21,398 research outputs found
Flueric-controller pneumatic stepping motor system
Nutating stepping motor consists of an output rotating gear and a nutating gear. A flueric logic circuit controls the nutating motor. The complete system constitutes a reliable, open loop actuator system with inherently high output stiffness, reasonable slewing speeds and small step size
Spatial interference from well-separated condensates
We use magnetic levitation and a variable-separation dual optical plug to
obtain clear spatial interference between two condensates axially separated by
up to 0.25 mm -- the largest separation observed with this kind of
interferometer. Clear planar fringes are observed using standard (i.e.
non-tomographic) resonant absorption imaging. The effect of a weak inverted
parabola potential on fringe separation is observed and agrees well with
theory.Comment: 4 pages, 5 figures - modified to take into account referees'
improvement
An algorithm for determining program feasibility of a multi-mode PAM commutator telemetry system Technical report no. 10
Algorithm formulation for evaluation of strapping arrangement programs for PAM multimode commutation system of Saturn telemetry syste
Dynamic spin response of a strongly interacting Fermi gas
We present an experimental investigation of the dynamic spin response of a
strongly interacting Fermi gas using Bragg spectroscopy. By varying the
detuning of the Bragg lasers, we show that it is possible to measure the
response in the spin and density channels separately. At low Bragg energies,
the spin response is suppressed due to pairing, whereas the density response is
enhanced. These experiments provide the first independent measurements of the
spin-parallel and spin-antiparallel dynamic and static structure factors and
open the way to a complete study of the structure factors at any momentum. At
high momentum the spin-antiparallel dynamic structure factor displays a
universal high frequency tail, proportional to , where is the probe energy.Comment: Replaced with final versio
Multiobjective analysis for the design and control of an electromagnetic valve actuator
The electromagnetic valve actuator can deliver much improved fuel efficiency and reduced emissions in spark ignition (SI) engines owing to the potential for variable valve timing when compared with cam-operated, or conventional, variable valve strategies. The possibility exists to reduce pumping losses by throttle-free operation, along with closed-valve engine braking. However, further development is required to make the technology suitable for accept- ance into the mass production market. This paper investigates the application of multiobjective optimization techniques to the conflicting objective functions inherent in the operation of such a device. The techniques are utilized to derive the optimal forceādisplacement characteristic for the solenoid actuator, along with its controllability and dynamic/steady state performance
Statistical quality control applied to a telemetry system acceptance prodedure Technical report no. 13
Statistical quality control applied to telemetry system acceptance procedur
Human subjective response to steering wheel vibration caused by diesel engine idle
This study investigated the human subjective response to steering wheel vibration of the type caused by a four-cylinder diesel engine idle in passenger cars. Vibrotactile perception was assessed using sinusoidal amplitude-modulated vibratory stimuli of constant energy level (r.m.s. acceleration, 0.41 m/s(2)) having a carrier frequency of 26 Hz (i.e. engine firing frequency) and modulation frequency of 6.5 Hz (half-order engine harmonic). Evaluations of seven levels of modulation depth parameter m (0.0, 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0) were performed in order to define the growth function of human perceived disturbance as a function of amplitude modulation depth. Two semantic descriptors were used (unpleasantness and roughness) and two test methods (the Thurstone paired-comparison method and the Borg CR-10 direct evaluation scale) for a total of four tests. Each test was performed using an independent group of 25 individuals. The results suggest that there is a critical value of modulation depth m = 0.2 below which human subjects do not perceive differences in amplitude modulation and above which the stimulus-response relationship increases monotonically with a power function. The Stevens power exponents suggest that the perceived unpleasantness is non-linearly dependent on modulation depth m with an exponent greater than 1 and that the perceived roughness is dependent with an exponent close to unity
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