Showing papers by "Indian Institute of Technology Kharagpur published in 1982"
TL;DR: A nonparametric algorithm is presented for the hierarchical partitioning of the feature space that generates an efficient partitioning tree for specified probability of error by maximizing the amount of average mutual information gain at each partitioning step.
Abstract: A nonparametric algorithm is presented for the hierarchical partitioning of the feature space. The algorithm is based on the concept of average mutual information, and is suitable for multifeature multicategory pattern recognition problems. The algorithm generates an efficient partitioning tree for specified probability of error by maximizing the amount of average mutual information gain at each partitioning step. A confidence bound expression is presented for the resulting classifier. Three examples, including one of handprinted numeral recognition, are presented to demonstrate the effectiveness of the algorithm.
202 citations
TL;DR: In this paper, it was shown that amorphous silica can be reduced to polycrystalline silicon by magnesium at a comparatively low temperature (about 600°C) using differential thermal analysis and thermogravimetric analysis.
111 citations
TL;DR: In this paper, the effect of increase in concentration parameter α of the dust particles is to increase the magnitude of the longitudinal fluid phase velocityu and also the magnitude is becoming maximum on the plate and decreasing along the plate withx.
Abstract: Both the drag force due to slip and the transverse force due to slip-shear have been considered in boundary layer equations. The solution has been found in a power series of non-dimensionalx, x being the distance in the down-stream direction. Solutions for high slip region and small slip region characterised byx≪1 andx≫1 respectively, have been found separately. In the high slip region the effect of increase in concentration parameter α of the dust particles is to increase the magnitude of the longitudinal fluid phase velocityu. Also the magnitude of the longitudinal particle slip velocityup-u is becoming maximum on the plate and decreasing along the plate withx. The transverse particle velocityvp is independent of α but it is directly proportional to β, the transverse force coefficient. An interesting result is thatvp is assuming small positive value on the plate. The transverse force has taken an important role in migration of particles away from the plate. In the small slip region the flow of dust particles is mainly governed by the fluid-phase. The effect of α on the flow field in this region is to decrease the boundary layer thickness. In this region the particles are having some tendency to accumulate near the plate. Lastly, it has been found that the shearing stress, skinfriction and the dimensionless drag-coefficient on the plate increase with increase of α.
106 citations
TL;DR: In this paper, the authors deal with the minimization of an objective function which incorporates two conflicting criteria; cost minimization and closeness rating maximization, for facilities design problems, and a heuristic approach is developed which takes an initial layout and improves it step by step using a pairwise exchange routine.
Abstract: This paper deals with the minimization of an objective function which incorporates two conflicting criteria; cost minimization and closeness rating maximization, for facilities design problems. The objective function represents the difference of materials handling cost and the closeness rating with predefined weights assigned to both criteria. A heuristic approach is developed which takes an initial layout and improves it step by step using a pairwise exchange routine.
94 citations
TL;DR: In this article, the phase distribution of a linear array of discrete sources for a specified radiation pattern and a fixed aperture amplitude function is determined by transforming the finite series representing the array factor into an infinite series each term in the form of an integral.
Abstract: The method of determination of the phase distribution of a linear array of discrete sources for a specified radiation pattern and a fixed aperture amplitude function is presented. The finite series representing the array factor is transformed into an infinite series each term of which is in the form of an integral. Synthesis is carried out from asymptotic evaluation of the integral by the stationary phase method. Computed results for sector and cosecant beam are presented.
91 citations
TL;DR: This paper showed that the bonding between jute fiber and rubber matrix is poor without any bonding agent and that adding 5 phr silica is essential and sufficient for promoting adhesion between fiber and matrix of a mix containing 5 phr resorcinol and 3.2 phr.
