Generalized nets (GN) are created as a tool for modeling and controlling real processes. The mathematical tools which GNs have make them an effective and convenient instrument for software modeling. Models of software...
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ISBN:
(纸本)9781467322768
Generalized nets (GN) are created as a tool for modeling and controlling real processes. The mathematical tools which GNs have make them an effective and convenient instrument for software modeling. Models of software systems can be created by means of GN;specifications of properties, connections between software modules, relations between classes and member functions of classes can be defined;properties of software systems can be proven. The paper describes an application of the GN for building models of programs, for defining specifications, describing properties and relationships between program units, for verification of object-oriented programs (OOP). An approach for verification of OOP is presented from methodological point of view. The approach is intended for research and educational purposes.
2007 presents I jubilee of 40 years of the object-oriented programming (OOP). In the paper. the importance of computer simulation for discovering OOP is explained, together with the development from process-oriented s...
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ISBN:
(纸本)9789077381366
2007 presents I jubilee of 40 years of the object-oriented programming (OOP). In the paper. the importance of computer simulation for discovering OOP is explained, together with the development from process-oriented simulation languages up to SIMULA 67 and behind and above the paradigm called OOP.
A designing of digital circuits is based on hardware description languages (HDLs). The dominating standard of HDLs is the VEDL, which basing on a digital circuit structure, a net-list, and an event-driven algorithm. I...
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ISBN:
(纸本)9788392263241
A designing of digital circuits is based on hardware description languages (HDLs). The dominating standard of HDLs is the VEDL, which basing on a digital circuit structure, a net-list, and an event-driven algorithm. In the publication is presented a description of the digital circuit built in an object-oriented programming. The base assumptions of a description are a digital circuit diagram and an event-driven algorithm. The descriptions are expressed in terms of the C#. A first part of the method based on a conception, which is widely published. A second part of the method is our conception of implementing an event-driven algorithm, using "a reformulating"..
We present the Program by Design introductory CS curriculum through the lenses of graphics, animations, algebra, and data structures. Animations programming is popular for CS1, but many such curricula lack clean paths...
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ISBN:
(纸本)9781450310987
We present the Program by Design introductory CS curriculum through the lenses of graphics, animations, algebra, and data structures. Animations programming is popular for CS1, but many such curricula lack clean paths into CS2. Program by Design is different. Using and reinforcing concepts from algebra, students learn to write animations (including standard topics such as model/view separation and event-handling), then move seamlessly into working with structured data, lists, trees, and objects. The curriculum emphasizes design, testing, and writing maintainable programs, without losing the engagement of animations. The workshop uses lectures and hands-on exercises to provide high- school and college teachers an overview of the approach. See ***. Laptop Optional.
Late binding and subtyping create run-time overhead for object-oriented languages, especially in the context of both multiple inheritance and dynamic loading, for instance for JAVA interfaces. In a previous article, w...
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Late binding and subtyping create run-time overhead for object-oriented languages, especially in the context of both multiple inheritance and dynamic loading, for instance for JAVA interfaces. In a previous article, we proposed a novel approach based on perfect hashing and truly constant-time hashtables for implementing subtype testing and method invocation in a dynamic loading setting. In this first study, we based our efficiency assessment on Driesen's abstract computational model for the time aspect, and on large-scale benchmarks for the space aspect. The conclusions were that the technique was promising but required further research in order to assess its scalability. This article presents some new results on perfect class hashing that enhance its interest. We propose and test both new hashing functions and an inverse problem that amounts to selecting the best class identifiers in order to minimize the overall hashtable size. This optimizing approach is proven to be optimal for single-inheritance hierarchies. Experiments within an extended testbed with random class loading and under cautious assumptions about what should be a sensible class-loading order show that perfect class hashing scales up gracefully, especially on JAVA-like multiple-subtyping hierarchies. Furthermore, perfect class hashing is implemented in the PRM compiler testbed, and compared here with the coloring technique, which amounts to maintaining the single-inheritance implementation in multiple inheritance. The overall conclusion is that the approach is efficient from both time and space standpoints with the bit-wise and hashing function. In contrast, the poor time efficiency of modulus hashing function on most processors is confirmed. Copyright (C) 2010 John Wiley & Sons, Ltd.
The recent trend in distributed automation and control systems has been towards event-triggered system architectures such as UML and IEC 61499. Although existing communication protocols (e.g., Ethernet) can support hi...
