The use of a model current wedge in the determination of the position of substorm current systems

Abstract. We present a technique for determination of the position and extent of the current systems present during substorm breakup. The parameters of a three-dimensional model of the currents are determined by fitting the model to data from the SAMNET magnetometer array, a midlatitude array of seven stations. The model used is a fully 3D current wedge aligned along dipolar field lines, the parameters being the meridians of upward and downward field-aligned currents (FACs), the latitude of the auroral electrojet and the magnitude of current growth over the observation interval. The method is novel in that the three geometrical parameters are first determined with the fourth arrived at via a secondary process. It has been applied to a number of events and appears to make estimates of the longitudes of the FACs consistent with the predictions of previous methods. Since the method employs a fully 3D model of the substorm current wedge as opposed to an idealised 2D model, it is reasonable to place more reliance on the results so obtained. Moreover, the method also has the additional benefit of a prediction of the latitude of the substorm electrojet and the nature of the current growth through the wedge at substorm onset.

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Intellectual Measuring Complex for Control of Geometrical Parameters of Aviation Details

Handbook of Research on Artificial Intelligence Applications in the Aviation and Aerospace Industries - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-7998-1415-3.ch015 ◽

2020 ◽

pp. 352-371

Author(s):

Mariia Kataieva ◽

Alina Yurchuk

Keyword(s):

Computer Simulation ◽

Measurement Error ◽

Three Dimensional ◽

Geometric Parameters ◽

Measurement Process ◽

Geometrical Parameters ◽

Automated Method ◽

Measuring Complex ◽

Graphic Depiction

This chapter proposes a new automated method of measuring complex three-dimensional surfaces of aircraft parts in static and dynamic modes. The method allows conducting measurements in closed conditions and at the site of the aircraft disposition. The method consists in the continuous determination of the coordinates of the points of the surface of the detail and their representation in a three-dimensional graphic depiction. New methods of measuring the geometric parameters of parts with the complex spatial surface are suggested. This opens the prospect for the development of new ways of measuring geometric parameters of parts in real-time with high metrological characteristics and computer simulation of the measurement process. The differential-digital method is based on the suggested zero-coordinate principle of the measurement process which involves simultaneous parts availability check, and connects measurement result obtained which provided a reduction in the order of measurement error.

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Conjugate Flow and Heat Transfer Investigation of a Turbo Charger: Part I — Numerical Results

Volume 3: Turbo Expo 2003 ◽

10.1115/gt2003-38445 ◽

2003 ◽

Cited By ~ 18

Author(s):

Dieter Bohn ◽

Tom Heuer ◽

Karsten Kusterer

Keyword(s):

Heat Transfer ◽

Three Dimensional ◽

Heat Fluxes ◽

Inlet Temperature ◽

Three Dimensional Model ◽

Flow And Heat Transfer ◽

Turbine Inlet ◽

Turbo Charger ◽

Conjugate Calculation

In this paper a three-dimensional conjugate calculation has been performed for a passenger car turbo charger. The scope of this work is to investigate the heat fluxes in the radial compressor which can be strongly influenced by the hot turbine. As a result of this, the compressor efficiency may deteriorate. Consequently, the heat fluxes have to be taken into account for the determination of the efficiency. To overcome this problem a complex three-dimensional model has been developed. It contains the compressor, the oil cooled center housing, and the turbine. 12 operating points have been numerically simulated composed of three different turbine inlet temperatures and four different mass flows. The boundary conditions for the flow and for the outer casing were derived from experimental test data (part II of the paper). Resulting from these conjugate calculations various one-dimensional calculation specifications have been developed. They describe the heat transfer phenomena inside the compressor with the help of a Nusselt number which is a function of an artificial Reynolds number and the turbine inlet temperature.

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Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds

Chemical and Process Engineering ◽

10.2478/v10176-011-0017-3 ◽

2011 ◽

Vol 32 (3) ◽

pp. 215-227 ◽

Cited By ~ 7

Author(s):

Paweł Jóźwik ◽

Michał Karcz ◽

Janusz Badur

Keyword(s):

Numerical Modelling ◽

Knudsen Diffusion ◽

Three Dimensional ◽

Operating Conditions ◽

Three Dimensional Model ◽

Toxic Compounds ◽

Slip Boundary ◽

Standard Models ◽

Thermocatalytic Decomposition

Numerical modelling of a microreactor for thermocatalytic decomposition of toxic compounds In this paper a three-dimensional model for determination of a microreactor's length is presented and discussed. The reaction of thermocatalytic decomposition has been implemented on the base of experimental data. Simplified Reynolds-Maxwell formula for the slip velocity boundary condition has been analysed and validated. The influence of the Knudsen diffusion on the microreactor's performance has also been verified. It was revealed that with a given operating conditions and a given geometry of the microreactor, there is no need for application of slip boundary conditions and the Knudsen diffusion in further analysis. It has also been shown that the microreactor's length could be practically estimated using standard models.

