Forecasting Maximum Seasonal Temperature Using Artificial Neural Networks "Tehran Case Study"

Elham Fahimi Nezhad,Gholamabbas Fallah Ghalhari,Fateme Bayatani 한국기상학회 2019 Asia-Pacific Journal of Atmospheric Sciences Vol.55 No.2

The main purpose of this research is maximum temperature prediction using neural network techniques. For this purpose, 70%of the data were allocated for network training and 30% of the data were devoted for testing and validation. The most appropriate neural network structure for predicting Tehran maximum winter temperature is a model with three neurons in the input layer, and a hidden layer with 9 neurons and the use of a hyperbolic tangent function in the hidden layer, that is, 3–9-1 arrangement in which the root mean of square error, correlation coefficient and the mean of absolute error for the training phase and the testing phase are respectively 0.001, 0.997, 0.61 and 0.104, 0.997, 0.311. The determination coefficient and correlation coefficients for both training and testing periods equal 0.99 and 0.99 and the correlation coefficient is significant at the level of 1%.

A New Approach for Applying a Non-conductive Mandrel in Electroforming of Complex Bellows-Shape

Pouya Fahimi Azad,Hamid Montazerolghaem 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.6

In this research, innovatively a flexible non-conductive polymer mandrel by applying graphite was used instead of conventional metal mandrels. To achieve a uniform shell thickness, a helical anode instead of usual flat anode and pulse reverse current instead of constant current were utilized. In this research, the effects of parameters such as current, pulse-forward time, pulse-reverse time on copper bellows-shape parts using pulse-reverse current in order to obtain proper thickness uniformity and hardness was investigated. To optimize the electroforming parameters, Response Surface Method (RSM) was applied. The optimum pulse-reverse and pulse-forward time for the set of parameters used in the experiments was determined to be I = 2A, TF = 8 ms and TR = 3.5 ms. Consequently, results showed that the type of current had a dominant effect on the uniformity of the copper bellows-shape parts on the non-conductive mandrel and the pules-reverse time played a significant role in obtaining efficient mechanical properties.

In silico analysis of an envelope domain III-based multivalent fusion protein as a potential dengue vaccine candidate

Hossein Fahimi,Majid Sadeghi-Zadeh,Mahshid Mohammadipour 대한백신학회 2016 Clinical and Experimental Vaccine Research Vol.5 No.1

Purpose: Dengue virus infection is now a global problem. Currently, there is no licensed vaccine or proven antiviral treatment against this virus. All four serotypes (1-4) of dengue virus can infect human. An effective dengue vaccine should be tetravalent to induce protective immune responses against all four serotypes. Most of dengue vaccine candidates are monovalent, or in the form of physically mixed multivalent formulations. Recently envelope protein domain III of virus is considered as a vaccine candidate, which plays critical roles in the most important viral activities. Development of a tetravalent protein subunit vaccine is very important for equal induction of immune system and prevention of unbalanced immunity. Here, we have presented and used a rational approach to design a tetravalent dengue vaccine candidate. Materials and Methods: We designed a multi domain antigen by fusing four consensus domain III sequences together with appropriate hydrophobic linkers and used several types of bioinformatics software and neural networks to predict structural and immunological properties of the designed tetravalent antigen. Results: We designed a tetravalent protein (EDIIIF) based on domain III of dengue virus envelope protein. According to the results of the bioinformatics analysis, the constructed models for EDIIIF protein were structurally stable and potentially immunogenic. Conclusion: The designed tetravalent protein can be considered as a potential dengue vaccine candidate. The presented approach can be used for rational design and in silico evaluation of chimeric dengue vaccine candidates.

