Static and incremental dynamic approaches for multi-objective bitmap join indexes selection in data warehouses

The Journal of Supercomputing - Data warehouses are very large databases and play key role in intelligent decision making in enterprises. The bitmap join indexes selection problem is crucial in the...     

Efficient visual tracking approach via whale optimizer and corrected background weighted histogram

Multimedia Tools and Applications - There are mainly two components in almost every visual object tracking algorithm, which are the object presentation and the searching mechanism. In the...     

Improvements of Adaptive Filtering by Optimal Projection to filter different artifact types on long duration EEG recordings

Adaptive Filtering by Optimal Projection (AFOP) is an automatic method for reducing ocular and muscular artifacts on electro-encephalographic (EEG) recordings. This paper presents two additions to this method: an improvement of the stability of ocular artifact filtering and an adaptation of the method for filtering electrode artifacts. With these improvements, it is possible to reduce almost all the current types of artifacts, while preserving brain signals, particularly those characterising epilepsy. This generalised method consists of dividing the signal into several time-frequency windows, and in applying different spatial filters to each. Two steps are required to define one of these spatial filters: the first step consists of defining artifact spatial projection using the Common Spatial Pattern (CSP) method and the second consists of defining EEG spatial projection via regression. For this second step, a progressive orthogonalisation process is proposed to improve stability. This method has been tested on long-duration EEG recordings of epileptic patients. A neurologist quantified the ratio of removed artifacts and the ratio of preserved EEG. Among the 330 artifacted pages used for evaluation, readability was judged better for 78% of pages, equal for 20% of pages, and worse for 2%. Artifact amplitudes were reduced by 80% on average. At the same time, brain sources were preserved in amplitude from 70% to 95% depending on the type of waves (alpha, theta, delta, spikes, etc.). A blind comparison with manual Independent Component Analysis (ICA) was also realised. The results show that this method is competitive and useful for routine clinical practice.     

Experimental and numerical investigation of the debonding interface between an old concrete and an overlay

The paper focuses on debonding propagation along an interface, notably on the major influence of the interlocking between the two faces of the debonding interface. The aim of the study is to obtain the data necessary for relevant and efficient debonding modelling. The work associates experiment and simulation with the purpose of quantifying the interlocking along the interface. The overlay material investigated was a fibre reinforced mortar (FRM). Direct tension tests of notched FRM specimens were firstly conducted to obtain the tensile strength and the residual normal stress—crack width relationship. Its Young's modulus was determined from compression tests. The substrate-overlay interface was investigated by direct tension tests and flexure tests performed on composite substrate-overlay specimens. The direct tension tests provided the interface tensile strength and the relationship between debonding-opening and residual normal tensile stress. Three point flexural static tests informed on the structural behaviour of the interface. The debonding interface propagation was monitored using a video-microscope with a maximum enlargement of ×175. Using the identified and quantified parameters, modelling of the above mentioned static tests was carried out by the finite elements method using CAST3M code developed in France by CEA (Centre for Atomic Energy). The comparison of modelling and experiment results shows a good coherence and proves the important role of interlocking on the debonding mechanism.     

Mechanical properties of steel fibre reinforced and rubberised cement-based mortars

Previous studies demonstrated that crack cutting bonded cement-based repairs is highly detrimental to the durability of such applications. Laboratory tests and field experience showed that fibre reinforcement allowing the control of the crack opening and assuring the structural continuity is a solution to enhance the durability of bonded cement-based repairs. In other respect, recent work pointed out that the use of rubber aggregates obtained from grinding end-of-life tyres is a suitable solution to improve the strain capacity of cement-based materials. The present contribution focuses on the synergetic effect of rubber aggregate incorporation and of fibre reinforcement from the point of view of the use of the composite in the repair work application.     

A novel 3D dual active contours approach

Pattern Analysis and Applications - This paper investigates a 3D novel dual active contours approach to segment multiple regions in medical images. The locally based segmentation approaches can...     

Improving the Throughput in Lightly Disturbed IEEE 802.11 DCF Saturated Network Using the Fragmentation Mechanism Under Basic Access Mode

Wireless Personal Communications - The IEEE 802.11 is the most dominating protocol in the wireless local area networks and in which, the fundamental mechanism to access the channel is called...     

The kinetics and mechanism of caffeine infusion from coffee: The hindrance factor in intra-bean diffusion

Green and medium-roast Kenyan arabica coffees were ground and sieved, and the 0·85–1·8 mm size fractions partially converted into two water-swollen forms by an appropriate series of treatments. The first form still contained a mix of coffee solubles, the second only caffeine. The rates of caffeine infusion into water at 80°C were then measured for the dry coffee and for the two water-swollen preparations. The caffeine was extracted two to three times faster from the solute-free water-swollen preparation than from the dry material Analysis of the results showed that counterflow of water the swelling of coffee particles, caffeine association with other solubes and physical restraints within the bean matrix all contribute to the low diffusion coefficient of caffeine inside the coffee particles. The behaviour of the green and the medium roast coffees was surprisingly similar.     

Incident angle effect of the primary beam upon the mean depth of electrons in a target

When a target is bombarded by a mono-energetic beam, it emits several signals (back-scattered and secondary electrons, electromagnetic rays: X-rays, ir, uv, ...). Qualitative electron-probe microanalysis is based on the measurement of some radiation X. The X radiation intensity depends on the initial energy of the incident beam, on the element concentration which corresponds to the radiation, and, on the direction of the incident beam with regard to the plane surface of the target. Few programs study the effect resulting from varying the beam incidence angle. It is important to know to what extent parameters of microanalysis are effected by changes in the beam incidence angle. In this paper, we attempt to study the mean depth reached by incident electrons in a semi-infinite target. In fact, the absorption factor increases when the incidence angle decreases: this is because characteristic X-rays are generated closer to the target surface.     

Adaptive fuzzy sliding mode controller for a class of SISO nonlinear time-delay systems

In this paper, we propose an adaptive fuzzy controller for a class of nonlinear SISO time-delay systems. The plant model structure is represented by a Takagi–Sugeno (T–S) type fuzzy system. The T–S fuzzy model parameters are adjusted online. The proposed algorithm utilizes the sliding surface to adjust online the parameters of T–S fuzzy model. The controller is based on adjustable T–S fuzzy parameters model and sliding mode theory. The stability analysis of the closed-loop system is based on the Lyapunov approach. The plant state follows asymptotically any bounded reference signal. Two examples have been used to check performances of the proposed fuzzy adaptive control scheme.