this paper describes an experiment to assess the impact of inheritance on the modifiability of object-oriented business domain models. this experiment is part of a research project on the quality determinants of early...
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ISBN:
(纸本)0769510280;0769510299
this paper describes an experiment to assess the impact of inheritance on the modifiability of object-oriented business domain models. this experiment is part of a research project on the quality determinants of early systems development artefacts, with a special focus on the maintainability of business domain models. Currently there is little empirical information about the relationship between the size, structural and behavioural properties of business domain models and their maintainability. the situation is different in object-oriented softwareengineering where a number of experimental investigations into the maintainability of object-oriented software have been conducted. the results of our experiment indicate that extensive nse of inheritance leads to models that are more difficult to modify. these findings are in line withthe conclusions drawn from three similar controlled experiments on inheritance and modifiability of object-oriented software.
Despite natural language's well-documented shortcomings as a medium for precise technical description, its use in software-intensive systemsengineering remains inescapable. this poses many problems for engineers ...
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ISBN:
(纸本)3540419438
Despite natural language's well-documented shortcomings as a medium for precise technical description, its use in software-intensive systemsengineering remains inescapable. this poses many problems for engineers who must derive problem understanding and synthesise precise solution descriptions from free text. this is true both for the largely unstructured textual descriptions from which system requirements are derived, and for more formal documents, such as standards, which impose requirements on system development processes. this paper describes experiments that we have carried out in the REVERE1 project to investigate the use of probabilistic natural language processing techniques to provide systemsengineering support.
For around three decades softwareengineering gurus have "sold" us the ideal of minimal coupling and maximal cohesion at all levels of abstraction as a way to reduce the effort to understand and maintain sof...
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For around three decades softwareengineering gurus have "sold" us the ideal of minimal coupling and maximal cohesion at all levels of abstraction as a way to reduce the effort to understand and maintain softwaresystems. the object-oriented paradigm brought a new design philosphy and encapsulation mechanisms that apparently would help us to achieve that desideratum. However, after a decade where this paradigm has emerged as the dominant one, we are faced with practitioners' reality: coupling and cohesion do not seem to be the dominant driving forces when it comes to modularization. this conclusion was based on a relatively large sample of heterogeneous systems. We describe an environment that allows not only assessing this reality but also deriving better modularization solutions in what concerns coupling and cohesion. these solutions are generated by means of cluster analysis techniques and partially preserve the original modularization criteria. We believe this approach can be of great help in reengineering actions of object-oriented legacy systems.
Database reverse engineering (DBRE) attempts to recover the technical and semantic specifications of the persistent data of information systems. Dependencies between records (data dependency) form a major class that n...
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Database reverse engineering (DBRE) attempts to recover the technical and semantic specifications of the persistent data of information systems. Dependencies between records (data dependency) form a major class that need to be recovered. Since most of these dependencies are not supported by the DBMS, (foreign keys are the main exception, at least in modern relational DBMS), they have not be explicitly declared in the database schema. Careless reverse engineering will inevitably ignore them, leading to poor quality conceptual schema. Several information sources can contribute to the elicitation of these hidden dependencies. the program source code has long been considered the richest, but also the most complex, fibers. In this paper we analyze and compare, through their respective quality and cost, different program understanding techniques that can be used to elicit data dependencies.
the paper introduces a Switched Reluctance motor drive system for locomotive in coal mines based on 80C31 single chip computer control. the schemes of the turn-on angle and the turn-off angle of the main switches in t...
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ISBN:
(纸本)7506251159
the paper introduces a Switched Reluctance motor drive system for locomotive in coal mines based on 80C31 single chip computer control. the schemes of the turn-on angle and the turn-off angle of the main switches in the power converter at the condition of traction and at the condition of regenerative braking are advanced. the principles of the traction velocity control and the braking torque control are given. the pattern of the hardware and the software in the 80C31 single chip computer control system are presented.
Identifying a matching component is a recurring problem in softwareengineering, specifically in software reuse. Properly generalized, it can be seen as an information retrieval problem. In the context of defining the...
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Resource awareness is an important step towards the realization of adaptable software, something which is particularly desirable in the context of mobile code and mobile agent environments. Since resources (CPU, memor...
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Technology literacy for all on one hand and continuous demand for skilled technology engineers and workers on the other hand, poses a challenge to education systems worldwide. Recent years show efforts to integrate te...
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Technology literacy for all on one hand and continuous demand for skilled technology engineers and workers on the other hand, poses a challenge to education systems worldwide. Recent years show efforts to integrate technology into all levels of the school curriculum. the work presented here introduces one possible approach to familiarize 5th to 6th grade pupils with high level technology using a mobile robot as the principal tool in the curriculum. Children construct an open ended, autonomous robot while working in teams (6 per team). Each team is divided into sub-groups that represent the various skills needed for the construction and operation of the robot. they use a flow-chart software as their programming frame. At first, the teams are given simple missions, and as they progress, they are challenged with open-ended, more complex assignments. Each weekly session lasts about three hours of which a third is devoted to knowledge expansion and the rest for testing and construction. During the test phase, pupils perform experiments for deducing device properties (sensor, motor, control method, etc.). they add the device of their choice to their mobile robot system. As a typical open-ended problem, the team explores possible solutions to each problem. then they are expected to define their solutions and implement them. At the end of the year there is a contest between robots built by the various teams, to accomplish a predefined task.
this study developed a multi-user 3D virtual environment system. the system must achieve two goals: - Portability: it can be embedded to any kind of platform. - Coherence with other system: it can reuse shared objects...
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