Antonio Ruiz-Martínez

Feature-based opinion mining in financial news: An ontology-driven approach

Financial news plays a significant role with regard to predicting the behaviour of financial markets. However, the exponential growth of financial news on the Web has led to a need for new technologies that automatically collect and categorise large volumes of information in a fast and easy manner. Sentiment analysis, or opinion mining, is the field of study that analyses people’s opinions, moods and evaluations using written text on Web platforms. In recent research, a substantial effort has been made to develop sophisticated methods with which to classify sentiments in the financial domain. However, there is a lack of approaches that analyse the positive or negative orientation of each aspect contained in a document. In this respect, we propose a new sentiment analysis method for feature and news polarity classification. The method presented is based on an ontology-driven approach that makes it possible to semantically describe relations between concepts in the financial news domain. The polarity of the features in each document is also calculated by taking into account the words from around the linguistic expression of the feature. These words are obtained by using the ‘N_GRAM After’, ‘N_GRAM Before’, ‘N_GRAM Around’ and ‘All_Phrase’ methods. The effectiveness of our method has been proved by carrying out a set of experiments on a corpus of 1000 financial news items. Our proposal obtained encouraging results with an accuracy of 66.7% and an F-measure of 64.9% for feature polarity classification and an accuracy of 89.8% and an F-measure of 89.7% for news polarity classification. The experimental results additionally show that the N_GRAM Around method provides the best average results.

ONLI: An ontology-based system for querying DBpedia using natural language paradigm

Abstract The Semantic Web has emerged as an extension of the current Web, in which Web content has well-defined meaning through the addition of logic-based metadata. However, current mechanisms for information retrieval from semantic knowledge bases restrict their use to only experienced users. To address this gap, the natural language processing (NLP) is deemed to be very intuitive from a use point of view, due to it hides the formality of a knowledge base as well as the executable query language. This paper presents a novel ontology-based information retrieval system for DBpedia called ONLI (Ontology-based Natural Language Interface). ONLI proposes the use of an ontology model in order to represent both the syntactic question’s structure and the question’s context. This model allows inferring the answer type expected by the user through an established question’s classification. These features allow reducing the search space thus increasing the probability of providing the correct answer. From this perspective, ONLI was evaluated in terms of their ability to find the correct answer into DBpedia’s content, achieving promising results and proving to be very useful to non-experienced users.

Review: A survey on solutions and main free tools for privacy enhancing Web communications

Concern for privacy when users are surfing on the Web has increased recently. Nowadays, many users are aware that when they are accessing Web sites, these Web sites can track them and create profiles on the elements they access, the advertisements they see, the different links they visit, from which Web sites they come from and to which sites they exit, and so on. In order to maintain user privacy, several techniques, methods and solutions have appeared. In this paper we present an analysis of both these solutions and the main tools that are freely distributed or can be used freely and that implement some of these techniques and methods to preserve privacy when users and surfing on the Internet. This work, unlike previous reviews, shows in a comprehensive way, all the different risks when a user navigates on the Web, the different solutions proposed that finally have being implemented and being used to achieve Web privacy goal. Thus, users can decide which tools to use when they want navigate privately and what kind of risks they are assuming.

Designing a Generic Collaborative Working Environment

Groupware provides an essential support for the maintenance of knowledge management in many organizations. Accordingly, the use of groupware systems has become widespread. However, still some problems regarding the way in which business process are implemented exist, because they require the communication between several of these groupware systems to fulfill all required objectives in the organization. For that reason, interoperability issues have taken a vital role in the business sector. In this area, one of the leading technologies is the Web service standard. In this paper we describe the design of a generic collaborative working environment to provide the basis for allowing interoperability with several groupware systems. We also reflect how Web services technologies are used in the design of this environment.

Teaching Advanced Concepts in Computer Networks: VNUML-UM Virtualization Tool

In the teaching of computer networks the main problem that arises is the high price and limited number of network devices the students can work with in the laboratories. Nowadays, with virtualization we can overcome this limitation. In this paper, we present a methodology that allows students to learn advanced computer network concepts through hands-on experience with the VNUML-UM virtualization tool, which is offered freely as a resource for the practical teaching of mobility, load balancing, and high availability. To verify the utility of using the VNUML-UM virtualization tool in the teaching of advanced computer network concepts, we have performed some opinion polls to the students during the last three academic years. The obtained results confirm that our students agree that the VNUML-UM enables an enhanced learning process of the different concepts and their practical skills. This perception is also confirmed by the final marks obtained by the students, which have considerably improved along the years. To the best our knowledge, this paper presents the first experience that provides results on the use of virtualization to teach advanced concepts in the field of computer networks.

