Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2000

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 49861 - 49890 of 58838

Full-Text Articles in Entire DC Network

Photostability Enhancement Of An Azobenzene Photonic Polymer, A. Galvan-Gonzalez, K. D. Belfield, G. I. Stegeman, M. Canva, K. -P. Chan, K. Park, L. Sukhomlinova, R. J. Twieg Jan 2000

Photostability Enhancement Of An Azobenzene Photonic Polymer, A. Galvan-Gonzalez, K. D. Belfield, G. I. Stegeman, M. Canva, K. -P. Chan, K. Park, L. Sukhomlinova, R. J. Twieg

Faculty Bibliography 2000s

We have found that the presence of a methacrylate group on an azobenzene electro-optic chromophore can provide an enhancement in photostability of up to one or two orders of magnitude. Systematic studies involving the change in chromophore structure and atmospheric environment indicate that the photostabilization is due to antioxidant action by the unsaturated functional group.

Go to article

Understanding The Customer Base Of Service Providers: An Examination Of The Differences Between Switchers And Stayers, Jaishankar Ganesh, Mark J. Arnold, Kristy E. Reynolds Jan 2000

Understanding The Customer Base Of Service Providers: An Examination Of The Differences Between Switchers And Stayers, Jaishankar Ganesh, Mark J. Arnold, Kristy E. Reynolds

Faculty Bibliography 2000s

Creating and maintaining customer loyalty has become a strategic mandate in today's service markets. Recent research suggests that customers differ in their value to a firm, and therefore customer retention and loyalty-building efforts should not necessarily be targeted to all customers of a firm. Given these sentiments, it is becoming increasingly necessary for firms to have a thorough understanding of their customer base. Yet current knowledge is limited in providing insights to firms regarding the differences within their customer base. This research comprises two studies in which the authors examine the differences among internal customer groups in a service industry. …

Go to article

Scanning Probe Metrology In The Presence Of Surface Charge, J. E. Griffith, E. M. Kneedler, S. Ningen, A. Berghaus, C. E. Bryson Iii, S. Pau, E. Houge, T. Shofner Jan 2000

Scanning Probe Metrology In The Presence Of Surface Charge, J. E. Griffith, E. M. Kneedler, S. Ningen, A. Berghaus, C. E. Bryson Iii, S. Pau, E. Houge, T. Shofner

Faculty Bibliography 2000s

Surface charge on insulating samples can be a significant source of error for scanning probe microscopes. We have found that it is possible to operate a scanning force microscope in a manner that makes it relatively immune to charge-induced forces while still allowing the probe tip to nondestructively follow the surface topography. The need to maintain close charge balance on the sample is thus obviated. We have used this strategy to perform critical dimension measurements on optical photomasks with the Surface/Interface Stylus NanoProfilometer. This instrument incorporates a servoed force-balance sensor. Surface topography is determined by touching the surface with contact …

Go to article

Augustus Desire Waller, Louis J. Acierno Jan 2000

Augustus Desire Waller, Louis J. Acierno

Faculty Bibliography 2000s

No abstract provided.

Go to article

Adolph Fick: Mathematician, Physicist, Physiologist, Louis J. Acierno Jan 2000

Adolph Fick: Mathematician, Physicist, Physiologist, Louis J. Acierno

Faculty Bibliography 2000s

No abstract provided.

Go to article

James Bryan Herrick - Profiles In Cardiology, Louis J. Acierno, L. Timothy Worrell Jan 2000

James Bryan Herrick - Profiles In Cardiology, Louis J. Acierno, L. Timothy Worrell

Faculty Bibliography 2000s

No abstract provided.

