bluuebunny/crossref_metadata_2025 huggingface dataset:
Acceleration of regional housing development in Russia on the basis of industrial housing construction modernization
Authors: Selyutina Larisa , Maleeva Tatyana , Frolova Natalya
Published: May 2019

The article is dedicated to the actual problem of regional housing development. The authors propose to use the existing Russian production facilities of large panel construction, which must be modernized on the basis of modern technologies, as a promising reserve for increasing the volume of housing construction. Currently, EU countries pay considerable attention to cluster strategies as an effective tool for the innovative development of regions and enterprises. Recently, there has been a significant amount of interest to this problem in Russia. It identified distinctive parameters of the formation and implementation of regional cluster construction policies, industrial housing on an innovative basis in comparison with traditional industrial and construction policies. The need for an integrated approach to innovative solutions in the field of technology and construction management has been proved. The need for improving the spatial organization of construction by creating industrial housing construction clusters on the territory of large industrial regions has been justified, which, according to the authors point of view, will help to find a fast solution of the housing problem in St. Petersburg and in Russia as a whole.
Plasma Technology for Producing Coverings on Building Materials
Authors: Lykov Alexey , Mokrova Nataliya
Published: May 2019

Results of plasma processing of construction materials are presented in the article. The article also covers the plasma generator construction and technology of receiving protectively decorative covering on concrete that were developed by the authors. This plasma generator construction and technology provide coverings on concrete with strength and production characteristics that are superior to the existing alternatives. Results of the calculation and experimental research of the surface layer are presented. The technological parameters that influence the characteristics of the covering are given.
Vibration analysis of airfoil on hereditary deformable suspensions
Authors: Usmonov Botir , Rakhimov Quvvatali
Published: May 2019

This paper describes the analyses of the nonlinear vibrations and dynamic stability of an airfoil on hereditary-deformable suspensions. The model is based on two-degree-of-freedom structure in geometrically nonlinear statements. It provides justification for the choice of the weakly singular Abelian type kernel, with rheological parameters. To solve problems of viscoelastic system with weakly singular kernels of relaxation, a numerical method has been used, based on quadrature formulae. With a combination of the Galerkin and the presented method, problems of nonlinear vibrations and dynamic stability in viscoelastic two-degree-of-freedom structure have been solved. A comparison of the results obtained via this method is also presented. In all problems, the convergence of the Galerkin method has been investigated. The implications of material viscoelasticity on vibration and dynamic stability are presented graphically.
Mathematical model of the thermodynamic system during winter concreting of bored piles
Authors: Mestnikov Aleksey , Turantaev Gavril , Fedorov Valeriy
Published: May 2019

The article discusses the development of a mathematical model of the thermodynamic system during winter concreting of bored piles. The processes of heat transfer based on the differential heat equation and the Stefan problem are described. A method for calculating the rationale for the parameters of the energy-saving and gentle thermal treatment of concrete using non-traditional sources of thermal energy is proposed. The solutions for using two-phase thermosyphons as heating elements are considered.
Mathematical descriptions of heat-mass-exchange processes in construction industry at control automation
Authors: Velichkin Vladimir , Zavyalov Vladimir , Solodovnikova Elena , Filippova Elena
Published: May 2019

The paper covers matters arising in building mathematical model of processes at thermal treatment of construction materials. On the basis of analysis of heat energy and moisture flows in intermittent steam chamber and continuous tunnel drying chamber, analytic and structure models of heat-mass-exchange processes in processing vessels are drawn. The structural model of heat-mass-exchange processes allowed to evaluate the relationship of heat energy and moisture flows at heat treatment processes for gypsum and reinforced-concrete articles. The resulting system of interrelated differential equations is based on a structural model. Analytical studies showed that the considering heat treatment units are characterized by non-stationary, non-linear, stochastic and distributed technological parameters. An experimental study of technological devices has shown that in a limited time range, the processes of heat-mass-exchange can be characterized by a system of linear differential equations with constant coefficients with sufficient accuracy for practice. Acceptable allowances and simplifying assumptions at analytical description of heat-mass-exchange processes in processing vessels are considered. As a result of performed research, various mathematical forms (differential equation system, matrix and operator forms) of mathematical models of processing vessels are obtained. The built mathematical models may be applied for constructing the processing vessels with preset dynamic properties, as well for control-system designing by those vessels.
Bim technology in the educational process
Authors: Yakshina Alexandra , Vasilovskaya Galina , Berseneva Maria , Danilovich Elena , Hoffman Oksana
Published: May 2019

In this article we discuss about the main trends by using BIM-technologies in construction in the Russian Federation, possibilities of applying them in construction quality management and in staff training. Weoutlinethenecessity to improve the system of preparation and implementation of BIM-technologies in the new civil engineers educational process within the strategic development of the construction industry because it’s very important for the further development of construction, architecture and other engineering areas. Here we analyze the possibilities of using BIM-technology in education programs for students of various specialties in the absence of real skills to create drawings on the example of the University of Architecture and Civil Engineering.
Loads on cutter teeth for removing asphalt pavement
Authors: Furmanov Denis , Chizhov Vladimir , Tyuremnov Ivan , Troshin Denis
Published: May 2019

