scholarly journals Ultimate Fast Gyrosynchrotron Codes

2021 ◽  
Vol 922 (2) ◽  
pp. 103
Author(s):  
Alexey A. Kuznetsov ◽  
Gregory D. Fleishman
Keyword(s):  
Distribution Function ◽  
Pitch Angle ◽  
Three Dimensional ◽  
Computation Time ◽  
Single Spectrum ◽  
Practical Applications ◽  
Three Dimensional Modeling ◽  
Analytical Functions ◽  
Astrophysical Objects ◽  
Gyrosynchrotron Emission

Abstract The past decade has seen a dramatic increase in practical applications of microwave gyrosynchrotron emission for plasma diagnostics and three-dimensional modeling of solar flares and other astrophysical objects. This breakthrough became possible due to an apparently minor, technical development of fast gyrosynchrotron codes, which enormously reduced the computation time needed to calculate a single spectrum, while preserving the accuracy of the computation. However, the available fast codes are limited in that they can only be used for a factorized distribution over the energy and pitch angle, while the distribution of electrons over energy or pitch angle is limited to a number of predefined analytical functions. In realistic simulations, these assumptions do not hold; thus, the codes free from the mentioned limitations are called for. To remedy this situation, we extended our fast codes to work with an arbitrary input distribution function of radiating electrons. We accomplished this by implementing fast codes for a distribution function described by an arbitrary numerically defined array. In addition, we removed several other limitations of the available fast codes and improved treatment of the free–free component. The ultimate fast codes presented here allow for an arbitrary combination of the analytically and numerically defined distributions, which offers the most flexible use of the fast codes. We illustrate the code with a few simple examples.

AUTOMATIC THREE‐DIMENSIONAL MODELING FOR THE INTERPRETATION OF GRAVITY OR MAGNETIC ANOMALIES

Geophysics ◽  
1975 ◽  
Vol 40 (6) ◽  
pp. 1014-1034 ◽  
Author(s):  
A. Gerard ◽  
N. Debeglia
Keyword(s):  
Distribution Function ◽  
Fourier Transform ◽  
Iterative Method ◽  
Three Dimensional ◽  
Magnetic Anomalies ◽  
Average Depth ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
The Fourier Transform ◽  
Homogeneous Media

Transformation of gravity or magnetic anomaly maps into isodepth maps of a surface separating two homogeneous media may be accomplished by (1) systematically estimating an average depth and density or magnetization contrast for the surface and (2) using an iterative method to adjust local depths compared to the average depth of the surface. Average depth, density or magnetization contrast, and iterative adjustment of local depths are determined using the Fourier transform of the field to be interpreted and that of the field generated by an equivalent surface. This leads us to propose a method of estimating the average depth of the sources and a distribution function for the depths and then a complete and very economical algorithm for the calculation of the corresponding equivalent surface.

Image Method With Distributed Multipole Models for Analyzing Permanent-Magnet-Based Electromagnetic Actuators

2008 ◽  
Author(s):  
Kok-Meng Lee ◽  
Hungsun Son ◽  
Kun Bai
Keyword(s):  
Permanent Magnets ◽  
Three Dimensional ◽  
Computation Time ◽  
Image Method ◽  
Maximum Torque ◽  
Electromagnetic Actuators ◽  
Maxwell Stress Tensor ◽  
Practical Applications ◽  
Electromagnetic Problems ◽  
Force Equation

Many high-torque electromagnetic problems involve solving three dimensional (3D) magnetic fields of the permanent magnets (PMs) and/or electromagnet magnets (EMs) in the presence of magnetically conducting surfaces. This paper extends the distributed multi-pole (DMP) method, which offers a means to present the three-dimensional magnetic field solution in closed form, to account for the effects of the magnetic conducting boundary using an image method. We validate the DMP/image method by comparing the torques calculated using the Lorentz force equation and Maxwell stress tensor against numerical results computed using a finite element method (FEM). While two methods agree to within 5% in maximum torque, the DMP/image method takes less than 1% of the FEM computation time. With the numerically validated torque computation, we demonstrate how the DMP/image method can be used to analyze designs of a spherical wheel motor as illustrative practical applications.

