299 research outputs found
114 - Mahsa Ghorbani
No full textStock price prediction is one of the most challenging problems in finance and is receiving considerable attention from researchers. The literature provides strong evidence that prices can be predicted from past price data as well as other fundamental and macroeconomic variables. We propose a filtering operation using covariance information in order to predict future stock prices. We use daily historical price data for Generals Electric Company to illustrate our method, which shows promising results in terms of the estimation performance and volatility
Negative-Sequence Network Based Fault Location Scheme for Double-Circuit Multi-Terminal Transmission Lines
No full textThe fault resistance and infeeded currents from tapped transmission lines are the two main challenges to establish correct fault location estimation in multi-terminal transmission lines. Also, fault location estimation in double-circuit lines is more complicated than single-circuit lines due to the effect of mutual coupling and inter-circuit faults. This paper proposes a negative-sequence network-based method to estimate the fault location of double-circuit multi-terminal transmission lines. In the presented method, signals are measured in the relay location and then, communication links are not required as it uses only one end measurements. Also, in conventional distance relays, six elements are needed to calculate the fault location in all types of faults. Furthermore, in this method, by using only one element for each transmission line, accurate fault location can be estimated. Also, high fault resistance, mutual coupling, and infeeded currents from tapped transmission lines do not have impact on the performance of the presented scheme. To investigate the effects of the line shunt capacitances on the proposed method, a PI model of the transmission lines is used in all the investigations. Simulation results carried out using MATLAB software indicate that the proposed scheme is able to produce excellent performance for the fault location estimation. - 2018 IEEE.Manuscript received August 30, 2018; revised November 30, 2018 and February 24, 2019; accepted March 9, 2019. Date of publication March 18, 2019; date of current version May 22, 2019. This work was supported by the National Priorities Research Program under Grant 11S-1125-170027 from the Qatar National Research Fund (a member of Qatar Foundation). Paper no. TPWRD-00960-2018. (Corresponding author: Amir Ghorbani.) A. Ghorbani is with the Department of Electrical Engineering, Islamic Azad University, Abhar 4561934367, Iran (e-mail:,[email protected]).Scopu
Assessment of spinal cord abnormalities and its related factors in male students of Islamic Azad University at Semnan
No full textBackground and aimDecreased mobility and physical activity are threatening factors of health and spinal cord as the basic axis of the body is of critical importance in this regard because any injury of deformity of it can cause body malfunction. The aim of this study was to assess abnormalities of spinal cord and some of their related factors in male students of Islamic Azad University at Semnan. Materials and methods In this descriptive study, 240 students in their Physical Education Course 1 took part in the study. New York Test Posture Screen validated and made reliable by content and test-retest (r=0.80) methods respectively as well as Matiyas Test were applied for the assessment. A 3-grade scale including good, fair and poor was used for classification and those classified as good were regarded normal and those classified as fair or poor were considered as abnormal. Data were analyzed by SPSS 14. Findings 91.3% of the subjects suffer at least from one of spinal cord abnormalities. The most common condition was falling shoulders (74.2%) and the least frequent was pelvic obliquity (2.5%). Matiyas test was negative in 58.8% (not able to remain in requested position). 33.3% was overweight and obese in terms of body mass index (BMI). ConclusionThe results showed that the prevalence of spinal cord abnormalities in the subjects was very high (91.3%) mostly due to poor mobility, weakness in the muscles of upper extremities particularly those holding the spine and lack of exercise. Thus, planning for physical activities and exercise in the leisure time of students seems essential. Keywords: Spinal cord, Spinal cord abnormalities, Exercise, Scoliosis. *Corresponding Author: Mohammad Rashidi. Dept. of Physical Education, Islamic Azad University, Semnan, Iran. E-mail: [email protected]
An Accurate Non-Pilot Scheme for Accelerated Trip of Distance Relay Zone-2 Faults
No full textThe delayed operation of distance relays zone-2 element for the faults at the end of the line is excessive. It reduces the fault clearing speed and therefore, is one of the main factors that can endanger power system stability. This paper proposes an impedance-based scheme for discrimination between the last 20% of the line length faults and the adjacent line faults, which are covered by the relay zone-2. The suggested non-pilot scheme uses a modified fault location formula for the accelerated zone-2 operation of distance relays. The negative- and zero-sequence components of local signals are utilized to calculate the accurate fault location after the remote circuit breaker (CB) operation. The proposed algorithm is independent of fault resistance, power flow direction, pre-fault condition, and it can clearly distinguish internal faults from the adjacent line faults. Simulation results show that the proposed method can identify the remote CB operation and thus can accelerate the tripping of zone-2 within a very short time for different fault locations, fault types, fault resistances, and load angles. Also, accurate fault location has been achieved under all simulation conditions. 