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Acta Mathematica Scientia 2010年第2期30卷 595-620页

作者： oleg schilling Marco Latini Lawrence Livermore National Laboratory Applied and Computational Mathematics California Institute of Technology CNA Corporation

The dynamics of the reshocked multi-mode Richtmyer-Meshkov instability is investigated using 513 × 257^2 three-dimensional ninth-order weighted essentially nonoscil- latory shock-capturing simulations. A two-mode initial perturbation with superposed ran- dom noise is used to model the Mach 1.5 air/SF6 Vetter-Sturtevant shock tube experiment. The mass fraction and enstrophy isosurfaces, and density cross-sections are utilized to show the detailed flow structure before, during, and after reshock. It is shown that the mixing layer growth agrees well with the experimentally measured growth rate before and after reshock. The post-reshock growth rate is also in good agreement with the prediction of the Mikaelian model. A parametric study of the sensitivity of the layer growth to the choice of amplitudes of the short and long wavelength initial interfacial perturbation is also pre- sented. Finally, the amplification effects of reshock are quantified using the evolution of the turbulent kinetic energy and turbulent enstrophy spectra, as well as the evolution of the baroclinic enstrophy production, buoyancy production, and shear production terms in the enstrophy and turbulent kinetic transport equations.

关键词： Richtmyer-Meshkov instability reshock mixing properties weighted essen-tially nonoscillatory (WENO) method

DATA PREORDERING IN GENERALIZED PAV ALGORITHM FOR MONOTONIC REGRESSION

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Journal of Computational Mathematics 2006年第6期24卷 771-790页

作者： oleg Burdakov Anders Grimvall oleg Sysoev Department of Mathematics LinkSping University SE-58183 Link6ping Sweden

Monotonic regression （MR） is a least distance problem with monotonicity constraints induced by a partiaily ordered data set of observations. In our recent publication [In Ser. Nonconvex Optimization and Its Applications, Springer-Verlag, （2006） 83, pp. 25-33], the Pool-Adjazent-Violators algorithm （PAV） was generalized from completely to partially ordered data sets （posets）. The new algorithm, called CPAV, is characterized by the very low computational complexity, which is of second order in the number of observations. It treats the observations in a consecutive order, and it can follow any arbitrarily chosen topological order of the poset of observations. The CPAV algorithm produces a sufficiently accurate solution to the MR problem, but the accuracy depends on the chosen topological order. Here we prove that there exists a topological order for which the resulted CPAV solution is optimal. Furthermore, we present results of extensive numerical experiments, from which we draw conclusions about the most and the least preferable topological orders.

关键词： Quadratic programming Large scale optimization Least distance problem,Monotonic regression Partially ordered data set Pool-adjacent-violators algorithm.

Searching For Wide Binary Stars with Non-coeval Components in the Southern Sky

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Research in Astronomy and Astrophysics 2023年第5期23卷 230-235页

作者： Alexey Kniazev oleg Malkov South African Astronomical Observatory Cape Town7935South Africa Southern African Large Telescope Cape Town7935South Africa Special Astrophysical Observatory Nizhnij ArkhyzKarachai-Circassia369167Russia Sternberg State Astronomical Institute MoscowUniversitetsky ave.13Russia Institute of Astronomy Russian Academy of Sciences48 Pyatnitskaya St.Moscow 119017Russia

We have completed our observational program to search for wide binary systems with non-coeval components in the southern sky and report our results *** final set of four systems was spectroscopically investigated in this *** binary systems with components of different ages were found among *** into account our previous studies,we estimate the fraction of such binaries(i.e.,binaries formed,presumably,by capture)to be not higher than 0.06%.The study will be continued on the northern sky.

关键词： (stars:)binaries general-(stars:)binaries visual-stars formation

The concept of sUAS/DL-based system for detecting and classifying abandoned small firearms

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Defence Technology（防务技术） 2023年第12期30卷 23-31页

作者： Jungmok Ma oleg A.Yakimenko Department of Defense Science Korea National Defense University(KNDU)Republic of Korea Department of Systems Engineering Naval Postgraduate School(NPS)USA

Military object detection and identification is a key capability in surveillance and *** is a major factor in warfare effectiveness and warfighter ***,portable,and rapidly deployable small unmanned aerial systems(s UAS)in conjunction with powerful deep learning(DL)based object detection models are expected to play an important role for this *** prove overall feasibility of this approach,this paper discusses some aspects of designing and testing of an automated detection system to locate and identify small firearms left at the training range or at the *** a system is envisioned to involve an s UAS equipped with a modern electro-optical(EO)sensor and relying on a trained convolutional neural network(CNN).Previous study by the authors devoted to finding projectiles on the ground revealed certain challenges such as small object size,changes in aspect ratio and image scale,motion blur,occlusion,and *** study attempts to deal with these challenges in a realistic operational scenario and go further by not only detecting different types of firearms but also classifying them into different *** study used a YOLOv2CNN(Res Net-50 backbone network)to train the model with ground truth data and demonstrated a high mean average precision(m AP)of 0.97 to detect and identify not only small pistols but also partially occluded rifles.

