A CDCL-style calculus for solving non-linear constraints

In this paper we propose a novel approach for checking satisfiability of non-linear constraints over the reals, called ksmt. The procedure is based on conflict resolution in CDCL style calculus, using a composition of symbolical and numerical methods. To deal with the non-linear components in case of conflicts we use numerically constructed restricted linearisations. This approach covers a large number of computable non-linear real functions such as polynomials, rational or trigonometrical functions and beyond. A prototypical implementation has been evaluated on several non-linear SMT-LIB examples and the results have been compared with state-of-the-art SMT solvers.Comment: 17 pages, 3 figures; accepted at FroCoS 2019; software available at <http://informatik.uni-trier.de/~brausse/ksmt/

Laplace transformations of hydrodynamic type systems in Riemann invariants: periodic sequences

The conserved densities of hydrodynamic type system in Riemann invariants satisfy a system of linear second order partial differential equations. For linear systems of this type Darboux introduced Laplace transformations, generalising the classical transformations in the scalar case. It is demonstrated that Laplace transformations can be pulled back to the transformations of the corresponding hydrodynamic type systems. We discuss periodic Laplace sequences of with the emphasize on the simplest nontrivial case of period 2. For 3-component systems in Riemann invariants a complete discription of closed quadruples is proposed. They turn to be related to a special quadratic reduction of the (2+1)-dimensional 3-wave system which can be reduced to a triple of pairwize commuting Monge-Ampere equations. In terms of the Lame and rotation coefficients Laplace transformations have a natural interpretation as the symmetries of the Dirac operator, associated with the (2+1)-dimensional n-wave system. The 2-component Laplace transformations can be interpreted also as the symmetries of the (2+1)-dimensional integrable equations of Davey-Stewartson type. Laplace transformations of hydrodynamic type systems originate from a canonical geometric correspondence between systems of conservation laws and line congruences in projective space.Comment: 22 pages, Late

Cutting Edge Geometry Effect on Plastic Deformation of Titanium Alloy

The paper presents experimental studies of ОТ4 titanium alloy machining with cutting edges of various geometry parameters. Experiments were performed at a low speed by the scheme of free cutting. Intensity of plastic shear strain was set for defining of cutting edge geometry effect on machining. Images of chip formed are shown. Estimation of strain magnitude was accomplished with digital image correlation method. Effect of rake angle and cutting edge angle has been studied. Depth of deformed layer and the area of the plastic strain is determine. Results showed that increasing the angle of the cutting edge inclination results in a change the mechanism of chip formation

Planar and 3D fibrous polyaniline-based materials for memristive elements

We discuss the effect of structure formation of Langmuir polyaniline layers on the performance of memristive thin-film elements as well as the morphology and conductivity of electrospinned PANI–PEO nonwovens

Parameter Identification of the Agent-Based Model for Managing a Regional Industrial Complex