Go to article

Automatic Modeling Of Knee-Joint Motion For The Virtual Reality Dynamic Anatomy (Vrda) Tool, Yohan Baillot, Jannick P. Rolland, Kuo-Chi Lin, Donna L. Wright Jan 2000

Automatic Modeling Of Knee-Joint Motion For The Virtual Reality Dynamic Anatomy (Vrda) Tool, Yohan Baillot, Jannick P. Rolland, Kuo-Chi Lin, Donna L. Wright

Faculty Bibliography 2000s

This paper presents a method and algorithms for automatic modeling of anatomical joint motion. The method relies on collision detection to achieve stable positions and orientations of the knee joint by evaluating the relative motion of the tibia with respect to the femur (for example, flexion-extension). The stable positions then become the basis for a look-up table employed in the animation of the joint. The strength of this method lies in its robustness to animate any normal anatomical joint. It is also expandable to other anatomical joints given a set of kinematic constraints for the joint type as well as …

Go to article

Standardizing The Nomenclature Of Martian Impact Crater Ejecta Morphologies, Nadine G. Barlow, Joseph M. Boyce, François M. Costard, Robert A. Craddock, James B. Garvin, Susan E. H. Sakimoto, Ruslan O. Kuzmin, David J. Roddy, Laurence A. Soderblom Jan 2000

Standardizing The Nomenclature Of Martian Impact Crater Ejecta Morphologies, Nadine G. Barlow, Joseph M. Boyce, François M. Costard, Robert A. Craddock, James B. Garvin, Susan E. H. Sakimoto, Ruslan O. Kuzmin, David J. Roddy, Laurence A. Soderblom

Faculty Bibliography 2000s

The Mars Crater Morphology Consortium recommends the use of a standardized nomenclature system when discussing Martian impact crater ejecta morphologies. The system utilizes nongenetic descriptors to identify the various ejecta morphologies seen on Mars. This system is designed to facilitate communication and collaboration between researchers. Crater morphology databases will be archived through the U.S. Geological Survey in Flagstaff, where a comprehensive catalog of Martian crater morphologic information will be maintained.

Go to article

Identification Of Surface Chemical Functional Groups Correlated To Failure Of Reverse Osmosis Polymeric Membranes, Sharon Beverly, Sudipta Seal, Seungkwan Hong Jan 2000

Identification Of Surface Chemical Functional Groups Correlated To Failure Of Reverse Osmosis Polymeric Membranes, Sharon Beverly, Sudipta Seal, Seungkwan Hong

Faculty Bibliography 2000s

The goal of this study is to identify the causes of membrane failure observed during a 15-month operation of a low pressure reverse osmosis (RO) membrane pilot plant to treat a highly organic surface water from the Hillsborough River in Tampa, Florida, using various surface analytical techniques. Three different commercial RO membranes, made of cellulose acetate or polyamide, were used in this pilot study, and all of these membranes showed performance deterioration presumably due to membrane fouling and degradation at given experimental conditions. In order to elucidate the mechanisms of membrane failure, scanning electron microscopy with energy dispersive spectrometry (SEM/EDS), …

Go to article

Association Of Beta 1 Integrin With Focal Adhesion Kinase And Paxillin In Differentiating Schwann Cells, Li-Mei Chen, Debora Bailey, Cristina Fernandez-Valle Jan 2000

Association Of Beta 1 Integrin With Focal Adhesion Kinase And Paxillin In Differentiating Schwann Cells, Li-Mei Chen, Debora Bailey, Cristina Fernandez-Valle

Faculty Bibliography 2000s

Schwann cells (SCs) differentiate into a myelinating cell when simultaneously adhering to an axon destined for myelination and basal lamina. We are interested in defining the signaling pathway activated by basal lamina. Using SC/sensory neuron (N) cocultures, we identified beta 1 integrin and F-actin as components of a pathway leading to myelin gene expression and myelination (Fernandez-Valle et al., 1994, 1997). Here, we show that focal adhesion kinase (FAK) and paxillin are constitutively expressed by SCs contacting axons in the absence of basal lamina. Tyrosine phosphorylation of FAK and paxillin increases as SCs form basal lamina and differentiate. FAK and …

Go to article

Electron Beam-Induced Increase Of Electron Diffusion Length In P-Type Gan And Algan/Gan Superlattices, Leonid Chernyak, Andrei Osinsky, Vladimir Fflyigin, E. F. Schubert Jan 2000

