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

Simulation of the software-defined network for a high-performance computing cluster

The study considers the issues of using the software-defined networks, the current state of the research trends in this area and the most significant projects. The simulation of a high-performance computer network for increase in the performance of the university computing cluster due to the optimization of topology and network traffic between the computational nodes is describe

Justification for the decision on loading channels of the network of geoecological monitoring of resources of the agroindustrial complex

The article is devoted to solving an urgent scientific and technical problem. It consists of developing an algorithm .This is used for estimating the recommended buffer size of requests of transmitting data streams. So,this has been done in a flying self-organizing network .Therefore, it is used to ensure geoecological monitoring of the resources of the agro-industrial complex. However, Studies have shown that to ensure the required quality of data streams transmission. Thus, it is advisable to carry out preliminary reservation of channel performance. Hence, it is possible to increase the likelihood of servicing requests of the transmission of data streams, as well as to increase the load of network channels by buffering incoming requests of the transmission of data streams. So, the developed algorithm makes it possible to substantiate the decision-making to increase the channel load and ensure an acceptable delay in the start of data streams transmission .Therefore ,it has been done in a flying self-organizing network. Hence, the studies carried out the correctness of the algorithm and the expediency of its application. However, in practice the process of tuning the channels of a flying self-organizing network has been carried

Some Methodological Aspects of Selection Serials to Be Included in the Information Environment for Researchers in a Technical or Natural Science (by Example of Optoelectronics and Optical Systems)

A comprehensive citation analysis-based methodology for selecting the world scientific serials to be included in information environment for researchers in a specific natural or technical science is featured. The case study was fulfilled for serials to be included in information environment for researchers in optoelectronics and optical systems (OOS) with the use of Journal Citation Reports (JCR) data. The indices taken for serials evaluation were: total citedness of a serial in the selected journals specialized in OOS; the “discipline impact factor” (Hirst 1978) i.e. the impact factor which numerator is the magnitude of a serial citedness not by all the JCR-indexed journals, but by the ones specialized in OOS, the denominator being the number of papers in a cited serial; the magnitude of total citedness of the journals specialized in OOS in a serial under evaluation; the “discipline susceptibility factor” of a serial (Lazarev and Skalaban 2016; Lazarev et al. 2017), i.e. the number of citations to the mentioned specialized journals made in a serial being evaluated divided by the number of papers in a citing serial. The citation window is one year, the publication window is “5+1” years (i.e. 5 previous years plus the year of citing). With the application of the outlined methodology, the selection of serials believed to be necessary to implement research in OOS has been accomplished, and after application of threshold values, merging and elimination some of the data, the list of 538 serials has been determined. The second pair of indices reflects the susceptibility of the serials being evaluated to the research field represented by cited specialized journals

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

Diffraction based Hanbury Brown and Twiss interferometry performed at a hard x-ray free-electron laser

We demonstrate experimentally Hanbury Brown and Twiss (HBT) interferometry at a hard X-ray Free Electron Laser (XFEL) on a sample diffraction patterns. This is different from the traditional approach when HBT interferometry requires direct beam measurements in absence of the sample. HBT analysis was carried out on the Bragg peaks from the colloidal crystals measured at Linac Coherent Light Source (LCLS). We observed high degree (80%) spatial coherence of the full beam and the pulse duration of the monochromatized beam on the order of 11 fs that is significantly shorter than expected from the electron bunch measurements.Comment: 32 pages, 10 figures, 2 table