Showing papers by "Worcester Polytechnic Institute published in 1985"
TL;DR: A statistic for determining the number of different textures in the image is developed and demonstrated and a theory regarding the information processing strategies in human vision motivates the development of a texture feature space.
245 citations
TL;DR: A method is developed by which images resulting from orthogonal projection of rigid planar-patch objects arbitrarily oriented in three-dimensional (3-D) space may be used to form systems of linear equations which are solved for the affine transform relating the images.
Abstract: A method is developed by which images resulting from orthogonal projection of rigid planar-patch objects arbitrarily oriented in three-dimensional (3-D) space may be used to form systems of linear equations which are solved for the affine transform relating the images. The technique is applicable to complete images and to unlabeled feature sets derived from images, and with small modification may be used to transform images of unknown objects such that they represent images of those objects from a known orientation, for use in object identification. No knowledge of point correspondence between images is required. Theoretical development of the method and experimental results are presented. The method is shown to be computationally efficient, requiring O(N) multiplications and additions where, depending on the computation algorithm, N may equal the number of object or edge picture elements.
131 citations
TL;DR: In this paper, the effective radial thermal conductivity and apparent wall heat transfer coefficient in a packed bed were determined experimentally in a laboratory-scale packed bed heat exchanger, where care was taken to use a thermo-couple support cross made out of low conductivity materials and to measure the wall temperature profile.
63 citations
TL;DR: In this article, a mathematical model based on the population balance method is developed for hydrothermal molecular sieve zeolite synthesis, where the material balances for the amorphous, fluid and crystalline phases are based on conservation of unit cells in the three phases.
62 citations
TL;DR: In this paper, simple thermal resistance models of packed-bed heat transfer can be used to derive predictive formulas for the effective axial and radial thermal conductivities and apparent wall heat transfer coefficient.
Abstract: Simple thermal resistance models of packed-bed heat transfer can be used to derive predictive formulas for the effective axial and radial thermal conductivities and apparent wall heat transfer coefficient. In particular, the behavior of the heat transfer parameters over the entire range of Reynolds number can be explained by considering the two asymptotic cases of low Re (solid phase dominant) and high Re (fluid phase dominant).
59 citations
TL;DR: In this paper, various attempts to model the hydrothermal molecular sieve zeolite synthesis process are summarized, divided into several groups: empirical, reaction engineering, particulate-based, and combinations of those.
59 citations
TL;DR: The optical splitting of the A-exciton in Cd0.95 Mn 0.05 Se has been measured and the magnetization curve shows a temperature- broadened step-like increase at B1= 13.0± 0.5 T; three additional steps are expected before a complete ferromagnetic alignment of the pairs is achieved at B ≃ 65 T.
Abstract: The optical splitting of the A-exciton in Cd0.95 Mn 0.05 Sehas been measured at 1.45 K with dc magnetic fields B up to 20 T applied along the c-axis. Magnetization measurements have been made at 1.8 K with pulsed magnetic fields up to 2 8 T. The A-exciton splitting vs. B curve as well as the magnetization vs. B curve show a temperature- broadened step-like increase at B1= 13.0± 0.5 T which is attributed to the magnetic field induced alignment of the antiferromagnetically coupled nearest-neighbor Mn++ion pairs, and yields a value J = -8.7 ± 0.3 K for the antiferromagnetic exchange constant. The magnetization curve shows a second step at B2≃ 25 T; three additional steps are expected before a complete ferromagnetic alignment of the pairs is achieved at B ≃ 65 T.
58 citations
TL;DR: In this paper, the authors studied the factors influencing metastability and crystallite morphology in the hydrothermal synthesis of EU-1 and EU-2 in the sodium, ammonium and hexamethonium (Na, NH 4, HM) cation systems.
56 citations
TL;DR: In this article, the authors explore the shift in feminist thinking from a Beauvoirian sort of position which they define as humanist feminism to an analysis which they call gyocentric feminism.
