Similar to a recent paper by Karczub [J. Acoust. Soc. Am., Vol. 119(6), 3553‐3557, 2006], this work utilizes a symbolic math solution to obtain analytical solutions for the dispersion relation in a thin circular cyli...
Similar to a recent paper by Karczub [J. Acoust. Soc. Am., Vol. 119(6), 3553‐3557, 2006], this work utilizes a symbolic math solution to obtain analytical solutions for the dispersion relation in a thin circular cylindrical shell. Analyses on the propagating wave mode shapes are particularly emphasized. The analytical solutions provide a straightforward calculation for all four branches of the dispersion curves, and the cumbersome numerical root searching technique is avoided. The dispersion relations for the breathing and torsional modes (n=0 circular harmonic), which were neglected by Karczub, are included. Mode shapes that characterize the types of wave that are predominantly transversal, longitudinal, circumferential, or in any combination of the three are analyzed in considerable detail. Effects by thickness and Poisson ratio variations are considered and examined. The cutoff frequencies for the higher order propagating modes are compared among the various orders of circular harmonics, from n = 0 to 10. Finally, comparison among several shell theories in the dispersion relation prospective, which is directly related to their accuracy in predicting the vibratory resonant frequencies of a finite shell, is also included in the discussion.
This paper presents a decentralized infrastructure, called Web2Peer, which makes Web pages available on Internet through P2P networks. Different from the conventional Web, the proposed approach does not need, for inst...
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This paper presents a decentralized infrastructure, called Web2Peer, which makes Web pages available on Internet through P2P networks. Different from the conventional Web, the proposed approach does not need, for instance, a HTTP address or a central Web Server. Web2Peer provides a set of functions for publishing, locating, and replicating Web pages on Internet ensuring high availability and fault tolerance. Our infrastructure allows anyone who has a computer connected to the Internet, even through a domestic ADSL connection, to publish Web pages through their own machines without any additional cost
This paper evaluates how well a significant number of broadcasting protocols for MANETs behave when under a realistic scenario of momentary failures and topology changes, which is represented by an omission fault mode...
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This paper evaluates how well a significant number of broadcasting protocols for MANETs behave when under a realistic scenario of momentary failures and topology changes, which is represented by an omission fault model. Reliable protocols which use additional mechanisms to ensure higher delivery rates beyond best- effort guarantees - have been proposed, but they exhibit unacceptably high end-to-end delays. As a result of the study conducted, a new mechanism that helps to enhance the reliability of deterministic broadcasting protocols is proposed. The mechanism allows for scalability, and is capable of ensuring good delivery rates (in spite of failures) while maintaining lower end-to-end delays. Simulation results demonstrate the efficacy of the mechanism.
Chemical reaction networks by which individual cells gather and process information about their chemical environments have been dubbed "signal transduction" networks. Despite this suggestive terminology, the...
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ISBN:
(纸本)9780262195683
Chemical reaction networks by which individual cells gather and process information about their chemical environments have been dubbed "signal transduction" networks. Despite this suggestive terminology, there have been few attempts to analyze chemical signaling systems with the quantitative tools of information theory. Gradient sensing in the social amoeba Dictyostelium discoideum is a well characterized signal transduction system in which a cell estimates the direction of a source of diffusing chemoattractant molecules based on the spatiotemporal sequence of ligand-receptor binding events at the cell membrane. Using Monte Carlo techniques (MCell) we construct a simulation in which a collection of individual ligand particles undergoing Brownian diffusion in a three-dimensional volume interact with receptors on the surface of a static amoeboid cell. Adapting a method for estimation of spike train entropies described by Victor (originally due to Kozachenko and Leonenko), we estimate lower bounds on the mutual information between the transmitted signal (direction of ligand source) and the received signal (spatiotemporal pattern of receptor binding/unbinding events). Hence we provide a quantitative framework for addressing the question: how much could the cell know, and when could it know it? We show that the time course of the mutual information between the cell's surface receptors and the (unknown) gradient direction is consistent with experimentally measured cellular response times. We find that the acquisition of directional information depends strongly on the time constant at which the intracellular response is filtered.
Faculty members from Georgia Tech's School of Electrical and computer Engineering (ECE) have worked jointly with engineers from National Instruments (NI) to develop a new freshman engineering course. This course i...
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Infinite games with incomplete information are common in practice. First-price, sealed-bid auctions are a prototypical example. To solve this kind of infinite game, a heuristic approach is to discretise the strategy s...
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In order to assist driver's vision, a real-time recognition system for traffic signs is proposed. After detecting sign candidates, biologically inspired opponent-color filters are used to extract symbol parts of s...
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ISBN:
(纸本)9781617387777
In order to assist driver's vision, a real-time recognition system for traffic signs is proposed. After detecting sign candidates, biologically inspired opponent-color filters are used to extract symbol parts of signs. After normalizing the size of symbol, structural features are calculated to identify the sign. 5572 segmented images are used to design the algorithm. In a real-time system, the same sign in a sequence of frames is tracked, and a majority vote is used to integrate the recognition results. For test data, 93.8% recall rate and 99.3% precision rate could be attained. In-vehicle experiment also showed high recall and precision rates.
With support from HBCU-UP (Historically Black College and University Undergraduateprogram) at National Science Foundation (NSF), the ACTION (Advanced Curriculum and Technology-Based Instructional Opportunities Networ...
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The urgent need in the field of nanotechnology is functional, reliable, and scalable techniques for more complicated and controlled nanostructures in order to realize nanoscale materials and devices that have practica...
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The urgent need in the field of nanotechnology is functional, reliable, and scalable techniques for more complicated and controlled nanostructures in order to realize nanoscale materials and devices that have practical use and more capability than existing technologies. This paper addresses this need by presenting an in vitro protocol to select large non-crosshybridizing (NCH) libraries of oligonucleotides that provide a large address space of DNA sequences with which to increase both complexity and control in DNA-directed self-assembly processes. The selection protocol was experimentally verified and confirmed. The resultant large NCH libraries would allow self-assembling complex nanostructures with more precise control, leading to reliable, scaled-up, cost-effective manufacturing of nanoscale devices and systems.
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