http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
SSR Damping in Fixed-Speed Wind Farms Using Series FACTS Controllers
Mohammadpour, Hossein Ali,Islam, Md Moinul,Santi, Enrico,Yong-June Shin IEEE 2016 IEEE Transactions on Power Delivery Vol.31 No.1
<P>Subsynchronous resonance (SSR) damping in fixed-speed wind turbine generator systems (FSWTGS) by using two series flexible ac transmission system (FACTS) devices, the thyristor-controlled series capacitor (TCSC), and gate-controlled series capacitor (GCSC) are studied in this paper. The former is a commercially available series FACTS device, and the latter is the second generation of series FACTS devices using gate turnoff (GTO) or other gate-commuted switches. The GCSC is characterized by a fixed capacitor in parallel with a pair of antiparallel gate-commuted switches enabling rapid control of series impedance of a transmission line. It is shown that the SSR damping with a GCSC is limited to changing the resonance frequency, in comparison with a fixed capacitor, which may not be adequate to damp out the SSR. Therefore, a supplementary SSR damping controller (SSRDC) is designed for the GCSC. Moreover, it is proven that the GCSC equipped with a well-designed SSRDC can effectively damp the SSR in FSWTGS. In order to verify the effectiveness of the GCSC in SSR damping, its performance is compared with the TCSC, which is an existing series FACTS device. In addition, time-frequency analysis (TFA) is employed in order to evaluate and compare the SSR time-varying frequency characteristics of the GCSC and TCSC. The IEEE first benchmark model on SSR is adapted with an integrated FSWTGS to perform studies, and extensive simulations are carried out using PSCAD/EMTDC to validate the result.</P>
Mohammadpour, Mahdis,Bakhshalian, Neema,Shahab, Shahriar,Sadeghi, Shaya,Ataee, Mona,Sarikhani, Soodeh Korean Academy of Oral and Maxillofacial Radiology 2014 Imaging Science in Dentistry Vol.44 No.2
Purpose: Vertical root fracture (VRF) is a common complication in endodontically treated teeth. Considering the poor prognosis of VRF, a reliable and valid detection method is necessary. Cone beam computed tomography (CBCT) has been reported to be a reliable tool for the detection of VRF; however, the presence of metallic intracanal posts can decrease the diagnostic values of CBCT systems. This study evaluated and compared the effects of intracanal stainless steel or titanium posts on the sensitivity, specificity, and accuracy of VRF detection using a NewTom VG CBCT system. Materials and Methods: Eighty extracted single-rooted teeth were selected and sectioned at the cemento-enamel junction. The roots were divided into two groups of 40. Root fracture was induced in the test group by using an Instron machine, while the control group was kept intact. Roots were randomly embedded in acrylic blocks and radiographed with the NewTom VG, both with titanium and stainless steel posts and also without posts. Sensitivity, specificity, and accuracy values were calculated as compared to the gold standard. Results: The sensitivity, specificity, and accuracy of VRF diagnosis were significantly lower in teeth with stainless steel and titanium posts than in those without posts. Interobserver agreement was the highest in teeth without posts, followed by stainless steel posts, and then titanium posts. Conclusion: Intracanal posts significantly decreased the VRF diagnostic values of CBCT. The stainless steel posts decreased the diagnostic values more than the titanium posts.
Tunable Morphology for Silica/Poly(acrylic acid) Hybrid Nanoparticles via Facile One-Pot Synthesis
Maryam Mohammadpour Nazarabady,Gholam Ali Farzi 한국고분자학회 2016 Macromolecular Research Vol.24 No.8
Synthesis of the hybrid nanoparticles through simultaneous polymerization of organic monomer and solgel process of the inorganic precursor is a promising subject for creating new materials. Herein, an efficient one-pot synthesis method using the simultaneous sol-gel process with free radical polymerization technique reports the tunable morphology for silica/ poly(acrylic acid) (PAA) hybrid nanoparticles in which tetraethoxysilane (TEOS) and acrylic acid were used as inorganic and organic precursors, respectively. To achieve the best conditions for a simultaneous synthesis, the most important parameters such as pH, TEOS concentration, AA/TEOS ratio, surfactant concentration and temperature were adopted with respect to particle size. It is experimentally demonstrated that the reaction temperature is the most influential parameter affecting the particle size of hybrid nanoparticles. In addition, transmission electron microscopy images revealed that, the tunable morphology of hybrid nanoparticles from the organic-inorganic core-shell to organic and inorganic heterodimer nano(semi)spheres can be achieved by controlling the concentration of TEOS.
