Paolo Manghi

XPeer: a self-organizing XML P2P database system

This paper describes XPeer , a zero-administration system for sharing and querying XML data The system allows users to share XML data without significant human intervention, and to pose XQuery FLWR queries against them The proposed system can be used in any application field, being a general purpose XML p2p DBMS, even though its main application is the management of resource descriptions in GRID environments.

Data journals: A survey

Data occupy a key role in our information society. However, although the amount of published data continues to grow and terms such as data deluge and big data today characterize numerous (research) initiatives, much work is still needed in the direction of publishing data in order to make them effectively discoverable, available, and reusable by others. Several barriers hinder data publishing, from lack of attribution and rewards, vague citation practices, and quality issues to a rather general lack of a data‐sharing culture. Lately, data journals have overcome some of these barriers. In this study of more than 100 currently existing data journals, we describe the approaches they promote for data set description, availability, citation, quality, and open access. We close by identifying ways to expand and strengthen the data journals approach as a means to promote data set access and exploitation.

A vision towards Scientific Communication Infrastructures

The two pillars of the modern scientific communication are Data Centers and Research Digital Libraries (RDLs), whose technologies and admin staff support researchers at storing, curating, sharing, and discovering the data and the publications they produce. Being realized to maintain and give access to the results of complementary phases of the scientific research process, such systems are poorly integrated with one another and generally do not rely on the strengths of the other. Today, such a gap hampers achieving the objectives of the modern scientific communication, that is, publishing, interlinking, and discovery of all outcomes of the research process, from the experimental and observational datasets to the final paper. In this work, we envision that instrumental to bridge the gap is the construction of “Scientific Communication Infrastructures”. The main goal of these infrastructures is to facilitate interoperability between Data Centers and RDLs and to provide services that simplify the implementation of the large variety of modern scientific communication patterns.

Static analysis for path correctness of XML queries

A part of a query that will never contribute data to the query answer should be regarded as an error. This principle has been recently accepted into mainstream XML query languages, but was still waiting for a complete treatment. We provide here a precise definition for this class of errors, and define a type system that is sound and complete, in its search for such errors, for a core language, under mild restrictions on the use of recursion in type definitions. In the process, we describe a dichotomy among existential and universal type systems, which is essential to understand some specific features of our type system.

Types for path correctness of XML queries

If a subexpression in a query will never contribute data to the query answer, this should be regarded as an error. This principle has been recently accepted into mainstream XML query languages, but was still waiting for a complete treatment. We provide here a precise definition for this class of errors, and define a type system that is sound and complete, in its search for such errors, for a core language, under mild restrictions on the use of recursion in type definitions. In the process, we describe a dichotomy among existential and universal type systems, which is useful to understand some unusual features of our type system.

Hybrid applications over XML: integrating the procedural and declarative approaches

We discuss the design of a quasi-statically typed language for XML in which data may be associated with different structures and different algebras in different scopes, whilst preserving identity. In declarative scopes, data are trees and may be queried with the full flexibility associated with XML query algebras. In procedural scopes, data have more conventional structures, such as records and sets, and can be manipulated with the constructs normally found in mainstream languages.For its original form of structural polymorphism, the language offers integrated support for the development of hybrid applications over XML, where data change form to reflect programming expectations and enable their enforcement.

The D-NET software toolkit

Purpose – The purpose of this paper is to present the architectural principles and the services of the D-NET software toolkit. D-NET is a framework where designers and developers find the tools for constructing and operating aggregative infrastructures (systems for aggregating data sources with heterogeneous data models and technologies) in a cost-effective way. Designers and developers can select from a variety of D-NET data management services, can configure them to handle data according to given data models, and can construct autonomic workflows to obtain personalized aggregative infrastructures. Design/methodology/approach – The paper provides a definition of aggregative infrastructures, sketching architecture, and components, as inspired by real-case examples. It then describes the limits of current solutions, which find their lacks in the realization and maintenance costs of such complex software. Finally, it proposes D-NET as an optimal solution for designers and developers willing to realize aggre...

An Extensible Virtual Digital Libraries Generator

In this paper we describe the design and implementation of the VDL Generator, a tool to simplify and automatise the Digital Library development process. In particular, we discuss how our approach to the realisation of this tool simplifies the task of implementing, extending and modifying such a fundamental component. This tool models its issue as a generic search problem that can easily be adapted to different application scenarios. In particular, to guarantee its extensibility we carefully identify, isolate and organise the VDL Generator constituents, i.e. (i) the set of logical componentsthat can be used when designing a Digital Library, (ii) the set of physical componentsthat by implementing the logical components contribute to implement the Digital Library and (iii) the search strategyexploited to accomplish the generation task. Furthermore, we report on the experiences matured in implementing and exploiting such an innovative service in the context of the Diligent EU funded project and discuss future plans for its consolidation.

An Approach to high-level language bindings to XML

Abstract Values of existing typed programming languages are increasingly generated and manipulated outside the language jurisdiction. Instead, they often occur as fragments of XML documents, where they are uniformly interpreted as labelled trees in spite of their domain-specific semantics. In particular, the values are divorced from the high-level type with which they are conveniently, safely, and efficiently manipulated within the language. We propose language-specific mechanisms which extract language values from arbitrary XML documents and inject them in the language. In particular, we provide a general framework for the formal interpretation of extraction mechanisms and then instantiate it to the definition of a mechanism for a sample language core L . We prove that such mechanism can be built by giving a sound and complete algorithm that implements it. The values, types, and type semantics of L are sufficiently general to show that extraction mechanisms can be defined for many existing typed languages, including object-oriented languages. In fact, extraction mechanisms for a large class of existing languages can be directly derived from L s. As a proof of this, we introduce the SNAQue prototype system, which transforms XML fragments into CORBA objects and exposes them across the ORB framework to any CORBA-compliant language.

PACE: A General-Purpose Tool for Authority Control

Curating the records of an authority file is an activity as important as committing for many organizations, which have to rely on experts equipped with so-called authority control tools, capable of automatically supporting complex disambiguation workflows through user-friendly interfaces. This paper presents PACE, an open source authority control tool which offers user interfaces for (i) customizing the structure (ontology) of authority files, (ii) tune-up probabilistic disambiguation of authority files through a set of similarity functions for detecting record candidates for duplication and overload (iii) curate such authority files by applying record merges and splitting actions, and (iv) expose authority files to third-party consumers in several ways. PACE’s back-end is based on Cassandra’s “NOSQL”technology to offer (i) read-write performances that scale up linearly with the number of records and (ii) parallel and efficient (MapReduce-based) record sorting and matching algorithms.