Carlos Bobed | University of Zaragoza (original) (raw)

Papers by Carlos Bobed

WEB 2013 Foreword The First International Conference on Building and Exploring Web Based Environm... more WEB 2013 Foreword The First International Conference on Building and Exploring Web Based Environments [WEB 2013], held between January 27th-February 1st, 2013 in Seville, Spain, was the inaugural conference on web-related theoretical and practical aspects, focusing on identifying challenges for building web-based useful services and applications, and for effectively extracting and integrating knowledge from the Web, enterprise data, and social media. The Web has changed the way we share knowledge, the way we design distributed services and applications, the way we access large volumes of data, and the way we position ourselves with our peers. Successful exploitation of web-based concepts by web communities lies on the integration of traditional data management techniques and semantic information into web-based frameworks and systems. We take here the opportunity to warmly thank all the members of the WEB 2013 Technical Program Committee, as well as the numerous reviewers. The creati...

Proceedings of the 10th International Conference on Web Information Systems and Technologies, 2014

Additional file 1: Appendix 1. Usability defects detected in OQT through the CW and the usability... more Additional file 1: Appendix 1. Usability defects detected in OQT through the CW and the usability testing sorted according to Scapin and Bastien usability category [34]. Slashes represent no change for a problem. Hyphens represent no detection of a problem. Appendix 2. Usability defects detected in Sparklis through the CW and the usability testing sorted according to Scapin and Bastien usability category [34]. Slashes represent no change for a problem. Hyphens represent no detection of a problem. Appendix 3. Usability defects detected by the CW and the usability testing for MCVM sorted according to Scapin and Bastien usability category [34]. Slashes represent no change for a problem. Hyphens represent no detection of a problem.

International Conference Knowledge Engineering and Knowledge Management, 2018

Pharmacovigilance is in charge of studying the adverse effects of pharmaceutical products. In thi... more Pharmacovigilance is in charge of studying the adverse effects of pharmaceutical products. In this field, pharmacovigilance specialists experience several difficulties when searching and exploring their patient data despite the existence of standardized terminologies (MedDRA). In this paper, we present our approach to enhance the way pharmacovigilance specialists perform search and exploration on their data. First, we have developed a knowledge graph that relies on the OntoADR ontology to semantically enrich the MedDRA terminology with SNOMED~CT concepts, and that includes anonymized patient data from FAERS. Second, we have chosen and extended a semantic search tool, Sparklis, according to the user requirements that we have identified in pharmacovigilance. We report the results of a usability evaluation that has been performed by human factors specialists to check the benefits of our proposal.

The results of an extractive automatic summarization task depends to a great extend on the nature... more The results of an extractive automatic summarization task depends to a great extend on the nature of the processed texts (e.g., news, medicine, or literature). In fact, general-purpose methods usually need to be adhoc modified to improve their performance when dealing with a particular application context. However, this customization requires a lot of effort from domain experts and application developers, which makes it not always possible nor appropriate. In this paper, we propose a multi-language approach to extractive summarization which adapts itself to different text domains in order to improve its performance. In a training step, our approach leverages the features of the text documents in order to classify them by using machine learning techniques. Then, once the text typology of each text is identified, it tunes the different parameters of the extraction mechanism solving an optimization problem for each of the text document classes. This classifier along with the learned op...

Information Sciences, 2020

Abstract Probabilistic Range Queries (PRQ) retrieve objects which, according to imprecise object ... more Abstract Probabilistic Range Queries (PRQ) retrieve objects which, according to imprecise object properties, are (with a given probability) inside a precise range. When the query range is based on some imprecise object properties, which makes the query range imprecise as well, then Uncertain Probabilistic Range Queries (UPRQ) arise. Unfortunately, in the literature UPRQs ranges are constrained to be balls, i.e., the range is defined by providing a certain radius around an imprecise object property. Moreover, another important issue is the efficiency of answering UPRQs due to the necessary numerical operations to calculate probabilities. In this work we give a novel definition for UPRQs with query ranges of any shape; in addition we prove that any UPRQ can be reduced to a PRQ. Concerning the efficiency of UPRQs, we adopt and improve the usual way to address this family of queries (i.e., constructing indexes to prune/validate which objects belong to the answer, avoiding unnecessary numerical calculations) presenting: (1) a method to improve the filtering capabilities of the indexes when dealing with uniform distributions over rectangles or balls; and (2) a new index (eUD-Index), which enhances the state of the art, for any type of probability distribution. Our experiments show the feasibility of the proposals.

