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排序方式: 共有374条查询结果,搜索用时 15 毫秒
61.
Mohamed Jleli Mokhtar Kirane Bessem Samet 《Computers & Mathematics with Applications》2018,75(8):2698-2709
In this paper, we study the nonlocal nonlinear evolution equation where , , , , is the convolution product in , and , , is the Caputo left-sided fractional derivative of order with respect to the time . We prove that the problem admits no global weak solution other than the trivial one with suitable initial data when . Next, we deal with the system where , , , and . We prove that the system admitsnon global weak solution other than the trivial one with suitable initial data when . Our approach is based on the test function method. 相似文献
62.
Mahmoodzadeh Arsalan Mohammadi Mokhtar Daraei Ako Farid Hama Ali Hunar Ismail Abdullah Abdulqadir Kameran Al-Salihi Nawzad 《Neural computing & applications》2021,33(1):321-348
Neural Computing and Applications - This research intends to use machine learning approaches to predict tunnel geology and its construction time and costs. For this purpose, the Gaussian Process... 相似文献
63.
Elyes Zarrouk Yassine Ben Ayed Faiez Gargouri 《International Journal of Speech Technology》2014,17(3):223-233
This paper presents a new hybrid method for continuous Arabic speech recognition based on triphones modelling. To do this, we apply Support Vectors Machine (SVM) as an estimator of posterior probabilities within the Hidden Markov Models (HMM) standards. In this work, we describe a new approach of categorising Arabic vowels to long and short vowels to be applied on the labeling phase of speech signals. Using this new labeling method, we deduce that SVM/HMM hybrid model is more efficient then HMMs standards and the hybrid system Multi-Layer Perceptron (MLP) with HMM. The obtained results for the Arabic speech recognition system based on triphones are 64.68 % with HMMs, 72.39 % with MLP/HMM and 74.01 % for SVM/HMM hybrid model. The WER obtained for the recognition of continuous speech by the three systems proves the performance of SVM/HMM by obtaining the lowest average for 4 tested speakers 11.42 %. 相似文献
64.
In process planning, determining feature’s machining precedence is an essential step. The task becomes more difficult if features
interact with each other, in which case the feature precedence information may suggest multiple machining sequences of the
features. This paper considers interacting features in a feature-based model for process planning tasks. For each feature,
precedence information is generated considering both roughing and finishing operations. A rule-based system is developed and
implemented based on the information about machining precedence of the interacting features. The STEP-NC data model is used
as the underlying data model. This model is object-oriented and compliant with the existing STEP standards. The output of
the system is also in the STEP format through an information model developed using the EXPRESS language. 相似文献
65.
This work presents an experimental study to assess the performance characteristics of hydrostatic thrust bearings. A test rig is designed for testing two configurations of hydrostatic bearings compensated by a capillary tube, one with a mid-circular recess and the other with multi-sectors (four recesses of different recess radii ratios). The performance characteristics have been measured, namely, oil film thickness, recess pressure, pressure distribution and oil flow rate. A specially devised computer program using an iterative technique has been adopted to compute numerically the pressure distribution and predict other performance characteristics. Good agreement has been obtained between predicted theoretical performance and that experimentally measured. The results demonstrate that the bearing recess size and location have a great influence on the performance of the hydrostatic thrust bearing. 相似文献
66.
Elena Cris Paola Boggione Maura Nicolosi Abdurraouf Mokhtar Mahmoud Wael Al Essa Bassel Awikeh Anna Aspesi Annalisa Andorno Renzo Boldorini Irma Dianzani Gianluca Gaidano Andrea Patriarca 《International journal of molecular sciences》2021,22(5)
Myelodysplastic syndromes (MDS) arising in the context of inherited bone marrow failure syndromes (IBMFS) differ in terms of prognosis and treatment strategy compared to MDS occurring in the adult population without an inherited genetic predisposition. The main molecular pathways affected in IBMFS involve telomere maintenance, DNA repair, biogenesis of ribosomes, control of proliferation and others. The increased knowledge on the genes involved in MDS pathogenesis and the wider availability of molecular diagnostic assessment have led to an improvement in the detection of IBMFS genetic predisposition in MDS patients. A punctual recognition of these disorders implies a strict surveillance of the patient in order to detect early signs of progression and promptly offer allogeneic hematopoietic stem cell transplantation, which is the only curative treatment. Moreover, identifying an inherited mutation allows the screening and counseling of family members and directs the choice of donors in case of need for transplantation. Here we provide an overview of the most recent data on MDS with genetic predisposition highlighting the main steps of the diagnostic and therapeutic management. In order to highlight the pitfalls of detecting IBMFS in adults, we report the case of a 27-year-old man affected by MDS with an underlying telomeropathy. 相似文献
67.
