物件導向軟體之架構(Object-Oriented Software Construction)探討

Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

An overview of AspectJ

Data Nodes, Edges Display Interactive Display Visual Analogues VisualItems in ItemRegistry User Figure 6.3: The Information Visualisation Reference Model, adapted from Heer et al.[57] 6.2 State of the Art 93 a visual analytics issue that should be better tackled by all the visualisation communities. Blending different kinds of visualisations in the same application is becoming Blending different kinds of visualisations is currently difficult more frequent. Scientific visualisation and geographic visualisation need information visualisation because they manage multi-valued data with complex topologies that can be visualised using their canonical geometry. In addition, they can also be explored with more abstract visual representations to avoid geometric artefacts. For example, census data can be visualised as a coloured map but also as a multi-dimensional dataset where the longitude and latitude are two attributes among others. Clustering this data by some similarity measure will then reveal places that can be far away in space but behave similarly in term of other attributes (e.g., level of education, level of income, size of houses etc.), similarity that would not be visible on a map. On top of these visualisation systems, a user interface allows control of the overall application. User interfaces are well understood but they can be very different in styles. 3D systems use specific types of interfaces that are very different to traditional desktop interfaces. Moreover, information visualisation systems tend to deeply embed the interaction with the visualisation, offering special kinds of controls either directly inside the visualisations (e.g., range sliders on the axes of parallel coordinates) or around it but with special kinds of widgets (e.g., range sliders for performing range-queries). Interoperability can thus be described at several levels. At the data management level, at the architecture model level and at the interface level. 6.2.2 Data Management All visual analytics applications start with data that can be either statically collected or dynamically produced. Depending on the nature of the data, visual analytics applications have used various ways of managing their storage. In order of sophistication, they are: Flat files using ad-hoc formats, Structured file formats such as XML, Specialised NoSQL systems, including Cloud Storage, Standard or extended transactional databases (SQL), Workflow or dataflow systems integrating storage, distribution and data processing. We will now consider these data storage methods, paying particular attention to Data Management for visual analytics can rely on different levels of sophistication the levels of service required by visual analytics, such as: Persistence (they all provide it by definition), Typing, Distribution, Atomic transactions, Notification, Interactive performance, Computation.

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Mastering the information age : solving problems with visual analytics

In this paper, we review current requirements engineering (RE) research and identify future research directions suggested by emerging software needs. First, we overview the state of the art in RE research. The research is considered with respect to technologies developed to address specific requirements tasks, such as elicitation, modeling, and analysis. Such a review enables us to identify mature areas of research, as well as areas that warrant further investigation. Next, we review several strategies for performing and extending RE research results, to help delineate the scope of future research directions. Finally, we highlight what we consider to be the "hot" current and future research topics, which aim to address RE needs for emerging systems of the future.

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Research Directions in Requirements Engineering

Traceability--the ability to follow the life of software artifacts--is a topic of great interest to software developers in general, and to requirements engineers and model-driven developers in particular. This article aims to bring those stakeholders together by providing an overview of the current state of traceability research and practice in both areas. As part of an extensive literature survey, we identify commonalities and differences in these areas and uncover several unresolved challenges which affect both domains. A good common foundation for further advances regarding these challenges appears to be a combination of the formal basis and the automated recording opportunities of MDD on the one hand, and the more holistic view of traceability in the requirements engineering domain on the other hand.

https://link.springer.com/content/pdf/10.1007%2Fs10270-009-0145-0.pdf

A survey of traceability in requirements engineering and model-driven development

This paper presents an aspect-oriented approach to dynamic adaptation. A systematic process for defining where, when, and how an adaptation is to be incorporated into an application is presented. Specifically, the paper presents a two-phase approach to dynamic adaptation, where the first phase prepares a non-adaptive program for adaptation, and the second phase implements the adaptation at run time. This approach is illustrated with a distributed conferencing application.

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An aspect-oriented approach to dynamic adaptation

de facto standard for object-oriented modelling. Currently, UML comprises several different notations with no formal semantics attached to the individual diagrams or their integration, thus preventing rigorous analysis of the diagrams. Previously, we developed a formalisation framework that attaches formal semantics to a subset of UML diagrams used to model embedded systems. This paper describes automated structural and behavioural analyses applicable to UML diagrams using our formalisation framework. In addition to intra- and inter-diagram consistency checks, we discuss how simulation and model checking can be used in tandem for behavioural analysis of the UML diagrams. Our tools also visually interpret the analysis results in terms of the original UML diagrams, thereby facilitating their correction and refinement. We illustrate these capabilities through the modelling and analysis of UML diagrams for an automotive industrial case study.

Automatically Detecting and Visualising Errors in UML Diagrams

The field of program comprehension is characterized by both the continuing development of new tools and techniques and the adaptation of existing techniques to address program comprehension needs for new software development and maintenance scenarios. The adoption of these techniques and tools in industry requires proper experimentation to assess the advantages and disadvantages of each technique or tool and to let the practitioners choose the most suitable approach for a specific problem. The objective of this working session is to encourage researchers and practitioners working in the area of program comprehension to join forces to design and carry out studies related to program comprehension, including observational studies, controlled experiments, case studies, surveys, and contests, and to develop standards for describing and carrying out such studies in a way that facilitates replication of data and aggregation of the results of related studies.

Designing your Next Empirical Study on Program Comprehension

Programs that use multithreaded concurrency are known to be difficult to design. Moreover, research in computer-science education suggests that concurrency and synchronization concepts are generally difficult to master. It stands to reason that comprehension tasks may be more complex for programs that employ concurrency than for sequential programs. We believe that external representations, specifically refinements to some of the popular UML modeling notations, should aid students in mastering fundamental concurrency/synchronization concepts and should enable practitioners to better comprehend the dynamically evolving nature of the these programs. In this paper, we present our synchronization adorned UML (saUML) sequence diagram notation that highlights aspects of thread interactions and describe an empirical study of whether these diagrams, as opposed to purely textual representations, help students to better understand concurrent executions and concurrency concepts, as measured by their ability to answer questions about a particular execution of a multi-threaded system. A statistically significant benefit was found from the study.

Empirical Evaluation of a UML Sequence Diagram with Adornments to Support Understanding of Thread Interactions

Amalia is a generator framework for constructing analyzers for operationally defined formal notations. These generated analyzers are components that are designed for customization and integration into a larger environment. The customizability, and efficiency of Amalia analyzers owe to a computational structure called an inference graph. This paper describes this structure, how inference graphs enable Amalia to generate analyzers for operational specifications, and how we build in assurance. On another level, this paper illustrates how to balance the need for assurance, which typically implies a formal proof obligation, against other design concerns, whose solutions leverage design techniques that are not (yet) accompanied by mature proof methods. We require Amalia-generated designs to be transparent with respect to the formal semantic models upon which they are based. Inference graphs are complex structures that incorporate many design optimizations. While not formally verifiable, their fidelity with respect to a formal operational semantics can be discharged by inspection.

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R. E. K. Stirewalt

Papers

An aspect-oriented approach to dynamic adaptation

Automatically Detecting and Visualising Errors in UML Diagrams

Designing your Next Empirical Study on Program Comprehension

Empirical Evaluation of a UML Sequence Diagram with Adornments to Support Understanding of Thread Interactions

Inference graphs: a computational structure supporting generation of customizable and correct analysis components