Ethnic and traditional Iranian rice-based foods
Vahid Mohammadpour Karizaki 한국식품연구원 2016 Journal of Ethnic Foods Vol.3 No.2
Background: Iranian national cuisine is very diverse and nutritious. A rice-based diet is commonly used by all people throughout the country. The current work aimed at documenting the ethnic and traditional rice-based foods prepared and consumed in Iran. Methods: The data were collected by individually interviewing people from 15 cities in five districts of Iran (north, south, west, east, and central parts), as well as searching literature and scientific sources. Results: A list of 100 ethnic and traditional rice-based foods of Iranian cuisine is presented in three categories: main meals, soups/pottages, and sweets/desserts. Conclusion: The main ingredient of traditional and ethnic Iranian foods is rice. Iranian people develop many ways to create and consume rice-based foods.
Experimental determination of void fraction in surface aeration using image processing technique
Amir Mohammadpour,Mohammad Ali Akhavan-Behabadi,Masoud Ebrahimzadeh,Pedram Hanafizadeh,Mehrdad Raisee 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.6
In this paper, a new method for determination of void fraction in surface aeration process is presented and discussed. The proposedmethod is based on the image processing technique. The experimental setup has been designed to create various surface aeration conditionsin the water. Void fraction has been calculated for the wide range of water height, impeller immersion depth and rotational speed. Experiments have been performed in an open cubic tank with side length of 60 cm, equipped with one Rushton disk turbine. Moreover,the void fraction has been measured with level gauge method. The results showed that the image processing technique provides moreaccurate results than the level gauge measurements for void fraction calculation in surface aeration especially in low void fraction aeration. In addition, the experimental data revealed that increase in impeller immersion depth and rotational speed increase void fraction andoxygen transfer rate in surface aeration process.
Evaluating Performance of Intrusion Detection System using Support Vector Machines : Review
Leila Mohammadpour,Mehdi Hussain,Alihossein Aryanfar,Vahid Maleki Raee,Fahad Sattar 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.9
The basic task in intrusion detection system is to classify network activities as normal or abnormal while minimizing misclassification. In literature, various machine learning and data mining techniques have been applied to Intrusion Detection Systems (IDSs) to protect the special computer systems, vulnerable traffics cyber-attacks for computer networks. In addition, Support Vector Machine (SVM) is applied as the classification techniques in literature. However, there is a lack of review for the IDS method using SVM as the classifier. The objective of this paper is to review the contemporary literature and to provide a critical evaluation of various techniques of intrusion detection using SVM as classifier. We analyze and identify the strengths and limitations of various SVM usages as classifier in IDS systems. This paper also highlights the usefulness of SVM in IDS system for network security environment with future direction.
Zahra Mohammadpour,Hamid R. Zare 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.4
Nickel–tungsten multi-walled carbon nanotubes (Ni–W/MWCNTs) nanocomposite coatings were co-electrodeposited inthe ammonium-free bath by means of constant direct current coulometry. The results indicate that the amount of MWCNTsincorporated into the nanocomposite coatings has a key role in the improvement of their microhardness and corrosion resistance. The corrosion behavior of the coatings was evaluated using potentiodynamic polarization and electrochemical impedancespectroscopy methods in three corrosive media of 3.5 wt% NaCl, 1.0 M NaOH, and 0.5 M H 2 SO 4 . The experimentaldata of the corrosion current density (j corr ), corrosion rate (CR), the polarization resistance (R p ), and microhardness indicatethat the presence of MWCNTs in coatings improves the quality of those coatings. The surface morphology of the coatingsand the elemental analysis data were obtained by scanning electron microscopy and energy dispersive X-ray microanalysisrespectively. As the results showed, the coatings were uniform and crack-free in the presence of 5.3 wt% carbon. Also, amicrohardness test revealed that the nanocomposite coating containing 5.3 wt% carbon obtained in an ammonium-free bathwhich provided the higher content of tungsten had the highest hardness value among others.