2,048 research outputs found

    Teleworkbench: An Analysis Tool for Multi-Robotic Experiments

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    Tanoto A, Du JL, Witkowski U, Rückert U. Teleworkbench: An Analysis Tool for Multi-Robotic Experiments. In: Proceedings of the IFIP Conference on Biologically Inspired Cooperative Computing (BICC 2006), 19th World Computer Congress (WCC). Santiago, Chile; 2006.This paper presents a tool, one component of the Teleworkbench system, for analyzing experiments in multi-robotics. The proposed tool combines the video taken by a web cam monitoring the field where the experiment runs and some computer generated visual objects representing important events and information as well as robots’ behavior into one interactive video based on MPEG-4 standard. Visualization and data summarization enables the developer to quickly grasp a situation, whereas the possibility of scrolling through the video and selectively activating information helps him analyzing interesting events in depth. Because of the MPEG-4 standard used for the output video, the analysis process can be done in a wide range of platforms. This trait is beneficial for education and research cooperation purposes

    Multiple Discharges Before Leader Inception in Long Air Gaps Under Positive Switching Impulses

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    There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest probability in the time sequence ‘tip-tip-side-tip-other side’ of the electrode in the first five corona bursts. For each discharge, the first corona current is a single, double exponential pulse, while the following corona currents are mostly a superposition of multiple pulses. The above findings are mainly based on experiments in a 1.4 m air gap under positive switching impulses, in which the voltage, current, and high-speed images were recorded simultaneously. Finally, based on the experimental results, this paper discusses the effects brought by ignoring the multiple discharges on key parameters of leader inception and makes some suggestions to optimise long spark experiments

    Multiple Discharges Before Leader Inception in Long Air Gaps Under Positive Switching Impulses

    Get PDF
    There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest probability in the time sequence ‘tip-tip-side-tip-other side’ of the electrode in the first five corona bursts. For each discharge, the first corona current is a single, double exponential pulse, while the following corona currents are mostly a superposition of multiple pulses. The above findings are mainly based on experiments in a 1.4 m air gap under positive switching impulses, in which the voltage, current, and high-speed images were recorded simultaneously. Finally, based on the experimental results, this paper discusses the effects brought by ignoring the multiple discharges on key parameters of leader inception and makes some suggestions to optimise long spark experiments

    Unit cell geometry of multiaxial preforms for structural composites

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    The objective of this study is to investigate the yarn geometry of multiaxial preforms. The importance of multiaxial preforms for structural composites is well recognized by the industry but, to exploit their full potential, engineering design rules must be established. This study is a step in that direction. In this work the preform geometry for knitted and braided preforms was studied by making a range of well designed samples and studying them by photo microscopy. The structural geometry of the preforms is related to the processing parameters. Based on solid modeling and B-spline methodology a software package is developed. This computer code enables real time structural representations of complex fiber architecture based on the rule of preform manufacturing. The code has the capability of zooming and section plotting. These capabilities provide a powerful means to study the effect of processing variables on the preform geometry. the code also can be extended to an auto mesh generator for downstream structural analysis using finite element method. This report is organized into six sections. In the first section the scope and background of this work is elaborated. In section two the unit cell geometries of braided and multi-axial warp knitted preforms is discussed. The theoretical frame work of yarn path modeling and solid modeling is presented in section three. The thin section microscopy carried out to observe the structural geometry of the preforms is the subject in section four. The structural geometry is related to the processing parameters in section five. Section six documents the implementation of the modeling techniques into the computer code MP-CAD. A user manual for the software is also presented here. The source codes and published papers are listed in the Appendices

    Teleworkbench: an analysis tool for multi-robotic experiments

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    This paper presents a tool, one component of the Teleworkbench system, for analyzing experiments in multi-robotics. The proposed tool combines the video taken by a web cam monitoring the field where the experiment runs and some computer generated visual objects representing important events and information as well as robots’ behavior into one interactive video based on MPEG-4 standard. Visualization and data summarization enables the developer to quickly grasp a situation, whereas the possibility of scrolling through the video and selectively activating information helps him analyzing interesting events in depth. Because of the MPEG-4 standard used for the output video, the analysis process can be done in a wide range of platforms. This trait is beneficial for education and research cooperation purposes.1st IFIP International Conference on Biologically Inspired Cooperative Computing - Robotics and Sensor NetworksRed de Universidades con Carreras en Informática (RedUNCI

