Pattern Reification as the Basis for Description-Driven Systems

One of the main factors driving object-oriented software development for information systems is the requirement for systems to be tolerant to change. To address this issue in designing systems, this paper proposes a pattern-based, object-oriented, description-driven system (DDS) architecture as an extension to the standard UML four-layer meta-model. A DDS architecture is proposed in which aspects of both static and dynamic systems behavior can be captured via descriptive models and meta-models. The proposed architecture embodies four main elements - firstly, the adoption of a multi-layered meta-modeling architecture and reflective meta-level architecture, secondly the identification of four data modeling relationships that can be made explicit such that they can be modified dynamically, thirdly the identification of five design patterns which have emerged from practice and have proved essential in providing reusable building blocks for data management, and fourthly the encoding of the structural properties of the five design patterns by means of one fundamental pattern, the Graph pattern. A practical example of this philosophy, the CRISTAL project, is used to demonstrate the use of description-driven data objects to handle system evolution.Comment: 20 pages, 10 figure

Be My Guest: Normalizing and Compiling Programs using a Host Language

In programming language research, normalization is a process of fundamental importance to the theory of computing and reasoning about programs.In practice, on the other hand, compilation is a process that transforms programs in a language to machine code, and thus makes the programminglanguage a usable one. In this thesis, we investigate means of normalizing and compiling programs in a language using another language as the "host".Leveraging a host to work with programs of a "guest" language enables reuse of the host\u27s features that would otherwise be strenuous to develop.The specific tools of interest are Normalization by Evaluation and Embedded Domain-Specific Languages, both of which rely on a host language for their purposes. These tools are applied to solve problems in three different domains: to show that exponentials (or closures) can be eliminated from a categorical combinatory calculus, to propose a new proof technique based on normalization for showing noninterference, and to enable the programming of resource-constrained IoT devices from Haskell

Towards Language-Oriented Modeling

In this habilitation à diriger des recherches (HDR), I review a decade of research work in the fields of Model-Driven Engineering (MDE) and Software Language Engineering (SLE). I propose contributions to support a language-oriented modeling, with the particular focus on enabling early validation & verification (V&V) of software-intensive systems. I first present foundational concepts and engineering facilities which help to capture the core domain knowledge into the various heterogeneous concerns of DSMLs (aka. metamodeling in the small), with a particular focus on executable DSMLs to automate the development of dynamic V&V tools. Then, I propose structural and behavioral DSML interfaces, and associated composition operators to reuse and integrate multiple DSMLs (aka. metamodeling in the large).In these research activities I explore various breakthroughs in terms of modularity and reusability of DSMLs. I also propose an original approach which bridges the gap between the concurrency theory and the algorithm theory, to integrate a formal concurrency model into the execution semantics of DSMLs. All the contributions have been implemented in software platforms — the language workbench Melange and the GEMOC studio – and experienced in real-world case studies to assess their validity. In this context, I also founded the GEMOC initiative, an attempt to federate the community on the grand challenge of the globalization of modeling languages

Metaphor, Objects, and Commodities

This article is a contribution to a symposium that focuses on the ideas of Margaret Jane Radin as a point of departure, and particularly on her analyses of propertization and commodification. While Radin focuses on the harms associated with commodification of the person, relying on Hegel's idea of alienation, we argue that objectification, and in particular objectification of various features of the digital environment, may have important system benefits. We present an extended critique of Radin's analysis, basing the critique in part on Gadamer's argument that meaning and application are interrelated and that meaning changes with application. Central to this interplay is the speculative form of analysis that seeks to fix meaning, contrasted with metaphorical thought that seeks to undermine some fixed meanings and create new meanings through interpretation. The result is that speculative and metaphorical forms are conjoined in an interactive process through which new adaptations emerge. Taking this critique an additional step, we use examples from contemporary intellectual property law discourse to demonstrate how an interactive approach, grounded in metaphor, can yield important insights

Understanding the Emergent Structure of Competency Centers in Post-implementation Enterprise Systems

Part 3: Structures and NetworksInternational audiencePrior research provides conflicting insights about the link between investment in enterprise systems and firm value and in the ES governance mechanisms. The literature generally suggests that management should cultivate its technical and organizational expertise to derive value from currently deployed Enterprise Systems (ES) [8]. In the realm of practice, ERP vendors and configuration/integration partners strongly recommend the creation of an organizational structure to govern the ERP implementation and post-implementation process to improve project success and extract greater value from the ES investment. The ES literature, while unclear on the formation, and functioning of ES governance units, suggests the need for formal and fixed governance structures. This research utilizes Deleuze’s assemblage theory and emergence theory to explain the genesis and evolution of the governing ‘structure’ known as the Competency Center (CC). Our results illustrate the business needs driving the structuring processes behind the CC, are also those that lead to unintended and destabilizing outcomes. Whether the CC ‘assemblage’ survives to provide value depends on how the emergent issues are handled and how the assemblages are “positioned”. This research suggests effective ES governance is not derived from a prescribed step-wise process yielding formal structures, but rather form an organic process of assemblage