1986-2012 IEEE.Manuscript received December 7, 2019; revised March 12, 2020, May 20, 2020, and July 1, 2020; accepted July 3, 2020. Date of publication July 7, 2020; date of current version May 21, 2021. This work was supported in part by the National Priorities Research Program under Grant 11S-1125-170027, and in part by the Qatar National Research Fund (a member of Qatar Foundation). (Corresponding author: Amir Ghorbani.) Amir Ghorbani is with the Department of Electrical Engineering, Ab-har Branch, Islamic Azad University, Abhar 4561897594, Iran (e-mail: [email protected]).Scopus2-s2.0-8509911653
Effective factors on Tendency of Students Tabriz Universities to Join Entrepreneur Cooperatives
No full textOne of the general guidelines for reducing unemployment is creating jobs and participating people in economic activities and developing cooperatives. Enabling cooperative sector by relying on the academic capability of university graduates will increasingly lead to presence in global markets and opening economic borders. So among the three sectors of cooperation, public and private, cooperative companies can be an appropriate method for employment and attraction of graduates. The current study investigates the tendency of student groups to join Entrepreneur cooperatives and factors affecting this phenomenon in two universities of Islamic Azad University of Tabriz and Public University of Tabriz. For this purpose, after familiarity with cooperatives and related theories, sample size of 378 (Islamic Azad University of Tabriz) and 376 (University of Tabriz) was determined using the Cochran formula person with a stratified, systematic and random sampling method. Survey and documents method were used for gathering data. Data were processed with SPSS software.
The results show that there is a significant relationship between independent variables (social participation, social trust, social cohesion, needs satisfaction and individual characteristics) and dependent variable (tendency of student groups to join entrepreneur cooperatives). There is significant difference (with reliability of 99%) between the two groups (students of Azad and National University) in terms of tendency to join entrepreneur cooperatives. This tendency is higher among Azad university students in comparison with public university students
The Relation between Treated Maternal Urinary Tract Infection and Adverse Maternal, Prenatal Outcomes in Pregnant Women of Ardabil, Iran
No full textBackground and Objective: Urinary tract infection is one of the most common bacterial infections during pregnancy and has also been implicated as a risk factor for adverse maternal and prenatal outcomes. The aim of our study was to determine the relation between maternal urinary tract infection and adverse maternal, prenatal outcomes in pregnant women of Ardabil, Iran.
Material and Methods: This retrospective-case-control study was conducted on prenatal file records of pregnant women in Ardabil (2011). The pregnant women who had a positive urine culture in their prenatal files (N= 211) were considered as a case group and 232 ones without urinary tract infection as a control. Using a research- made questionnaire, the data related to present pregnancy and prenatal information was collected and analyzed by KrusKal Wallis, Chi- Square and Fisher statistical tests.
Results: Maternal age of under 25 (%61.6 vs. 56.5), body mass index of more than 30 (%18.3 vs. 15.6), primigravida (%55 vs. 48.8), hypertension (%2.4 vs. 1.3), hyperemesis Gravidarum (%14.8 vs. 12.6), frequency and dysuria (%1.9 vs. 0.9), low birth weight (%95.4 vs. 93.2), congenital malformation (%3.5 vs. 1.8), artificial milk feeding (%6.5 vs. 2.7), neonatal death (%0.9 vs. 0.0) are higher in urinary infection group, however the differences are not statistically significant. Other maternal and prenatal adverse outcomes such as diabetes, pre-eclampsia , hemoglobin level, prematurity, abortion and stillbirth have not significant relation with urinary infection.
Conclusion: Because of low level of adverse maternal or prenatal outcomes reported in our study, we conclude that screening and treatment of urinary tract infection in Ardabil health service is appropriate; therefore, no change is needed for present screening or treatment processes
Designing a Qualitative Model of Knowledge Creation with an Innovative Approach in North Khorasan Islamic Azad Universities
No full textObjective: Taking into account the critical significance of generating innovative concepts and the necessity for universities to embrace fresh ideas and inventive theories, it is anticipated that academic institutions and research environments will transcend conventional frameworks and adjust to the evolving demands of society, thereby establishing an appropriate foundation for the generation of knowledge. The objective of the present study is to formulate a knowledge creation model employing an open innovation paradigm within the Islamic Azad Universities of North Khorasan.
Methods: This investigation employs a qualitative methodology. The targeted demographic for this study comprised scholarly experts who possessed insights in the domains of executive management and human resources, had attained a university education, and were selected through purposive sampling techniques.