Electron Beam-Induced Increase Of Electron Diffusion Length In P-Type Gan And Algan/Gan Superlattices, Leonid Chernyak, Andrei Osinsky, Vladimir Fflyigin, E. F. Schubert

Faculty Bibliography 2000s

The diffusion length, L, of electrons in Mg-doped p-GaN grown by metal-organic chemical vapor deposition was found to increase linearly from 0.55 to 2.0 mu m during 1500 s of electron beam irradiation. Similar trends were observed for p-type Mg-doped GaN and AlGaN/GaN superlattices grown by molecular-beam epitaxy. While the electron diffusion length in p-(Al)GaN depends on irradiation time, the diffusion length of holes in n-GaN remains unchanged, with L similar to 0.35 mu m. We attribute the observed diffusion length change in p-(Al)GaN to an increase in the minority carrier lifetime. This increase is likely due to electron beam-induced …

Go to article

Electron Beam And Optical Depth Profiling Of Quasibulk Gan, L. Chernyak, A. Osinsky, G. Nootz, A. Schulte, J. Jasinski, M. Benamara, Z. Lilental-Weber, D. C. Look, R. J. Molnar Jan 2000

Electron Beam And Optical Depth Profiling Of Quasibulk Gan, L. Chernyak, A. Osinsky, G. Nootz, A. Schulte, J. Jasinski, M. Benamara, Z. Lilental-Weber, D. C. Look, R. J. Molnar

Faculty Bibliography 2000s

Electron beam and optical depth profiling of thick (5.5-64 mu m) quasibulk n-type GaN samples, grown by hydride vapor-phase epitaxy, were carried out using electron beam induced current (EBIC), microphotoluminescence (PL), and transmission electron microscopy (TEM). The minority carrier diffusion length, L, was found to increase linearly from 0.25 mu m, at a distance of about 5 mu m from the GaN/sapphire interface, to 0.63 mu m at the GaN surface, for a 36-mu m-thick sample. The increase in L was accompanied by a corresponding increase in PL band-to-band radiative transition intensity as a function of distance from the GaN/sapphire …

Go to article

Feasibility Tests Of Transmission X-Ray Photoelectron Emission Microscopy Of Wet Samples, Gelsomina De Stasio, B. Gilbert, T. Nelson, R. Hansen, J. Wallace, D. Mercanti, M. Capozi, P. A. Baudat, P. Perfetti, G. Margaritondo, B. P. Tonner Jan 2000

Feasibility Tests Of Transmission X-Ray Photoelectron Emission Microscopy Of Wet Samples, Gelsomina De Stasio, B. Gilbert, T. Nelson, R. Hansen, J. Wallace, D. Mercanti, M. Capozi, P. A. Baudat, P. Perfetti, G. Margaritondo, B. P. Tonner

Faculty Bibliography 2000s

We performed feasibility tests of photoelectron emission spectromicroscopy of wet samples in the water window (285-532 eV) soft x-ray spectral region. Water was successfully confined in an ultrahigh vacuum compatible compartment with x-ray transparent sides. This water cell was placed in the MEPHISTO spectromicroscope in a transmission geometry, and complete x-ray absorption spectra of the water window region were acquired. We also show micrographs of test samples, mounted outside of the compartment, and imaged through the water. This technique can be used to study liquid chemistry and, at least to the micron level, the microstructure of wet samples. Possibilities include …

Go to article

Crossover Behavior In Dynamics Of Frozen Ferrofluids, Xiaodong Duan, Jinlong Zhang, Weili Luo Jan 2000

Crossover Behavior In Dynamics Of Frozen Ferrofluids, Xiaodong Duan, Jinlong Zhang, Weili Luo