Proceedings of the 8th International Conference on Agents and Artificial Intelligence, 2016

Web Semantics: Science, Services and Agents on the World Wide Web, 2015

The massive spread of mobile computing in our daily lives has attracted a huge community of mobil... more The massive spread of mobile computing in our daily lives has attracted a huge community of mobile application (apps) developers. These developers can take advantage of the benefits of semantic technologies (such as knowledge sharing and reusing, and knowledge decoupling) to enhance their applications. Moreover, the use of semantic reasoners would enable them to create more intelligent applications capable of discovering new knowledge, inferred from the available information.However, using semantic APIs and reasoners on current mobile devices is not a trivial task. In this paper, we show that the most popular current available Description Logics (DL) reasoners can be used on Android-based devices, and detail the efforts needed to port them to the Android platform. We also analyze the performance of these reasoners on current smartphones/tablets against more than 300 ontologies from the ORE?2013 ontology set, showing that, despite a notable difference with respect to desktop computers, their use is feasible.

Information Sciences, 2016

Abstract In the last years, users have become used to keyword-based search interfaces due to thei... more Abstract In the last years, users have become used to keyword-based search interfaces due to their ease of use. By matching input keywords against huge amounts of textual information and labeled multimedia files, current search engines satisfy most of users’ information needs. However, the principal problem of this kind of search is the semantic gap between the input and the real user need, as keywords are a simplification of the query intended by the user. Moreover, different users could use the same set of keywords to search different information; even the same user could do it at different times. The search system, before accessing any data, should discover first the intended semantics behind the user keywords, in order to return only data fulfilling such semantics. The use of formal query languages is not an option for non-expert users, so a semantic keyword-based search based on semantic interpretation of keyword queries could be the solution, i.e., a search that starts discovering the semantics intended for the input user keywords, and then only data relevant to that semantics are returned as answer. In this paper we present a system that performs semantic keyword interpretation on different data repositories. Our system (1) discovers the meaning of the input keywords by consulting a generic pool of ontologies and applying different disambiguation techniques; (2) once the meaning of each keyword has been established, the system combines them in a formal query that captures the semantics intended by the user, considering different formal query languages and possibilities that could arise, but avoiding inconsistent and semantically equivalent queries; and, finally, (3) after the user has validated the generated query that best fits her/his intended meaning, the system routes the query to the appropriate data repositories that will retrieve data according to the semantics of such a query. Experimental results show the semantic interpretation capabilities and the feasibility of our approach.

Semantic Web, 2015

In the last decade, we have witnessed the birth and spread of the Semantic Web and its associated... more In the last decade, we have witnessed the birth and spread of the Semantic Web and its associated semantic technologies. In this successful scenario, ontologies have played a crucial role. However, being knowledge representation frameworks as they are, the benefits of their use are beyond the WWW, but to many other different kind of systems, making it possible to design and develop smarter information systems which exploit the semantics of data.In this chapter, we present different semantic-based applications and projects that we have developed in the Distributed Information Systems (SID, in Spanish) research group of the University of Zaragoza. They address different application fields benefiting from semantic technologies to broaden their capabilities. In particular, we present our semantic systems for keyword-based search (QueryGen, Doctopush), information extraction (GENIE), fuzzy logic editing (Fuzzy OWL 2) and reasoning (fuzzy DL, DeLorean), and Location-Based Services managing (SHERLOCK).

Proceedings of the 2nd Workshop on Mobile Gaming, 2015

Mobile agents have been with us for a quite long time, showing their usefulness when it comes to ... more Mobile agents have been with us for a quite long time, showing their usefulness when it comes to developing distributed information systems. In particular, their dynamism, mobility, and adaptivity have been shown to be especially well-suited to deal with different problems that arise in mobile computing scenarios: the need for efficient access to heterogeneous and distributed data sources, dynamic load balancing, robustness in unstable connections and communication failures, etc. Indeed, developing mobile games using mobile agents technology would benefit from these characteristics in terms of infrastructures and on-demand deployment, but this is not the only benefit they could obtain from it. In this paper, we advocate using the paradigm of software mobile agents to enhance mobile games design. By exploiting their mobility, context adaptivity, autonomy, and, last but not least, their intuitive design paradigm, game developers are provided with an alternative approach to design games that otherwise might be impossible to implement in an efficient manner. We illustrate this potential using a sample mobile game.

International Journal on Semantic Web and Information Systems, 2014

During the last years, mobile computing has been the focus of many research efforts, due mainly t... more During the last years, mobile computing has been the focus of many research efforts, due mainly to the ever-growing use of mobile devices. In this context, there is a need to manage dynamic data, such as location data or other data provided by sensors. As an example, the continuous processing of location-dependent queries has been the subject of thorough research. However, there is still a need of highly expressive ways of formulating queries, augmenting in this way the systems' answer capabilities. Regarding this issue, the modeling power of Description Logics (DLs) and the inferring capabilities of their attached reasoners could fulfill this new requirement. The main problem is that DLs are inherently oriented to model static knowledge, that is, to capture the nature of the modeled objects, but not to handle changes in the property values (which requires a full ontology reclassification), as it is common in mobile computing environments (e.g., the location is expected to vary ...

