56,732 research outputs found
Communication and control in an integrated manufacturing system
Typically, components in a manufacturing system are all centrally controlled. Due to possible communication bottlenecking, unreliability, and inflexibility caused by using a centralized controller, a new concept of system integration called an Integrated Multi-Robot System (IMRS) was developed. The IMRS can be viewed as a distributed real time system. Some of the current research issues being examined to extend the framework of the IMRS to meet its performance goals are presented. These issues include the use of communication coprocessors to enhance performance, the distribution of tasks and the methods of providing fault tolerance in the IMRS. An application example of real time collision detection, as it relates to the IMRS concept, is also presented and discussed
Elementary Excitations in One-Dimensional Electromechanical Systems; Transport with Back-Reaction
Using an exactly solvable model, we study low-energy properties of a
one-dimensional spinless electron fluid contained in a quantum-mechanically
moving wire located in a static magnetic field. The phonon and electric current
are coupled via Lorentz force and the eigenmodes are described by two
independent boson fluids. At low energies, the two boson modes are charged
while one of them has excitation gap due to back-reaction of the Lorentz force.
The theory is illustrated by evaluating optical absorption spectra. Our results
are exact and show a non-perturbative regime of electron transport
Microscopic origin of light emission in Al_yGa_{1-y}N/GaN superlattice: Band profile and active site
We present first-principles calculations of AlGaN/GaN superlattice,
clarifying the microscopic origin of the light emission and revealing the
effect of local polarization within the quantum well. Profile of energy band
and distributions of electrons and holes demonstrate the existence of a main
active site in the well responsible for the main band-edge light emission. This
site appears at the position where the local polarization becomes zero. With
charge injection, the calculated optical spectra show that the broadening of
the band gap at the active site leads to the blueshift of emission wavelength
Scattering Rule in Soliton Cellular Automaton associated with Crystal Base of
In terms of the crystal base of a quantum affine algebra ,
we study a soliton cellular automaton (SCA) associated with the exceptional
affine Lie algebra . The solitons therein are labeled
by the crystals of quantum affine algebra . The scatteing rule
is identified with the combinatorial matrix for -crystals.
Remarkably, the phase shifts in our SCA are given by {\em 3-times} of those in
the well-known box-ball system.Comment: 25 page
Box ball system associated with antisymmetric tensor crystals
A new box ball system associated with an antisymmetric tensor crystal of the
quantum affine algebra of type A is considered. This includes the so-called
colored box ball system with capacity 1 as the simplest case. Infinite number
of conserved quantities are constructed and the scattering rule of two olitons
are given explicitly.Comment: 15 page
The Antimicrobial Effect of Silver Ion Impregnation into Endodontic Sealer against Streptococcus mutans.
Pulpal and periradicular diseases are primarily caused by bacterial invasion of the root canal system as a result of caries progression. The presence of residual bacteria at the time of root canal completion (obturation) is associated with significantly higher rate of treatment failure. Re-infection of obturated root canals can be potentially prevented by enhancing the antibacterial activities of root canal obturation materials. We evaluated, in an in vitro model, the antimicrobial efficacy of silver ions added to a common endodontic sealer. For that purpose we performed growth inhibition studies and bacterial viability tests. We measured the zone of inhibition, optical density and performed confocal laser scanning microscopy. Our results show that the silver ions enhance the antimicrobial activity of the root canal sealer against Streptococcus mutans. This study approach may hold promise for studying other biologically based therapies and therefore increasing the success rate of routine orthograde root canal treatment
Simple Algorithm for Factorized Dynamics of g_n-Automaton
We present an elementary algorithm for the dynamics of recently introduced
soliton cellular automata associated with quantum affine algebra U_q(g_n) at
q=0. For g_n = A^{(1)}_n, the rule reproduces the ball-moving algorithm in
Takahashi-Satsuma's box-ball system. For non-exceptional g_n other than
A^{(1)}_n, it is described as a motion of particles and anti-particles which
undergo pair-annihilation and creation through a neutral bound state. The
algorithm is formulated without using representation theory nor crystal basis
theory.Comment: LaTex2e 9 pages, no figure. For proceedings of SIDE IV conferenc
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