An alternative control structure for telerobotics

A new teletobotic control concept which couples human supervisory commands with computer reasoning is presented. The control system is responsive and accomplishes an operator's commands while providing obstacle avoidance and stable controlled interactions with the environment in the presence of communication time delays. This provides a system which not only assists the operator in accomplishing tasks but modifies inappropriate operator commands which can result in safety hazards and/or equipment damage

A meteorological overview of the ARCTAS 2008 mission

The <i>A</i>rctic <i>R</i>esearch of the <i>C</i>omposition of the <i>T</i>roposphere from <i>A</i>ircraft and <i>S</i>atellites (ARCTAS) mission was a multi-aircraft project whose major objective was to investigate the factors driving changes in the Arctic's atmospheric composition and climate. It was conducted during April and June–July 2008. The summer ARCTAS deployment was preceded by a week of flights over and around California to address state issues of air quality and climate forcing. This paper focuses on meteorological conditions during the ARCTAS Spring and Summer campaigns. We examine mission averaged large-scale flow patterns at the surface, 500 hPa, and 300 hPa and determine their departures from climatology. Results from runs of the <i>W</i>eather <i>R</i>esearch and <i>F</i>orecasting (WRF) model are used to describe meteorological conditions on individual days. Our WRF configuration included a nested grid approach that provided horizontal spacing as small as 5 km. Trajectories calculated from the WRF output are used to determine transport pathways to the Arctic, including their origins and the altitudes at which they reach 70° N. We also present backward trajectories from selected legs of individual ARCTAS flights. Finally, the FLEXPART Lagrangian particle dispersion model, with the high resolution WRF data as input, is used to determine the paths of anthropogenic and biomass burning-derived CO. Results show that there was frequent and widespread transport to the Arctic during both phases of ARCTAS and that the three ARCTAS aircraft sampled air having a multitude of origins, following a myriad of paths, and experiencing many types of meteorological conditions

Nindestructive Evaluation of Metal Matrix Composite Products with Implanted Defects

The Westinghouse Science and Technology Center has undertaken a program to develop nondestructive evaluation (NDE) techniques for characterizing the internal structure of SiC particle-reinforced aluminum matrix composites at critical stages during fabrication [1–5]. Because of the large number of processing variables in the manufacture of metal matrix composites (MMC), the likelihood of having detrimental discontinuities is high. The detection of potential defects early in the processing cycle would increase the overall system yield, lower costs, and enhance final product quality [4]. The aim of this investigation was to develop and conduct NDE at various stages of MMC fabrication, correlate the results with microstructural characterization, and establish qualified product quality assurance processes. A large-scale billet was fabricated specially using powder metallurgy techniques to facilitate this objective. The billet contained implanted silicon-carbide particle and aluminum powder clusters as inspection targets. The billet was subsequently extruded into a primary cylindrical extrusion, and finally into a flat plate. The NDE objectives included evaluating the detectability and mapping the implanted defects through each of the processing steps. Comprehensive evaluation of MMC structures requires the use of multiple NDE techniques, including ultrasonic, eddy current, and radiographic testing. This paper concentrates on the results of the ultrasonic investigations. Our experimental approach was: (1) fabricate a MMC billet with intentionally placed inhomogeneities; (2) develop and implement NDE techniques to characterize the MMC internal structure; (3) extend the NDE techniques to intermediate processing and final product forms; and (4) correlate the NDE data with microstructural characterization and mechanical testing results

Intelligent automated control of robotic systems for environmental restoration

The US Department of Energy`s Office of Technology Development (OTD) has sponsored the development of the Generic Intelligent System Controller (GISC) for application to remote system control. Of primary interest to the OTD is the development of technologies which result in faster, safer, and cheaper cleanup of hazardous waste sites than possible using conventional approaches. The objective of the GISC development project is to support these goals by developing a modular robotics control approach which reduces the time and cost of development by allowing reuse of control system software and uses computer models to improve the safety of remote site cleanup while reducing the time and life cycle costs

The Universe is not a Computer

When we want to predict the future, we compute it from what we know about the present. Specifically, we take a mathematical representation of observed reality, plug it into some dynamical equations, and then map the time-evolved result back to real-world predictions. But while this computational process can tell us what we want to know, we have taken this procedure too literally, implicitly assuming that the universe must compute itself in the same manner. Physical theories that do not follow this computational framework are deemed illogical, right from the start. But this anthropocentric assumption has steered our physical models into an impossible corner, primarily because of quantum phenomena. Meanwhile, we have not been exploring other models in which the universe is not so limited. In fact, some of these alternate models already have a well-established importance, but are thought to be mathematical tricks without physical significance. This essay argues that only by dropping our assumption that the universe is a computer can we fully develop such models, explain quantum phenomena, and understand the workings of our universe. (This essay was awarded third prize in the 2012 FQXi essay contest; a new afterword compares and contrasts this essay with Robert Spekkens' first prize entry.)Comment: 10 pages with new afterword; matches published versio

Osjetljivost na vlagu te optička, mehanička i strukturna svojstva jestivih filmova na bazi proteina sirutke s dodatkom repičinog ulja

