Showing papers by "Indian Institute of Technology Kharagpur published in 1976"
TL;DR: In this paper, an analysis of three-stage series production systems with all possible combinations of exponential and deterministic stages was carried out and it was shown that optimum unbalancing results from a superposition of these two effects can be obtained.
Abstract: ‘ Bowl phenomenon ’ refers to the increase in production rate obtained by unbalancing a series production system such that the service time increases progressively on either side of the central stage(s). While such a result is valid for production systems with otherwise identical stages, earlier studies have suggested that a different effect may come into play when the stages of the system differ in their variability. In the simplest case of n two-stage system, production rate could be improved by shifting a part of the work load from the more variable stage to the less variable one. From an analysis of three-stage systems with all possible combinations of exponential and deterministic stages, it is shown in the present paper that optimum unbalancing results from a superposition of these two effects. This loads in some cases to a large improvement in the production rate. For the large differences in coefficients of variation considered in this paper, the ‘ variability imbalance ’ clearly plays a ...
82 citations
53 citations
TL;DR: In this article, the authors extend the capability of the class of methods to cover time-lag systems, which is illustrated with reference to one of the methods that employs Poisson moment functionals.
Abstract: The methods of system identification due to Shinbrot, Perdreauville and Goodson, Fairman and Shen, and Diamessis belong to a class of techniques based on the idea that a linear operation on system equations leads to a set of simultaneous equations solvable for the unknown parameters. These methods have so far been able to treat problems of linear time invariant, time-varying, nonlinear, and distributed parameter systems without lags. This short paper extends the capability of the class of methods to cover time-lag systems. The extension is illustrated with reference to one of the methods that employs Poisson moment functionals. Illustrative examples include linear time invariant, time-varying, and non-linear systems each with a lag.
46 citations
TL;DR: A method for the analysis of the effects of subjective and objective tolerances in networks and systems is presented and networks representing humanistic systems may be analysed using this method.
Abstract: A method for the analysis of the effects of subjective and objective tolerances in networks and systems is presented in this paper. The imprecision of the components is represented using fuzzy sets and then the value of the desired attribute is computed. The resulting attribute is also fuzzy and is obtained in the form of a fuzzy set. This fuzzy set contains the extremal and other values of the desired attribute along with their grades of membership. Thus, apart from getting the extremel values, we get the overall picture of the attribute. Since this method is directly applicable for the analysis of subjective tolerances, networks representing humanistic systems may be analysed using this method.
43 citations
TL;DR: In this article, thermal activation energy (E) and frequency factor (s) of the TL peaks calculated assuming first-order kinetics were calculated under the assumption that the frequency factor is different.
Abstract: Thermoluminescence (TL) is used to study the bleaching kinetics of F centers and the formation of Z1 centers in X-irradiated Ca-doped NaCl crystals. An additional TL peak is observed in this system after F-bleaching of the X-irradiated samples which is attributed to the thermal annealing of Z1 centers. The present result shows that bleaching of F centers takes place in two stages, a fast early stage followed by a slow later stage. However the formation kinetics of Z1 centers is different in the sense that initially the concentration of this center increases and then it decreases for prolonged F-bleaching. Thermal activation energy (E) and frequency factor (s) of the TL peaks calculated assuming first order kinetics show that though the frequency factor (s) is different, the thermal activation energy (E) is practically the same for all the TL peaks. Since ENDOR studies have shown that Z1 center can be described as a strongly perturbed F center the present results are explained in terms of thermal annealing of the F center electron trapped in different local environments.
Thermolumineszenz (TL) wird zur Untersuchung der Entfarbungskinetik von F-Zentren und der Bildung von Z1-Zentren in rontgenbestrahlten, Ca-dotierten NaCl-Kristallen benutzt. Ein zusatzliches TL-Maximum wird in diesem System nach F-Bleichung der rontgenbestrahlten Proben beobachtet, was der thermischen Ausheilung von Z1-Zentren zugeschrieben wird. Die vorgelegten Ergebnisse zeigen, das die Bleichung von F-Zentren in zwei Stufen erfolgt, einer fruhen schnellen Stufe, auf die eine spatere langsame folgt. Jedoch ist die Bildungskinetik der Z1-Zentren in dem Sinne unter-schiedlich, das anfanglich die Konzentration dieser Zentren zunimmt und dann bei andauernder F-Bleichung abnimmt. Die Werte der thermischen Aktivierungsenergie (E) und des Frequenzfaktors (s) der TL-Maxima, die unter der Annahme von Kinetik erster Ordnung berechnet wurden, zeigen, das, obwohl der Frequenzfaktor (s) unterschiedlich ist, die thermische Aktivierungsenergie (E) praktisch fur alle TL-Maxima dieselbe ist. Da ENDOR-Untersuchungen gezeigt haben, das die Z1-Zentren als stark gestorte F-Zentren angesehen werden konnen, werden die vorgelegten Ergebnisse mit thermischer Ausheilung von F-Zentren-Elektronen erklart, die in verschiedener lokaler Umgebung angehaftet sind.
