Victoria Beltran
Polytechnic University of Catalonia
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Publication
Featured researches published by Victoria Beltran.
international semantic web conference | 2011
Victoria Beltran; Knarig Arabshian; Henning Schulzrinne
The World Wide Web is becoming increasingly personalized as users provide more of their information on the Web. Thus, Web service functionality is becoming reliant on user profile information and context in order to provide user-specific data. In this paper, we discuss enhancements to SECE (Sense Everything, Control Everything), a platform for context-aware service composition based on user-defined rules. We have enhanced SECE to interpret ontology descriptions of services. With this enhancement, SECE can now create user-defined rules based on the ontology description of the service and interoperate within any service domain that has an ontology description. Additionally, it can use an ontology-based service discovery system like GloServ as its service discovery back-end in order to issue more complex queries for service discovery and composition. This paper discusses the design and implementation of these improvements.
IEEE Internet Computing | 2014
Victoria Beltran; Emmanuel Bertin; Noel Crespi
Secured interpersonal communications should come with asserted user identities and trust between the involved parties. No single trust model exists in Web Real-Time Communications services, so neither is there a single identity architecture. The authors discuss different models for provisioning user identity and their impact on user privacy.
multimedia and ubiquitous engineering | 2008
Xavier Sanchez-Loro; Victoria Beltran; Jordi Casademont; Marisa Catalan
Traditionally, cellular wide area networks like UMTS are used as Internet access networks for particular users but, in some cases, they can be employed to provide Internet access to other smaller networks as well. The main inconvenient is that cellular networks have not the same bandwidth than wired networks and therefore, the cellular channel becomes a network bottle-neck. To help to mitigate this situation and in order to improve the users experience different optimization techniques exist, especially in web traffic. This paper studies first the existing synergies at HTTP layer between device capabilities expression, content negotiation, channel optimization and content adaptation. And secondly, it presents a system where HTTP requests transmission is optimized, showing a significant improvement in response time by means of HTTP header reduction over the cellular channel. In order to obtain a successful browsing experience, headers should be restored when reaching the Internet. This dynamic header reconstruction allows giving enriched and more expressive information about users device and browser capabilities. Thus navigation speed and users QoE can be enhanced by means of dynamic content negotiation in order to obtain adapted (and lighter) content and responses from web servers and adaptation proxies alike.
Analytical and Bioanalytical Chemistry | 2016
Victoria Beltran; Nati Salvadó; Salvador Butí; T. Pradell
AbstractResins obtained from Pinus genus species have been widely used in very different fields throughout history. As soon as the resins are secreted, molecular changes start altering their chemical, mechanical and optical properties. The ageing processes are complex, and the chemical and structural changes associated with resin degradation are not yet fully known. Many questions still remain open, for instance changes happening in pimaranes, one of the two diterpenoid constituents of the resin. A systematic study of the ageing process of Pinus resins is done through Fourier transform infrared spectroscopy (FTIR) using chemical standards and complementing the obtained results with gas chromatography coupled to mass spectrometry (GC/MS) analysis when necessary. Moreover, long-term degradation processes are also investigated through the analysis of a selection of dated historical resins. This study overcomes the limitations of GC/MS and brings new information about the reactions and interactions between molecules during Pinus resin ageing processes. It also provides information about which bonds are affected and unaffected, and these can be used as specific markers of the degradation and of the resins themselves. Graphical AbstractChanges in the IR spectral features due to the Pinus resin ageing processes
IEEE Internet Computing | 2012
Omer Boyaci; Victoria Beltran; Henning Schulzrinne
Sense Everything, Control Everything (SECE) is an event-driven system that lets nontechnical users create services that combine communication, location, social networks, presence, calendaring, and physical devices such as sensors and actuators. SECE combines information from multiple sources to personalize services and adapt them to changes in the users context and preferences. Events trigger associated actions, which can control email delivery, change how phone calls are handled, update the users social network status, and set the state of actuators such as lights, thermostats, and electrical appliances.