KAMU: providing advanced user privacy in Kerberos multi-domain scenarios

In Next Generation Networks, Kerberos is becoming a key component to support authentication and key distribution for Internet application services. However, for this purpose, Kerberos needs to rectify certain deficiencies, especially in the area of privacy, which allow an eavesdropper to obtain information of the services users are accessing. This paper presents a comprehensive privacy framework that guarantees user anonymity, service access unlinkability and message exchange unlinkability in Kerberos both in single-domain and multi-domain scenarios. This proposal is based on different extensibility mechanisms already defined for Kerberos, which facilitate its adoption in already deployed systems. Apart from evaluating our proposal in terms of performance to prove its lightweight nature, we demonstrate its capability to work in perfect harmony with a widely used anonymous communication system like Tor.

Smartcard-Based e-Coin for Electronic Payments on the (Mobile) Internet

Nowadays e-purses are not being offered as payment method on the Internet. This is mainly due to the fact that vendors have to integrate in their devices a security application module (SAM) to exchange security messages between the e-purse and that module during the payment phase. In this paper we introduce a new payment method that combines the main advantages of e-purses and the use of e-coins to make payments. This proposal does not need either a SAM to make and verify payments on the Internet nor an on-line e-coin validation. Thus, we introduce the possibility that this e-purse can be easily integrated in payment applications that vendors offer on the Internet. Moreover, our proposal is based on the use of Javacard applets with the aim of being used in both traditional Javacard-compliant smartcards and SIM smartcards, which involves that our proposal might be considered as a mobile payment system.

A mobile network operator-independent mobile signature service

Electronic signature (e-signature) is an important element in electronic commerce and government applications because it guarantees non-repudiation of transactions. E-signatures generated in a secure signature creation device can be considered legally equivalent to a handwritten signature. Mobile devices based on SIM/USIM cards, which are broadly extended, are the ideal devices to create these e-signatures (named mobile signatures or m-signatures). Furthermore, thanks to m-signatures the development of m-signature-based applications becomes simpler for mobile application/service providers. There are several solutions to create m-signatures. However, current solutions present some problems: either they require that the solution is developed by every mobile network operator or the components to implement it in the mobile handset are too complex. As a solution to these problems we present an m-signature service that is not linked to a mobile network operator and where the client has more control over the signatures to perform them in an easier way. This paper presents the description and analysis of this new m-signature service as well as the prototype that is being tested in the University of Murcia.

Design and implementation of a generic per‐fee‐link framework

Purpose – This paper aims to present a viable approach for designing and implementing a generic per‐fee‐link framework. It also aims to design this framework to be used with any payment protocol and test it with two existing ones.Design/methodology/approach – The paper presents a per‐fee‐link framework based on several generic components. These components have been developed and tested in order to prove the viability of the proposed framework.Findings – The results show that is possible to establish a per‐fee‐link framework. Four core components are defined: first, the different modules needed for browsers and web servers, second, an extended payment protocol (EPP), which negotiates the payment protocol to use and encapsulates its related messages, third, an API for e‐wallets, which is independent of the payment protocol, to incorporate the protocols to use with EPP and finally, the definition of a per‐fee‐link that associates payment information to a link.Practical implications – The framework presented ...

SIP extensions to support (micro)payments

SIP is a protocol designed to create and manage multimedia sessions such as telephone calls over the Internet, distributed conferences, or, in general, every kind of communication between two or more peers. The introduction of payment in SIP is an interesting idea in order to charge for this media services. This payment services have been proposed in several scenarios such as charging for accessing to services, microbilling or as a solution to SPAM in VoIP systems. In this context, there is a proposal for making payments on SIP that is based on SAML. However, this proposal is not good enough to make low payments or micropayments because involves that the payment service provider participates in every payment. This implies that the transaction costs are high and therefore it is not suitable for this kind of payments. Additionally, this proposal only deals with the scenario in which the payment covers the whole session. Finally, this proposal does not take into account that streams with different quality could be used in the session, and therefore the amount to pay could be different. In response to these limitations we propose a new extension for supporting payments on SIP which, being payment-independent protocol, solves interoperability problems and links payment information to requests. For this purpose, we have extended both SDP and SIP to facilitate the access to SIP services based on payment. The extension supports an offer/answer model that allows the choice of the quality of the streams as well as the payment method to use. Furthermore, it is extensible and not only supports payment but also more complex business models such as loyalty models, credentials and subscriptions. Thus, we facilitate the incorporation of new payment methods and business models in the vendors software. This paper describes this extension as well as some scenarios where it can be applied.