Controlled Lagrangian method uses the inherent geometric structure of the energy of the mechanical systems to provide a stabilizing algorithm for underactuated mechanical systems. The presented method belongs to a larger family of nonlinear control algorithms, namely energy shaping methods in which the controller is designed by providing necessary modifications in the mechanical energy of the system. This paper presents a sensitivity analysis of Controlled Lagrangian method. It is shown that the method presents a suitable performance under the effect of structured (or parametric) uncertainties such as masses values, their positions and their influence on the inertia tensor. Then, the sequel investigates the robustness level of the designed controller in the presence of structured uncertainties. A detailed robustness proof of the scheme is established in this paper. Simulations are provided for a linear inverted pendulum cart system to validate analytical results of robustness to parametric uncertainties. Simulation results confirm that the designed controller for the inverted pendulum, which is unstable and underactuated, is well robust against parametric uncertainties as the analytical studies predicted. The method was also compared with the sliding mode approach, which showed a superior robustness against parametric uncertainties and a more practical control input value.

Background and Objectives: In genetic network control, RC-Centrality is introduced as a new control centrality measure to address the control of linear time-invariant networks. The objective of this study is to propose an optimal control centrality metric that quantifies the centrality of individual nodes or groups of nodes within a network. Specifically, RC-Centrality identifies key nodes or node groups that can act as controllers, such as genes regulating the gene expression process. To assess the effectiveness of this method, RC-Centrality is compared with standard centralities in a real genetic network. Additionally, the research delves into the role of uncertainty structure in altering the priority order of RC-Centrality.Methods: The RC-Centrality measure is introduced based on an optimal control problem to address weighted, directed, and signed networks. Robust controllers are designed to ensure Lyapunov stability under uncertainty. A cost function is introduced to measure the performance metric represented by input energy in the presence of uncertainty.Results: The study presents RC-Centrality as an effective measure for identifying key nodes in genetic networks suitable for control. In-silico simulations are conducted to evaluate its performance in comparison to standard centralities. The research highlights the impact of uncertainty structure on the priority of RC-Centrality.Conclusion: RC-Centrality offers a promising approach to identify essential nodes in genetic networks for control purposes. Its performance is demonstrated through simulations, and the study emphasizes the influence of uncertainty structure on the centrality measure's prioritization. This research has implications for understanding and controlling genetic networks, particularly in the presence of uncertainty.

One of the areas of language, now seen as part of language competence in the light of new theories of language proficiency, is textual competence with two subcomponents: coherence and rhetorical organization. The present study is an attempt to measure Iranian EFL learners' knowledge of rhetorical organization through structured and unstructured summary writing, and seeks to find out whether text type and test format affect learners' performance on summary writing tests. The validity and reliability of the two test formats are also compared with each other.The results obtained confirm the effect of text type and test format on learners' performance on a summary writing test verifying Kobayashi (2000) and Bachman's (1990) assertions about the effect of text structure and test method on learners' test performance. A significant interaction between text type and test format is also found. Concerning the validity and reliability of the two test formats, higher concurrent validity and inter and intra rater reliability indices are registered for structured summary writing. However, both test formats show a low face validity index.

The water level control in boiler drums is a crucial process in many process industries. In industries, water spillage or overheated tubes of the water boiler are the serious consequences of extremely high or low-level drum water level maintenance. The boiler drum is a MIMO system, consists of dead time nonlinearity and thereby there exists a transportation lag between the input and the system. Also, they possess high dynamic variations. Hence, the control of the boiler drum level is of great importance. Though, conventional PID controllers are employed in industries, due to the presence of nonlinearity, boiler drum performance can be affected when it is controlled by a PID controller. Moreover, the PID controller produces a larger settling time. Here, a robust controller for the boiler drum level control based on the H-infinity technique is designed. The first-principle mathematical model of the boiler drum is formulated. The uncertainties namely: structured uncertainty, unstructured uncertainty, and nonlinear uncertainty are modeled by incorporating the boiler drum dynamics including its inherent nonlinearity. The boiler drum level control is carried out using the H-infinity controller scheme with the uncertainties accounted for and the performance is compared with that of a conventional PID controller. The qualitative and quantitative comparison of performances of the above control schemes reveals that the H-infinity controller has a quick rise time and faster settling time.