Machines and equipment for asphalt pavement milling are widely used throughout the world. With the growth of road construction, the demand for this class of machinery also rises. At the same time, the optimization of design and technological parameters of the milling machines is impossible without a comprehensive study of processes of milling asphalt concrete with the working elements of a cutter. The article provides a brief overview of different approaches to find out the loads on the working bodies of various machines, as well as indicates the advantages and disadvantages of these approaches. We describe the design of a pendulum stand used to study the processes of milling asphalt concrete with a single tooth cutter. We also describe the method of operation of such a stand. The design of the pendulum stand allows us to determine the cutting work, the average, and the instantaneous cutting forces. The work also provides the result of tests of cutting elements during their interaction with samples of asphalt concrete of different grades that are widely used in road construction. We also show the non-linear dependence of cutting resistance forces on the temperature and thickness of penetration of a cutting element. It is noted that working with a slight tooth penetration leads to low energy efficiency of the work process. It is also noted that temperature affects cutting resistance forces significantly less in asphalt concrete containing high amount of gravel.
Flow drilling technology and thread forming - an economical and secure connection in hollow sections and thin-walled components
Authors: Heiler Roland
Published: May 2019

Detachable and highly loadable screw connections can only be realized in thin-walled components and in particular hollow profiles with great effort. The flow drilling technology and subsequent thread forming represents an economical and technically interesting manufacturing alternative. With Flow drilling, a bush is generated by a fast-rotating carbide taper mandrel and a high resistant internal thread can be produced in a subsequent manufacturing process. Conventional weldor rivet nuts can be replaced in many application areas.
Risks and safety in construction by increasing efficiency of investments
Authors: Borkovskaya Victoria , Lyapuntsova Elena , Nogovitsyn Maxim
Published: May 2019

This study focuses on enhancing the effectiveness of investment in construction given the constant threat of new risks. We investigate the types and causes of risks of firms working in the construction industry, draw conclusions about the importance of risks associated with the investment attractiveness of projects, as well as responsibility for the environmental safety. Urbanization and changes in the surrounding area are the dominant trend in the development of modern society. The constant demand of business for commercial real estate, as well as the increase in population growth demands enhanced effectiveness in the construction market, where supply in construction market depends on the economic conditions. The relevance of the research topic is due to the fact that the increasing capital flows in the construction industry pose new challenges for forecasting, statistics and risk control, and a focus on the rates of return mechanisms to hedge against the uncertainty of the future. The aim of the study is a systematic integrated approach to solving problems to improve the efficiency and effectiveness of investments and their protection using a methodological systematic approach, which considers the components of an integrated investment process. We propose a model of risk hedging management, and focus on an analytical methodology of the most relevant risks in modern construction.
High-precision two-phase laser rangefinder PFSD-1,2
Authors: Hayrapetyan Yegisabeth , Petrosyan Hovseph , Hunanyan Hovnan , Tsaturyan Artyom
Published: May 2019

Performing high-precision linear measurements is one of the main tasks of modern engineering geodesy. Consequently, the development and creation of high-precision laser rangefinders and refractometers with a relative measurement error of not more than 3.10-7, becomes an urgent scientific and technical problem.

Wide theoretical and experimental studies in the problem laboratory of geodetic measurements of NUACA have accumulated a sufficient amount of experimental results for the construction of modern high-precision light meter with the determination of the residual part of the phase cycle with an error of 0.03-0.05 mm.

The article discusses issues related to improving the accuracy of linear measurements developed in the NUACA of high-precision light rangefinder. A two-phase modulation measurement method is proposed, when signals shifted by 180° are formed optically using a phase plate at λ/2. This modulation method of linear measurements provided the phase error of linear measurements mφ = 0.03-0.05 mm.

The article also discusses the issue of reducing the modulation power. For this purpose, it is proposed to install a high-quality buffer Q-resonator between the high-quality light modem and the low-quality microwave oscillator.
Dossier : Perspectives franco-brésiliennes autour de l’agroécologie – Aux frontières de l’agroécologie. Les politiques de recherche de deux instituts agronomiques publics français et brésilien
Authors: Ollivier Guillaume , Bellon Stéphane , Deane de Abreu Sá Tatiana , Magda Danièle
Published: May 2019