Analytical Chemistry | 2015
Victoria Beltran; Nati Salvadó; Salvador Butí; Gianfelice Cinque; Katia Wehbe; T. Pradell
Precise microanalytical techniques are essential in many fields such as cultural heritage materials, showing complex layered microstructures containing a wide range of materials of diverse nature and hardness. Noninvasive sample manipulation and preparation is required to avoid, as much as possible, sample contamination, which may strongly limit the materials identification. The method proposed consists in the application of thin gold or carbon protecting layers before embedding the samples in synthetic resin for microtoming. The validity and optimal procedure is checked for those materials most often found on the surface of paintings: varnishes (natural resins and wax). An artwork sample is similarly prepared and analyzed by optical microscopy (OM), scanning electron microscopy (SEM/EDS), micro-infrared spectroscopy (μFTIR/μSR-FTIR), and X-ray diffraction (μSR-XRD) with synchrotron light.
Journal of Natural Products | 2017
Victoria Beltran; Nati Salvadó; Salvador Butí; Gianfelice Cinque; T. Pradell
The resin extracted from the species of the Pinus genus (Pinaceae family) is a widely used material. Primarily, resins are made up of two types of diterpenoids: abietanes and pimaranes. Their composition changes with aging, affecting their chemical and physical properties; however, the chemical changes that occur during aging are not yet fully known. Understanding the evolution of pimaranes and abietanes and the chemical composition of the aged resins is essential to make the most of this substance and of its derivatives. A systematic study of the aging of Pinus resin with Raman complemented with infrared (IR) spectroscopy was carried out. This study provided new information about the interactions among the constituting molecules in resins aged over many years. In particular the formation of intermolecular hydrogen bonds in aged samples was detected for the first time, and the formation of acid anhydrides from the reaction between pimaranes was demonstrated. Furthermore, Raman and IR spectra band assignments are proposed, and the specific markers of the main compounds of the resin are tagged. This will facilitate the qualitative analysis of resin compounds.
Analytical Methods | 2016
Nati Salvadó; Salvador Butí; T. Pradell; Victoria Beltran; Gianfelice Cinque; Jordi Juanhuix; Lídia Font; Rosa Senserrich
Micro-Infrared Spectroscopy (μSR-FTIR) and X-ray diffraction (μSR-XRD) with synchrotron light, Gas Chromatography/Mass Spectrometry (CG/MS), Optical Microscopy (OM) and Scanning Electron Microscopy (SEM/EDS) were used to identify and obtain the distribution of complex mixtures of calcium salts of low molecular weight organic acids (LMWOA) in micro-layered micro-samples. Filamentous fungi produce LMWOA that can react with metal cations producing stable salts. These substances were found in the dark spots covering the surfaces of Saint Michaels Chapel wall paintings of the Royal Monastery of Pedralbes in Barcelona linking them to old fungi activity. The presence of glycerol likewise related to the fungi activity is also identified in the layers.
International Journal of Cooperative Information Systems | 2010
Victoria Beltran; Josep Paradells
Presence information was the key enabler to the great success of instant messaging applications. First, this information was limited to simple binary states such as online, offline or busy. However, this is, currently, evolving towards a much more generic, flexible concept to include all context that allows users or applications to adapt and control communications in a more efficient and personalized manner. Presence paves the way for the deployment of advanced communication services and is therefore a key component in the Next-Generation Networks (NGNs). These networks aim to unify fixed and mobile networks in order to provide users with global connectivity to always-on multimedia services. The main barrier to the implantation of next-generation presence-based services is the great amount of traffic involved in the distribution of presence information across domains. We study two strategies described in IETF drafts and one novel solution for reducing inter-domain presence traffic. We present the analytical formulas that calculate the traffic for the three strategies. Building on the analytical results, we analyze the factors that have impact on these strategies and study the suitability of each one under different conditions.
international conference on information networking | 2008
Victoria Beltran; Josep Paradells
The mobility of users of Internet services, smarter phones and mobile networks with more coverage and broadband are synergistically driving towards overall global IP connectivity. In order to reach Fixed Mobile Convergence (FMC), personalization is a key feature in providing advanced services that are of value to customers. The user communitys acceptance of FMC services will motivate industry and operators to collectively embrace global connectivity. Presence information, which was initially designed to describe the willingness of users to communicate with others, has become a powerful tool for personalizing services that manage user communications. We propose a logical presence functionality running as a presence proxy that can be integrated into a home gateway or femtocell as a value-added service or in the operator network. This presence proxy permits users to manage their presence and establish communication and privacy models in a personalized way. An important feature of this solution is that it enables presence traffic to be optimized if necessary. In addition, the proxy is able to integrate functions to make Internet access or multimedia sessions easier or more efficient for users.