37 research outputs found
Oil and Gas Exploration Planning using VOI Technique
Paper deals with actual problem about making decisions during field development. The main aim was to apply method "Value of information" in order to estimate the necessity of field exploration works and show the effectiveness of this method. The object of analysis - field X, which is located in the Eastern Siberia. The reservoir is B13 formation of Vend age. The Field has complex structure, and divided into blocks by faults. During evaluation of the project, main uncertainties and oil in place were obtained for three blocks of the field. According to uncertainty analysis, it was suggested to drill a new exploration well, and value of information method was applied to estimate results from this exploration works. Economic evaluation of the value of information method was made by choosing optimal development strategy. According to the obtained results, drilling of the exploration wells for blocks 1 and 3 of the field X is a good decision, while drilling a well in the second block is risky and not recommended. Also using the value of information, optimal well locations were advised - well l_le for the first block, and well 3_3 for the third block
Oil and Gas Exploration Planning using VOI Technique
Paper deals with actual problem about making decisions during field development. The main aim was to apply method "Value of information" in order to estimate the necessity of field exploration works and show the effectiveness of this method. The object of analysis - field X, which is located in the Eastern Siberia. The reservoir is B13 formation of Vend age. The Field has complex structure, and divided into blocks by faults. During evaluation of the project, main uncertainties and oil in place were obtained for three blocks of the field. According to uncertainty analysis, it was suggested to drill a new exploration well, and value of information method was applied to estimate results from this exploration works. Economic evaluation of the value of information method was made by choosing optimal development strategy. According to the obtained results, drilling of the exploration wells for blocks 1 and 3 of the field X is a good decision, while drilling a well in the second block is risky and not recommended. Also using the value of information, optimal well locations were advised - well l_le for the first block, and well 3_3 for the third block
Transmission of vortex electrons through a solenoid
We argue that it is generally nonstationary Laguerre-Gaussian states (NSLG)
rather than the Landau ones that appropriately describe electrons with orbital
angular momentum both in their dynamics at a hard-edge boundary between a
solenoid and vacuum and inside the magnetic field. It is shown that the r.m.s.
radius of the NSLG state oscillates in time and its period-averaged value can
significantly exceed the r.m.s. radius of the Landau state, even far from the
boundary. We propose to study the unconventional features of quantum dynamics
inside a solenoid in several experimental scenarios with vortex electrons
described by the NSLG states. Relevance for processes in scanning and
transmission electron microscopes, as well as for particle accelerators with
relativistic beams is emphasized.Comment: 6 pages, 2 figure
СИНТЕЗ ОПТИМАЛЬНОГО УПРАВЛЕНИЯ ВОЗДУШНЫМ СУДНОМ НА ОСНОВЕ УРАВНЕНИЙ НЕЛИНЕЙНОЙ ДИНАМИКИ
The article considers the technique of the synthesis of non-linear aircraft control systems by flight optimization us- ing inverse dynamics problems. To synthesize control algorithms a non-linear model of aircraft flight and trajectory movement is used. The authors define method stages of flying level synthesis which include: selection of aircraft reference movements in accordance with three degrees of freedom, structuring the control algorithms and their parameters, defining the proximity of current and reference movements by means of a quadratic functional and further extremum-minimum movement organization by the gradient method. Through the optimized parameters of flying level the direct dynamics problem of trajectory level control of the aircraft spatial movement is solved. The basis for calculating the aircraft trajecto- ry parameters is a non-linear model of the trajectory movement for which flying level output parameters serve as input data. The trajectory level output parameters are defined by numerical integration of input signals considering aircraft dynamic blow coefficients. The structure diagram of aircraft spatial movement control organization is developed. The flight contour functioning is examined using numerical modeling in MathCad and Paskal programs. Reference parameters were determined by Paskal simulation modeling according to the reaction of a non-linear aircraft model to the “bounces” of aerody- namical flight controls. It is shown that the spatial control problem is optimal in terms of input control realization. Besides, in comparison with [9] it is possible to state that due to energy reversibility of rotational and progressive movements only the content of direct and inversed problems of dynamics changes.