General logarithmic image processing convolution

The logarithmic image processing model (LIP) is a robust mathematical framework, which, among other benefits, behaves invariantly to illumination changes. This paper presents, for the first time, two general formulations of the 2-D convolution of separable kernels under the LIP paradigm. Although both formulations are mathematically equivalent, one of them has been designed avoiding the operations which are computationally expensive in current computers. Therefore, this fast LIP convolution method allows to obtain significant speedups and is more adequate for real-time processing. In order to support these statements, some experimental results are shown in Section V

Lightweight method of shuffling overlapped data-blocks for data integrity and security in WSNs

Wireless Sensor Networks (WSN) consist of devices with limited resources to explore and sense the environment in a cooperative way. Security, mainly in terms of guaranteeing the data integrity, is a primary issue for many applications, but with an extra energy cost. Thus, trade-off is required between security level and energy consumption in real applications. First of all, a brief survey about security methods, focusing in data integrity, in WSN is implemented. The objective of this paper is to propose a new data integrity method with medium security levels and low energy cost. Therefore, we propose a new and lightweight mechanism for data integrity with overlapping blocks in WSNs. Hence, an attacker will spend much time and effort to interpret and alter the packets. The experiments were performed using TinyOS 2.1 operating system and TelosB nodes for measuring the overhead in terms of energy consumption, memory, and packet size. Moreover, the receiver is able to detect tampering packets and request those retransmission data. An attacker would require huge amounts of memory and processing time to extract the original information, even for small-sized data blocks. Thus, this fact makes this approach a simple, yet effective, mechanism to protect data whilst enhancing the data integrity

License Plate Detection based on Genetic Neural Networks, Morphology, and Active Contours

This paper describes a new method for License Plate Detection based on Genetic Neural Networks, Morphology, and Active Contours. Given an image is divided into several virtual regions sized 10×10 pixels, applying several performance algorithms within each virtual region, algorithms such as edge detection, histograms, and binary thresholding, etc. These results are used as inputs for a Genetic Neural Network, which provides the initial selection for the probable situation of the license plate. Further refinement is applied using active contours to fit the output tightly to the license plate. With a small and well–chosen subset of images, the system is able to deal with a large variety of images with real–world characteristics obtaining great precision in the detection. The effectiveness for the proposed method is very high (97%). This method will be the first stage of a surveillance system which takes into account not only the actual license plate but also the model of the car to determine if a car should be taken as a threat

Homomorphic Filtering for Improving Time Synchronization in Wireless Networks

Wireless sensor networks are used to sample the environment in a distributed way. Therefore, it is mandatory for all of the measurements to be tightly synchronized in order to guarantee that every sensor is sampling the environment at the exact same instant of time. The synchronization drift gets bigger in environments suffering from temperature variations. Thus, this work is focused on improving time synchronization under deployments with temperature variations. The working hypothesis demonstrated in this work is that the clock skew of two nodes (the ratio of the real frequencies of the oscillators) is composed of a multiplicative combination of two main components: the clock skew due to the variations between the cut of the crystal of each oscillator and the clock skew due to the different temperatures affecting the nodes. By applying a nonlinear filtering, the homomorphic filtering, both components are separated in an effective way. A correction factor based on temperature, which can be applied to any synchronization protocol, is proposed. For testing it, an improvement of the FTSP synchronization protocol has been developed and physically tested under temperature variation scenarios using TelosB motes flashed with the IEEE 802.15.4 implementation supplied by TinyOS

Digital Systems Laboratory for Visually Impaired Students

Comunicación presentada al 2nd ACM Workshop on Methods and Cases in Computing Education for the European Higher Education Area, celebrado en Barcelona el 22 de abril de 2009.This paper describes how the practical sessions of the Digital Systems Laboratory within the Computer Science Degree have been adapted to allow a visually impaired student to take part in the practical sessions. Regular students use a computer--aided design tool (OrCAD) for digital design in their practical assignments. This work shows how the use of special instrumentation allows visually impaired students to work with regular students in the same lab, where the CAD tool is installed. The teaching methodology and the obtained assessments are introduced here. Some specific practical materials have been designed and they are described in this work; the design of a special buzzer is also presente

