans of the earthquake data of the past 100 years in Japan. Furthermore, the distributions of maximum ground acceleration were derived by means of the attenuation law. As a result, we found that the distributions of maximum ground acceleration fit the type III extreme value distributions and that the expected values of those distributions depend on the strain energy accumulation significantly. Finally, it is pointed out that the nonstationariiy in earthquake occurrence should be taken into consideration in order to evaluate the earthquake toad in design.
TL;DR: In this article, it is suggested that in many environmental and other contexts the severity of an extreme event might usefully be represented as the sum of the excesses of a measured variable over a high threshold.
Abstract: It is suggested here thai in many environmental and other contexts the severity of an extreme event might usefully be represented liy tlie sum of the excesses of a measured variable over a high threshold. Tl>e general form of the limiting distributiiins iif UKU for a wide class of models has been derived by Andetsor and Dancy, and has suggested methods for the sl;itistical analysis of data concerning extreme severity. This work is reviewed here, and some extensions to the distribu!ion;il theoiy are presented. An application of the methods to atmoiipheric ozone levels, which calls for the extension of the approach to take account of covariate information h reported.
TL;DR: In this paper, the authors reported new isotope abundance and relative atomic mass (atomic weight) values for two previously described silicon reference materials using a well-known method with an improved isotope-ratio mass spectrometer.
Abstract: New isotope abundance and relative atomic mass (atomic weight) values — with low, hitherto unattained uncertainty—are reported for two previously described silicon reference materials using a well-known method with an improved isotope-ratio mass spectrometer. These new values are directly traceable to the SI, more specifically to the unit for amount of substance, the mole, and independent of the SI unit of mass and of the Avogadro constant. Besides the residual mass-spectrometric uncertainties, these new values depend in effect only on a recently published direct comparison of the cyclotron frequency in a Penning trap of ^"Si'* with that of
TL;DR: In this paper, the optical system used by JCandpal, Vaishya, and Joshi in their work on coherence-induced spectral shifts is analyzed theoretically and an approximate form for the cross-spectral density in the second aiy source plane is obtained, and it is shown that the corresponding complex degree of spectral coherence in this plane is wavelength dependent.
Abstract: The optical system used by JCandpal, Vaishya, and Joshi in their cxpcrimcnis on coherence-induced spectral shifts is analyzed theoretically. An approximate form for the cross-spectral density in the second aiy source plane is obtained, and it is shown that, contrary to the assertions of Kandpal, Vaishya, and Joshi, the corresponding complex degree of spectral coherence in this plane is wavelength dependent. After making some assumptions about the behavior of the interference filter used in the system, an approximate form for the spectrum of the light on-axis in the observation plane is obtained. It is shown that the peak wavelengths of (his spectrum do not agree with those reported by Kandpal, Vaishya, and Joshi. Possible reasons for this disagreement arc discus.sed.