关键词： Small firearms Object detection Deep learning Small unmanned aerial systems

A New Generation of Rules-based Approach:Mivar-based Intelligent Planning of Robot Actions(MIPRA)and Brains for Autonomous Robots

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Machine Intelligence Research 2024年第5期21卷 919-940页

作者： oleg Varlamov Dmitry Aladin Department of Information Processing and Management Systems RI MIVARBauman Moscow State Tchnical University(BMSTU)Moscow105005Russian Federation

To create autonomous robots,both hardware and software are *** enormous progress has already been made in the field of equipment,then robot software depends on the development of artificial *** article proposes a solution for creating“logical”brains for autonomous robots,namely,an approach for creating an intelligent robot action planner based on Mivar expert *** application of this approach provides opportunities to reduce the computational complexity of solving planning problems and the requirements for the computational characteristics of hardware platforms on which intelligent planning systems are *** theoretically and practically justify the expediency of using logically solving systems,in particular Mivar expert systems,to create intelligent planners,the MIPRA(Mivar-based Intelligent Planning of Robot Actions)planner was created to solve problems such as STRIPS for permutation cubes in the Blocks World *** planner is based on the platform for creating expert systems of the *** a result,the Mivar planner can process information about the state of the subject area based on the analysis of cause-effect relationships and an algorithm for automatically constructing logical inference(finding a solution from“Given”to“Find”).Moreover,an important feature of the MIPRA is that the system is built on the principles of a“white box”,due to which the system can explain any of its decisions and provide justification for the actions performed in the form of a retrospective of the stages of the decision-making *** preparing a set of robot actions aimed at changing control objects,expert knowledge is used,which is the basis for the functioning algorithms of the *** approach makes it possible to include an expert in the process of organizing the work of the intelligent planner and use existing knowledge about the subject *** experiments of this study have shown that instead of many hours and powerfu

关键词： Autonomous robot blocks world decision-making system expert systems intelligent planning

DEM-CFD study of the filter cake formation process due to non-spherical particles

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Particuology 2020年第6期18卷 48-57页

作者： Ruturaj Deshpande Sergiy Antonyuk oleg Iliev Fraunhofer Institute for Industrial Mathematics ITWM KaiserslauternGermany Institute of Particle Process Engineering Technische Universitat KaiserslauternKaiserslauternGermany

The formation of a filter cake during the filtration of a suspension with non-spherical particles is studied using a multi-sphere model in a simulation that couples the discrete element method with computational fluid *** implementation of the coupling with a drag model that considers orientation,sphericity,and the presence of surrounding particles for non-spherical particles is tested for single particles and suspensions by comparing the terminal velocities with empirical *** predicted in the simulations,such as the presence or absence of initial oscillations and changes in the orientation of a particle,are consistent with experimental observations reported in the *** variation in the void fraction of a filter cake with respect to the particle sphericity is obtained and compared with experimental trends reported in the ***,complex interdependencies of the particle sphericity,void fraction,and pressure drop of a filter cake for a wide range of fluid conditions are investigated.

关键词： Filter cake formation Discrete element method-computational fluid dynamics simulation Non-spherical particles

Glycine-nitrate combustion engineering of neodymium cobaltite nanocrystals

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Rare Metals 2021年第7期40卷 1778-1784页

作者： Ekaterina Alekseevna Tugova oleg Nikolaevich Karpov New Inorganic Materials Laboratory Ioffe InstituteSaint-Petersburg 194021.Russia Department of Physical Chemistry Saint Petersburg Electrotechnical University“LETT”Saint-Petersburg 197376Russia

NdCoO_(3)nanocrystals formed via glycine-nitrate combustion method followed by heat treatment has been systematically *** of NdCoO_(3)nanocrystals with minimal size of 7-10 nm from X-ray amorphous combustion products has been elucidated to be a very rapid process,occurring at the temperature of 550-600℃for5-30 *** comparison of the minimum sizes of NdCoO_(3)crystallites obtained from the offered empirical relation dmin=lunit cell·N(where N is 7-12 and‘unit cellis elementary cell parameter)and the data determined on the basis of X-ray diffraction(XRD)and transmission electron microscopy(TEM)showed good *** existence of special nanoporous microstructure and spatial limitations prevent NdCoO_(3)particle *** kinetic equation based on Avrami-Erofeev nucleation model was offered to be correlated well with experimental data of fractional conversion(a)versus isothermal time(s).The apparent activation energy(Ea=(338±32)kJ)of formation of NdCoO_(3)nanocrystals from X-ray amorphous combustion products obtained in excess of oxidant followed by heat treatment at 550-600℃was determined.

