The paper proposes finite state model based current control of a three-level neutral point clamped (NPC) five-phase voltage source inverter. The space vector model of a five-phase voltage source inverter (VSI) yield 2...
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The paper proposes finite state model based current control of a three-level neutral point clamped (NPC) five-phase voltage source inverter. The space vector model of a five-phase voltage source inverter (VSI) yield 243 space vectors, with 240 active and three zero vectors. The presented technique utilizes only 21 space vectors for the current control and hence the name finite state is given. Search is made by the algorithm to find the vector which minimizes the chosen cost function. The performance of the current control heavily depends upon the choice of the cost function, the number of vectors used and the sampling time. The developed technique is tested for RLE load using simulation approach. The proposed technique offers very good capacitor voltage balancing and offers high performance results in terms of current distortion. The technique is very useful for real time implementation due to a small number of vectors being used in contrary to space vector PWM where at least 43 vectors are required to obtain similar results. Simulation results are given in the this submission, while the experimental validation of the concept will be provided in the final paper.
Virtual and augmented reality environments have been adopted in medicine as a means to enhance the clinician's view of the anatomy and facilitate the performance of minimally invasive procedures. Their value is tr...
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Artificial Immune Systems (AISs) are composed of techniques inspired by immunology. The clonal selection principle ensures the organism adaptation to fight invading antigens by an immune response activated by the bind...
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Artificial Immune Systems (AISs) are composed of techniques inspired by immunology. The clonal selection principle ensures the organism adaptation to fight invading antigens by an immune response activated by the binding of antigens and antibodies. As an immune response can be elicited even when the binding between an antigen and an antibody is not perfect, an approximate binding might suffice, and a Fuzzy Logic mechanism might be the most appropriate mechanism to control such process. This paper presents a novel hybrid model based on concepts of Immune and Fuzzy Systems with applications to pattern recognition problems. The preliminary results obtained here suggest the proposed model is a promising pattern recognition tool.
In this work, a fully implantable and scalable neuroprocessor has been designed to process neural recordings in awake behaving animals. The neuroprocessor operates at 6.4 MHz to process neural signals from 32 microele...
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In this work, a fully implantable and scalable neuroprocessor has been designed to process neural recordings in awake behaving animals. The neuroprocessor operates at 6.4 MHz to process neural signals from 32 microelectrode channels sampled at 25 KHz and transmits only the critical neural information over a 1 Mbps wireless channel in order to meet the stringent hardware and communication constraints imposed on an implantable device. The neuroprocessor can be program.ed to compress neural data using a sparse representation of neural signals via lifting discrete wavelet transform (DWT) and/or perform on-the-fly spike sorting on the compressed data stream if followed by a “smart” thresholding mechanism. This unique feature reduces the overall system latency and permit instantaneous decoding of neural signals to take place in real-time. The neuroprocessor therefore uses the limited telemetry bandwidth more efficiently while preserving important information in the neural data, and hence improves the practicality and viability of implantable microelectrode arrays to accelerate their deployment in clinical applications of brain-machine interfaces.
Devices for continuous glucose monitoring (CGM) are currently a major focus of research in the area of diabetes management. It is envisioned that such devices will have the ability to alert a diabetes patient (or the ...
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There remains considerable interest in the behavior of acceptors in ZnO, the ultimate goal being the realization of device grade p-type material. Silver is a candidate acceptor, and, in this study, in situ doping of s...
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In this paper, we investigate a dual-hop decode-and-forward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our stud...
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In this paper, we investigate a dual-hop decode-and-forward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our study, we derive exact closed-form expression for the outage probability based on the exact statistics of each hop. Furthermore, we perform asymptotic analysis and we deduce the diversity order of the scheme. We validate our analysis by showing that performance simulation results coincide with our analytical results over different network architectures.
K562 mammalian cells are sorted using a highly integrated microfabricated fluorescence-activated cell sorter (∝FACS). The sample cells are purified with an enrichment factor of 230 at a high throughput (>1,000 cel...
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K562 mammalian cells are sorted using a highly integrated microfabricated fluorescence-activated cell sorter (∝FACS). The sample cells are purified with an enrichment factor of 230 at a high throughput (>1,000 cells/sec).
Microwave, x-ray, and radio-frequency radiation sources require a cathode emitting electrons into vacuum. Thermionic B-type dispenser cathodes consist of BaxOz coatings on tungsten (W), where the surface coatings lowe...
Microwave, x-ray, and radio-frequency radiation sources require a cathode emitting electrons into vacuum. Thermionic B-type dispenser cathodes consist of BaxOz coatings on tungsten (W), where the surface coatings lower the W work function and enhance electron emission. The new and promising class of scandate cathodes modifies the B-type surface through inclusion of Sc, and their superior emissive properties are also believed to stem from the formation of a low work function surface alloy. In order to better understand these cathode systems, density-functional theory (DFT)-based ab initio modeling is used to explore the stability and work function of BaxScyOz on W(001) monolayer-type surface structures. It is demonstrated how surface depolarization effects can be calculated easily using ab initio calculations and fitted to an analytic depolarization equation. This approach enables the rapid extraction of the complete depolarization curve (work function versus coverage relation) from relatively few DFT calculations, useful for understanding and characterizing the emitting properties of novel cathode materials. It is generally believed that the B-type cathode has some concentration of Ba-O dimers on the W surface, although their structure is not known. Calculations suggest that tilted Ba-O dimers are the stable dimer surface configuration and can explain the observed work function reduction corresponding to various dimer coverages. Tilted Ba-O dimers represent a new surface coating structure not previously proposed for the activated B-type cathode. The thermodynamically stable phase of Ba and O on the W surface was identified to be the Ba0.25O configuration, possessing a significantly lower Φ value than any of the Ba-O dimer configurations investigated. The identification of a more stable Ba0.25O phase implies that if Ba-O dimers cover the surface of emitting B-type cathodes, then a nonequilibrium steady state must dominate the emitting surface. The identification of a
Photonic crystal cavities with tunable surface area via multiple-hole defects were investigated for increased resonance wavelength shins upon exposure to variable-index analytes. Sensitivity was improved by 10% compar...
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