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91.
We consider a partial ordered set (POSET) of assembling operations, with known execution durations, that must be accomplished. The assembling operations can be executed on an acyclic network with an identical set of robots on each conveyer (arc). The number of depots (nodes) is a known integer. Between each pair of depots we can locate only one conveyer. We seek an arrangement of the network and a plan that divides the task operations among the conveyers, minimizing the overall task completion time. We use linear programming optimization, subject to reasonably general rules for distributing the operation-fragments among the conveyers. 相似文献
92.
93.
We study isometries of certain non-self-adjoint operator algebras by means of the structure of the complete holomorphic vector fields on their unit balls and the associated partial Jordan triple products. We show that isometries of nest sub-algebras of B(H) are of the form T UTW or T UJT*JW, where U, W are suitable unitary operators and J a fixed involution of H. 相似文献
94.
Baruch Awerbuch Bonnie Berger Lenore Cowen David Peleg 《Random Structures and Algorithms》1994,5(3):441-452
We obtain the first NC algorithm for the low-diameter graph decomposition problem on arbitrary graphs. Our algorithm runs in O(log5(n)) time, and uses O(n2) processors. © 1994 John Wiley & Sons, Inc. 相似文献
95.
We propose and experimentally demonstrate a method for fiber dispersion measurement based on the modulation of laser pulses stretched by the fiber under test. The measured spectrum of the modulated pulses is the result of the interference between the stretched pulse spectra shifted by the modulation harmonics. The interference pattern is processed as in Fourier transform spectral interferometry. Unlike to conventional spectral interferometry, environmental conditions do not affect the interferogram due to the lack of any interferometer; additionally, large dispersions can be characterized by the method proposed. Its high accuracy is demonstrated in experimental comparison with the widely used phase shift technique. 相似文献
96.
We find that discrete noise of inhibiting (signal) molecules can greatly delay the extinction of plasmids in a plasmid replication system: a prototypical biochemical regulatory network. We calculate the probability distribution of the metastable state of the plasmids and show in this example that the reaction rate equations may fail in predicting the average number of regulated molecules even when this number is large, and the time is much shorter than the mean extinction time. 相似文献
97.
?mer Kavaklolu Baruch Schneider 《International Journal of Infrared and Millimeter Waves》2008,29(4):329-352
A rigorous analytical representation for the multiple scattering coefficients of the fields radiated by an infinite grating
of dielectric circular cylinders excited by an obliquely incident plane electromagnetic wave is derived in terms of the “well-known
scattering coefficients of an isolated dielectric cylinder at oblique incidence” and “Schl?milch series”. In addition, a generalized
sum-integral grating equation is acquired for the multiple scattered amplitude of a cylinder at oblique incidence in the grating
in terms of the scattering coefficients of the insulating dielectric circular cylinder at oblique incidence.
相似文献
98.
Vodonos B Weill R Gordon A Bekker A Smulakovsky V Gat O Fischer B 《Physical review letters》2004,93(15):153901
We present a theoretical and experimental study of multiple pulse formation in passively mode-locked lasers. Following a statistical-mechanics approach, the study yields a thermodynamic-like "phase diagram" with boundaries representing cascaded first order phase transitions. They correspond to abrupt creation or annihilation of pulses and a quantized rf power behavior, as system parameters (noise and/or pumping levels) are varied, in excellent accordance with the experiments. Remarkably, individual pulses carry an almost constant quantum of energy. 相似文献
99.
Chiral Pybox (pyridine-2,6-bis(oxazoline)) ligands can be cleanly and efficiently prepared on polystyrene support via a five-step solid-phase synthetic sequence. Cu(I)-complexed polymer-bound Pybox was used as a catalyst in the first heterogeneously catalyzed asymmetric addition of alkynes to imines. Best enantioselectivity was observed with (t)Bu-substituted oxazolines. 相似文献
100.
We propose and numerically demonstrate a simple method for measuring waveforms of optical pulses that have spectral bandwidths much larger than the passband of the measuring system, thus enabling a kind of temporal superresolution. The technique is based on pulse intensity modulation that contains high-order harmonics. Parts of the pulse intensity spectrum that are shifted as a result of the modulation, are moved over (“umklapped”) to the center of the passband, transmitted and then recorded by an oscilloscope. The pulse intensity spectrum is restored by parts from the Fourier transform of a few oscillograms, measured after performing the temporal shifts between the pulse train and the modulation. A similar approach is applied for achieving subwavelength spatial resolution in far -field microscopy. The spatial modulation is performed by a diffraction grating. The method allows one to restore a subwavelength object in a single measurement. 相似文献