Design of a Thin Film Infrared Barcode on a Flexible Substrate

We report the design, fabrication and characterization of an infrared barcode. This barcode is composed of a bilayer of titanium and amorphous silicon on a flexible Kapton substrate. Information encoded in the barcode shows high contrast when viewed with an infrared imaging system in the 8 to 12 μm spectral region. The barcode information is concealed under visible viewing conditions, i.e., the barcode appears as an untreated, uniform metal sheet to a detector of visible radiation (400 to 700nm).     

Multi levels semantic architecture for multimodal interaction

This paper presents a semantic architecture for solving multimodal interaction. Our architecture is based on multi agent systems where agents are purely semantic using ontologies and inference system. Multi levels concepts and behavioural models are taken into account to bring a fast high level reasoning on a big amount of percepts and low level actions. We apply this architecture to make a system aware of different situations in a network like tracking object behaviours of the environment. As a proof of concept, we apply our architecture to an assistant robot helping blind or disabled people to cross a road in a virtual reality environment.     

Optical resonances in periodic surface arrays of metallic patches

The transmission of light along the surface normal through an air-quartz-glass interface covered with a periodic array of thin, rectangular gold patches has been studied over the visible to infrared range. The various structures that are observed can be qualitatively understood as arising from standing-wave resonances set by the size and surroundings of the metal patches. A method-of-moments calculational scheme provides simulations in good quantitative agreement with the data. It is shown how the standing-wave picture provides a useful conceptual framework to understand and exploit such systems.     

Assessment of wheelchair skills based on analysis of driving style

In this paper, we propose a learning assessment method based on the analysis of learner’s behavioural style. This method was first applied for wheel-chair driving tasks because it is simple and risk-free, but unusual for users. Seven classic performance indicators based on joystick control were used to characterise the users’ driving style. We assumed that the learning effectiveness of the users can be evaluated by comparing their driving style with the reference ones, which could be extracted from experienced users. The evaluation was carried out for six novice users and eight experienced users. The users were asked to carry out several typical driving tasks for seven trials at first. The fuzzy C-means clustering method was used with the data of the experienced users to obtain the reference driving styles. Next, an evaluation was performed for novice users by comparing their driving styles with the reference ones. The results showed that, for all of the experienced users, their driving styles could be classified into two reference types. In addition, there was no significant difference in their driving styles from one trial to another, even for a user with disabilities, which means that their driving style was stable. On the other hand, novice users had switching behaviours during the learning phase; however, after eight additional trials, each novice user’s driving style converged to one of the two identified reference types, meaning that the novice users could achieve a stable performance after learning, which was also validated by an expert therapist.     

Infrared frequency selective surface based on circuit-analog square loop design

A frequency selective surface (FSS) was designed to have a resonant spectral signature in the infrared. The lithographically composed, layered structure of this infrared FSS yields a resonant response in absorption to infrared radiation at a wavelength determined by its FSS element structure and the structure of its substrate layers. The infrared spectral characteristics of this surface are studied via Fourier transform infrared spectroscopy and spectral radiometry in the 3 to 15 /spl mu/m region of the spectrum. The design is based on circuit-analog resonant behavior of square loop conducting elements.     

Structural Alterations of Human Serum Albumin Caused by Glycative and Oxidative Stressors Revealed by Circular Dichroism Analysis

The aim of this work was to evaluate the ability of oxidative and glycative stressors to modify properties of human serum albumin (HSA) by analyzing markers of glycation (pentosidine) and oxidation (advanced oxidative protein products (AOPPs)) and assessing fluorescence and circular dichroism. HSA was incubated for up to 21 days with ribose, ascorbic acid (AA) and diethylenetriamine pentacetate (DTPA) in various combinations in order to evaluate influences of these substances on the structure of HSA. Ribose was included as a strong glycative molecule, AA as a modulator of oxidative stress, and DTPA as an inhibitor of metal-catalyzed oxidation. Ribose induced a significant increase in pentosidine levels. AA and DTPA prevented the accumulation of pentosidine, especially at later time points. Ribose induced a mild increase in AOPP formation, while AA was a strong inducer of AOPP formation. Ribose, in combination with AA, further increased the formation of AOPP. DTPA prevented the AA-induced generation of AOPP. Ribose was also a potent inducer of fluorescence at 335nm ex/385nm em, which is typical of pentosidine. AA and DTPA prevented this fluorescence. Circular dichroism showed complex results, in which AA and DTPA were strong modifiers of the percentages of the alpha-helical structure of HSA, while ribose affected the structure of HSA only at later time points.     

Fault localization in data networks

In this letter we show a fault localization system implemented by using policy-based thresholds for triggering alarms or self-healing mechanisms. Alarms are collected and organized within a codebook, which is a fundamental component of our fault management system. The relevant performance is analyzed by using a real network deploying VoIP services.     

Uncertainty analysis in the measurement of the spatial responsivity of infrared antennas

The measurement of a two-dimensional spatial responsivity map of infrared antennas can be accomplished by use of an iterative deconvolution algorithm. The inputs of this algorithm are the spatial distribution of the laser beam irradiance illuminating the antenna-coupled detector and a map of the measured detector response as it moves through the illuminating beam. The beam irradiance distribution is obtained from knife-edge measurements of the beam waist region; this data set is fitted to a model of the beam. The uncertainties, errors, and artifacts of the measurement procedure are analyzed by principal-component analysis. This study has made it possible to refine the measurement protocol and to identify, classify, and filter undesirable sources of noise. The iterative deconvolution algorithm stops when a well-defined threshold is reached. Spatial maps of mean values and uncertainties have been obtained for the beam irradiance distribution, the scanned spatial response data, and the resultant spatial responsivity of the infrared antenna. Signal-to-noise ratios have been defined and compared, and the beam irradiance distribution characterization has been identified as the statistically weakest part of the measurement procedure.