L’agroécologie en France et au Brésil résulte d’interactions entre la science, des pratiques agricoles et la politique. Nous analysons la manière dont deux institutions publiques de recherche agronomique, l’Empresa Brasileira de Pesquisa Agropecuária (Embrapa) et l’Institut national de la recherche agronomique (Inra), appréhendent ces frontières à l’occasion de sa mise sur leur agenda de programmation. Notre analyse montre comment leurs exercices de programmation étant, plus ou moins, dépendants de leurs contextes politiques nationaux, il en résulte des dynamiques et des cadrages différents de la notion. Précédant l’Inra, l’Embrapa, fortement incité par le gouvernement et les mouvements sociaux, intègre l’agroécologie pour légitimer une recherche alternative, au service des agriculteurs familiaux dans un contexte agricole et politique très clivé et houleux. À l’Inra, l’agroécologie permet la (re)légitimation de l’agronomie pour répondre aux enjeux sociétaux actuels, tout en rejetant la radicalité politique des mouvements sociaux. Elle trouve ensuite un écho dans la politique publique. Nous montrons enfin que la notion donne lieu à des cadrages et débats internes au sein des deux institutions reflétant différentes conceptions du rapport science/société.
Solving optimal control problems using the Picard’s iteration method
Authors: Akkouche Abderrahmane , Aidene Mohamed
Published: May 2019

In this paper, the Picard’s iteration method is proposed to obtain an approximate analytical solution for linear and nonlinear optimal control problems with quadratic objective functional. It consists in deriving the necessary optimality conditions using the minimum principle of Pontryagin, which result in a two-point-boundary-value-problem (TPBVP). By applying the Picard’s iteration method to the resulting TPBVP, the optimal control law and the optimal trajectory are obtained in the form of a truncated series. The efficiency of the proposed technique for handling optimal control problems is illustrated by four numerical examples, and comparison with other methods is made.
Financial support for the competitiveness of employees in the mining industry
Authors: Perevozova Iryna , Babenko Vitalina , Kondur Oksana , Krykhovetska Zoriana , Daliak Nadiia
Published: May 2019

The development of a socially oriented market economy in Ukraine, the effective implementation of reforms in this direction and the improvement of the well-being of the population is not possible without qualitative financial support for the competitiveness of workers, above all, in the mining industry. However, the absence of effective levers of influence on the organization of high-tech production in this area, its considerable intensiveness of material and energy, and its complexity and harm have negatively affected the labor motivation of miners and the profitability of mining enterprises. Therefore, the urgent issues at the current stage of development of Ukraine's mining industry are determining the conditions and opportunities for increasing the competitiveness of employees in this industry. Scientific novelty of the results is to identify, substantiate and analyze the main stages of financial support for the competitiveness of workers in the mining industry under the conditions of a changing vector of the country’s foreign economic policy and of market for products of this industry. The obtained results of the research are the basis to both the study and practical solution of the problem of how to increase the competitiveness of miners in enterprises under various forms of management. This approach involves not only a high level of material incentives for highly qualified specialists in mining, but also a comprehensive development of personnel potential in this industry as a whole.
Assessment of the structural changes of the national economy of Ukraine based on the consistency
Authors: Kovtun Oksana , Opalenko Alla , Ivanylova Oksana
Published: May 2019

This article deals with the assessment of the structural changes of the national economy of Ukraine, which proposed to implement by applying the integrated index of structural changes, assessment of the structural changes of the sectoral structure of GDP, at determining the weighting coefficients and construction which uses the “golden ratio” rule. This approach is based on the theoretical completion of the economics as for the progressive development and transformation of society and the economy of the country according to the technological criterion, as well as the sectoral division of the national economy. The choice of components of the integrated index for structural changes is due to the sectoral division of GDP into industry, agriculture and services, and further distribution according to the sectoral structure of the national economy. The proposed integrated index reflects the consistent (ideal) GDP structure inherent in the post-industrial economy, while the deviation of the values in the real structure shows structural changes in the national economy of Ukraine and 28 countries of the European Union. The research justifies the weighting coefficients for the selected sectors of the economy, depending on the technological complexity of the process of producing goods (works, services). The article deals with the results of the calculation of the integrated index of the structural changes in the sectoral structure of GDP and its structural elements, as well as the analysis of the reasons for the deviations of real indicators from the consistent ones. The calculations show the crisis phenomena in both the Ukrainian economy and the EU countries, which are explained by the debt crisis in the EU in 2013 and the release of the UK with the EU. The domestic economy shows significant deviations in virtually all sectors, indicating a low level of economy, a non-conformity between supply and demand in the labor market, a low level of innovation, and the inertia of transformational processes in the transition to the post-industrial stage of production. The application of the proposed methodology will allow us to identify strategic directions for the development of sectors of the national economy and develop projection scenarios
Information model of the economic efficiency of advertising
Authors: Vinkovska Alina , Kiv Arnold , Koycheva Tatyana , Bodnar Liliia , Donchev Ivan
Published: May 2019

