University of Tabriz

About: University of Tabriz is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Population & Nanocomposite. The organization has 12141 authors who have published 20976 publications receiving 313982 citations.

A hybrid support vector regression–firefly model for monthly rainfall forecasting

Abstract: Long-term prediction of rainfalls is one of the most challenging tasks in stochastic hydrology owing to the highly random characteristics of rainfall events. In this paper, a novel approach is adopted to develop a hybrid regression model for 1-month-ahead rainfall forecasting at two rain gauge locations (namely: Tabriz and Urmia stations), in northwest Iran. The approach is based on the integration of support vector regression (SVR) and firefly algorithm (FFA) that results in truthful rainfall forecasts. The proposed hybrid model was trained and validated using weak stationary state of monthly rainfall data obtained from the gauges. The efficiency results of the model were also cross-validated with those of stand-alone SVR- and genetic programming-based forecasting models developed as the benchmarks in this study. For both rain gauge locations, the results showed that the hybrid model significantly outperforms the benchmarks. With respect to the average efficiency results at the gauge locations, the FFA-induced improvement in the SVR forecasts was matched by an approximately 30% decrease in root-mean-square error and around 100% increase in Nash–Sutcliffe efficiency. Such a promising accuracy in the proposed model may recommend its application at monthly rainfall forecasting in the present semiarid region.

Aspects of design optimisation for switched reluctance motors

Abstract: Existing papers about suitable switched reluctance motor (SRM) airgap dimensions, which give optimum performance for doubly-salient structure motors, are reviewed and their deficiencies are mentioned. The recommendations of these papers cover a wide range of t/ lambda (tooth width/tooth pitch), which can optimise the performance of the SRM. Although some parts of these results are supported by the present work, some other parts may not be correct. A developed software package has been applied to the design of a single-tooth peg stator pole SRM. It is concluded that the optimum ratio of t/ lambda is between 0.33 and 0.40. Using the design constraints considered, the optimum split ratios (defined as the ratio of rotor diameter to stator outer core diameter) are estimated at between 0.57 and 0.63. The ratio between the back of core width and half of tooth width in the motor is estimated and it is found that the best range of this ratio is from 1.1 to 1.3. >

Bioactivity of malva sylvestris L., a medicinal plant from iran.

Abstract: Objective(s) Malva sylvestris L. (Malvaceae), an annual plant, has been already commonly used as a medicinal plant in Iran. In the present work, we evaluate some bioactivities of the plant extracts. Materials and Methods The aired-dried plant flowers and leaves were extracted by soxhlet apparatus with n-hexane, dichloromethane and methanol. The antimicrobial, cytotoxic, and phytotoxic of the plant extracts were evaluated using disk diffusion method, MTT, and Lettuce assays, respectively. Results Both flowers and leaves of M. sylvestris methanol extracts exhibited strong antibacterial effects against Erwinia carotovora, a plant pathogen, with MIC value of 128 and 256 µg/ml, respectively. The flowers extract also showed high antibacterial effects against some human pathogen bacteria strains such as Staphylococcus aureus, Streptococcus agalactiae, Entrococcus faecalis, with MIC value of 192, 200 and 256 µg/ml, respectively. The plant methanol extracts had relatively high cytotoxic activity against MacCoy cell line. Conclusion We concluded that Malva sylvestris can be candidated as an antiseptic, a chemopreventive or a chemotherapeutic agent.