В статье рассматривается методика синтеза нелинейных систем управления воздушным судном (ВС) на основе оптимизации пилотажного контура по методу обратных задач динамики. Для синтеза алгоритмов управления применяется нелинейная математическая модель движения ВС на пилотажном и траекторном уровнях. Определены этапы методики синтеза на пилотажном уровне, включающие: назначение эталонных движений ВС по трем степеням свободы, выбор структуры алгоритмов управления и их параметров, определение степени близости текущего и эталонного движений с помощью квадратичного функционала с последующей организацией движения к экстремуму-минимуму градиентным методом. Через оптимизируемые параметры пилотажного уровня решается прямая задача динамики для траекторного уровня управления пространственным движением ВС. Основой для выполнения расчета траекторных параметров ВС является нелинейная математическая модель траекторного движения, входом для которого служат выходные параметры пилотажного уровня. При этом выходные параметры траекторного уровня определяются путем численного интегрирования входных сигналов с учетом динамических обдувочных коэффициентов ВС. Разработана структурная схема организации контуров управления пространственным движением ВС. Выполнено исследование функционирования пилотажного контура путем численного моделирования с использованием программ MathCad и Паскаль. Параметры эталонной модели определялись путем имитационного моделирования на языке Паскаль по реакции нелинейной модели ВС на ступенчатые отклонения аэродинамических рулей. Показано, что задача управления пространственным движением оптимальна в смысле реализации управляющего воздействия. Кроме того, в сравнении с [9] можно утверждать, что из-за обратимости преобразований энергий вращательного и поступательного движений изменяется только содержание прямых и обратных задач динамики
ВЗРЫВ КОЛЬЦЕВОГО ЗАРЯДА НА ЗАПЫЛЕННОЙ ПОВЕРХНОСТИ
This problem is related to the safety problem in the area of forest fires. It is well known that is possible to extinguish a fire, for example, by means of a powerful air stream. Such flow arises from the explosive shock wave. To enhance the im- pact of the blast wave can be used an explosive charge of annular shape. The shock wave, produced by the explosion, in- creased during moves to the center and can serve as a means of transportation dust in the seat of the fire. In addition, emerging after the collapse of a converging shock wave strong updraft can raise dust on a greater height and facilitate fire extinguishing, precipitating dust over a large area. This updraft can be dangerous for aircraft that are in the sky above the fire. To determine the width and height of the danger zone performed the numerical simulation of the ring of the explosion and the subsequent movement of dust and gas mixtures. The gas is considered ideal and perfect. The explosion is modeled as an instantaneous increase in the specific internal energy in an annular zone on the value of the specific heat of explosives. The flow is consid- ered as two-dimensional, and axisymmetric. The axis of symmetry perpendicular to the Earth surface. This surface is considered to be absolutely rigid and is considered as the boundary of the computational domain. On this surface is exhibited the condition of no motion. For the numerical method S. K. Godunov is used a movable grid. One system of lines of this grid is moved in accordance with movement of the shock wave. Others lines of this grid are stationary. The calculations were per- formed for different values of the radii of the annular field and for different sizes of rectangular cross-sectional of the annular field. Numerical results show that a very strong flow is occurring near the axis of symmetry and the particles rise high above the surface. These calculations allow us to estimate the sizes of the zone of danger in specific situations.Рассматриваемая задача связана с проблемой безопасности полетов в зоне лесных пожаров. Известно, что прекратить пожар можно, сбив пламя, например, мощным потоком воздуха. Такой поток возникает за взрывной ударной волной. Естественно предположить, что для усиления воздействия взрывной волны можно использовать заряд взрывчатого вещества кольцевой формы. Ударная волна, возникающая при взрыве такого заряда, должна усиливаться по мере движения к центру и может служить средством транспортировки ингибирующей пыли в очаг пожара. Кроме того, возникающий после схлопывания сходящейся ударной волны сильный восходящий поток сможет поднять пыль на большую высоту и способствовать гашению пламени осаждающимся ингибитором на большой площади. Этот восходящий поток может оказаться опасным для летательных аппаратов, находящихся в небе над пожаром. Для выяснения ширины и высоты опасной для полетов зоны проводится численное моделиро- вание кольцевого взрыва и последующих за этим движений пылегазовых смесей. Газ считается идеальным и со- вершенным. Взрыв моделируется мгновенным повышением удельной внутренней энергии в кольцевой области на величину удельного тепловыделения взрывчатого вещества. Течение рассматривается как двумерное и осесиммет- ричное. Для описания движения неравновесной пылегазовой смеси в рамках модели взаимопроникающих конти- нуумов используются уравнения Эйлера в цилиндрической системе координат. Ось симметрии перпендикулярна поверхности, которая считается абсолютно жесткой и является границей расчетной области. На ней выставляется условие непротекания. Для численных расчетов используется метод С.