integrally skinned asymmetric membranes based on nanocompositepolyethersulfone were prepared by the phase separation process using the supercritical co2 as a nonsolvent for the polymer solution. in present study, the effects of temperature and nanoparticle on selectivity performance and permeability of gases has beeninvestigated. it is shown that the presence of silica nanoparticles not only di...

reservoir permeability is a critical parameter for characterization of the hydrocarbon reservoirs. in fact, determination of permeability is a crucial task in reserve estimation, production and development. traditional methods for permeability prediction are well log and core data analysis which are very expensive and time-consuming. well log data is an alternative approach for prediction of pe...

introduction:  breast  cancer  is  a  leading  cause  of  death  among  females  throughout  the  world.  currently,  radiologists are able to detect only 75% of breast cancer cases. making use of computer-aided design (cad)  can play an important role in helping radiologists perform more accurate diagnoses.   material and methods: using our hybrid method, the background and the pectoral muscle...

bivariate features, obtained from multichannel electroencephalogram (eeg) recordings, quantify the relation between different brain regions. studies based on bivariate features have shown optimistic results for tackling epileptic seizure prediction problem in patients suffering from refractory epilepsy. a new bivariate approach using univariate features is proposed here. differences and ratios ...

in recent years, the needs of the internet are felt in lives of all people.  accordingly, many studies have been done on security in virtual environment. old technics such as firewalls, authentication and encryption could not provide internet security completely; so, intrusion detection system is created as a new solution and a defense wall in cyber environment. many studies were performed on d...

internet applications spreading and its high usage popularity result insignificant increasing of cyber-attacks. consequently, network security has becomea matter of importance and several methods have been developed for these attacks.for this purpose, intrusion detection systems (ids) are being used to monitor theattacks occurred on computer networks. data mining techniques, machinelearning, ne...

porosity is considered as an important petrophysical parameter in characterizing reservoirs, calculating in-situ oil reserves, and production evaluation. nowadays, using intelligent techniques has become a popular method for porosity estimation. support vector machine (svm) a new intelligent method with a great generalization potential of modeling non-linear relationships has been introduced fo...

different approaches have been proposed for feature selection to obtain suitable features subset among all features. these methods search feature space for feature subsets which satisfies some criteria or optimizes several objective functions. the objective functions are divided into two main groups: filter and wrapper methods.  in filter methods, features subsets are selected due to some measu...

segmentation and three‑dimensional (3d) visualization of teeth in dental computerized tomography (ct) images are of dentists’ requirements for both abnormalities diagnosis and the treatments such as dental implant and orthodontic planning. on the other hand, dental ct image segmentation is a difficult process because of the specific characteristics of the tooth’s structure. this paper presents ...

Vector controlled induction machine drives are increasingly used in industrial drive systems, but the drive performance often degrades with the machine parameter variations. In this paper, a modified vector control system is proposed to achieve decoupling when saturation and iron losses are taking into account. The simulated and experimental results of the modified controller are presented to v...