Join Point Designation Diagrams: Eine grafische Darstellungsweise für den Entwurf von Join Point Selektionen in der aspektorientierten Softwareentwicklung

Sharing knowledge about program specifications is a crucial task in collaborative software development. Developers need to be able to properly assess the objectives of the program specification in order to adequately deploy or evolve a piece of program. The specification of join point selections (also known as "pointcuts") in Aspect-Oriented Software Development (AOSD) is a piece of a program which frequently tends to grow quite complex, in particular if the join point selections involve selection constraints on the dynamic execution history of the program. In that case, readers of the pointcut specification frequently find themselves confronted with considerable comprehension problems because they need to inspect and realize an intricate and fragmented program specification in order to reconstruct the true objectives of the join point selection. This thesis presents Join Point Designation Diagrams (JPDDs) as a possible solution to the problem. JPDDs are a visual notation that provides an extensive set of join point selection means which are consolidated from a variety of contemporary aspect-oriented programming languages. JPDDs are capable of highlighting different join point selection constraints depending on the conceptual view on program execution which underlies the join point selection. With the help of these means, JPDDs are capable of representing complex join point selections on the dynamic execution of a program in a succinct and concise manner. JPDDs may be used by software developers of different aspect-oriented programming languages to represent their join point selections for the sake of an improved comprehensibility of the join point selections and – thus – for the sake of an easier communication between software developers. This thesis gives empirical evidence that JPDDs indeed facilitate the comprehensibility of join point selections. To do so, it conducts a controlled experiment which compares JPDDs to equivalent pointcut implementations in an aspect-oriented programming language. The experiment shows that JPDDs have a clear benefit over their codified counterparts in most of the case, while only in few cases no such benefit could be measured.Die Kommunikation und der Wissensaustausch zwischen Softwareentwicklern über Programmspezifikationen ist eine essentielle Notwendigkeit in großen Softwareprojekten. Softwareentwickler müssen den Sinn und Zweck eines (Teil)Programms richtig erfassen, bevor sie in der Lage sind, das (Teil)Programm richtig einzubinden bzw. weiterzuentwickeln. Join Point Selektionen in der aspektorientierten Softwareentwicklung (auch "Pointcuts" genannt) sind ein Beispiel für Programmspezifikationen, die schnell komplex werden – insbesondere dann, wenn sie Selektionsbedingungen enthalten, die sich auf die Laufzeitvergangenheit eines Programms beziehen. Die Spezifikationen solcher Join Point Selektionen sind oft schwer zu verstehen, da Softwareentwickler eine Vielzahl kleiner Spezifikationsfragmente und ihre Abhängigkeiten analysieren müssen, bevor sie den Sinn und Zweck einer Join Point Selektion erfassen können. Diese Dissertation präsentiert Join Point Designation Diagrams (JPDDs) als eine Lösung für das Problem. JPDDs sind eine grafische Notation, die eine Vielzahl von Selektionstechniken aus aktuellen aspektorientierten Programmiersprachen vereinigt. JPDDs ermöglichen es, unter Berücksichtigung gängiger konzeptioneller Sichten auf die Programmausführung relevante Selektionsbedingungen besonders hervorzuheben. Dabei stellen JPDDs Bedingungen, die sich auf die Laufzeitvergangenheit eines Programms beziehen, unzersplittert dar. JPDDs können von Softwareentwicklern unterschiedlicher Programmiersprachen benutzt werden, um ihre Join Point Selektionen zu spezifizieren und so das Verständnis der Join Point Selektionen – und damit die Kommunikation und den Wissensaustausch zwischen Softwareentwicklern – zu vereinfachen. Diese Dissertation weist mit Hilfe eines kontrollierten empirischen Experiments nach, dass JPDDs tatsächlich in der Lage sind, das Verständnis von Join Point Selektionen zu vereinfachen. Dazu werden JPDDs mit äquivalenten Pointcut-Spezifikationen in einer aspektorientierten Programmiersprache verglichen. Das Experiment zeigt, dass JPDDs in der Mehrzahl der Fälle vorteilhaft sind. Nur in wenigen Ausnahmen konnte kein Vorteil im Vergleich zu der aspektorientierten Programmiersprache beobachtet werden

Modelling of Aspects using Aspect-Oriented Design Language

The Aspect-composition is a vital step in aspect modelling. Aspects are composed with each other and with base constructs through pointcuts defined in the aspects. Design languages address this composition by providing composition techniques and directives. However, most of the contemporary design languages lack support for inter-aspect and inner-aspect compositions. Another problem is resolving aspect interference which arises as a result of a composition. Although some techniques have been proposed to overcome aspect interference at the implementation level, the problem needs attention at the modelling level. The eradication of interference and conflicts related to aspect composition at the modelling stage could ensure better implementation and fewer conflicts. This paper provides a composition strategy equipped with new design notations and diagrams to provide support for aspect compositions, as well as inneraspect compositions. The paper also provides a technique to prioritize aspect execution at the modelling stage to reduce aspect interference and aspect conflicts

