49,565 research outputs found

    Empowering Collections with Swarm Behavior

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    Often, when modelling a system there are properties and operations that are related to a group of objects rather than to a single object. In this paper we extend Java with Swarm Behavior, a new composition operator that associates behavior with a collection of instances. The lookup resolution of swarm behavior is based on the element type of a collection and is thus orthogonal to the collection hierarchy

    Object-Oriented Paradigms for Modelling Vascular\ud Tumour Growth: a Case Study

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    Motivated by a family of related hybrid multiscale models, we have built an object-oriented framework for developing and implementing multiscale models of vascular tumour growth. The models are implemented in our framework as a case study to highlight how object-oriented programming techniques and good object-oriented design may be used effectively to develop hybrid multiscale models of vascular tumour growth. The intention is that this paper will serve as a useful reference for researchers modelling complex biological systems and that these researchers will employ some of the techniques presented herein in their own projects

    An empirical investigation of an object-oriented software system

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    This is the post print version of the article. The official published version can be obtained from the link below.This paper describes an empirical investigation into an industrial object-oriented (OO) system comprised of 133,000 lines of C++. The system was a subsystem of a telecommunications product and was developed using the Shlaer-Mellor method. From this study, we found that there was little use of OO constructs such as inheritance and, therefore, polymorphism. It was also found that there was a significant difference in the defect densities between those classes that participated in inheritance structures and those that did not, with the former being approximately three times more defect-prone. We were able to construct useful prediction systems for size and number of defects based upon simple counts such as the number of states and events per class. Although these prediction systems are only likely to have local significance, there is a more general principle that software developers can consider building their own local prediction systems. Moreover, we believe this is possible, even in the absence of the suites of metrics that have been advocated by researchers into OO technology. As a consequence, measurement technology may be accessible to a wider group of potential users

    Object oriented design of a thermo-mechanical FEM code

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    An object oriented design is presented for a computer program that can perform\ud thermo-mechanically coupled analyzes. The target of the design is a \ud exible and robust\ud computer program. It should be easy to adapt and extend, re-using existing code, without\ud interfering with already established algorithms.\ud The program uses publicly available toolkits that are currently emerging as C++ pack-\ud ages. First of all the Standard C++ Library (formerly Standard Template Library) is\ud used for packing items in container classes. Secondly the matrix and vector operations\ud are derived from the Template Numerical Toolkit (TNT) and ïżœnally (not essentially for\ud the numerical part) a graphical user interface is made, based on the wxWindows package,\ud that can generate a GUI for Motif and MS-Windows with the same code.\ud Attention is given to the design of classes such as speciïżœc elements and material classes\ud based on more general classes. A hierarchy of classes is constructed where general behavior\ud is put high in the hierarchy and speciïżœc behavior low. The choice between inheritance and\ud aggregation is made at several levels

    Economic Boom and Social Mobility: The Irish Experience

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    In this paper we examine the consequences for social mobility patterns of the unprecedented period of economic growth experienced in Ireland over the 1990s and the implications of developments for current theories of social fluidity. Contrary to suggestions that the ?Celtic Tiger? experience has been associated with a deepening problem of marginalization we found evidence for a substantial upgrading of the class structure and increased levels of social mobility. We also found evidence for increased social fluidity in relation to long-range hierarchical mobility. Such increased openness could not be explained by changes in the manner in which education mediates the relationship between origins and destinations. There is no necessary relationship between economic growth and social fluidity. However, the pattern of change over time in the Irish case suggests that both long-term factors associated with the upgrading of the class structure and short-term factors reflected in the unprecedented tightness of the labour market have produced a situation where employers have increasingly applied criteria other than education in a manner that has facilitated increased social fluidity. The Irish case provides further support to the argument for reconsidering the balance that mobility research has struck between social fluidity and absolute mobility and encouraging increased attention to the evolution of firms and jobs. It also provides support for the conclusion, that in circumstances where policies in advanced industrial societies have shown an increasing tendency to diverge, increased social fluidity may come about as a consequence of very different economic and social policies.

    Multimethods and separate static typechecking in a language with C++-like object model

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    The goal of this paper is the description and analysis of multimethod implementation in a new object-oriented, class-based programming language called OOLANG. The implementation of the multimethod typecheck and selection, deeply analyzed in the paper, is performed in two phases in order to allow static typechecking and separate compilation of modules. The first phase is performed at compile time, while the second is executed at link time and does not require the modules' source code. OOLANG has syntax similar to C++; the main differences are the absence of pointers and the realization of polymorphism through subsumption. It adopts the C++ object model and supports multiple inheritance as well as virtual base classes. For this reason, it has been necessary to define techniques for realigning argument and return value addresses when performing multimethod invocations.Comment: 15 pages, 18 figure
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