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The recent trend in distributed automation and control systems has been towards event-triggered system architectures such as UML and IEC 61499. Although existing communication protocols (e.g., Ethernet) can support high-level communication within these systems, there is contention as to which low-level protocol to use, or if any exist that meet the requirements of being event-triggered and hard real-time. This paper proposes a new way to measure communication performance. The goal of the new measurement method is to stress the necessity that a real-time communication protocol needs to be both efficient and fair. This is illustrated by comparing three communication strategies: Controller Area Network (CAN), Time-Triggered CAN (TTCAN) and Escalating Priority CAN (EPCAN). The first two represent the extremes between event-triggered and time-triggered communication strategies;the third is introduced to illustrate the benefits of a new event-based communication protocol proposed by the authors. (c) 2010 Elsevier Ltd. All rights reserved.
Program slicing is a decomposition technique that deals with extracting those statements relevant to a particular computation. The authors propose a novel algorithm for computing dynamic slice of distributed object-or...
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Program slicing is a decomposition technique that deals with extracting those statements relevant to a particular computation. The authors propose a novel algorithm for computing dynamic slice of distributed object-oriented programs. The proposed algorithm incorporates graph colouring strategy to compute slice. But to achieve the goal efficiently, the authors have contradicted some key constraints of the traditional graph colouring technique. The state restriction of the slicing criterion is also considered along with dependence analysis while computing slice. The advantage of the proposed algorithm is that it is efficient and faster than the existing algorithms.
The aim of the paper is to investigate applicability of object-oriented software design patterns in the context of aspect-oriented design. The paper analyses which of the GoF 23 patterns have a meaning in this context...
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The aim of the paper is to investigate applicability of object-oriented software design patterns in the context of aspect-oriented design. The paper analyses which of the GoF 23 patterns have a meaning in this context and how they are affected by it. The main assumption is that there exist design patterns that solve software engineering paradigm independent design problems and that such patterns, in the contrast to the patterns solving paradigm-specific design problems, can be expressed in terms of any software engineering paradigm. However, the paper deals only with two paradigms: aspect-oriented (AO) paradigm and object-oriented (OO) paradigm. It proposes a classification of design problems based on this assumption and a technique for redesigning object-oriented patterns into pure aspect-oriented ones. It presents a number of examples how to apply this technique and discusses the results obtained. The results show that 20 of the GoF 23 design patterns solve such design problems that are common at least for both mentioned paradigms and demonstrate in which way these patterns can be adapted for the needs of aspect-oriented design.
Software metrics should be used in order to improve the productivity and quality of software, because they provide critical information about reliability and maintainability of the system. In this paper, we propose a ...
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Software metrics should be used in order to improve the productivity and quality of software, because they provide critical information about reliability and maintainability of the system. In this paper, we propose a cognitive complexity metric for evaluating design of object-oriented (OO) code. The proposed metric is based on an important feature of the OO systems: Inheritance. It calculates the complexity at method level considering internal structure of methods, and also considers inheritance to calculate the complexity of class hierarchies. The proposed metric is validated both theoretically and empirically. For theoretical validation, principles of measurement theory are applied since the measurement theory has been proposed and extensively used in the literature as a means to evaluate the software engineering metrics. We applied our metric on a real project for empirical validation and compared it with Chidamber and Kemerer (CK) metrics suite. The theoretical, practical and empirical validations and the comparative study prove the robustness of the measure.
The article focuses on the development of an OPC UA (object linking and embedding (OLE) for process control unified architecture) server. One of the major concerns regarding this new specification is the migration fro...
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The article focuses on the development of an OPC UA (object linking and embedding (OLE) for process control unified architecture) server. One of the major concerns regarding this new specification is the migration from the old component object model (COM) to the new UA specification. From the various migration strategies described in this article, the authors' server represents a special adapter software solution which aggregates several COM servers, one for each flexible manufacturing system (FMS) modelled in the address space of the UA server. The article focuses on the advantages introduced by the new specification like the unified modelling capability and the extensible meta model. The address space is exemplified by means of a screw fitting station, which is part of the flexible line, on which the UA server has been tested. From the four generally accepted use cases, the server implements the first two: observation and control. They are mainly supported through the variables and the methods of the address space. During the testing phase, the minimum sampling interval regarding the communication with the underlying COM servers has been determined for a different number of FMSs. As a result the special adapter software solution is a fast but also a well-performing approach, which works well even in very complex environments.
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