Transaction management on collaborative application services

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.Includes bibliographical references (leaves 86-87).by Koon-Po Paul Wong.M.Eng

Toward a Framework for Understanding Object-Oriented Development Practices

This paper describes specific object-oriented system development cases that resulted from interviews with system developers in a variety of large Midwestern firms. Four object-oriented projects are described, reflecting thediversity of the types of systems and types of technology involved. A few typical issues are discussed. This is the first phase of a research project that seeks to understand issues related to object-oriented development. Additional research is planned todefine and measure key development issues, and this will require developing a instrument based on the findings from these cases

Model-driven generative programming for BIS mobile applications

The burst on the availability of smart phones based on the Android platform calls for cost-effective techniques to generate mobile apps for general purpose, distributed business information systems (BIS). To mitigate this problem our research aims at applying model-driven techniques to automatically generate usable prototypes with a sound, maintainable, architecture. Following three base principles: model-based generation, separation of concerns, paradigm seamlessness, we try to answer the main guiding question – how to reduce development time and cost by transforming a given domain model into an Android application? To answer this question we propose to develop an application that follows a generative approach for mobile BIS apps that will mitigate the identified problems. Its input is a platform independent model (PIM), with business rules specified in OCL (Object Constraint Language). We adopted the Design Science Research methodology, that helps gaining problem understanding, identifying systemically appropriate solutions, and in effectively evaluating new and innovative solutions. To better evaluate our solution, besides resorting to third party tools to test specific components integration, we demonstrated its usage and evaluated how well it mitigates a subset of the identified problems in an observational study (we presented our generated apps to an outside audience in a controlled environment to study our model-based centered and, general apps understandability) and communicated its effectiveness to researchers and practitioners.O grande surto de disponibilidade de dispositivos móveis para a plataforma Android requer, técnicas generativas de desenvolvimento de aplicações para sistemas comuns e/ou distribuídos de informação empresariais/negócio, que otimizem a relação custo-benefício. Para mitigar este problema, esta investigação visa aplicar técnicas orientadas a modelos para, automaticamente, gerar protótipos funcionais de aplicações com uma arquitetura robusta e fácil de manter. Seguindo para tal três princípios base: geração baseada no modelo, separação de aspetos, desenvolvimento sem soturas (sem mudança de paradigma), tentamos dar resposta à pergunta orientadora – como reduzir o tempo e custo de desenvolvimento de uma aplicação Android por transformação de um dado modelo de domínio? De modo a responder a esta questão nós propomos desenvolver uma aplicação que segue uma abordagem generativa para aplicações de informação empresariais/negócio móveis de modo a mitigar os problemas identificados. Esta recebe modelos independentes de plataforma (PIM), com regras de negócio especificadas em OCL (Object Constraint Language). Seguimos a metodologia Design Science Research que ajuda a identificar e perceber o problema, a identificar sistematicamente soluções apropriadas aos problemas e a avaliar mais eficientemente soluções novas e inovadoras. Para melhor avaliar a nossa solução, apesar de recorrermos a ferramentas de terceiros para testar a integração de componentes específicos, também demonstramos a sua utilização, através de estudos experimentais (em um ambiente controlado, apresentamos as nossas aplicações geradas a uma audiência externa que nos permitiu estudar a compreensibilidade baseada e centrada em modelos e, de um modo geral, das aplicações) avaliamos o quanto esta mitiga um subconjunto de problemas identificados e comunicamos a sua eficácia para investigadores e profissionais

Using Actors to Build a Parallel DBMS

In this paper, we present the design and the architecture of a parallel main memory database management system. We focus on concurrency control scheme and recovery. Our prototype is based on the concept of “database actors”, an object-oriented data model well suited for parallelmanipulations. The storage sub system is built upon distributed Ram-files using SDDS (Scalable Distributed Data Structures) techniques. A nested transaction model is proposed and used to handle concurrency access and recovery. We have also proposed novel approach, based on wait-die, to implement a distributed deadlock prevention technique for our model of nested transactions