Results: The results of the study revealed that the proposed knowledge creation model is comprised of seven dimensions, which include socialization, externalization, content factors, composition, structural factors, internalization, and cognitive aspects.
Conclusions: Overall, the knowledge creation model featuring redefined innovation presented in this research demonstrates substantial validity and can effectively inform the policies and strategies pertaining to knowledge generation within universities and institutions of higher education
Molecularly Imprinted Polymers (MIP) for Selective Solid Phase Extraction of Celecoxib in Urine Samples Followed by High Performance Liquid Chromatography
No full textIn this study, for the analysis of human urine samples, a novel method explained for the determination of celecoxib, a nonsteroidal anti-inflammatory drug (NSAID), using molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography (HPLC). The synthesis of the MIP was performed by precipitation polymerization in methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), chloroform, 2,2′-azobisisobutyronitrile (AIBN) and celecoxib as the functional monomer, cross-linker monomer, solvent, initiator and target drug, respectively. The celecoxib imprinted polymer was utilized as a specific sorbent for the solid phase extraction (SPE) of celecoxib from samples. The molecularly imprinted polymer (MIP) performance was compared with the synthesized non-molecularly imprinted polymer (NIP). Scanning electron microscopy (SEM), FT-IR spectroscopy, UV-VIS spectrophotometry and thermogravimetric analysis (TGA/DTG) were used for characterizing the synthesized polymers. Moreover, the MISPE procedure parameters such as pH, eluent solvent flow rate, eluent volume and sorbent mass that probably inï‚uence the extraction process have been optimized to achieve the highest celecoxib extraction efïciency. The relative standard deviation (RSD %), recovery percent, limit of detection (LOD) and limit of quantification (LOQ) of this proposed method were 1.12%, 96%, 8 µg L-1 and 26.7 µg L-1, respectively. The proposed MISPE-HPLC-UV method can be used for the separation and enrichment of trace amounts of celecoxib in human urine and biological samples
Hybrid additive manufacturing of an electron beam powder bed fused Ti6Al4V by transient liquid phase bonding
No full textHybrid Additive Manufacturing (HAM) is a production strategy enhancing the flexibility of the already versatile Additive Manufacturing (AM) techniques. AM of Ti6Al4V, on the other hand, has been of great interest to numerous research works, thanks to the unique corrosion, biomedical and mechanical properties of the alloy. Hence, this research marks the first report on the HAM of Ti6Al4V by Transient Liquid Phase (TLP) bonding of an Electron Beam Powder Bed Fused (EB-PBF) sample to a conventional one. A copper interlayer was used for bonding, and the TLP process was performed at 890 degrees C and 970 degrees C for 60 min. Shear strength test was carried out and the results showed the highest shear strengths of 579.3 and 662.5 MPa for TLP bonding at 890 degrees C and 970 degrees C, respectively. By increasing the bonding temperature to 970 degrees C, no Cu-rich phases were observed in the microstructure, as opposed to the 890 degrees C samples, and a complete isothermal solidification without intermetallic phases was achieved. Moreover, the 970 degrees C TLP sample was featured with a much better microstructural integrity and homogeneity in both the base metals and the bonded zone. TLP bonding at 970 degrees C resulted in a more ductile fracture surface than that bonded at 890 degrees C. The strong differences between the two TLP bonds were primarily attributed to the faster diffusion rate of elements along the joint and base metal at higher temperatures. (C) 2022 The Author(s). Published by Elsevier B.V
The Relationship Between Self-Regulated Learning Components and Achievement Motivation in Students of Islamic Azad University, Tehran Medical Branch
No full textBackground: It is nearly a century that psychologists strive to identify the predictors of academic achievement. Objectives: The present study aimed at investigating the relationship between selfregulated learning, achievement motivation, and academic achievement, and obtaining results to create appropriate strategies to increase motivation and improve learning in students to help them with academic achievement and empowerment. Method: The present c ross s ectional s tudy w as c onducted i n t he a cademic y ear of 2016-2017. A total of 190 students of Islamic Azad University, Tehran Medical Branch, were selected by the convenience sampling method and completed the motivated strategies for learning (MSLQ) and achievement motivation questionnaires. Data were analyzed using the Pearson correlation coefficient in SPSS. Results: There w as a s ignificant re lationship be tween ac hievement mo tivation an d the components of self-efficacy, in trinsic go al or ientation, he lp-seeking, an d ti me management (P <0.001). Students getting higher scores on MSLQ also got higher scores on self-efficacy, time management, and intrinsic goal orientation (P <0.001). Conclusion: According to the study results, to empower medical students in academic achievement, their self-efficacy, time management skills, and goal orientation should be improved. Keywords: Self-Regulated Learning, Achievement Motivation, Medical Student
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