The study of the mapping class group Mod(S) is a classical topic that is experiencing a renaissance. It lies at the juncture of geometry, topology, and group theory. This book explains as many ...important theorems, examples, and techniques as possible, quickly and directly, while at the same time giving full details and keeping the text nearly self-contained. The book is suitable for graduate students.
This Open Access volume by the International Commission on Mathematical Instruction (ICMI) is an outcome of the ICMI Study 24 and gives a status-quo of school mathematics reform around the world and ...what we can learn from this movement. Each theme and section of the book offers descriptions and analyses of multiple case studies in different countries and contexts, along with opportunities to compare, contrast and learn from these diverse experiences. The volume provides a synthesis and meta-analysis of the different historical, geographical and global aspects of school mathematics reforms and explores in which way curricula are elaborated, proposed, changed, and reorganized. It offers a more informed and comprehensive analysis of the roles of different actors and of the many aspects influencing and shaping mathematics curriculum reforms that are taking or have taken place. It also explores the possibilities and means to tackle a curricular reform in the current scenario we live in and how to unfold future developments. This book will be of interest to practitioners and scholars with an interest in school mathematics curriculum reforms. It will also be a useful resource to those involved in school mathematics curriculum reform initiatives by providing current information about the curriculum changes that are taking place in respect of content, teacher education, educational materials, and a range of implementation challenges across diverse contexts.
"This new and expanded edition is intended to help candidates prepare for entrance examinations in mathematics and scientific subjects, including STEP (Sixth Term Examination Paper). STEP is an ...examination used by Cambridge Colleges for conditional offers in mathematics. They are also used by some other UK universities and many mathematics departments recommend that their applicants practice on the past papers even if they do not take the examination. Advanced Problems in Mathematics bridges the gap between school and university mathematics, and prepares students for an undergraduate mathematics course. The questions analysed in this book are all based on past STEP questions and each question is followed by a comment and a full solution. The comments direct the reader’s attention to key points and put the question in its true mathematical context. The solutions point students to the methodology required to address advanced mathematical problems critically and independently. This book is a must read for any student wishing to apply to scientific subjects at university level and for anyone interested in advanced mathematics. "This new and expanded edition is intended to help candidates prepare for entrance examinations in mathematics and scientific subjects, including STEP (Sixth Term Examination Paper). STEP is an examination used by Cambridge Colleges for conditional offers in mathematics. They are also used by some other UK universities and many mathematics departments recommend that their applicants practice on the past papers even if they do not take the examination. Advanced Problems in Mathematics bridges the gap between school and university mathematics, and prepares students for an undergraduate mathematics course. The questions analysed in this book are all based on past STEP questions and each question is followed by a comment and a full solution. The comments direct the reader’s attention to key points and put the question in its true mathematical context. The solutions point students to the methodology required to address advanced mathematical problems critically and independently. This book is a must read for any student wishing to apply to scientific subjects at university level and for anyone interested in advanced mathematics.
Linear continuous-time systems with switched pointwise delays are studied. A technique enabling to establish the stability of these systems with a rapidly varying periodic delay is proposed. It ...relies on two ingredients: a representation of the systems as time-varying systems with constant delays and an averaging approach. Illustrative examples show the effectiveness of the proposed methodology.
This work presents the KKL observer design for nonlinear time-varying discrete systems. We first give sufficient conditions on the existence of a sequence of functions (T_k) transforming the given ...system dynamics into an exponentially stable filter of the output in some other target coordinates, where an observer is directly designed. Then, we prove that under uniform Lipschitz backward distinguishability, the maps (T_k) become uniformly Lipschitz injective after a certain time if the target dynamics are pushed sufficiently fast. This leads to an arbitrarily fast discrete observer after a certain time, which exhibits similarities with the famous high-gain observer for continuous-time systems. Input-to-state stability of the estimation error with respect to uncertainties, input disturbances, and measurement noise is then shown. Next, under the milder backward distinguishability, we show the injectivity of the maps (T_k) after a certain time for a generic choice of the target filter dynamics. Examples including a discretized permanent magnet synchronous motor (PMSM) illustrate the proposed observer.
In this paper, we propose sufficient conditions to guarantee that a linear temporal logic formula of the form p Until q , denoted by pUq , is satisfied for a hybrid system. Roughly speaking, the ...formula pUq is satisfied means that the solutions, initially satisfying proposition p , keep satisfying this proposition until proposition q is satisfied. To certify such a formula, connections to invariance notions – specifically, conditional invariance and eventual conditional invariance – as well as finite-time convergence properties are established. As a result, sufficient conditions involving the data of the hybrid system and an appropriate choice of Lyapunov-like functions, such as barrier functions, are derived. Examples illustrate the results throughout the paper.
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