К. Годунова с движущейся сеткой и явным выделением головной ударной волны в качестве границы зоны вычисления. Одна система линий расчетной сетки перемещается в соответствии с движением этой ударной волны, а другая остается неподвижной. Расчеты проведе- ны при различных величинах радиусов кольцевой области и размеров ее прямоугольного поперечного сечения. Численные результаты показывают, что кумуляция потока происходит вблизи оси симметрии, и в результате силь- ная ударная волна распространяется вверх вдоль оси симметрии, и частицы поднимаются высоко над поверхно- стью. Эти расчеты позволяют оценить для типичных ситуаций размеры опасной зоны
Biorealistic Response in Optoelectrically-Driven Flexible Halide-Perovskite Single-Crystal Memristors
The transition to smart wearable and flexible optoelectronic devices
communicating with each other and performing neuromorphic computing at the edge
is a big goal in next-generation optoelectronics. These devices should perform
their regular tasks supported by energy-efficient in-memory calculations. Here,
we study the response of the CsPbBr halide-perovskite single crystal
fabricated on the flexible polymer substrate and integrated with the
single-walled carbon nanotube thin film electrodes in a lateral geometry. We
show both photodetection functions combined with the synaptic functionality in
our device under the application of hybrid optoelectrical stimuli. Furthermore,
we demonstrate that our device exhibits frequency-dependent bidirectional
modification of synaptic weight with a sliding threshold similar to
biologically plausible Bienenstock-Cooper-Munro learning. The demonstrated
optoelectronic synaptic behavior in halide-perovskite single-crystals opens the
opportunity for the development of hybrid organic-inorganic artificial visual
systems
MODEL OF EVALUATING THE LEVEL OF PARASITIC PHASE FLUCTUATIONS IN THE OUTPUT SIGNAL OF THE FREQUENCIES SYNTHESIZER
The article describes the actual problem of calculating the level of parasitic fluctuations of the phase of the output signal of the frequency synthesizer of indirect synthesis based on phase-locked loop. The basis for constructing a polynomial model is the model of output noise distribution based on the Leeson generator principle. The described principles of operation of frequency synthesizers with a divider with a fractionally variable division factor allow us to understand the nature of the appearance of the so-called shot noise. The analysis of the characteristics of all the elements included in the frequency synthesizers makes it possible to ensure that the noise components of each individual unit can be represented as a polynomial. The possibility of using the developed polynomial model for estimating the noise level in frequency synthesizers at the stage of selecting the structure of the proposed implementation structure is proposed. As a demonstration of the adequacy of theoretical calculations, the results of phase noise simulation by the polynomial method for all circuit components are presented, as well as a comparison of the results obtained with the simulation of a similar frequency synthesizer in the «ADIsimPLL» simulation package from Analog Devices. Such a simulation allows not only to obtain the level of side components in the spectrum of the output signal, but also to estimate the degree of influence of each specific element of the circuit
Method of determining the coordinates of the radio signal source in satellite communication systems
Telecommunications have penetrated deeply into all spheres of human activity. Due to the use of digital technologies, it has become possible to transmit and receive information of various kinds in one stream (not separately). Three geostationary satellites are sufficient to provide data transmission from anywhere in the world to another point using artificial Earth satellites. Data transmission systems using the satellite should contain at least two Earth Stations and a repeater of the communication satellite. There are no means of combating any types of artificial interference in the Earth Stations equipment. The jammer, an illegitimate user, can emit a signal from any point in space within a telecommunications satellite system. The paper provides an analysis of existing methods for determining the coordinates of a radio signal source, describes a method for determining the coordinates of an radio signal source (illegitimate user) in satellite telecommunications systems using a geostationary spacecraft. The development was based on a three-position virtual antenna array, the positions of which determined the base of an irregular tetrahedron, and the radio signal source itself was its vertex. In the course of the solution, canonical equations of straight lines in space were compiled, at the intersection point of which the source of the radio signal is located. The coordinates of the radio signal source were the roots of the system, when finding the unit vectors lying on these lines