Michele Angelaccio

QBD*: a graphical query language with recursion

A system to query databases using diagrams as a standard user interface is proposed. The system, called Query by Diagram* (QBD*), makes use of a conceptual data model, a query language on this model, and a graphical user interface. The conceptual model is the entity-relationship model. The query language, whose expressive power allows recursive queries, supports visual interaction. The main characteristics of the interface are ease of use and the availability of a rich set of primitives for schema selection and query formulation. The expressive power of QBD* and G/sup +/, which are the only languages allowing recursive queries to be expressed graphically are compared. >

WORKPAD: an Adaptive Peer-to-Peer Software Infrastructure for Supporting Collaborative Work of Human Operators in Emergency/Disaster Scenarios

The system presented in the paper is the main result of an on-going European research project WORKPAD (IST- 2005-5-034749) that aims at building and developing an innovative software infrastructure (software,models, services, etc.) for supporting collaborative work of human operators in emergency/disaster scenarios. In such scenarios, different teams, belonging to different organizations, need to collaborate each other to reach a common goal; each team member is equipped with handheld devices (PDAs) and communication technologies, and should carry on specific tasks. In such a way we can consider the whole team as carrying on a process (macro-process), and the different teams (of the different organizations) collaborate through the interleaving of all the different processes. The idea is to investigate a 2-level framework for such scenarios: a back-end peer-to-peer community, providing advanced services requiring high computational power, data-knowledge-content integration, and a set of front-end peer-to-peer communities, that provide services to human workers, mainly by adaptively enacting processes on mobile ad-hoc networks.

Fundamental graphical primitives for visual query languages

Abstract The need of a friendly man-machine interaction is becoming crucial for a large variety of applications. In order to reach such a friendliness a new class of languages has been proposed (Visual Languages), based on the extensive use of graphical and iconic mechanisms. We are interested in a particular subclass of Visual Languages, called Visual Query Languages (VQLs), devoted to the extraction of information from databases. VQLs are mainly based on the idea of applying new interaction mechanisms, based on the “direct manipulation” paradigm, on visually represented databases. Various VQLs have been proposed, but only a few of them are provided with a formal definition and, also when such a formal definition exists, it does not give the semantics of the graphical operations performed by the user. In this paper we aim to provide such a semantics by proposing a graphical data model, the graph model, in which the visual representation is part of the model itself and a minimal set of Graphical Primitives, in terms of which general query operations may be visually expressed. Moreover, we show that: 1. (a) such a model may be used as a general visual representation for the most common data models; 2. (b)the Graphical Primitives have the same expressive power as well-known query languages; 3. (c) the graph model and the Graphical Primitives may be used as basic constituents of more complex existing visual representations and visual query languages, thus giving them a semantics independent from the underlying data model.

Query by diagram: A fully visual query system

The need of a friendly man-machine interaction is becoming crucial for a large variety of applications, in particular, those requiring frequent extraction of information from the database. Experience suggests that traditional query languages are not friendly enough for the causal user: s/he is requested to formulate queries in a textural language, without any iconic or spatial clues to help the querying process. A new generation of languages (visual languages) has been recently investigated, that attempts to make extensive use of the persons instincts and senses. In this paper we propose a fully visual system, called Query by Diagram^* (QBD^*), which is based on a conceptual data model, a query language defined on this model and a graphical user interface. The main characteristics of the interface are the ease of use, and the availability of a rich set of primitives for both schema selection and query formulation. Unlike many present proposals of graphical query systems, graphical operations are formally defined from both a syntactic and a semantic point of view.

