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Software engineering has been facing a crisis for several years now - there is more demand for new software than there is ability to supply. Software reuse is a potential way to tackle the problems caused by the software crisis with its promises of increased productivity and cheaper development costs. Several software reuse successes have been reported, but these have been predominantly in large, well structured companies. However, there are numerous smaller companies that could also benefit from reuse if it were made available to them. This thesis addresses these issues by implementing a reuse programme in a small company. An incremental approach to reuse introduction is adopted, following the Seven Steps to Success, and 'lightweight' processes are recommended to support the reuse programme. A prototype tool set, ReThree- C++, was developed to automate support for the reuse programme. The results of the case study are presented. The reuse programme was successful, with benefits to the company including both increased speed of production and financial gains from selling reusable components. The challenges faced are also identified. Details of the tool set giving automated support for reuse are also presented. The tool set is an approach to reuse repository control which also integrates information abstraction from C++ source code to generate class hierarchy charts and software documentation automatically. It helps developers store, retrieve, understand and use reusable components. The usefulness of the tool set is shown with an experiment and as part of the case study. The purpose of the thesis is to show that small companies can implement reuse, and that the method presented supports the introduction of a reuse programme. It concludes that although challenges were faced, great benefits can be gained by using the method with automated support for reuse in a small company.

Telecommunication technologies and networks are constantly changing; with the introduction of the GSM system the shift from wired to wireless telephony experienced a unique boom. Since then, behaviour and communication needs of users (i.e. subscribers) have undergone rapid changes from initially the need for pure wireless voice transmission to now data and multimedia content traffic. Introduction of the 3rd Generation (UMTS/IMT 2000) promised the delivery of these services and the integration with the Internet. However, legacy technologies and networks are not likely to be replaced soon, the different wireless and wired communication and information infrastructures will co-exist and will have to work, seemingly seamless, together. The here documented research work delivers basic mechanisms supporting this integration, therefore a variety of technologies from different areas, ranging from Software Radio technology to Object-Oriented computing, have been brought together to introduce reconfigurability to mobile communication networks. Distributed object computing technologies are evaluated and their application as signalling and support platforms for reconfigureable systems is shown in different examples. Other novelties are the introduction of a protocol for download of reconfiguration software, from various software sources, these sources include Smart Cards, wired outlets and Over-The-Air. Furthermore, an object-oriented framework for flexible, 'on-the-fly' protocol exchange has been developed; the mechanisms and architecture of this framework are described within this thesis. Combining protocol reconfiguration, software download and distributed platforms and focusing on control and management of reconfiguration have led to the design and definition of a reconfiguration management architecture. Functionality and structure of this architecture are documented, and its single modules are described. Providing means and mechanisms enabling management and control of reconfiguration within reconfigureable mobile communication networks is the purpose of this thesis. KM, Guildford, July 2001 Key words: reconfiguration, reconfiguration management. Software Radio, object-orientation, middleware, CORBA, Universal Control CHannel.

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<p><p>The use of examples is known to be important in learning, they should be “exemplary” and function as role-models.</p><p>Teaching and learning problem solving and programming in the object oriented paradigm is recognised as difficult. Object orientation is designed to handle complexity and large systems, and not with education in focus. The fact that object orientation often is used as first paradigm makes the design of examples even more difficult and important.</p><p>In this thesis, a survey of the literature is made to establish a set of characteristics for object orientation in general. This set of characteristics is then applied to the educational setting of introducing novices to object oriented problem solving and programming, resulting in a number of heuristics for educational purposes, called He[d]uristics. The proposed He[d]uristics are targeted towards educators designing small-scale examples for novices, and is an attempt to provide help in designing suitable examples, not a catalogue of good ones.</p><p>The He[d]uristics are discussed and exemplified and also evaluated versus the derived set of characteristics and known common problems experienced by novices.</p></p>

Abstract This thesis examines and evaluates the Object-Oriented Client/Server (OOCS) model, a process model that can be used when IT organizations develop object-oriented client/server applications. In particular, it defines the roles in the development team and combines them into the process model. Furthermore, the model focuses on the client/server architecture, considering it explicitly. The model has been under construction for several years and it has been tested in a number of industrial projects. Feedback from practice has thus been an important source when the model has been evolving into its current form. Another source for evolution has been other process models and technical progress in this field. This thesis reveals the theoretical and practical aspects that have influenced the model's characteristics and developmnt. The object-oriented paradigm has been the driving force when creating the OOCS model. The first object-oriented development models were, however, both inadequate and contradictory to each other. The OOCS model utilizes the best practices from these early models. The model also defines artifacts to be delivered in each phase. The artifacts are synchronized with the Unified Modeling Language (UML), a new standard modeling notation. From the very beginning the OOCS model has included a strong client/server viewpoint, which is not stated so clearly in other object-oriented models. A three-tier division of the application (presentation, business logic, data management) can be found in each phase. This division has become crucial in recent years, when applications have been built on distributed architecture. The team-based roles included in the model are based on the work of a few other researchers, although this topic has not gained the importance it should have had. Namely, it is people that develop the application and their involvement in the process should be stated explicitly. The roles of the developers are closely connected to the OOCS process model via the concept of activities included in the model. The roles concentrate mainly on project members, but company-level aspects have also been considered. This thesis summarizes the work carried out in the last five years. It shows how the model has evolved in practice and how other models have contributed to it. The team-based OOCS model is in use in some IT organizations. The cases presented in this thesis illustrate how to adapt the model into specific organizational needs.

<p>Relationships between classes and objects in object-oriented software are necessary in order for the parts of the systems to provide dynamic behavior. These inherent relationships also create dependencies which can give rise to problems for software evolution of object-oriented software systems. Dependencies in software make systems difficult to understand, reuse, change and verify.</p><p>This thesis presents analytical and empirical investigations of dependency-related problems in software evolution of object-oriented software and on how such problems can be handled with dependency focused techniques, methods and processes.</p><p>The research presented in this thesis includes: Development of a programming language construct for controlling dependencies; formal experiments on code inspection techniques; exploring change strategies' effects on test suites; an industrial case study of regression test selection techniques for object-oriented software; proving the efficiency and defect detection capabilities of a novel regression test selection technique.</p><p>The thesis contributes to increased knowledge on the role of dependencies in software evolution of object-oriented software. Specific contributions are a programming language construct that can control access to dependencies in software. Other main contributions are insights on the efficiency of dependency focused code inspection techniques and contribution to the knowledge on dependency-based regression test selection techniques for large scale software. Another contribution is a novel change-based regression test selection technique.</p>

Sandwich covariance matrix estimators are a popular tool in applied regression modeling for performing inference that is robust to certain types of model misspecification. Suitable implementations are available in the R system for statistical computing for certain model fitting functions only (in particular lm()), but not for other standard regression functions, such as glm(), nls(), or survreg(). Therefore, conceptual tools and their translation to computational tools in the package sandwich are discussed, enabling the computation of sandwich estimators in general parametric models. Object orientation can be achieved by providing a few extractor functions-most importantly for the empirical estimating functions-from which various types of sandwich estimators can be computed. / Series: Research Report Series / Department of Statistics and Mathematics