Detecting process mean shift in the presence of autocorrelation: a neural-network based monitoring scheme

The main purpose of this paper is twofold: (1) to present a neural-network based methodology for monitoring process shift in the presence of autocorrelation; and (2) to demonstrate the power, the effectiveness, and the adaptability of this approach. The proposed neural network uses the effective and efficient extended delta-bar-delta learning rule and can be trained with the powerful back-propagation algorithm. The comparative study on AR(1) processes shows that the performance of this neural-network based monitoring scheme is superior to that of SCC, X, EWMA, EWMAST and ARMAST control charts in most instances. Moreover, the network output can also provide information about the shift magnitude. The study of run length distributions suggests that further improvement on designing such neural networks is possible. The adaptability of the neural-network approach is demonstrated through the flexible design of the training data set. To further improve run length properties under various shift magnitudes, alternative control heuristics are proposed.     

Using the method of conservative scalars for the calculation of thermal radiation of turbulent diffusion flame

Data on laser probing of laboratory flames are used to quantitatively estimate the contribution made by turbulent fluctuations of thermodynamic parameters to thermal radiation of hydrogen diffusion flame. The coefficients in the equation of radiation transfer are averaged directly by samplings of instantaneous values of temperature and concentration; this helps eliminate errors associated with the use of model distribution functions. The obtained results are used to verify the approximate method for the calculation of thermal radiation of flame, which is based on the assumptions of thermochemical equilibrium of combustion and normal distribution of the coefficient of mixture.     

An approximate method for the calculation of heat and mass exchange between gas and a liquid film

Using integral relations between the velocity and enthalpy of gas, we develop an engineering method for the calculation of the local and average parameters of media and the heat and mass flux without using the empirical data about contact instruments.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 2, pp. 191–198, August, 1987.     

Extraction of text lines and text blocks on document images based on statistical modeling

In this article, we developed a Bayesian model to characterize text line and text block structures on document images using the text word bounding boxes. We posed the extraction problem as finding the text lines and text blocks that maximize the Bayesian probability of the text lines and text blocks given the text word bounding boxes. In particular, we derived the so-called probabilistic linear displacement model (PLDM) to model the text line structures from text word bounding boxes. We also developed an augmented PLDM model to characterize the text block structures from text line bounding boxes. By systematically gathering statistics from a large population of document images, we are able to validate our models through experiments and determine the proper model parameters. We designed and implemented an iterative algorithm that used these probabilistic models to extract the text lines and text blocks. The quantitative performances of the algorithm in terms of the rates of miss, false, correct, splitting, merging, and spurious detections of the text lines and text blocks are reported. © 1996 John Wiley & Sons, Inc.     

Stress intensity factor calculation based on the work of external forces

The external forces method is a numerical method for K calculation based on the finite element method. It uses the work of the external forces W for the calculation of the energy release rate and is particularly advantageous when that forces are applied far from the crack front. The method was applied to a corner crack geometry with the objective of studying its accuracy. Good results were obtained for a wide range of virtual crack displacements (0.03% < Δa/a < 6%) considering 4 values of W along with a polynomial regression of order 3. For that choice of parameters the inaccuracy of K is mainly due to FEM errors. A great sensitivity of K to FEM errors was observed, however accurate values of K were obtained, with errors lower than 2 percent. So, the use of the external forces method for the calculation of K is recommended, considering its simplicity and accuracy. This revised version was published online in July 2006 with corrections to the Cover Date.     

Model for heat exchange between a well-developed fluidized bed and a surface within the bed

A physical model for heat exchange between a fluidized bed and a surface in contact with it is proposed and discussed. The heat exchange is due to heat transfer by oscillating particles.     

The effect of document types and sizes on the scaling relationship between citations and co-authorship patterns in management journals

The aim of this paper is to explore the power-law relationship between citation-based performance (CBP) and co-authorship patterns for papers in management journals by analyzing its behavior according to the type of documents (articles and reviews) and the number of pages of documents. We analyzed 36,241 papers that received 239,172 citations. The scaling exponent of CBP for article papers was larger than for reviews. Citations to articles increased 2^1.67 or 3.18 times each time the number of article papers published in a year in management journals doubled. The citations to reviews increased 2^1.29 or 2.45 times each time the number of reviews published in a year in management journals doubled. The scaling exponent for the power-law relationship of citation-based performance according to number of pages of papers was 1.44 ± 0.05 for articles and 1.25 ± 0.05 for reviews. The citations to articles increased faster than citation to reviews. The scaling exponent for the power-law of citation-based performance to co-authored articles was higher than single-authored articles. For reviews the scaling exponent was the same for the relationship between citation based performance and the number of reviews. Citations increased faster in single authored reviews than co-authored reviews.     