Time-history analysis based optimal design of space trusses: the CMA evolution strategy approach using GRNN and WA

Kaveh, A.,Fahimi-Farzam, M.,Kalateh-Ahani, M. Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.3

In recent years, the need for optimal design of structures under time-history loading aroused great attention in researchers. The main problem in this field is the extremely high computational demand of time-history analyses, which may convert the solution algorithm to an illogical one. In this paper, a new framework is developed to solve the size optimization problem of steel truss structures subjected to ground motions. In order to solve this problem, the covariance matrix adaptation evolution strategy algorithm is employed for the optimization procedure, while a generalized regression neural network is utilized as a meta-model for fitness approximation. Moreover, the computational cost of time-history analysis is decreased through a wavelet analysis. Capability and efficiency of the proposed framework is investigated via two design examples, comprising of a tower truss and a footbridge truss.

Optimum design of steel frame structures considering construction cost and seismic damage

A. Kaveh,M. Fahimi-Farzam,M. Kalateh-Ahani 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.16 No.1

Minimizing construction cost and reducing seismic damage are two conflicting objectives in the design of any new structure. In the present work, we try to develop a framework in order to solve the optimum performance-based design problem considering the construction cost and the seismic damage of steel moment-frame structures. The Park-Ang damage index is selected as the seismic damage measure because it is one of the most realistic measures of structural damage. The non-dominated sorting genetic algorithm (NSGA-II) is employed as the optimization algorithm to search the Pareto optimal solutions. To improve the time efficiency of the proposed framework, three simplifying strategies are adopted: first, simplified nonlinear modeling investigating minimum level of structural modeling sophistication; second, fitness approximation decreasing the number of fitness function evaluations; third, wavelet decomposition of earthquake record decreasing the number of acceleration points involved in time-history loading. The constraints of the optimization problem are considered in accordance with Federal Emergency Management Agency\'s (FEMA) recommended seismic design specifications. The results from numerical application of the proposed framework demonstrate the efficiency of the framework in solving the present multi-objective optimization problem.

Beneficial effects of Teucrium polium hydroalcoholic extract on letrozole-induced polycystic ovary syndrome in rat model

Zeynab Khosrowpour,Shirin Fahimi,Fateme Jafari,Mojgan Tansaz,Shamim Sahranavard,Mehrdad Faizi 대한산부인과학회 2023 Obstetrics & Gynecology Science Vol.66 No.2

ObjectivePolycystic ovary syndrome (PCOS) is an endocrine disorder that disrupts the menstrual cycle and causes infertility. Considering the increasing use of medicinal plants, the present study aimed to evaluate the effects of Teucrium polium L. on letrozole-induced PCOS in female rats. MethodsSix groups of rats (n=7 each) were evaluated. The control group received 1% carboxy methyl cellulose as vehicle, while the five other groups received letrozole 1 mg/kg orally for 21 days. After PCOS induction, the rats were orally administered T. polium extract (50, 100, and 200 mg/kg) or metformin (200 mg/kg) for 28 days. Subsequently, body and ovarian weights and serum levels of follicle stimulating hormone, luteinizing hormone (LH), estradiol, progesterone, and testosterone were measured. Finally, the ovarian tissues were isolated for histological examination. ResultsThere were no significant changes in weekly body weight in any group. After 21 days of letrozole administration, PCOS induction was confirmed by estrous cycle irregularities and increased LH and testosterone levels. After treatment with the hydroalcoholic extract of T. polium, testosterone and LH levels were significantly reduced in all groups (P<0.05). Histological studies of ovaries in the metformin and T. polium groups exhibited normal follicular development with fewer and smaller cystic follicles than those in the PCOS group. ConclusionThe hydroalcoholic extract of T. polium improves serum levels of sex hormones, restores ovarian morphology in PCOS-induced rats, and is a good candidate for further clinical trials.

Time-history analysis based optimal design of space trusses: the CMA evolution strategy approach using GRNN and WA

A. Kaveh,M. Fahimi-Farzam,M. Kalateh-Ahani 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.3

In recent years, the need for optimal design of structures under time-history loading aroused great attention in researchers. The main problem in this field is the extremely high computational demand of time-history analyses, which may convert the solution algorithm to an illogical one. In this paper, a new framework is developed to solve the size optimization problem of steel truss structures subjected to ground motions. In order to solve this problem, the covariance matrix adaptation evolution strategy algorithm is employed for the optimization procedure, while a generalized regression neural network is utilized as a meta-model for fitness approximation. Moreover, the computational cost of time-history analysis is decreased through a wavelet analysis. Capability and efficiency of the proposed framework is investigated via two design examples, comprising of a tower truss and a footbridge truss.

