Uncertain Polytopic LPV Modelling of Robot Manipulators and Trajectory Tracking

Mohammad Bagher Abolhasani Jabali,Mohammad Hosein Kazemi 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.2

This research work proposes a full state systematic feedback control design method for some classes ofnon-linear systems which are forced to follow a specific desired trajectory, such as robotic systems, using uncertainpolytopic linear parameter-varying (LPV) modelling approach. An LPV representation of the system is generatedfrom linearization of its usual Lagrangian equation about a desired state trajectory and is reduced to an uncertainpolytopic one. A vector of scheduling signals from the desired trajectory information is produced to construct theLPV model. The control gain matrix is derived by solving a set of linear matrix inequalities (LMIs) that returnsthe sufficiently small value of the time derivative of the Lyapunov function. A sufficient condition is proposedto guarantee the asymptotic stability of the closed-loop LPV systems against the uncertainties on the vertices. The proposed scheme is applied to controller synthesis of a two-degree-of-freedom robotic manipulator trajectorytracking problem.

The Effect of Vitis vinifera L. Juice on Serum Levels of Inhibin B, Sperm Count in Adult Male Rats

Mohammad Reza Afzalzadeh,Akram Ahangarpour,Ashraf Amirzargar,Mohammad Kazemi Varnamkhasti,Hadi Ganjalidarani 대한남성과학회 2015 The World Journal of Men's Health Vol.33 No.2

Purpose: Vitis vinifera is a species of Vitis that is native to the Mediterranean region, central Europe, and southwestern Asia, and has been used as a drug in traditional medicine. Traditional medicinal plants have been used for medical purposes with increasing effectiveness. It is important to identify drugs that inhibit spermatogenesis. Therefore, the present study aimed to investigate the effect of grape juice (GJ) on serum levels of inhibin B and sperm count in normal male rats.Materials and Methods: Thirty-five adult male rats were randomly divided into five groups, each containing seven rats. Rats in the control group received 1 mL of normal saline over the course of the study. The experimental groups received GJ (100, 200, 400, and 1,600 mg/kg, orally, for 35 days consecutively). At the end of the treatment period, fertility indices were measured, including body weight difference, sex organ weight, sperm motility and count, epididymal sperm reserve, daily sperm production (DSP), and serum inhibin B levels.Results: We found that GJ reduces body weight difference, was associated with decreased sperm motility and count in all treatment groups (p≤0.05 and p≤0.001, respectively). Moreover, DSP was significantly decreased in all treatment groups compared to the control group (p≤0.05), except in the group receiving 100 mg/kg of GJ. Inhibin B levels were significantly decreased in all treatment groups (p≤0.05).Conclusions: The results of our study suggest that GJ in all doses, but especially in higher doses, may decrease fertility in male rats.

Modeling of Inelastic Mixed Hinge and its Application in Analysis of the Frames with Reduced Beam Section

Mohammad Taghi Kazemi,Masoud Hoseinzadeh Asl 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.1

This paper represents new development of a previously introduced mixed shear-flexural (VM) link element, and its application in inelastic analysis of frames with reduced beam sections. The multi-surfaces concept with dissimilar yield surfaces is used in definition of link element. The yield surfaces are defined in deformation space and the element has the capability of modeling interactive axial-flexural-shear yielding. It is able to consider post yield softening behavior as well as flexibility and strength degradations. It is shown that the analysis results of the new mixed axial-shear-flexural (PVM) link have good agreement with the existing experimental and finite element results. Using the PVM link element, nonlinear dynamic analyses are performed on a benchmark intermediate moment frame and its improved versions with reduced beam section (RBS) and reduced web beam section (RWS). The results show that the use of RWS connections, can considerably improve the seismic performance of the steel frames, at least, as much as RBS.

