Showing papers by "Indian Institute of Technology Kharagpur published in 1995"
TL;DR: From the simulation results, it is observed that the performance of the proposed FLANN based equalizer outperforms the other two in terms of bit-error rate (BER) and attainable MSB level over a wide range of eigenvalue spread, signal to noise ratio and channel nonlinearities.
218 citations
TL;DR: In this paper, the mechanism and kinetics of the reaction between CO2 and aqueous solution of sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were investigated at 294-318 K by gas absorption studies using a wetted wall column.
210 citations
TL;DR: Fem is a computer based fuzzy approach where a vector valued marking is used and the generalized method is called gfem in which a matrix-valued marking is adopted.
204 citations
TL;DR: In this paper, the results obtained with regard to grinding forces, specific energy, grinding zone temperature and surface residual stress when using cryogenic cooling and compares them to the results from dry grinding and grinding with soluble oil.
114 citations
TL;DR: In this article, a finite element elasto-viscoplastic solution is presented for a general bearing capacity problem of strip and circular surface footings, where a Mohr-Coulomb yield criterion has been assumed for the soil behaviour.
100 citations
TL;DR: In this paper, the modification of climatic variables, such as rainfall, as a result of change in land use during the premonsoon period over the southern part of West Bengal, India Data analysis supports a decreasing tendency in rainfall during the recent years as a significant increase in agricultural activity during recent years in coastal and inland regions has been stressed.
Abstract: The present work is on the modification of climatic variables, such as rainfall, as a result of change in land use during the premonsoon period over the southern part of West Bengal, India Data analysis supports a decreasing tendency in rainfall during the recent years As a possible factor behind such change, a significant increase in agricultural activity during recent years in coastal and inland regions has been stressed The increase in soil moisture as a result of irrigation hinders the development and intensity of the sea-breeze circulation The low-level moisture supply also decreases, which is an essential criterion for the formation of premonsoon thunderstorms, that is, northwesters So, the increased vegetation or soil moisture is not always likely to increase rainfall activity; rather, mesoscale effects may be more important in some specific areas
82 citations
TL;DR: In this article, a comparison of the energy required for major building materials at the time of construction of single and double storey residential buildings with load bearing walls, and four storey buildings with reinforced concrete construction in India is presented.
81 citations
TL;DR: In this article, the thermal degradation of pure ethylene-vinyl acetate copolymer (EVA, 12% vinyl acetate) and electron beam radiation-cured EVA, cured in the presence of a small amount of sensitizer, has been studied by non-isothermal thermogravimetry and infrared spectroscopy.
78 citations
01 May 1995
TL;DR: In this article, two algorithms are proposed for dynamic state estimation which incorporate the measurement function nonlinearities in the extended Kalman filter (EKF) scheme, and the performance of the schemes are compared with the standard linear EKF scheme under various conditions.
Abstract: Dynamic state estimation in power systems is based on the extended Kalman filter (EKF) scheme The EKF system uses a linearised measurement equation, neglecting the nonlinearities of the measurement function Under certain circumstances (eg large load changes) this leads to degradation in the filter performance Two algorithms are proposed for dynamic state estimation which incorporate the measurement function nonlinearities in the EKF scheme The performance of the schemes are compared with the standard linear EKF scheme under various conditions and comparative results are presented
78 citations
01 Jan 1995
TL;DR: In this article, it was considered that in the case where polyacrylamide chains are grafted on polysaccharide backbones, efficient shear and biodegradation drag reducing and flocculating agents may be developed.
Abstract: Synthetic Polyacrylamide based polymers and polysaccharides such as guar gum, xanthan gum carboxymethylcellulose and starch have been used for long. The Polyacrylamides are easily amenable to shear degradation although they are very efficient drag reducing and flocculating agents even at low ppm concentrations. On the other hand polysaccharides are fairly shear stable but are not very efficient drag reducers and flocculants. Their aqueous solution are also subjected to rapid biodegradation. It was contemplated that in the case where Polyacrylamide chains are grafted on polysaccharide backbones, efficient shear and biodegradation drag reducing and flocculating agents may be developed.
74 citations
TL;DR: A new technique for deriving optimal-sized polygonal schema for triangulated compact 2-manifolds without boundary inO(n) time, wheren is the size of the given triangulationT and Seifert-Van Kampen's theorem is used.