The development of the economy and trade has led to the widespread use of advertising and the need for its constant improvement. There is a vast field of advertising theory. This paper proposes an information model of the functioning of advertising. We introduce ideas about useful and harmful (excess) information. The concept of user’s thesaurus is also introduced. The effectiveness of advertising is determined by the mutual influence of useful and redundant information. Differential equations are formulated on this basis, the solution of which allows to establish the patterns of the influence of psychological characteristics of users and the mode of presentation of information on the effectiveness of advertising.
Stress-testing as a method of macroprudential policy and information security in banking sector
Authors: Berezina Olena , Honcharenko Iryna , Berezhna Lesya , Kunchenko-Kharchenko Valentina
Published: May 2019

The article contains an overview of the essence, history, components, scenarios, methodology and results of stress testing of the Ukrainian banking system. The purpose of this paper is to explore and analyze existing approaches to stress testing as a method of macro-prudential policy of the Central Bank, to determine the results of quantitative risk assessment and financial stability of banks and their readiness to have sufficient capital to cover losses in various macroeconomic scenarios, as well as to develop a model of integrated assessment and rating of banks based on the results of stress testing. In order to summarize the results of the study, a model of integrated assessment was developed and a rating of banks was built based on the analysis of their financial stability, capital adequacy and readiness to withstand the crisis. To solve the problem of qualitative analysis of the stress-testing results in terms of a significant number of indicators and calculations a simulation of the integral indicator is proposed which helps information users group the data, obtain a generalized assessment and form a rating of banks according to the financial stability reserve.
Fractal analysis of the economic sustainability of enterprise
Authors: Matviychuk Andriy , Novoseletskyy Oleksandr , Vashchaiev Serhii , Velykoivanenko Halyna , Zubenko Igor
Published: May 2019

The article deals with the method of calculating the fractal analysis, the time series of economic sustainability of the industrial enterprise on the trend-resistant sustainability were investigated by estimating the depth of the long-term memory of the time series and constructing a phase portrait. According to the approach used, the “depth of the long memory” is estimated in terms of fuzzy sets. The approach to the estimation of the index of economic stability is developed, based on the methods of forming an integrated indicator consisting of an assessment of such subsystems as the industrial and technical, financial-economic and subsystem of main parameters of the market environment. These helps to estimate the economic stability of the enterprise in the conditions of incomplete information from purpose of making effective management decisions. Combination of techniques for the formation of an integral index and a fractal analysis of the assessment of its trend stability showed an effective result, which was confirmed by the experiments.
Manifestation of emergent properties in risk assessment of oil and gas companies
Authors: Khvostina Inesa , Havadzyn Nataliia , Yurchenko Nataliia
Published: May 2019

The article presents a study on risks in oil and gas industry and reveals their causes investigating enterprises activity as a result of emergent properties of systems. The original algorithm of risk assessment process based on emergent properties study is offered. A taxonomy approach and factor analysis are used for purposes of risk evaluation. The risk assessment consists of risks taxonomy, database structure development, identification of risks through impact factors evaluation; economic system emergent properties risks prediction, an integral risk level indicator calculation using taxonomy approach, correlation analysis of integral indicators of risk assessment, preventive measures for minimizing of negative impacts and reducing risks.
Exports of Ukraine as a global challenge for its future
Authors: Sardak Sergii , Radziyevska Svitlana , Us Ivan
Published: May 2019

Exports are critical for the highly open Ukrainian economy which is characterized by the large trade deficit. Since independence the major consumers of the Ukrainian products have been the CIS and the EU. Conflict with Russia led to the significant decline of the volume of Ukraine’s export commodities. The export analysis, based on the data provided by the State Statistics Service of Ukraine for the period of 2010- 2018 allowed to identify the problems and to come up with possible solutions focusing primarily on the role of the Government of Ukraine in strengthening cooperation with the EU. Firstly, it is suggested to take the institutional steps aimed at expanding and deepening the integration towards the common economic space with the EU, especially the common customs space. Secondly, to explore the opportunities of exporting goods to the countries, with which the EU has signed regional trade agreements. The third step is related to the changing role of Ukraine in the global model of the transformation of the world economy and requires the combination of close cooperation with the EU, on the one hand, and the powerful economies, on the other, thereby contributing to the formation of non-confrontational relations between East and West.
Synthesis of β-Selenylated Cyclopentanones via Photoredox-Catalyzed Selenylation/Ring-Expansion Cascades of Alkenyl Cyclobutanols
Authors: Jung Hye Im , Kim Dae Young
Published: May 2019

A photoredox strategy to access β-selenated cyclic ketone derivatives through the coupling reaction of 1-(1-arylvinyl)cyclobutanols with diselenides under blue LED irradiation and an air atmosphere was developed. This reaction employs the easily accessible and shelf-stable diselenides as a selenium radical source, and the reaction has advantages of mild reaction conditions and broad substrate scope.
Enantioselective Protonation of Silyl Enol Ethers Catalyzed by a Chiral Pentacarboxycyclopentadiene-Based Brønsted Acid
Authors: Li Jun , An Shaoyu , Yuan Chao , Li Pingfan
Published: May 2019

