Showing 11 results for mahjoob
Volume 5, Issue 3 (9-2017)
Abstract
Aim: Type 2 diabetes is a preventable disease and can be prevented in people at risk by doing appropriate interventions and selecting new educational practices. Mobile learning is one of the modern educational techniques used for providing opportunities for the transmission of information, as well as strengthening and improving lifelong learning for learners. We aimed to investigate mobile learning impact on blood glucose control in people with type 2 diabetes referred to Ahvaz Diabetes Consultation Center.
Methods: This semi-experimental study was conducted on 60 samples selected by the random stratified sampling method. The subjects were divided into two groups: experimental group and control group. In this study, data were measured using the fasting blood sugar, DPS software and the demographic questionnaire. Before the start of the intervention, demographic profile and fasting blood sugar level were recorded in the relevant form. A designed software program was loaded on the cell phones of the experimental group. After three weeks, the blood samples were taken. Data were analyzed using the descriptive-analytical statistics tests. The significance level was considered to be less than 0.05.
Findings: The findings showed that the positive effect of implementation the training program by mobile learning method was statistically significant in the control of blood sugar in the experimental group (P<0.001).
Conclusion: Mobile learning is one of the modern educational practices that can be used to control blood glucose in people at a higher risk of type 2 diabetes. The use of educational technology can be considered as a good way to help the improvement of the health outcomes and behavior of people at risk for diabetes.
Volume 6, Issue 2 (6-2017)
Abstract
The functional response of the egg parasitoid, Trissolcus vassilievi (Nees) (Hym., Scelionidae), on eggs of the sunn pest, Eurygaster integriceps Put. (Hem., Scutelleridae) was investigated at six constant temperatures (12, 15, 20, 25, 28 and 32 °C) for 8 hours. Using logistic regression, a type III functional response was determined for T. vassilievi at the two temperatures 15 and 32 °C. Any functional response was not detected at other temperatures. The Hassells’ type III model was used for estimating searching efficiency (a) and handling time (Th). At 32 °C the highest attack rateand the lowest handling time was recorded 0.2029 per hour and 0.1856 hour, respectively. Results show that the parasitoid can be used in the pest management programs at low and high temperatures.
Volume 12, Issue 4 (fall 2021)
Abstract
Breast cancer is the leading cause of cancer-related mortality among women worldwide. In Iran, breast cancer ranks first among cancers diagnosed in women comprising 24.4% of all malignancies. Currently, the large number of etiological factors and the complexity of breast cancer present challenge for prevention and treatment. Breast cancer tumorigenesis can be described as a multi-step process in which a normal cell undergoes malignant transformation to a fully developed tumor through accumulations of genetic and epigenetic changes, on the other hand, Several studies indicated the signaling pathways role in Breast cancer. EGFR gene has been shown to be overexpressed in breast cancer .Dimerization of EGFR/HER2 induces breast cancer progression via activation of PI3K/AKT signaling cascade
MicroRNAs are endogenous, small non-coding RNAs that regulate gene expression at the transcriptional and posttranscriptional level. MicroRNAs pair with partially complementary sites in the 3′untranslated regions (UTRs) of target mRNAs, leading to translational repression and/or mRNA degradation. They play important roles in several cellular processes, such as proliferation, differentiation, apoptosis, and development, by simultaneously controlling the expression level of hundreds of genes. Here we demonstrated the tumor suppression effect of miR-1226-3p in Breast cancer by targeting EGFR oncogene.
Esmaeel Bagherpour-Ardakani, Mohammad Reza Hairi Yazdi, Mohammad mahjoob,
Volume 15, Issue 4 (6-2015)
Abstract
This paper is devoted to sensor fault detection in linear systems with observer-based approach. It is assumed that the system has linear dynamics with the presence of uncertainties. The uncertainties are modeled as unknown input (disturbance), while it is assumed that the well-known observer matching condition is not necessarily satisfied. To decouple the unknown-input effects, and distinguish their effects from the fault effects, an equivalent dynamic system is proposed which is independent from the unknown input. The equivalent system is constructed by the use of a unique integral filter. The introduced integral-filter, which is called buffer-based integral filter in this paper, has frequency response similar to the low-pass filter. Hence, the capability of noise filtration will also be provided. The construction of the equivalent dynamic system is achieved from the use of multiple successive buffer-based integrators and the number of successive filters is related to relative degree between the unknown input and the sensor output. Then, an unknown input observer is proposed for the equivalent system, and therefore, a disturbance-decoupled and fault-sensitive with exponential-convergent toward-zero residual vector will be generated. Although, the generated residual vector can be used for sensor and actuator fault diagnosis problems; however, the focus of this paper will be on the sensor fault detection. Finally, the applicability of the proposed method will be investigated via simulation of a simple inverted-pendulum on a horizontal-moving cart.