Faculty Bibliography 2000s

The imaginary part of susceptibility, chi", in frozen ferrofluids was measured as functions of temperature, frequency, and concentration of magnetic particles. In a very dilute region, where magnetic interaction is negligible, the relaxation time is mainly determined by Neel's relaxation in isolated particles and the frequency-dependent peak temperature in chi"(T), T-p, obeys the Arrhenius law. In the moderate concentration range, T-p has a Vogel-Fulcher (VF) relaxation with the measuring frequency. However, for concentration larger than a certain value, deviation from VF law occurs. Simulations show that the VF relation could be attributed to Ising spin-glass-like random and frustrated interaction between …

Go to article

Demand Reduction In Multiunit Auctions: Evidence From A Sportscard Field Experiment, John A. List, David Lucking-Reiley Jan 2000

Demand Reduction In Multiunit Auctions: Evidence From A Sportscard Field Experiment, John A. List, David Lucking-Reiley

Faculty Bibliography 2000s

No abstract provided.

Go to article

Duration And Exposure To Virtual Environments: Sickness Curves During And Across Sessions, Robert S. Kennedy, Kay M. Stanney, William P. Dunlap Jan 2000

Duration And Exposure To Virtual Environments: Sickness Curves During And Across Sessions, Robert S. Kennedy, Kay M. Stanney, William P. Dunlap

Faculty Bibliography 2000s

Although simulator sickness is known to increase with protracted exposure and to diminish with repeated sessions, limited systematic research has been performed in these areas. This study reviewed the few studies with sufficient information available to determine the effect-that exposure duration and repeated exposure have on motion sickness. This evaluation confirmed that longer exposures produce more symptoms and that total sickness subsides over repeated exposures. Additional evaluation was performed to investigate the precise form of this relationship and to determine whether the same form was generalizable across varied simulator environments. The results indicated that exposure duration and repeated exposures are …

Go to article

Activation Of A Plasmodium Falciparum Cdc2-Related Kinase By Heterologous P25 And Cyclin H - Functional Characterization Of A P. Falciparum Cyclin Homologue, Karien Le Roch, Claude Sestier, Dominique Dorin, Norman Waters, Barbara Kappes, Debopan Chakrabarti, Laurent Meijer, Christina Doerig Jan 2000

Activation Of A Plasmodium Falciparum Cdc2-Related Kinase By Heterologous P25 And Cyclin H - Functional Characterization Of A P. Falciparum Cyclin Homologue, Karien Le Roch, Claude Sestier, Dominique Dorin, Norman Waters, Barbara Kappes, Debopan Chakrabarti, Laurent Meijer, Christina Doerig

Faculty Bibliography 2000s

Several Plasmodium falciparum genes encoding cdc2-related protein kinases have been identified, but the modalities of their regulation remains largely unexplored. Zn the present study, we investigated the regulation in vitro of PfPK5, a putative homologue of Cdk1 (cdc2) in P. falciparum. We show that (i) PfPK5 is efficiently activated by heterologous (human) cyclin H and p25, a cyclin-like molecule that specifically activates human Cdk5; (ii) the activated enzyme can be inhibited by chemical Cdk inhibitors; (iii) Pfmrk, a putative P. falciparum homologue of the Cdk-activating kinase, does neither activate nor phosphorylate PfPK5; and (iv) PfPK5 is able to autophosphorylate in …

Go to article

Low Temperature, Postgrowth Self-Doping Of Cdte Single Crystals Due To Controlled Deviation From Stoichiometry, V. Lyahovitskaya, L. Chernyak, J. Greenberg, L. Kaplan, David Cahen Jan 2000

Low Temperature, Postgrowth Self-Doping Of Cdte Single Crystals Due To Controlled Deviation From Stoichiometry, V. Lyahovitskaya, L. Chernyak, J. Greenberg, L. Kaplan, David Cahen

Faculty Bibliography 2000s

Careful analysis of the Cd-Te pressure-temperature-composition phase diagram, shows a deviation of CdTe stoichiometry only in the Te-depletion direction between 450 and 550 degrees C. Combined control over the semiconductor composition, via intrinsic defects, and over the atmosphere and cooling rate can, therefore, yield a process for intrinsic doping of CdTe at these relatively low temperatures. We present results that support this. Quenching of CdTe, following its annealing in Te atmosphere at 400-550 degrees C, leads to p-type conductivity with a hole concentration of similar to 2 x 10(16) cm(-3). Slow cooling of the samples, after 550 degrees C annealing …