Structural instability of carbon nanotubes embedded in viscoelastic medium and subjected to distributed tangential load

Mohammad Ali Kazemi-Lari,Esmaeal Ghavanloo,S. Ahmad Fazelzadeh 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.7

In this paper, the nonlocal Euler-Bernoulli beam model is used to predict the static and dynamic structural instability of carbon nanotubes (CNTs) subjected to a distributed tangential compressive load. The CNT is considered to be embedded in a Kelvin-Voigt viscoelastic medium. Equation of motion and boundary conditions are obtained using the extended Hamilton’s principle and the extended Galerkin’s method is applied in order to transform the resulting equations into a general eigenvalue problem. The derived equations are validated by comparing the results achieved from the new derivations with existing solutions in literature. Effects of several experimentally interesting boundary conditions are considered on the stability characteristics of the CNT. Moreover, the influences of small scale parameter and material properties of the surrounding viscoelastic medium on the stability boundaries are examined.

Income-related inequality in completed suicide across the provinces of Iran

Mohammad Hassan Kazemi-Galougahi,Asieh Mansouri,Samaneh Akbarpour,Mahmood Bakhtiyari,Majid Sartipi,Rahmatollah Moradzadeh 한국역학회 2018 Epidemiology and Health Vol.40 No.-

OBJECTIVES: The aim of this study was to measure income-related inequality in completed suicide across the provinces of Iran. METHODS: This ecological study was performed using data from the Urban and Rural Household Income and Expenditure Survey-2010 conducted by the Iranian Center of Statistics, along with data on completed suicide from the Iranian Legal Medicine Organization in 2012. We calculated the Gini coefficient of per capita income and the completed suicide rate, as well as the concentration index for per capita income inequality in completed suicide, across the provinces of Iran. RESULTS: The Gini coefficients of per capita income and the completed suicide rate in the provinces of Iran were 0.10 (95% confidence interval [CI], 0.06 to 0.13) and 0.34 (95% CI, 0.21 to 0.46), respectively. We found a trivial decreasing trend in the completed suicide incidence rate according to income quintile. The poorest-to-richest ratio in the completed suicide rate was 2.01 (95% CI, 1.26 to 3.22). The concentration index of completed suicide in the provinces of Iran was -0.12 (95% CI, -0.30 to 0.06). CONCLUSIONS: This study found that lower income might be considered as a risk factor for completed suicide. Nonetheless, further individual studies incorporating multivariable analysis and repeated cross-sectional data would allow a more fine-grained analysis of this phenomenon.

CURVATURES OF SEMI-SYMMETRIC METRIC CONNECTIONS ON STATISTICAL MANIFOLDS

Balgeshir, Mohammad Bagher Kazemi,Salahvarzi, Shiva Korean Mathematical Society 2021 대한수학회논문집 Vol.36 No.1

By using a statistical connection, we define a semi-symmetric metric connection on statistical manifolds and study the geometry of these manifolds and their submanifolds. We show the symmetry properties of the curvature tensor with respect to the semi-symmetric metric connections. Also, we prove the induced connection on a submanifold with respect to a semi-symmetric metric connection is a semi-symmetric metric connection and the second fundamental form coincides with the second fundamental form of the Levi-Civita connection. Furthermore, we obtain the Gauss, Codazzi and Ricci equations with respect to the new connection. Finally, we construct non-trivial examples of statistical manifolds admitting a semi-symmetric metric connection.

Evaluation the behavior of pre-fabricated moment connection with a new geometry of pyramidal end block under monotonic and cyclic loadings

Seyed Morteza Kazemi,Mohammad Reza Sohrabi,Hasan Haji-Kazemi 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.3

Researchers have been long studying new building implementation methods to improve the quality of construction, reduce the time of assembly, and increase productivity. One of these methods is the use of modular pre-fabricated structural forms that are composed of a beam, column, short column, pyramidal end block, and connection plates. In this study, a new geometry for the pyramidal end block was proposed that helps facilitate the assembly procedure. Since the proposed configuration affects the performance of this form of connection, its behavior was evaluated using finite element method. For this purpose, the connection was modeled in ABAQUS and then validated by comparing the outputs with experimental results. The research proceeded through analyzing 16 specimens under monotonic and cyclic loading. The results indicated that using the pyramidal end block not only makes the assembly process easier but also reduces the out-of-plane displacement of the short column webs and the vertical displacement of beam end. By choosing appropriate section properties for column and beam, the connection can bear a rotation up to 0.01 radians within its inelastic region and a total of 0.04 radians without any significant reduction in its bearing capacity.

