An interactive component consumes a stream of input messages and produces a stream of output messages. The input/output behaviour describes the service offered by the component without disclosing the implementation. I...
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ISBN:
(纸本)9780769528670
An interactive component consumes a stream of input messages and produces a stream of output messages. The input/output behaviour describes the service offered by the component without disclosing the implementation. In general, an interactive component provides the contracted service only for a subset of input histories, called its service domain. We investigate the input/output behaviour of interactive components for erroneous input streams outside the service domain. We specify a fault sensitive behaviour, a fault tolerant behaviour, a robust behaviour, and a fault correcting behaviour by enlarging the regular behaviour in a systematic way. We implement the different behaviours by state transition machines where we enlarge the regular state space by additional information. Altogether we provide schematic transformations both on the specification and on the implementation level how to extend the regular behaviour of an interactive component to input streams outside the service domain. The resulting formal method separates the aspects of service provision and error handling in an orthogonal way.
The paper presents the top-down design of a synchronization component refining the communication-oriented. input/output behaviour into a state-based implementation. The component constrains the flow of messages on two...
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ISBN:
(纸本)9781424410309
The paper presents the top-down design of a synchronization component refining the communication-oriented. input/output behaviour into a state-based implementation. The component constrains the flow of messages on two parallel communication channels to stay within a specified tolerance. The formal derivation uses transformations which are of general importance for the design of interactive components. The differentiation of the stream function localizes the effect of a single input with respect to previous input histories. The history abstraction extracts the component's state from the input histories. The design safely bridges different views of the synchronization component ranging from the stream based specification to the state based implementation.
A combinational module for contiguous pattern matching tests whether the digits of a given pattern occur as a contiguous substring within a given search string. We present a unifying high-level synthesis of linear and...
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ISBN:
(纸本)9789889867140
A combinational module for contiguous pattern matching tests whether the digits of a given pattern occur as a contiguous substring within a given search string. We present a unifying high-level synthesis of linear and tree-structured combinational networks for contiguous pattern matching based on the theory of list homomorphisms. From a predicate logic specification, we develop standard implementations for tree-structured modules processing the input digits of the search string in parallel. The tree-structured design is systematically specialized to iterative networks processing the search string sequentially from left to right or vice versa. The formal design is parameterized with the type of digits to be matched. Throughout the paper, we explicate functional methods for the structured description of combinational circuits with higher-order list functions.
An interactive queue is a software component which stores data following a first-in / first out strategy. The regular behaviour of an interactive queue captures all input streams of enter-queue and de-queue commands w...
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ISBN:
(纸本)9789889867140
An interactive queue is a software component which stores data following a first-in / first out strategy. The regular behaviour of an interactive queue captures all input streams of enter-queue and de-queue commands which do not lead to a buffer underflow. We investigate the behaviour of interactive queues for input streams outside the service domain. We specify a fault sensitive queue, a fault tolerant queue, a robust queue, and a fault correcting queue as stream functions. We implement the different versions by state transition machines introducing a data state and a control state. Beyond the particular application, we provide adequate notions and high-level concepts for modeling services of interactive components in a functional setting.
A combinational module for scattered pattern matching tests whether the digits of a given pattern occur in the proper order and multiplicity within a given search string. We present a unifying high-level synthesis of ...
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We present the jABC, a framework for model driven application development based on Lightweight Process Coordination. With jABC, users (product developers and system/software designers) easily develop services and appl...
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ISBN:
(纸本)9783540708889
We present the jABC, a framework for model driven application development based on Lightweight Process Coordination. With jABC, users (product developers and system/software designers) easily develop services and applications by composing reusable building-blocks into hierarchical (flow-) graph structures that are executable models of the application. This process is supported by an extensible set of plugins providing additional functionalities, so that the jABC models can be animated, analyzed, simulated, verified, executed and compiled. This way of handling the collaborative design of complex software systems has proven to be effective and adequate for the cooperation of non-programmers and technical people, and it is now being rolled out in the operative practice.
Today web-based applications are very complex and provide several hundred users with access to sensible data. Adequate access control mechanisms that prevent unauthorized access and gives policy-compliant access to us...
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Developing security-critical applications is very difficult and the past has shown that many applications turned out to be erroneous after years of usage. For this reason it is desirable to have a sound methodology fo...
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The field of software engineering originally concentrated on "programming in the small" emphasizing implementation techniques. Over the last decades, software and systems engineering expanded to a comprehens...
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ISBN:
(纸本)0769529097
The field of software engineering originally concentrated on "programming in the small" emphasizing implementation techniques. Over the last decades, software and systems engineering expanded to a comprehensive engineering discipline. Nowadays software engineering comprises requirements engineering, modeling and design, implementation and testing, installation and maintenance. software engineering proved to be a key technology;its mastery determines the functioning of modern infrastructures and consumer products. software development has matured from heuristic practice to an engineering discipline. In the meantime, software engineers can benefit from a solid stock of basic research addressing modeling and design techniques for sequential, concurrent, distributed, and timed systems. software quality and reliability, security and safety, the management of change, reuse and integration pose new requirements to the practice of software engineering. A major challenge consists in integrating the developed theories into a coherent engineering framework accepted by practitioners. software engineers face different system views described by a variety of graphical and textual formalisms. software development must safely bridge the system views on different levels of abstraction ranging from high-level specifications to executable code. The system views center around the data model, the communication model, the state transition model, and the trace model. The data model describes the data structure in an abstract or concrete way. The communication model manifests how a component interacts with the environment by exchanging messages. The state transition model describes an abstract implementation where an input affects an update of the internal state and a possible output. The trace model characterizes the operational behaviour of the system by a set of possible runs composed of atomic actions. The lecture classifies different system models and addresses discrete interactive sys
Shape-generic programming and high run time performance do match if generic source code is systematically specialised into nongeneric executable code. However, as soon as we drop the assumption of whole-world knowledg...
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