Correction to: 2D and 3D image localization,compression and reconstruction using new hybrid moments

Multidimensional Systems and Signal Processing -     

Back-to-Back Butterfly Network,an Adaptive Permutation Network for New Communication Standards

In this paper, we introduce a Back-to-Back Butterfly Network (B²BN) based on multiplexers (MUXs) in which any kind of permutation can be performed. However, for a given permutation, it is not an easy task to select the appropriate paths in B²BN without any conflict in terms of MUXs. In this paper, we propose a formal model to efficiently solve such conflicts. The proposed method relies on collecting the sets of potential paths that transfer an input to an output. Then, a path from each set is selected respecting a conflict free constraint. Once the appropriate paths are selected, the control signals of the MUXs are generated. This model has been experimented with 5G communication, showing how to process several frames in parallel with different permutation constraints.

     

On optimal relaying strategies for VANETs over double Nakagami-m fading channels

Wireless Networks - Vehicular ad hoc networks (VANETs) are able to facilitate data exchange among vehicles and provide diverse data services. The benefits of cooperative communications are such as...     

An Optimized IR-UWB Communication System with Interference Reduction on a Narrowband System Using Genetic Algorithm

This paper proposed a new impulse radio ultra wideband (IR-UWB) signal to reduce interference on narrowband systems at high usage 5.2 GHz frequency. The combination of 4th and 5th order derivatives of Gaussian pulses were employed to generate the signal so that satisfy the US Federal Communications Commission (FCC) mask. The genetic algorithm technique was used to find the pulse optimized parameters. In this paper, spectrum was optimized by changing the shape factor (sigma) and amplitude of Gaussian pulses so that the transmitted power spectrum density was minimized at a frequency of 5.2 GHz and maximized at the other frequencies from 3.1 to 10.6 GHz according to the FCC mask. The signal was applied in an IR-UWB transceiver system with binary-phase shift keying modulation. The IR-UWB waveform is generated by a programmable digital to analog based circuit. The proposed system was compared with conventional IR-UWB systems at the same condition. The simulation results in multipath channel showed that the proposed system not only reduced interference with the narrowband system, but also this was robust against narrowband interference at 5.2 GHz frequency.

     

Investigation of tensile and in-plane shear properties of carbon fiber reinforced composites with and without piezoelectric patches for micro-crack propagation using extended finite element method

Microsystem Technologies - The smart materials are capable to integrate the remarkabale active functions into a traditional structure of the composites. There is a wide research possibility towards...     

Piezoelectric thermo electromechanical energy harvester for reconnaissance satellite structure

Microsystem Technologies - Piezoelectric materials are widely used in aerospace industry as a source of alternate energy for micro or nanoscale electronics because of voltage dependent actuation...     

Revisiting the performance of automated approaches for the retrieval of duplicate reports in issue tracking systems that perform just-in-time duplicate retrieval

Issue tracking systems (ITSs) allow software end-users and developers to file issue reports and change requests. Reports are frequently duplicately filed for the same software issue. The retrieval of these duplicate issue reports is a tedious manual task. Prior research proposed several automated approaches for the retrieval of duplicate issue reports. Recent versions of ITSs added a feature that does basic retrieval of duplicate issue reports at the filing time of an issue report in an effort to avoid the filing of duplicates as early as possible. This paper investigates the impact of this just-in-time duplicate retrieval on the duplicate reports that end up in the ITS of an open source project. In particular, we study the differences between duplicate reports for open source projects before and after the activation of this new feature. We show how the experimental results of prior research would vary given the new data after the activation of the just-in-time duplicate retrieval feature. We study duplicate issue reports from the Mozilla-Firefox, Mozilla-Core and Eclipse-Platform projects. In addition, we compare the performance of the state of the art of the automated retrieval of duplicate reports using two popular approaches (i.e., BM25F and REP). We find that duplicate issue reports after the activation of the just-in-time duplicate retrieval feature are less textually similar, have a greater identification delay and require more discussion to be retrieved as duplicate reports than duplicates before the activation of the feature. Prior work showed that REP outperforms BM25F in terms of Recall rate and Mean average precision. We observe that the performance gap between BM25F and REP becomes even larger after the activation of the just-in-time duplicate retrieval feature. We recommend that future studies focus on duplicates that were reported after the activation of the just-in-time duplicate retrieval feature as these duplicates are more representative of future incoming issue reports and therefore, give a better representation of the future performance of proposed approaches.     

Control of Grid Connected Photovoltaic Systems with Microinverters: New Theoretical Design and Numerical Evaluation

This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single‐phase full‐bridge inverter, a filter inductor, and an isolation transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF) in the grid. To achieve these objectives, a new multiloop nonlinear controller is designed using the backstepping design technique. A key feature of the control design is that it relies on an averaged nonlinear system model accounting, on the one hand, for the nonlinear dynamics of the underlying boost converter and inverter and, on the other, for the nonlinear characteristic of the PV panel. To achieve the MPPT objective, a power optimizer is designed that computes online the optimal PV panel voltage used as a reference signal by the PV voltage regulator. It is formally shown that the proposed controller meets all the objectives. This theoretical result is confirmed by numerical simulation tests.     

3D radial invariant of dual Hahn moments

In this work, we propose new sets of 2D and 3D rotation invariants based on orthogonal radial dual Hahn moments, which are orthogonal on a non-uniform lattice. We also present theoretical mathematics to derive them. Thus, this paper presents in the first case new 2D radial dual Hahn moments based on polar representation of an image by one-dimensional orthogonal discrete dual Hahn polynomials and a circular function. The dual Hahn polynomials are general case of Tchebichef and Krawtchouk polynomials. In the second case, we introduce new 3D radial dual Hahn moments employing a spherical representation of volumetric image by one-dimensional orthogonal discrete dual Hahn polynomials and a spherical function, which are orthogonal on a non-uniform lattice. The 2D and 3D rotational invariants are extracts from the proposed 2D and 3D radial dual Hahn moments respectively. In order to test the proposed approach, three problems namely image reconstruction, rotational invariance and pattern recognition are attempted using the proposed moments. The result of experiments shows that the radial dual Hahn moments have performed better than the radial Tchebichef and Krawtchouk moments, with and without noise. Simultaneously, the mentioned reconstruction converges quickly to the original image using 2D and 3D radial dual Hahn moments, and the test images are clearly recognized from a set of images that are available in COIL-20 database for 2D image and PSB database for 3D image.

     

An entropy-based distance measure for analyzing and detecting metamorphic malware

Metamorphic malware is a kind of malware which evades signature-based anti-viruses by changing its internal structure in each infection. This paper, firstly, introduces a new measure of distance between two computer programs called program dissimilarity measure based on entropy (PDME). Then, it suggests a measure for the degree of metamorphism, based on the suggested distance measure. The distance measure is defined based on the Entropy of the two malware programs. Moreover, the paper shows that the distance measure can be used for classifying metamorphic malware via K-Nearest Neighbors (KNN) method. The method is evaluated by four metamorphic malware families. The results demonstrate that the measure can indicate the degree of metamorphism efficiently, and the KNN classification method using PDME can classify the metamorphic malware with a high precision.