Abstract: The following conclusions can be drawn from the above results and discussion: (1) The bonding between jute fiber and rubber matrix is poor without any bonding agent. (2) Addition of 5 phr silica is essential and sufficient for promoting adhesion between fiber and matrix of a mix containing 5 phr resorcinol and 3.2 phr (3) The jute fiber will act as a reinforcing filler only when added above a volume loading of 10 percent. (4) The aging resistance of jute fiber reinforced natural rubber composites is excellent beyond a fiber loading of 10 volume percent.
88 citations
TL;DR: In this article, an expression for the complex admittance of a radiating slot in the ground plane of a microstripline is obtained from the complex radiated power and discontinuity in the modal voltage.
Abstract: An expression for the complex admittance of a radiating slot in the ground plane of a microstripline is obtained from the complex radiated power and discontinuity in the modal voltage. The complex radiated power is obtained from the angular spectrum of plane waves. The electric field distribution in the microstripline, required for the determination of the discontinuity in the modal voltage, is determined from the analysis presented by Yamashita and Atsuki. The theoretical results are compared with experimental data.
82 citations
TL;DR: In this article, it was shown that the aging resistance of XNBR-jute fiber composites is increased with the addition of jute fiber to the bonding agent and fibers.
Abstract: Silica is not an essential component in the bonding system in XNBR-jute fiber systems. Mechanical anisotropy is observable only at the higher fiber loadings (40 phr and above) in XNBR-jute fiber composites. In composites containing sufficient amounts of bonding agent and fibers for tensile-strength anisotropy to be observed, tensile failure occurs by both fiber breakage and debonding. Fibers increase the aging resistance of XNBR composites. Mill shrinkage and green strength of XNBR improve, while Mooney viscosity increases and scorch time decreases with the addition of jute fiber to XNBR.
78 citations
TL;DR: In this paper, the effect of carbon black on the processing characteristics and physical properties of jute fiber-reinforced composites and the role of silica and carbon black in promoting the adhesion between Jute fiber and natural rubber have been studied.
Abstract: The effect of carbon black on the processing characteristics and physical properties of jute fiber-reinforced composites and the role of silica and carbon black in promoting the adhesion between jute fiber and natural rubber have been studied. It was found that presence of silica is not essential to develop adhesion between fiber and rubber in the presence of carbon black. However, silica and carbon black can improve adhesion by minimizing the resin formation and controlling it to a low molecular weight species. Processing properties like green strength and mill shrinkage are improved by the addition of fiber. Carbon black does not affect mill shrinkage, but improves the green strength. Breakage of jute fiber during mixing is severe, but the extent of breakage is not affected by the presence of carbon black. The minimum loading of fiber to achieve reinforcement is reduced in the presence of carbon black. It was also found that the presence of clay in jute fiber rubber composites impairs the properties. Scanning electron microscopy (SEM) has been used to assess the failure criteria.
75 citations
TL;DR: In this article, a chance-constrained formulation for a zero-one goal programming problem whose coefficients in the technological matrix are stochastic is presented with a numerical example.
Abstract: A chance-constrained formulation is presented for a zero-one goal programming problem whose coefficients in the technological matrix are stochastic. The model is presented with a numerical example. A capital budgeting problem is taken for illustration.
65 citations
TL;DR: In this article, the asymptotic behavior of the solution of an electrically conducting viscous incompressible fluid in a rotating system under the influence of a uniform transverse magnetic field is investigated when one of the plates is set into motion with the time dependent velocity in its own plane.
TL;DR: In this paper, the dip-dry method by which thin films of Sb2S3 were deposited is described in detail, and the structure, composition and electronic properties of the films were studied using X-ray diffraction, scanning electron microscopy and reflectance and photoconductivity measurements.
TL;DR: In this paper, the entropy generation in a counterflow heat exchanger has been analyzed in detail and expressions have been derived in terms of relevant non-dimensional parameters, and an expression for entropy production in the case of nearly ideal heat exchangers with nearly balanced capacity rate has been derived which matches closely with exact calculation.
