Tracking guidance commands for a time-varying aerospace launch vehicle during the atmospheric flight is considered in this paper. Hence, the dynamic terminal sliding mode control law is constructed for this purpose and dynamic sliding mode control is utilized.The terminal sliding manifold causes the dynamic sliding mode to converge asymptotically to zero in finite-time. The actuator and rate gyro dynamics are included in the model of launch vehicle. Dynamic sliding mode control accommodates UNMATCHED DISTURBANCEs, while the terminal sliding mode control is used to accelerate the system to reach the dynamic sliding manifold. Finally, the effectiveness of the proposed control is demonstrated in the presence of UNMATCHED DISTURBANCEs and is compared with the dynamic sliding mode.

An algebraic method based on unknown input observer for fault estimation in linear time invariant system with unknown input is implementable if matching condition is satisfied. Matching condition limits practical application of these methods. In this article, a method is proposed for fault estimation which need not satisfy matching condition. Unlike classical methods, the provided method does not require auxiliary output for fault estimation. In the first step, the unknown input is divided in two parts: the matched and the UNMATCHED unknown inputs. Assuming that there exist a dynamic model for the UNMATCHED part, new augmented system is constructed. The augmented system is revealed as a new system with matched unknown input. Then, the effect of matched unknown input is perfectly removed from observer estimation using the traditional unknown input decoupling strategy. In the next step, the full order observer is designed for the augmented system. A fast adaptive law is employed for the fault estimation. Lyapunov stability condition of state and fault estimation are derived by linear matrix inequality (LMI) criteria. The effectiveness of the proposed method is shown via numerical simulation on a flexible joint example.

The present study seeks to explore the induction challenges of beginning teachers in the school environment. As a qualitative study, this phenomenological research used semistructured interviews for data collection. The key data for the study were collected from 22 beginning teachers graduated from Teacher Training University with one and two years of service. From the perspective of this group, the induction challenges of beginning teachers in the first primary schools were classified in three categories including: Individual challenges, professional challenges, and organizational challenges. The sources that could cause individual challenges are early-service tensions and anxieties, lack of support and isolation, and adaption with colleagues. Professional challenges could be caused by classroom management, content management and effective teaching, students’ assessment, addressing the students’ needs, trust and communicating with parents. And organizational challenges could arise from familiarity with the school, familiarity with the school practices, resources and population of students.

Background and Objectives: In some emergencies, blood transfusion is required while there is no time for crossmatching, antibody screening, and ABO/Rh typing. O negative blood can be used when there is not sufficient time for crossmatch. Case: A 68-year-old woman was transferred to the hospital cause of trauma. Due to her hemorrhage and paleness, intravenous isotonic fluids followed by 1 unit of O negative, 2 units of B positive, and 2 units of AB positive packed RBCs were administered. Her blood group was determined to be AB positive. She had neither any hemolytic symptoms nor any other problems and was discharged from the hospital. Conclusions: In emergencies when there is not enough time for crossmatching and antibody screening, O negative blood can be administered.

In this paper, a robust control law is proposed, based on Lyapunov’s theory and sliding mode control theory, in order to track the angle of attack in nonlinear longitudinal dynamics of a missile. It is assumed that there are UNMATCHED uncertainties in the nonlinear systems. In the proposed algorithm, the controller gains are optimized by Particle Swarm Optimization (PSO) algorithm. For this purpose, a cost function is extracted from the output tracking error. Simulation results show that the proposed algorithm has better performance than conventional Proportional-Integral-Derivative (PID) controller in the presence of UNMATCHED uncertainties.

Wing rock phenomenon is undesired vibration in rolling angle occurring in delta wing aircraft at large angles of attack. This paper presents three versions of model refernce adaptive controllers; namely classical MRAC, s-modified MRAC and weighted s-modified MRAC to control the rolling dynamics under wing rock phenomenon with the presence of UNMATCHED DISTURBANCE. The stability analysis of new proposed strategy for weighted s-modified MRAC has been presented. The effectiveness of the controllers is assessed in terms of their robusness under UNMATCHED DISTURBANCE. The simulated results based on MATLAB/SIMULINK show that s-modified adaptive controller gives better robustness characteristics than classical one; as it could confine different aircraft responses within smaller bounded limits. Moreover, as compared to s-modified controller, weighted s-modified controller gives better enhancement in terms of robustness, control effort and error charcteristics.