637 research outputs found

    Cross-language Text Classification with Convolutional Neural Networks From Scratch

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    Cross language classification is an important task in multilingual learning, where documents in different languages often share the same set of categories. The main goal is to reduce the labeling cost of training classification model for each individual language. The novel approach by using Convolutional Neural Networks for multilingual language classification is proposed in this article. It learns representation of knowledge gained from languages. Moreover, current method works for new individual language, which was not used in training. The results of empirical study on large dataset of 21 languages demonstrate robustness and competitiveness of the presented approach

    Method of Forming Recommendations Using Temporal Constraints in a Situation of Cyclic Cold Start of the Recommender System

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    The problem of the formation of the recommended list of items in the situation of cyclic cold start of the recommendation system is considered. This problem occurs when building recommendations for occasional users. The interests of such consumers change significantly over time. These users are considered “cold” when accessing the recommendation system. A method for building recommendations in a cyclical cold start situation using temporal constraints is proposed. Temporal constraints are formed on the basis of the selection of repetitive pairs of actions for choosing the same objects at a given level of time granulation. Input data is represented by a set of user choice records. For each entry, a time stamp is indicated. The method includes the phases of the formation of temporal constraints, the addition of source data using these constraints, as well as the formation of recommendations using the collaborative filtering algorithm. The proposed method makes it possible, with the help of temporal constraints, to improve the accuracy of recommendations for “cold” users with periodic changes in their interests

    Recycling Of Carbone Oxides (Co, Co2) Conversion Into Methanol At Atmospheric Pressure Over Mechanochemical Achtivated Cuo-zno-al2o3 Catalyst

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    The catalytic process for methanol production by synthesis gas conversion under the conditions of mechanochemical activation (MCA) of copper-zinc-aluminum oxide catalyst in the temperature range 160–280 °C at a pressure of 0.1 MPa are investigated. The use of mechanical action force is one of the promising ways to improve the activity of heterogeneous catalysts designed to simplify the manufacturing process lines, improving the efficiency of catalytic processes and reduce the cost of the target product. Given the importance of technology for methanol production on copper-zinc-aluminum oxide catalysts and high demand for methanol in the world [1–3], clarification of the peculiarities of the process of methanol production by synthesis gas conversion in terms of mechanical load on the catalyst is important in scientific and applied ways.It is established that specific catalytic activity, performance of methanol synthesis catalyst and the conversion of initial reagents are increased in the conditions of mechanochemical activation, because of the increasing concentration of defects and formation of additional active centers. It is revealed that mechanochemical treatment of copper-zinc-aluminum oxide catalyst can reduce reaction initiation temperature and optimum temperature synthesis by 20–30 °C, and increase the maximum performance of the catalytic system.Increase of the catalyst activity under mechanical stress is explored by increase of defect concentration of crystal lattice of the catalyst, as confirmed by the tests of catalyst surface structure by scanning electron microscopy, Raman spectroscopy and X-ray analysis.A new effective method for synthesis gas conversion into the methanol under conditions of mechanochemical activation of the catalyst can be used in industry as an alternative to methanol production at high pressures

    Modeling of Thermal Modes of the Reflux Condenser of the Absorption Refrigeration Unit

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    Currently, developers of modern refrigeration equipment, in accordance with the plans of the UN, are moving to natural refrigerants (hydrocarbons, carbon dioxide and ammonia) that do not have an adverse technological impact on the ecosystem of the planet. In domestic refrigeration technology, one of the options is absorption refrigeration units, the working body of which is an aqueous ammonia mixture with the hydrogen addition. Having a number of unique advantages over compression analogs, absorption systems are characterized by lower energy characteristics.As the analysis shows, the maximum thermodynamic losses in the absorption aggregates are concentrated in the generating unit when the ammonia is evaporated, it is purified from water vapor and transported to the evaporator. In this connection, the mathematical modeling of the thermal regimes of the reflux condenser is performed, which is responsible for purification and transportation of ammonia vapor.Modeling is carried out on standard designs of absorption refrigeration units taking into account reasonable assumptions and results of own experimental researches. A cellular model is used. Stationary operating modes are modeled due to the high thermal inertia of the processes in the reflux condenser.As a result, the perspective of the thermal insulation installation throughout the reflux section is shown, which makes it possible to increase the energy efficiency by 17 ... 22

    Generalized Method Of Designing Unmanned Remotely Operated Complexes Based On The System Approach

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    Self-propelled underwater systems belong to the effective means of marine robotics. The advantages of their use include the ability to perform underwater work in real time with high quality and without risk to the life of a human operator. At present, the design of such complexes is not formalized and is carried out separately for each of the components – a remotely operated vehicle, a tether-cable and cable winch, a cargo device and a control and energy device. As a result, the time spent on design increases and its quality decreases. The system approach to the design of remotely operated complexes ensures that the features of the interaction of the components of the complex are taken into account when performing its main operating modes. In this paper, the system interaction between the components of the complex is proposed to take into account in the form of decomposition of “underwater tasks (mission) – underwater technology of its implementation – underwater work on the selected technology – task for the executive mechanism of the complex” operations. With this approach, an information base is formed for the formation of a list of mechanisms of the complex, the technical appearance of its components is being formed, which is important for the early design stages. Operative, creative and engineering phases of the design of the complex are proposed. For each phase, a set of works has been formulated that cover all the components of the complex and use the author's existence equations for these components as a tool for system analysis of technical solutions.The perspective of the scientific task of the creative phase to create accurate information models of the functioning of the components of the complex and models to support the adoption of design decisions based on a systematic approach is shown.The obtained results form the theoretical basis for finding effective technical solutions in the early stages of designing remotely operated complexes and for automating the design with the assistance of modern applied computer research and design packages