The enantioselective protonation of silyl enol ethers was realized in the presence of a pentacarboxycyclopenta-1,3-diene-based chiral Brønsted acid catalyst with water as an achiral proton source to give the corresponding α-aryl ketones in good yields and up to 75% ee.
Use of Strict Patient Selection Criteria to Achieve Significant Surgical Outcomes from a Low DIEP Flap Breast Reconstruction
Authors: Cha Han Gyu , Kang Min Kyu , Han Hyun Ho , Kim Eun Key , Eom Jin Sup
Published: May 2019

Background The low deep inferior epigastric perforator (DIEP) flap was first introduced in 2016 as it had aesthetic advantages over the conventional DIEP flap. With our experience of over 100 low DIEP flap procedures to date, we have conspicuously lowered complication rates and established more definitive criteria to select proper candidates.

Methods We analyzed 103 patients who underwent breast reconstruction with the low DIEP flap at our hospital between May 2014 and June 2018. Demographics, patient selection criteria, flap specifics, surgical outcomes including postoperative complications, and the location of the abdominal scar and umbilicus were reviewed retrospectively.

Results The mean patient age was 46.7 years, and the average body mass index was 23.7 kg/m2. A low DIEP with an average weight of 377 g was utilized within 6 hours 17 minutes in this cohort. There was no significant difference in the rate of venous congestion or fat necrosis compared with the conventional DIEP flap. The average distance from the pubic hairline to the abdominal scar was 0.6 cm and from the anterior superior iliac spine to the abdominal scar was −0.4 cm. The postoperative location of the umbilicus was 7.0 cm above the pubic hairline.

Conclusion The low DIEP flap is not only a reliable option for a breast reconstruction but is an aesthetically superior approach with a lower abdominal scar and natural umbilicus. Patients may benefit from this technique if prudently selected by computed tomography (CT) angiography. A perforator that is larger than 1 mm in diameter and well enhanced on CT angiography from the division of the external iliac artery to the abdominal skin particularly in the intramuscular course should be selected.
Band-to-band transitions and critical points in the near-infrared to vacuum ultraviolet dielectric functions of single crystal urania and thoria
Authors: Mock Alyssa , Dugan Christina , Knight Sean , Korlacki Rafał , Mann J. Matthew , Kimani Martin M. , Petrosky James C. , Dowben Peter A. , Schubert Mathias
Published: May 2019

Band-to-band transition energy parameters for single-crystal actinide samples of uranium oxide and thorium oxide were determined and compared using spectroscopic ellipsometry and critical-point dielectric function analyses. Spectroscopic ellipsometry measurements from the near-infrared to the vacuum ultraviolet spectral region were used to determine the dielectric functions of uranium oxide and thorium oxide. The critical-point structure is similar between UO2 and ThO2 but strongly blue shifted for ThO2. We find bandgap energies of 2.1 eV and 5.4 eV for UO2 and ThO2, respectively.
Transport in InAs/GaSb quantum spin Hall insulators with high-k dielectrics as the top barrier
Authors: Liu Xiaoxue , Li Tingxin , Yao Siqi , Sullivan Gerard , Du Rui-Rui
Published: May 2019

We have studied the low temperature transport properties of devices made of InAs/GaSb quantum wells (QWs), where the molecular beam epitaxy (MBE)-grown top AlGaSb barrier was selectively removed and subsequently replaced by a high-k dielectric hafnium oxide layer. From the perspective of quantum spin Hall insulators, the main transport properties of the InAs/GaSb QWs with a hafnium oxide top barrier are similar to those of the InAs/GaSb QWs with MBE-grown barriers. Specifically, the band inversion could be retained after such barrier substitution, and the degree of band inversion could still be tuned by gates. Furthermore, when the Fermi level is tuned into the bulk gap, the bulk conductance vanishes at low temperatures and the transport of the device is dominated by the edge states.
High rectification in a broadband subwavelength acoustic device using liquid crystals
Authors: Viana Eduardo , Moraes Fernando , Fumeron Sebastien , Pereira Erms
Published: May 2019

Acoustic diodes can be relevant to improve the audible comfort of indoor environments or to provide better ultrasound images. However, such diodes are usually based on nonlinear materials and microstructured and nanostructured asymmetries, making it difficult to produce them. We present in this article a high rectification acoustic device based on the liquid crystal 5CB, forming an escaped radial disclination kept in a conical frustum tube. Solving the wave equation numerically for this system, we observe that the lack of spatial inversion symmetry along the device's axis produces rectifications up to 1300% for a continuous frequency range from 20 Hz to 20 kHz. We performed a study varying the wave frequency, the tube geometry, and the liquid crystal orientation to identify values that produce the maximum acoustic rectification. Because these liquid crystals have been known for a long time and have well-known manipulation techniques, our results have practical significance in designing novel liquid crystal devices, such as acoustic rectification films.
Spin-on-diffussants for doping in transition metal dichalcogenide semiconductors
Authors: Sutar Surajit , Chiappe Daniele , Nuytten Thomas , Conard Thierry , Asselberghs Inge , Lin Dennis , Radu Iuliana
Published: May 2019

