A theoretical model of microwave absorption in linear dielectric (non-ferroelectric) ionic crystals that takes into account the presence of point defects was synthesized and verified using NaCl single crystals. In the...
A theoretical model of microwave absorption in linear dielectric (non-ferroelectric) ionic crystals that takes into account the presence of point defects was synthesized and verified using NaCl single crystals. In the next stage of this research, we will introduce a controlled density of dislocations into the single crystal NaCl samples and study the effect on the microwave absorption mechanisms (ionic conduction, dielectric relaxation and multi-phonon processes) both theoretically and experimentally. Qualitative outlines of this modified theory are presented. The loss factor ε’ has been measured in the dislocation-free case by a cavity resonator insertion technique and the experimental results are in good agreement with the theoretical model. We describe the sample preparation technique that will be used to produce a controlled dislocation density in single crystal samples that will also be studied in our cavity resonator insertion system.
The mortality related to cervical cancer can be substantially reduced through early detection and treatment. However, current detection techniques, such as Pap smear and colposcopy, fail to achieve a concurrently high...
The mortality related to cervical cancer can be substantially reduced through early detection and treatment. However, current detection techniques, such as Pap smear and colposcopy, fail to achieve a concurrently high sensitivity and specificity. In vivo fluorescence spectroscopy is a technique which quickly, noninvasively and quantitatively probes the biochemical and morphological changes that occur in pre-cancerous tissue. RBF ensemble algorithms based on such spectra provide automated, and near realtime implementation of pre-cancer detection in the hands of nonexperts. The results are more reliable, direct and accurate than those achieved by either human experts or multivariate statistical algorithms.
Body surface Laplacian maps were studied from a set of unipolar potential data in healthy human subjects. The present results indicate that body surface Laplacian maps can be obtained with high reproducibility in the ...
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Body surface Laplacian maps were studied from a set of unipolar potential data in healthy human subjects. The present results indicate that body surface Laplacian maps can be obtained with high reproducibility in the human subjects studied, and can reveal detailed information regarding the underlying ventricular conduction process.
The authors have developed a multi-purpose X-window based mapping software system. This software system can be used to analyze and display body surface maps of the Laplacian electrocardiogram, potential electrocardiog...
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The authors have developed a multi-purpose X-window based mapping software system. This software system can be used to analyze and display body surface maps of the Laplacian electrocardiogram, potential electrocardiogram, electroencephalogram, etc.
Estimation of the distortion parameters in pattern recognition applications is addressed. This paper reports a new technique for the estimation of distortion parameters using correlation techniques with a synthetic jo...
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Estimation of the distortion parameters in pattern recognition applications is addressed. This paper reports a new technique for the estimation of distortion parameters using correlation techniques with a synthetic joint Fourier transform (JFT) correlator set-up. In particular, the degree of rotational distortion is studied with the synthesis of a composite estimation feature from a set of distorted targets. Simulation results are presented to show better estimation performance.
Processing conditions such as temperature, soak time, and heating rate affect the final density of conventionally-sintered and microwave-sintered ceramics. Of additional importance is the question of whether microwave...
Processing conditions such as temperature, soak time, and heating rate affect the final density of conventionally-sintered and microwave-sintered ceramics. Of additional importance is the question of whether microwave-sintered ceramics display intrinsically superior macroscopic engineering properties compared with conventionally-sintered control specimens. An analysis using the Yates algorithm indicates that the processing condition which has the largest impact on the density of the specimen is the heating method (microwave vs. conventional). The microwave-sintered specimens resulted in higher densities and higher fracture strengths. However, it was determined that the higher fracture strengths were due to the higher sintered densities rather than a significantly different microstructure.
Fusion is one of a few future power sources with the potential to be both economically acceptable and have attractive safety and environmental characteristics. In addition fusion fuel is inexhaustible, readily availab...
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Fusion is one of a few future power sources with the potential to be both economically acceptable and have attractive safety and environmental characteristics. In addition fusion fuel is inexhaustible, readily available, and affordable. Fusion can be an important option in the energy mix for the future because of environmental, supply, and political difficulties associated with fossil fuels and present-day nuclear power. An overview of the technological requirements for fusion power plants is given and their economic, safety, and environmental features are explored. Conceptual design studies predict that fusion power plants will be capital intensive and will be used as central electric power station. The cost of electricity from these power stations is estimated be comparable to other sources of energy. In addition, by using "low-activation" materials and care in design, fusion safety and environmental advantages (with respect to consequences of accidents, waste-disposal, and air pollution, etc.) can be realized. These advantages of fusion will not, however, be achieved automatically and a significant science and technology development program will be required for their realization.
An analytic model for the performance evaluation of space-division asynchronous transfer mode (ATM) switches is presented. This model assumes that the switch has a fixed capacity of m, where 1/spl les/m/spl les/N (N i...
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An analytic model for the performance evaluation of space-division asynchronous transfer mode (ATM) switches is presented. This model assumes that the switch has a fixed capacity of m, where 1/spl les/m/spl les/N (N is the number of trunks). Other important parameters include arrival rate and buffer sizes. Numerical solutions for the maximum throughput, cell delay, and cell loss probability are given with simulation being utilized in order to validate the analytic model. For independent and identical Bernoulli arrivals, the study shows that the contention processes can be modeled as discrete M/D/m (FIFO or Random) queues, while input queues can be modeled by Geom/G/1 queues, and the output queues are G/sup [X]//D/1 queues. A closed-form approximation for cell delay when m>2 is given. The result shows that the performance of switches with a small capacity can approach that of output queueing. The model and result can be used for switch design analysis and higher layer performance models.
We present a comparative analysis of bandwidth access control schemes under nonstationary traffic conditions for heterogeneous circuit-mode traffic offered to a B-ISDN network link. A unified model for analysing the b...
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We present a comparative analysis of bandwidth access control schemes under nonstationary traffic conditions for heterogeneous circuit-mode traffic offered to a B-ISDN network link. A unified model for analysing the behavior of several bandwidth access control schemes is developed using a Markov process model with acceptance functions. Numerical techniques are used to solve the associated Chapman-Kolmogorov equations and determine the nonstationary behavior. Performance results are given for several common bandwidth access control schemes, namely: complete sharing, complete partitioning, partial sharing, classical trunk reservation, and the probabilistic reservation policy. It is shown that the use of the average arrival rate to estimate the average connection blocking rate may be an underestimate for a system with a time varying arrival process. Also, it is found that a nonstationarity in one traffic class arrival process can impact other stationary traffic classes and the degree of variability depends on the particular access control scheme.
Fiber optic oblique incidence reflectometry has been demonstrated to be a simple and accurate method for measuring the optical properties, μa and μs', of turbid media such as biological tissues [1,2]. After samp...
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