Analytic hierarchy process for multi-sensor data fusion based on belief function theory

Multi-sensor data fusion is an evolving technology whereby data from multiple sensor inputs are processed and combined. The data derived from multiple sensors can, however, be uncertain, imperfect, and conflicting. The present study is undertaken to help contribute to the continuous search for viable approaches to overcome the problems associated with data conflict and imperfection. Sensor readings, represented by belief functions, have to be fused according to their corresponding weights. Previous studies have often estimated the weights of sensor readings based on a single criterion. Mono-criteria approaches for the assessment of sensor reading weights are, however, often unreliable and inadequate for the reflection of reality. Accordingly, this work opts for the use of a multi-criteria decision aid. A modified Analytical Hierarchy Process (AHP) that incorporates several criteria is proposed to determine the weights of a sensor reading set. The approach relies on the automation of pairwise comparisons to eliminate subjectivity and reduce inconsistency. It assesses the weight of each sensor reading, and fuses the weighed readings obtained using a modified average combination rule. The efficiency of this approach is evaluated in a target recognition context. Several tests, sensitivity analysis, and comparisons with other approaches available in the literature are described.     

Stabilization of a standard gas mixture generator with diffusion tubes

Summary The generator contains diffusion tubes of known length and internal diameter. Once produced, the mixture of the carrier gas and acetone, the reference material, is sent through a chromatographic flame ionisation detector. Its signal reaches a constant level after a time corresponding to the stabilization time of the generator. The technique described is simple and gives repeatable results.     

Solvent free synthesis of 1,3-diaryl-2-propenones catalyzed by commercial acid-clays under ultrasound irradiation

This paper presents a novel solvent free method of synthesis of trans-chalcones. The method was based on ultrasound irradiation of the reagents (aryl methyl ketones and aryl aldehydes) in presence of commercial acid-montmorillonites as catalysts. The trans-chalcones were synthesized in high yields (85–95%) and excellent selectivity in a short reaction time.     

On the spectral analysis of many-body systems

We describe the essential spectrum and prove the Mourre estimate for quantum particle systems interacting through k-body forces and creation-annihilation processes which do not preserve the number of particles. For this we compute the “Hamiltonian algebra” of the system, i.e. the C^∗-algebra C generated by the Hamiltonians we want to study, and show that, as in the N-body case, it is graded by a semilattice. Hilbert C^∗-modules graded by semilattices are involved in the construction of C. For example, if we start with an N-body system whose Hamiltonian algebra is CN and then we add field type couplings between subsystems, then the many-body Hamiltonian algebra C is the imprimitivity algebra of a graded Hilbert CN-module.     

Inhibitory Effects of Tunisian Marine Algal Extracts on Digestive Lipases

The lipase inhibitory activity of ethanol extracts obtained from some marine algae collected on the Tunisian coast was evaluated. Caulerpa prolifera extract markedly reduced both dog gastric (DGL) and human pancreatic lipase (HPL) activities. Generally, the inhibition reached 100% after 40 to 60 min of incubation depending on lipase types and on substrates used. Moreover, the inhibitory effect of C. prolifera extract on lipases appeared to be accelerated by adding bile salts, which likely modified the interface and allowed the inhibitory compound to inactivate the lipase. The separation of C. prolifera extract by thin-layer chromatography (TLC) resulted in eight fractions showing efficient inhibition rate against DGL, compared to the crude extract. In the case of HPL, TLC fractionation reduced the inhibitory rates, suggesting that the effect of algal extract on lipases may be caused by a synergetic action of several compounds within the extract. High-performance liquid chromatograph separation resulted in isolation of a major compound displaying high inhibition capacity of HPL activity. Caulerpa prolifera extract may therefore be useful in developing antiobesity drugs.     

