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EXTENDING THE RANGE OF PCM/FM USING A MULTISYMBOL DETECTOR AND TURBO CODINGGeoghegan, Mark 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / It has been shown that a multi-symbol detector can improve the detection efficiency of PCM/FM by 3 dB when compared to traditional methods without any change to the transmitted waveform. Although this is a significant breakthrough, further improvements are possible with the addition of Forward Error Correction (FEC). Systematic redundancy can be added by encoding the source data prior to the modulation process, thereby allowing channel errors to be corrected using a decoding circuit. Better detection efficiency translates into additional link margin that can be used to extend the operating range, support higher data throughput, or significantly improve the quality of the received data. This paper investigates the detection efficiency that can be achieved using a multisymbol detector and turbo product coding. The results show that this combination can improve the detection performance by nearly 9 dB relative to conventional PCM/FM systems. The increase in link margin is gained at the expense of a small increase in bandwidth and the additional complexity of the encoding and decoding circuitry.
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Giant Short-Faced Bears (Arctodus Simus) in Pleistocene Florida USA, a Substantial Range ExtensionSchubert, Blaine W., Hulbert, Richard C., MacFadden, Bruce J., Searle, Michael, Searle, Seina 01 January 2010 (has links)
Fossils of the giant short-faced bear, Arctodus simus (Cope, 1879), have been recovered from over 100 localities in North America, extending from Mexico to Alaska and California to Virginia. Despite this large range, the species has never been recorded from the southeastern United States. The lesser short-faced bear, Arctodus pristinus Leidy, 1854 is well represented from this region, particularly Florida, but all known occurrences are late Pliocene middle Pleistocene in age (about 2.5 to 0.3 Ma). Differentiating A. simus from A. pristinus can be difficult because large individuals of A. pristinus overlap in size with small individuals of A. simus, and there are few morphological differences. However, these two taxa can be clearly separated based on the relative proportions of their molars and premolars. Two Pleistocene records of A. simus representing a minimum of three individuals from the Withlacoochee River drainage of central Florida are reported here, substantially extending the distribution of this massive bear into southeastern North America. A late Pleistocene age for these occurrences is corroborated by an associated Rancholabrean fauna and rare earth elemental analyses. One of the reported individuals is quite large, supporting the hypothesis of extreme sexual dimorphism in A. simus and rejecting a hypothesis of two subspecies.
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Modeling and Implementation of a Hardware Efficient Low-Voltage-To-Cell Battery Balancing Circuit for Electric Vehicle Range Extension / Low-Voltage-To-Cell Battery Balancing CircuitRiczu, Christina January 2020 (has links)
Modeling and Implementation of a Hardware Efficient Low-Voltage-To-Cell Battery Balancing Circuit for Electric Vehicle Range Extension / One disadvantage of electric vehicles is their limited driving range when compared to internal combustion engine vehicles. Battery packs are also a significant cost to electric vehicle manufacturers, and lithium-ion battery cells must remain within controlled voltage limits. Thus, the requirements for the electric system are to be cost effective, perform battery management, and make it as efficient as possible to increase its range.
Battery packs are typically constructed from around 100 battery cells in a series connection. During use of an electric vehicle, the battery cells become mismatched due to small differences in capacity. This effect is further amplified as the electric vehicle ages. Diverging cells cause issues during driving, since weak cells can limit the useable capacity of the vehicle. In order to use the whole capacity of the battery pack, and thus the entire range of the electric vehicle, the cells should be balanced. Strong cells should distribute their excess capacity to weaker cells during driving.
The thesis presents the design, modeling and implementation of a novel hardware-efficient battery balancing circuit. First, the theory behind battery balancing is presented. Next, existing battery balancing circuits are compared. Finally, the proposed battery balancing circuit is discussed. The design of the proposed topology is examined in detail. Simulations show that the circuit transfers energy between non-adjacent cells throughout the entire pack. Experimental work is performed on two custom printed circuit boards, a 12 cell lithium-ion module, and a 12V lead acid battery. The results confirm the function of the prototype.
The effect of the battery balancing circuit on driving range is examined with vehicle modeling simulations. A 2018 Chevrolet Bolt model is produced and capacity differences are given to each cell. The proposed topology balances the cells while driving, extending driving range on UDDS and HWFET drive cycles. / Thesis / Master of Applied Science (MASc) / One disadvantage of electric vehicles is their limited driving range when compared to internal combustion engine vehicles. Thus, there is a requirement to make the electric system as efficient as possible in order to increase its range. A large piece of the electric system includes the battery pack. Battery packs are typically constructed from around 100 battery cells in a series connection. During use of an electric vehicle, the battery cells become mismatched. This effect is also amplified as the electric vehicle ages. In order to use the whole capacity of the battery pack, and thus the entire range of the electric vehicle, the cells should be balanced. The thesis presents the design, modeling and implementation of a novel hardware efficient battery balancing circuit. The effect of the battery balancing circuit on driving range is examined.
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Miniaturizace a zvýšení dosahu modulu W-DMX v1.0 / Miniaturization and Range Extension of W-DMX v1.0 ModuleRojček, Martin January 2010 (has links)
The aim of this master thesis is to design a wireless system which would be primarily used for a control of stage lighting. Our idea is to establish wireless links, that will carry DMX512 protocol, between individual lighting devices based on wireless transceiver nRF2401A. The foundation of our project comes from a previous design, which was not completely suitable for a practical use because of its rather large proportions and a short RF range. The project resolves the issue of relatively short range coverage through the deployment of RF amplifier RF5722. In the same tme, it also takes into account other technical aspects such as the use of antenas with a higher gain, front-end circuits or increased transmission reliability through frequency hopping scheme. Proper attention is also given to a minimalization of the module dimensions by using SMD components and layout adjustements, so it would be possible to place the whole board inside XLR connector. Set of printed circuit boards with the specified characteristics, which is the expected outcome of our project, were designed with Eagle PCB design environment.
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Structural Analysis of Rock Canyon Near Provo, UtahWald, Laura Cardon 15 March 2007 (has links) (PDF)
A detailed structural study of Rock Canyon (near Provo, Utah) provides insight into Wasatch Range tectonics and fold-thrust belt kinematics. Excellent exposures along the E-W trending canyon allow the use of digital photography in conjunction with traditional field methods for a thorough analysis of Rock Canyon's structural features. Detailed photomontages and geometric and kinematic analyses of some structural features help to pinpoint deformation mechanisms active during the canyon's tectonic history. Large-scale images and these structural data are synthesized in a balanced cross section, which is used to reconstruct the structural evolution of this portion of the range. Projection of surficial features into the subsurface produces geometrical relationships that correlate well with a fault-bend fold model involving one or more subsurface imbrications. Kinematic data (e.g. slickenlines, fractures, fold axes) indicate that the maximum stress direction during formation of the fault-bend fold trended at approximately 120°. Following initial thrusting, uplift and development of a thrust splay produced by duplexing may have caused a shift in local stresses in the forelimb of the Rock Canyon anticline leading to late-stage normal faulting during Sevier compression. These normal faults may have activated deformed zones previously caused by Sevier folding, and reactivated early-stage decollements found in the folded weak shale units and shaly limestones. Movement on most of these normal faults roughly parallels stress directions found during initial thrusting indicating that these extensional features may be coeval with thrusting. Other zones of extension and brittle failure produced by lower ramp geometry appear to have been activated during Tertiary Basin and Range extension along the Wasatch Fault Zone. Slickenline data on these later normal faults suggest a transport direction of nearly E-W distinguishing it from earlier events.
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