From Personalization to Adaptivity: Creating Immersive Visits through Interactive Digital Storytelling at the Acropolis Museum

Storytelling has recently become a popular way to guide museum visitors, replacing traditional exhibit-centric descriptions by story-centric cohesive narrations with references to the exhibits and multimedia content. This work presents the fundamental elements of the CHESS project approach, the goal of which is to provide adaptive, personalized, interactive storytelling for museum visits. We shortly present the CHESS project and its background, we detail the proposed storytelling and user models, we describe the provided functionality and we outline the main tools and mechanisms employed. Finally, we present the preliminary results of a recent evaluation study that are informing several directions for future work

Aiding compliance governance in service-based business processes

Assessing whether a company's business practices conform to laws and regulations and follow standards and SLAs, i.e., compliance management, is a complex and costly task. Few software tools aiding compliance management exist; yet, they typically do not address the needs of who is actually in charge of assessing and understanding compliance. We advocate the use of a compliance governance dashboard and suitable root cause analysis techniques that are specifically tailored to the needs of compliance experts and auditors. The design and implementation of these instruments are challenging for at least three reasons: (1) it is fundamental to identify the right level of abstraction for the information to be shown; (2) it is not trivial to visualize different analysis perspectives; and (3) it is difficult to manage and analyze the large amount of involved concepts, instruments, and data. This chapter shows how to address these issues, which concepts and models underlie the problem, and, eventually, how IT can effectively support compliance analysis in Service-Oriented Architectures (SOAs). © 2012, IGI Global

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

Managing Utility Properties: Fire Risk Awareness and Mitigation

Southern California Edison is concerned with fire and the danger it poses to its equipment and employees, and their current strategies are becoming outdated. To help solve this problem, this project developed a web application that allows the user to identify the areas that might be influenced by a fire instance, retrieve information about assets in the danger zone, and display the assets and their risk levels. With this tool, the emergency response teams can more accurately decide what areas are most in need of assistance in a timely fashion. By increasing their efficiency of disaster management, lives and money can be saved

Improving the Usability of OCL as an Ad-hoc Model Querying Language

Abstract. The OCL is often perceived as difficult to learn and use. In previous research, we have defined experimental query languages exhibiting higher levels of usability than OCL. However, none of these alternatives can rival OCL in terms of adoption and support. In an attempt to leverage the lessons learned from our research and make it accessible to the OCL community, we propose the OCL Query API (OQAPI), a library of query-predicates to improve the user-friendliness of OCL for ad-hoc querying. The usability of OQAPI is studied using controlled experiments. We find considerable evidence to support our claim that OQAPI facilitates user querying using OCL.

High Level Efficiency in Database Languages

The subject of this Ph.D. thesis is the design and implementation of database languages. The thesis consists of five articles:  [1] Joan F. Boyar and Kim S. Larsen. Efficient Rebalancing of Chromatic Search Trees. In O. Nurmi and E. Ukkonen, eds., LNCS 621: Algorithm Theory -- SWAT'92 , pp. 151-164. Springer-Verlag, 1992. [2] Kim S. Larsen. On Aggregation and Computation on Domain Values. PB-414, Computer Science Department, Aarhus University, 1992. [3] Kim S. Larsen. Strategies for Expression Evaluation Using Sort-Merge Algorithms. PB-415, Computer Science Department, Aarhus University, 1992. [4] Kim S. Larsen and Michael I. Schwartzbach. Injectivity of Unary Queries With Computation on Domain Values. Computer Science Department, Aarhus University, 1992. Revised version of PB-311. [5] Kim S. Larsen, Michael I. Schwartzbach and Erik M. Schmidt. A New Formalism for Relational Algebra. IPL , 41(3):163-168, 1992. and this survey paper. In [5], a new query language design is proposed. The expressive power of the language is determined in [2] and all reasonable extensions are considered. In [3, 4], we focus on the optimization issue of avoiding unnecessary sorting of relations. The results in these papers are directly applicable to any algebra-based query language. In addition to the query language part, a database system also has to offer update facilities. The theory of standard tuple based updates is quite well developed in the sequential case. In [1], we discuss a new concurrent implementation of balanced search trees for that purpose.This survey paper describes the results of the papers which form the thesis, and relates these results to each other and to the area in a broader sense than is customary in the introductions of individual papers. The paper is intended to be read in combination with the papers on which it is based