Current challenges facing the Russian economy require models to optimise industrial management processes at the regional level. Therefore, a three-level hierarchical agent-based model for minimax control of the regional industrial complex is considered in this research. The study aims to develop an approach to solving a parameter identification problem of the agent-based model for managing the industrial complex of Sverdlovsk oblast. To this end, the paper presents a theoretical justification for the implemented approach, a formalisation of the aforementioned problem, and an algorithm for constructing and selecting models to assess management system parameters. The method of linear regression analysis was applied to solve the identification problem. The proposed approach was tested using data on 28 types of industrial activity in Sverdlovsk oblast for 2005–2021. The phase vector of statistical identification models was defined by the following parameters: the average annual number of employees of enterprises; fixed assets; gross value added; volume of shipped goods, performed works and services; balanced financial results of enterprises; investment in fixed capital; costs of implementing and using digital technologies. The control vector was determined by the factors of attracting budgetary and other (external) funds. As a result, 125 high-quality models were built to solve parameter identification problems of the agent-based model used for managing the industrial complex of Sverdlovsk oblast. The obtained statistical models can be used to establish communication between agents, clarify their specificity, calculate and assess management performance. The proposed approach can be applied to predict the development of regional industrial complexes in accordance with planned control actions, as well as to calculate control actions necessary to achieve target parameters.Новые вызовы, стоящие перед отечественной экономикой, требуют построения моделей, позволяющих адекватно оптимизировать процессы управления промышленностью на уровне региона. Данная работа посвящена разработке агент-ориентированной модели трехуровневого иерархического минимаксного управления региональным промышленным комплексом. Целью настоящего исследования является разработка методики решения задачи идентификации параметров агент-ориентированной модели управления промышленным комплексом региона на примере Свердловской области. Для выполнения поставленной цели предложено теоретическое обоснование реализуемого подхода, приведена формализация задачи идентификации параметров системы управления промышленным комплексом региона, описан алгоритм построения и отбора моделей для оценки параметров системы управления. В качестве метода решения задачи идентификации выбран подход на базе линейного регрессионного анализа. Подготовка информационной базы для апробации подхода проводилась в условиях Свердловской области по 28 видам экономической деятельности, относящихся к промышленному производству, по данным за 2005–2021 гг. При построении статистических моделей идентификации фазовый вектор задается следующими параметрами: среднегодовая численность работников предприятий, основные фонды, валовая добавленная стоимость, объем отгруженных товаров, выполненных работ и услуг, сальдированный финансовый результат организаций, инвестиции в основной капитал, затраты на внедрение и использование цифровых технологий. Вектор управления задан факторами привлечения бюджетных средств, а также привлечения средств кроме бюджетных (из внешних источников). В результате исследования построено 125 моделей достаточно высокого качества, которые могут быть использованы в решении задачи идентификации параметров для построения агент-ориентированной модели управления процессами развития промышленности Свердловской области. Полученные статистические модели позволяют установить связь между агентами, уточнить их специфику, рассчитать и дать оценку результатов применения механизмов управления. Предложенный подход применим для построения прогнозов развития регионального промышленного комплекса в соответствии с планируемыми управляющими воздействиями, а также для вычисления оптимального набора управляющих воздействий для достижения промышленностью целевых параметров

Carbon Supported Polyaniline as Anode Catalyst: Pathway to Platinum-Free Fuel Cells

The effectiveness of carbon supported polyaniline as anode catalyst in a fuel cell (FC) with direct formic acid electrooxidation is experimentally demonstrated. A prototype FC with such a platinum-free composite anode exhibited a maximum room-temperature specific power of about 5 mW/cm2Comment: 11 pages, 3 Postscript figures, atricle tex styl

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Resonant X-ray Scattering in Manganites - Study of Orbital Degree of Freedom -

Orbital degree of freedom of electrons and its interplay with spin, charge and lattice degrees of freedom are one of the central issues in colossal magnetoresistive manganites. The orbital degree of freedom has until recently remained hidden, since it does not couple directly to most of experimental probes. Development of synchrotron light sources has changed the situation; by the resonant x-ray scattering (RXS) technique the orbital ordering has successfully been observed . In this article, we review progress in the recent studies of RXS in manganites. We start with a detailed review of the RXS experiments applied to the orbital ordered manganites and other correlated electron systems. We derive the scattering cross section of RXS where the tensor character of the atomic scattering factor (ASF) with respect to the x-ray polarization is stressed. Microscopic mechanisms of the anisotropic tensor character of ASF is introduced and numerical results of ASF and the scattering intensity are presented. The azimuthal angle scan is a unique experimental method to identify RXS from the orbital degree of freedom. A theory of the azimuthal angle and polarization dependence of the RXS intensity is presented. The theoretical results show good agreement with the experiments in manganites. Apart from the microscopic description of ASF, a theoretical framework of RXS to relate directly to the 3d orbital is presented. The scattering cross section is represented by the correlation function of the pseudo-spin operator for the orbital degree of freedom. A theory is extended to the resonant inelastic x-ray scattering and methods to observe excitations of the orbital degree of freedom are proposed.Comment: 47 pages, 24 figures, submitted to Rep. Prog. Phy

A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors

The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices

Overview of JET results for optimising ITER operation

The JET 2019–2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power in 2019–2020, and tested the technical and procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle (α) physics in the coming D–T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed shattered pellet injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design and operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D–T benefited from the highest D–D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER