Handling causality and schedulability when designing and prototyping cyber-physical systems

Software and Systems Modeling - Cyber physical systems are built upon digital and analog circuits, making it necessary to handle different models of computation during their design and verification...     

Photocatalytic degradation of a phenylurea, chlortoluron, in water using an industrial titanium dioxide coated media

The degradation of an herbicide, chlortoluron, by UV/TiO₂ photocatalysis in water using industrial titanium dioxide coated non-woven paper was studied. The influence of parameters such as adsorption capacity, initial concentration and TiO₂ implementation (coated or in suspension) was investigated. The results emphasize the importance of operational conditions and reactor geometry on the kinetic degradation rate. The analysis of the first organic by-products suggests that a hydroxyl radical attack occurs on the phenyl ring and methyl groups of the chlortoluron before the opening of the aromatic ring. The fate of hetero-atoms has been investigated. The fates of the two nitrogen atoms in the molecule are different, not only did it depend on their initial oxidation degree, as both had the same oxidation degree, but also on the initial oxidation state of neighboring carbons. The chlorine atoms were completely released as chloride ions. The study of the influence of the oxygen concentration showed the importance of the oxygen mass transfer when designing an industrial photocatalytic reactor. An original calculation process was carried out to evaluate the adsorption constant of oxygen over the whole photocatalysis period and not only in the initial conditions as previously provided. This work points out the necessity of extending the understanding of the efficiency of chlortoluron removal or of the removal of various complex pesticide mixtures found in agricultural wastewater, using alternative, more industrially realistic, reactors.     

Enhancement of gain and radiation bandwidth for a planar 1-D EBG antenna

This letter describes a technique to increase the radiation bandwidth and the gain of a classical planar electromagnetic band gap (EBG) antenna. Those two parameters are relative to the EBG material but also to the excitation, this second characteristic is studied here. The principle is to excite the EBG structure with several sources (instead of a single one classically). The performances depend on the number of sources and their spacing. Directivity and radiation bandwidth can be increased dramatically with few sources.     

Reconstructing the 3D shape and bone mineral density distribution of the proximal femur from dual-energy X-ray absorptiometry

The accurate diagnosis of osteoporosis has gained increasing importance due to the aging of our society. Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is an established criterion in the diagnosis of osteoporosis. This measure, however, is limited by its two-dimensionality. This work presents a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image used in clinical routine. A statistical model of the combined shape and BMD distribution is presented, together with a method for its construction from a set of quantitative computed tomography (QCT) scans. A reconstruction is acquired in an intensity based 3D-2D registration process whereby an instance of the model is found that maximizes the similarity between its projection and the DXA image. Reconstruction experiments were performed on the DXA images of 30 subjects, with a model constructed from a database of QCT scans of 85 subjects. The accuracy was evaluated by comparing the reconstructions with the same subject QCT scans. The method presented here can potentially improve the diagnosis of osteoporosis and fracture risk assessment from the low radiation dose and low cost DXA devices currently used in clinical routine.     

Sine-Wave Signal Characterization Using Square-Wave and ΣΔ-Modulation: Application to Mixed-Signal BIST

This paper presents a method for extracting, in the digital domain, the main characteristic parameters of an analog sine-wave signal. It is based on a double-modulation, square-wave and sigma-delta, together with a simple Digital Processing Algorithm. It leads to an efficient and robust approach very suitable for BIST applications. In this line, some considerations for on-chip implementation are addressed together with simulation results that validate the feasibility of the proposed approach.Diego Vázquez was born in El Coronil, Sevilla, Spain, in 1966. He received the Licenciado en Física degree in 1989 and the Doctor en Ciencias Físicas degree in 1995, both from the University of Sevilla, Spain. Since 1990, he has been with the Departamento de Electrónica y Electromagnetismo, University of Sevilla, where he is a Associate Professor, and also with the Instituto de Microelectrónica de Sevilla, Centro Nacional de Microelectrónica (IMSE-CNM-CSIC), Sevilla, Spain. He has published about 100 papers in international journals, books and major conferences. In 1992 he won the Best Paper Award of the 10th IEEE VLSI Test Symposium. His research interests are in the fields of design, fault tolerance, test, and design for testability of analog and mixed-signal circuits.Gloria Huertas was born in Sevilla, Spain, in 1974. She received the Licenciado en Física degree in 1997 and the Ph.D. in 2004, both from the University of Sevilla, Spain. Since then, she has been with the Departamento de Electrónica y Electromagnetismo, University of Sevilla, where she is Assistant Professor, and also with the Instituto de Microelectrónica de Sevilla, Centro Nacional de Microelectrónica (IMSE-CNM-CSIC), Sevilla, Spain. Her research focuses on designing electronic mixed-signal circuits and systems including techniques for testability.África Luque was born in Zamora (Spain) in 1977. She received the Licenciado en Física degree in 2000 from the University of Sevilla, Sevilla, Spain. She is with the Departamento de Electrónica y Electromagnetismo, University of Sevilla, and also with the Instituto de Microelectrónica de Sevilla, Centro Nacional de Microelectrónica (IMSE-CNM-CSIC), Sevilla, Spain, where she is currently pursuing the Ph.D. degree. Her research focuses on the design and test of mixed-signal circuits including Silicon-On-Insulator technologies.Manuel J. Barragan was born in Sevilla, Spain, in 1980. He received the Licenciado en Física degree in 2003 from the University of Sevilla, Sevilla, Spain. He is currently pursuing the Ph.D. degree from the Instituto de Microelectrónica de Sevilla (IMSE, CNM) on the topics of test and design for testability of analog and mixed-signal circuits.Gildas Leger was born in St. Brieuc, Côtes dArmor, France, in 1976. He received the Ingénieur en Physique degree in 1999 from the National Institute of Applied Sciences (INSA) of Rennes, France.He is currently pursuing the Ph.D. degree from the Instituto de Microelectrónica de Sevilla (IMSE, CNM). His research focuses on designing electronic mixed-signal circuits and systems including techniques for testability, specially in the domain of analog to digital conversion.Adoración Rueda joined the Department of Electronics and Electromagnetism at the University of Seville in 1976 as Assistant Professor, and obtained the Ph.D. degree in 1982. From 1984 to 1996 she was Associate Professor in that Department, where now holds the position of Full Professor in Electronics. In 1989 she became researcher at the Department of Analog Design of the National Microelectronics Center (CNM), now Institute of Microelectronics at Seville (IMSE).She has participated in several research projects financed by the Spanish CICYT and by different programs of the European Community. She has published about 135 papers in international journals, books and major conferences. In 1992 she won the Best Paper Award of the 10th IEEE VLSI Test Symposium. Her research interests are currently focused on the topics of Design and Test of Analog and Mixed-signal Circuits, Behavioral Modeling of Mixed-signal Circuits, and development of CAD tools.Jose Luis Huertas received the Licenciado en Física degree nd the Doctor en Ciencias Físicas degrees in 1969 and 1973, respectively, both from the University of Sevilla, Spain.From 1970 to 1971, he was with the Philips International Institute, Eindhoven, The Netherlands, as a postgraduate student. Since 1971, he has been with the Departamento de Electrónica y Electromagnetismo, University of Sevilla, Spain, where he is a Full Professor. He is also the Director of the Instituto de Microelectrónica de Sevilla, Centro Nacional de Microelectrónica de Sevilla, Seville, Spain. His current interests include the design and testing of analog/digital integrated circuits, computer-aided IC analysis and design, fuzzy logic, nonlinear microelectronics, and neural networks.     