Generalized method of pressure drop and tube length calculation with boiling and condensing refrigerants within the entire zone of saturation

A simple and universal method of pressure drop and horizontal tube length calculation with boiling and condensing refrigerants within the entire saturation zone ranging from critical point down to the lowest temperatures, is proposed. The method can be applied for the calculation ofevaporators and condensers operating in conventional and non-conventional refrigeration, air conditioning and heat pump system, as well as in similar cases. By introducing a two-phase flow factor, β, and a liquid/vapour gradient ratio, θ, the correlation given by Müller-Steinhagen and Heck can be rearranged to a siple dimensionless form which leads to a family of universal curves that enable any dry-saturated vapour flow gradient to be transformed into an actual two-phase flow gradient, or vice versa, at any temperature and liquid/vapour mixture quality within the entire saturation zone of refrigerants. Determination of θ is a key factor in the accuracy of the calculation. Appropriate correlations and diagrams for predicting τ are presented in terms of corresponding states principle. Some practical advice and numerical examples of evaporators and condensers calculation are given.     

Criteria and formulas for the calculation of the fluidization rate

An equation of motion is derived for individual particles in a fluidized bed of a monodisperse material in connection with the onset of fluidization. Dimensionless complexes have been derived on the basis of this equation and these are used to process the experimental data. A theoretical formula is derived.     

Microscopic calculation of the heat transfer between a granular structure and liquid3He

A recent formula for the heat transfer coefficient between ³He quasiparticles and phonons of a sintered metallic powder is evaluated using the phonon density of states of a microscopic model of a granular structure. The microscopic model describes a simple crystalline granular structure and contains extended modes only. When the dominant phonon wavelength is less than a typical grain size, possesses a low-temperature enhancement typical of a sintered metallic powder and over a limited range exhibits a linear variation with temperature.     

Approximate calculation of the concentration of elements in eutectic coatings based on iron

Translated from Fiziko-Khimicheskaya Mekhanika Materialov, No. 4, pp. 29–34, July–August, 1989.     

Numerical calculation of the temperature difference between the extremities of a thermoacoustic stack plate

When a plate is placed in a thermoacoustic resonator, one extremity of the plate heats up while the other cools down due to the thermoacoustic effect. In the present work the temperature difference between the extremities of the plate is calculated numerically. The computed temperature difference is compared to the one predicted by the linear theory. Some discrepancies are found even at low acoustic Mach numbers. These discrepancies can not be attributed to non-linear effects, rather they exist because of thermal effects. In particular the mean temperature in the fluid and in the plate are not equal. The discrepancies can be eliminated using corrective coefficients. Some deviations between the linear theory predictions and numerical results also occur at higher Mach numbers and are due to non-linearities, and especially temperature non-linearities that are generated in the vicinity of the plate.     

Analytic calculation of the interaction between a pulsed electromagnetic field and a two-electrode horn antenna

An analytic solution of a system of differential equations derived earlier is obtained. Expressions are given for the current in the load as a function of the orientation of Poynting's vector with respect to the axis of the antenna, and the trasfer, characteristic of the transducer.     

On computer-aided analytic element analysis and the similarities of tetrahedron elements

A complete analytical analysis of three-dimensional, quadratic displacement tetrahedron elements is presented. The results show that the element stiffness can readily be obtained from the much simpler stiffness matrix of the linear displacement element. Thus, the task of obtaining the matrix of the quadratic displacement element is, in effect, reduced to finding that of the linear displacement element. The analysis has been made possible only by using a symbolic manipulation language (PL/I–FORMAC) on a computer. A rather general program for computer-aided basic element analysis is presented. It seems that the extremely effective tool of symbolic manipulation has hardly been used until now in mechanics.     

Theoretical calculation of uncertainty region for spherical particles based on a picket fence,quasi-monodisperse particles

In order to confirm the reliability of particle size measurement technique and to prepare standard reference particles for calibrating particle size measurement devices, experimental and theoretical studies have been conducted about the uncertainty region of particle size measurement for the picket fence and quasi mono-disperse particles. The vertical and horizontal uncertainty regions based on Tschebyscheff theory are calculated to the picket fence distribution composed of two kinds of nearly mono-disperse particles. The uncertainty region increases around the intermediate particle diameters between the two kinds of particles.Because the original particle size distribution is nearly mono-disperse, the uncertainty regions around the minimum and maximum particle diameter are small compared to the intermediate particle diameters between the two kinds of particles.The uncertainty region in vertical and horizontal direction changes to decrease with the increase of sample size. For the picket fence distribution composed of two kinds of nearly mono-disperse particles, the sample size about more than 10,000 is necessary to obtain the reliable results in particle size counting process.