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A three-dimensional model to simulate joint networks in layered rocks

Canadian Journal of Earth Sciences ◽

10.1139/e02-043 ◽

2002 ◽

Vol 39 (10) ◽

pp. 1443-1455 ◽

Cited By ~ 15

Author(s):

Jean-Yves Josnin ◽

Hervé Jourde ◽

Pascal Fénart ◽

Pascal Bidaux

Keyword(s):

Fractured Rock ◽

Fractured Reservoirs ◽

Three Dimensional ◽

Geometrical Parameters ◽

Field Observations ◽

Three Dimensional Model ◽

Statistical Parameters ◽

Joint Spacing ◽

Fractal Approach ◽

Geometrical Properties

Modelling the discontinuity network of fractured reservoirs may be addressed (1) by purely stochastic means, (2) with a fractal approach, or (3) using mechanical parameters describing the spatial organisation of fracture systems. Our paper presents an approach where the geometrical properties of the fracture networks are incorporated in the form of both statistical and mechanical rules. This type of approach is particularly suitable to model stratified fractured rock masses comprising two orthogonal families of joints and a family of sedimentary discontinuities. Their geometrical arrangement is governed by two kinds of rules based on (1) statistical parameters such as the mean, standard deviation of joint length and of bed thickness, both determined by field observations, and (2) geometrical parameters that result from genetic processes inferred from field observations and analogue experiments on the nucleation and propagation mechanisms of joints. Using these parameters, we generate realistic networks in terms of the relative position of joints that control the overall network connectivity: the model enables all combinations of joint spacing and vertical persistence for orthogonal patterns ranging from ladder type to grid type patterns. It also integrates the concept of mechanical "saturation" of a bed, thereby permitting the generation of both "saturated" and "unsaturated" networks.

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The Parameters Optimization of Bionic Tongue Block Based on the Discrete Element Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.3298 ◽

2014 ◽

Vol 926-930 ◽

pp. 3298-3301

Author(s):

Li Chen ◽

Yong Hai Sun ◽

Yang Liu

Keyword(s):

Discrete Element Method ◽

Complex Structure ◽

Three Dimensional ◽

Discrete Element ◽

Parameters Optimization ◽

Tooth Surface ◽

Geometrical Parameters ◽

Three Dimensional Model ◽

Human Tongue ◽

Element Method

Human tongue has complex structure and involves in chewing function, such as transporting and mixing foods. In order to develop tongue block of the bionic chewing equipment to make the food materials slide from the lingual surface to the tooth surface as much as possible in the same time, three-dimensional model of tongue block was built according to the geometric shape and physiology characteristic of the human tongue. The discrete element method was used to simulate the whole delivery process of food materials to teeth area, and then the geometrical parameters of the tongue block were optimized. The simulated results showed that when the height of the tongue tip and the tongue root were fixed, the optimal slope angles which have the decisive effect on the process of food materials slide were 32°and 2° respectively. The results provided a theoretical basis for the processing of tongue block of the bionic chewing equipment.

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Generation of Novel-Substrate-Accepting Biphenyl Dioxygenases through Segmental Random Mutagenesis and Identification of Residues Involved in Enzyme Specificity

Applied and Environmental Microbiology ◽

10.1128/aem.72.3.2191-2199.2006 ◽

2006 ◽

Vol 72 (3) ◽

pp. 2191-2199 ◽

Cited By ~ 24

Author(s):

Marco Zielinski ◽

Silke Kahl ◽

Christine Standfuß-Gabisch ◽

Beatriz Cámara ◽

Michael Seeger ◽

...

Keyword(s):

Three Dimensional ◽

Random Mutagenesis ◽

Major Influence ◽

Enzyme Specificity ◽

Three Dimensional Model ◽

Wild Type Enzyme ◽

High Frequencies ◽

Burkholderia Xenovorans ◽

Function Relationship

ABSTRACT Aryl-hydroxylating dioxygenases are of interest for the degradation of persistant aromatic pollutants, such as polychlorobiphenyls (PCBs), or as catalysts for the functionalization of aromatic scaffolds. In order to achieve dioxygenation of technical mixtures of PCBs, enzymes with broadened or altered substrate ranges are essential. To alter the substrate specificity of the biphenyl dioxygenase (BphA) of Burkholderia xenovorans LB400, we applied a directed evolution approach that used structure-function relationship data to target random mutageneses to specific segments of the enzyme. The limitation of random amino acid (AA) substitutions to regions that are critical for substrate binding and the exclusion of AA exchanges from positions that are essential for catalytic activity yielded enzyme variants of interest at comparatively high frequencies. After only a single mutagenic cycle, 10 beneficial variants were detected in a library of fewer than 1,000 active enzymes. Compared to the parental BphA, they showed between 5- and 200-fold increased turnover of chlorinated biphenyls, with substituent patterns that rendered them largely recalcitrant to attack by BphA-LB400. Determination of their sequences identified AAs that prevent the acceptance of specific PCBs by the wild-type enzyme, such as Pro334 and Phe384. The results suggest prime targets for subsequent cycles of BphA modification. Correlations with a three-dimensional model of the enzyme indicated that most of the exchanges with major influence on substrate turnover do not involve pocket-lining residues and had not been predictable through structural modeling.

