2,693 research outputs found
Optimal pilot placement for frequency offset estimation and data detection in burst transmission systems
In this letter, we address the problem of pilot design
for Carrier Frequency Offset (CFO) and data detection in digital burst transmission systems. We consider a quasi-static flat-fading channel. We find that placing half of the pilot symbols at the beginning of the burst and the other half at the end of the burst is optimal for both CFO estimation and data detection. Our findings are based on the CramĀ“er-Rao bound and on empirical evaluations of the bit error rate for different pilot designs. The
equal-preamble-postamble pilot design is shown to provide a
significant gain in performance over the conventional preambleonly pilot design
Exploiting Group Symmetry in Truss Topology Optimization
AMS classification: 90C22, 20Cxx, 70-08truss topology optimization;semidefinite programming;group symmetry
Automatic summarization of rushes video using bipartite graphs
In this paper we present a new approach for automatic summarization of rushes video. Our approach is composed of three main steps. First, based on a temporal segmentation, we filter sub-shots with low information content not likely to be useful in a summary. Second, a method using maximal matching in a bipartite graph is adapted to measure similarity between the remaining shots and to minimize inter-shot redundancy by removing repetitive retake shots common in rushes content. Finally, the presence of faces and the motion intensity are characterised in each sub-shot. A measure of how representative the sub-shot is in the context of the overall video is then proposed. Video summaries composed of keyframe slideshows are then generated. In order to evaluate the effectiveness of this approach we re-run the evaluation carried out by the TREC, using the same dataset and evaluation metrics used in the TRECVID video summarization task in 2007 but with our own assessors. Results show that our approach leads to a significant improvement in terms of the fraction of the TRECVID summary ground truth included and is competitive with other approaches in TRECVID 2007
A new primal-dual path-following interior-point algorithm for semidefinite optimization
AbstractIn this paper we present a new primal-dual path-following interior-point algorithm for semidefinite optimization. The algorithm is based on a new technique for finding the search direction and the strategy of the central path. At each iteration, we use only full NesterovāTodd step. Moreover, we obtain the currently best known iteration bound for the algorithm with small-update method, namely, O(nlognĻµ), which is as good as the linear analogue
A Magnetorheological Damper with Embedded Piezoelectric Force Sensor: Experiment and Modeling
This chapter describes configuration, fabrication, calibration and performance tests of the devised self-sensing MR damper firstly. Then, a black-box identification approach for modeling the forward and inverse dynamics of the self-sensing MR damper is presented, which is developed with the synthesis of NARX model and neural network within a Bayesian inference framework to have the ability of enhancing generalization.Department of Civil and Environmental Engineerin
A case study in model-driven synthetic biology
We report on a case study in synthetic biology, demonstrating the modeldriven
design of a self-powering electrochemical biosensor. An essential result of
the design process is a general template of a biosensor, which can be instantiated
to be adapted to specific pollutants. This template represents a gene expression network
extended by metabolic activity. We illustrate the model-based analysis of this
template using qualitative, stochastic and continuous Petri nets and related analysis
techniques, contributing to a reliable and robust design
Parity and Time Reversal in the Spin-Rotation Interaction
A recently reported discrepancy between experimental and theoretical values
of the muon's g-2 factor is interpreted as due to small violations of the
conservation of P and T in the spin-rotation coupling. The experiments place an
upper limit on these violations and on the weight change of spinning
gyroscopes.Comment: 3 page
Effect of copper, cadmium and Cu.Cd mixture on amino acid content in the poslarvae of penaeid shrimp, Penaeus monodon and P. penicillatus
This study document effects of short-term (96h) sublethal levels of copper,
cadmium and their mixture on the amino acid composition of postlarvae of the penaeid shrimp, P.monodon and P.penicillatus . All experimental conditions were kept constant, temperature between 25-27ā¢C and salinity 21-22 ppt. The estimated LD50 for Cu was 200 ug/L, for Cd 177.5
ug/L and for Cu.Cd mixture 250ug/L. In P. penicillatus at the same concentration of each metal, there was significant reduction in amino acid content, which was 8.01% higher than the control. Almost similar reduction in some amino acids was observed in P.monodon. At the maximum
concentration of 400 ug/L, cadmium caused higher reduction in amino acid composition than did copper. Thus, amino acid composition may be regarded as a sensitive biochemical indicator of Cu and Cd toxicity because of the effect of these metals on protein synthesis, a signal of physiological stress in marine organisms subjected to heavy metal pollution
Constraints and Soliton Solutions for the KdV Hierarchy and AKNS Hierarchy
It is well-known that the finite-gap solutions of the KdV equation can be
generated by its recursion operator.We generalize the result to a special form
of Lax pair, from which a method to constrain the integrable system to a
lower-dimensional or fewer variable integrable system is proposed. A direct
result is that the -soliton solutions of the KdV hierarchy can be completely
depicted by a series of ordinary differential equations (ODEs), which may be
gotten by a simple but unfamiliar Lax pair. Furthermore the AKNS hierarchy is
constrained to a series of univariate integrable hierarchies. The key is a
special form of Lax pair for the AKNS hierarchy. It is proved that under the
constraints all equations of the AKNS hierarchy are linearizable.Comment: 12 pages, 0 figur
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