Positive Systems

The proceedings of the First Multidisciplinary International Symposium on Positive Systems Theory and Applications (POSTA 2003) held in Rome, Italy, August 28-30, 2003. Positive Systems are systems in which the relevant variables assume nonnegative values. These systems are quite common in applications where variables represent positive quantities such as populations, goods, money, time, data packets flowing in a network, densities of chemical species, probabilities, etc. The aim of the symposium was to join together researchers working in the different areas related to positive systems such as telecommunications, economy, biomedicine, chemistry and physics in order to provide a multidisciplinary forum where they have the opportunity to exchange ideas and compare results in a unifying framework.

This volume contains the proceedings of the "Third Multidisciplinary Symposium on Positive Systems: Theory and Applications (POSTA09)" held in Valencia, Spain, September 2–4, 2009. This is the only world congress whose main topic is focused on this field.

This book presents high-quality original contributions on positive systems, including those with positivity in compartmental switched systems, Markovian jump systems, Boolean networks, interval observer design, fault detection, and delay systems. It comprises a selection of the best papers from POSTA 2018, the 6th International Conference on Positive Systems, which was held in Hangzhou, China, in August 2018. The POSTA conference series represents a targeted response to the growing need for research that reports on and critically discusses a wide range of topics concerning the theory and applications of positive systems. The book offers valuable insights for researchers in applied mathematics, control theory and their applications.

This book presents high-quality original contributions on positive systems, including topics such as: monotone dynamical systems in mathematical biology and game theory; mathematical developments for networked systems in biology, chemistry and the social sciences; linear and nonlinear positive operators; dynamical analysis, observation and control of positive distributed parameter systems; stochastic realization theory; biological systems with positive variables and positive controls; iterated function systems; nonnegative dynamic processes; and dimensioning problems for collaborative systems. The book comprises a selection of the best papers presented at the POSTA 2016, the 5th International Symposium on Positive Systems, which was held in Rome, Italy, in September 2016. This conference series represents a targeted response to the growing need for research that reports on and critically discusses a wide range of topics concerning the theory and applications of positive systems.

This thesis introduces novel and significant results regarding the analysis and synthesis of positive systems, especially under l1 and L1 performance. It describes stability analysis, controller synthesis, and bounding positivity-preserving observer and filtering design for a variety of both discrete and continuous positive systems. It subsequently derives computationally efficient solutions based on linear programming in terms of matrix inequalities, as well as a number of analytical solutions obtained for special cases. The thesis applies a range of novel approaches and fundamental techniques to the further study of positive systems, thus contributing significantly to the theory of positive systems, a “hot topic” in the field of control.

The need for services that respond to the ‘maltreatment’ of children and to the struggles of families is at the core of social service systems in all developed nations. While these child and family welfare systems confront similar problems and incorporate common elements, there are substantial differences in philosophy, organization, and operation across international settings and models. In this new collection of essays, Nancy Freymond and Gary Cameron have brought together some of the finest international minds to provide an original and integrated discussion of child protection, family service, and community caring models of child and family welfare. The volume not only examines child protection and family service approaches within Western nations – including Canada, the United States, England, the Netherlands, France, and Sweden – it is also the first comparative study to give equal attention to Aboriginal community caring models in Canada and New Zealand. The comparisons made by the essays in this volume allow for a consideration of constructive and feasible innovations in child and family welfare and contribute to an enriched debate around each system. This book will be of great benefit to the field for many years to come.

Based on findings from a decade's worth of research, Creating Positive Systems of Child and Family Welfare provides original reflections on the everyday realities of families and front-line service providers involved with the system.

Faced with rapidly changing social and economic conditions, service professionals, policy developers, and researchers have raised significant concerns about the Canadian child welfare system. This book draws inspiration from experiences with three broad, international child welfare paradigms—child protection, family service, and community healing/caring (First Nations)—to look at how specific practices in other countries, as well as alternative experiments in Canada, might foster positive innovations in the Canadian child welfare approach. Foundational values and purposes, systems design and policy, and organization and management are discussed, as are front-line service delivery, service provider work environments, and the realities of daily living for families. Informed by recent research, the contributors provide clear directions for policy, administration, and service-delivery reforms. Informing policy debates addressing child maltreatment and family welfare, this book will serve as a vital resource for managers, service providers, professionals, and students in the fields of social work, child and youth care, family studies, psychology, and special education.