Strategic Directions in Object-Oriented Programming

This paper has provided an overview of the field of object-oriented programming. After presenting a historical perspective and some major achievements in the field, four research directions were introduced: technologies integration, software components, distributed programming, and new paradigms. In general there is a need to continue research in traditional areas:\ud (1) as computer systems become more and more complex, there is a need to further develop the work on architecture and design; \ud (2) to support the development of complex systems, there is a need for better languages, environments, and tools; \ud (3) foundations in the form of the conceptual framework and other theories must be extended to enhance the means for modeling and formal analysis, as well as for understanding future computer systems

An extensible view system for supporting the integration and interoperation of heterogeneous, autonomous, and distributed database management systems

In this thesis the problem of integrating heterogeneous, autonomous and distributed database management systems (DBMSs) is addressed. To provide a solution, we have developed an approach, a design method, and a view system. Our approach is based on the invention of the abstract view constructs that have uniform and stable representations for supporting semantic relativism and distributed abstraction modeling. Our design method applies object-oriented techniques and software engineering concepts to manage the system complexity. Our view system has been constructed upon established experience with the development of large-scale distributed systems in a distributed object infrastructure provided by the Common Object Request Broker Architecture (CORBA). The scope of our research identifies the goals of Project Zeus in which we have created the Zeus View Mechanism ( ZVM) as the theoretical foundation of our approach. The notion of frameworks has been introduced as part of our design methodology to promote code/design reuse and enhance the portability/extensibility of the architectural design. A multidatabase system, the Zeus Multidatabase System ( ZMS), has provided a test bed for our concept. Project Zeus has exciting prospects. The foundation established in this research has created new directions in multidatabase research and will have a significant impact on future integration and interoperation technologies

Extracting Object Oriented Software Architecture from C++ Source Code

Software architecture strongly influences the ability to satisfy quality attributes such as modifiability, performance, and security. It is important to be able to analyse and extract information about that architecture. However, architectural documentation frequently does not exist, and when it does, it is often out of sync with the implemented system. In addition, it is not all that software development begins with a clean slate; systems are almost always constrained by the existing legacy code. As a consequence, there is a need to extract information from existing system implementations and reason architecturally about this information. This research presents a reverse engineering tool VOO++ that will read an Object- Oriented C++ source code using UML notation in order to visualise its Class structure and the various relationships that may exist including, inheritance, aggregation, and dependency relationships based on the modified Cohen-Sutherland clipping algorithm. The idea of clipping is reversed, instead of clipping inside the rectangle, the clipping is done out side the rectangle in terms of four directions (left, right, top, and bottom) and two points represent the centre point for each rectangle. An Object-Oriented approach is used to design and implement the tool. Reverse engineering, design pattern, and graphics are the underlying techniques supplied. VOO++ aids an analyst in extracting, manipulating and interpreting the Object-Oriented static model information. By assisting in the reconstruction of static architectures from extracted information, VOO++ helps an analyst to redocument and understand architectures and discover the relationship between "as-implemented" and "asdesigned" architectures

Component Based Systems Development Adoption and Diffusion

Component Based Development (CBD) has caught the attention of academics and practitioners alike. Building upon sound Object-Oriented principles, CDB has a strong conceptual foundation as well as extensive practical orientation and application. CBD approaches promise the potential to deliver quality systems in a short period of time with opportunities for component reuse to further reduce cost that seems especially appropriate for the myriad of e-business systems that are a focal point of many organizations’ contemporary systems development portfolios. Indeed, numerous commercial organizations are supplying components that can be relatively easily integrated to create cost-effective systems. Interestingly, however, CBD is currently not applied extensively. The prospective reasons are many. Management is currently ill-informed and not committed to the CBD approach as they often lack knowledge of the benefits of adopting CBD. Further, many system developers, system analysts and programmers are not aware of CBD issues and opportunities. Possible reasons could be that they received their software education a long time ago (e.g. five or ten years ago or more), and are only familiar with traditional approaches. There is also considerable confusion with regard to component granularity and CBD focus. To some, the focus is on creating the components while to others, the focus is on creating systems by integrating components. A question exists as to the role of education and research given this situation. Numerous opportunities exist for academics to play a leading role in creating awareness and removing uncertainties in exploring CBD concepts and application. However, little attention is currently being given to CBD, especially in teaching. Like IS professionals, many educators are hesitant to change from traditional development perspectives currently being taught as they face faculty development challenges. By in large, few have had experience in this area and easily fall back to what they learned historically. Further, there is a dearth of textbooks and educational material available to assist academic in the teaching process. Research seems to be fragmented and lacking coherency in focus. Research, teaching and practice all seem to be going in different directions