Structure of Hydrogen and Hydrophobically Bonded Amphiphilic Copolymer with Poly(methacrylic acid) Complexes as Revealed by Small Angle Neutron Scattering

We study by SANS the structure of intermolecular complexes formed through hydrogen bonding and hydrophobic interactions between poly(methacrylic acid) (PMA) and a neutral copolymer surfactant (PEO-PPO-PEO). The contrast variation method enables us to probe the structure factor of each polymer in the complex and their cross structure factor. The number of copolymer chains, which results from the cooperative action of hydrogen bonding and hydrophobic interactions increases as the charge of the polyacid decreases. The aggregation preserves the micellar core-corona organization of the copolymer and shrinks the polyacid chains which adopt a similar compact structure. Finally, the structure of the aggregates is compared to that of PEO-PMA homopolymer complex observed by SANS.     

Dual-channel spectral subtraction algorithms based speech enhancement dedicated to a bilateral cochlear implant

In this paper, two speech enhancement algorithms (SEAs) based on spectral subtraction (SS) principle have been evaluated for bilateral cochlear implant (BCI) users. Specifically, dual-channel noise power spectral estimation algorithm using power spectral densities (PSD) and cross power spectral density (CPSD) of the observed signals was studied. The enhanced speech signals were obtained using either Dual Channel Non Linear Spectral Subtraction ‘DC-NLSS’ or Dual-Channel Multi-Band Spectral Subtraction ‘DC-MBSS’ algorithms. For performance evaluation, some objective speech assessment tests relying on Perceptual Evaluation of Speech Quality (PESQ) score and speech Itakura-Saito (IS) distortion measurement were performed to fix the optimal number of frequency band needed in DC-MBSS algorithm. In order to evaluate the speech intelligibility, subjective listening tests were assessed with 50 normal hearing listeners using a specific BCI simulator and with three deafened BCI patients. Experimental results, obtained using French Lafon database corrupted by an additive babble noise at different Signal-to-Noise Ratios (SNR), showed that DC-MBSS algorithm improves speech understanding better than DC-NLSS algorithm for single and multiple interfering noise sources.     

Essential spectra of some matrix operators and application to two-group transport operators with general boundary conditions

In this article we investigate the essential spectra of a 2×2 block operator matrix on a Banach space. Furthermore, we apply the obtained results to determine the essential spectra of two-group transport operators with general boundary conditions in the Banach space Lp([−a,a]×[−1,1])×Lp([−a,a]×[−1,1]), a>0.     

On the Stationary Navier–Stokes Problem in $$\mathbb {R}^3$$: An Approach in Weighted Sobolev Spaces

In this paper, we study the steady-state Navier–Stokes equations in \(\mathbb {R}^3\). First, we establish the existence of very weak solution in \(\varvec{L}^p(\mathbb {R}^3)\) with \(3/2< p < +\infty \) under smallness conditions on the data. A uniqueness result is also given in case the data belong to \(\mathbb {L}^r(\mathbb {R}^3)\cap \mathbb {L}^{3/2}(\mathbb {R}^3)\) with \(3/2<r<3\). We also discuss the case where the data are not necessarily small. In particular, these results enhance those obtained by Bjorland et al. (Commun Partial Differ Equ 26:216–246, 2011), and are in agreement with those obtained by Kim and Kozono (J Math Anal Appl 395(2):486–495, 2012). Second, we prove a result of existence and uniqueness of weak solution in the weighted Sobolev space \(\varvec{W}_0^{1,p}(\mathbb {R}^3)\cap \varvec{W}_0^{1,\,3/2}(\mathbb {R}^3)\) in case of small external forces given by \(\mathrm{div}\mathbb {F}\) with \(\mathbb {F} \in \mathbb {L}^p(\mathbb {R}^3)\cap \mathbb {L}^{3/2}(\mathbb {R}^3)\) and \(1<p<3\).     

A ranking model in uncertain, imprecise and multi-experts contexts: The application of evidence theory

We consider ranking problems where the actions are evaluated on a set of ordinal criteria. The evaluation of each alternative with respect to each criterion may be imperfect and is provided by one or several experts. We model each imperfect evaluation as a basic belief assignment (BBA). In order to rank the BBAs characterizing the performances of the actions according to each criterion, a new concept called RBBD and based on the comparison of these BBAs to ideal or nadir BBAs is proposed. This is performed using belief distances that measure the dissimilarity of each BBA to the ideal or nadir BBAs. A model inspired by Xu et al.’s method is also proposed and illustrated by a pedagogical example.