Evaluating maps produced by urban search and rescue robots: lessons learned from RoboCup

This paper presents the map evaluation methodology developed for the Virtual Robots Rescue competition held as part of RoboCup. The procedure aims to evaluate the quality of maps produced by multi-robot systems with respect to a number of factors, including usability, exploration, annotation and other aspects relevant to robots and first responders. In addition to the design choices, we illustrate practical examples of maps and scores coming from the latest RoboCup contest, outlining strengths and weaknesses of our modus operandi. We also show how a benchmarking methodology developed for a simulation testbed effortlessly and faithfully transfers to maps built by a real robot. A number of conclusions may be derived from the experience reported in this paper and a thorough discussion is offered.     

Reduced specificity of autobiographical memory in Cluster C personality disorders and the role of depression, worry, and experiential avoidance.

The study objective was to investigate whether, compared with nonclinical controls, participants with an avoidant, dependent, or obsessive–compulsive Cluster C personality disorder (PD) manifested reduced levels of memory specificity and whether the association of Cluster C PDs with memory specificity is mediated by repetitive negative thoughts and experiential avoidance. The Autobiographical Memory Test (R. J. McNally, N. B. Lasko, M. L. Macklin, & R. K. Pitman, 1995) was administered along with self-report measures (translated into Dutch) for repetitive, uncontrollable, and negative thinking in the form of worry (Penn State Worry Questionnaire; T. J. Meyer, M. L. Miller, R. L. Metzger, & T. D. Borkovec, 1990) and experiential avoidance (Acceptance and Action Questionnaire; S. C. Hayes et al., 2004) to 294 clinical participants diagnosed with Axis I disorders (assessed with the Structured Clinical Interview for DSM–IV Axis I Disorders [SCID-I]; M. B. First, R. L. Spitzer, M. Gibbon, & J. B. W. Williams, 1994) and Axis II disorders (assessed with the SCID-II; M. B. First, R. L. Spitzer, M. Gibbon, & J. B. W. Williams, 1997)—202 with avoidant, 49 with dependent, and 120 with obsessive–compulsive PD—and to 108 matched nonclinical controls. Participants with a Cluster C PD showed lower levels of memory specificity than did nonclinical controls. Depression and worry mediated the effect of Cluster C PDs on memory specificity. Besides depression severity, repetitive, uncontrollable, and negative thinking may constitute a general mechanism mediating the association of various Axis I and II disorders with memory specificity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Covariation detection in treated and untreated spider phobics.

20 treated and 18 untreated spider phobics were exposed to a series of 72 slides. Three different categories of slides were used: phobia-relevant slides (spiders), alternative fear-relevant slides (weapons), and neutral slides (flowers). Slides were randomly paired with either a shock, a tone, or nothing at all. Despite the absence of a systematic correlation between slides and outcomes, untreated phobics strongly overestimated the covariation between spider slides and shock. Treated phobics did not show a covariation bias, suggesting that such bias can be modulated by the behavioral treatment. In addition, untreated Ss were more confident about their contingency estimates than were treated Ss. The present results fit with earlier studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Food packaging simulant failure mechanisms in next generation steel packaging

Legislative pressures have led to the mature dominant chromium‐coated steel (ECCS) substrate and epoxy phenolic lacquer replacement in Europe. An investigation was carried out to examine the interaction between a steel surface engineered with a novel, developmental substrate coated using Cr (III)‐based electrolytes and the food stuff being canned. Samples of lacquered material were subjected to a typical retort process (121°C for 90 minutes) and examined using a variety of laboratory analytical techniques. The foodstuff being packaged has a significant impact on the substrate/lacquer adhesion with clear differences in failure mechanisms between foodstuffs. There is clear evidence of chemical species transfer through the next generation lacquer, and this can instigate corrosion at the surface where incomplete chromium coverage leads to exposed iron. In general, the novel developmental material exhibits lower adhesive properties and shows a greater sensitivity to the foodstuff, although this is largely attributed to the homogeneity of the coverage. The novel substrate proves to be a promising alternative to ECCS due to REACH legislation, but improvement is required to achieve equivalent performance.     

