José Luis Sánchez

Factors that influence the attitude of East European residents in Spain towards living kidney donation

Emigration from East European (EE) countries into the South East of Spain (SES) is becoming more common. The objective of this study was to analyse the attitude towards living kidney donation in this group. A sample of residents (n = 320) in the SES who come from EE was obtained randomly and stratified by a respondent’s nationality (November‐05 to April‐06). Attitude was evaluated using a validated questionnaire that was completed anonymously and was self‐administered. Control group: native Spanish citizens. The questionnaire completion rate was 83% (n = 265). A total of 83% (n = 220) were in favor of related living donation. Attitude is similar to that of the urban control group (P = 0.0534) and more positive than that prevalent in the rural setting (P < 0.001). The variables that were related to attitude included: a respondent’s marital status (P < 0.001); the country of origin (P = 0.014); attitude towards deceased donation (P < 0.001); having discussed the subject within the family (P < 0.001); a respondent’s belief that he might need a transplant organ (P = 0.002) and concern about possible ‘mutilation’ after donation (P < 0.001). There is a favorable attitude towards related living kidney donation among EE who are resident in the SES and this attitude is closely related to attitude towards deceased donation, the attitude of one’s family and feelings of reciprocity.

Using social networks at university: The case of school of computer science

At present, not all of the universities understands the usefulness of social networks for teaching and working insertion. However, both the teachers and the students make use of them. In USA, 100% of the universities make use of social networks in some way. The most widely used social network among American students is Facebook (98%), followed by Twitter (84%) and Linkedin (47%). In this paper, different uses of social networks in education and working insertion at School of Computer Science of University of La Laguna will be described (educational use, work insertion and social media).

A BCD-based architecture for fast coordinate rotation

Although radix 10 based arithmetic has been gaining renewed importance over the last few years, decimal systems are not efficient enough and techniques are still under development. In this paper, an improvement of the CORDIC (coordinate rotation digital computer) method for decimal representation is proposed and applied to produce fast rotations. The algorithm uses BCD operands as inputs, combining the advantages of both decimal and binary systems. The result is a reduction of 50% in the number of iterations if compared with the original Decimal CORDIC method. Finally, we present a hardware architecture useful to produce BCD coordinates rotations accurately and fast, and different experiments demonstrating the advantages of the new method are shown. A reduction of 75% in a single stage delay is obtained, whereas the circuit area just increases in about 5%.

EZW-based image compression with omission and restoration of wavelet subbands

It is well known that multimedia applications provide the user with information through different methods (text, data, graphics, images, audio, video, etc.) which must be digitally represented, transmitted, stored and processed. Due to the fact that there is an increasing interest in developing high definition systems, multimedia applications are demanding, among others, higher bandwidth resources and more memory requirements in embedded devices. Therefore, it is essential to use compression techniques to reduce the time requirements of these new applications. This work aims to design an EZW-based image compression model, which makes use of the omission and restoration of wavelet subbands, providing high compression rates, good quality standards and low computation time requirements. The results obtained show that our method satisfies these assumptions and can be integrated in new multi-media devices.

Colour Image Compression Based on the Embedded Zerotree Wavelet

In recent years, some of the most emerging applications in multimedia data processing are wireless/mobile multimedia systems and streaming content over the Internet. Both applications require flexible image data compression for storage or transmission proposals. Wavelet-based image compression schemes, such as the Embedded Zerotree Wavelet, obtain excellent results for these proposals and have been object of intensive research. In this work we propose an EZW-based compression method for colour images, based on the omission and restoration of wavelet subbands; our method achieves high compression rates and low computation times, combining, therefore, the advantages from both DCT and wavelet based compression algorithms.

A Fuzzy Approach to Skin Color Detection

Skin detection is a useful tool for many subsequent image processing tasks, such as face detection, face tracking or human-computer interfaces. In many cases, using a skin color detection scheme is related to a proper representation of the color space chosen to interpret image information. In this work, we propose a fuzzy system for detecting skin in the RGB color space, so that each color plane is modeled using fuzzy sets. As a consequence, the development of the membership functions, the inference system and the defuzzifying process are described throughout this paper. The experiments have been performed with the XM2VTS and VALID face databases and the results show that our system has high detection rates and low false positive rates compared to other similar skin color detectors.

A client/server implementation of an encryption system for fingerprint user authentication

Purpose – Cryptography has become an essential feature for many current technological applications. Cryptographic methods are usually divided into private‐key (or symmetric) and public‐key (or asymmetric) algorithms. The purpose of this paper is to propose a client/server architecture to efficiently authenticate users by means of their fingerprint biometric feature. To do this, the personal data of each user are acquired at the client and, afterwards, they are conveniently encrypted using a combination of up‐to‐date symmetric and asymmetric cryptographic algorithms.Design/methodology/approach – First the main issues related to public‐key and private‐key cryptography, including well‐known algorithms, such as data encryption standard and Rijndael methods are reviewed. After that, a proposal for the implementation of a client/server architecture to authenticate users by means of fingerprint features is proposed.Findings – The results of the experiments show that such architecture is optimal for being applied...

A Cordic-based Architecture for High Performance Decimal Calculations

Decimal arithmetic supported by digital computers has been gaining renewed importance over the last few years. However, the development of high performance radix 10-based systems is still incipient. In this paper, a modification of the CORDIC method for decimal arithmetic is proposed. The resulting algorithm works with radix 10 operands and combines decimal arithmetic with elementary angles so as to reduce the number of iterations required to achieve certain precision. Different experiments showing the advantages of the new method compared with the original decimal CORDIC method are also described. Finally, an architecture for the method implemented on FPGA is proposed.

Blogs: A learning tool proposal for an Audiovisual Engineering Course

Digital Signal Processors is an optional course in the Audiovisual Engineering Degree of the University of Alicante. This year a pilot project on developing a blog for the course has been introduced (http://blogs.ua.es/pds0910). This way, students must complete - working collaboratively- a set of assigned blog entries on different extension tasks related to the concepts taught in the theory sessions. The blog entries have been always supervised by the teaching staff, who act as system administrators, as well. Students had a very positive attitude towards this learning tool, allowing us to develop new strategies for the upcoming semesters.