Intheworldweliveinconcurrencyisthenorm.Forexample,thehumanbody isamassivelyconcurrentsystem,comprisingahugenumberofcells,allsim- taneously evolving and independently engaging in their individual biological processing.Inaddition,inthebiologicalworld,trulysequentialsystemsrarely arise. However, they are more common when manmade artefacts are cons- ered. In particular, computer systems are often developed from a sequential perspective. Why is this? The simple reason is that it is easier for us to think about sequential, rather than concurrent, systems. Thus, we use sequentiality as a device to simplify the design process. However, the need for increasingly powerful, ?exible and usable computer systems mitigates against simplifying sequentiality assumptions. A good - ample of this is the all-powerful position held by the Internet, which is highly concurrent at many di?erent levels of decomposition. Thus, the modern c- puter scientist (and indeed the modern scientist in general) is forced to think aboutconcurrentsystemsandthesubtleandintricatebehaviourthatemerges from the interaction of simultaneously evolving components. Over a period of 25 years, or so, the ?eld of concurrency theory has been involved in the development of a set of mathematical techniques that can help system developers to think about and build concurrent systems. These theories are the subject matter of this book.

This book presents the leading edge in several related fields, specifically object orientated programming, open distributed systems and formal methods for object oriented systems. With increased support within industry regarding these areas, this book captures the most up-to-date information on the subject. Many topics are discussed, including the following important areas: object oriented design and programming; formal specification of distributed systems; open distributed platforms; types, interfaces and behaviour; formalisation of object oriented methods.

Originally published in 2002, this book presents techniques in the application of formal methods to object-based distributed systems. A major theme of the book is how to formally handle the requirements arising from OO distributed systems, such as dynamic reconfiguration, encapsulation, subtyping, inheritance, and real-time aspects. These may be supported either by enhancing existing notations, such as UML, LOTOS, SDL and Z, or by defining fresh notations, such as Actors, Pi-calculus and Ambients. The major specification notations and modelling techniques are introduced and compared by leading researchers. The book also includes a description of approaches to the specification of non-functional requirements, and a discussion of security issues. Researchers and practitioners in software design, object-oriented computing, distributed systems, and telecommunications systems will gain an appreciation of the relationships between the major areas of concerns and learn how the use of object-oriented based formal methods provides workable solutions.

Intheworldweliveinconcurrencyisthenorm.Forexample,thehumanbody isamassivelyconcurrentsystem,comprisingahugenumberofcells,allsim- taneously evolving and independently engaging in their individual biological processing.Inaddition,inthebiologicalworld,trulysequentialsystemsrarely arise. However, they are more common when manmade artefacts are cons- ered. In particular, computer systems are often developed from a sequential perspective. Why is this? The simple reason is that it is easier for us to think about sequential, rather than concurrent, systems. Thus, we use sequentiality as a device to simplify the design process. However, the need for increasingly powerful, ?exible and usable computer systems mitigates against simplifying sequentiality assumptions. A good - ample of this is the all-powerful position held by the Internet, which is highly concurrent at many di?erent levels of decomposition. Thus, the modern c- puter scientist (and indeed the modern scientist in general) is forced to think aboutconcurrentsystemsandthesubtleandintricatebehaviourthatemerges from the interaction of simultaneously evolving components. Over a period of 25 years, or so, the ?eld of concurrency theory has been involved in the development of a set of mathematical techniques that can help system developers to think about and build concurrent systems. These theories are the subject matter of this book.

This important resource presents the current state of the art in the application of formal methods to object based distributed systems. A major theme is how to formally handle the new requirements arising from OO distributed systems. The major specification notations and modeling techniques are introduced and compared by leading researchers, in several cases, the inventors of the notations. The book also describes approaches to the specification of nonfunctional requirements, needed typically in the specification of multimedia systems and security issues. Professionals in software design, object-oriented computing, distributed systems, and telecommunications systems will gain an appreciation of the relationships among the major areas of concerns and learn how the use of object-oriented based formal methods provides workable solutions.

Lasse Hallstrom directs this romantic drama based on the novel by Nicholas Sparks. While Special Forces Army Sergeant John Tyree (Channing Tatum) is home on leave, he meets beautiful college student Savannah Curtis (Amanda Seyfried) and the two fall in love. When the time comes for Savannah to return to college, she promises to write to John during his 12-month enlistment overseas. However, their budding love affair is put to the test when John decides to re-enlist in the wake of the 9/11 attacks.