    Determination of the Heat Distribution in the Raw Cotton Packed in the Coil

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    As a result of experimental studies, a special mathematical model of raw cotton is developed. The effect of density change on the thermal conductivity coefficient is determined. A nonlinear differential equation of heat propagation in coils is obtained. The dependence of the density of raw cotton on the coil height is determined experimentally. The heat flux is intense propagating from denser layers of raw cotton to less dense ones. In a saturated form, the effect of density changes on the propagation of heat is less than in the coils. Pocket spontaneous heating occurs locally with sharp boundaries.An expression is found, which is the general solution of the mathematical model of heat propagation in raw cotton in coils, on the basis of which a number of physical real models can be constructed.The model allows to preliminarily give an estimation of the likely picture of the temperature field in the given microvolumes of raw cotton

    Information Model of Cloud App Scaling with Variable Load Peaks

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    The information model of cloud app was done. It is a formal description of cloud app infrastructure and possible transitions between them, and cloud app current working state classification criterion. Cloud app current state classification criterion on the basis of Page-Hinckley method and calendar of events related to the cloud app working state considers the current state to one of three classes in order to improve the accuracy of prediction of cloud app workload.Proposed criterion was compared with standard offline criterion that analyzes information about the entire time series of cloud app through a considerable time after the events that lead to the load peak, and therefore can\u27t be used when grading in real time. It is shown that the classification of cloud app state is consistent in 92 % of cases.The resulting information model of cloud app scaling with variable load peaks can be used as a component of information technology for cloud app scaling with variable load peaks

    De Bruijn Structured Illumination Studying Within The Task Of Restoring Hands Relief

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    In the course of studies on the problem of restoring hands relief, using the de Bruijn structured illumination, methods of solving this problem are proposed. This is a method of simple quantitative detection of Hough segments on the skin of the hand, a method of qualitative visual evaluation of the effectiveness of the color palette using the dominant color, and a method of the weight coefficients of the components of the color palette.The proposed methods make it possible to quantitatively determine the optimal choice of the color scheme for generating the de Bruijn bands when illumination of the hand, to restore its relief.The work describes the stages of this study, led from visual observation to a full quantitative calculation of the quality of calibration illuminations, with the possibility of their optimal choice.In the course of experiments and observations, the requirements for the technical support of research were developed to achieve the best quality of the images of the hands. Also, the paper presents a high-speed de Bruijn sequence generating algorithm using Lyndon's words, which excludes the search for Euler chains or Hamiltonian cycles, for various kinds of de Bruijn graphs. With its help, the generation of structured light patterns with various color schemes was carried out, with the purpose of further analysis of their use in 3D reconstruction systems of hands

    Analitic Investigation of the Regularities of Changing Dust Concentration During the Abrasive Decrease of Stone Structures

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    In the process of repair or restoration of building structures, it is often necessary to strengthen building structures from limestone-shell rock, concrete, reinforced concrete, hard materials-granite, basalt, etc. by cutting or making cuts of the required size with detachable circles of synthetic diamond and cubic boron nitride (CA and CBN)The cutting process is accompanied by considerable dust formation, which can be both harmful and dangerous factor in the work.The aim of the work is studying the process of dust sedimentation and the regularity of the change in dust concentration during the abrasive cutting of concrete and stone materials.Mathematical models have been developed – dust emission from under the wheel, speed of sedimentation of dust particles depending on their material, size and shape, and also depending on temperature, pressure and humidity, the concentration of dust in the working space and the concentration change during the cutting cycle are calculated.It is shown that the velocity of the sedimentation of particles depends significantly on the shape. The higher the sphericity, the higher the sedimentation rate. The ambient temperature has little effect on the sedimentation rate, in the temperature range (-20 → + 40 °C) at which the operation takes place.The sedimentation rate of dust particles generated by cutting the most common building stone materials also differs slightly. Almost the same sedimentation rate has dust particles obtained by cutting basalt and concrete. A bit higher is the sedimentation rate of particles from granite.The sedimentation rate of particles of generated dust is about 600-700 cm/h or 10-11 cm/min for particles measuring 6 μm. This means that at a production height of about 2 m (200 cm) during the operating cycle (about 3 min), the dust will remain at an altitude of about 1.5 m, i.е. practically remains in the working area. This gives grounds to assert about a high concentration of dust during the cutting cycle (about 4.8 108/m3)

    Hypothesis of Rfmra Development – the Receptor-focused Magnetic and Resonant Anesthesia

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    This article is described the hypothesis of the solution how to create the "ideal anesthesia". Theoretical justification of the innovative technique of the Receptor-focused Magnetic Resonance anesthesia is offered. It should be use the "ideal anesthetic" as which the electromagnetic model of a medicinal preparation for anesthesia acts. Stages of carrying out the offered type of anesthesia have offered. For the practical application of the proposed idea it would be implemented a number of innovations. First, it includes technologies of a magnetic and resonant tomography of high resolution (less than 100 microns). At the second, it would be technologies of creation electromagnetic models of the existing medical preparations. Than it would be on-line technologies of formation the 3D base of addresses of receptors for anesthesia of organism of a particular person. In addition, technologies of a triggering the cascade of biochemical reactions is proposed, by the modeling of pharmacodynamics electromagnetic models of a medicinal preparation.Such type of anesthesia will allow to avoid side effects of medical preparations at stages of an absorption, distribution, removal that are caused by the mass of drug and, in addition, respectively, to reach therapeutic effect only by means of electromagnetic model of a medicinal preparation for anesthesia
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