Prevalence of Oxaliplatin-induced Chronic Neuropathy and Influencing Factors in Patients with Colorectal Cancer in Iran

Shahriari-Ahmadi, Ali,Fahimi, Ali,Payandeh, Mehrdad,Sadeghi, Masoud Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: The chemotherapeutic agent oxaliplatin can cause acute and chronic forms of peripheral neuropathy. The aim of this study was to evaluate the incidence of chronic neuropathy and its risk factors in colorectal cancer (CRC) patients treated with FOLFOX or XELOX regimens in the Oncology Ward of Hazrate-Rasoul Hospital in Tehran. Materials and Methods: A total of 130 patients with CRC were entered into our study, aged over 18 years, without history of receiving other neurotoxic agents or other predisposing factors such as diabetes or neurologic diseases and kidney and liver dysfunction. For the FOLFOX regimen, patients received oxaliplatin, 85mg/m2, every 2 weeks for 12 courses and with the XELOX regimen, oxaliplatin was $130mg/m^2$, every 3 weeks for 8 courses. Based on Common Toxicity Criteria (CTC or NCI-CTC v.3), the patients were divided into 5 groups (grades) based on the severity of their symptoms. Results: Fifty-seven patients (43.8%) were male and 73(56.2%) female. Some 19 patients (14.7%) had BMI<20, 97(74.6%) were between 20-25 and 14 (10.8%) ${\geq}25$. In 105 patients (80.7%) neuropathy was found. There was significant correlation between BMI, hypomagnesaemia and especially, severity of anemia in patients with neuropathy compared to those without. Conclusions: Oxaliplatin regimens can induce chronic neuropathy in CRC patients, with anemia, high BMI and hypomagnesaemia as risk factors that can predispose to this kind of neurotoxicity.

Constructability optimal design of reinforced concrete retaining walls using a multi-objective genetic algorithm

A. Kaveh,M. Kalateh-Ahani,M. Fahimi-Farzam 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.47 No.2

The term “constructability” in regard to cast-in-place concrete construction refers mainly to the ease of reinforcing steel placement. Bar congestion complicates steel placement, hinders concrete placement and as a result leads to improper consolidation of concrete around bars affecting the integrity of the structure. In this paper, a multi-objective approach, based on the non-dominated sorting genetic algorithm (NSGA-II) is developed for optimal design of reinforced concrete cantilever retaining walls, considering minimization of the economic cost and reinforcing bar congestion as the objective functions. The structural model to be optimized involves 35 design variables, which define the geometry, the type of concrete grades, and the reinforcement used. The seismic response of the retaining walls is investigated using the well-known Mononobe-Okabe analysis method to define the dynamic lateral earth pressure. The results obtained from numerical application of the proposed framework demonstrate its capabilities in solving the present multi-objective optimization problem.

Thyristor-Based Resonant Current Controlled Switched Reluctance Generator for Distributed Generation

Emadi Ali,Patel Yogesh P.,Fahimi Babak The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.1

This paper covers switched reluctance generator (SRG) and its comparison with induction and synchronous machines for distributed generation. The SRG is simple in design, robust in construction, and fault tolerant in operation; it can also withstand very high temperatures. However, the performance and cost of the SRG power electronics driver are highly affected by the topology and design of the converter. IGBT and MOSFET based converters are not suitable for very high power applications. This paper presents thyristor-based resonant converters which are superior candidates for very high power applications. Operations of the converters are analyzed and their characteristics and dynamics are determined in terms of the system parameters. The resonant converters are capable of handling high currents and voltages; these converters are highly efficient and reliable as well. Therefore, they are suitable for high power applications in the range of 1MW or larger for distributed generation.