Abstract: December 1978. At a mostly male conference I hug. chat. eat. drink. listen with my sisters in philosoph! My body avalanches from its recent maternal svvellinps to the plateaus of a folded uterus. milkless breasts. 1 left my baby daughter in Chicago. who used to suckle 90 minutes at a time while I read T/W U’ornen’s Room. For the first time in fifteen months that warm red flow moves through my clitoral canals. No quiet transition. but a body revolution throbbing my back and neck. Clouded in this privately womanstate. I glide around the chandeliered ballroom finding one vvoman’s face and another and another. Fervently u’e comerse about the da\\‘5 papers and each other’s questions. M’s catch up on the news about each other’s lovers or children or jobs. That night in m! restless sleep 1 dream. A ballroom filled with women. hundreds under the chandeliers. a reception after business at the Societ! for \\.omcn in Phil!-\\oph: 1 flit from one group of women to another. in smiling comfort. As I turn to find another friend I see her tall figure across the room. as though o\\,erlookinp the sisterl!, crowd: Simone de Beauvoir. Then. lust hefore I \\yake. a single object. shimmerins: a glass of milk. No other u’oman can occup! our dreams as the mother of feminist philosophi (n,ho in her time. in her view. could only be a writing mother b! leaving her hod! out of motherinr. and I think she was right). Yet most feminists-in the U.S. today find irredeemable flaws in Beauvoir’s star!’ of women’s oppression and her hope for liberation. L+‘hat has happened between the childhood and puberty of our feminist revolution? In this essay I explore the shift in feminist thinking from a Beauvoirian sort of position which I define as humanist feminism to an analysis which I call gyocentric feminism. Humanist feminism defines women’s oppression as the inhibition and distortion of women’s human potential b!, a society that allo\\vs the self-development of men. Most feminists of the nineteenth and twentieth centuries. including feminists of the earl\\ second wa\\.e. ha\\,e been humanist feminists. in recent years a different account of women’s oppression has pained influence. however. partl! groaing,from a critique of humanist feminism. Gvnocentrtc feminism defines women’s oppression as the devaluation and repression of women’s experience.by a masculinist Culture that exalts violence and indtvidualism. It argues for the superiorit), of the values embodied in traditionally female experience. and rejects the values it finds in traditionall!, male dominated institutions. Gynocentric feminism. 1 suggest. contains a more radical critique of male-dominated society than humanist feminism. But at the same time. especially within the social context of anti-feminism backlash. however. its effect can be quieting and accommodating to official powers.
54 citations
TL;DR: In this paper, experimental measurements of effective thermal conductivity and wall heat transfer coefficients were made for stagnant annular fixed beds of low tube-to-particle diameter ratio, and the results were applied to the estimation of effective conductivity in the cylindrical beds of industrial practice.
50 citations
TL;DR: In this paper, the mass transfer coefficient, kd, the surface reaction rate constant, kr, and surface reaction order, r, are discussed in detail and a standardized pair of kd and kr constants is obtained and shown to be a valuable tool in either quantitative descriptions or clarification of the effects of various factors on the crystal growth kinetics.
TL;DR: In this article, a cylindrical internal reflectance using crystals embedded into well-stirred high-pressure autoclaves was developed as a new technique for in situ infrared studies of a variety of catalytic reactions.
TL;DR: In this article, failure handlers and redesigners are introduced to handle the failures that occur during design problem-solving, and failure recovery action and the knowledge involved is presented for each agent.
Abstract: This paper is concerned with how to handle the failures that occur during design problem-solving. Failure handlers and redesigners are introduced. Failure recovery action and the knowledge involved is presented for each agent. The role of suggestions and redesign strategies is discussed. The handling of plan failures is also presented. The paper concludes by surveying other methods of failure handling from the literature.
TL;DR: In this article, it was shown that the images obtained during reconstruction of such holograms are modulated by a system of fringes described by the square of the zero-order Bessel function of the first kind.
