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A theory to link relationships of stand volume,density,mean diameter and height in forestry data

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Journal of Forestry Research 2021年第1期32卷 15-20页

作者： vladimir L.Gavrikov Chair of Ecology and Environmental Studies Institute Ecology and GeographySiberian Federal University79 pr.SvobodnyiKrasnoyarskRussian Federation 660041

In this study,a geometric model of a growing forest stand has been *** basic relationships considered link stand volume and stand density,diameter at breast height(DBH),mean DBH and mean *** model provides simple formulas connecting the exponents of all the *** of the formulas to real forestry data provided a high level of predictions of an exponent from two others measured through regressions from empirical *** Pinus sylvestris *** were of a static nature,a collection of individual stands,while the Pseudotsuga menziesii(Mirb.)Franco data were dynamic,representing forest stand development over *** ability of the model to predict exponents in the empirical data implies,on the one hand,a substantial level of similarity between the model and the forestry ***,on the other hand,the model gives an example in which parameters of one relationship may be linked to parameters of *** this kind of‘relationship between relationships’may be observed in forest stands undergoing active growth and competition-induced self-thinning.

关键词： Relationship between relationships Selfthinning Forestry data Allometry Scots pine Douglasfir

Equilibrium Arrivals to Preemptive Queueing System with Fixed and Random Population Size

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Journal of the Operations Research Society of China 2024年第1期12卷 77-92页

作者： Julia Chirkova vladimir Mazalov Institute of Applied Mathematical Research Karelian Research Centre of RASPetrozavodsk185910Russia School of Mathematics and Statistics Qingdao UniversityQingdao266071ShandongChina

A single-server queueing system with preemptive access is *** customer has one attempt to enter the system at its working interval[0,T].As soon as the customer request enters the system,the server immediately starts the *** when the next request arrives in the system,the previous one leaves the system even he has not finished his service *** study a non-cooperative game in which the customers wish to maximize their probability of obtaining service within a certain period of *** characterize the Nash equilibrium and the price of anarchy,which is defined as the ratio between the optimal and equilibrium social *** models are *** the first model the number of players is fixed,while in the second it is random and obeys the Poisson *** demonstrate that there exists a unique symmetric equilibrium for both ***,we calculate the price of anarchy for both models and show that the price of anarchy is not monotone with respect to the number of customers.

关键词： Service system Preemptive priorities Strategic users Random number of players Optimal arrivals Kolmogorov backward equations Nash equilibrium Price of anarchy

Impact of normal stress-induced closure on laboratory-scale solute transport in a natural rock fracture

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第4期12卷 732-741页

作者： Liangchao Zou vladimir Cvetkovic Division of Resources Energy and InfrastructureDepartment of Sustainable DevelopmentEnvironmental Science and EngineeringRoyal Institute of TechnologyStockholm10044Sweden Department of Physical Geography Stockholm UniversityStockholm10691Sweden

The impact of normal stress-induced closure on fluid flow and solute transport in a single rock fracture is demonstrated in this *** fracture is created from a measured surface of a granite rock *** Bandis model is used to calculate the fracture closure due to normal stress,and the fluid flow is simulated by solving the Reynold *** Lagrangian particle tracking method is applied to modeling the advective transport in the *** results show that the normal stress significantly affects fluid flow and solute transport in rock *** causes fracture closure and creates asperity contact areas,which significantly reduces the effective hydraulic aperture and enhances flow ***,the reduced aperture and enhanced channeling affect travel time *** particular,the enhanced channeling results in enhanced first arriving and tailing behaviors for solute *** fracture normal stiffness correlates linearly with the 5th and 95th percentiles of the normalized travel *** finding from this study may help to better understand the stress-dependent solute transport processes in natural rock fractures.

关键词： Normal stress Fluid flow Solute transport Stiffness Particle tracking

Stability of the Liquid-Vapor Interface under the Combined Influence of Normal Vibrations and an Electric Field

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Fluid Dynamics & Materials Processing 2024年第11期20卷 2541-2563页

作者： vladimir Konovalov Institute of Continuous Media Mechanics The Ural Branch of RASPerm614000Russia

The regime of horizontal subcooled film boiling is characterized by the formation of a thin layer of vapor coveringthe surface of a flat horizontal heater. Based on the equations of motion of a viscous incompressible fluid and theequation of heat transfer, the stability of such a vapor film is investigated. The influence of the modulation of thegravity field caused by vertical vibrations of the heater of finite frequency, as well as a constant electric fieldapplied normal to the surface of the heater, is taken into account. It is shown that in the case of a thick vaporfilm, the phase transition has a little effect on the thresholds for the occurrence of parametric instability in thesystem and its transformation into the most dangerous one. At the same time, the electric field contributes toan increase in these thresholds. It was found that the effect of vibrations on the stabilization of non-parametricinstability in the system is possible only in a narrow region of the parameter space where long-wave damped disturbances exist and consists of reducing the critical heat flux of stabilization. A vapor film stabilized in this waycan be destroyed due to the development of parametric instability. In contrast to the case of a thick vapor layer,the threshold for the onset of parametric instability for thin films largely depends on the value of subcooling in thesystem. In addition, this threshold decreases with increasing electric field strength. For a vapor film ten micronsthick, the instability threshold can be reduced by a factor of three or more by applying an electric field of aboutthree million volts per meter.

