Zwięzły kurs analizy numerycznej

"...Materiał przedstawiony w tej książce to wybrane przez autorów metody numeryczne prezentowane studentom różnych kierunków studiów inżynierskich w trakcie wykładów, ćwiczeń i laboratoriów. Mamy nadzieję, że przygotowane w zwartej postaci podstawowe informacje z analizy numerycznej ułatwią studentom usystematyzowanie i przyswojenie wiedzy. Uczestnictwo w wykładzie,ćwiczeniach i laboratoriach umiejscowi tę wiedzę w kontekście zastosowań oraz pozwoli na rozwinięcie praktycznych umiejętności...

New tetrahydroacridine hybrids with dichlorobenzoic acid moiety demonstrating multifunctional potential for the treatment of Alzheimers disease

A series of new tetrahydroacridine and 3,5-dichlorobenzoic acid hybrids with different spacers were designed, synthesized, and evaluated for their ability to inhibit both cholinesterase enzymes. Compounds 3a, 3b, 3f, and 3g exhibited selective butyrylcholinesterase (EqBuChE) inhibition with IC50 values ranging from 24 to 607 nM. Among them, compound 3b was the most active (IC50 = 24 nM). Additionally, 3c (IC50 for EeAChE = 25 nM and IC50 for EqBuChE = 123 nM) displayed dual cholinesterase inhibitory activity and was the most active compound against acetylcholinesterase (AChE). Active compound 3c was also tested for the ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated using ACD Labs Percepta and Chemaxon. A Lineweaver-Burk plot and docking study showed that 3c targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, 3c appears to possess neuroprotective activity and could be considered a free-radical scavenger. In addition, 3c did not cause DNA damage and was found to be less toxic than tacrine after oral administration; it also demonstrated little inhibitory activity towards hyaluronidase (HYAL), which may indicate that it possesses anti-inflammatory properties. The screening for new in vivo interactions between 3c and known receptors was realized by yeast three-hybrid technology (Y3H)

Fuzzy systems in permanent magnet motors description

Several artificial intelligence techniques for fuzzy modelling of flux distribution, electromagnetic and disturbance (friction, ripples) torques in permanent magnet rotational motors are proposed. Based on a model taking into account several nonlinear phenomena such as non-sinusoidal flux linkage, saturation effects etc observer-based parameter identifiers approach is used to plan identification experiments and to obtain the data. Next fuzzy models are applied to approximate the experimental data. Several training algorithms tuning the fuzzy model parameters and to simplifying the model structure are compared

Integrated, Multi-Approach, Adaptive Control of Two-Mass Drive with Nonlinear Damping and Stiffness

In numerous electric drive applications, the mechanical phenomena in the velocity or position control loop determine real difficulties and challenges for the control system. So-called two-mass drive systems with a flexible shaft are the most important example of this situation. The problem becomes even more difficult if the characteristics of torque transmission along the shaft are nonlinear, nonlinear friction is present, and the plant parameters are unknown, as it happens in numerous robotic systems. A novel adaptive controller is derived for such a system. The recurrent design procedure is based on proper modifications of the adaptive backstepping scheme, including non-strict-feedback plant application, tuning functions to exclude controller overparameterization, robust adaptive laws, proper means to avoid controller complexity explosion, and a nonlinear PI controller in the initial loop to minimize quasi-steady-state tracking error. The closed-loop system uniform ultimate boundedness is proven using Lyapunov techniques and the design and tuning procedures are described. The attractive features of the obtained drive, including the robustness against the violation of assumptions, are presented using several examples

Is Extreme Learning Machine Effective for Multisource Friction Modeling?

Part 5: Machine LearningInternational audienceThe aim of this contribution is to discuss suitability of extreme learning machine (ELM) approach for modeling multisource friction for motion control purposes. The specific features of multisource friction in mechatronic systems are defined, the main aspects of friction modeling by a standard ELM are investigated and some modifications are proposed to make it more suitable for specific demands of the discussed task. This allows to formulate some general remarks concerning properties of ELM for function approximation

Synchronization of an Uncertain Duffing Oscillator with Higher Order Chaotic Systems

The problem of practical synchronization of an uncertain Duffing oscillator with a higher order chaotic system is considered. Adaptive control techniques are used to obtain chaos synchronization in the presence of unknown parameters and bounded, unstructured, external disturbances. The features of the proposed controllers are compared by solving Duffing-Arneodo and Duffing-Chua synchronization problems

Application of adaptive and fuzzy techniques in control of permanent magnet motors

The scope of the paper is to demonstrate that fuzzy models together with adaptive control techniques are useful methods in control permanent magnet motor's currents, speed and position. It is dso pointed out that fuzzy flux distribution models can be helpful to obtain so called "circle diagram" of the machine with saturation and to derive optimal desired currents trajectories. The applicability of disturbance fuzzy model for solving the problem of tracking position control oflinear motor is also demonstrated