TL;DR: In this article, a review highlights the recent developments in carbazole-based polymer systems which have taken place along three main directions: (a) syntheses of homopolymers, copolymers and copolycondensates, and (b) chemical modification of these polymer systems to cation radical complexes, nuclear substituted polymeric materials, ion-exchange resins, charge-transfer complexes, and polyolymeric materials containing donor-acceptor units.
TL;DR: In this paper, the photoelectrochemical behavior of chemically deposited Sb2Se3 thin film in aqueous solution is studied and the dependence of the deposition on pH, temperature and deposition mixture is described.
TL;DR: In this article, a new operational matrix for "Stretch" via Walsh functions is presented and some interesting properties of this matrix and its role in the solution of certain functional differential equations are discussed.
Abstract: This correspondence presents a new operational matrix for "Stretch" via Walsh functions and discusses some interesting properties of this matrix and its role in the solution of certain functional differential equations. The solutions of differential equations are obtained in a series of Walsh functions. The results are piecewise constant with minimal mean-square error. The single term approximation combined with the technique of extension [8] reduces the computational effort to a minimum.
TL;DR: In this paper, the peroxide-and sulphur-cured natural rubber vulcanizates, both unfilled and filled, have been studied using scanning electron microscopy.
TL;DR: In this paper, the performance of a thin layer of a highly wear-resistant and friction-reducing material such as TiC, TiN, Ti(C,N), Al2O3 and Ti(c,N,O) was investigated.
TL;DR: In this article, the interaction of the vulcanization system (conventional and EV) and filler (HAF black, N330) concentration on the technical properties and network structure of NR vulcanizates was studied.
Abstract: We have studied the interaction of the vulcanization system (conventional and EV) and filler (HAF black, N330) concentration on the technical properties and network structure of NR vulcanizates. At lower loadings of filler, a marked difference in values of resilience, hardness, tear strength, elongation at break and tensile strength was observed between the vulcanizates of the two systems; whereas, this difference is minimized at higher loadings of filler. At all loadings, modulus, flex cracking resistance, dynamic set, and compression set are higher for the conventional system than for the EV one. But irrespective of filler concentration, heat buildup is higher for the EV system than for the conventional system. At lower loadings of filler, abrasion loss is independent of the vulcanization system, but at higher loadings, abrasion loss for the EV system is more than for that of the conventional one. Addition of HAF black at 5 phr loading increases total crosslink density and the proportion of pol...
TL;DR: In this article, an amorphous and low molecular weight polyesterimide has been characterized, and the polymer was found to be thermostable and soluble in highly polar solvents.
Abstract: Polyesterimide offers a class of resin which combines the advantage of high temperature stability with ease of process-ability. Gum rosin, the exudate of pine trees, has been developed as the raw material for preparation of polyesterimide. Abietic acid of rosin reacts readily with maleic anhydride to form the Diels-Alder adduct, which reacts with p-amino benzoic acid to produce a dicarboxylic acid containing an internal imide group. The dicarboxylic acid reacts with diethylene glycol under melt polycondensation at higher temperature (260–300°C)to produce polyesterimide. The polymer is found to be soluble in highly polar solvents. The polymer is amorphous and of low molecular weight. Thermal stability of the polymer has been characterized, and the polymer was found to be thermostable.
TL;DR: Gum and filled vulcanizates with both conventional and EV systems were tested in a De Mattia flexing machine at two temperatures, and the fracture surfaces were subjected to chemical analyses and SEM studies as mentioned in this paper.
Abstract: Gum and filled vulcanizates with both conventional and EV systems were tested in a De Mattia flexing machine at two temperatures, and the fracture surfaces were subjected to chemical analyses and SEM studies. The study shows that flexing failure is not accompanied by any major change in network structure. SEM studies show ductile failure of gum mixes. HAF black filled mixes show brittle failure which changes to quasi-ductile with the addition of antioxidant. At 100°C, flow of the matrix is more predominant.