Smart and Mobile Access to Cultural Heritage Resources: A Case Study on Ancient Italian Renaissance Villas

Cultural Heritage Areas together Context-Aware Systems present a great opportunity where the Ambient Intelligence (AmI) paradigm can be successfully applied. This paper deals with the design of an AmI-based Information Systems, based on NFC (Near Field Communication) technology, developed to access Cultural Heritage Areas of particular interest, in which different objects of artistic interest can be interfaced in a proper virtual way without affecting the historical environment. The application of non-invasive technology NFC improves the context-awareness of the implemented system and allows users to receive customized information in a transparent way, through the most suitable device, allowing a realistic experience. The proposed AmI-based Information System is particular related to mobile and safe cultural access in the context of Villa Mondragone, an ancient Renaissance Villa. We outline a real system, called SMART VILLA, based on a set of mobile applets, each interfaced with a NFC based subsystem, related to particular sites (SMART BIBLIO for ancient books, SMART ROOM for particular rooms and SMART GARDEN for surrounding historical gardens).

A model transformation framework to boost productivity and creativity in collaborative working environments

Collaborative working environments consist of a network of spatially dispersed actors (either humans or not) that play different roles and cooperate to achieve a common goal. Notwithstanding the ever increasing potential of innovative software and network technologies, collaborative working environments still require advanced solutions to effectively managing their inherent complexity, thereby boosting productivity and creativity. Essential components of innovative service-based collaborative working environments are collaboration-aware services that embed the required point-to-point or multi-point interaction patterns to support the flexible orchestration of distributed and concurrent activities. This paper introduces an approach that attempts to overcome the above mentioned drawbacks of current collaborative working environments by exploiting the precepts recently introduced by model-driven development and MDA (model driven architecture). The proposed approach is guided by a model transformation framework that makes use of the set of MDA-related standards (MOF, QVT and XMI) to obtain a high degree of automation, so that interoperable model transformation services can be implemented in a timely and efficient way. At the end, the single tool usually operated by a given worker can be considered as a virtual collaborative platform for creating and automatically transforming models of different types and at various levels of abstraction.

A Model-Driven Framework for Managing the QoS of Collaborative P2P Service-Based Applications

Distributed and collaborative applications are rapidly converging towards the adoption of a computing paradigm based on service-oriented architectures, according to which an application results from the composition of a set of services in execution on networked server hosts. In this context, a major challenge for collaborative businesses and application service providers is to provide services with high levels of QoS to geographically dislocated consumers. In order to enable better QoS, service providers may employ overlay networks to bring applications closer to their consumers, overcoming slow backbone paths, network congestions and physical latencies. This paper introduces a model-driven QoS management framework that provides both a standard (UML-based) notation to describe QoS-aware collaborative P2P service-based applications and a method for adaptive QoS management based on the automated building of performance models

A visualisation system for Web local search

World Wide Web visualisation systems are widely used for browsing or viewing search engine results. In the case of a local Web search tool, however, the browsing paradigm is combined with a searching paradigm, thus requiring dynamic visualisation methods. We describe an example of a visualisation system that is an extension of a common JavaScript script that is used as a Web site map. It is interfaced with a Java-based local search tool named VSEARCH. Our system provides an easy-to-integrate mechanism to implement information visualisation techniques like node colouring.

QBD: a fully visual system for E-R oriented databases

The need of a friendly man-machine interaction is becoming crucial for a large variety of applications, in particular, those requiring frequent extraction of information from the database. Experience suggests that traditional query languages are not friendly enough for the casual user: she/he is requested to formulate queries in a textual language, without any iconic or spatial clues to help the querying process. A new generation of languages (visual languages) has been recently investigated, that attempts to make extensive use of the persons instincts and senses. The authors propose a fully visual system, called Query by Diagram (QBD), which is based on a conceptual data model, a query language defined on this model and a graphical user interface. The main characteristics of the interface are the ease of use, and the availability of a rich set of primitives for both schema selection and query formulation. Unlike many present proposals of graphical query systems, graphical operations are formally defined from both a syntactic and a semantic point of view.<<ETX>>

Local searching the Internet

Local searching tools search Web pages that are on or close to a Web site in order to answer specific queries. A Web query taxonomy based on WebSQL can help to enhance local searching techniques.