Mohammad Ali Tofigh, Mohammad mahjoob, Moosa Ayati,
Volume 15, Issue 8 (10-2015)
Abstract
In this paper, modeling and design of a trajectory tracking control system for a novel multi-rotor UAV (Unmanned Aerial Vehicle) is developed. The UAV is similar to a quadrotor with an extra no feedback propeller which is added to center of vehicle. The additional rotor improves the ability of lifting heavier payloads, and anti-crosswind capability for quadrotor. For validation, the dynamic model is obtained via both Newton Euler and Lagrange approaches. The dynamical model is under actuated, nonlinear, and has strongly coupled terms. Therefore, an appropriate control system is necessary to achieve desired performance. The proposed nonlinear controller of this paper is an input-output feedback linearization companioned with an optimal LQR controller for the linearized system. The controller involves high-order derivative terms and turns out to be quite sensitive to un-modeled dynamics. Therefore, precise model of UAV is derived by considering actuator’s dynamics. To compensate the actuator’s dynamic and moreover, to avoid complexity in the controller, a second control loop is utilized. The obtained simulation results confirm that the proposed control system has a promising performance in terms of stabilization and position tracking even in presence of external disturbances.
Mohammad Ali Tofigh, Mohammad mahjoob, Seyed Mousa Ayati,
Volume 15, Issue 9 (11-2015)
Abstract
In this paper, modeling and tow type of nonlinear controller for trajectory tracking of a novel five-rotor UAV (Unmanned Aerial Vehicle) is developed. Because of the very simple structure and high maneuverability, quadrotors are one of the most preferred types of UAVs but the main problem of them is their small payload. In the proposed novel model, one propeller is added to the center of vehicle to improve the ability of lifting heavier payloads, and to excel anti-crosswind capability of quadrotor. The dynamic model is obtained via Newton Euler approach. The model is under actuated, nonlinear, and has strongly coupled terms. Also, two types of nonlinear controllers are presented. First one is a conventional input-output feedback linearization controller which involves high-order derivative terms and turns out to be quite sensitive to sensor noise as well as modeling uncertainty. Second controller is a BackStepping controller based on the hierarchical control strategy that yields easier controller. The obtained simulation results confirm that the performance of BackStepping controller is convenient in terms of stability, position tracking and it is robust in presence of disturbance.
Mohammad Ali Tofigh, Mohammad mahjoob, Moosa Ayati,
Volume 15, Issue 9 (11-2015)
Abstract
In this paper, modeling and feedback linearization controller for trajectory tracking of a novel six-rotor UAV (Unmanned Aerial Vehicle) is developed. Because of the very simple structure and high maneuverability, quadrotors are one of the most preferred types of UAVs but the main problem of them is their small payload. In the proposed novel model, two coaxial propellers are added to the center of vehicle to improve the ability of lifting heavier payloads, and to excel anti-crosswind capability of quadrotor, while the dynamic and steering principle is preserved. The dynamic model is obtained via Newton Euler approach. Model is under actuated, nonlinear, and has strongly coupled terms. Also, two types of nonlinear controllers are presented. First one is a conventional input-output feedback linearization controller which involves high-order derivative terms and turns out to be quite sensitive to sensor noise as well as modeling uncertainty. Second controller is a feedback linearization based on the hierarchical control strategy that yields easier controller. To compensate actuator’s dynamic and moreover, to avoid complexity of controller, a two-stage algorithm is utilized. The obtained simulation results confirm that the performance of hierarchical controller is more convenient in terms of position tracking and disturbance rejection than conventional controller.
