17,584 research outputs found

    Endless tape transport mechanism Patent

    Get PDF
    Endless loop tape transport mechanism for driving and tensioning recording medium in magnetic tape recorde

    Micro-pound extended range thrust stand Patent

    Get PDF
    Micro-pound extended range thrust stand for small rocket engine

    Endless tape cartridge Patent

    Get PDF
    Tape cartridge with high capacity storage of endless-loop magnetic tap

    Learning Membership Functions in a Function-Based Object Recognition System

    Full text link
    Functionality-based recognition systems recognize objects at the category level by reasoning about how well the objects support the expected function. Such systems naturally associate a ``measure of goodness'' or ``membership value'' with a recognized object. This measure of goodness is the result of combining individual measures, or membership values, from potentially many primitive evaluations of different properties of the object's shape. A membership function is used to compute the membership value when evaluating a primitive of a particular physical property of an object. In previous versions of a recognition system known as Gruff, the membership function for each of the primitive evaluations was hand-crafted by the system designer. In this paper, we provide a learning component for the Gruff system, called Omlet, that automatically learns membership functions given a set of example objects labeled with their desired category measure. The learning algorithm is generally applicable to any problem in which low-level membership values are combined through an and-or tree structure to give a final overall membership value.Comment: See http://www.jair.org/ for any accompanying file

    Continuous maintenance and the future ā€“ Foundations and technological challenges

    Get PDF
    High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ā€˜big dataā€™ analytics are the two most important knowledge and skill base required for the continuous maintenance. Advanced computing and visualisation technologies will improve efficiency of the maintenance and reduce through-life cost of the product. Future of continuous maintenance within the Industry 4.0 context also identifies the role of IoT, standards and cyber security

    Towards electron transport measurements in chemically modified graphene: The effect of a solvent

    Full text link
    Chemical functionalization of graphene modifies the local electron density of the carbon atoms and hence electron transport. Measuring these changes allows for a closer understanding of the chemical interaction and the influence of functionalization on the graphene lattice. However, not only chemistry, in this case diazonium chemistry, has an effect on the electron transport. Latter is also influenced by defects and dopants resulting from different processing steps. Here, we show that solvents used in the chemical reaction process change the transport properties. In more detail, the investigated combination of isopropanol and heating treatment reduces the doping concentration and significantly increases the mobility of graphene. Furthermore, the isopropanol treatment alone increases the concentration of dopants and introduces an asymmetry between electron and hole transport which might be difficult to distinguish from the effect of functionalization. The results shown in this work demand a closer look on the influence of solvents used for chemical modification in order to understand their influence

    Oscillator strengths and line widths of dipole-allowed transitions in Ā¹ā“Nā‚‚ between 89.7 and 93.5ā€‚nm

    Get PDF
    Line oscillator strengths in the 20 electric dipole-allowed bands of Ā¹ā“Nā‚‚ in the 89.7ā€“93.5nm (111480ā€“106950cmā»Ā¹) region are reported from photoabsorptionmeasurements at an instrumental resolution of āˆ¼6mƅ (0.7cmā»Ā¹) full width at half maximum. The absorptionspectrum comprises transitions to vibrational levels of the 3pĻƒįµ¤cā€²ā‚„Ā¹Ī£įµ¤āŗ, 3pĻ€įµ¤cĀ³Ī įµ¤, and 3sĻƒgoā‚ƒĀ¹Ī įµ¤Rydberg states and of the bā€²Ā¹Ī£įµ¤āŗ and bĀ¹Ī įµ¤ valence states. The J dependences of band f values derived from the experimental line f values are reported as polynomials in Jā€²(Jā€²+1) and are extrapolated to Jā€²=0 in order to facilitate comparisons with results of coupled Schrƶdinger-equation calculations. Most bands in this study are characterized by a strong J dependence of the band f values and display anomalous P-, Q-, and R-branch intensity patterns. Predissociation line widths, which are reported for 11 bands, also exhibit strong J dependences. The f value and line width patterns can inform current efforts to develop comprehensive spectroscopic models that incorporate rotational effects and predissociation mechanisms, and they are critical for the construction of realistic atmospheric radiative-transfer models.This work was supported in part by NASA Grant No. NNG05GA03G to Wellesley College and Australian Research Council Discovery Program Grant No. DP0558962

    Quick-acting clutch disengages idle drive motor

    Get PDF
    Positive-drive, no drag, over-running clutch is developed to conserve power of idle motor in a low-power system using multiple drive motors. This device is useful where a number of shaft speeds are required with frequent shifting

    The effect of internal gravity waves on cloud evolution in sub-stellar atmospheres

    Get PDF
    Context. Sub-stellar objects exhibit photometric variability which is believed to be caused by a number of processes such as magnetically-driven spots or inhomogeneous cloud coverage. Recent sub-stellar models have shown that turbulent flows and waves, including internal gravity waves, may play an important role in cloud evolution.Aims. The aim of this paper is to investigate the effect of internal gravity waves on dust cloud nucleation and dust growth, and whether observations of the resulting cloud structures could be used to recover atmospheric density information.Methods. For a simplified atmosphere in two dimensions, we numerically solve the governing fluid equations to simulate the effect on dust nucleation and mantle growth as a result of the passage of an internal gravity wave. Furthermore, we derive an expression that relates the properties of the wave-induced cloud structures to observable parameters in order to deduce the atmospheric density.Results. Numerical simulations show that the density, pressure and temperature variations caused by gravity waves lead to an increase of dust nucleation by up to a factor 20, and dust mantle growth rate by up to a factor 1:6, compared to their equilibrium values. Through an exploration of the wider sub-stellar parameter space, we show that in absolute terms, the increase in dust nucleation due to internal gravity waves is stronger in cooler (T dwarfs) and TiO2-rich sub-stellar atmospheres. The relative increase however is greater in warm(L dwarf) and TiO2-poor atmospheres due to conditions less suited for efficient nucleation at equilibrium. These variations lead to banded areas in which dust formation is much more pronounced, and lead to banded cloud structures similar to those observed on Earth. Conclusions. Using the proposed method, potential observations of banded clouds could be used to estimate the atmospheric density of sub-stellar objects
    • ā€¦
    corecore