object-oriented techniques such as inheritance promise great benefits for the specification and design of concurrent systems. To exploit these benefits appropriate techniques for object-orientedprogramming within a c...
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ISBN:
(纸本)3540645365
object-oriented techniques such as inheritance promise great benefits for the specification and design of concurrent systems. To exploit these benefits appropriate techniques for object-orientedprogramming within a concurrent programming language context are required. Especially a concept how to support the inheritance of synchronization constraints is necessary to avoid what is called the inheritance anomaly. We present a modelling style of Ada which allows the integration of concurrency into object-orientedprogramming and which offers a solution to the inheritance anomaly.
The TT1 (Toppo Telescope #1) is a 1.54 m Alt-Az telescope designed and built by the Technology Working Group (TWG) of the Astronomical Observatory of Capodimonte (OAC), Naples Italy. The standardization process is of ...
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ISBN:
(纸本)0819427985
The TT1 (Toppo Telescope #1) is a 1.54 m Alt-Az telescope designed and built by the Technology Working Group (TWG) of the Astronomical Observatory of Capodimonte (OAC), Naples Italy. The standardization process is of course one of the fundamental requirements for telescope control system design and development, well considered in the TT1design. In this paper we present the approach used to identify a control system applicable to medium-size Alt-Az telescope. The TT1 control system architecture is based on a distributed working flow and it is PC-based, i.e. organized in several interconnected standard PCs and standard fast communication protocol. Every PC is based on the "dedicated processing unit" concept and it makes real time own tasks independently by other units. Also, the extremely reduced communication flow between PCs, and their internal organization based on the preference given to software rather than hardware solutions, makes its control system extremely reliable, easily reconfigurable and upgradable, obsolescence deprived and independent from any hardware choice.
Reuse in polymorphic systems strongly depends on correct use of inheritance. There have been many efforts to check whether or not subtyping is correct. All of these approaches either, restrict the use of inheritance c...
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ISBN:
(纸本)0818684828
Reuse in polymorphic systems strongly depends on correct use of inheritance. There have been many efforts to check whether or not subtyping is correct. All of these approaches either, restrict the use of inheritance customize the class hierarchies in an application specific way or use proof theoretical techniques. This is often too restrictive or even impossible - at least for practical use. In order to provide both -flexibility and robustness - this paper introduces the concept of weak conformance. This concept allows the specification of specialized classes that may be used in a polymorphic context. The main idea is to check conformance in the context of a concrete application. Furthermore, the paper demonstrates how the proposed concept can easily be integrated into ally programming language and introduces an algorithm for checking robustness of an application. This algorithm detects all critical and illegal polymorphic method calls that may violate the robustness. Finally the paper discusses ways of how to handle critical calls, i.e. calls that can be proven correct by the developer bur not by the type system.
In this paper we show how software are architectural styles can be used to guide object-oriented design. Design guidance is important as the initial phases of software, design significantly impact software quality. We...
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ISBN:
(纸本)0769500536
In this paper we show how software are architectural styles can be used to guide object-oriented design. Design guidance is important as the initial phases of software, design significantly impact software quality. We use two different architectural styles to guide the design process from a formal specification to a design. Software architectural styles assist by providing a different level of reuse than currently practised in software design. A style provides a framework for top-level structure and guides selection of components and interfaces. In this paper we show the impact of software architectural styles on software design.
FlexiInternational develops and maintains FlexiFinancials, a suite of object-oriented, client/server software products for accounting. These interacting applications support general ledger, accounts payable and receiv...
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ISBN:
(纸本)0780351584
FlexiInternational develops and maintains FlexiFinancials, a suite of object-oriented, client/server software products for accounting. These interacting applications support general ledger, accounts payable and receivable, purchasing, fixed assets, order processing, inventory maintenance, and workflow functions. This paper describes a distributed component, transaction-based architecture that comprises the foundation for future development.
To teach object-orientedprogramming skills effectively, it is necessary to give examples of interesting problems solved in a step-by-step manner and to focus on the design considerations that a skilled programmer app...
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To teach object-orientedprogramming skills effectively, it is necessary to give examples of interesting problems solved in a step-by-step manner and to focus on the design considerations that a skilled programmer applies. An example of object thinking in solving a 'rat maze' problem is presented. The problem is first described, then a first-cut solution is presented. The demerits of the solution are discussed, and finally, an improved solution is presented. More examples of this type of problem solving are necessary to effectively teach object thinking.
The pi-calculus provides a formal foundation for processes with dynamic interaction structures, appropriate for modeling concurrent systems with changing network topologies, and mobile agents. Not surprisingly then, i...
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ISBN:
(纸本)0818684852
The pi-calculus provides a formal foundation for processes with dynamic interaction structures, appropriate for modeling concurrent systems with changing network topologies, and mobile agents. Not surprisingly then, it has attracted the interest of researchers wishing to formalize models for concurrent object systems. To date, most such models have been object-based In this paper we present a class-based model in the pi-calculus, which captures both the semantics of method sharing for classes, as well as multiple inheritance.
Various types of diagrams are used to represent the design of software systems. During the design phase, versions of a diagram may be created like other design documents and source code, and it is necessary to manage ...
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ISBN:
(纸本)0818691832
Various types of diagrams are used to represent the design of software systems. During the design phase, versions of a diagram may be created like other design documents and source code, and it is necessary to manage them efficiently. However, traditional configuration management systems and some object-oriented database management systems that provide object versioning are nor suitable for managing versions of a diagram. In this paper, we propose an efficient version model of software diagrams. This model reflects the common characteristics and structure of software diagrams, and revisions of a diagram are managed by operation delta and object visibility. A merge model for versions of a diagram is also presented at the end of this paper.
object-oriented (OO) classes are generally not reusable because they are not meaningful in isolation;most classes only have meaning as members of cooperating suites of classes (e.g., design patterns). These suites usu...
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ISBN:
(纸本)0818683775
object-oriented (OO) classes are generally not reusable because they are not meaningful in isolation;most classes only have meaning as members of cooperating suites of classes (e.g., design patterns). These suites usually arise in designs, but rarely exist as encapsulated entities in 00 implementations. In this paper we present a method for directly mapping cooperating suites of classes into encapsulated C++ implementations. Our method is an improvement over the VanHilst and Notkin approach for implementing collaboration-based designs and constitutes a step towards more reusable (object-oriented) components.
objectoriented sofware engineering (OOSE) is becoming a common approach to software development. As third generation OOSE processes are established leg. OPEN [1] and the Unified Sofware are Development Process [21]) ...
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ISBN:
(纸本)0769500536
objectoriented sofware engineering (OOSE) is becoming a common approach to software development. As third generation OOSE processes are established leg. OPEN [1] and the Unified Sofware are Development Process [21]) organisations will start to consider OOSE as a mature technology. This recognition will mean that more organisations will go through the process of changing their current software development processes. This paper will report on the experience of one team at a large technical firm as they adopted OOSE precesses for a major project. The experience of this team confirms most of what has been previously reported in the literature, and adds two additional observations. The first observation is that other literature in this field does not consider team,motivation as a factor that contributes to migration success. The second observation is that other literature does not consider the relative impact oof some factors over other factors.
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