Aplicación de PCA y técnicas bayesianas a la clasificación de píxeles basada en color

En este trabajo se propone un método para la clasificación de píxeles en base a su color. A partir de un conjunto de variables que caracterizan un píxel según su color se determinará cuáles de éstas son las más representativas y se realizará la clasificación propiamente dicha. Para ello nuestro método consta de dos fases: en la primera se aplica PCA para obtener el conjunto de variables características más informativas; en la segunda, dichas variables se utilizan como patrones de las clases de un clasificador bayesiano. El método se ilustra a través de varios experimentos

Non-Invasive Forehead Segmentation in Thermographic Imaging

The temperature of the forehead is known to be highly correlated with the internal body temperature. This area is widely used in thermal comfort systems, lie-detection systems, etc. However, there is a lack of tools to achieve the segmentation of the forehead using thermographic images and non-intrusive methods. In fact, this is usually segmented manually. This work proposes a simple and novel method to segment the forehead region and to extract the average temperature from this area solving this lack of non-user interaction tools. Our method is invariant to the position of the face, and other different morphologies even with the presence of external objects. The results provide an accuracy of 90% compared to the manual segmentation using the coefficient of Jaccard as a metric of similitude. Moreover, due to the simplicity of the proposed method, it can work with real-time constraints at 83 frames per second in embedded systems with low computational resources. Finally, a new dataset of thermal face images is presented, which includes some features which are difficult to find in other sets, such as glasses, beards, moustaches, breathing masks, and different neck rotations and flexions

Professional certification as a teaching tool in Computer Science Degree at the Higher Polytechnic School of Cordoba

Existen múltiples empresas que emiten certificaciones de competencias profesionales dentro del ámbito de las Ingenierías. Estas certificaciones están siendo muy demandadas por las empresas empleadoras ya que permiten demostrar la cualificación de los solicitantes desde un punto de vista teórico y práctico muy exigente. Esto ha llevado a que muchos alumnos y egresados hayan tomado cursos de preparación para los exámenes de certificación. Una de las más relevantes es CISCO, que realiza certificaciones de competencias de Redes de Computadores. Un grupo de profesores de la EPSC de la Universidad de Córdoba ha planteado adaptar los contenidos de diversas asignaturas de la Titulación Oficial de Grado en Ingeniería Informática para que el alumnado cubra todos los requisitos formativos (tanto teóricos como prácticos) exigidos por la empresa CISCO para las diversas certificaciones en materia de Redes de Comunicación entre Ordenadores. Además, esta adaptación debe hacerse sin alterar el documento Verifica, aprobado por la Agencia Nacional de Acreditación y Evaluación (ANECA).There are a lot of enterprises which provide certifications of knowledge and skills in professional competences within the Engineering field. These certifications are highly demanded by employers, because they demonstrate the qualification of the applicants from a very demanding theoretical and practical point of view. Thus, a lot of students and graduates have enrolled in training courses for the certification exams. One of the most important corporations is CISCO, which provides certifications in the field of Computer Networking. A group of professors from the Higher Polytechnic School of Cordoba from the University of Cordoba (Spain) has adapted the contents of several subjects of the Computer Science Degree, in order to cover all the educational requirements required by CISCO for the Computer Networking field. Besides, this adaptation has to be taken without any modification in the VERIFICA document, approved by the Spanish National Certification and Evaluation Agency (ANECA)

Desarrollo de un sistema de toma de decisiones autónomo y ejemplo de aplicación a servicios de seguridad bajo demanda

Existen multitud de sistemas de adquisición de datos autónomos basados en diferentes metodologías, muchos de ellos se imparten en la educación universitaria y otros por el contrario surgen de un exhaustivo trabajo de investigación científica. Estos sistemas se aplican hoy en día en un gran número de áreas, siendo todas ellas muy diversas aunque con importantes nexos comunes. En el presente artículo se propone, a partir de un proyecto fin de carrera, un sistema autónomo de adquisición de datos y reconocimiento del entorno, con un alto índice de escalabilidad e integración a nuevos espacios. Para probar su eficacia se propone también una aplicación robotizada que utiliza estas características en el área de la seguridad, un campo en el que resultan especialmente claras las propiedades diferenciadoras del método propuesto