Un environnement de conception de systèmes distribués basé sur UML

This paper introduces a new environment for developing distributed systems. It is based on theTurtle uml profile. Analysis and design phases, described in previous papers, have been extended with an additional deployment phase. In this new step,Turtle components are deployed over hardware execution nodes, and nodes are connected together throughout links,Turtle deployment diagrams are given a formal semantics inRt-lotos, therefore following the approach used forTurtle analysis and design diagrams. Moreover, the paper presents a Java code generator which outputs appropriate Java code forTurtle deployment diagrams. This code is automatically deployable on networks because it implements node communication using network protocols such asUdp orRmi. ttool, the turtle toolkit has been extended to support these new diagrams and code generators. The attack of protected data exchanged throughout securedHttp sessions serves as example.     

Behavioural models for distributed Fractal components

This paper presents a formal behavioural specification framework for specifying and verifying the correct behaviour of distributed Fractal components. The first contribution is a parameterised and hierarchical behavioural model called pNets that serves as a low-level semantic framework for expressing the behaviour of various classes of distributed languages and as a common internal format for our tools. Then, we use this model to define the generation of behavioural models for applications ranging from sequential Fractal components, to distributed objects, and finally to distributed components. Our models are able to characterise both functional and non-functional behaviours and the interaction between the two concerns. Finally, this work has resulted in the development of tools allowing the non-expert programmer to specify the behaviour of his components and (semi)automatically verify properties of his application.     

Enhanced Spectral Mode Selection in an Aspheric Extended-Cavity Resonator

Strong spectral-mode-selection behavior has been observed in a three-mirror solid-state resonator that was constructed by colinearly aligning an aspheric feedback mirror with a standing-wave two-mirror resonator. This spectral mode selection is measured to be much stronger than that predicted by the frequency selection theory of simple Fabry-Perot cavities. Our study shows that the spatial modes and their associated eigenvalues vary at different oscillation wavelengths in a complex extended-cavity resonator. It is the interplay between spatial modes and spectral modes that induces the strong spectral-mode selection     

Highly Conductive Poly(3,4‐ethylenedioxythiophene):Poly (styrenesulfonate) Films Using 1‐Ethyl‐3‐methylimidazolium Tetracyanoborate Ionic Liquid

Highly conductive poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films are obtained using ionic liquids as additives. Upon adding 1‐ethyl‐3‐methylimidazolium tetracyanoborate (EMIM TCB) to the conducting polymer, the conductivity increases to 2084 S cm^?1; this is attributed to the phase separation of PSS leading to a structural change in the film. A comparative study with 1‐butyl‐3‐methyl imidazolium tetrafluoroborate (BMIM BF₄) shows that EMIM TCB gives higher conductivity and transmittance and can be regarded as one of the most promising additives for the preparation of indium tin oxide (ITO)‐free organic devices using PEDOT:PSS/EMIM TCB as electrodes.     

Biocompatible Electromechanical Actuators Composed of Silk‐Conducting Polymer Composites

Single‐component, metal‐free, biocompatible, electromechanical actuator devices are fabricated using a composite material composed of silk fibroin and poly(pyrrole) (PPy). Chemical modification techniques are developed to produce free‐standing films with a bilayer‐type structure, with unmodified silk on one side and an interpenetrating network (IPN) of silk and PPy on the other. The IPN formed between the silk and PPy prohibits delamination, resulting in a durable and fully biocompatible device. The electrochemical stability of these materials is investigated through cyclic voltammetry, and redox sensitivity to the presence of different anions is noted. Free‐end bending actuation performance and force generation within silk‐PPy composite films during oxidation and reduction in a biologically relevant environment are investigated in detail. These silk–PPy composites are stable to repeated actuation, and are able to generate forces comparable with natural muscle (>0.1 MPa), making them ideal candidates for interfacing with biological tissues.