Go to article

All-Fiber Connectorized Compact Fiber Optic Delay-Line Modules Using Three-Dimensional Polarization Optics, Nicholas Madamopoulos, Nabeel A. Riza Jan 2000

All-Fiber Connectorized Compact Fiber Optic Delay-Line Modules Using Three-Dimensional Polarization Optics, Nicholas Madamopoulos, Nabeel A. Riza

Faculty Bibliography 2000s

Compact and all-fiber connectorized photonic delay-line modules based on three-dimensional bulk polarization optics are proposed and experimentally demonstrated. The modules are built on a single optical microbench and demonstrate optical leakage noise performance of -40 dB at switching speeds of 10 mu s. Insertion loss analysis is also performed. A special gradient-index lens fiber optic collimator design is proposed to further reduce the optical insertion loss of the delay-line module. A wavelength-dependent design is also proposed for expanding the applicability of the PDL module to multichannel operation.

Go to article

Single Axial-Mode Selection In A Far-Infrared P-Ge Laser, A. V. Muravjov, S. H. Withers, H. Weidner, R. C. Strijbos, S. G. Pavlov, V. N. Shastin, R. E. Peale Jan 2000

Single Axial-Mode Selection In A Far-Infrared P-Ge Laser, A. V. Muravjov, S. H. Withers, H. Weidner, R. C. Strijbos, S. G. Pavlov, V. N. Shastin, R. E. Peale

Faculty Bibliography 2000s

Single axial-mode operation of the pulsed far-infrared p-Ge laser with an intracavity Fabry-Perot type frequency selector has been observed by means of Fourier-transform spectroscopy. A spectral resolution better than 1 GHz has been achieved on an ordinary continuous-scan spectrometer using the event-locked technique for pulsed emission sources. A laser active-cavity finesse of at least unity has been directly confirmed from the measured emission spectral width. Analysis of the envelope of the corresponding interferogram suggests that the finesse exceeds 10.

Go to article

Relative Electrical Resistivities And Poling Of Nonlinear Optical Polymeric Waveguides, Tomáš Pliška, Joachim Meier, Arne Eckau, Vincent Ricci, Anne-Claire Le Duff, Michael Canva, George I. Stegeman, Paul Raymond, Francois Kajzar, Kwok Pong Chan Jan 2000

Relative Electrical Resistivities And Poling Of Nonlinear Optical Polymeric Waveguides, Tomáš Pliška, Joachim Meier, Arne Eckau, Vincent Ricci, Anne-Claire Le Duff, Michael Canva, George I. Stegeman, Paul Raymond, Francois Kajzar, Kwok Pong Chan

Faculty Bibliography 2000s

A method based on Maker fringe measurements of nonlinear optical coefficients has been used to determine the relative dc electrical resistivities of a series of linear and nonlinear optical polymers. The method can be used to identify low resistivity linear cladding materials for optimized electric field poling of nonlinear optical polymeric waveguides. As an example of the application of the technique we have studied the resistivity of poly(methyl methacrylate)-polystyrene (PMMA-PS) copolymers with varying content of the two components. The resistivity of PMMA was found to be one order of magnitude lower than that of PS.

Go to article

Evidence Of Scattering Anisotropy Effects On Boundary Conditions Of The Diffusion Equation, G. Popescu, C. Mujat, A. Dogariu Jan 2000

Evidence Of Scattering Anisotropy Effects On Boundary Conditions Of The Diffusion Equation, G. Popescu, C. Mujat, A. Dogariu

Faculty Bibliography 2000s

We present experimental evidence that the diffusion process close to the boundary is fundamentally different from the bulk diffusion in the sense that it is affected by the scattering properties of the individual centers. Systematic measurements show a nontrivial behavior of the extrapolation length ratio on the scattering anisotropy of individual particles. The results are compared with other works and are supported by an independent Monte Carlo simulation. A simple analytical model that emphasizes the influence of the last scattering event successfully describes the results.

