17,584 research outputs found
Endless tape transport mechanism Patent
Endless loop tape transport mechanism for driving and tensioning recording medium in magnetic tape recorde
Micro-pound extended range thrust stand Patent
Micro-pound extended range thrust stand for small rocket engine
Endless tape cartridge Patent
Tape cartridge with high capacity storage of endless-loop magnetic tap
Learning Membership Functions in a Function-Based Object Recognition System
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
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 ābig 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
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 93.5ānm
Line oscillator strengths in the 20 electric dipole-allowed bands of Ā¹ā“Nā in the 89.7ā93.5nm (111480ā106950cmā»Ā¹) region are reported from photoabsorptionmeasurements at an instrumental resolution of ā¼6mĆ
(0.7cmā»Ā¹) full width at half maximum. The absorptionspectrum comprises transitions to vibrational levels of the 3pĻįµ¤cā²āĀ¹Ī£įµ¤āŗ, 3pĻįµ¤cĀ³Ī įµ¤, and 3sĻgoāĀ¹Ī įµ¤Rydberg states and of the bā²Ā¹Ī£įµ¤āŗ and bĀ¹Ī įµ¤ valence states. The J dependences of band f values derived from the experimental line f values are reported as polynomials in Jā²(Jā²+1) and are extrapolated to Jā²=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
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
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
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