Many research studies have recently proposed the use of Impulse Radio based ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks because of it...
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Many research studies have recently proposed the use of Impulse Radio based ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks because of its numerous advantages. To harness these advantages at the physical-layer level of design, cross-layer architecture can be used to integrate different wireless short-range requirements into a smart wireless-tagged architecture. Adaptive transmission algorithm has been studied to show the trade-off flexibility between different specific quality of service requirements and transmission rate parameters at the physical-layer level in varied distance scenarios. This type of dynamic optimization and reconfiguration leads to the cross-layer design proposal introduced in this paper. The results of the theoretical and simulated analyses as well as the dedicated experimental design and implementations prove the validity of the proposed architecture. (C) 2012 Elsevier Ltd. All rights reserved.
This paper investigates the robust finite-time control problem for flexible spacecraft attitude tracking maneuver in the presence of model uncertainties and external disturbances. Two robust attitude tracking controll...
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This paper investigates the robust finite-time control problem for flexible spacecraft attitude tracking maneuver in the presence of model uncertainties and external disturbances. Two robust attitude tracking controllers based on finite-time second-order sliding mode control algorithms are presented to solve this problem. For the first controller, a novel second-order sliding mode control scheme is developed to achieve high-precision tracking performance. For the second control law, an adaptive-gain second-order sliding mode control algorithm combing an adaptive law with second-order sliding mode control strategy is designed to relax the requirement of prior knowledge of the bound of the system uncertainties. The rigorous proofs show that the proposed controllers provide finite-time convergence of the attitude and angular velocity tracking errors. Numerical simulations on attitude tracking control are presented to demonstrate the performance of the developed controllers.
Aimed at the multidimensional and complex characteristic of airport competitiveness, a new algorithm is proposed in which BP neural network is optimized by improved double chains quantum genetic algorithm (IDCQGA-BP)....
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Aimed at the multidimensional and complex characteristic of airport competitiveness, a new algorithm is proposed in which BP neural network is optimized by improved double chains quantum genetic algorithm (IDCQGA-BP). The new algorithm is better than existing algorithms in convergence and the diversity of quantumchromosomes. The empirical data of eight airports in Yangtze River Delta in 2011 and 2012 is applied to verify the feasibility of the new algorithm, and then the competitiveness of the eight airports from 2013 to 2015 is gotten through the algorithm. The results show the following. (1) The new algorithm is better than the existing optimization algorithms in the aspects of error accuracy and run time. (2) The gaps of the airports in Yangtze River Delta are narrowing;the competition and cooperation are getting stronger and stronger. (3) The main increase reason of airport competitiveness is the increase of own investment.
An ideal schedule minimizes both makespan and total flow time. It is known that the Coffman-Graham algorithm [Acta Informatica 1, 200-213, 1972] solves in polynomial time the problem of finding an ideal nonpreemptive ...
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An ideal schedule minimizes both makespan and total flow time. It is known that the Coffman-Graham algorithm [Acta Informatica 1, 200-213, 1972] solves in polynomial time the problem of finding an ideal nonpreemptive schedule of unit-execution-time jobs with equal release dates and arbitrary precedence constraints on two identical parallel processors. This paper presents an extension of the algorithm that solves in polynomial time the preemptive counterpart of this problem. The complexity status of the preemptive problem of minimizing just the total flow time has been open.
Clustering data has a wide range of applications and has attracted considerable attention in data mining and artificial intelligence. However it is difficult to find a set of clusters that best fits natural partitions...
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Clustering data has a wide range of applications and has attracted considerable attention in data mining and artificial intelligence. However it is difficult to find a set of clusters that best fits natural partitions without any class information. In this paper, a method for detecting the optimal cluster number is proposed. The optimal cluster number can be obtained by the proposal, while partitioning the data into clusters by FCM (Fuzzy c-means) algorithm. It overcomes the drawback of FCM algorithm which needs to define the cluster number.. in advance. The method works by converting the fuzzy cluster result into a weighted bipartite network and then the optimal cluster number can be detected by the improved bipartite modularity. The experimental results on artificial and real data sets show the validity of the proposed method.
Behavioural synthesis is the process whereby the description of a system behaviour is automatically translated into a physical implementation of that system. An essential prerequisite of this process is a language in ...
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Behavioural synthesis is the process whereby the description of a system behaviour is automatically translated into a physical implementation of that system. An essential prerequisite of this process is a language in which to express the design. Traditionally, hardware description languages (HDLs) are used for this, but there is currently much interest in the idea of coercing conventional software languages to do the same job (SystemC is the most prominent example of this). The goal of the research described is to increase the synthesisable description space to support the description of systems utilising dynamic allocation. VHDL supports the concepts of dynamic allocation, and is used as the entry language for the system, although without loss of validity SystemC could have been used. How the structures conventionally associated with dynamic description are implemented and supported is described together with a heap management subsystem that is both space and speed-efficient and which communicates with the user's design via an automatically generated interface.
In this work, we present suitable phase accuracy indicators, which are obtained from the first three obtained eigenvalues of the principal component analysis (PCA) demodulation algorithm. These indicators can be used ...
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In this work, we present suitable phase accuracy indicators, which are obtained from the first three obtained eigenvalues of the principal component analysis (PCA) demodulation algorithm. These indicators can be used in the measuring process to determine a blind phase goodness assessment, without the need of using any ground truth phase information. Therefore, it is possible to perform further actions if required, as obtaining more interferograms or repeat the measure. Additionally, we present simulated and experimental results that support our mathematical analysis and conclusions. A complete MATLAB software package reproducing any result and figure shown in this work is provided in (http://***/fy5EC).
One of the most important problems of reliable communications in shallow water channels is intersymbol interference (ISI) which is due to scattering from surface and reflecting from bottom. Using adaptive equalizers i...
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One of the most important problems of reliable communications in shallow water channels is intersymbol interference (ISI) which is due to scattering from surface and reflecting from bottom. Using adaptive equalizers in receiver is one of the best suggested ways for overcoming this problem. In this paper, we apply the family of selective regressor affine projection algorithms (SR-APA) and the family of selective partial update APA (SPU-APA) which have low computational complexity that is one of the important factors that influences adaptive equalizer performance. We apply experimental data from Strait of Hormuz for examining the efficiency of the proposed methods over shallow water channel. We observe that the values of the steady-state mean square error (MSE) of SR-APA and SPU-APA decrease by 5.8 (dB) and 5.5 (dB), respectively, in comparison with least mean square (LMS) algorithm. Also the families of SPU-APA and SR-APA have better convergence speed than LMS type algorithm.
Presents a computer algorithm which can be used to cluster order picking items in warehouses. Problems associated with picking items in a wide aisle; Objective of developing the algorithm; Comparison of picking time w...
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Presents a computer algorithm which can be used to cluster order picking items in warehouses. Problems associated with picking items in a wide aisle; Objective of developing the algorithm; Comparison of picking time with heuristic clustering methods.
The estimation accuracy of specular multipath components in radio channels that include dense multipath is investigated. Classical multipath estimation algorithms such as ESPRIT and SAGE do not include dense multipath...
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The estimation accuracy of specular multipath components in radio channels that include dense multipath is investigated. Classical multipath estimation algorithms such as ESPRIT and SAGE do not include dense multipath in their signal model whereas recent ones, such as RiMAX, do. These estimation algorithms are applied to a priori known synthetic channels which include both specular components (SCs) and dense multipath components (DMCs). The estimation errors of the SCs are computed as a function of the DMC power to evaluate the estimator's robustness. The results of this work clearly indicate large estimation errors for the SC parameters when the estimator does not include DMCs in its data model.
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