    Bimetal based inorganic-carbonic anhydrase hybrid hydrogel membrane for CO2 capture

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    In this study, we synthesized for the first time a bimetal-based inorganic-carbonic anhydrase (CA) hybrid nanoflower to immobilize CA using Cu2+ and Zn2+ instead of single metal ion. Subsequently, the synthesized bimetallic hybrid nanoflowers (CANF) were embedded into the poly(vinyl alcohol) (PVA)-chitosan (CS) hydrogel networks to obtain PVA/CS@CANF hydrogel membrane. The CANF exhibited a significantly higher activity recovery of 70 % compared with 35 % with CA/Zn3(PO4)2 hybrid nanoflowers and 10 % with CA/Cu3(PO4)2 hybrid nanoflowers. The PVA/CS@CANF hydrogel membrane possessed excellent mechanical strength, high catalytic activity, and were easy to flow out without centrifugation or filtration. At the same time, the PVA/CS@CANF displayed higher thermostability, storage stability, and pH stability than free CA and CANF, and superior reusability and CO2 capture capacity. The hydrogel membrane maintained more than 75 % of its original activity after 8 cycles. However, CANF only maintained 12 % of its original activity. Furthermore, the amount of CaCO3 produced by PVA/CS@CANF membrane was 9.0-fold and 2.0-fold compared with free CA and CANF, respectively. Therefore, This approach to synthesizing bimetallic-based protein hybrid hydrogel membrane could have a bright future in CO2 capture

    A Sandwich Electrochemical Immunosensor Using Magnetic DNA Nanoprobes for Carcinoembryonic Antigen

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    A novel magnetic nanoparticle-based electrochemical immunoassay of carcinoembryonic antigen (CEA) was designed as a model using CEA antibody-functionalized magnetic beads [DNA/Fe3O4/ZrO2; Fe3O4 (core)/ZrO2 (shell) nano particles (ZMPs)] as immunosensing probes. To design the immunoassay, the CEA antibody and O-phenylenediamine (OPD) were initially immobilized on a chitosan/nano gold composite membrane on a glassy carbon electrode (GCE/CS-nano Au), which was used for CEA recognition. Then, horseradish peroxidase (HRP)-labeled anti-CEA antibodies (HRP-CEA Ab2) were bound to the surface of the synthesized magnetic ZMP nanoparticles as signal tag. Thus, the sandwich-type immune complex could be formed between secondary antibody (Ab2) modified DNA/ZMPs nanochains tagged by HRP and GCE/CS-nano Au. Unlike conventional nanoparticle-based electrochemical immunoassays, the recognition elements of this immunoassay included both electron mediators and enzyme labels, which obviously simplifies the electrochemical measurement process. The sandwich-type immunoassay format was used for online formation of the immunocomplex of CEA captured in the detection cell with an external magnet. The electrochemical signals derived from HRP during the reduction of H2O2 with OPD as electron mediator were measured. The method displayed a high sensitivity for CEA detection in the range of 0.008–200 ng/mL, with a detection limit of 5 pg/mL (estimated at a signal-to-noise ratio of 3). The precision, reproducibility, and stability of the immunoassay were good. The use of the assay was evaluated with clinical serum samples, and the results were in excellent accordance with those obtained using the standard enzyme-linked immunosorbent assay (ELISA) method. Thus, the magnetic nanoparticle-based assay format is a promising approach for clinical applications, and it could be further developed for the detection of other biomarkers in cancer diagnosis

    The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

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    We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

    An ethylene biosynthesis enzyme controls quantitative variation in maize ear length and kernel yield.

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    Maize ear size and kernel number differ among lines, however, little is known about the molecular basis of ear length and its impact on kernel number. Here, we characterize a quantitative trait locus, qEL7, to identify a maize gene controlling ear length, flower number and fertility. qEL7 encodes 1-aminocyclopropane-1- carboxylate oxidase2 (ACO2), a gene that functions in the final step of ethylene biosynthesis and is expressed in specific domains in developing inflorescences. Confirmation of qEL7 by gene editing of ZmACO2 leads to a reduction in ethylene production in developing ears, and promotes meristem and flower development, resulting in a ~13.4% increase in grain yield per ear in hybrids lines. Our findings suggest that ethylene serves as a key signal in inflorescence development, affecting spikelet number, floral fertility, ear length and kernel number, and also provide a tool to improve grain productivity by optimizing ethylene levels in maize or in other cereals
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