A Three-Dimensional Modeling of Multidirectional Random Wave Interactions by Multiple Rectangular Submarine Pits

2004 ◽  
Author(s):  
Hong Sik Lee ◽  
A. Neil Williams ◽  
Sung Duk Kim
Keyword(s):  
Numerical Model ◽  
Velocity Potential ◽  
Three Dimensional ◽  
Boundary Integral ◽  
Integral Approach ◽  
Random Wave ◽  
Random Surface ◽  
Directional Spectrum ◽  
Practical Applications ◽  
Three Dimensional Modeling

A three-dimensional numerical model is presented to predict the interactions of multidirectional random surface waves with one or more rectangular submarine pits. The water depth in the fluid region exterior to the pits is taken to be uniform. The three-dimensional Green function in the boundary integral equation, obtained by Green’s second identity, has been used for the solution of the velocity potential and its derivative in fluid interface between regions, and also a form of the Fourier expansion is utilized for the solution of the velocity potential in the interior region. The incident wave conditions are specified using a discrete form of the Mitsuyasu directional spectrum. The present method is based on the cumulative superposition of linear diffraction solutions obtained by a three-dimensional boundary integral approach. The results of the present model have been compared with those of previous theoretical studies for both regular and random wave diffraction by single or multiple pits. Reasonable agreement was consistently obtained in all cases. In accordance with good agreement from these comparisons, it is concluded that the present numerical model may accurately be utilized to predict the three-dimensional wave field around multiple submarine pits or navigation channels in many practical applications.

Design and Simulation of Tobacco Harvesting System Based on Virtual Manufacturing Technology

2012 ◽  
Vol 522 ◽  
pp. 736-739
Author(s):  
Jun Liu ◽  
Wen Kui Ma
Keyword(s):  
Information Integration ◽  
Manufacturing Industry ◽  
Design Method ◽  
Three Dimensional ◽  
Virtual Manufacturing ◽  
Motion Simulation ◽  
Three Dimensional Model ◽  
Practical Applications ◽  
Three Dimensional Modeling ◽  
Comprehensive Development

Virtual manufacturing reflects the nature of manufacturing in the computer implementation. It is the comprehensive development and application of computer simulation technology and virtual reality technology in manufacturing. It is also a new concept in manufacturing industry, for which enterprises use information integration as bases. This article therefore describes the practical applications of the tobacco harvesting in virtual manufacturing system. Based on the whole to part-based design idea, we adopt a brand new design method which uses the interaction of three-dimensional design, graphic design and partial tests. Meanwhile, it uses soliderworks software to create three-dimensional modeling and motion simulation for the tobacco harvesting system. Specifically, for the design part, we first conduct the constraint and connecting assembly of the established three-dimensional model of the tobacco harvest system to form an entirety. Then we carry on the motion simulation tests, which show the kinetic characteristics of the system in the virtual environment. The final step is data processing and error modification. The result indicates that this method not only improves the accuracy and efficiency of design manufacturing and reduces relevant costs, but also improves the collection level of the leaf tobacco harvesting machine, reduces harvesting costs with a relative high value.

Dependence of the Deformation of 128×128 InSb Focal-plane Arrays on the Silicon Readout Integrated Circuit Thickness

2015 ◽  
Vol 9 (1) ◽  
pp. 170-174 ◽  
Author(s):  
Xiaoling Zhang ◽  
Qingduan Meng ◽  
Liwen Zhang
Keyword(s):  
Thermal Shock ◽  
Indium Antimonide ◽  
Integrated Circuit ◽  
Focal Plane ◽  
Three Dimensional ◽  
Fracture Probability ◽  
Focal Plane Arrays ◽  
Thermal Shock Test ◽  
Readout Integrated Circuit ◽  
Three Dimensional Modeling

The square checkerboard buckling deformation appearing in indium antimonide infrared focal-plane arrays (InSb IRFPAs) subjected to the thermal shock tests, results in the fracturing of the InSb chip, which restricts its final yield. In light of the proposed three-dimensional modeling, we proposed the method of thinning a silicon readout integrated circuit (ROIC) to level the uneven top surface of InSb IRFPAs. Simulation results show that when the silicon ROIC is thinned from 300 μm to 20 μm, the maximal displacement in the InSb IRFPAs linearly decreases from 7.115 μm to 0.670 μm in the upward direction, and also decreases linearly from 14.013 μm to 1.612 μm in the downward direction. Once the thickness of the silicon ROIC is less than 50 μm, the square checkerboard buckling deformation distribution presenting in the thicker InSb IRFPAs disappears, and the top surface of the InSb IRFPAs becomes flat. All these findings imply that the thickness of the silicon ROIC determines the degree of deformation in the InSb IRFPAs under a thermal shock test, that the method of thinning a silicon ROIC is suitable for decreasing the fracture probability of the InSb chip, and that this approach improves the reliability of InSb IRFPAs.

Three-dimensional Graphene Coated Shape Memory Polyurethane Foam with Fast Responsive Performance

2021 ◽  
Author(s):  
Tianjiao Wang ◽  
Jun Zhao ◽  
Chuanxin Weng ◽  
Tong Wang ◽  
Yayun Liu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Polyurethane Foam ◽  
Three Dimensional ◽  
Shape Memory Polymers ◽  
Practical Applications ◽  
External Stimuli ◽  
Shape Memory Polyurethane

Shape memory polymers (SMPs) that change shapes as designed by external stimuli have become one of the most promising materials as actuators, sensors, and deployable devices. However, their practical applications...

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