Go to article

Comparison Of Infrared Frequency Selective Surfaces Fabricated By Direct-Write Electron-Beam And Bilayer Nanoimprint Lithographies, Irina Puscasu, G. Boreman, R. C. Tiberio, D. Spencer, R. R. Krchnavek Jan 2000

Comparison Of Infrared Frequency Selective Surfaces Fabricated By Direct-Write Electron-Beam And Bilayer Nanoimprint Lithographies, Irina Puscasu, G. Boreman, R. C. Tiberio, D. Spencer, R. R. Krchnavek

Faculty Bibliography 2000s

We report on the fabrication of crossed-dipole resonant filters by direct-write electron-beam and nanoimprint lithographies. Such structures have bean used as spectrally selective components at visible, microwave; and infrared wavelengths. Imprinting is accomplished in a modified commercial hot press at 155 degreesC. The replica is then etched in oxygen plasma and developed in chlorobenzene to selectively dissolve the poly(methylmethacrylate and methacrylic acid) and poly(methylmethacrylate) bilayer resist. This step enhances undercut and improves lift-off metalization. Infrared fourier transform spectroscopy was performed to characterize the transmission response of the frequency selective surfaces (FSSs) fabricated. The resonant behavior for the direct-write FSS was …

Go to article

Microwave Response Near Zero Magnetic Field In Transition-Metal-Doped Silicate Glasses, R. R. Rakhimov, H. R. Ries, D. E. Jones, L. B. Glebov, L. N. Glebova Jan 2000

Microwave Response Near Zero Magnetic Field In Transition-Metal-Doped Silicate Glasses, R. R. Rakhimov, H. R. Ries, D. E. Jones, L. B. Glebov, L. N. Glebova

Faculty Bibliography 2000s

A sharp microwave response centered at zero magnetic field was observed in manganese- and iron-doped Na2O-CaO-MgO-SiO2 glasses with phase opposite to the normal Mn+2 and Fe+3 paramagnetic signals. The response can be described as magneto-induced microwave conductivity in the dielectric glass that derives from spin-dependent charge migration within the first coordination sphere of the paramagnetic ion. In contrast to the spin-polarized tunneling in ferromagnets between different valence states of metals, the observed effect is due to spin-dependent tunneling that occurs in the vicinity of manganese or iron in diluted paramagnetic systems.

Go to article

Small-Tilt Micromirror-Device-Based Multiwavelength Three-Dimensional 2x2 Fiber Optic Switch Structures, Nabeel A. Riza, Sarun Sumriddetchkajorn Jan 2000

Small-Tilt Micromirror-Device-Based Multiwavelength Three-Dimensional 2x2 Fiber Optic Switch Structures, Nabeel A. Riza, Sarun Sumriddetchkajorn

Faculty Bibliography 2000s

Small-tilt micromirror-based 2x2 fiber optic switch array structures are proposed using fixed mirrors and fiber interconnections. A multiwavelength 2x2 fiber optic switch based on this small-tilt micromirror is experimentally demonstrated. The key innovation in this architecture is the use of a specially located fixed mirror to form a symmetric 2x2 retroreflective switching structure. These 2x2 fiber optic switch structures can also provide a fault-tolerant design using a macropixel approach. A two-dimensional digital micromirror device (2D-DMD) from Texas Instruments (TI) designed to operate in the visible band is used to represent the small-tilt micromirrors in our experimental demonstration. Multiwavelength switch operation …

Go to article

Wide-Angle, Off-Axis, See-Through Head-Mounted Display, Jannick P. Rolland Jan 2000

Wide-Angle, Off-Axis, See-Through Head-Mounted Display, Jannick P. Rolland

Faculty Bibliography 2000s

A 60-deg-field-of-view optical see-through head-mounted display (HMD) using off-axis optics has been designed for 3-D medical imaging visualization. Two basic on-axis optical design concepts for see-though HMDs are reviewed first, to motivate the design of an off-axis optical form. An off-axis design is then presented. Because HMDs are typically designed from the pupil of the eye to the miniature display, it is common to assess final performance according to the display characteristics. Such analysis, however, does not provide information that is easily translated into task-based performance metric. Therefore, we present an analysis of the performance of the design from a …

