Modeling of uncertain environment based on multi-scale grid method

2012 ◽  
Author(s):  
Jianhui Zhao ◽  
Peng Jia ◽  
Shaobo Fu
Keyword(s):  
Grid Method ◽  
Uncertain Environment ◽  
Multi Scale ◽  
Scale Grid

scholarly journals Construction of multi-scale grid for massive land survey data

2020 ◽  
Vol 206 ◽  
pp. 03018
Author(s):  
Jia Zhang ◽  
Xiulian Wang ◽  
Xiaotong Zhang ◽  
Xiaofei Bai ◽  
Qiang Chen
Keyword(s):  
Information Integration ◽  
Data Model ◽  
Spatiotemporal Data ◽  
Distributed Data ◽  
Data Organization ◽  
Vector Data ◽  
Grid Data ◽  
Geospatial Information ◽  
Multi Scale ◽  
Scale Grid

In the face of ever-growing and complex massive multi-source spatiotemporal data, the traditional vector data model is increasingly difficult to meet the needs of efficient data organization, management, calculation and analysis. Based on the simple and widely used geographic grid data organization model, this paper designs a technical method to convert vector data into multi-scale grid data, establishes a unified, standardized and seamless land spatial grid data model, and analyses the area accuracy of multi-scale grid data. Practice shows that the model can better meet the needs of multi-scale geospatial information integration and analysis, and it is easy to carry out distributed data processing, which provides technical support for the efficient organization, fusion and analysis of spatiotemporal data.

Simulation of Liquid Jet Breakup of a Swirl-Type Fuel Injector for Automobile Engines

2007 ◽  
Author(s):  
Eiji Ishii ◽  
Toru Ishikawa ◽  
Yoshiyuki Tanabe
Keyword(s):  
Water Column ◽  
Grid Method ◽  
Particle Method ◽  
Engine Fuel ◽  
Fuel Injector ◽  
Free Surfaces ◽  
Scale Free ◽  
Multi Scale ◽  
Jet Breakup ◽  
Automobile Engines

To simulate multi-scale free surfaces, we developed a hybrid particle/grid method by which the free surfaces within sub-grid regions are simulated by the particle method, and other regions are simulated with the grid method. The particle method uses two types of particles to model gas and liquid fluids in order to simulate the interaction between them. We tested the new method on fragmentation of a water column, and the predicted configurations of the water column are consistent with measurements of Koshizuka and Oka. We also simulated the fuel spray near the outlet of an automobile-engine fuel injector and found that this method qualitatively simulated the breakup of the liquid film.

227 Spatial development and decay characteristic of turbulence generated by fractal, classical, multi-scale grid

2016 ◽  
Vol 2016.65 (0) ◽  
pp. _227-1_-_227-2_
Author(s):  
Teppei SAIKI ◽  
Koji NAGATA ◽  
Yasuhiko SAKAI ◽  
Yasumasa ITO ◽  
Koji IWANO
Keyword(s):  
Spatial Development ◽  
Decay Characteristic ◽  
Multi Scale ◽  
Scale Grid

scholarly journals Defocused image restoration method based on micro-nano scale

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Yongjun Liu ◽  
Qiuyu Wu ◽  
Mingxin Zhang ◽  
Yi Wang
Keyword(s):  
Image Restoration ◽  
Enhancement Effect ◽  
Multi Scale ◽  
Nano Scale ◽  
Adaptive Noise ◽  
Restoration Method ◽  
Defocused Image ◽  
Optical Defocus ◽  
Scale Grid

An image adaptive noise reduction enhancement algorithm based on NSCT is proposed to perform image restoration preprocessing on the defocused image obtained under the microscope. Defocused images acquired under micro-nano scale optical microscopy, usually with inconspicuous details, edges and contours, affect the accuracy of subsequent observation tasks. Due to its multi-scale and multi-directionality, the NSCT transform has superior transform functions and can obtain more textures and edges of images. Combined with the characteristics of micro-nanoscale optical defocus images, the NSCT inverse transform is performed on all sub-bands to reconstruct the image. Finally, the experimental results of the standard 500nm scale grid, conductive probe and triangular probe show that the proposed algorithm has a better image enhancement effect and significantly improves the quality of out-of-focus images.

Study of Factors Influencing Non-Uniform Gas-Liquid Distribution in the Refrigerant Distributor in an Air Conditioner

2014 ◽  
Author(s):  
Eiji Ishii ◽  
Kazuki Yoshimura
Keyword(s):  
Grid Method ◽  
Particle Method ◽  
Liquid Films ◽  
Gas Flows ◽  
Air Conditioner ◽  
Liquid Interfaces ◽  
Liquid Distribution ◽  
Air Conditioners ◽  
Multi Scale ◽  
Liquid Flows

Factors that influence the non-uniform gas-liquid distribution in refrigerant distributors in air conditioners were studied. Gas-liquid flows in two-pass and multi-pass distributors were numerically simulated with a particle/grid hybrid method; droplets and liquid films were mainly simulated using a particle method, and gas flows were simulated using a grid method. Complex behaviors of multi-scale gas-liquid interfaces in the multi-pass distributor were simulated because droplets that were smaller than the grid size could be simulated without numerical diffusion through the gas-liquid interfaces. The effect of the connecting angle of the bend pipe was studied in the two-pass distributor, whereas the effects of the tube’s position relative the distributor inflow and the effect of gravity were investigated in the multi-pass distributor. The model was validated against multiple experimental data taken from an at-scale physical model. We found that keeping the liquid at the inlets of the multi-pass tubes was important for ensuring a uniform distribution.

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