Shooka Khorramfar Niyaz Mohammad Mahmoodi Mokhtar Arami Kamaladin Gharanjig 《Coloration Technology》2010,126(5):261-268
In this paper, the use of tamarind hull biosorbent (Tamarindus indica) has been investigated to remove cationic dyes from textile eflluent. Basic Violet 6 and Basic Red 18 were used as cationic dye models. The surface characteristics of tamarind hull were investigated using Fourier Transform–infrared and scanning electron microscopy. The influence of process variables such as adsorbent dosage, initial dye concentration and pH were studied. The presence of fuctional groups such as hydroxy and amine groups onto the tamarind hull surface were proved by Fourier Transform–infrared analysis. Data were evaluated for compliance with the Langmuir and Freundlich isotherm models. The results indicated that the data for adsorption of Basic Violet 6 and Basic Red 18 onto tamarind hull fitted well with the Freundlich isotherm model. Also, the adsorption kinetics of Basic Violet 6 and Basic Red 18 on biosorbent was studied. The rates of sorption were found to conform to pseudo‐second‐order kinetics with good correlation. Results indicated that tamarind hull could be used as a biosorbent to remove cationic organics from contaminated watercourses. 相似文献
68.
Dhouha Krichène Amira Allalout Maria D. Salvador Giuseppe Fregapane Mokhtar Zarrouk 《European Journal of Lipid Science and Technology》2010,112(3):400-409
Fatty acids, volatiles, sterols, aliphatic and triterpenic alcohols of six monovarietal Tunisian virgin olive oils were analyzed. The results suggested that the compositional data concerning the above analytical fractions were effective in discriminating between varieties. The oils were found to contain high levels of oleic acid (up to 71.70% in the Oueslati variety). β‐Sitosterol (up to 85.46% in the Jdallou variety) and Δ5‐avenasterol (up to 30.97% in the El Hor variety) were the principal sterols in all samples; campesterol and stigmasterol were found at low levels. (E)‐2‐Hexenal was the main compound that characterizes the olive oil headspace of all samples. The other compounds identified were mainly C6 aliphatic components. 相似文献
69.
In this work, we studied the substitution effect of iron by gallium on the structural, magnetic and electrical properties of the ferrite system; Ni0.5Cu0.25Zn0.25Fe2−xGaxO4 (x = 0–1.0), synthesized by using the urea combustion method. XRD patterns of the samples calcined at 700 °C show only cubic spinel ferrite with an average crystallite sizes in the range of 40–54 nm. The lattice parameters were slightly changed with increasing Ga content which can be explained on the basis of the relative ionic radii of Ga3+ and Fe3+ ions. FT-IR measurements show two fundamental absorption bands, assigned to the vibration of tetrahedral and octahedral complexes, which were slightly changed with increasing Ga content. Mössbauer measurements enable us to predict the possible cation distribution of the system. It was found that Ga3+ ion prefer to substitute Fe3+ ions located in the octahedral site. Superparamagnetic state was observed in the Mössbauer spectra of the samples with Ga content >0.5. The decrease of the magnetic hyperfine field with gallium concentration was explained on the basis of supertransferred hyperfine interaction. A semiconducting behavior was inferred for all samples and the conductivity values were found to decrease with increasing the Ga content. The conduction mechanism in the spinel ferrite compounds was explained in terms of the hopping conduction process. The dielectric constant measured as a function of frequency and temperature was found to be dependent on the Ga concentration. The determined transition temperature was found to decrease with increasing Ga content. 相似文献
70.
Brahim Lakhrissi Loubna Lakhrissi Mohamed Massoui El Mokhtar Essassi Francesc Comelles Jordi Esquena Conxita Solans Carlos Rodríguez-Abreu 《Journal of surfactants and detergents》2010,13(3):329-338
The surface and self-aggregation properties in water of a new series of amphiphilic homologues, bis-benzimidazolone derivatives of d-glucose, were investigated. Parameters such as the maximal surface excess concentration, minimal area per molecule at the interface, and critical micelle concentration (CMC) were found to be significantly dependent on the hydrophobic alkyl chain length. The synthesized compounds form micelles at remarkably low concentrations, and CMCs derived from surface tension measurements show a minimum as a function of the alkyl chain length; this unusual trend can be attributed to the formation of submicellar aggregates in compounds with long alkyl chains, as evidenced from fluorescence probe spectroscopy data. At high surfactant concentrations, lyotropic liquid crystalline phases with hexagonal structure are formed. Small angle X-ray scattering measurements indicate that the characteristic nanoscopic lengths increase with water swelling and alkyl chain length. 相似文献