114,513 research outputs found
Letter from A. F. Potter to John H. Page
No full textLetter from A. F. Potter to John H. Page referring his request to build a railway to the District Forester at Albuquerque, New Mexico
Distributed H∞-consensus filtering for target state tracking over a wireless filter network with switching topology, channel fading and packet dropouts
No full textThis paper is concerned with the problem of distributed H∞-consensus filtering for target state tracking over a wireless filter network. The wireless filter network consists of a large number of filter nodes. The network topology is supposed to be switching or changeable over time. Data communication between filter nodes is subject to some network-induced constraints including packet dropouts and channel fading. Different from some existing results, packet dropouts and channel fading are assumed to occur not only in the measurement process for sensors but also in the transmission process among filter nodes. Within such settings, a distributed H∞-consensus filtering method is developed to ensure both the estimation accuracy of filters and the robustness of the filtering error system against network-induced constraints. Criteria on designing desired distributed H∞ consensus-based filter are derived in terms of a set of linear matrix inequalities. Numerical examples are given to verify the effectiveness of the proposed target state tracking filtering algorithm.Full Tex
Polly H. Carder Collection on George F. Root
No full textGeorge Frederick Root (1820-1895) was an American songwriter and music educator. He is perhaps best known for his song "The Battle Cry of Freedom," which was written and rose to popularity during the U.S. Civil War. The Polly H. Carder Collection on George F. Root contains original published scores and songbooks from the period 1852-1907 and photocopied scores collected by Polly H. Carder, author of the book George F. Root, Civil War Songwriter: A Biography. The collection also contains a short article, "The Last Days of George F. Root," written by Root's daughter, Clara Louise Burnham
Mixed H2/H∞ filtering for uncertain systems with regional pole assignment
No full textCopyright [2005] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.The mixed H2/H∞ filtering problem for uncertain linear continuous-time systems with regional pole assignment is considered. The purpose of the problem is to design an uncertainty-independent filter such that, for all admissible parameter uncertainties, the following filtering requirements are simultaneously satisfied: 1) the filtering process is asymptotically stable; 2) the poles of the filtering matrix are located inside a prescribed region that compasses the vertical strips, horizontal strips, disks, or conic sectors; 3) both the H2 norm and the H∞ norm on the respective transfer functions are not more than the specified upper bound constraints. We establish a general framework to solve the addressed multiobjective filtering problem completely. In particular, we derive necessary and sufficient conditions for the solvability of the problem in terms of a set of feasible linear matrix inequalities (LMIs). An illustrative example is given to illustrate the design procedures and performances of the proposed method
Quench characteristics of a Cu-Stabilized 2G HTS conductor
No full textThe prospect of medium/high field superconducting magnets using 2G HTS tapes is approaching to reality with continued enhancement in the performance of these conductors. Direct measurements of 1d adiabatic quench initiation and propagation of a Cu-stabilized 2G conductor have been carried out with spatial-temporal recording of temperature and voltage following the deposition of various local heat pulses to the conductor at different temperatures between 40K and 64K carrying different transport currents. It was found that the stabilizer-free 2G tape maintains the unique characteristics previously measured in non-stabilized tape of increasing MPZ with transport current and higher quench energy at lower temperatures. The minimum quench energy, minimum propagation zone (MPZ) length are determined as a function of temperature and transport current. The change in MPZ size is investigated with measured temperature dependent E-J characteristics. The results add more detail to help understand the unique characteristics of increasing MPZ with transport current and lower temperatures
Ruthenium-Catalyzed C–H Oxygenation on Aryl Weinreb Amides
No full textVersatile ruthenium catalysts enabled unprecedented C-H bond oxygenations of aryl Weinreb amides with ample scope under exceedingly mild reaction conditions, thereby also giving access to valuable ortho-hydroxylated aldehydes. Mechanistic studies provided strong support for a kinetically relevant C-H bond activation
Production of xylooligosaccharides from xylans by extracellular xylanases from Thermobifida fusca
No full textContribution of Information and Communication Technology (ICT) in Country’S H-Index
No full textThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear
Distributed H∞-consensus fault detection for fuzzy systems with faults, switching network topology, packet dropouts and channel fading
No full textThis paper is concerned with the distributed H∞-consensus fault detection (FD) filtering problem for a class of discrete-time Takagi-Sugeno (T-S) fuzzy systems with faults, switching network topology, channel fading and different communication channels-induced packet dropouts with different missing rates. The purpose of the addressed problem is to design a distributed H∞-consensus FD filter to guarantee the sensitivity of the residual signal to the faults and the robustness of the residual system to effects of both switching network topology, channel fading and different communication channels-induced packet dropouts with different lossing rates. On the basis of the T-S fuzzy approach and the Lyapunov functional, distributed H∞-consensus FD filter design criterion is derived such that the residual system is exponentially stable in the mean square, and the optimal H∞ filtering performance index is derived. A simulation example is conducted to verify the usefulness of the proposed FD filter design approach.No Full Tex
Downlink Space–Time Spreading Using Interference Rejection Codes
No full textIn this paper, the authors will investigate the performance of a loosely synchronized (LS) code-based space–time spreading (STS) scheme in comparison to that of classic Walsh code and pseudonoise code-based STS when communicating over dispersive Nakagami-m multipath channels. Closed-form formulas are derived for characterizing the bit-error-rate performance as a function of the number of resolvable paths L and the number of users K. Our numerical results suggest that the employment of LS code-based STS scheme is beneficial in a low-user-load and low-dispersion channel scenario, where a near-single-user performance can be achieved without a multiuser detector. Index Terms—Code-division multiple access (CDMA), Gaussian approximation, interference-free window (IFW), large area synchronized (LAS) codes, loosely synchronized (LS) codes, Nakagami-m fading
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