关键词： Rare earths Perovskite Kinetics Mechanism Combustion synthesis Nucleation

Thermomechanical Energy Converters for Harvesting Thermal Energy:A Review

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Journal of Renewable Materials 2023年第4期11卷 1555-1600页

作者： oleg P.Dimitriev V.lashkaryov institute of semiconductor physics nas of ukrainekyiv03028ukraine

Thermal energy,i.e.,the electromagnetic energy in the infrared range that originates from the direct solar radiation,outgoing terrestrial radiation,waste heat from combustion of fuels,heat-emitting electrical devices,decay of radioactive isotopes,organic putrefaction and fermentation,human body heat,and so on,constitutes a huge energy flux circulating on the earth ***,most energy converters designed for the conversion of electromagnetic energy into electricity,such as photovoltaic cells,are mainly focused on using a narrow part of the solar energy lying in the visible spectrum,while thermomechanical engines that are fueled by heat in the broad energy range and then convert it into mechanical work or store it as mechanical deformation,are paid less *** the efficiency of thermomechanical devices is relatively low,they can be applied to collect waste heat which otherwise contributes to negative climate *** this review,operational principles of thermomechanical energy converters and a description of basic devices and materials that utilize thermal energy are *** addition to conventional macroscopic engines,based on thermoacoustic,thermomagnetic,thermoelastic,hydride heat converters,and shape memory alloys,the emergent devices are described which are classified as smart actuators,breathing frameworks,thermoacoustic micro-transducers,nanomechanical resonators,plasmomechanical systems,and optothermal *** performance of the different types of thermomechanical energy converters is described and compared.

关键词： Thermal energy smart actuator thermomechanical converter thermoelastic engine molecular machines emergent devices

Transverse magnetoresistance peculiarities of thermoelectric Lu-doped Bi_2Te_3 compound due to strong electrical disorder

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Journal of Rare Earths 2019年第3期37卷 292-298页

作者： oleg Ivanov Maxim Yaprintsev Elena Danshina Belgorod State University Belgorod State Technological University named after V.G.Shukhov

The n-type thermoelectric Bi_(1.9)Lu_(0.1)Te_3 was prepared by microwave-solvothermal method and spark plasma sintering. The magnetic field and temperature dependences of transverse magneto resistance measured within temperature 2-200 K interval allow finding the peculiarities characteristic for strongly disordered and inhomogeneous semiconductors. The first peculiarity is due to appearance of linear-inmagnetic field contribution to the total magneto resistance reflected in a crossover from quadratic magnetoresistance at low magnetic fields to linear magneto resistance at high magnetic fields. The linear magnetoresistance can result from the Hall resistance picked up from macroscopically distorted current paths due to local variations in stoichiometry of the compound studied. The second peculiarity is that both linear magnetoresistance magnitude and crossover field are functions of carrier mobility which is in agreement with the Parish and Littlewood model developed for disordered and inhomogeneous semiconductors. An increase in the mobility due to a decrease in temperature is accompanied by an increase in the magnetoresistance magnitude and a decrease in the crossover field. Finally, the third peculiarity is related to the remarkable deviation of the total magnetoresistance measured at various temperatures from the Kohler's rule. Presence of strong inhomogeneity and disorder in the Bi_(1.9)Lu_(0.1)Te_3 structure concluded from the magnetoresistance peculiarities can be responsible for the remarkable reduction in the total thermal conductivity of this compound.

关键词： Bismuth telluride Linear positive magnetoresistance Semiconductors Thermoelectric material Carrier mobility Kohler’s rule

Aerial multi-spectral AI-based detection system for unexploded ordnance

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Defence Technology（防务技术） 2023年第9期27卷 24-37页

作者： Seungwan Cho Jungmok Ma oleg A.Yakimenko Republic of Korea Army Republic of Korea/Defense Acquisition Program Administration47Gwanmun-roGwacheon-siGyeonggi-do13809Republic of Korea Department of Defense Science Korea National Defense University1040Republic of Korea Hwangsanbul-ro Yangchon-myeonNonsan-siChungcheongnam-do33021Republic of Korea Department of Systems Engineering Naval Postgraduate SchoolUSA 1 University Circle MontereyCA93943USA

Unexploded ordnance(UXO)poses a threat to soldiers operating in mission areas,but current UXO detection systems do not necessarily provide the required safety and efficiency to protect soldiers from this *** technological advancements in artificial intelligence(AI)and small unmanned aerial systems(sUAS)present an opportunity to explore a novel concept for UXO *** new UXO detection system proposed in this study takes advantage of employing an AI-trained multi-spectral(MS)sensor on *** paper explores feasibility of AI-based UXO detection using sUAS equipped with a single(visible)spectrum(SS)or MS digital electro-optical(EO)***,it describes the design of the Deep Learning Convolutional Neural Network for UXO detection,the development of an AI-based algorithm for reliable UXO detection,and also provides a comparison of performance of the proposed system based on SS and MS sensor imagery.

关键词： Unexploded ordnance(UXO) Multispectral imaging Small unmanned aerial systems(sUAS) Object detection Deep learning convolutional neural network(DLCNN)