Qi Lu – författare

This book in two volumes, and with a foreword by the renowned Professor M.A.J. Williams, draws on evidence from coastal and inland regions, including desert dunes, wind-blown dust, river and lake sediments, glacial moraines, plant and animal fossils, isotope geochemistry, soils and prehistoric archaeology to better understand the genesis and development of dunes systems in selected northern hemisphere sand dunes from Asia, Africa and the Middle East regions.The collection of research papers and case studies that are presented in this book provide the reader with a wealth of information about the distribution and types of sand dunes and an insight into the complexity of sand dune formation, migration and management. Research in many countries across the northern hemisphere shows that dunes, whether coastal or inland, are under pressure around the world. Much of the pressure comes from human activities, and the anthropogenic disturbance, when coupled with global warming and alterations to the amount, frequency and temporal distribution of precipitation could lead to more serious management challenges in the future.There is much that we still need to find out about the origin, genesis and development of sand dunes so that they can be managed better. The difficult and complex questions being repeatedly raised can be answered only by interdisciplinary endeavours. Geomorphologists, geologists, palaeontologists, climatologists, ecologists, and others, can work together on research projects that better define the origin, evolution and development of dunes, both inland and along the coasts. Many chapters in this book attempt to reconstruct past climatic changes in deserts and their margins at a variety of scales in space and time in the expectation that such information might assist in preparing us for future global warming and drying.

This book in two volumes, and with a foreword by the renowned Professor M.A.J. Williams, draws on evidence from coastal and inland regions, including desert dunes, wind-blown dust, river and lake sediments, glacial moraines, plant and animal fossils, isotope geochemistry, soils and prehistoric archaeology to better understand the genesis and development of dunes systems in selected northern hemisphere sand dunes from Asia, Africa and the Middle East regions.The collection of research papers and case studies that are presented in this book provide the reader with a wealth of information about the distribution and types of sand dunes and an insight into the complexity of sand dune formation, migration and management. Research in many countries across the northern hemisphere shows that dunes, whether coastal or inland, are under pressure around the world. Much of the pressure comes from human activities, and the anthropogenic disturbance, when coupled with global warming and alterations to the amount, frequency and temporal distribution of precipitation could lead to more serious management challenges in the future.There is much that we still need to find out about the origin, genesis and development of sand dunes so that they can be managed better. The difficult and complex questions being repeatedly raised can be answered only by interdisciplinary endeavours. Geomorphologists, geologists, palaeontologists, climatologists, ecologists, and others, can work together on research projects that better define the origin, evolution and development of dunes, both inland and along the coasts. Many chapters in this book attempt to reconstruct past climatic changes in deserts and their margins at a variety of scales in space and time in the expectation that such information might assist in preparing us for future global warming and drying.

It is a longstanding unsolved problem to characterize the optimal feedbacks for general SLQs (i.e., stochastic linear quadratic control problems) with random coefficients in infinite dimensions; while the same problem but in finite dimensions was just addressed very recently. This paper is devoted to giving a solution to this problem under some assumptions which can be verified for interesting concrete models. More precisely, under these assumptions, we establish the equivalence between the existence of optimal feedback operator for infinite dimensional SLQs and the solvability of the corresponding operator-valued, backward stochastic Riccati equations. A key contribution of this work is to introduce a suitable notion of solutions (i.e., transposition solutions to the aforementioned Riccati equations), which plays a crucial role in both the statement and the proof of our main results.

The extreme climate variability that characterizes China's arid rangelands can cause drought and degradation, resulting in dust storms, floods, animal losses, financial hardship and a decline in food availability. Addressing the issues of even greater climate extremes in the future, this book discusses both new approaches and past successes and failures in order to provide the necessary insight to develop sustainable rangeland management strategies, drawing on regional case studies and lessons learned from Australia, Canada and the USA.

This book provides a brief, self-contained introduction to Carleman estimates for three typical second order partial differential equations, namely elliptic, parabolic, and hyperbolic equations, and their typical applications in control, unique continuation, and inverse problems.

This is the first book to systematically present control theory for stochastic distributed parameter systems, a comparatively new branch of mathematical control theory.

This is the first book to systematically present control theory for stochastic distributed parameter systems, a comparatively new branch of mathematical control theory.

The classical Pontryagin maximum principle (addressed to deterministic finite dimensional control systems) is one of the three milestones in modern control theory. The corresponding theory is by now well-developed in the deterministic infinite dimensional setting and for the stochastic differential equations. However, very little is known about the same problem but for controlled stochastic (infinite dimensional) evolution equations when the diffusion term contains the control variables and the control domains are allowed to be non-convex. Indeed, it is one of the longstanding unsolved problems in stochastic control theory to establish the Pontryagin type maximum principle for this kind of general control systems: this book aims to give a solution to this problem. This book will be useful for both beginners and experts who are interested in optimal control theory for stochastic evolution equations.