Spin-on-diffussant (SoD) processing as a doping technique in two-dimensional semiconductors shows a general process compatibility with materials such as MoS2 and WSe2. The characteristic Raman modes in chemical vapor deposition-grown MoS2 are retained after a phosphorus-based SoD processing at temperatures up to 1000 °C; the evolution of the characteristic Raman peaks with SoD processing indicates a reduction in the intrinsic electron concentration. Electrical measurements show a corresponding p-type shift in the MoS2 MOSFET transfer characteristics and indicate possible oxidation of MoS2 by the SoD processing. Both these effects correlate with XPS measurements which confirm the diffusion of phosphorus atoms into MoS2 and increased atomic percentage of Mo oxide after SoD processing. The p-type shifts in the electrical characteristics correspond to a maximum of 2.4 × 1012 cm–2 change in the intrinsic carrier concentration. Repeating the experiment on WSe2 flake devices leads to similar trends: an increased p-type and a decreased n-type conduction indicating p-type doping and a significant increase in the OFF-state leakage current.
Locally defined quantum emission from epitaxial few-layer tungsten diselenide
Authors: Wu Wei , Dass Chandriker K. , Hendrickson Joshua R. , Montaño Raul D. , Fischer Robert E. , Zhang Xiaotian , Choudhury Tanushree H. , Redwing Joan M. , Wang Yongqiang , Pettes Michael T.
Published: May 2019

Recently, single photons have been observed emanating from point defects in two-dimensional (2D) materials including WSe2, WS2, hexagonal-BN, and GaSe, with their energy residing in the direct electronic bandgap. Here, we report single photon emission from a nominal weakly emitting indirect bandgap 2D material through deterministic strain induced localization. A method is demonstrated to create highly spatially localized and spectrally well-separated defect emission sites in the 750–800 nm regime in a continuous epitaxial film of few-layer WSe2 synthesized by a multistep diffusion-mediated gas source chemical vapor deposition technique. To separate the effects of mechanical strain from the substrate or dielectric-environment induced changes in the electronic structure, we created arrays of large isotropically etched ultrasharp silicon dioxide tips with spatial dimensions on the order of 10 μm. We use bending based on the small radius of these tips—on the order of 4 nm—to impart electronic localization effects through morphology alone, as the WSe2 film experiences a uniform SiO2 dielectric environment in the device geometry chosen for this investigation. When the continuous WSe2 film was transferred onto an array of SiO2 tips, an ∼87% yield of localized emission sites on the tips was observed. The outcomes of this report provide fundamental guidelines for the integration of beyond-lab-scale quantum materials into photonic device architectures for all-optical quantum information applications.
Temperature-dependent carrier transport: Low-complexity model for the infrared optical and radiative properties of nickel
Authors: Orosco J. , Coimbra C. F. M.
Published: May 2019

We propose a framework for modeling the temperature-dependent infrared optical and radiative properties of metals exhibiting nonideal free-carrier dynamics. In order to do so, we derive a parsimonious model that possesses both multivariate (in temperature and wavelength) and single variate (in wavelength) components. The model is realized as the complex-valued relative permittivity and is applicable to optically smooth media. A procedure is outlined for regressing both components of the model under an appropriate set of physical constraints that preclude superfluous degrees of freedom. The procedure is demonstrated by applying the model to nickel, a transition metal of technical significance that possesses nontrivial valency. The resulting model yields practically accurate results for eight data sets spanning four separate studies, representing the approximate wavelength (λ) bandwidth between 1 and 16μm and the approximate temperature (T) range between 0 and 1400 K. The proposed model framework retains phase information and can, therefore, be directly interfaced with more complex Fresnel frameworks, such as those commonly used for modeling systematically or randomly roughened surfaces.
Stable and hard hafnium borides: A first-principles study
Authors: Xie Congwei , Zhang Qi , Zakaryan Hayk A. , Wan Hao , Liu Ning , Kvashnin Alexander G. , Oganov Artem R.
Published: May 2019

