The Sliding Mode Control (SMC) has been among powerful control techniques increasingly. Much attention is paid to both theoretical and practical aspects of disciplines due to their distinctive characteristics such as insensitivity to bounded matched uncertainties, reduction of the order of sliding equations of motion, decoupling mechanical systems design. In the current study, two-link robot performance in the Classical SMC is enhanced via Adaptive Sliding Mode Controller (ASMC) despite uncertainty, external disturbance, and coulomb friction. The key idea is abstracted as follows: switching gains are depressed to the low allowable values, resulting in decreased chattering motion and control's efforts of the two-link robo
... Show MoreA new Differential Evolution (ARDE) algorithm is introduced that automatically adapt a repository of DE strategies and parameters adaptation schemes of the mutation factor and the crossover rate to avoid the problems of stagnation and make DE responds to a wide range of function characteristics at different stages of the evolution. ARDE algorithm makes use of JADE strategy and the MDE_pBX parameters adaptive schemes as frameworks. Then a new adaptive procedure called adaptive repository (AR) has been developed to select the appropriate combinations of the JADE strategies and the parameter control schemes of the MDE_pBX to generate the next population based on their fitness values. Experimental results have been presented to confirm the reli
... Show MoreThe regressor-based adaptive control is useful for controlling robotic systems with uncertain parameters but with known structure of robot dynamics. Unmodeled dynamics could lead to instability problems unless modification of control law is used. In addition, exact calculation of regressor for robots with more than 6 degrees of freedom is hard to be calculated, and the task could be more complex for robots. Whereas the adaptive approximation control is a powerful tool for controlling robotic systems with unmodeled dynamics. The local (partitioned) approximation-based adaptive control includes representation of the uncertain matrices and vectors in the robot model as finite combinations of basis functions. Update laws for the weighting matri
... Show MoreBackground: Laparoscopic cholecystectomy (LC) has become the standard treatment for symptomatic cholelithiasis. Bile duct injury and accidental gallbladder perforation with spillage of bile and stone are common complications of LC. This study was carried out to assess the early complications of gallbladder perforation during LC, and identify the risk factor of that perforation.
Objectives: to evaluate the early complications which may occur after the perforation of the gallbladder during laparoscopic cholecystectomy and to determine the risk factors which are associated with the perforation of the gall bladder.
Subjects and methods: A prospective comparative study o
... Show MoreCrop production is reduced by insufficient and/or excess soil water, which can significantly decrease plant growth and development. Therefore, conservation management practices such as cover crops (CCs) are used to optimize soil water dynamics, since CCs can conserve soil water. The objective of this study was to determine the effects of CCs on soil water dynamics on a corn (
Urban wetlands are one of the complex systems that provide many economic, social and environmental services to the city. In this research, the most important services provided by urban wetlands from the point of view of the urban planner were reviewed, and the types of these lands and their divisions according to the type of services provided by each type were presented. Environmental is represented in its ability to reduce the dangers of floods, mitigate the climate and reduce its negative impacts, purify water and deplete a lot of suspended impurities and pollutants, and social services such as recreational areas and beautiful landscapes that inspire joy and reassurance in the soul, as well as cultural areas and sports activities for m
... Show MoreMany urban and rural areas fall under the impact of disasters, whether natural or industrial, and with increasing complexity in urban areas, with diversity of economic, social and political components, and technological and cognitive development, the effects of disasters and wars have increased with the time, where disasters are affecting all aspects of life, causing great waste of property and lives, also displacement of populations and disruption of economic life, these effects are multiplied if they are not dealt with in sound curricula and scientific strategies.
The research aims to identify the experiences of some countries and their strategies and effective programs in reconstruction after exposure to disasters and wars wit
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