1,283 research outputs found
Automatic processing system for shadowgraph and interference patterns
The design and operation of an automatic system for the processing of shadowgraph and interference images are described. The system includes a two-coordinate processing table with an optical system for the projection of transparent images onto the photodetector, an image filter in the photodetector field, and a device for controlling the movement of the table and transmitting information to the minicomputer
Coherent lidars based on intracavity heterodyning of echo signals
The development and technical realization of the method of laser sounding of the atmosphere based on the effects of mixing of reference and external fields of scattering inside a laser cavity are presented. An approximate theory of the method was developed on the basis of the investigations using the model of a three-mirror laser. The nonlinear effect of a wideband laser on frequency-dependent external influences of the atmosphere was investigated. The field measurements of gaseous composition of the atmosphere were performed on the basis of a given method of coherent reception using a tunable CO2 laser
Limitary request queue choice mathematical model for the real time streams transfer by means of the mobile ad hoc network radio channel
The mathematical model for the limitary request queue choice for real time streams transfer by means of the wireless self-organized network radio channel is offered. For quality assessment of the multimedia traffic transfer it is offered to use probability of the radio channel request service reservation productivity. The model reflects dependence of channel resources reservation requests service probability on parameters of these inquiries and radio channel parameters. The model is based on the mass service theory mathematical apparatus, probability-and-time graphs and the generating functions use. It is shown that on the basis of the offered mathematical model it is possible to carry out the limitary request queue choice for reservation of a radio channel productivity which allows increasing significantly the probability of high-quality real time streams transfer.Keywords: Mobile ad hoc network, mathematical model, real time flows, requests queue
Electrical control of optical orientation of neutral and negatively charged excitons in n-type semiconductor quantum well
We report a giant electric field induced increase of spin orientation of
excitons in n-type GaAs/AlGaAs quantum well. It correlates strongly with the
formation of negatively charged excitons (trions) in the photoluminescence
spectra. Under resonant excitation of neutral heavy-hole excitons, the
polarization of excitons and trions increases dramatically with electrical
injection of electrons within the narrow exciton-trion bias transition in the
PL spectra, implying a polarization sensitivity of 200 % per Volt. This effect
results from a very efficient trapping of neutral excitons by the quantum well
interfacial fluctuations (so-called "natural" quantum dots) containing resident
electrons.Comment: 18 pages, 4 figure
Hybrid quantum-classical unsupervised data clustering based on the Self-Organizing Feature Map
Unsupervised machine learning is one of the main techniques employed in
artificial intelligence. Quantum computers offer opportunities to speed up such
machine learning techniques. Here, we introduce an algorithm for quantum
assisted unsupervised data clustering using the self-organizing feature map, a
type of artificial neural network. We make a proof-of-concept realization of
one of the central components on the IBM Q Experience and show that it allows
us to reduce the number of calculations in a number of clusters. We compare the
results with the classical algorithm on a toy example of unsupervised text
clustering
Stratifying derived categories of cochains on certain spaces
In recent years, Benson, Iyengar and Krause have developed a theory of
stratification for compactly generated triangulated categories with an action
of a graded commutative Noetherian ring. Stratification implies a
classification of localizing and thick subcategories in terms of subsets of the
prime ideal spectrum of the given ring. In this paper two stratification
results are presented: one for the derived category of a commutative
ring-spectrum with polynomial homotopy and another for the derived category of
cochains on certain spaces. We also give the stratification of cochains on a
space a topological content.Comment: 27 page
Practical experience of using ultrasound flowmeters at the measurement associated petroleum gas
© Published under licence by IOP Publishing Ltd. The results of field tests of several ultrasound flowmeters at existing oil and gas extraction objects are given in the paper. Measured medium - associated petroleum gas. This work aims to create a unified system for measuring the amount and parameters of APG in order to reduce operating costs
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