On the Usage of Global Document Occurrences in Peer-to-Peer Information Systems

Papapetrou, Odysseas; Michel, Sebastian; Bender, Matthias; Weikum, Gerhard

doi:10.1007/11575771_21

Cited by 4 publications

(3 citation statements)

References 31 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their system relies on the use of an underlying structured P2P network. A similar approach is described in [21], which is quite different from our setup that assumes an unstructured P2P architecture.…”

Section: P2p Document Retrievalmentioning

confidence: 93%

A hybrid approach for estimating document frequencies in unstructured P2P networks

Neumayer

Doulkeridis

Nørvåg

2011

Information Systems

View full text Add to dashboard Cite

“…Their system relies on the use of an underlying structured P2P network. A similar approach is described in [88], which is quite different from our setup that assumes an unstructured P2P architecture.…”

Section: P2p Document Retrievalmentioning

confidence: 99%

Semantic and distributed entity search in the web of data

Neumayer

2012

SIGIR Forum

View full text Add to dashboard Cite

Both the growth and ubiquitious character of the Internet have had a profound effect on how we access and consume ata and information. More recently, the Semantic Web, an extension of the current Web has come increasingly relevant due to its widespread adoption.The Web of Data (WoD) is an extension of the current web, where not only documents are interlinked by means of hyperlinks but also data in terms of predicates. Specifically, it describes objects, entities or "things" in terms of their attributes and their relationships, using RDF data (and often is used equivalently to Linked Data). Given its growth, there is a strong need for making this wealth of knowledge accessible by keyword search (the de-facto standard paradigm for accessing information online).The overall goal of this thesis is to provide new techniques for accessing this data, i.e., to leverage its full potential to end users. We therefore address the following four main issues: a) how can the Web of Data be searched by means of keyword search?, b) what sets apart search in the WoD from traditional web search?, c) how can these elements be used in a theoretically sound and effective way?, and d) How can the techniques be adapted to a distributed environment?To this end, we develop techniques for effectively searching WoD sources. We build upon and formalise existing entity modelling approaches within a generative language modelling framework, and compare them experimentally using standard test collections. We show that these models outperform the current state-of-the-art in terms of retrieval effectiveness, however, this is done at the cost of abandoning a large part of the semantics behind the data. We propose a novel entity model capable of preserving the semantics associated with entities, without sacrificing retrieval effectiveness. We further show how these approaches can be applied in the distributed context, both with low (federated search) and high numbers (Peerto-peer or P2P) of independent repositories, collections, or nodes.The main contributions are as follows:• We develop a hybrid approach to search in the Web of Data, using elements from traditional information retrieval and structured retrieval alike.• We formalise our approaches in a language model setting.• Our extensions are successfully evaluated with respect to their applicability in different distributed environments such as federated search and P2P.• We discuss and analyse based on our empirical evaluation and provide insights into the entity search problem. Preface

show abstract

“…The local results obtained from there are merged by the query initiator. The MINERVA Project has been presented in [26], while related papers are [27,24,23,25,28,47,141,120,119].…”

Section: Dhts Related Workmentioning

confidence: 99%

A Content–Addressable Network for Similarity Search in Metric Spaces

Falchi

Gennaro

Zezula

Databases, Information Systems, and Peer-to-Peer Computing

View full text Add to dashboard Cite

Because of the ongoing digital data explosion, more advanced search paradigms than the traditional exact match are needed for contentbased retrieval in huge and ever growing collections of data produced in application areas such as multimedia, molecular biology, marketing, computer-aided design and purchasing assistance. As the variety of data types is fast going towards creating a database utilized by people, the computer systems must be able to model human fundamental reasoning paradigms, which are naturally based on similarity. The ability to perceive similarities is crucial for recognition, classification, and learning, and it plays an important role in scientific discovery and creativity. Recently, the mathematical notion of metric space has become a useful abstraction of similarity and many similarity search indexes have been developed. In this thesis, we accept the metric space similarity paradigm and concentrate on the scalability issues. By exploiting computer networks and applying the Peer-to-Peer communication paradigms, we build a structured network of computers able to process similarity queries in parallel. Since no centralized entities are used, such architectures are fully scalable. Specifically, we propose a Peerto-Peer system for similarity search in metric spaces called Metric Content-Addressable Network (MCAN) which is an extension of the well known Content-Addressable Network (CAN) used for hash lookup. A prototype implementation of MCAN was tested on real-life datasets of image features, protein symbols, and text-observed results are reported. We also compared the performance of MCAN with three other, recently proposed, distributed data structures for similarity search in metric spaces. It is a great honor and privilege for me to have an international joint supervision of my Ph.D. dissertation. I want to thank the University of Pisa and the Masaryk University, Brno for their agreement regarding this joint supervision. I am grateful to my supervisors Lanfranco Lopriore, Fausto Rabitti and Pavel Zezula for their guidance and encouragement. Since I was not just a Ph.D. student at the University of Pisa but also at the Masaryk University, I had the opportunity to work with several researchers in Brno, especially Michal Batko, David Novak and Vlastislav Dohnal. The discussions we had and the work we did together were fundamental for the completion of this thesis. This thesis would not have been possible without the substantial help from Claudio Gennaro and without the discussions I had with Giuseppe Amato and Pasquale Savino. I also thank all the other people at the Networked Multimedia Information Systems laboratory of the Institute of Information Science and Technologies, especially Fausto Rabitti who is the head of the laboratory and his predecessor Costantino Thanos. I would also like to thank Cosimo Antonio Prete and Sandro Bartolini for teaching me the basics of research during my master thesis. Finally, I thank my mother and father for supporting me during my studies.

show abstract

On the Usage of Global Document Occurrences in Peer-to-Peer Information Systems

Cited by 4 publications

References 31 publications

A hybrid approach for estimating document frequencies in unstructured P2P networks

Semantic and distributed entity search in the web of data

A Content–Addressable Network for Similarity Search in Metric Spaces

Contact Info

Product

Resources

About