The objective of this work is to study the effect of the rapeseed oil content on the physical properties of whey protein emulsion films. For this purpose, whey protein films with the addition of 0, 1, 2 and 3 % of rapeseed oil, and glycerol as a plasticizer were obtained by the casting method. Film-forming emulsions were evaluated and compared using light scattering granulometry. The Sauter mean diameters (d32) of lipid droplets in film-forming solutions showed an increasing trend when increasing the oil volume fractions. The inclusion of rapeseed oil enhanced the hydrophobic character of whey protein films, reducing moisture content and film solubility in water. All emulsified films showed high lightness (L*≈90). Parameter a* decreased and parameter b* and total colour difference (ΔE) increased with the increase of the volume fractions of oil. These results were consistent with visual observations; control films were transparent and those containing oil opaque. Water vapour sorption experimental data at the full range of water activity values from 0.11 to 0.93 were well described with Peleg’s equation (R2≥0.99). The tensile strength, Young’s modulus and elongation at break increased with the increase of rapeseed oil volume fraction, which could be explained by interactions between lipids and the protein matrix. These results revealed that rapeseed oil has enormous potential to be incorporated into whey protein to make edible film or coating for some food products. The mechanical resistance decreased with the addition of the lipids, and the opacity and soluble matter content increased.Svrha je ovoga rada bila ispitati utjecaj dodatka repičinog ulja u različitim volumnim udjelima na fizikalna svojstva filmova izrađenih od proteina sirutke. Filmovi su pripremljeni u kalupima lijevanjem emulzija dobivenih od proteina sirutke s dodatkom 0, 1, 2 ili 3 % repičinog ulja te glicerola kao plastifikatora. Raspodjela veličine čestica emulzije određena je metodom laserske difrakcije, te je utvrđeno da se s povećanjem volumnog udjela ulja povećao srednji Sauterov promjer (d32) lipidnih kapljica. Dodatkom repičinog ulja povećala se hidrofobnost, a smanjio udjel vlage u filmovima te njihova topljivost u vodi. Sve su emulzije bile vrlo svijetle (L*≈90), a pri većim volumnim udjelima ulja smanjila se vrijednost parametra a*, a povećali vrijednost parametra b* i ukupna razlika u boji (ΔE). Rezultati su bili u skladu s onima dobivenim vizualnim pregledom: kontrolni uzorci filmova bili su prozirni, dok su oni s dodatkom ulja bili mutni. Ispitana je sposobnost upijanja vode filmova, a dobiveni su podaci u rasponu aktiviteta vode od 0,11 do 0,93 dobro opisani pomoću Pelegove jednadžbe (R2≥0,99). Povećanjem volumnog udjela repičinog ulja povećali su se vlačna čvrstoća, Youngov modul elastičnosti i istezljivost filmova, vjerojatno uslijed povezivanja lipida s proteinima. Rezultati pokazuju da se dodavanjem repičinog ulja emulzijama dobivenim od proteina sirutke može proizvesti jestivi film ili omotač za koje postoji velika mogućnost primjene u prehrambenoj industriji. Dodatkom lipida smanjili su se mehanički otpor i prozirnost filmova, a povećao udjel topljivih tvari

Extreme multi-basin flooding linked with extra-tropical cyclones [Poster]

Fluvial floods are typically investigated as ‘events’ at the single basin-scale, hence flood management authorities may underestimate the threat of flooding across multiple basins driven by large-scale and nearly concurrent atmospheric event(s). We pilot a national-scale statistical analysis of the spatio-temporal characteristics of extreme multi-basin flooding (MBF) episodes, using peak river flow data for 260 basins in Great Britain (1975-2014), a sentinel region for storms impacting northwest and central Europe. During the most widespread MBF episode, 108 basins (~46% of the study area) recorded Annual Maximum (AMAX) discharge within a 16-day window. Such episodes are associated with persistent cyclonic and westerly atmospheric circulations, atmospheric rivers, and precipitation falling onto previously saturated ground, leading to hydrological response times <40h and documented flood impacts. Furthermore, peak flows tend to occur after 0-13 days of very severe gales causing combined and spatially-distributed, yet differentially time-lagged, wind and flood damages. These findings have implications for emergency responders, insurers and contingency planners worldwide

Improving treatment and survival: a population‐based study of current outcomes after a hepatic resection in patients with metastatic colorectal cancer

AbstractBackgroundPopulation‐based studies historically report underutilization of a resection in patients with colorectal metastases to the liver. Recent data suggest limitations of the methods in the historical analysis. The present study examines trends in a hepatic resection and survival among Medicare recipients with hepatic metastases.MethodsMedicare recipients with incident colorectal cancer diagnosed between 1991 and 2009 were identified in the SEER(Surveillance, Epidemiology and End Results)‐Medicare dataset. Patients were stratified into historical (1991–2001) and current (2002–2009) cohorts. Analyses compared treatment, peri‐operative outcomes and survival.ResultsOf 31 574 patients with metastatic colorectal cancer to the liver, 14 859 were in the current cohort treated after 2002 and 16 715 comprised the historical control group. The overall proportion treated with a hepatic resection increased significantly during the study period (P< 0.001) with pre/post change from 6.5% pre‐2002 to 7.5% currently (P < 0.001). Over time, haemorrhagic and infectious complications declined (both P ≤ 0.047), but 30‐day mortality was similar (3.5% versus 3.9%, P = 0.660). After adjusting for predictors of survival, the use of a hepatic resection [hazard ratio (HR) = 0.40, 95% confidence interval (CI): 0.38–0.42, P < 0.001] and treatment after 2002 (HR = 0.88, 95% CI: 0.86–0.90, P < 0.001) were associated with a reduced risk of death.ConclusionsCase identification using International Classification of Diseases, 9th Revision (ICD‐9) codes is imperfect; however, comparison of trends over time suggests an improvement in multimodality therapy and survival in patients with colorectal metastases to the liver