Before-Commit Client State Management Services for AJAX Applications

Heavily script-based browser applications change the manner in which users interact with Web browsers. Instead of downloading a succession of HTML pages, users download a single application and use that application for a long period of time. The application is not a set of HTML pages, but rather a single page that can possible modify its own presentation based on data exchanged with a server. In such an environment, it is necessary to provide some means for the client to manage its own state. We describe the initial results of our work in providing client-side state management services for these script-based applications. We focus on browser-based services that can help the user before any data is committed on the server. Our services include state checkpointing, property binding, operation logging, operational replay, ATOM/RSS data updates, and application-controlled persistence

Initiatives and projects related to RD

This document is created as a part of the project “Repository for Research Data at IST Austria”. It summarises the actual initiatives, projects and standards related to the project. It supports the preparation of standards and specifications for the project, which should be considered and followed to ensure interoperability and visibility of the uploaded data

Modeling an engineering design application using extended object-oriented concepts

This paper presents an approach to extend object-oriented data models, in which versions of an object are allowed to appear at different levels of an inheritance hierarchy, in contrast to the known approaches where they are admitted only at one leveI. This approach allows the design and instantiation of objects to beco me very natural, starting with the design of an object in a class and refining it, adding properties to the subclasses. Versions of objects can be defined in a subclass, having ascendant versions/objects associated to the superclasses. The paper also discusses how the extended model can be used to model engineering applications, fulfilling their requirements. The application is the STAR frarnework, which implements an innovative and flexible data model that allows the user to define an object schema for each design object. Design alternatives and views can be created during the design process and are represented in the object schema. Versioning appears in the STAR model not only for the real design data, but also for alternatives and views in the object schema. This requirement is not naturally modeled by the existing version models in object-oriented databases

Versions and configurations in object-oriented database systems : a uniform treatment

Object-oriented database models usually allow versions only at the most specialized type/c1ass in an inheritance hierarchy. The possibility of having versions at different levels of abstraction provides a richer model and allows a more natural representation of the reality. The presence of objects and its corresponding sets of versions at different levels of a type/class hierarchy introduces the need for handling version mappings. Integrity constraints can be associated to these mappings, restricting the set of possible combinations of versions appearing at different levels of the hierarchy. Sets of versions associated with each levei of an object hierarchy often represent a very large set of possible configurations for that object, which is difficult to be handled directly by the user. In this context, adequate mechanisms are very important to define and build object configurations by means of selections applied to the set of all possible configurations, defined by the combinations of versions. This paper proposes an approach in which versions and configurations may appear at different levels of an inheritance hierarchy, and a uniform treatment is given to these two concepts

The Application of Object-Oriented Views to an Engineering Environment.

With the increasing popularity of object-oriented technology, object-oriented database systems are being used in design environments as central repositories. In this thesis, we investigate the role of versioning and the characteristics of design databases in design environments. In an effort to improve the configuration management scheme in a design environment, we also investigate the use of database views as a possible configuration tool. We propose a unified version management scheme that facilitates cooperative team work and show that the use of database views provides a powerful configuration management scheme for a design environment

Layering in Provenance Systems

Digital provenance describes the ancestry or history of a digital object. Most existing provenance systems, however, operate at only one level of abstraction: the sys- tem call layer, a workflow specification, or the high-level constructs of a particular application. The provenance collectable in each of these layers is different, and all of it can be important. Single-layer systems fail to account for the different levels of abstraction at which users need to reason about their data and processes. These systems cannot integrate data provenance across layers and cannot answer questions that require an integrated view of the provenance. We have designed a provenance collection structure facilitating the integration of provenance across multiple levels of abstraction, including a workflow engine, a web browser, and an initial runtime Python provenance tracking wrapper. We layer these components atop provenance-aware network storage (NFS) that builds upon a Provenance-Aware Storage System (PASS). We discuss the challenges of building systems that integrate provenance across multiple layers of abstraction, present how we augmented systems in each layer to integrate provenance, and present use cases that demonstrate how provenance spanning multiple layers provides functionality not available in existing systems. Our evaluation shows that the overheads imposed by layering provenance systems are reasonable.Engineering and Applied Science

FEMwiki: crowdsourcing semantic taxonomy and wiki input to domain experts while keeping editorial control: Mission Possible!

Highly specialized professional communities of practice (CoP) inevitably need to operate across geographically dispersed area - members frequently need to interact and share professional content. Crowdsourcing using wiki platforms provides a novel way for a professional community to share ideas and collaborate on content creation, curation, maintenance and sharing. This is the aim of the Field Epidemiological Manual wiki (FEMwiki) project enabling online collaborative content sharing and interaction for field epidemiologists around a growing training wiki resource. However, while user contributions are the driving force for content creation, any medical information resource needs to keep editorial control and quality assurance. This requirement is typically in conflict with community-driven Web 2.0 content creation. However, to maximize the opportunities for the network of epidemiologists actively editing the wiki content while keeping quality and editorial control, a novel structure was developed to encourage crowdsourcing – a support for dual versioning for each wiki page enabling maintenance of expertreviewed pages in parallel with user-updated versions, and a clear navigation between the related versions. Secondly, the training wiki content needs to be organized in a semantically-enhanced taxonomical navigation structure enabling domain experts to find information on a growing site easily. This also provides an ideal opportunity for crowdsourcing. We developed a user-editable collaborative interface crowdsourcing the taxonomy live maintenance to the community of field epidemiologists by embedding the taxonomy in a training wiki platform and generating the semantic navigation hierarchy on the fly. Launched in 2010, FEMwiki is a real world service supporting field epidemiologists in Europe and worldwide. The crowdsourcing success was evaluated by assessing the number and type of changes made by the professional network of epidemiologists over several months and demonstrated that crowdsourcing encourages user to edit existing and create new content and also leads to expansion of the domain taxonomy

Design Patterns for Description-Driven Systems

In data modelling, product information has most often been handled separately from process information. The integration of product and process models in a unified data model could provide the means by which information could be shared across an enterprise throughout the system lifecycle from design through to production. Recently attempts have been made to integrate these two separate views of systems through identifying common data models. This paper relates description-driven systems to multi-layer architectures and reveals where existing design patterns facilitate the integration of product and process models and where patterns are missing or where existing patterns require enrichment for this integration. It reports on the construction of a so-called description-driven system which integrates Product Data Management (PDM) and Workflow Management (WfM) data models through a common meta-model.Comment: 14 pages, 13 figures. Presented at the 3rd Enterprise Distributed Object Computing EDOC'99 conference. Mannheim, Germany. September 199