Gerald Reif

A Web-based peer-to-peer architecture for collaborative nomadic working

With the recent advances in mobile computing, distributed organizations are facing a growing need for advanced information and communication technologies (ICT) that support mobile working. The ability to use information effectively anywhere and anytime has become a key business success factor. Although many computer supported collaborative work (CSCW) systems have been introduced to date, technologies and architectures that support the collaboration of nomadic workers on a wide range of mobile devices, notebooks and personal computers is still a challenge. The MObile Teamwork Infrastructure for Organizations Networking (MOTION) project is aiming to design a highly flexible, open and scalable ICT architecture for mobile collaboration. We present the mobile collaboration requirements of two MOTION industry case studies, and highlight the advantages of a Web-based peer-to-peer architecture for nomadic working.

A comparison of RDB-to-RDF mapping languages

Mapping Relational Databases (RDB) to RDF is an active field of research. The majority of data on the current Web is stored in RDBs. Therefore, bridging the conceptual gap between the relational model and RDF is needed to make the data available on the Semantic Web. In addition, recent research has shown that Semantic Web technologies are useful beyond the Web, especially if data from different sources has to be exchanged or integrated. Many mapping languages and approaches were explored leading to the ongoing standardization effort of the World Wide Web Consortium (W3C) carried out in the RDB2RDF Working Group (WG). The goal and contribution of this paper is to provide a feature-based comparison of the state-of-the-art RDB-to-RDF mapping languages. It should act as a guide in selecting a RDB-to-RDF mapping language for a given application scenario and its requirements w.r.t. mapping features. Our comparison framework is based on use cases and requirements for mapping RDBs to RDF as identified by the RDB2RDF WG. We apply this comparison framework to the state-of-the-art RDB-to-RDF mapping languages and report the findings in this paper. As a result, our classification proposes four categories of mapping languages: direct mapping, read-only general-purpose mapping, read-write general-purpose mapping, and special-purpose mapping. We further provide recommendations for selecting a mapping language.

Supporting developers with natural language queries

The feature list of modern IDEs is steadily growing and mastering these tools becomes more and more demanding, especially for novice programmers. Despite their remarkable capabilities, IDEs often still cannot directly answer the questions that arise during program comprehension tasks. Instead developers have to map their questions to multiple concrete queries that can be answered only by combining several tools and examining the output of each of them manually to distill an appropriate answer. Existing approaches have in common that they are either limited to a set of predefined, hardcoded questions, or that they require to learn a specific query language only suitable for that limited purpose. We present a framework to query for information about a software system using guided-input natural language resembling plain English. For that, we model data extracted by classical software analysis tools with an OWL ontology and use knowledge processing technologies from the Semantic Web to query it. We use a case study to demonstrate how our framework can be used to answer queries about static source code information for program comprehension purposes.

A service architecture for mobile teamwork

Mobile teamwork has become an emerging requirement in the daily business of large enterprises. Employees collaborate across locations and need support while they are on the move. Business documents (artifacts) and expertise need to be shared independent of the actual location or connectivity (e.g., access through a mobile phone, laptop, Personal Digital Assistant, etc.) of employees. Although many collaboration tools and systems exist, most do not deal with new requirements such as locating artifacts and experts through distributed searches, advanced information subscription and notification, and mobile information sharing and access. The MOTION service architecture that we have developed supports mobile teamwork by taking into account the different connectivity modes of users, provides access support for various devices such as laptop computers and mobile phones, and uses XML meta-data and the XML Query Language (XQL) for distributed searches and subscriptions. In this paper, we describe the architecture and the components of our generic MOTION service platform for building collaborative applications. The MOTION Teamwork Services Components are currently being evaluated in two industry case-studies.

Updating relational data via SPARQL/update

Relational Databases are used in most current enterprise environments to store and manage data. The semantics of the data is not explicitly encoded in the relational model, but implicitly on the application level. Ontologies and Semantic Web technologies provide explicit semantics that allows data to be shared and reused across application, enterprise, and community boundaries. Converting all relational data to RDF is often not feasible, therefore we adopt an ontology-based access to relational databases. While existing approaches focus on read-only access, we present our approach OntoAccess that adds ontology-based write access to relational data. OntoAccess consists of the updateaware RDB to RDF mapping language R3M and algorithms for translating SPARQL/Update operations to SQL. This paper presents the mapping language, the translation algorithms, and a prototype implementation of OntoAccess.

