Abstract : "We introduce a new invariant semantics of concurrent systems which is a direct generalisation of the causal partial order semantics. Our new semantics overcomes some of the problems encountered when one uses causal partial orders alone. We discuss various aspects of the new invariant model. In particular, we outline how the new invariants can be generated by 1-safe inhibitor Petri nets."
We claim that the new three-level approach allows for a better classification of invariant properties of concurrent behaviours, and leads to a model in which issues such as priority systems and nets with inhibitor arcs may be properly dealt with."
Paradigms of Concurrency: Observations, Behaviours, and Systems - a Petri Net View - Ryszard Janicki (McMaster University, CA) Jetty Kleijn (Leiden University, NL) Maciej Koutny (Newcastle University, UK) Lukasz Mikulski (Nicolaus Copernicus University, PL) Concurrency can be studied at different yet consistent levels of abstraction: from individual behavioural observations via more abstract concurrent histories that can be represented by causality structures capturing invariant dependencies between executed actions, to system level constructs such as Petri nets or process algebra expressions. Histories can then be understood as sets of closely related observations. Depending on the nature of the observed relationships between executed actions involved in a single concurrent history, one may identify different concurrency paradigms underpinned by different kinds of causality structures such as partial orders. This book studies fundamental mathematical abstractions to capture and relate observations, histories, and systems. In particular, taking a Petri net view, we present system models fitting various concurrency paradigms and their associated causality structures.
The hierarchical decomposition of programs into smaller ones is generally considered imperative to master the complexity of large programs. The impact of this principle of program decomposition on the specification and verification of parallel executed programs is the subject of this monograph. Two important yardsticks for verification methods, those of compositionality and modularity, are made precise. The problem of reusing software is addressed by the introduction of the notion of specification adaptation. Within this context, different methods for specifying the observable behavior with respect to partial correctness of communicating processes are considered, and in particular the contrast between the "programs are predicates" and the "programs are predicate transformers" paradigms is shown. The associated formal proof systems are proven sound and complete in various senses with respect to the denotational semantics of the programming language, and they are related to each other to give an in-depth comparison between the different styles of program verification. The programming language TNP used here is near to actual languages like Occam. It combines CCS/CSP style communication based programming with state based programming, and allows dynamically expanding and shrinking networks of processes.
Paradigms of Concurrency: Observations, Behaviours, and Systems - a Petri Net View - Ryszard Janicki (McMaster University, CA) Jetty Kleijn (Leiden University, NL) Maciej Koutny (Newcastle University, UK) Lukasz Mikulski (Nicolaus Copernicus University, PL) Concurrency can be studied at different yet consistent levels of abstraction: from individual behavioural observations via more abstract concurrent histories that can be represented by causality structures capturing invariant dependencies between executed actions, to system level constructs such as Petri nets or process algebra expressions. Histories can then be understood as sets of closely related observations. Depending on the nature of the observed relationships between executed actions involved in a single concurrent history, one may identify different concurrency paradigms underpinned by different kinds of causality structures such as partial orders. This book studies fundamental mathematical abstractions to capture and relate observations, histories, and systems. In particular, taking a Petri net view, we present system models fitting various concurrency paradigms and their associated causality structures.
This book contains the most sustained and serious attack on mainstream, neoclassical economics in more than forty years. Nelson and Winter focus their critique on the basic question of how firms and industries change overtime. They marshal significant objections to the fundamental neoclassical assumptions of profit maximization and market equilibrium, which they find ineffective in the analysis of technological innovation and the dynamics of competition among firms. To replace these assumptions, they borrow from biology the concept of natural selection to construct a precise and detailed evolutionary theory of business behavior. They grant that films are motivated by profit and engage in search for ways of improving profits, but they do not consider them to be profit maximizing. Likewise, they emphasize the tendency for the more profitable firms to drive the less profitable ones out of business, but they do not focus their analysis on hypothetical states of industry equilibrium. The results of their new paradigm and analytical framework are impressive. Not only have they been able to develop more coherent and powerful models of competitive firm dynamics under conditions of growth and technological change, but their approach is compatible with findings in psychology and other social sciences. Finally, their work has important implications for welfare economics and for government policy toward industry.
"It is very exciting to see all of these studies compiled in one book. It can be read sequentially or just for certain transitions. It also can be used as a template for compilation of other concepts central to nursing and can serve as a resource for further studies in transitions. It is an excellent addition to the nursing literature." Score: 95, 4 Stars. --Doody's "Understanding and recognizing transitions are at the heart of health care reform and this current edition, with its numerous clinical examples and descriptions of nursing interventions, provides important lessons that can and should be incorporated into health policy. It is a brilliant book and an important contribution to nursing theory." Kathleen Dracup, RN, DNSc Dean and Professor, School of Nursing University of California San Francisco Afaf Meleis, the dean of the University of Pennsylvania School of Nursing, presents for the first time in a single volume her original "transitions theory" that integrates middle-range theory to assist nurses in facilitating positive transitions for patients, families, and communities. Nurses are consistently relied on to coach and support patients going through major life transitions, such as illness, recovery, pregnancy, old age, and many more. A collection of over 50 articles published from 1975 through 2007 and five newly commissioned articles, Transitions Theory covers developmental, situational, health and illness, organizational, and therapeutic transitions. Each section includes an introduction written by Dr. Meleis in which she offers her historical and practical perspective on transitions. Many of the articles consider the transitional experiences of ethnically diverse patients, women, the elderly, and other minority populations. Key Topics Discussed: Situational transitions, including discharge and relocation transitions (hospital to home, stroke recovery) and immigration transitions (psychological adaptation and impact of migration on family health) Educational transitions, including professional transitions (from RN to BSN and student to professional) Health and illness transitions, including self-care post heart failure, living with chronic illness, living with early dementia, and accepting palliative care Organization transitions, including role transitions from acute care to collaborative practice, and hospital to community practice Nursing therapeutics models of transition, including role supplementation models and debriefing models
This encyclopedia is the first major reference guide for students new to the field, covering traditional areas while pointing the way to future developments.
Niklas Luhmann's social theory stands in direct opposition to the dominant 'anthropocentric' traditions of legal and political analysis. King and Thornhill now offer the first comprehensive, critical examination of Luhmann's highly original theory of the operations of the legal and political systems. They describe how from the perspective of his 'sociological enlightenment' Luhmann continually calls to account the certainties, the ambitions and rational foundations of The Enlightenment and the idealized versions of law and politics which they have produced.