Abstract: This paper deals with the quantitative interpretation of time-average holograms of vibrating objects. It is shown that the images obtained during reconstruction of such holograms are modulated by a system of fringes described by the square of the zero-order Bessel function of the first kind. A procedure for quantitative interpretation of these fringes is described and illustrated with examples. The experimental results, obtained directly from the time-average holograms, show good agreement with the exact solution of the differential equation of motion based on the beam theory and with the mode shapes determined by the finite element modeling of the vibrating beam.
TL;DR: In this paper, the impact of nonsinusoidal currents and voltages on the losses of power transformers is discussed and derating curves are explained. And a practical example is presented.
Abstract: This paper deals with the impact of nonsinusoidal currents and voltages on the losses of power transformers. Conventional methods for the determination of the hottest spot temperature are used to predict the loss of life of transformers supplying loads which inject nonsinusoidal currents. Derating curves are explained and a practical example is presented.
TL;DR: Etude experimentale des coefficients de transfert de chaleur et de masse dans des lits fixes de boulettes et de cyclindres creux de different materiaux as mentioned in this paper.
TL;DR: A series of experimental observations on the synthesis of molecular sieve zeolite NaA are reported in this article, where particle size analysis and particle counts are made in order to elucidate the effect of several control variables on particle nucleation.
TL;DR: In this article, the authors give a new way of thinking of these equations by relating these to free boundary problems, and demonstrate that solutions of such a queer differential equation can be thought of as limits of solutions of Free Boundary Problems with n-free boundaries.
Abstract: : Queer differential equations first arose in the work of Harold Grad on controlled thermonuclear fusion. These relate in particular to models for the slow adiabatic evolution and resistive diffusion of a plasma. These are queer in that these share aspects of partial, ordinary and functional differential equations. In this document the authors give a new way of thinking of these equations by relating these to free boundary problems. This is the first of a series of papers intending to demonstrate that solutions of such a queer differential equation can be thought of as limits of solutions of free boundary problems with n-free boundaries. A long term hope is that this work will complement and further refine existing numerical schemes for finding such solutions.
TL;DR: Evidence is presented in support of the thesis that it is both the mode of action of the catalysts and the conformational states of the polysaccharides which must be accounted for if realistic physical and mathematical models of the dynamic events are to be understood.
TL;DR: In this paper, the authors used a double-exposure heterodyne hologram interferometry to study load-deformation characteristics of computer micro-components that were surface mounted on a printed circuit board.
Abstract: Heterodyne hologram interferometry was used to study load-deformation characteristics of computer microcomponents that were surface mounted on a printed circuit board. The board was assembled as a cantilever plate and subjected to cyclic flexure loading according to industry standards. The flexure loading was sinusoidal at 0.1 cps with an amplitude of 1.25 mm (0.050 in.) at the tip of the board. Double-exposure heterodyne holograms were recorded under a number of conditions specified by the magnitude of deflection at the board's tip and the number of accumulated flexure cycles. Data obtained during reconstruction of heterodyne holograms were used to compute displacements and strains along the leads connecting the component to the printed circuit board. The experimental results show that lead displacements were on the order of 1.2 um, while strains were up to 0.054%. The results obtained in this study will be used as input to finite element models of computer microcomponents.
TL;DR: Gutman's model, if one may infer such a thing, posits the existence of relatively "normal" (or "traditional") families and kinship networks among slaves, despite widespread domestic disruption caused by high death rates and by the common occurrence of forced termination of slave unions by sale as discussed by the authors.
