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The MPEG Query Format: Unifying Access to Multimedia Retrieval Systems

The growth of multimedia is increasing the need for standards for accessing and searching distributed repositories. The moving picture experts group (MPEG) is developing the MPEG query format (MPQF) to standardize this interface as part of MPEG-7. The objective is to make multimedia access and search easier and interoperable across search engines and repositories. This article describes the MPQF and highlights some of the ways it goes beyond todays query languages by providing capabilities for multimedia query-by-example and spatiotemporal queries.

A vector space model for semantic similarity calculation and OWL ontology alignment

Ontology alignment (or matching) is the operation that takes two ontologies and produces a set of semantic correspondences (usually semantic similarities) between some elements of one of them and some elements of the other. A rigorous, efficient and scalable similarity measure is a pre-requisite of an ontology alignment process. This paper presents a semantic similarity measure based on a matrix represention of nodes from an RDF labelled directed graph. An entity is described with respect to how it relates to other entities using N-dimensional vectors, being N the number of selected external predicates. We adapt a known graph matching algorithm when applying this idea to the alignment of two ontologies. We have successfully tested the model with the public testcases of the Ontology Alignment Evaluation Initiative 2005.

The MPEG-7 query format: a new standard in progress for multimedia query by content

In recent years, the amount of Internet accessible digital audiovisual media files has vastly increased. Therefore the need to describe the media (by way of metadata) has also increased significantly. MPEG-7 (finalized in 2001) provides a comprehensive and rich metadata standard for the description of multimedia content. Unfortunately, a standardized query format does not exist for MPEG-7, or other multimedia metadata. Such a standard would provide for communications between querying clients and databases, supporting cross-modal and cross-media retrieval. The lSO/lEC SC29WG11 committee decided therefore to contribute to this application space by adding such functionality as a new part of the MPEG-7 series of standards. In response to a Call for Proposals, six proposals were submitted. This paper describes the strengths of each proposal as well as the resulting draft standard for the MPEG-7 query format.

Standardized interoperable image retrieval

Digital still images are generated, distributed and stored worldwide at an ever increasing rate. Yet, the large number of available metadata description formats prevents consistent and efficient access to image repositories. Standardized solutions for unifying the access and the retrieval of image repositories are therefore strongly needed. The ISO/IEC SC29 WG1 (more commonly known as JPEG) established the JPSearch project, which aims to standardize interfaces of an abstract image retrieval framework. In this context, the paper introduces our contribution consisting of a reference metadata model, which in combination with the JPEG query format improves interoperable image retrieval for users. Second, a transformation rule declaration language for query reformulation is presented, which contributes to interoperability at the repository side.

Architecture of a semantic XPath processor. application to digital rights management

This work describes a novel strategy for designing an XPath processor that acts over an RDF mapping of XML. We use a model-mapping approach to represent instances of XML and XML Schema in RDF. This representation retains the node order, in contrast with the usual structure-mapping approach. The processor can be fed with an unlimited set of XML schemas and/or RDFS/OWL ontologies. The queries are resolved taking into consideration the structural and semantic connections described in the schemas and ontologies. Such behavior, schema-awareness and semantic integration, can be useful for exploiting schema and ontology hierarchies in XPath queries. We test our approach in the Digital Rights Management (DRM) domain. We explore how the processor can be used in the two main rights expression languages (REL),: MPEG-21 REL and ODRL.

JPEG's JPSearch Standard: Harmonizing Image Management and Search

Triggered by the rise of social networks, community-based image sharing platforms are emerging at an increasing rate. Currently, almost every repository offers a different interaction interface and metadata description format. Unfortunately, this prevents unified and efficient access to these repositories. Consequently, data exchange between systems is often cumbersome. In this context, ISO/IEC JTC1 SC29 WG1 (more commonly known as JPEG) initiated the JPSearch framework standardization, which aims to foster the interaction with and among image repositories. The standard focuses on three main cornerstones supporting repository synchronization, search and access, and image collection creation and maintenance. This article discusses the main concepts, parts, and achievements of the JPSearch framework and demonstrates its use through a set of substantial case studies.

Managing intellectual property rights in the WWW: patterns and semantics

An architecture to manage digital rights, in this case intellectual property rights IPR, in the World Wide Web is being developed. It has as main features: semantics and complex systems analysis. Semantics allow establishing concepts meaning inside the architecture while statistics allow managing a huge amount of semantic information. In order to provide an efficient performance, some aspects have been enriched as digital rights information representation and database management. Semantic graphs encapsulate digital rights information and statistical analysis over the stored graphs in the semantic database allows extracting behavioral patterns. It is possible to distinguish four relevant phases: retrieval IPR from the World Wide Web performed by Web crawlers, IPR semantic representation, IPR statistical analysis in the semantic database and the last part concludes with action answers over DRM as negotiation aspects.

Dynamic Configuration of Partitioning in Spark Applications

Spark has become one of the main options for large-scale analytics running on top of shared-nothing clusters. This work aims to make a deep dive into the parallelism configuration and shed light on the behavior of parallel spark jobs. It is motivated by the fact that running a Spark application on all the available processors does not necessarily imply lower running time, while may entail waste of resources. We first propose analytical models for expressing the running time as a function of the number of machines employed. We then take another step, namely to present novel algorithms for configuring dynamic partitioning with a view to minimizing resource consumption without sacrificing running time beyond a user-defined limit. The problem we target is NP-hard. To tackle it, we propose a greedy approach after introducing the notions of dependency graphs and of the benefit from modifying the degree of partitioning at a stage; complementarily, we investigate a randomized approach. Our polynomial solutions are capable of judiciously use the resources that are potentially at user’s disposal and strike interesting trade-offs between running time and resource consumption. Their efficiency is thoroughly investigated through experiments based on real execution data.

Work in progress-improving feedback using an automatic assessment tool

Students of computer science freshman year usually develop assembler programs to learn processor architecture. Homework exercises are done on paper, while those in lab sessions are solved with the aid of programming tools. Students perceive theory and lab as different subjects, so they donpsilat use lab tools to test their theory solved problems. Moreover, during lab sessions, students often tend to ask for the teacherpsilas guide and advice instead of using the debugging tools because these are new and unfriendly for them, and do not offer a quick and clear feedback. In this paper we present an automatic and friendly assessment tool, SISA-EMU, with a novel feature: exercise driven feedback with teacherpsilas expertise. It provides correctness information and clues to help the students solve their most common mistakes for each individual problem (and not typical generic debug information) without the physical support of a teacher. SISA-EMU is currently in pre-deploy phase via a Moodle learning platform and we will have first evaluation results by the end of the current term.

The Anatomy of an Optical Biopsy Semantic Retrieval System

A case-based computer-aided diagnosis system assists physicians and other medical personnel in the interpretation of optical biopsies obtained through confocal laser endomicroscopy. Extraction in CLE images shows promising results on inferring semantic metadata from low-level features. In order to effectively ensure the interoperability with potential third-party applications, the system provides an interface compliant with the recent standards ISO/IEC 15938-12:2008 (MPEG Query Format) and ISO/IEC 24800 (JPEG Search).