ABSTRACT In the last few years, the use of ontologies has spread thanks to the irruption of the S... more ABSTRACT In the last few years, the use of ontologies has spread thanks to the irruption of the SemanticWeb. They have become a crucial tool in information systems as they explicitly state the meaning of information, making it possible to share it and to achieve higher levels of interoperability. However, being knowledge representation models as they are, other �fields can take advantage of their characteristics to extend their capabilities. In particular, in the context of Embodied Conversational Agents, they can be used to provide them with semantic knowledge and, therefore, enhance their intellectual skills. In this paper, we propose an approach to explore the synergies between these technologies. Thus, we have developed a multimodal ECA that exploits the knowledge provided by the Linked Data initiative to help users in their search information tasks. Based on a semantic-guided keyword search, our approach is flexible enough to: 1) deal with different Linked Data repositories and 2) handle different search/knowledge domains in a multilingual way. To illustrate the potential of our approach, we have focused on the case of DBpedia, as it mirrors the information stored in the Wikipedia, providing a semantic entry to it.

Proceedings of the 36th Annual ACM Symposium on Applied Computing, 2021

Understanding the user's intention is crucial in human-machine interaction. When dealing with tex... more Understanding the user's intention is crucial in human-machine interaction. When dealing with text input, Word Sense Disambiguation (WSD) techniques play an important role. WSD techniques typically require well-formed sentences as context to operate, and predefined catalogues of word senses. However, such conditions do not always apply, such as when there is a need to disambiguate keywords from a query, or sets of tags describing any Web resource. In this paper, we propose a keyword disambiguation method based on the semantic relatedness between words and ontological terms. Taking advantage of the semantic information captured by word embeddings, our approach maps a set of input keywords to their meanings within a given target ontology. We focus on situations where the available linguistic information is very scarce, hampering natural language based approaches. Experimental results show the feasibility of our approach without previous training for target domains.

New advances in mobile computing devices allow us to think about new approaches such as a functio... more New advances in mobile computing devices allow us to think about new approaches such as a functional ubiquitous computer. In particular, it would be very useful for users to move from one place to another having all his data and applications available, in the same state, and without doing anything special (a real ubiquitous computer). In this paper we propose an infrastructure that makes the user independent from a specific computer/location. The intelligent environment detects the location of the user and presents his computer workspace on the closest computer. The system finds the optimal balance between remote and local access to user files and applications, to reduce the use of remote resources whenever possible. This is achieved by using mobile agents that manage the mobility of users. All the data (and applications' state) "move" wherever the user goes, giving him the impression of controlling a computer just by getting close to it. We have done some tests that proof the flexibility of our approach.

Abstract. The need for location-based services has motivated an important research effort in the ... more Abstract. The need for location-based services has motivated an important research effort in the efficient processing of location-dependent queries. Most of the existing approaches only deal with locations at maximum precision (e.g., GPS coordinates). However, due to imprecision or expressivity requirements, there are situations in which locations must be handled at different granularity levels (e.g., neighborhoods, cities, states, etc.). Indeed, whenever a set of locations are represented together as a granule, a meaning is implicitly given to the set. So, the use of different granularities brings different semantics to the location data. In this paper, we propose the use of semantic location granules to enhance the expressivity of location-dependent queries. This is done by exploiting the semantic information that is asserted about different granularity levels. This information could be, for example, the cost incurred by a moving object to traverse a spatial area or a requirement ...

Abstract. Regarding web searches,users havebecome used to keywordbased search interfaces due to t... more Abstract. Regarding web searches,users havebecome used to keywordbased search interfaces due to their ease of use. However, this implies a semantic gap between the user’s information need and the input of search engines, as keywords are a simplification of the real user query. Thus, the samesetofkeywordscanbeusedtosearchdifferentinformation.Besides, retrieval approaches based only on syntactic matches with user keywords are not accurate enough when users look for information not so popular on the Web. So, there is a growing interest in developing semantic search engines that overcome these limitations. In this paper, we focus on the front-end of semantic search systems and propose an approach to translate a list of user keywords into an unambiguous query, expressed in a formal language, that represents the exact semantics intended by the user. We aim at not sacrificing any possible interpretation while avoiding generating semantically equivalent queries. To do so, we apply several s...

Abstract. The massive spread of mobile computing in our daily lives has attracted a huge communit... more Abstract. The massive spread of mobile computing in our daily lives has attracted a huge community of mobile apps developers. These developers can take advantage of the benefits of semantic technologies (such as knowledge sharing and reusing, knowledge decoupling, etc.) to enhance their applications. Moreover, the use of semantic reasoners would enable them to create more intelligent applications capable of inferring logical consequences from the knowledge considered. However, using semantic APIs and reasoners on current Android-based devices is not problem-free and, currently, there are no remarkable efforts to enable mobile devices with semantic reasoning capabilities. In this paper, we analyze whether the most popular current available DL reasoners can be used on Android-based devices. We evaluate the efforts needed to port them to the Android platform, taking into account its limitations, and present some tests to show the performance of these reasoners on current smartphones/ta...