Go to article

Optical Versus Video See-Through Mead-Mounted Displays In Medical Visualization, Jannick P. Rolland, Henry Fuchs Jan 2000

Optical Versus Video See-Through Mead-Mounted Displays In Medical Visualization, Jannick P. Rolland, Henry Fuchs

Faculty Bibliography 2000s

We compare two technological approaches to augmented reality for 3-D medical visualization: optical and video see-through devices. We provide a context to discuss the technology by reviewing several medical applications of augmented-reality research efforts driven by real needs in the medical field, both in the United States and in Europe. We then discuss the issues for each approach, optical versus video, from both a technology and human-factor point of view. Finally, we point to potentially promising future developments of such devices including eye tracking and multifocus planes capabilities, as well as hybrid optical/video technology.

Go to article

Fast Algorithms For Histogram Matching: Application To Texture Synthesis, J. P. Rolland, V. Vo, B. Bloss, C. K. Abbey Jan 2000

Fast Algorithms For Histogram Matching: Application To Texture Synthesis, J. P. Rolland, V. Vo, B. Bloss, C. K. Abbey

Faculty Bibliography 2000s

Texture synthesis is the ability to create ensembles of images of similar structures from sample textures that have been photographed. The method we employ for texture synthesis is based on histogram matching of images at multiple scales and orientations. This paper reports two fast and in one case simple algorithms for histogram matching We show that the sort-matching and the optimal cumulative distribution function (CDF)-matching (OCM) algorithms provide high computational speed compared to that provided by the conventional approach. The sort-matching algorithm also provides exact histogram matching. Results of texture synthesis using either method show no subjective perceptual differences. The …

Go to article

Oxidation And Chemical State Analysis Of Polycrystalline Magnetron Sputtered (Ti,Al)N Films At Ambient And Liquid N-2 Temperatures, S. Seal, A. Kale, K. B. Sundaram, D. Jimenez Jan 2000

Oxidation And Chemical State Analysis Of Polycrystalline Magnetron Sputtered (Ti,Al)N Films At Ambient And Liquid N-2 Temperatures, S. Seal, A. Kale, K. B. Sundaram, D. Jimenez

Faculty Bibliography 2000s

In order to improve the functional properties of hard coatings, recent investigations have been directed towards Ti-N based multicomponent materials. The nitride (Ti, Al)N, in particular, with a Ti:Al ratio of 1:1 seems to be a promising alternative to the widely used TiN, exhibits better oxidation resistance and hence improved performance over that of TiN. (Ti, Al)N coatings were de sputter deposited onto 316SS substrates under ambient and liquid nitrogen temperatures. As deposited films were oxidized in a vertical fused-silica tube furnace in pure O-2 flowing atmosphere at temperatures ranging from 700 to 900 degrees C. Scanning electron microscope and …

Go to article

Systems Engineering Analysis Of Aplanatic Wolter Type I X-Ray Telescopes, Patrick L. Thompson, James E. Harvey Jan 2000

Systems Engineering Analysis Of Aplanatic Wolter Type I X-Ray Telescopes, Patrick L. Thompson, James E. Harvey

Faculty Bibliography 2000s

It is well known that normal-incidence aplanatic telescope designs perform better at small field angles than ones corrected only for spherical aberration. This is why most large astronomical telescopes fabricated in the past fifty years have been of the Ritchey-Chretien (aplanatic) design rather than of the classical Cassegrain design. For the relatively new field of x-ray astronomy, the Welter type I grazing incidence design has been extensively utilized. It consists of a paraboloidal primary mirror coaxial with a confocal hyperboloidal secondary mirror. Aplanatic versions of the Welter type I grazing incidence x-ray telescope have been discussed in detail in the …

Go to article

First Prev Next Last