TL;DR: In this paper, the role of the CO2 equilibrium pressure in relation to the k.c. was examined in the decomposition of CaCO3 and it was shown that non-isothermal experiments must sometimes yield a value of activation energy different from the value obtained from isothermal experiments.
Abstract: Some specific factors which may cause the kinetic compensation effect (k.c.e.) during the decomposition of CaCO3 are identified. The role of the CO2 equilibrium pressure is examined in relation to the k.c.e. The article also shows why non-isothermal experiments must sometimes necessarily yield a value of activation energy different from the value obtained from isothermal experiments.
TL;DR: In this article, a laterally loaded free-head pile embedded in a two-layer soil system, using an elastic approach, is presented, and it is concluded that pile flexibility factor, thickness of surface layer, and elastic properties of the layers govern the lateral response of a pile.
Abstract: Typical results for pile head displacement and maximum moment in nondimensional terms, for a laterally loaded free-head pile embedded in a two-layer soil system, using elastic approach, is presented. It is concluded that pile flexibility factor, thickness of surface layer, and elastic properties of the layers govern the lateral response of a pile. Depth of surface layer controlling the behavior of a pile depends significantly on pile flexibility factor and stiffness of the surface layer. Reductions in pile head displacement for flexible pile and maximum moment for relatively stiff pile, which are beneficial in practice, are greatly achieved by a stiff surface layer extending one-tenth the length of a pile. An illustrative example is solved to show the applicability of the results.
TL;DR: In this paper, the authors investigated the pressure drop during forced convection boiling of R-12 under swirl flow inside a horizontal tube and presented a correlation between the swirl flow boiling pressure drop in terms of the twist ratio and the plain flow boiling data calculated by the Martinelli-Nelson model.
Abstract: This investigation deals with the pressure drop during forced convection boiling of R-12 under swirl flow inside a horizontal tube. Plain flow and swirl flow pressure drop data are reported for an electrically heated, horizontal, stainless steel, round test-section fitted with twisted tapes having twist ratios from 3.76 to 10.15. A correlation has been presented expressing the swirl flow boiling pressure drop in terms of the twist ratio and the plain flow boiling pressure drop calculated by the Martinelli-Nelson model. The proposed correlation predicts the swirl flow data to within ± 20 percent of the observed values.
TL;DR: The method of Lee and the simple application of graph theory seem to give different answers for flow networks as mentioned in this paper, and the method whereby graph theory can be extended to give correct results is explained.
Abstract: The method of Lee and the simple application of graph theory seem to give different answers for flow networks. Lee's method is correct. The method whereby graph theory can be extended to give correct results is explained.
TL;DR: In this paper, a study of electronic conductivity using the d.c. polarization technique has been carried out in α and β-AgI which shows the former is a hole and the latter an electron conductor.
TL;DR: It is observed that consideration of the mechanical influence of the external tissues and the inertial forces makes the derived stress field quite close to the experimental results reported recently by Fung et al. (1979), in comparison to the results of Cheung etal.
TL;DR: In this article, a method of preparation of PbI 2 films by iodination of chemically deposited PbS films is described, and X-ray characterization of these films show that they are poly-crystalline in nature and the crystallites are preferentially oriented with c-axis perpendicular to the plane of the substrates.
TL;DR: In this article, the authors measured the electrical conductivity of tin dioxide doped with antimony and found that the antimony oxide forms a substitutional solid solution and doubly ionized oxygen vacancies are predominant defects.
Abstract: Electrical conductivity (σ) of tin dioxide doped with antimony has been measured as functions of temperature and oxygen partial pressure (p02>
). Variation of electrical conductivity is explained by assuming that the antimony oxide forms a substitutional solid solution and doubly ionized oxygen vacancies are predominant defects. Above −10−5 atm oxygen partial pressure antimony ions are present predominantly in the pentavalent state in tin dioxide lattice. However, it is converted to the trivalent state below this oxygen partial pressure accompanied by a sudden rise in conductivity.