Modeling views in the layered view model for XML using UML

In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources. Conversely, since the introduction of Extensible Markup Language (XML), it is fast emerging as the dominant standard for storing, describing, and interchanging data among various web and heterogeneous data sources. In combination with XML Schema, XML provides rich facilities for defining and constraining user-defined data semantics and properties, a feature that is unique to XML. In this context, it is interesting to investigate traditional database features, such as view models and view design techniques for XML. However, traditional view formalisms are strongly coupled to the data language and its syntax, thus it proves to be a difficult task to support views in the case of semi-structured data models. Therefore, in this paper we propose a Layered View Model (LVM) for XML with conceptual and schemata extensions. Here our work is three-fold; first we propose an approach to separate the implementation and conceptual aspects of the views that provides a clear separation of concerns, thus, allowing analysis and design of views to be separated from their implementation. Secondly, we define representations to express and construct these views at the conceptual level. Thirdly, we define a view transformation methodology for XML views in the LVM, which carries out automated transformation to a view schema and a view query expression in an appropriate query language. Also, to validate and apply the LVM concepts, methods and transformations developed, we propose a view-driven application development framework with the flexibility to develop web and database applications for XML, at varying levels of abstraction

Object-Oriented Development "The New Design Problem"

New techniques often involve innovative approaches and looking at the problem they address from a different perspective: OO will be of heavy impact of the software construction. The technological shift from classical development and structured methods to evolutionary development and object-oriented methods is certainly not easy. We must given it the time and the means in terms of structures, training, staff, and support for all to come effective. C,S has joined several R&D projects to test if and how Object Orientation can be applied to its software. We share here our considerations on OO development and the understanding obtained through practical experiences within the CMS object oriented activities and the RD41 (Moose) project

Object-Oriented Software Representation of Polymer Materials Information in Engineering Design

The software application POISE, Polymer Objects in a Smalltalk™ Environment, integrates knowledge representation, user interfaces, and data management; a system of tools for the materials domain expert involved in design. Engineering design solutions initially build from generalisations. POISE represents multiple levels of generalisations from classifications of polymer information. The class-instance paradigm classifies software objects. An object’s behaviour is an exclusive function of its class. Polymer’s behaviours are a function of multiple orthogonal factors, like chemistry and processing, therefore multiple orthogonal classes must represent polymers. Taxonomy only represents one of these factors. The Enhancer mechanism resolves this conflict between classification and representation. Polymer classification is not well established, with new materials evolving. The software compensates by evolving the classification schema. Guided with a specialised interface tool, the domain expert updates the schema by adding new polymer families and re-classifying existing classes. Through analysing the generalisations in the classification, the domain expert can develop an appropriate classification. This analysis relies on the engineering properties differentiating the principal material qualities. Standard properties do not distinguish specific structural differences in polymer materials, necessitating new properties. Material properties distinguish materials in the domain whereas the classes describe the properties of polymer objects. Domain experts add new properties to the polymer classes to distinguish polymer objects. Properties are independent objects that partially describe the class template; Partial Template Objects. Persistence of personal design information and management of shared data requires dichotomous database management. Shared data requires multi-user access, and consequently transaction management. Transaction management in object-oriented systems often holds resources for a long duration. Transaction declaration hinders transparent access to storage, and corrupts the representation. For single-user design information, transactions are implicit with access. Database proxies provide transparent per-object transaction management to persistent design information. The WorkBase is an object-storage utility that utilises Enhancers as proxies

Computer Science's Digest Volume 2

This series of textbooks was created for the students of the Systems Engineering Program at the University of Nariño. They have been intentionally written in English to promote reading in a foreign language. The textbooks are a collection of reflections and workshops on specific situations in the field of computer science, based on the authors’ experiences. The main purpose of these textbooks is essentially academic. The way in which the reflections and workshops were constructed follows a didactic structure, to facilitate teaching and learning, making use of English as a second language. This book covers Internet and Multimedia Technology, System Analysis and Design, and Software Engineerin