7,076 research outputs found
Quantum-implemented selective reconstruction of high-resolution images
This paper proposes quantum image reconstruction. Input-triggered selection
of an image among many stored ones, and its reconstruction if the input is
occluded or noisy, has been simulated by a computer program implementable in a
real quantum-physical system. It is based on the Hopfield associative net; the
quantum-wave implementation bases on holography. The main limitations of the
classical Hopfield net are much reduced with the new, original --
quantum-optical -- implementation. Image resolution can be almost arbitrarily
increased.Comment: 4 pages, 15 figures, essential
Adaptive link-weight routing protocol using cross-layer communication for MANET
Routing efficiency is one of the challenges offered by Mobile Ad-hoc Networks (MANETs). This
paper proposes a novel routing technique called Adaptive Link-Weight (ALW) routing protocol. ALW
adaptively selects an optimum route on the basis of available bandwidth, low delay and long route lifetime. The technique adapts a cross-layer framework where the ALW is integrated with application and physical layer. The proposed design allows applications to convey preferences to the ALW protocol to override the default path
selection mechanism. The results confirm improvement over AODV in terms of network load, route discovery time and link reliability
Numerical Estimate of Tangshan Earthquake Damage
The initial stress is first calculated quasi-statically under various loading conditions by using 3-dimenaional finite element model with double nodes to simulate the locked Tangsban fault. Once the shear stress at the front of fault tip reaches rupture criterion, the accumulated stress is suddenly released accompanying with frictional slip along the fault plane, the new state of stress imposed during faulting is re-calculated by reducing the shearing resistance of the hypocenter with the same boundary condition. Then the stress difference before and during shock is regarded as the driving force to generate ground motion. Numerical results show that both the fault mode and the loading system play an important role on the behavior of ground motion. To cause a greater damage and a tremendous depression on the seaward side of the fault, there must be a pre-existing oblique fault and the body force should be considered in addition to the horizontal stressing
Surface coatings and catalyst production by electrodeposition
Electrodeposition and electrocodeposition in low gravity are discussed. The goal is to provide a better understanding of the role of convection and buoyancy in the mechanisms of formation of some electrodeposited surfaces, fluid flow in the vicinity of electrodepositing surfaces, the influence of a moving medium upon codeposition, the effect of gravity upon the dispersion (coagulation) of neutral particles that are desired for codeposition and preparation of improved surface coatings and metal catalysts
Field trials and test results of portable DVB-T systems with transmit delay diversity
This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial was performed during the winter of 2007/2008 in Uxbridge (UK) to validate predictions from theoretical modeling and laboratory simulations. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive and indoor- non line of sight situations
Adaptive Transmission Techniques for Mobile Satellite Links
Adapting the transmission rate in an LMS channel is a challenging task
because of the relatively fast time variations, of the long delays involved,
and of the difficulty in mapping the parameters of a time-varying channel into
communication performance. In this paper, we propose two strategies for dealing
with these impairments, namely, multi-layer coding (MLC) in the forward link,
and open-loop adaptation in the return link. Both strategies rely on
physical-layer abstraction tools for predicting the link performance. We will
show that, in both cases, it is possible to increase the average spectral
efficiency while at the same time keeping the outage probability under a given
threshold. To do so, the forward link strategy will rely on introducing some
latency in the data stream by using retransmissions. The return link, on the
other hand, will rely on a statistical characterization of a physical-layer
abstraction measure.Comment: Presented at the 30th AIAA International Communications Satellite
Systems Conference (ICSSC), Ottawa, Canada, 2012. Best Professional Paper
Awar
An evolutionary strategy based motion estimation algorithm for H.264 video codecs
In this paper, we propose a new motion estimation algorithm based on evolutionary strategy (ES) for the H.264 video codec applied to monoscopic video. The proposed technique applies in macroblock basis and performs a parallel local search for the motion vector associated with the minimum motion compensated residue. For this purpose (/spl mu/+/spl lambda/)-ES is used with heuristically and randomly generated population of initial motion vectors. Experimental results show that the proposed scheme can reduce the computational complexity up to 50% of the motion estimation algorithm used in the H.264 reference codec at the same picture quality. Therefore, the proposed algorithm provides a significant improvement in motion estimation in the H.264 video codec
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