Understanding the Role of Ferroelastic Domains on the Pyroelectric and Electrocaloric Effects in Ferroelectric Thin Films

Temperature‐ and electric‐field‐induced structural transitions in a polydomain ferroelectric can have profound effects on its electrothermal susceptibilities. Here, the role of such ferroelastic domains on the pyroelectric and electrocaloric response is experimentally investigated in thin films of the tetragonal ferroelectric PbZr_0.2Ti_0.8O₃. By utilizing epitaxial strain, a rich set of ferroelastic polydomain states spanning a broad thermodynamic phase space are stabilized. Using temperature‐dependent scanning‐probe microscopy, X‐ray diffraction, and high‐frequency phase‐sensitive pyroelectric measurements, the propensity of domains to reconfigure under a temperature perturbation is quantitatively studied. In turn, the “extrinsic” contributions to pyroelectricity exclusively due to changes between the ferroelastic domain population is elucidated as a function of epitaxial strain. Further, using highly sensitive thin‐film resistive thermometry, direct electrocaloric temperature changes are measured on these polydomain thin films for the first time. The results demonstrate that temperature‐ and electric‐field‐driven domain interconversion under compressive strain diminish both the pyroelectric and the electrocaloric effects, while both these susceptibilities are enhanced due to the exact‐opposite effect from the extrinsic contributions under tensile strain.     

Low-Frequency Noise Phenomena in Switched MOSFETs

In small-area MOSFETs widely used in analog and RF circuit design, low-frequency (LF) noise behavior is increasingly dominated by single-electron effects. In this paper, the authors review the limitations of current compact noise models which do not model such single-electron effects. The authors present measurement results that illustrate typical LF noise behavior in small-area MOSFETs, and a model based on Shockley-Read-Hall statistics to explain the behavior. Finally, the authors treat practical examples that illustrate the relevance of these effects to analog circuit design. To the analog circuit designer, awareness of these single-electron noise phenomena is crucial if optimal circuits are to be designed, especially since the effects can aid in low-noise circuit design if used properly, while they may be detrimental to performance if inadvertently applied     

Identifying interlayer surface adhesion failure mechanisms in tinplate packaging steels

Tinplate surface morphology and chemistry is adjusted during the manufacturing process in order to meet the demands of its subsequent product use, the commonest being visual appearance and food packaging stability. A comprehensive experimental study on an industrial tinning line varied the surface roughness and the tin coating weight with the characterization through X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), white light interferometer (WLI), optical imaging, and lacquer adhesion measurement. Increasing tin weight lowers the adhesion through the production of a thicker disorganized tin oxide layer which has a greater tendency to fracture under shearing forces. There is no evidence that the substrate roughness improves the adhesion of the lacquer. Analysis of the failure location identifies fracture in the tin oxide layer below the passivation layer. The findings have impacts on the next generation of passivation materials for tinplate as it has been clearly demonstrated that growth in tin oxide thickness, particularly when unstructured, has a detrimental impact on lacquer adhesion.     

Exploring the Arabidopsis Proteome: Influence of Protein Solubilization Buffers on Proteome Coverage

The study of proteomes provides new insights into stimulus-specific responses of protein synthesis and turnover, and the role of post-translational modifications at the systems level. Due to the diverse chemical nature of proteins and shortcomings in the analytical techniques used in their study, only a partial display of the proteome is achieved in any study, and this holds particularly true for plant proteomes. Here we show that different solubilization and separation methods have profound effects on the resulting proteome. In particular, we observed that the type of detergents employed in the solubilization buffer preferentially enriches proteins in different functional categories. These include proteins with a role in signaling, transport, response to temperature stimuli and metabolism. This data may offer a functional bias on comparative analysis studies. In order to obtain a broader coverage, we propose a two-step solubilization protocol with first a detergent-free buffer and then a second step utilizing a combination of two detergents to solubilize proteins.     

Salivary biomarkers associated with perceived satiety and body mass in humans

Regulation of food intake and energy homeostasis is controlled by a delicate balancing of numerous central and peripheral factors, including circulating peptide hormones. This study investigated the proteome of saliva using SELDI‐TOF‐MS in relation to satiety and body mass index (BMI) in humans. Within a longitudinal test session, 18 subjects were exposed to a lunch‐induced hunger‐satiety shift, while every 15 min collecting their whole saliva and rating their hunger and satiety. Saliva was analysed by SELDI‐TOF‐MS using IMAC arrays with a chromatographic copper surface (IMAC‐Cu). From all subjects and time points measured, peptide and protein profiles showed 190 common peaks. Their interrelationships show that 37% of the variation was accounted for in one dimension. About 30 means had a strong association (0.70<|r|<0.95) with all subjective satiety ratings across time during the test session, and seven peaks were significantly correlated to BMI. Database MS searches indicated characterisation of some relevant metabolic peptide hormones. In conclusion, SELDI‐TOF‐MS on human saliva provides a valuable and noninvasive way of profiling that enables characterisation of novel and differently expressed peptides and proteins which can be used as biomarkers of satiety and overweight.