We investigate the stability of hafnium borides at zero pressure via the evolutionary crystal structure prediction and first-principles calculations. Our results indicate that the well-known P6/mmm-HfB2 is the only thermodynamically stable phase at zero temperature and pressure, and two more phases (Pnma-HfB and Fm3¯m-HfB12) become thermodynamically stable at higher temperatures. We compute the mechanical properties including bulk, shear and Young’s moduli, Vickers hardness, and fracture toughness for all stable and metastable hafnium borides (∼30 phases) and then study in detail the effect of boron concentration and topology of B-sublattice on their mechanical properties. We show that not only the concentration of boron, but also the topology of the boron sublattice is important for the mechanical properties of hafnium borides. Among the predicted stable and low-energy metastable hafnium borides, the highest possible hardness is exhibited by P6/mmm-HfB2 with graphenelike boron sheets and by phases with 3D boron networks and high B/Hf ratios (e.g., Pnnm-HfB5 and Fm3¯m-HfB12).
Microsecond timescale combustion of aluminum initiated by an underwater electrical wire explosion
Authors: Rososhek A. , Efimov S. , Goldman A. , Tewari S. V. , Krasik Ya. E.
Published: May 2019

We report a direct observation of the microsecond time scale combustion of aluminum realized in underdamped electrical explosions of aluminum wires in the water environment. Experiments were conducted using a pulse power generator delivering a ≤200 kA current amplitude within an ∼1 μs rise-time. Time-resolved spectroscopy was applied to obtain the spectrum of AlO oxide absorption bands, and the temperature of oxides was determined. The results show that decreasing the wire diameter and increasing the discharge current density allow one to decrease the time delay in the appearance of AlO absorption bands to ≤1 μs with respect to the beginning of the wire explosion and significantly increase the rate of aluminum combustion up to ∼1.3 × 103 g/s.
To the theory of gyrotrons with confocal resonators
Authors: Nusinovich Gregory S.
Published: May 2019

In recent years, in addition to the development of traditional gyrotrons with an axially symmetric interaction space, there has been strong interest in developing gyrotrons, whose interaction space is not axially symmetric (e.g., gyrotrons with confocal resonators). The theory of such gyrotrons is presented in this paper. First, equations describing such gyrotrons in the cold-cavity approximation are formulated. Then, the linear theory is developed, which is followed by a simple, single-mode, nonlinear theory. After that, the theory describing the mode interaction in such gyrotrons is presented. Then, an alternative concept of gyrotrons with single and multicavity confocal resonators and sheet electron beams is proposed. This paper also includes the analysis of diffractive losses in confocal resonators and the estimates for curling of the ends of sheet beams of gyrating electrons caused by the space charge forces.
Victorian local government priority for Aboriginal health and wellbeing: a mixed-methods study
Authors: Aron Yudit , Rounsefell Kim , Browne Jennifer , Walker Ruth , Helson Catherine , Atkinson Petah , MacDonald Catherine , Palermo Claire
Published: May 2019

The aim of this study is to identify if Victorian local governments prioritise Aboriginal health and wellbeing issues through policy and explore the key factors influencing policy and program development and implementation. A sequential explanatory mixed-methods study design utilised a survey to quantify commitment to Aboriginal health policy followed by in-depth interviews that explored how and why policy or programs were in place. Data were analysed separately and then interpreted together. Representatives from 39 of Victoria’s 79 local governments (49%) responded to the survey and 14 were interviewed. Seventy-four per cent had policy and programs addressing Aboriginal health and wellbeing. The key factors influencing policy and program development were: (i) the process of policy and program development and implementation and the role of other policies; (ii) the influence of Aboriginal community characteristics; and (iii) advocacy for Aboriginal health and wellbeing. Underpinning these factors was that local government is ‘working together (in partnership and through collaboration) towards reconciliation’. Victorian local governments that participated in this study appear to prioritise Aboriginal health and wellbeing, especially where collaboration with the Aboriginal community is strong. The effect of policies and their subsequent programs on the health of Aboriginal peoples warrants further exploration.
Repetition
Authors: Klinger Susanne
Published: May 2019

Repetition is a common literary device that can be used to create associative networks within a text, parallel structures suggesting similarities in meaning, or a wide span of effects ranging from monotony to excitement. If repetition is a common literary device, then it follows that its translation is a common challenge for the literary translator. However, translators tend to avoid repetition and by doing so often fail to recreate the function the repetition fulfils in the source text. Using Michael Cunningham’s literary travelogue Lands End: A walk in Provincetown and its German translation as a case study, in this paper I will have a closer look at the literary function of repetition and how omitting the repetition in the target text can affect the text’s meaning potential. In addition, I will discuss alternative solutions that maintain the literary function in the target text. In particular, I will argue that the target text does not necessarily need to mirror the linguistic form of the source-text repetition, but can employ other stylistic means to recreate its literary function in the target text.
Facial Expression Recognition Based on Gabor Multi-orientation Feature Fusion
Authors: Liang Xuechen , Yang Lei , Luo Shengda
Published: May 2019

