TSC

This paper addresses the problem of execution time estimation for tasks in a software pipeline independent of the application structure or the underlying architecture. A regression model is developed to obtain the estimates from previously observed data. To improve the quality of the estimates execution times of predecessor task in a software pipeline is exploited. Since the Model order (number of past observations required to obtain optimal estimate) cannot be determined at design time and to circumvent this, we propose means to dynamically update the order and hence obtain a critical-fit model without resorting to analytical benchmarking or calibration runs. The estimation scheme comprises of two estimation methods, namely 'Wiener-Hopf' and Order-recursive estimation. The selection of the estimation method is automatic and depends on the required quality of the estimate against a user selectable threshold. In order recursion, new model order is obtained in conjunction to estimates, so order recursion solve the system both for order and estimate simultaneously.

This paper presents an along -track interferometry (ATI) study for a bistatic or multiestatic SAR configuration with fixed ground receivers. This technique can be useful for sea current estimation or for any problem of Ground Motion Target Indicator (GMTI). The proximity of the ground receivers to the scene allows to be very sensitivite to velocities with small baselines. This paper also proposes a multibaseline approach for ATI able to diferenciate among different velocity contributions in the same resolution cell. At the end of this paper, some results over real acquired bistatic data will be presented and discussed. The data have been acquired using the C-band SAR Bistatic Receiver for INterferometric Applications (SABRINA) and ESA's ENVISAT satellite, as a transmitter of opportunity.

This paper addresses the problem of stochastic task execution time estimation agnostic to the process distributions. The proposed method is orthogonal to the application structure and underlying architecture. We build the time varying state space model of the task execution time. In the case of software pipelined tasks, to refine the estimate quality, the state-space is modeled as Multiple Input Single Output (MISO) system by taking into account the current execution time of the predecessor task. To obtain nearly Bayesian estimates, irrespective of the process distribution, the sequential Monte Carlo method is applied which form the recursive solution to reduce the overheads and comprises of time update and correction steps.

This paper presents a design of a compact antenna applicator for a microwave colonoscopy system. Although colonoscopy is the most effective method for colorectal cancer detection, it suffers from important visualization restrictions that limit its performance. We recently reported that the contrast between healthy mucosa and cancer was 30-100% for the relative permittivity and conductivity respectively at 8 GHz, and the complex permittivity increased proportionally to the degeneration rate of polyps (cancer precursors). The applicator is designed as a compact cylindrical array of eight antennas attached at the tip of a conventional colonoscope. The design presented here is a proofof-concept applicator composed by one transmitting and one receiving cavity backed U-shaped slot antenna elements fed by an L-shaped microstrip line. The antennas are low profile and present a high isolation at 8 GHz. The antenna performance is assessed with simulations and experimentally with a phantom composed by different liquids.

en entornos educativos puede abarcar varios aspectos del proceso de aprendizaje. La incorporación de TICs en las aulas contribuye, por un lado a reducir la brecha digital tanto de profesores como alumnos y por el otro, debiera ayudar a mejorar la metodología educativa. Sin duda las TICs pueden ser de gran ayuda para llegar a alcanzar los objetivos pedagógicos. En concreto, este estudio tenía por objetivo analizar la manera de incorporar tecnologías de la voz y el procesamiento del lenguaje natural para mejorar el proceso de aprendizaje de la lengua. Para identificar cuales son las características de éste proceso, que aspectos se verán modificados con la incorporación de estas tecnologías y como afectaran las modificaciones a cada aspecto del proceso, en Diciembre de 2010 se organizó una jornada que reunió a distintos sectores sociales directamente involucrados con el ámbito a tratar. Como resultado de ésta jornada, en Abril de 2011, se llevará a cabo una prueba piloto en que se incorporará las tecnologías propuestas en el aprendizaje de inglés y ya se ha empezado a definir un proyecto a medio plazo para buscar financiamiento a nivel estatal o europeo.

Apprenticeship is linked to training. This paper is intended to be a tutorial on how to design, fabricate and measure antennas in an economical and easy way using recycled materials and common electronic devices such as a laptop and an Access Point. Several antenna designs built with household materials are proposed giving practical design and fabrication guidelines. The use of the Wi-Fi band allows linking the experiment with daily life devices and proposing a simple and economical antenna measurement system. The capacity to experiment with antennas from its design to its measurement will definitely stimulate undergraduate or graduate students to get acquainted with the basic topics of antennas and propagation. The paper presented herein was awarded with the first price in the IEEE AP-S Student Challenge 2010 [1], [2].

