When focusing on the general area of data mining, high-utility itemset mining (HUIM) can be defined as an offset of frequent itemset mining (FIM). It is known to emphasize more factors critically, which gives HUIM its intrinsic edge. Due to the flourishing development of the IoT technique, the uncertainty patterns mining is also attractive. Potential high-utility itemset mining (PHUIM) is introduced to reveal valuable patterns in an uncertainty database. Unfortunately, even though the previous methods are all very effective and powerful to mine, the potential high-utility itemsets quickly. These algorithms are not specifically designed for a database with an enormous number of records. In the previous methods, uncertainty transaction datasets would be load in the memory ultimately. Usually, several pre-defined operators would be applied to modify the original dataset to reduce the seeking time for scanning the data. However, it is impracticable to apply the same way in a big-data dataset. In this work, a dataset is assumed to be too big to be loaded directly into memory and be duplicated or modified; then, a MapReduce framework is proposed that can be used to handle these types of situations. One of our main objectives is to attempt to reduce the frequency of dataset scans while still maximizing the parallelization of all processes. Through in-depth experimental results, the proposed Hadoop algorithm is shown to perform strongly to mine all of the potential high-utility itemsets in a big-data dataset and shows excellent performance in a Hadoop computing cluster.
Photovoltaic power generation system becomes increasingly important, highly attractive as a clean and renewable energy sources, widely used today in many applications. Recently, researchers have strongly promoted the use of solar energy as a viable source of energy due to its advantages and which it can be integrated into local and regional power supplies. The P–V curve of photovoltaic system exhibits multiple peaks under various conditions of functioning and changes in meteorological conditions which reduces the effectiveness of conventional maximum power point tracking (MPPT) methods and the Particle swarm optimization (PSO) algorithm is considered to be highly efficient for the solution of complicated problems.In this paper, the application of this approach based MPPT algorithm for Photovoltaic power generation system operating under variable conditions is proposed to optimize and to design an intelligent controller comparing to conventional one. PSO Approaches is considered to select and generate an optimal duty cycle which varies with photovoltaic parameters in order to extract the maximum Power. Simulation results show that the proposed approach can track the maximum power point faster and can improve the performance of the system compared to the conventional method. 相似文献
This paper deals with robust bond graph model-based fault detection and isolation to improve the robustness of the diagnosis system in presence of measurements and parameters uncertainties. We develop a procedure of measurement uncertainties modeling directly on the graph. By using the structural and causal properties of the bond graph, the robust diagnosis is performed. The interest of the developed methodology consists in using the graphical tool not only for measurement uncertainties modeling, but also for designing robust fault detection and isolation algorithms. Moreover, this method can be easily automated. The developed approach is validated by an application to an electromechanical traction system of intelligent autonomous vehicle. 相似文献
The wavelet decomposition has become an attractive tool for fusing multisensor images. Usually, the input images are decomposed with an orthogonal wavelet in order to extract features, which are combined through an appropriate fusion rule. The fused image is then reconstructed by applying the inverse wavelet transform. In this paper, we investigate the use of the nonorthogonal (or redundant) wavelet decomposition as an alternative approach for feature extraction. By using test and remote sensing images, various fusion rules are considered and the detailed comparison indicates the superiority of this approach compared to the standard orthogonal wavelet decomposition for image fusion. 相似文献
The distribution of the solvent-extractable organic components in the fine (PM1) and coarse (PM1-10) fractions of airborne particulate was studied for the first time in Algeria. That was done during October 2006 concurrently in a big industrial district, a busy urban area, and a forest national park located in Algiers, Boumerdes, Blida, respectively, which are the three biggest provinces of Northern Algeria. Most of the organic matter identified in both particle size ranges consisted of n-alkanes and n-alkanoic acids, with minor contributions coming from polycyclic aromatic hydrocarbons (PAHs), nitrated polycyclic aromatic hydrocarbons (NPAHs), oxygenated PAHs, and other polar compounds (e.g., caffeine and nicotine). The potential emission sources of airborne contaminants were reconciled by combining the values of n-alkane carbon preference index (CPI) and selected diagnostic ratios of PAHs, calculated in both size ranges. The mean cumulative concentrations of PAHs reached 3.032 ng m− 3 at the Boumerdes site, urban, 80% of which (i.e. 2.246 ng m− 3) in the PM1 fraction, 6.462 ng m− 3 at Rouiba-Réghaia, industrial district, (5.135 ng m− 3 or 80% in PM1), and 0.512 ng m− 3 at Chréa, forested mountains (0.370 ng m− 3 or 72% in PM1). Similar patterns were shown by all organic groups, which resulted overall enriched in the fine particles at the three sites. Carcinogenic and mutagenic potencies associated to PAHs were evaluated by multiplying the concentrations of “toxic” compounds times the corresponding potency factors normalized vs. benzo(a)pyrene (BaP), and were found to be both acceptable. 相似文献
Various chelating ligands have been investigated for the cloud point extraction of several metal ions. However, limited studies on the use of the Schiff base ligands have been reported. In this work, cloud point extraction behavior of copper(II) with N,N′‐bis(salicylaldehyde)Ethylenediimine Schiff base chelating ligand, (H2SALEN), was investigated in aqueous concentrated sulphate medium. The extraction process used is based on the formation of hydrophobic H2SALEN–copper(II) complexes that are solubilized in the micellar phase of a non‐ionic surfactant, i.e. ethoxylated (9.5EO) tert‐butylphenol. The copper(II) complexes are then extracted into the surfactant‐rich phase above cloud point temperature. Different parameters affecting the extraction process of Cu(II), such as equilibrium pH, extractant concentration, and non‐ionic surfactant concentration were explored. The extraction of Cu(II) was studied in the pH range of 2–11. The results obtained showed that it was profoundly influenced by the pH of the aqueous medium. The concentration factor, Cf, of about 17 with extraction efficiency of E % ≈100 was achieved. The stoichiometry of the extracted complex of copper(II) was ascertained by the Yoe–Jones method to give a composition of 1:1 (Cu:H2L). The optimum conditions of the extraction‐removal have been established as the following: (1) 1.86 × 10?3 mol/L ligand; (2) 3 wt% surfactant; (3) pH of 8 (4) 0.5 mol/L Na2SO4 and (5) temperature of 60 °C. 相似文献
This paper deals with the diagnostic yttria-stabilized zirconia (YSZ) in-flight particles in Vacuum Plasma Spray (VPS) process using an optical measurement device. Particle velocity, temperature and diameter were correlated to spray distance under a fixed chamber pressure of about 14 kPa. Experiments were carried out with a two-color pyrometer. Results show that correlations can be satisfactory described with linear relationships. Particle velocity and temperature decrease when increasing spray distance whereas particle diameter exhibits a linear increase with the spray distance. 相似文献