SEON: a pyramid of ontologies for software evolution and its applications

AbstractThe Semantic Web provides a standardized, well-established framework to define and work with ontologies. It is especially apt for machine processing. However, researchers in the field of software evolution have not really taken advantage of that so far. In this paper, we address the potential of representing software evolution knowledge with ontologies and Semantic Web technology, such as Linked Data and automated reasoning. We present Seon, a pyramid of ontologies for software evolution, which describes stakeholders, their activities, artifacts they create, and the relations among all of them. We show the use of evolution-specific ontologies for establishing a shared taxonomy of software analysis services, for defining extensible meta-models, for explicitly describing relationships among artifacts, and for linking data such as code structures, issues (change requests), bugs, and basically any changes made to a system over time. For validation, we discuss three different approaches, which are backed by Seon and enable semantically enriched software evolution analysis. These techniques have been fully implemented as tools and cover software analysis with web services, a natural language query interface for developers, and large-scale software visualization.

Evaluation of a publish/subscribe system for collaborative and mobile working

The MObile Teamwork Infrastructure for Organizations Networking (MOTION) service platform that we have designed and implemented addresses an emerging requirement in the daily business of large, distributed enterprises: support for mobile teamwork. Employees are often on the move and use a wide range of computing devices such as WAP phones, PDAs, notebooks and desktop computers. The service architecture that we have developed supports mobile teamwork by providing multi-device service access, XML meta data for information sharing and locating, and the XML Query Language (XQL) for distributed searches and publish/subscribe. We present the solution that we adopted in our prototype, analyze the shortcomings of this approach and based on our evaluation experiences, list the requirements for a publish-subscribe middleware for collaborative mobile working.

Fostering synergies: how semantic web technology could influence software repositories

The state-of-the-art in mining software repositories stores software artifacts from various sources into monolithic relational databases. This puts a lot of querying power in the hands of the software miners, however it comes at the cost of enclosing the data and hamper cross-application reuse. In this paper we discuss four problem scenarios to illustrate that Semantic Web technology is able to overcome these limitations. However, it requires that the software engineering research community agrees on two prerequisites: (a) a common vocabulary to talk about software repositories -- an ontology; (b) a strategy for generating unique and stable references to all software artifacts inside such a repository -- a Universal Resource Identifier (URI).

MOTION: a peer-to-peer platform for mobile teamwork support

Large, global enterprises are increasingly faced with the problem of supporting employees that are on the move. Employees need to share business documents, locate expertise and knowledge through distributed searches, access effective subscription/notification mechanisms, and they need any time, anywhere access to the companys information resources. We address these problems and requirements in the MObile Teamwork Infrastructure for Organizations Networking (MOTION) project and aim to create an advanced information and communication technology (ICT) infrastructure for mobile teamwork. We give a brief description of the MOTION peer-to-peer platform for mobile teamwork.

TWSAPI: a generic teamwork services application programming interface

One of the problems faced by large, global organizations and enterprises is to effectively enable their employees to collaborate across locations. People need collaborative work support while they are on the move and have to share business documents and know-how. Although much work has been done in the area of computer supported collaborative work (CSCW) to date, supporting mobility is only recently receiving attention. Hence, most of the existing approaches do not deal with emerging mobile teamwork requirements such as locating business documents and expertise through distributed searches, advanced subscription and notification, community building, and mobile information sharing and access. Furthermore, existing applications and approaches are usually difficult to customize to business-specific processes and requirements. The Mobile Teamwork Infrastructure for Organizations Networking (MOTION) system addresses these requirements and provides a generic teamwork services application programming interface (API), TWSAPI, that can be used to build organization-specific collaborative applications. In this paper we give an overview of the MOTION TWSAPI and illustrate its usage in building an application that provides document review support.