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КОМП’ЮТЕРНА ТЕХНОЛОГІЯ АНАЛІЗУ ТА ДИЗАЙНУ ПРЕДМЕТНОГО СЕРЕДОВИЩА З ПОЗИЦІЇ ВІЗУАЛЬНОГО СПРИЙНЯТТЯ

Art and Design ◽

10.30857/2617-0272.2020.2.3 ◽

2020 ◽

pp. 39-48

Author(s):

Т. В. Булгакова ◽

О. В. Полякова ◽

С. С. Кисіль ◽

О. Є. Шмельова

Keyword(s):

Visual Perception ◽

Quantitative Determination ◽

Three Dimensional ◽

Geometrical Model ◽

Human Being ◽

Dimensional Model ◽

Three Dimensional Model ◽

Three Dimensional Objects ◽

Computer Technologies

The purpose of the investigation is the development of computer technology of analysis and design of built environment from the point of its visual perception in the space of its three-dimensional model without using the perspective projections. The methodology were used to achieve the purpose: analysis of the scientific publications on the topic of object environment composition; applied geometry methods, method of division of the geometrical object into simplexes (triangulation), methods of advanced algebra and analytical geometry; computer modeling for construction of the model of visual perception of the environment. Methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed. It is offered to analyze the visual perception of any objects and their relations by means of using the solid angles with the vertices placed in the point of view and the surfaces that surround the visible contours of three-dimensional objects. This approach gives the opportunity to analyze the objects simultaneously regardless their position according to the observer; apart of that, the objects, which are accepted similarly in the reality, will have the same geometrical features during the modeling of visual perception and beside that, the refusal of using of the perspective projections will make possible to avoid the distortion of the images. The algorithm of determination of the solid angles to three-dimensional objects, which is the basis of computer methods of compositional analysis of the object environment from the position of visual perception without the use of perspective projections, is developed. The geometrical model of visual perception by a human being from the certain point of perception is built. It makes possible to define correctly visual features of the object environment and gives the opportunity to analyze the whole surrounding of the observer in the area of 360 degrees. Scientific novelty of the investigation means that the methods of analysis of the three-dimensional model on the basis of modeling of visual perception by means of computer technologies directly in the area of the model without using perspective projections are developed for the first time. The concept of the geometrical model of visual perception by a human being from the certain point of perception is developed. The further development of the methodology of quantitative determination of characteristics of object environment by means of computer technologies is defined. Practical significance shows that the results of the scientific investigation can be used for analysis and judgments of the aesthetic peculiarities of the object environment by means of computer technologies with quantitative determination of characteristics of object environment from the point of its visual perception. Such approach gives the opportunity to develop and create the further certain recommendations and instructions for correction of the existing environment and for the development of the new one.

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Synthesis of Three-Dimensional Models from Drawings Based on Spectral Graph Theory

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.756.598 ◽

2015 ◽

Vol 756 ◽

pp. 598-603 ◽

Cited By ~ 2

Author(s):

Aleksey Zakharov ◽

Arkady Zhiznyakov

Keyword(s):

Graph Theory ◽

Three Dimensional ◽

Spectral Graph Theory ◽

Boundary Representation ◽

Three Dimensional Model ◽

Three Dimensional Objects ◽

Spectral Graph ◽

Dimensional Models ◽

Three Dimensional Models

Task of automatic reconstruction of three-dimensional objects by drawing views presented. The algorithm based on a boundary representation of three-dimensional models. The algorithm consists of the following steps: automatic separation of the drawing per the views, determination of three-dimensional coordinates of vertices, definition and marking of wire model primitives, reconstruction of model faces and model elements. The fundamental concept of the algorithm is to find the structural elements of three-dimensional model with usage of pre-specified patterns. The templates are described by means of matrices. Matching algorithm uses spectral graph theory. Reconstruction results are presented.

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Creation of the substorm current wedge through the perturbation of the directly driven current system: a new model for substorm expansion

Annales Geophysicae ◽

10.5194/angeo-23-2171-2005 ◽

2005 ◽

Vol 23 (6) ◽

pp. 2171-2182 ◽

Cited By ~ 4

Author(s):

G. Rostoker ◽

E. Friedrich

Keyword(s):

Current System ◽

Three Dimensional ◽

Magnetospheric Substorms ◽

Substorm Current Wedge ◽

System A ◽

Storms And Substorms ◽

Auroral Phenomena ◽

Current Systems ◽

System Operating ◽

Current Wedge

Abstract. The past four decades have seen a considerable amount of research on the study of magnetospheric substorms, and over most of these years the expansive phase of the substorm has been associated with the development of a three dimensional current system that has been termed the substorm current wedge. This current system has been thought to be a consequence of the short-circuiting of crosstail current through the ionosphere, and is viewed as a distinctive current system operating independently from the directly driven current with which it co-exists. The purpose of this paper is to show that the substorm current wedge should be viewed as an equivalent current system rather than a real current system. It will be shown that the magnetic perturbation pattern associated with the current wedge can be modeled as purely a perturbation of the directly driven current system in the midnight sector. Keywords. Magnetospheric physics (Auroral phenomena; Current systems; Magnetotail; Storms and substorms

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