关键词： Film boiling subcooling phase transition vibrations electricfield

On finite 2-groups all of whose subgroups are mutually isomorphic

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Science China Mathematics 2009年第2期52卷 254-260页

作者： EPULIC vladimir Faculty of Electrical Engineering and Computing University of Zagreb

In this paper we investigate the title groups which we call isomaximal. We give the list of all isomaximal 2-groups with abelian maximal subgroups. Further, we prove some properties of isomaximal 2-groups with nonabelian maximal subgroups. After that, we investigate the structure of isomaximal groups of order less than 64. Finally, in Theorem 14. we show that the minimal nonmetacyclic group of order 32 possesses a unique isomaximal extension of order 64.

关键词： p-groups maximal subgroups minimal nonabelian minimal nonmetacyclic 20D15

Example-based dynamic façade design using the façade daylighting performance improvement(FDPI)indicator

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Building Simulation 2023年第12期16卷 2261-2283页

作者： Luka Akimov Andrey Bezborodov vladimir Badenko Peter the Great Saint-Petersburg Polytechnic University 29 Polytechnicheskaya st.St.Petersburg195251Russian Federation Politecnico di Milano 32 Piazza Leonardo da VinciMilano20133Italy

It remains challenging to conduct an efficient dynamic façade *** this article authors try to address this issue introducing the façade daylighting performance improvement(FDPI)indicator aimed to evaluate the performance of a dynamic(adaptive)façade from its daylighting performance point of *** illustrate the FDPI application the authors introduced the preliminary dynamic façade concept for an office building located in Tel Aviv(Hot-summer Mediterranean Climate Csa)with further shape modification based on the daylighting performance analysis compared to the three alternatives representative of different typologies of dynamic faç*** Bahr,One Ocean and The University of Southern Denmark façade systems were simulated under the same weather and building conditions of the preliminary dynamic façade concept and were considered as a benchmark for the *** final dynamic façade concept elaborated by the authors in the preliminary comparative workflow showed noticeable daylight performance improvement with respect to the case studies comparative *** FDPI metric allowed to estimate a daylighting performance improvement of 43%of the final dynamic façade concept over the case study dynamic façade that showed the best performance in the daylighting simulations.

关键词： dynamic façade adaptive façade daylight performance performance evaluation façade daylighting performance Improvement

Powerful terahertz waves from long-wavelength infrared laser filaments

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Light(Science & Applications) 2020年第1期9卷 204-219页

作者： vladimir Yu.Fedorov Stelios Tzortzakis Science Program Texas A&M University at QatarP.O.Box 23874DohaQatar P.N.Lebedev Physical Institute of the Russian Academy of Sciences 53 Leninskiy ProspektMoscow 119991Russia Institute of Electronic Structure and Laser(IESL) Foundation for Research and Technology-Hellas(FORTH)P.O.Box 1527Heraklion GR-71110Greece Department of Materials Science and Technology University of CreteHeraklion GR-71003Greece

Strong terahertz(THz)electric and magnetic transients open up new horizons in science and *** review the most promising way of achieving sub-cycle THz pulses with extreme field *** the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses,long,and thick plasma strings are produced,where strong photocurrents result in intense THz *** corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels,*** intensities of these THz fields enable extreme nonlinear optics and relativistic *** offer a comprehensive review,starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses,the theoretical and numerical advances in the nonlinear propagation of these laser fields,and the most important experimental demonstrations to date.

关键词： laser extreme optics

The non-Gaussian distribution of galaxy gravitational fields

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Research in Astronomy and Astrophysics 2017年第12期17卷 1-14页

作者： vladimir Stephanovich Wlodzimierz Godlowski Uniwersytet Opolski Institute of Physicsul.Oleska 4845-052 OpolePoland

We perform a theoretical analysis of the observational dependence between angular momentum of galaxy clusters and their mass（richness）, based on the method introduced in our previous *** that we obtain the distribution function of gravitational fields for astronomical objects（like galaxies and/or smooth halos of different kinds） due to their tidal interaction. By applying the statistical method of Chandrasekhar, we are able to show that the distribution function is determined by the form of interaction between objects and for multipole（tidal） interaction it is never Gaussian. Our calculation permits demonstrating how the alignment of galaxy angular momenta depends on cluster richness. The specific form of the corresponding dependence is due to assumptions made about cluster morphology. Our approach also predicts the time evolution of stellar object angular momenta within CDM and ΛCDM models. Namely, we have shown that angular momentum of galaxies increases with time.

关键词： galaxies:general galaxies:formation

Some Limit Theorems for a Particle System of Single Point Catalytic Branching Random Walks

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Acta Mathematica Sinica,English Series 2007年第6期23卷 997-1012页

作者： vladimir VATUTIN Jie XIONG Steklov Mathematical Institute Gubkin street 8 119991 Moscow Russia Department of Mathematics University of Tennessee Knoxville TN 37996 1300 USA Department of Mathematics Hebei Normal University Shijiazhuang 050016 P. R. China

We study the scaling limit for a catalytic branching particle system whose particles perform random walks on Z and can branch at 0 only. Varying the initial （finite） number of particles, we get for this system different limiting distributions. To be more specific, suppose that initially there are n^β particles and consider the scaled process Zt^n（·） = Znt（√n·）, where Zt is the measure-valued process 1 and to a representing the original particle system. We prove that Ztn converges to 0 when β 〈1/4 and to a nondegenerate discrete distribution when β=1/*** addition,if 1/4〈β〈1/2 then n-^（2β-1/2）Zt^n converges to a random limit,while if β 〉21then n^-βZtn converges to a deterministic limit.

关键词： Renewal equation branching particle system scaling limit