Facial expression is a key to nonverbal communication, which has been confirmed by many different research projects. A change in intensity or magnitude of even one specific facial expression can cause different interpretations. With the continuous and fast development of computer vision and pattern recognition, facial expression recognition has received significant attention recently due to the wide range of commercial and law enforcement application and the availability of feasible technology during 30 years of research. In this thesis, facial expression recognition is studied by applying several commonly used methods in the whole process. By numerical experiment, we find that our approach with Gabor based transformation for face expression feature extraction, combining the advantages of various algorithms, Gabor wavelet transform and non-negative matrix decomposition of facial expressions are used to obtain features, and CNN is used to classify and apply them to facial expression recognition.
Rotation Face Detection Based on Three-Window Convolutional Neural Networks
Authors: Gao Mingyan , Tang Yan
Published: May 2019

In some family photos or special scene pictures, we can find some rotated faces. Most existing methods are based on increasing the features of rotated faces or changing the directions of pictures to augment the training data. However, these methods have their own limitations and can not detect rotated faces accurately. We propose a method based on three-window convolutional neural networks designed by ourselves. We extract the features of faces and change the feature matrices of faces by clockwise rotation and anticlockwise rotation through three-window convolutional layer in order to increase the face features. We retain parameters of the model after training, and convolutional layer replace fully connected layer. According to the heatmap of the sample, our method can predict face region. We carry out the experiments on FDDB and LFW datasets. The experiments on LFW show that our model achieves AUC of 0.9240, and recall of 0.9367 and the experiments on FDDB show that our model achieves recall of 0.9541.
Direct Visual Odometry Using Lines for a Monocular Camera
Authors: Wang Yingge , Wang Zhiqiang , Zhu Qing
Published: May 2019

Most of the visual odometry is based on the matching of the feature points, or the pixel matching of the direct method. However, images have another obvious feature, i.e. the line feature. If we use the point based visual odometry in low texture images, it may result in bad performance in the experiment because of few numbers of feature points. Although in some texture-less environments, it is still possible to reliably estimate the line based on geometric elements. For example, the structured edges are obvious in the indoor scenes. In this paper, we propose a monocular visual odometry method which is based on the combination of direct method and line feature. Then we use TUM-RGB and ICL-NUIM datasets to test our algorithm. Experimental results show that our method improves the robustness and accuracy of the estimation of the position and attitude of the camera.
A Novel Feature Point Matching Method for Skull
Authors: Jiabei Hu , Wen Yang , Shanghao Zhao , Shixiong Wang , Piao Wang , Xiaoning Liu
Published: May 2019

Skull feature points play an important role in computer-aided craniofacial restoration. An improved relative angle histogram algorithm is proposed to match the feature points of the skull, aiming at the low positioning accuracy of the existing skull feature point matching algorithm and the difference of the number of points and the difference of the distribution of the model points. First, the Iterative Closest Point (ICP) algorithm is used to register the original skull model. Then, a new spindle is established for the model after registration. The relative angle of the model points is calculated and the phase diagonal distribution of the model points is calculated. Finally, the model points which are most similar to the histogram distribution of the model feature points are selected as the matching points. Experiments show that the algorithm has achieved good results in the matching of feature points of the skull model.
A Fast Density Peak Clustering Algorithm Optimized by Uncertain Number Neighbors for Breast MR Image
Authors: Hong Fan , Jing Yang , Cun-cun Hou , Ke-zhen Zhang , Ruo-xia Yao
Published: May 2019

Aiming at the characteristics of abundant Magnetic Resonance (MR) image information, uneven gray scale, fuzzy boundary, and a fine structure that is difficult to distinguish and segment, this paper proposes an algorithm for segmenting MR images by an improved density clustering algorithm. First, the superpixel clustering algorithm (SLIC) is used to divide the image into a certain number of ultra-pixel regions and subsequently search the neighborhood of each superpixel according to a pre-specified threshold. Then, the KNN-DPC algorithm, in which the value of K is adaptively determined, is used to obtain the distance information of K nearest neighbors (density) and adjacent superpixels, and image segmentation is completed for each superpixel cluster. Two sets of natural image experiments show that this algorithm has high segmentation accuracy. Experiments on clinical breast MR images showed that this algorithm achieved good results for clinical MR image segmentation.
High-accuracy Three-dimensional Measurement by Improving the Asymmetry of Dithered Patterns
Authors: Ting Wang , Bin Lin , Wanzhen Zhang , Bo Chen
Published: May 2019

The previously proposed dithering defocusing technology performs well for threedimensional (3D) measurement when stripes are relatively wide, yet suffers if stripes are narrow. This paper finds two asymmetries in dithered patterns generated by the Sierra Lite dithering algorithm and verifies the longitudinal fringes are more advantageous for phase-shifting technique over transverse fringes. Furthermore, this paper proposes an algorithm with a meandering scan. In each pattern, the pixels of odd lines are scanned from left to right while the even lines are scanned from right to left. The proposed method avoids the quantization errors propagating in a specific direction and greatly improves the symmetry of longitudinal fringes. Both simulation and experimental results have shown this method can effectively improve accuracy of 3D measurement especially for narrow stripes.