On the Use of Asymmetric Windows for Robust Speech Recognition

This paper deals with the problem of searching for a suitable window for robust speech recognition in noisy conditions. A set of asymmetric windows, so-called DDR _c,w , are proposed which are controlled by two parameters, center c and width w. These windows are derived from the DDR window used in the higher-lag autocorrelation spectrum estimation (HASE) method and act over the OSA (One-Sided Autocorrelation) in order to perform spectral estimation. The two parameters, c and w, allow us to control the level of weight given to the first noisy autocorrelation coefficients and to emphasize the important ones. Finally, it is shown that the best window of the proposed set is the DDR _62,200. This window is centered around the average pitch of human speech and it provides a higher speech recognition performance over the Aurora-2 and Aurora-3 databases than those obtained by previously proposed windows.     

Improving user content privacy on social networks using rights management systems

Currently, millions and millions of users are using online social networks to share their thoughts, experiences and content with online friends. Documents, videos, music and pictures are shared online, relying on the privacy and security controls offered by the social network platforms, with little control from the end user. This creates serious privacy concerns, since the control over the content shared online on the social network is out of the hands of the user. In this paper, the authors propose an approach for content privacy shared on social networks that is user-centric and not based on the social network platform. In order to achieve that, an architecture based on a rights management platform capable of enforcing the necessary security and privacy mechanisms that extend the original controls provided by the social network platform will be presented. That way, users will be able to control their privacy settings and protect their own content, even when they are no longer part of the social network (suspending or deleting its account).     

Programmable SC Biquad Using One Single Capacitor Bank

This paper presents a new technique for programming SC circuits using a single time-multiplexed capacitor bank, achieving a significant reduction in capacitance area. Simulation and experimental results obtained with a programmable biquad low pass filter show the validity of the proposed method.Antonio Torralba was born in Seville, Spain. He received the electrical engineering and Ph.D. degrees from the University of Seville, Seville, Spain, in 1983 and 1985, respectively. Since 1983, he has been with the Department of Electronic Engineering, School of Engineering, University of Seville, where he has been an Assistant professor, Associate Professor (1987), and Professor (1996). He has published 30 papers in journals and more than 80 papers in conferences. His research interests are in the design and modeling of low-voltage analog circuits, analog and mixed-signal design, analog to digital conversion, and electronic circuits and systems with application to control and communication.Alfredo Pérez Vega-Leal was born in Seville, Spain. He received the Electrical Engineering and Ph.D. degrees from the University of Seville, Seville, Spain, in 1998 and 2003, respectively. Since 1995, he has been with the Department of Electronic Engineering, School of Engineering, University of Seville, as research student and became an Associate Professor in 1999. His research interests are related to low-voltage low-power analog circuit design, A/D and D/A conversion.Ramón González Carvajal was born in Seville, Spain. He received the Electrical Engineering and Ph.D. degrees from the University of Seville, Seville, Spain, in 1995 and 1999, respectively. Since 1996, he has been with the Department of Electronic Engineering, School of Engineering, University of Seville, where he has been an Associate Professor (1996), and Professor (2002). He has published more than 100 papers in International Journals and Conferences. His research interests are related to low-voltage low-power analog circuit design, A/D and D/A conversion, and analog and mixed signal processing.     

Adaptive Resource Sharing Strategies for UMTS Multiservice Mobiles

In this paper, a multiservice transmission scheme which joints voice, video, interactive game and signaling is evaluated for the dedicated channel of the Universal Mobile Telecommunications System. The transmission rate for each service is determined by means of an adaptive transport format selection. In the UMTS standard, this selection is based on power allocation provided by radio resource controller, trying to match the Eb/No requirements of the individual services. An appropriate selection of the individual rates of each multiplexed service, taking into account its particular QoS requirements, will provide a more efficient resource management than the transmission only restricted to power allocation. For this purpose, we propose and evaluate a new selection strategy based on buffer occupation, delay requirements and target bit rate keeping power constraints that intends to improve the basic operation trying to minimize the impact of the whole network. Video and game services are multiplexed in upper layers (logical channels) sharing a common transmission rate (transport channel). In this paper, it is proposed a new strategy to share the transmission rate set for this transport channel between both services taking into account their particular requirements. Results show that considering delay constraints provides a more balanced performance of the multiplexed services.     

Transmission Strategies for MISO Downlink MC-CDMA Mobile Systems

This paper proposes two space-frequency schemes with a multi-user pre-filtering technique for downlink (DL) multicarrier code division multiple access (MC-CDMA) systems. We consider the use of antenna arrays at the base station (BS) and a single antenna at the mobile terminal (MT) and derive the proposed multi-user pre-filtering technique that modulates the transmitted signal to eliminate the effects of multiple access interference (MAI) and channel distortions at the mobile terminals, while maintaining low MT complexity. Two types of detectors are considered at the MT: simple despreading and single user equalizers. The performances of the proposed schemes are compared to those of other transmit signal design approaches that have been recently proposed for DL MC-CDMA, considering both typical indoor and pedestrian scenarios, and channel coding based on UMTS specifications.     

Evaluation of the addition of wheat residues in the production of Pinus oocarpa agglomerated panels

Clean Technologies and Environmental Policy - The aim of this research was to evaluate the physical and mechanical properties of Pinus oocarpa wood agglomerated panels produced with the addition of...     

The effect of co-encapsulation of Lactobacillus rhamnosus GG ATCC 53103 with inulin on alginate/chitosan matrix: the viability in fermented soy blend and simulated digestive system

This research verified the ability of Lactobacillus rhamnosus encapsulated with inulin to tolerate the simulated digestive system and their viability in a soy blend. Probiotic encapsulated in alginate-chitosan matrix without inulin presented a better encapsulation efficiency (80.92%) than encapsulation with inulin (57.39%). On the 28th day, the count of probiotics decreased by 3.42 and 1.99 logarithmic cycles of free and encapsulated cells without inulin, respectively. In contrast, the microorganisms encapsulated with inulin showed an increase of 1.26 logs CFU g⁻¹. During gastrointestinal simulation, cell counts decreased by 0.78, 1.55 and 1.95 CFU g⁻¹ logs for encapsulated cells without inulin, free and encapsulated with inulin, respectively. Sensory panellists liked the fermented soy blend with encapsulated lactobacilli, and this result shows the possibility to create new probiotic foods of plant origin. Therefore, the alginate/chitosan matrix can be considered adequate for the encapsulation of L. rhamnosus. The inulin reduces the encapsulation efficiency and increases the cell loss in gastrointestinal simulation. Considering cellular losses, the best option for preparing a fermented soy blend is to use L. rhamnosus encapsulated without inulin.