Abstract: We provide a new technique for deriving optimal-sized polygonal schema for triangulated compact 2-manifolds without boundary inO(n) time, wheren is the size of the given triangulationT. We first derive a polygonal schemaP embedded inT using Seifert-Van Kampen's theorem. A reduced polygonal schemaQ of optimal size is computed fromP, where a surjective map from the vertices ofP is retained to the vertices ofQ. This helps detecting null-homotopic (contractible to a point) cycles. Given a cycle of lengthk, we determine if it is null-homotopic inO(n+k logg) time and in ?(n+k) space, whereg is the genus of the given 2-manifold. The actual contraction for a null-homotopic cycle can be computed in ?(nk) time and space. This is a considerable improvement over the previous best-known algorithm for this problem.
TL;DR: In this article, various steel specimens have been surface ground under dry conditions, with soluble oil and by a liquid nitrogen jet, and significant improvements in the chip formation and reduction in specific energy requirement, grinding temperature and residual stress were observed in cryo-grinding when compared with grinding dry and with a soluble oil.
Abstract: Grinding yields high temperature which not only limits the wheel life but also induces tensile residual stresses, micro-cracks, etc. at the ground surfaces. This problem becomes acute when the components are of hard and strong materials and used in dynamic loading. In such cases intensive cooling is essential. In this work various steel specimens have been surface ground under dry conditions, with soluble oil and by a liquid nitrogen jet. Significant improvements in the chip formation and reduction in specific energy requirement, grinding temperature and residual stress were observed in cryo-grinding when compared with grinding dry and with soluble oil.
TL;DR: In this paper, a performance index for the furrow openers of combined seed and fertiliser drills on the basis of output, quality of work and energy input was developed for the purpose of measuring the quality of sowing and correlated with the emergence rate.
Abstract: A performance index was developed for the furrow openers of combined seed and fertiliser drills on the basis of output, quality of work and energy input. Compaction of soil at seed depth, subsoil distribution patterns of seed and fertiliser, soil coverage and row roughness were considered as measures of the quality of sowing and were correlated with the emergence rate. Laboratory tests were also conducted to compare the performance of seven openers, employing shoe, shovel or hoe designs, on a basis of the performance index. Draft requirement of openers was found to increase with opener width and boot wedge angle, whereas lateral and vertical separations between seed and fertiliser were influenced by transverse tube spacing and boot geometry, respectively. A hoe type opener having 30° wedge angle, 40 mm transverse tube spacing and a baffle plate at its boot performed better than other openers.
TL;DR: In this article, a genetic algorithm is presented for obtaining efficient facility layout, where the population maintained by the genetic algorithm for facility layout should consist of feasible solutions only, and a new efficient crossover operator is developed.
Abstract: Facility layout is an important aspect of designing any manufacturing setup. However, the problem of finding optimal layouts is hard and deterministic techniques are not computationally feasible. In this work a genetic algorithm is presented for obtaining efficient layouts. The different aspects involved in the design of efficient genetic algorithms are discussed in detail. It is shown that the population maintained by the genetic algorithm for facility layout should consist of feasible solutions only. A new efficient crossover operator is developed. Experimental results obtained with the proposed algorithm on test problems taken from the literature are promising.
TL;DR: In this article, a new methodology is presented that is applicable to a large class of nonlinear continuous-time systems, by defining a set of Hartley modulating functions for characterizing the continuous process signals.
Abstract: Most of the existing approaches to identification of nonlinear dynamic systems involve matching a given input-output behaviour with empirical discrete-time approximations such as artificial neural networks, Kolmogorov-Gabor polynomials, radial basis function networks, etc. Techniques for dealing with physically-based continuous-time models are either applicable to only a restricted class of systems or are computationally very demanding. In this paper a new methodology is presented that is applicable to a large class of nonlinear continuous-time systems, by defining a set of Hartley modulating functions for characterizing the continuous process signals. The advantages of this new class of modulating functions are that a set of algebraic equations with real coefficients results, the formulations are free from boundary conditions, and the computations can be made using fast algorithms for the discrete Hartley transformation. The resulting estimation scheme is applied to different categories of nonlinear syst...
TL;DR: The singular value decomposition (SVD) and QR with column pivoting factorization (QRcp) are the transformations used and have also been used to devise a new approach for the assessment of the convergence of the NN's, which is an alternative to the conventional output error analysis.