41 citations
TL;DR: A method for the analysis of fuzzy systems using the concept of fuzzy sets is proposed, which enables us to represent quantitatively the sum (or product) of fuzzy variables like large and small, and the convolution of fuzzy sequences.
Abstract: The behaviour of the humanistic systems is too complex or too ill-defined to be analysed using definitive mathematics. In this paper we propose a method for the analysis of such systems using the concept of fuzzy sets. The methods for the manipulation of fuzzy variables are considered. These methods enable us to represent quantitatively the sum (or product) of fuzzy variables like large and small, and the convolution of fuzzy sequences. Since, while working with fuzzy variables, the data may become enormous, a technique for the data reduction is proposed. Using these techniques for the manipulation of fuzzy variables we are in a position to analyse fuzzy systems.
34 citations
TL;DR: In this article, the authors present a critical appraisal of the Protodyakonov index and conclude that the accuracy of the index as determined by the standard procedure is susceptible to certain defects.
34 citations
TL;DR: In this paper, the mean production rate of a series production system with identical Erlang stations is obtained by solving an integral equation formulated by Muth, which is much more feasible computationally for realistic systems with large Erlang parameters (k).
Abstract: The mean production rate of a series production system with identical Erlang stations is obtained by solving an integral equation formulated by Muth. In this method, one needs to solvE only k simultaneous equations rathor than the k(k + 1) (k + 3) equations generated by the ‘ method of stages ’ approach. As such, it is much more feasible computationally for realistic systems with large Erlang parameters (k). Results are reported for values of k up to 25.
27 citations
TL;DR: In this paper, the self-excited oscillation of a flexible, square section, slender, cantilever beam in a uniform, smooth wind stream was examined experimentally and theoretically.
25 citations
TL;DR: In this paper, the authors investigated flow in the Ekman layer of a conducting liquid past an infinite porous plate when the liquid is permeated by a transverse magnetic field and the Hall effects are taken into account, and found that asymptotic solution exists both in the presence of suction or blowing at the plate.
25 citations
TL;DR: In this article, the authors considered the Hall effects in a parallel plate channel with a transverse magnetic field and found that the primary flow shows incipient flow reversal at the upper plate for an increase in temperature along that plate.
TL;DR: In this paper, the two-dimensional boundary value problems of elastic half-spaces were solved using Somigliana's method and the solutions were compared with those derived from dislocation considerations.
Abstract: In this paper Somigliana's method has been utilized to solve the two-dimensional boundary value problems of elastic half-spaces. We have considered traction and displacement problem, shear problem, contact and crack problems and the solutions, thus derived, have been compared with those derived from dislocation considerations.
TL;DR: The preparation and characterization of quadricovalent cationic complexes of silver with biguanides and N′-amidinoisoureas have been described in this article.
TL;DR: In this paper, the problem of free and forced convective heat transfer of micropolar fluid in an annulus of two vertical pipes has been studied by applying Runge-Kutta-Merson method.
TL;DR: A method for machine recognition of hand-printed Devnagri numerals is described and the experimental results using computer are given.
Abstract: A method for machine recognition of hand-printed Devnagri numerals is described. The experimental results using computer are given.
TL;DR: A method of designing sequences with specified autocorrelation and cross-correlation properties is presented, based on power residue classification of a prime or a prime power, by first finding periodic sequences with acceptable correlation sidelobes and then testing these for aperiodic correlation.
Abstract: A method of designing sequences with specified autocorrelation and cross-correlation properties is presented in this paper. This is based on power residue classification of a prime or a prime power and consists of first finding periodic sequences with acceptable correlation sidelobes and then testing these for aperiodic correlation. Signals considered include binary, polyphase, and frequency-time coded sequences. Computer results for some short length sequences are also given.
TL;DR: In this paper, a set of equations of motion governing the bending and extensional displacements of a pre-twisted sandwich beam of rectangular cross-section are derived by using Hamilton's principle.