Abstract: Whether intended or not, an impression conveyed by Herbert G. Gutman's enormously important monograph, The Black Family in Slavery and Freedom, 1750-1925, is that bondage had less an impact than previously imagined on the post-Civil War household structure and family composition of American blacks. The Gutman model, if one may infer such a thing, posits the existence of relatively "normal" (or "traditional") families and kinship networks among slaves, despite widespread domestic disruption caused by high death rates and by the common occurrence of forced termination of slave unions by sale. When at last it came, emancipation provided ex-slaves the opportunity to reconstitute broken families, to obtain legal sanction for their marriages, and in other ways to indulge powerful familial impulses that had been only partially realizable under slavery. From bondage the black family passed resolutely into freedom, its demographic health less damaged by slavery than it would be by Gilded Age racial discrimination and economic deprivation. I If closely examined, however, this implicit model will be seen to rest mainly on Gutman's remarkable success-a pioneering effort for which he was known long before the appearance of the book-in destroying the sociological assumption that the female-headed black household emerged directly from slavery. Critics have questioned Gutman's methods in statistically discounting matrifocality, and they and others have noted that the black single-parent household became ubiquitous as early as 1880 in urban areas, at least in the North.2 But
TL;DR: The effects of solid entrainment on dehydration rate and product quality are discussed in terms of the loss of intercellular salts and proteins and tearing of muscle fibers caused by high vapor velocity.
Abstract: Data are obtained from the combined microwave and radiant freeze drying of beef steaks. Causes for the high drying rates are explained by the entrainment of solid ice crystals in the vapor during the low pressure drying. The effects of solid entrainment on dehydration rate and product quality are discussed in terms of the loss of intercellular salts and proteins and tearing of muscle fibers caused by high vapor velocity.
TL;DR: A method is presented for determination of the orientation in 3-space of 3-D objects without point correspondence information and without requiring only differential motion between images.
01 Jan 1985
TL;DR: In this paper, a general unsteady state mathematical model with time variant transport and dielectric properties is formulated as a stage wise operation problem and the time-optimal control algorithm taking into consideration the bounds on control and state variables is applied.
Abstract: The time-optimal control algorithm taking into consideration the bounds on control and state variables is applied to microwave freeze drying system. A general unsteady state mathematical model with time variant transport and dielectric properties is formulated as a stage wise operation problem. Microwave power, radiator temperature, water vapor pressure and air pressure are considered controllable. Constraints are set to avoid scorching, melting and gas breakdown. All control variables are kept constant during each stage.
TL;DR: The presence of components other than simple decaying exponentials is shown to imply the violation of detailed balance in the steady-state (which requires energy), and thus, the presence of cyclic pathways in models which accurately represent the kinetic behavior of the channel.
TL;DR: In this paper, the principles of pulsed laser double-exposure hologram interferometry are discussed and procedures for quantitative interpretation of images obtained during reconstruction of holograms are presented and illustrated with representative examples.
Abstract: Principles of pulsed laser double-exposure hologram interferometry are discussed. In this presentation, emphasis is placed on biomedical applications of the method. Procedures for quantitative interpretation of images obtained during reconstruction of holograms are presented and illustrated with representative examples. The procedures for quantitative interpretation of holograms allow determination of translations, rotations, and strains of an object, including determination of and compensation for the object's rigid-body motions. A system for automated interpretation of holograms is also discussed. The results shown relate to in vitro and in vivo studies of tooth and bone motions.
TL;DR: The hydrogenation of acetylene impurity in ethylene has been studied over 0.04 wt% Pd/Al2O3 catalysts modified by Cu.
Abstract: The hydrogenation of acetylene impurity in ethylene has been studied over 0.04 wt% Pd/Al2O3 catalysts modified by Cu. The undesired hydrogenation of ethylene could be suppressed by Cu.14C labelling proved that the intrinsic selectivity is always 95–98% of Cu or gaseous CO reduces the parallel hydrogenation of ethylene on the support, leaving the intrinsic selectivity unchanged.
TL;DR: In this article, the authors present a comprehensive review of the literature on stochastic production simulation, and present a method to solve the problem of predicting the expected generation for different power plants as well as the system's total expected production cost.
Abstract: Predicting expected generation for different power plants as well as the system's total expected production cost is an integral part of quantitative power system analyses. Numerous publications presenting "exact" as well as "approximate" methods of solving stochastic production simulation problem exist in the literature. However, there is no one publication where a comprehensive review of this extremely important topic is presented. Such a review is the subject of this paper.
TL;DR: In this paper, the authors used low concentrations of palladium on several zeolite carriers in the hydrogenation of acetylene in low concentrations in the presence of ethylene in high concentrations.