Exploring Maintainability Assurance Research for Service- and Microservice-Based Systems: Directions and Differences

To ensure sustainable software maintenance and evolution, a diverse set of activities and concepts like metrics, change impact analysis, or antipattern detection can be used. Special maintainability assurance techniques have been proposed for service- and microservice-based systems, but it is difficult to get a comprehensive overview of this publication landscape. We therefore conducted a systematic literature review (SLR) to collect and categorize maintainability assurance approaches for service-oriented architecture (SOA) and microservices. Our search strategy led to the selection of 223 primary studies from 2007 to 2018 which we categorized with a threefold taxonomy: a) architectural (SOA, microservices, both), b) methodical (method or contribution of the study), and c) thematic (maintainability assurance subfield). We discuss the distribution among these categories and present different research directions as well as exemplary studies per thematic category. The primary finding of our SLR is that, while very few approaches have been suggested for microservices so far (24 of 223, ?11%), we identified several thematic categories where existing SOA techniques could be adapted for the maintainability assurance of microservices

Reusability in software engineering

This paper surveys recent work concerning reusability in software engineering. The current directions in software reusability are discussed, and the two major approaches of reusable building blocks and reusable patterns studied. An extensive bibliography, parts of which are annotated, is included

Neural Dynamics of Motion Perception: Direction Fields, Apertures, and Resonant Grouping

A neural network model of global motion segmentation by visual cortex is described. Called the Motion Boundary Contour System (BCS), the model clarifies how ambiguous local movements on a complex moving shape are actively reorganized into a coherent global motion signal. Unlike many previous researchers, we analyse how a coherent motion signal is imparted to all regions of a moving figure, not only to regions at which unambiguous motion signals exist. The model hereby suggests a solution to the global aperture problem. The Motion BCS describes how preprocessing of motion signals by a Motion Oriented Contrast Filter (MOC Filter) is joined to long-range cooperative grouping mechanisms in a Motion Cooperative-Competitive Loop (MOCC Loop) to control phenomena such as motion capture. The Motion BCS is computed in parallel with the Static BCS of Grossberg and Mingolla (1985a, 1985b, 1987). Homologous properties of the Motion BCS and the Static BCS, specialized to process movement directions and static orientations, respectively, support a unified explanation of many data about static form perception and motion form perception that have heretofore been unexplained or treated separately. Predictions about microscopic computational differences of the parallel cortical streams V1 --> MT and V1 --> V2 --> MT are made, notably the magnocellular thick stripe and parvocellular interstripe streams. It is shown how the Motion BCS can compute motion directions that may be synthesized from multiple orientations with opposite directions-of-contrast. Interactions of model simple cells, complex cells, hypercomplex cells, and bipole cells are described, with special emphasis given to new functional roles in direction disambiguation for endstopping at multiple processing stages and to the dynamic interplay of spatially short-range and long-range interactions.Air Force Office of Scientific Research (90-0175); Defense Advanced Research Projects Agency (90-0083); Office of Naval Research (N00014-91-J-4100

A review of information flow diagrammatic models for product-service systems

A product-service system (PSS) is a combination of products and services to create value for both customers and manufacturers. Modelling a PSS based on function orientation offers a useful way to distinguish system inputs and outputs with regards to how data are consumed and information is used, i.e. information flow. This article presents a review of diagrammatic information flow tools, which are designed to describe a system through its functions. The origin, concept and applications of these tools are investigated, followed by an analysis of information flow modelling with regards to key PSS properties. A case study of selection laser melting technology implemented as PSS will then be used to show the application of information flow modelling for PSS design. A discussion based on the usefulness of the tools in modelling the key elements of PSS and possible future research directions are also presented