In the context of the TERASENSE Project an imaging system in the terahertz band will be designed and built. The purpose of this demonstrator is to have an in-house developed instrument to test new technologies and carry out proof-of-concept trials of terahertz imaging systems. In this communication a review of the state of the art of terahertz imaging systems and a system specification and layout of the intended system to be constructed at the UPC is presented.

A subsurface imaging system based on a terahertz time-domain spectrometer (THz-TDS) is described in this paper. The system performance has been simulated in terms of spatial resolution, penetration capabilities and SNR. Moreover, a commercial THz-TDS has been used to perform the proof-of-concept of the described system.

Colorectal cancer is highly preventable by detecting and removing polyps, which are the precursors. Currently, the most accurate test is colonoscopy, but still misses 22% of polyps due to visualization limitations. In this paper, we preliminary assess the potential of microwave imaging and dielectric properties (e.g., complex permittivity) as a complementary method for detecting polyps and cancer tissue in the colon. The dielectric properties of biological tissues have been used in a wide variety of applications, including safety assessment of wireless technologies and design of medical diagnostic or therapeutic techniques (microwave imaging, hyperthermia, and ablation). The main purpose of this work is to measure the complex permittivity of different types of colon polyps, cancer, and normal mucosa in ex vivo human samples to study if the dielectric properties are appropriate for classification purposes. The complex permittivity of freshly excised healthy colon tissue, cancer, and ...

A novel 3D tomographic algorithm for short range cylindrical geometries using UWB frequency range is presented. The algorithm has been applied to breast tumor detection, nevertheless, its non application-specific character permits the use in other applications. The detection capability of the tomographic algorithm is proved through numerical simulations and experimental measurements of canonical and more realistic bodyattached breast phantoms. For the acquisition of the experimental data, a virtual array-based cylindrical measurement setup has been built. At the current stage of development 3 degrees of freedom are available allowing the scanning of bodies with revolution symmetry.

A system to integrate microwave imaging with optical colonoscopy is presented. The overarching goal is to improve the prevention, diagnosis and understanding of one of the main health and economic burdens of an increasingly ageing population that is colorectal cancer. Our system can address the two main challenges of colonoscopy – improve the detection of precancerous lesions called polyps and classify them according to their malignancy – and moves forward a major trend of the field that is automating medical explorations. To do so, a complete imaging system able to emit an alarm when a polyp is detected is designed, manufactured and validated with a realistic colon phantom composed by tissue-mimicking oil-gelatin materials reproducing the anatomy and dielectric properties of a human colon with a polyp. The acquisition is done by a miniaturized ring-shaped switched array of 16 antennas attachable at the tip of a conventional colonoscope. It has been conceived to satisfy endoscopy si...

This study assesses the efficacy of detecting colorectal cancer precursors or polyps in an ex vivo human colon model with a microwave colonoscopy algorithm. Nowadays, 22% of polyps go undetected with conventional colonoscopy, and the risk of cancer after a negative colonoscopy can be up to 7.9%. We developed a microwave colonoscopy device that consists of a cylindrical ring-shaped switchable microwave antenna array that can be attached to the tip of a conventional colonoscope as an accessory. The accessory is connected to an external unit that allows successive measurements of the colon and processes the measurements with a microwave imaging algorithm. An acoustic signal is generated when a polyp is detected. Fifteen ex vivo freshly excised human colons with cancer (n = 12) or polyps (n = 3) were examined with the microwave-assisted colonoscopy system simulating a real colonoscopy exploration. After the experiment, the dielectric properties of the specimens were measured with a coax...

Introduction. Microwave imaging can obtain 360° anatomical and functional images of the colon representing the existing contrast in dielectric properties between different tissues. Microwaves are safe (nonionizing) and have the potential of reducing the visualization problems of conventional colonoscopy. This study assessed the efficacy of a microwave-based colonoscopy device to detect neoplastic lesions in an ex vivo human colon model. Methods. Fresh surgically excised colorectal specimens containing cancer or polyps were fixed to a 3D positioning system, and the accessory device was introduced horizontally inside the ex vivo colon lumen and moved along it simulating a real colonoscopy exploration. Measurements of the colon were taken every 4 mm with the microwave-based colonoscopy device and processed with a microwave imaging algorithm. Results. 14 ex vivo human colorectal specimens with carcinomas ( n = 11 ) or adenomas with high grade dysplasia ( n = 3 ) were examined with a mic...

In this paper a complete UWB Circular Tomographic System robust to high contrast or large objects, applied to Breast Tumor Detection, is presented. The main contribution of this paper is to focus on the implementation of a two degrees of freedom imaging setup in order to deal with non-symmetric objects and to demonstrate its functionality with realistic breast phantoms.