Recently, Shestakov-Umirbaev solved Nagata’s conjecture on an automorphism of a polynomial ring. To solve the conjecture, they defined notions called reductions of types I–IV for automorphisms of a polynomial ring. An automorphism admitting a reduction of type I was first found by Shestakov-Umirbaev. Using a computer, van den Essen–Makar-Limanov–Willems gave a family of such automorphisms. In t...

Recently, Shestakov-Umirbaev solved Nagata’s conjecture on an automorphism of a polynomial ring. To solve the conjecture, they defined notions called reductions of types I–IV for automorphisms of a polynomial ring. An automorphism admitting a reduction of type I was first found by Shestakov-Umirbaev. Using a computer, van den Essen–Makar-Limanov–Willems gave a family of such automorphisms. In t...

This contribution deals with the synthesis of discrete supervisory control for switched linear systems. Via two successive approximation steps, this hybrid control problem is transformed into a purely discrete problem. The latter can then be solved using a slightly modified version of P. J. Ramadge’s and W. M. Wonham’s “supervisory control theory”. By embedding both approximation steps within J...

This contribution treats the estimation of reachable states for time invariant hybrid systems. Using the framework provided by Willems’ behavioural systems theory, we suggest a method based on -complete approximations, which can be realized by finite state machines. The approximating behaviour is a superset of the original behaviour. Hence, the estimate of reachable states based on an -complete...

در این تحقیق به مقایسه تحلیلی و عددی آبشار جریان برگشتی مدل R با آبشارهای Q QI سیستم‌­های چندجزیی پایدار پرداخته می‌­شود. راستا برای اولین بار کدهای جهت طراحی منظور کد نرم‌افزار متلب نوشته شده‌­اند. نتایج نشان می‌­دهد که دو جزء 1k 2k از خوراک Nc جزء، تعداد معدودی قابل تعریف است همگی حالات خاصی می­‌باشد. هم‌­چنین یافته‌­ها مجموع مقدار برش جزیی همیشه برابر یک است. طریق داده می‌­شود صورتی میانگین ...

هدف: این پژوهش با هدف ارائه مدل چالش‌های پرورش کودکان کم‌شنوای پیش‌دبستانی از دیدگاه مادران و متخصصان بر اساس نظریه داده‌بنیاد انجام ‌شده است. روش: نمونه 15 مادر کودک کم‌شنوا 4 تا 6 ساله انجمن والدین شهر تهران 5 متخصص حوزه ناشنوا بودند که در سال 1400 استفاده روش نمونه‌گیری هدفمند انتخاب شدند. چالش ­های طریق مصاحبه نیمه ساختاریافته عمیق رسیدن به اشباع نظری جمع‌آوری کدگذاری (کدگذاری باز، محوری ان...

We present an extension of Willems' Fundamental Lemma to the class multi-input multi-output discrete-time feedback linearizable nonlinear systems, thus providing a data-based representation their input-output trajectories. Two sources uncertainty are considered. First, unknown linearizing input is inexactly approximated by set basis functions. Second, measured output data contaminated additive ...

This contribution deals with the synthesis of supervisory control for hybrid systems with discrete external signals. Such systems are in general neither l-complete nor representable by nite state machines. We nd the strongest l-complete approximation (abstraction) l for , represent it by a nite state machine , and investigate the control problem for the approximation. If a solution exists, we s...