Boolean factors as a means of clustering of interestingness measures of association rules

Measures of interestingness play a crucial role in association rule mining. An important methodological problem, on which several papers appeared in the literature, is to provide a reasonable classification of the measures. In this paper, we explore Boolean factor analysis, which uses formal concepts corresponding to classes of measures as factors, for the purpose of clustering of the measures. Unlike the existing studies, our method reveals overlapping clusters of interestingness measures. We argue that the overlap between clusters is a desired feature of natural groupings of measures and that because formal concepts are used as factors in Boolean factor analysis, the resulting clusters have a clear meaning and are easy to interpret. We conduct three case studies on clustering of measures, provide interpretations of the resulting clusters and compare the results to those of the previous approaches reported in the literature.     

Analytical evaluation of six monovarietal virgin olive oils from Northern Tunisia

The characterization of virgin olive oils from six Tunisian cultivars, namely Chétoui, Ain Jarboua, Jarboui, Regregui, Rekhami and Neb Jmel, grown in Nebeur (a region of the Kef) was carried out. These cultivars dominate their natural habitats, but with the exception of the Chétoui cultivar they are only scattered throughout the nation. Several analytical parameters were evaluated; these include quality index, fatty acid composition, chlorophylls, carotenoids, sterols, α‐tocopherol and phenolic compounds. Their relationship with oxidative stability was also tested. The main phenols found were tyrosol, hydroxytyrosol, the dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol, oleuropein aglycon and pinoresinol. These phenolic compounds, the colorimetric total phenol content and o‐diphenols showed significant correlations with oxidative stability. Furthermore, most of the analytical parameters of the oils that were determined in this study were greatly influenced by genetic factors (cultivar).     

Physiological and behavioral responses of Orchestia gammarellus (Amphipoda,Talitridae) towards trace elements contamination soil

Effects of trace elements on the hepatopancreas ultrastructure and on the locomotor activity rhythm were investigated in the amphipod talitrid Orchestia gammarellus collected from Bizerte lagoon banks situated in the north of Tunisia. Animals were exposed to a series of contaminated soil with different concentrations of cadmium and zinc. The locomotor activity rhythm was studied under constant darkness. Histopathological analysis showed that the trace elements, especially the Cd, induced significant changes in the morphology and in the ultrastructural organization of hepatopancreatic cells. The significant alterations obtained were dose dependent. Concerning the behavioral response, results revealed the presence of two components whatever the experimental conditions. In addition, a great inter-individual variability of the locomotor rhythm was observed. Patterns were in majority bimodal for the control individuals and became unimodal and multimodal when exposed under Cd and Zn, respectively. Furthermore, ultradian and circadian periods were determined. The circadian period lengthened after Zn exposure. In addition, the locomotor activity rhythm was more stable for control individuals. However, those exposed to Cd were less active.     

Robust Integral Sliding Mode Control of Uncertain Networked Control Systems with Multiple Data Packet Losses

In this paper, a robust integral sliding mode control problem for networked control systems with multiple data packet losses is investigated. The data packet losses occur in both sensor-to-controller and controller-to-actuator channels in a random way and they are modelled by independent Bernoulli binary distributed white sequences. The considered class of system is also subject to matched uncertainties and external disturbances presence. A specific sliding mode surface which take into consideration the stochastic nature of the system is proposed to generate a stable sliding mode dynamics for closed loop system. An integral sliding mode controller is designed to ensure the reachability of the specified sliding mode domain. Finally, simulation results, carried out on a linearized model of cart pendulum system, illustrate the effectiveness of the proposed approach.     

New alkaline trypsin from the intestine of Grey triggerfish (Balistes capriscus) with high activity at low temperature: Purification and characterisation

A highly alkaline trypsin from the intestine of Grey triggerfish (Balistes capriscus), with high activity at low temperature, was purified and characterised. The enzyme was purified to homogeneity using acetone precipitation, Sephadex G-100 gel filtration and Mono Q-Sepharose anion-exchange chromatography, with a 13.9-fold increase in specific activity and 41.3% recovery. The molecular weight of the purified alkaline trypsin was estimated to be 23.2 kDa by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and size exclusion chromatography. Purified trypsin appeared as a single band on native–PAGE. Interestingly, the enzyme was highly active over a wide range of pH, from 9.0 to 11.5, with an optimum at pH 10.5, using Nα-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as a substrate. The relative activities at pH 9.0, 11.5 and 12.0 were 86.5%, 92.6% and 52.4%, respectively. The enzyme was extremely stable in the pH range 7.0–12.0. In addition, the enzyme had high activity at low and moderate temperatures with an optimum at around 40 °C and had more than 80% of its maximum activity at 20 °C. The purified enzyme was strongly inhibited by soybean trypsin inhibitor (SBTI) and phenylmethylsulphonyl fluoride (PMSF), a serine protease inhibitor. The enzyme showed extreme stability towards oxidising agents, retaining about 87% and 80% of its initial activity after 1 h incubation at 40 °C in the presence of 1% sodium perborate and 1% H₂O₂, respectively. In addition, the enzyme showed excellent stability and compatibility with some commercial solid detergents.     

Glycolipid biosurfactants: main properties and potential applications in agriculture and food industry

Glycolipids, consisting of a carbohydrate moiety linked to fatty acids, are microbial surface active compounds produced by various microorganisms. They are characterized by high structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Rhamnolipids, trehalolipids, mannosylerythritol lipids and cellobiose lipids are among the most popular glycolipids. They have received much practical attention as biopesticides for controlling plant diseases and protecting stored products. As a result of their antifungal activity towards phytopathogenic fungi and larvicidal and mosquitocidal potencies, glycolipid biosurfactants permit the preservation of plants and plant crops from pest invasion. Also, as a result of their emulsifying and antibacterial activities, glycolipids have great potential as food additives and food preservatives. Furthermore, the valorization of food byproducts via the production of glycolipid biosurfactant has received much attention because it permits the bioconversion of byproducts on valuable compounds and decreases the cost of production. Generally, the use of glycolipids in many fields requires their retention from fermentation media. Accordingly, different strategies have been developed to extract and purify glycolipids. © 2016 Society of Chemical Industry     

Analysis of three-dimensional turbo codes

Our paper presents a detailed study of the three-dimensional turbo code (3D TC). This code which combines both parallel and serial concatenation is derived from the classical TC by concatenating a rate-1 post-encoder at its output. The 3D TC provides very low error rates for a wide range of block lengths and coding rates, at the expense of an increase in complexity and a loss in convergence. This paper deals with the performance improvement of the 3D TC. First, we optimize the distance spectrum of the 3D TC by means of the adoption of a non regular post-encoding pattern. This allows us to increase the minimum hamming distance (MHD) and thereby to improve the performance at very low error rates. Then, we propose a time varying construction of the post-encoded parity in order to reduce the observable loss of convergence at high error rates. Performance comparisons are made between the 3GPP2 standardized TC and the corresponding 3D code. The different improvement stages are illustrated with simulation results, asymptotical bounds, and EXIT charts.     

Thermal fatigue of cast irons for automotive application

The thermal fatigue damage constitutes the major problem of the parts subject to a variation in temperature during their operation. Several materials have been used for such structures in order to limit their damage. The facility of implementation and low cost of cast iron constitute an advantage for its use for the Diesel motors.