TL;DR: In this paper, a class of exact solutions to the source-free Brans-Dicke field equations is obtained which reduces to the Majumdar-Papapetrou class of solutions when the Brans Dicke scalar $\ensuremath{\varphi}=\mathrm{constant}".
Abstract: A class of exact solutions to the source-free Brans-Dicke Maxwell field equations is obtained which reduces to the Majumdar-Papapetrou class of solutions when the Brans-Dicke scalar $\ensuremath{\varphi}=\mathrm{constant}$. It has been observed that these solutions are important from the viewpoint of verifying Penrose's suggestion which states that the black holes in the Brans-Dicke theory are identical to those of Einstein's theory.
TL;DR: Based on the Diakoptic Equation, an algorithm is developed for block diagonalizing and solving any given set of linear simultaneous equations and is then applied to block diagonalize and solve the Jacobian matrix and hence the load flow problem.
Abstract: Based on the Diakoptic Equation, an algorithm is developed for block diagonalizing and solving any given set of linear simultaneous equations. This algorithm is then applied to block diagonalize and solve the Jacobian matrix and hence the load flow problem. The algorithm is perfectly general and can be appliedto any set of linear simultaneous equations, symmetrical or asymmetrical and hence can be applied to other fields as well. Applied to the load flow problem, it requires to consider a few more additional right hand side vectors to the Jacobian, and further an inter-subdivision matrix is to be formed and solved. No matrix inversion is required in this method and hence sparsity can be exploited to the maximum extent. Practical steps are given, so that the algorithm can be implimented by others.
01 Jan 1976
TL;DR: In this paper, the authors highlight the significant developments to date in the field of polymerization of nitrogen vinyl monomers by halogens and halogen-containing electron transfer agents with relevant reference to earlier work in these fields.
Abstract: The polymerization of nitrogen-substituted vinyl monomers by halogens and their compounds has been the subject of active research over the last 12 years. Several interesting features including, in particular, the development of the concepts of charge transfer polymerization [1, 2] have resulted from such studies. This article is intended to highlight the significant developments to date in the field of polymerization of nitrogen vinyl monomers by halogens and halogen-containing electron transfer agents with relevant reference to earlier work in these fields [1, 3]. In addition, the controversial developments in polymerization of these monomers by hydrogen halides and other organic halides will also be discussed. However, the general features of polymerization of these monomers by metal halides, recently reviewed by Biswas and Chakravorty [4], will not be included in the discussion.
TL;DR: In this article, the X-ray induced optical absorption (additional optical absorption) spectrum of Al2O3 exhibits absorption bands at 225 and 400 nm, which are attributed to the presence of F-centres and O− ions.
Abstract: Optical absorption and thermoluminescence measurements are made on Al2O3 and ruby (Al2O3 doped with 0.03 and 2 mol% chromium) single crystals irradiated with X-rays at room temperature. The X-ray induced optical absorption (additional optical absorption) spectrum of Al2O3 exhibits absorption bands at 225 and 400 nm. The X-ray induced optical absorption spectrum of Al2O3:Cr (0.03 mol %) exhibits absorption bands at 230, 295, 400, and 465 nm. X-ray irradiation is found to have no influence on the optical absorption of Al2O3;Cr (2 mol%). Irradiated Al2O3 shows thermoluminescence (TL) glow peaks at 160, 180, 235, 290, and 340°C. Chromium doping is found to affect the TL pattern as well as the TL light output of Al2O3 considerably. Al2O3:Cr (0.03 mol%) exhibits an intense TL glow peak at 325°C with a shoulder around 310°C, and a low intensity high temperature peak around 390°C. Al2O3:Cr (2 mol%) shows very feeble thermoluminescence. The occurrence of the absorption bands at 225 and 400 nm in the additional absorption spectrum of Al2O3 is ascribed to the presence of F-centres and O− ions. An attempt has been made to understand the coloration and luminescence process taking place in Al2O3 and ruby in the light of the experimentally observed results.
