1,176 research outputs found

    Automatic processing system for shadowgraph and interference patterns

    Get PDF
    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

    Long-term production planning problem: scheduling, makespan estimation and bottleneck analysis

    Get PDF
    In this paper, a long-term production planning problem is considered with the objective criteria Cmax and Tmax and under resource capacity and precedence constraints. The case study presented is characterized by four years planning horizon, 3552 operations, 51 workers and 57 units of equipment. The solution method elaborated in this study is a heuristic algorithm. Its performances are evaluated in numerical experiments. New procedures for makespan and resource load estimation are developed in order to identify bottleneck resources. The makespan estimation algorithm is tested on the well-known PSPLIB benchmark library where the best known lower bounds are improved for 5 instances. This procedure can also be used for the estimation of the gap from optimal value of the makespan time provided by the heuristic algorithm

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

    Get PDF
    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

    Quantum Oscillations of Elastic Moduli and Softening of Phonon Modes in Metals

    Full text link
    In this paper we present a theoretical analysis of the effect of magnetostriction on quantum oscillations of elastic constants in metals under strong magnetic fields. It is shown that at low temperatures a significant softening of some acoustic modes could occur near peaks of quantum oscillations of the electron density of states (DOS) at the Fermi surface (FS). This effect is caused by a magnetic instability of a special kind, and it can give rise to a lattice instability. We also show that the most favorable conditions for this instability to be revealed occur in metals whose Fermi surfaces include nearly cylindrical segments.Comment: 5 pages, 1 figur

    Transformación digital de la economía rusa: desafiando el rango más alto en el desarrollo de la innovación global

    Get PDF
    A simple prognostic method was applied to estimate the percentage ratio of the digital economy in Russia’s GDP relying on technology solutions expenditure and sectoral investment. The research indicates a significant impact of Russia’s digital sector on innovation development in B2B, B2G, and B2C segments. The prognostic analysis shows the extension of on-line education, social networking, e-commerce, private and corporate banking, and end-to-end technology solutions in manufacturing. The findings point at the opportunity for the sectoral investment extension and steady annual growth 7-8 % in the next few years. Due to requirements on updating the technological solutions in the related public services, the digital sphere can support the annual growth in the national economy by 1,0-1,2 % until 2024. Respectively the digital economy in Russia will be growing faster the world's average to provide the sector’s contribution of 8,0-8,1 % in GDP by 2024. The findings show the digital platforms are becoming a driver for innovation development integrating the production process, cloud resources, data analysis, and e-learning services. The research contains hints on improving the research efficiency and winning the talent battle that promises to improve the country’s global innovation and economic ranks.Un método de pronóstico simple aplicado para estimar la relación porcentual de la economía digital en el PIB de Rusia que se basa en el gasto en soluciones tecnológicas y la inversión sectorial. La investigación indica un impacto significativo del sector digital de Rusia en el desarrollo de la innovación en los segmentos B2B, B2G y B2C. El análisis de pronóstico muestra la extensión de la educación en línea, las redes sociales, el comercio electrónico, la banca privada y corporativa y las soluciones tecnológicas integrales en la fabricación. Los hallazgos apuntan a una oportunidad para la extensión de la inversión sectorial y un crecimiento anual constante del 7-8% en los próximos años. Debido a los requisitos de actualización de las soluciones tecnológicas en los servicios públicos relacionados, la esfera digital puede soportar el crecimiento anual de la economía nacional en un 1,0-1,2% hasta 2024. Respectivamente, la economía digital en Rusia crecerá más rápido que la media mundial para proporcionar la contribución del sector 8,0-8,1% en el PIB para 2024. Los hallazgos muestran que las plataformas digitales se están convirtiendo en un motor para el desarrollo de la innovación integrando el proceso de producción, los recursos en la nube, el análisis de datos y los servicios de aprendizaje electrónico. La investigación contiene sugerencias para mejorar la eficiencia de la investigación y ganar la batalla del talento que promete mejorar la innovación global y la clasificación económica del país

    Transfer of 0-order coherence matrix along spin-1/2 chain

    Full text link
    In this work, we study transfer of coherence matrices along spin-1/2 chains of various length. Unlike higher order coherence matrices, 0-order coherence matrix can be perfectly transferred if its elements are properly fixed. In certain cases, to provide the perfect transfer, an extended receiver together with optimized its unitary transformation has to be included into the protocol. In this work, the asymptotic perfectly transferable 0-order coherence matrix for an infinitely long chain is considered and deviation of a perfectly transferred state from this asymptotic state is studied as a function of the chain length for various sizes of the extended receiver. The problem of arbitrary parameter transfer via the nondiagonal elements of the 0-order coherence matrix is also considered and optimized using the unitary transformation of the extended receiver.Comment: 32 pages, 5 figure

    Electrical control of optical orientation of neutral and negatively charged excitons in n-type semiconductor quantum well

    Full text link
    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
    corecore