Abstract: Orthogonal transformation, which can lead to compaction of information, has been used in two ways to optimize on the size of feedforward networks: 1) through the selection of optimum set of time-domain inputs, and the optimum set of links and nodes within a neural network (NN); and 2) through the orthogonalization of the data to be used in NN's, in case of processes with periodicity. The proposed methods are efficient and are also extremely robust numerically. The singular value decomposition (SVD) and QR with column pivoting factorization (QRcp) are the transformations used. SVD mainly serves as the null space detector; QRcp coupled with SVD is used for subset selection, which is one of the main operations on which the design of the optimal network is based. SVD has also been used to devise a new approach for the assessment of the convergence of the NN's, which is an alternative to the conventional output error analysis. >
TL;DR: In this article, the authors considered parametric instability of a three-layered symmetric sandwich beam subjected to a periodic axial load under nine different boundary conditions and investigated the influence of static load parameter and core-thickness parameter on the system loss factor.
TL;DR: In this paper, a finite element analysis for the free vibration behavior of point supported laminated composite cylindrical shells is presented based on the assumptions of the first order shear deformation theory for thin, shallow shells.
TL;DR: In this article, the surface energy of EPDM, silicone rubber, and their 50 : 50 blend during aging was determined by contact angle measurement using water and formamide as the probe liquids.
Abstract: Surface energy of EPDM, silicone rubber, and their 50 : 50 (by weight) blend during aging was determined by contact angle measurement using water and formamide as the probe liquids. The surface energy increases initially with aging time. The results are explained on the basis of the polar component of the surface energy. Blending offers a good degree of protection toward aging of EPDM rubber. The generation of polar groups during aging is confirmed by IR and ESCA investigations. © 1995 John Wiley & Sons, Inc.
TL;DR: In this article, carbon black was used to improve the physical properties of zinc sulfonated polyethylene (ZS) and polypropylene (propylene) polymers.
TL;DR: Though they do not ensure the attainment of the global optimum, solutions from the process of simulated annealing successfully identify the main cluster which is very close to the reported global optimum predicted by pure random methods and genetic algorithms.
TL;DR: The axisymmetric peristaltic flow of a viscous incompressible Newtonian fluid through a circular tube of varying cross section has been studied when the wave propagating along the wall of the tube is sinusoidal and the initial flow is Hagen-Poiseuille as mentioned in this paper.
TL;DR: In this article, the authors report a method for control of chaos in the DC-DC buck converter, which differs from the existing ones and is particularly useful for piecewise linear systems with switching nonlinearity.
Abstract: The authors report a method for control of chaos in the DC-DC buck converter. The method differs from the existing ones and is particularly useful for piecewise linear systems with switching nonlinearity. >
TL;DR: In this article, two new versatile chemical routes were proposed for the coprecipitation of the desired metal nitrates from their aqueous solution, in presence of a water soluble polymer-polyvinyl alcohol (PVA), by triethyl ammonium carbonate solution.
Abstract: Ultrafine (⩽ 150 nm) powders of spinels [MFe2O4 where M = Ni(II), Co(II) and Zn(II)]; rare-earth orthoferrites [RFeO3 where R = Sm, Nd and Gd], and rare-earth garnets [R3Fe3O12 where R = Sm, Nd and Gd] with good purity and chemical homogeneity were prepared through two new versatile chemical routes. The first route involved the coprecipitation of the desired metal nitrates from their aqueous solution, in presence of a water soluble polymer-polyvinyl alcohol (PVA), by triethyl ammonium carbonate solution. The other process involved complete evaporation of a mixture of optimum amounts of PVA and the desired aqueous metal nitrate solutions, with and without the addition of optimum amounts of urea when the mixture was evaporated to a pasty mass. In addition, detailed study on the reported potassium ferricyanide route was also carried out for the production of the rare-earth orthoferrite powders. The various precursor as well as the heat-treated mixed-oxide powders, prepared through each of the routes, were compared by the physical characterization studies involving thermal gravimetry and differential scanning calorimetry, infrared spectroscopy, X-ray powder diffraction, transmission electron microscopy, and room temperature magnetic measurements.
TL;DR: In this paper, the authors derived the fatigue strength distribution as a function of the number of cycles to failure in the stationary random loading process and used the stress-strength interference technique to calculate reliability.
TL;DR: In this article, ternary thin films have been deposited on glass substrates at room temperature by electron beam evaporation, using the source materials prepared in their laboratory by direct reaction of high purity elemental Cd(99.9999%), Se( 99.999%) and Te(99,999%).
TL;DR: In this paper, a finite element analysis for studying the free vibration behavior of generalized doubly curved laminated composite shells is presented using eight-noded curved quadrilateral isoparametric finite elements, which assumes first-order shear deformation theory for thin and shallow shells, and also considers the two principal radii of curvature and the radius of cross-curvature.
TL;DR: In this paper, the parametric instability behavior of a plate subjected to localized in-plane compressive or tensile periodic edge loading is studied, considering the effects of transverse shear deformation and rotary inertia.