Design equations for prefabricated steel moment connections

Seyed Morteza Kazemi,Mohammad Reza Sohrabi,Hasan Haji Kazemi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.3

Recently, modular prefabricated steel moment connections have been widely studied by several researchers. These connections are made of tubular columns that are ended to horizontal plates at both sides, an inter-story short column, and truss beams that are joined to the connecting plates using top and bottom plates. In this study, a series of equations have been developed and presented for designing each component of this type of connection. Then, to verify the proposed equations, the connection was modeled in ABAQUS and then the results extracted from the equations and modeling were compared. The findings indicated that the proposed equations have the required accuracy.

The effect of beam section property on the behavior of modular prefabricated steel moment connection

Seyed Morteza Kazemi,Mohammad Reza Sohrabi,Hasan Haji Kazemi 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.6

The specially prefabricated steel moment connections with pyramid head is one of the significant innovations in the steel structures forms to improve the installation time and simplify the construction procedure. The beams in this structure form are supported by two top and bottom angles and web double angles. Such a configuration despite its advantages increases the welding operation and filed installation time and costs. In this paper, the effect of using beams with channel and I section in three classes of seismically compact, seismically non-compact, and slender section according to width-to-thickness ratio on the behavior of the connection was investigated under monotonic and cyclic loading. Modeling was performed by ABAQUS and verified by the results of an experimental specimen. The findings indicated that using I and channel section instead of angle section reduces the amount of welding materials as well as easing the installation procedure. However, it has no significant effect on the ultimate strength and ductility of the connection. Furthermore, if the beam section is seismically compact, this form is considered as a special moment frame that has a rotation capacity up to 0.04 radians without any reduction in connection moment resistance.

Charge reduction: an efficient strategy to reduce toxicity and increase the transfection efficiency of high molecular weight polyethylenimine

Mohammad Ramezani,Reza Kazemi Oskuee,Mehdi Rezaee,Leila Gholami,Mojtaba Seddighi Gildeh 한국약제학회 2019 Journal of Pharmaceutical Investigation Vol.49 No.1

With high potency in treatment of various diseases, gene therapy is mainly hindered by lack of safe and efficient gene delivery vectors. The current study was aimed to develop an efficient non-viral vector with adequate cytotoxicity. To this end, alkylcarboxylate chains (6C, 10C, 16C) were exploited to ameliorate the characteristics of PEI 750 kDa. Briefly, alkylcarboxylate chains with three different lengths (6C, 10C, 16C) were chemically grafted to the primary amine groups of PEI 750 kDa in three percentages (10, 50, and 100%). After evaluating the physicochemical properties of prepared vectors including surface charge, size, buffering capacity, and DNA condensing, their transfection efficiency and cytotoxicity were investigated in Neuro2A cells. The polyplexes size were 158.9–264.5 nm and their zeta potentials were 14–30 mV, while their buffering capacity and DNA condensing were not significantly decreased. The highest transfection efficiency in term of C/P ratio was observed in PEI750-10C-68%, PEI750-10C-7%, and PEI750-6C-7% at C/P ratios of 2, 4, and 6, respectively. Altogether, the decanoylcarboxylate-modified PEI with medium grafting percentages showed promising results as gene delivery vector. To sum up, the modification of high molecular weight PEIs by alkylcarboxylate chains is an efficient approach for development of more efficient non-viral vectors.