Messungen der optischen Absorption und Thermolumineszenz werden an Al2O3- und Rubin-(Al2O3 dotiert mit 0,03 und 2 Mol% Chrom) Einkristallen nach Rontgenbestrahlung bei Zimmertemperatur durchgefuhrt. Das rontgenstrahlen-induzierte optische Absorptionsspektrum (zusatzliche optische Absorption) von Al2C3 zeigt Absorptionsbanden bei 225 und 400 nm. Das rontgenstrahlen-induzierte optische Absorptionsspektrum von Al2O3:Cr (0,03 Mol%) zeigt Absorptionsbanden bei 230; 295; 400 und 465 nm. Es wird gefunden, das Rontgenbestrahlung keinen Einflus auf die optische Absorption von Al2O3:Cr (2 Mol%) hat. Bestrahltes Al2O3 zeigt Thermolumineszenz-Glowmaxima bei 160; 180; 235; 290 und 340°C. Es wird gefunden, das Chromdotierung sowohl die TL-Kurven als auch die TL-Lichtausbeute von Al2O3 betrachtlich beeinflust. Al2O3:Cr (0,03 Mol%) zeigt ein intensives TL-Glowmaximum bei 325°C mit einer Schulter bei etwa 310°C und ein schwaches Hochtemperaturmaximum bei etwa 390°C. Al2O3: Cr (2 Mol%) zeigt sehr schwache Thermolumineszenz. Das Auftreten von Absorptionsbanden bei 225 und 400 nm im zusatzlichen Absorptionsspektrum von Al2O3 wird der Anwesenheit von F-Zentren und O−-Ionen zugeschrieben. Es wird ein Versuch unternommen, den Verfarbungs- und Lumineszenzprozes, der in Al2O3 und Rubin stattfindet, im Lichte der experimentall beobachteten Ergebnisse zu diskutieren.
TL;DR: In this paper, the hole conductivity data of growing AgI film on silver both for the thicker (5500 to 30 000 A) and thinner (<6000 A) ranges at about room temperature.
Abstract: This work reports the hole conductivity data of growing AgI film on silver both for the thicker (5500 to 30 000 A) and thinner (<6000 A) ranges at about room temperature. Hole conductivity has been estimated through tarnishing studies of silver in iodine atmosphere and estimation has been based on the fundamental equation of Wagner relating the rate constant and the conductivity of the film. It is revealed that the thinner films show a higher hole conductivity than that of the thicker films under similar temperature and iodine pressure.
TL;DR: In this paper, an exact solution for the fully developed convective flow of an electrically conducting fluid between two vertical thermally and the walls, under a transverse magnetic field, was found.
21 Mar 1976
TL;DR: In this article, the Galerkin method is applied to solve the coupled differential equations of motion for an aerofoil cross-section blade with asymmetry about only one principal axis.
Abstract: This paper presents analytical and experimental investigations to determine the coupled bending-torsion natural frequencies of cantilever blades mounted on a rotating disk. Galerkin method is applied to solve the coupled differential equations of motion for an aerofoil cross-section blade with asymmetry about only one principal axis. The blade is considered to be mounted with the axis of symmetry in the plane of disk rotation. Results obtained are presented in non-dimensional form, showing the effects of rotation, disk radius, and asymmetry on the lowest three-coupled bending and lowest three-coupled torsion frequencies. An experimental rig is designed and fabricated to test rotating blades using piezoelectric crystals to excite the blades and also to pick up the response. The theoretical results are shown to be in good agreement with experimental observations.Copyright © 1976 by ASME
TL;DR: In this article, four salts of a new series of the type LH[VOF 3 (H 2 O)] (where L = pyridine,2,6,-lutidine, 2,2′-bipyridyl and 1,10-phenanthroline) have been isolated by crystallising solutions of the bases in aqueous hydrofluoric acid with VOSO 4 ·3H2 O.
TL;DR: In this article, the thermal properties of composites of poly(methyl methacrylate) and copper were investigated, including the order of reaction and activation energy of the major second stage of pyrolysis.
Abstract: Thermal characteristics of the composites of poly(methyl methacrylate) and copper are reported, including the order of reaction and activation energy of the major second stage of pyrolysis. The randomly-distributed metal particles in the polymer matrix can form paths for heat transfer which determine the mechanism of thermal degradation.
TL;DR: In this paper, the aperture admittance of a rectangular aperture excited from X-band rectangular waveguides has been investigated graphically and the admittance presented to the feed waveguide for inductive window type aperture has also been found.
Abstract: The paper presents investigation on admittance characteristics of a rectangular aperture excited from rectangular waveguides. Complex radiated power is determined from the angular spectrum of plane waves. The aperture admittance is obtained on dividing the complex radiated power by the square of the input reference voltage, which is the dominant mode voltage of a waveguide having the same dimensions as the aperture. Computed results for apertures of different lengths and widths, excited from X-band rectangular waveguide have been presented graphically. The admittance presented to the feed waveguide for inductive window type aperture has also been found.