The Signal Processing Instructional Facility (SPIF Lab) is an experiment in using in interactive multimedia for teaching concepts related to linear systems theory and signal processing. The goals of the SPIF lab are t...
The Signal Processing Instructional Facility (SPIF Lab) is an experiment in using in interactive multimedia for teaching concepts related to linear systems theory and signal processing. The goals of the SPIF lab are to augment, enhance, and interconnect sophomore, junior, and senior level courses with the common thread of linear systems and transforms by unifying the experimentation medium. In this fashion, physical phenomenon is returned to the forefront of engineering education. The laboratory features powerful Mathematica Notebooks (a form of hypertext) and interactive applications that use dedicated DSP microprocessors.
The benefits of separating the simulation of a physical system from the decision-making process are discussed. A formal model for the interface between such a simulation and a knowledge-based manager is presented. The...
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This paper describes an interconnect technology used for high density multichip systems. The process involves the electroplating of through-holes in silicon (Si) substrates. These metallized holes act as interconnects...
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The growth of high quality Si/GaAs superlattices on GaAs substrates using molecular beam epitaxy is described. A typical superlattice structure consisted of ten periods of thin (<5Å) layers of pseudomorphic si...
The growth of high quality Si/GaAs superlattices on GaAs substrates using molecular beam epitaxy is described. A typical superlattice structure consisted of ten periods of thin (<5Å) layers of pseudomorphic silicon alternating with thick GaAs layers; typical GaAs thicknesses range from 100Å to 1850Å. In situ reflection high energy electron diffraction analysis of the structures during growth showed the silicon layers developed a (3 × 1) reconstruction, while the GaAs exhibited a (4×)→(3×)→(3×1)→(2×4) reconstruction sequence. Both observations agree with prior studies of the growth of embedded silicon in GaAs/Si/GaAs heterostructures. X-ray diffraction using the (004) reflection showed sharp and intense satellite peaks (out to 22 orders in one case), indicating a high level of structural quality. Very good agreement has been obtained between observed diffraction patterns and those calculated via dynamical simulation.
Reports of enhanced sintering rates associated with microwave heating may be due to nonthermal lattice fluctuation statistics. Recent theoretical analyses reviewed in this paper confirm the feasibility of this phenome...
Reports of enhanced sintering rates associated with microwave heating may be due to nonthermal lattice fluctuation statistics. Recent theoretical analyses reviewed in this paper confirm the feasibility of this phenomenon for a wide variety of situations involving very different microwave absorption mechanisms. For materials with weak microwave absorption coefficients, the effect is expected to be uniformly distributed throughout the volume. For strongly absorbing materials, however, the effect is expected to be concentrated near the material surface, with a characteristic exponential penetration depth of Lnt ∼ 10 − 100 μm. An “observable” nonthermal effect depends on the relative magnitude of the microwave electric field strength ¦E¦ and the lattice ion energy relaxation rate γ with the most pronounced effects occurring for larger values of ¦E¦ and smaller values of γ.
Electric poling at field intensities approaching the dielectric strength of the film is possible with corona poling. Polymeric thin films with large second-order nonlinearities can be created with this poling techniqu...
Electric poling at field intensities approaching the dielectric strength of the film is possible with corona poling. Polymeric thin films with large second-order nonlinearities can be created with this poling technique. In this paper, the corona poling of nonlinear polymeric films at elevated temperatures, processing, characterization and possible ultrashort-pulse applications are reviewed. An experimental technique is presented to measure the electric field during poling of the nonlinear polymeric film. The characterization of orientational order in corona-poled nonlinear polymeric films and the effects associated with the large electric field during poling are discussed. Poled polymeric thin films are uniquely suited for second-order nonlinear optical applications of ultrashort pulses (< 50 fsec) since minimal pulse spreading occurs. The sum-frequency ultrashort-pulse application of nonlinear polymeric thin films and limitations of the thin polymeric films are discussed. Experimental results are presented of a side-chain nonlinear polymer that is ideally suited for ultrashort-pulse applications.
Polar solvents, including dimethylformamide (DMF), have been investigated as anticancer drugs. Their potential usefulness is constrained by hepatotoxic effects. The ability to enhance drug cytotoxicity with ultrasound...
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This paper proposes a new ID-based cryptographic scheme for implementing public-key cryptosystems and signatures. Instead of generating and publishing a public key for each user, the ID-based scheme permits each user ...
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Data acquired for object reproduction by laser or stereovision scanning processes are often over-determined. This causes problems in manufacturing processes, for example, NC tool path generation. Data reduction is a s...
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Data acquired for object reproduction by laser or stereovision scanning processes are often over-determined. This causes problems in manufacturing processes, for example, NC tool path generation. Data reduction is a sensible solution to such problems. A heuristic method to reduce the data points with the user given tolerance is presented.
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