119,626 research outputs found
Planning and Resource Management in an Intelligent Automated Power Management System
Power system management is a process of guiding a power system towards the objective of continuous supply of electrical power to a set of loads. Spacecraft power system management requires planning and scheduling, since electrical power is a scarce resource in space. The automation of power system management for future spacecraft has been recognized as an important R&D goal. Several automation technologies have emerged including the use of expert systems for automating human problem solving capabilities such as rule based expert system for fault diagnosis and load scheduling. It is questionable whether current generation expert system technology is applicable for power system management in space. The objective of the ADEPTS (ADvanced Electrical Power management Techniques for Space systems) is to study new techniques for power management automation. These techniques involve integrating current expert system technology with that of parallel and distributed computing, as well as a distributed, object-oriented approach to software design. The focus of the current study is the integration of new procedures for automatically planning and scheduling loads with procedures for performing fault diagnosis and control. The objective is the concurrent execution of both sets of tasks on separate transputer processors, thus adding parallelism to the overall management process
Phenomenology of Multi-W Processes in Cosmic Rays
We report on a study of the potential of various cosmic ray physics
experiments to search for Standard Model processes involving the
nonperturbative production of O(30) weak gauge bosons. Whereas present and
near-future experiments are insensitive to proton-induced processes,
neutrino-induced processes give rise to promising signatures and rates in
AMANDA, DUMAND, MACRO and NESTOR provided that a cosmic neutrino flux exists at
levels suggested by recent models of active galactic nuclei. The Fly's Eye
currently constrains the largest region of parameter space characterizing
multi-W phenomena.Comment: (Invited talk presented by A. Ringwald at 17th Johns Hopkins Workshop
on Current Problems in Particle Theory, Particles and the Universe, July
30-August 1, 1993, Budapest, Hungary), 16 pages (LaTeX) + 10 uuencoded
PostScript figures, CERN-TH.7005/93, UCLA/93/TEP/3
Modeling an elastic beam with piezoelectric patches by including magnetic effects
Models for piezoelectric beams using Euler-Bernoulli small displacement
theory predict the dynamics of slender beams at the low frequency accurately
but are insufficient for beams vibrating at high frequencies or beams with low
length-to-width aspect ratios. A more thorough model that includes the effects
of rotational inertia and shear strain, Mindlin-Timoshenko small displacement
theory, is needed to predict the dynamics more accurately for these cases.
Moreover, existing models ignore the magnetic effects since the magnetic
effects are relatively small. However, it was shown recently \cite{O-M1} that
these effects can substantially change the controllability and stabilizability
properties of even a single piezoelectric beam. In this paper, we use a
variational approach to derive models that include magnetic effects for an
elastic beam with two piezoelectric patches actuated by different voltage
sources. Both Euler-Bernoulli and Mindlin-Timoshenko small displacement
theories are considered. Due to the magnetic effects, the equations are quite
different from the standard equations.Comment: 3 figures. 2014 American Control Conference Proceeding
Leeds Met Library Facebook application
At the Leeds Met staff development festival in 2008 a library graduate trainee, Anna Hepworth, took part in a ‘Dragons’ Den’ event which saw staff propose new, innovative ideas to a panel of senior managers. Anna’s suggestion was to develop a Facebook application (or ‘app’) for the library and it was one of the competition winners. Anna’s initial proposal was to create a Leeds Met library catalogue application, but after discussions with members of the library’s ‘technologies for learning’ team it was decided to take the application a stage further, creating a mash-up using data from the library management system (Sirsi-Dynix Symphony). The Facebook application would send a library catalogue search box to a Facebook profile, but would also add value by delivering customised user data, including library record details such as number of issues, reservations and overdues. There would also be links to the library website and online self-service functions from the application
Robustness of controllers designed using Galerkin type approximations
One of the difficulties in designing controllers for infinite-dimensional systems arises from attempting to calculate a state for the system. It is shown that Galerkin type approximations can be used to design controllers which will perform as designed when implemented on the original infinite-dimensional system. No assumptions, other than those typically employed in numerical analysis, are made on the approximating scheme
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