Induction motors with nonlinear dynamics are superior in terms of size, weight, motor inertia, maximum speed, efficiency, and cost than direct current machines, and hence their control is of great important. The main objective of this paper is to design a fuzzy sliding mode controller in order to control the position of the induction motor including parametric and non-parametric uncertainties by considering the stability issue. In fact, in this method, in order to increase the performance of the control system and to improve the tracking performance, a moving sliding surface is considered, in which it is adapted in accordance with the variations of the sliding surface. As a result, during the reaching phase, the system is not sensitive to parameter variations and external disturbances. Simulation results show that the proposed control method has good performance in the face of parametric and non-parametric uncertainties.

In most of the researches which has been conducted until now on the robot manipulator tracking control, it has been presumed which the kinematic of robot manipulator or Jacobian Matrix of robot from the joint space to the task space is quite known. However, none of the physical parameters in robot manipulator equations can be calculated by high accuracy. In addition, when the robot manipulator moves something, uncertainties occur in length, direction and point of contact of end-effector. Hence, uncertainties occur on the kinematic of robot manipulator either, and due to the different functions of the robot manipulator, its kinematic is changed as well. Therefore, ensuring stability of the closed-loop system in the presence of uncertainties in the dynamics and kinematics of robot manipulator is quite challenging. In this paper, for overcoming on these uncertainties, we present our simple robust control for tracking the position of robot manipulator in the presence of uncertainties in the dynamics kinematics and Jacobian Matrix of the robot manipulator. The proving of the stability shows the closed-loop system has Global asymptotic stability. Then, to overcome the practical problems of proposed control, amendments will be provided. The closed loop system with improved control has limited uniform stability. Since in many of the operations has been performed by the robot manipulator, transient error plays an important role. Due to this reason, the modified control structure is a changed in a way which could improve the transient error. Finally, for displaying the function of the final controller, a case study is implemented on a two-link elbow robot. Mathematical proof and simulation results confirm the good performance of the proposed control.

In this paper,we proposed solutions for controlling the two,wheel self,balancing robot system in the presence of uncertainties in dynamical equation and without the need for kinematic equations.For this purpose,the dynamical equations of this system are initially transmitted to the domain of error,then these equations are divided into two independent subsystems,one of which is an under,actuated system and the other is fully actuated system.In order to control the under,actuated subsystem,two completely different sliding mode controllers are proposed that are able to provide this subsystem in the presence of structured and un,structured uncertainties with global asymptotic stability.Subsequently,in order to control the fully under,actuated subsystem,a sliding mode control is proposed to provide this subsystem in the presence of existing uncertainties with global asymptotic stability.Since these two subsystems are completely independent of each other,their global asymptotic stability proofs prove the global asymptotic stability of the closed,loop system.The separation of two,wheeled self,balancing robot sub,systems eliminates the need to use the kinematic equations,and this causes the presence of structured uncertainties to have no effect on the accuracy of tracing the closed,loop system state variables.Finally,to evaluate the performance of the proposed controllers and compare their performance results,three,stage simulations are implemented on the two,wheeled self,balancing robot system.Mathematical proofs and simulation results show the desired performance of the proposed solutions.

Introduction: Play is one of the methods for teaching the necessary movement, emotional and social skills, and structured play is the basis for children's normal communication and learning processes. Aim: The purpose of this study was the effectiveness of a selected movement program of structured, unstructured, and mixed on the social and psychological development of children aged 4-6 years. Method: The present research method was semi-experimental with a pretest-posttest design. The statistical population included children aged 4-6 years in district-5 of Tehran in 2020. The statistical sample included 60 children who were randomly selected and divided into three groups of 20 children. The studied groups trained for 12-weeks according to their implementation protocol, two session’s per-week and one-hour per-session. The research groups completed Vineland Social Development Questionnaire (1989) and Children Psychological Development (2010) before and after the intervention. A mixed ANOVA and Bonferroni post-hoc tests were used to analyze the data. All statistical analyzes were performed using SPSS version-26 software. Results: The results showed that for social and psychological development, the main effect of levels and the interactive effect of group levels were significant (P<0. 05), but the main effect of group was not significant (P>0. 05). The results of the Bonferroni post hoc test showed that there was a significant difference between the mixed and structured groups (P<0. 05), but no significant difference between the unstructured and structured groups and between the mixed and unstructured groups (P>0. 05). Conclusion: Based on the results indicating the effectiveness of the mixed exercises on psychological and social development, it is suggested that professionals and physical education teachers use these protocols to improve and promote these skills.