Inherently flexible software

Software evolution is an important and expensive consequence of software. As Lehman's First Law of Program Evolution states, software must be changed to satisfy new user requirements or become progressively less useful to the stakeholders of the software. Software evolution is difficult for a multitude of different reasons, most notably because of an inherent lack of evolveability of software, design decisions and existing requirements which are difficult to change and conflicts between new requirements and existing assumptions and requirements. Software engineering has traditionally focussed on improvements in software development techniques, with little conscious regard for their effects on software evolution. The thesis emphasises design for change, a philosophy that stems from ideas in preventive maintenance and places the ease of software evolution more at the centre of the design of software systems than it is at present. The approach involves exploring issues of evolveability, such as adaptability, flexibility and extensibility with respect to existing software languages, models and architectures. A software model, SEvEn, is proposed which improves on the evolveability of these existing software models by improving on their adaptability, flexibility and extensibility, and provides a way to determine the ripple effects of changes by providing a reflective model of a software system. The main conclusion is that, whilst software evolveability can be improved, complete adaptability, flexibility and extensibility of a software system is not possible, hi addition, ripple effects can't be completely eradicated because assumptions will always persist in a software system and new requirements may conflict with existing requirements. However, the proposed reflective model of software (which consists of a set of software entities, or abstractions, with the characteristic of increased evolveability) provides trace-ability of ripple effects because it explicitly models the dependencies that exist between software entities, determines how software entities can change, ascertains the adaptability of software entities to changes in other software entities on which they depend and determines how changes to software entities affect those software entities that depend on them

Map4Scrutiny – a linked open data solution for politicians interest registers

Dissertação de mestrado em Sistemas de InformaçãoO trabalho desenvolvido no âmbito desta dissertação descreve o processo de recolha, uniformização e transformação de dados abertos em formato de texto e tabelas (CSV) para dados abertos ligados (Linked Open Data). Especificamente, dados sobre os registos de interesses dos deputados à assembleia da república portuguesa e contratação pública, ligados pelas organizações que são mencionadas em ambos. O estado da arte inclui uma análise de fundo aos conceitos de corrupção, transparência, dados abertos, e dados abertos ligados, tal como a projetos de dados abertos e dados abertos ligados relevantes. A seleção dos dados a utilizar, com respeito aos tópicos de conjuntos de dados relevantes e ao interesse público, o desenho da solução proposta e a seleção de ferramentas, métodos e processos, seguiu a proposta de três ciclos de Hevner para uma abordagem ao desenho de investigação na ciência. O processo de implementação é iniciado com a recolha de dados das fontes utilizando bibliotecas Python para web Scraping e a transformação dos mesmos em tabelas (CSV). Estes dados são depois limpos e uniformizados com auxílio do OpenRefine. Esta ferramenta é também usada para mapear os dados da tabela para triples que são exportados em ficheiros Turtle. Este mapeamento foi previamente desenhado num perfil de aplicação que serviu de base para a criação das formas dos dados (ShExC) usadas para conduzir o processo de validação nos ficheiros Turtle. Esta validação assegura que os ficheiros gerados pelo OpenRefine são conformes com o perfil de aplicação. Para descrever adequadamente os dados foram usados vocabulários já existentes complementados, quando necessário, com a criação de novas classes, propriedades e valores. Este processo está também descrito e os vocabulários estão disponíveis para consulta e reutilização. Por fim, foram feitas consultas modelo em SPARQL para ilustrar a diferença entre os dados originais e o conjunto de dados transformado. O objetivo deste trabalho é contribuir para as áreas de dados abertos ligados e dados abertos para a transparência e escrutínio público. Os contributos principais para o primeiro são um novo esquema de dados e a descrição de todos os passos do processo de transformação. Para o segundo o contributo que se destaca é mais uma implementação que demonstra o potencial do escrutínio de dados no aumento da transparência através da comparação entra as consultas possíveis aos conjuntos de dados originais e ao resultante da solução proposta. O processo de implementação está documentado abaixo e os ficheiros resultantes disponibilizados para consulta.The work developed in the scope of this dissertation describes the process of sourcing, uniformizing, and transforming text and tabular (CSV) open data to linked open data. More exactly, data on Portuguese parliamentarians’ interest registers and public procurement, linked by the organisations mentioned in both. The state of the art presented includes a background analysis on the concepts of corruption, transparency, open data, and linked open data and an analysis of relevant open data and linked open data projects. The research was conducted using Hevner’s three-cycle design science research approach which led to the definition of the data scope concerning relevant dataset topics and the public’s interest, the design of the proposed solution, and the selected tools, methods, and processes. The implementation process starts with Scraping the data from the sources with the aid of python libraries and generating tabular (CSV) outputs. These are cleaned and uniformized in OpenRefine. OpenRefine is also the tool used to map the data on the tables into triples and generate outputs in Turtle. The map was designed in an application profile that also served as a base for writing the shapes (in ShExC) and conducting validation on the exported Turtle files. This validation ensures that the data is conformant with the application profile. To successfully describe the data in triples, on top of the external vocabularies used, new classes, properties and values had to be created. This process is also thoroughly described, and the outputs are open to access and reuse. Finally, sample SPARQL queries were made to showcase the difference between the sourced data and the resulting dataset. The goal is to contribute to the field of linked open data and open data for transparency and public scrutiny. The main contributions to the first are a new data scheme and the description of every step in the transformation process, while to the latter the contribution is a further implementation showcasing the scrutiny potential of data in improving transparency by comparing the querying possibilities of the final dataset with the originals. Every step taken is documented below and the resulting outputs of the different stages are available for consultation