Osve Jaddinia, Mohammad Reza Zakerzadeh, Mohammad mahjoob,
Volume 15, Issue 11 (1-2016)
Abstract
Today, due to ever-increasing demand for fast and precise movements and changes, along with small-scale actuations in many engineering fields, the use and efficiency of smart materials has increased in importance. Magnetic Shape Memory Alloy (MSMA) is one of the latest smart materials having both shape memory and magnetic properties. As a matter of fact, in normal room temperatures, it has magnetic field-induced strains far more than any other smart materials such as magnetostrictive, piezoelectric or electrostrictive materials and its frequency response is greater than thermal shape memory alloy. However, on the downside, asymmetric hysteresis is a property that constrains its widespread applications. Prandtl-Ishlinskii model is one of the powerful phenomenological models for simulating asymmetric, non-linear hysteresis used to simulate smart material behavior. In the present study, MSMA hysteresis behavior simulation has been investigated through a new approach using generalized Prandtl-Ishlinskii model. After identifying the model parameters, the study compares the predicted output with the experimental results. For validation the model, using different data, model accuracy has been checked and prediction error has been compared. The experimental results have approved the capability of the model in predicting the hysteresis behavior. Thanks to invertible and simplicity potential of the generalized Prandtl-Ishlinskii model, the inverse of model can be applied as a feedforward controller for compensating the hysteresis behavior. It should also be noted that all the experimental results have been yielded through using experimental set-up.
Volume 19, Issue 5 (12-2019)
Abstract
The presence of halite karst systems in dam reservoirs can be one of the crucial sources of pollutants for the water resources. Karstic regions are those with dissolving caves. If dam is constructed in the regions with reactive rocks it is likely to be endangered by karst phenomenon, dissolution and corrosion of current waters. construction of dams and reservoirs in these formations are associated with high risk. Comprehensive and accurate understanding of the salt dissolution processes facilitates the description of salt karst formations dissolution process in dam reservoirs.
This research was performed based on three basis: field studies, experimental investigation and numerical modeling. For determination of dissolution coefficient, the physical model of reservoir was built in form of trapezoidal channel and samples of salt rock in the reservoir were used in the physical model of karst formation. This model was implemented in different conditions and the results of dissolution amount and salt concentration were measured for different time scales. At the next stage, the physical model was simulated in numerical model for determining of dissolution coefficient. The numerical model ran with different dissolution coefficients and results were compared with experimental results. With this comparison and adaptation of results, the dissolution rate of halite karst determined and then used in the numerical simulation of main reservoir. With simulation of main reservoir using dissolution coefficient obtained from laboratory study, the effect of salt karst formation on reservoir’s water quality was analyzed. The influences of effective parameters such as dissolution rate, air temperature, discharge and relative humidity on the water quality of dam reservoir were studied along with carrying out a wide range of sensitivity numerical analysis. To this purpose, a versatile finite volume tool ‘MIKE’ was used. Using the experimental study and numerical simulation and implementation of results, the dissolution coefficient of salt karst formation was calculated about 0.2 cm/h. Numerical model results showed that early months of operation were not critical to the project and salt concentration in reservoir was in the range of 0.8 to 0.9 of allowable limit. But considering the changes occuring in reservoir’s conditions, the process of salinity distribution increases and salt concentration increases with time. By comparing the salt concentration in reservoir and in numerical model, it was found that the average error percentage of concentration values was about 13.65 percent and the numerical model showed the values lower than the reservoir in most times.
The sensitivity analysis of parameters affecting the salinity distribution, showed that these parameters have a significant impact on salinity distribution and salt concentration in reservoir. It was found that with 10 percent changes in studied parameters, dissolution rate with 21%, air temperature with18%, discharge with 21.1% and relative humidity with 6.1% caused changes in salt concentration of reservoir. According to the results it is evident that dissolution rate and discharge were the most important factors that influence the behavior of salinity distribution in dam reservoir.
Saeid mahjoob , Mostafa Nazemizadeh ,
Volume 23, Issue 10 (October 2023)
Abstract
In this article, the kinematic and dynamic analysis of a multi-bar drum mechanism is discussed using Adams software. At first, the modeling of the mechanism is done in the catia engineering software, and then the model is entered in the Adams software. Then, by determining the appropriate joints, the initial speed is given to the mechanism and THE MOTION OF the mechanism is simulated. A kinematic analysis of the mechanism is performed and results of speed and acceleration of the joints are presented. The performed design and simulation show the effectiveness of the mechanism.
Saeid mahjoob , Mostafa Nazemizadeh ,
Volume 23, Issue 10 (October 2023)
Abstract
Multi-bar collapsible drum mechanisms are used in various industries such as steel factories, tire factories, etc. In this article, the analysis of a collapsible multi-bar drum mechanism and its optimization is discussed using SAM software. At first, the modeling of the collapsible mechanism is carried out in Catia, and the motion analysis and possible interferences of the mechanism are evaluated. Then the mechanism is entered and analyzed in the SAM software. In this software, the position of the joints along with their movement path is determined, and therefore, it is possible to optimize the position of the mechanism joints in order to avoid interference of the parts.
