scholarly journals A Study of Modified Infotaxis Algorithms in 2D and 3D Turbulent Environments

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shurui Fan ◽  
Dongxia Hao ◽  
Xudong Sun ◽  
Yusuf Mohamed Sultan ◽  
Zirui Li ◽  
...  
Keyword(s):  
Rapid Development ◽  
Three Dimensional ◽  
Evaluation Criteria ◽  
Research Field ◽  
Sensor Data ◽  
Sensor Technology ◽  
Two Dimensional ◽  
Reward Function ◽  
Autonomous Search ◽  
Hazardous Gas

Emergency response to hazardous gases in the environment is an important research field in environmental monitoring. In recent years, with the rapid development of sensor technology and mobile device technology, more autonomous search algorithms for hazardous gas emission sources are proposed in uncertain environment, which can avoid emergency personnel from contacting hazardous gas in a short distance. Infotaxis is an autonomous search strategy without a concentration gradient, which uses scattered sensor data to track the location of the release source in turbulent environment. This paper optimizes the imbalance of exploitation and exploration in the reward function of Infotaxis algorithm and proposes a mobile strategy for the three-dimensional scene. In two-dimensional and three-dimensional scenes, the average steps of search tasks are used as the evaluation criteria to analyze the information trend algorithm combined with different reward functions and mobile strategies. The results show that the balance between the exploitation item and exploration item of the reward function proposed in this paper is better than that of the reward function in the Infotaxis algorithm, no matter in the two-dimensional scenes or in the three-dimensional scenes.

Sensor Data Geographic Forwarding in Two-Dimensional and Three-Dimensional Spaces

2017 ◽  
pp. 317-352
Author(s):  
Habib M. Ammari ◽  
Amer Ahmed
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Three Dimensional ◽  
Geographic Routing ◽  
Sensor Nodes ◽  
Sensor Data ◽  
Wireless Sensor ◽  
Two Dimensional ◽  
Geographic Forwarding ◽  
Limited Power

A wireless sensor network is a collection of sensor nodes that have the ability to sense phenomena in a given environment and collect data, perform computation on the gathered data, and transmit (or forward) it to their destination. Unfortunately, these sensor nodes have limited power, computational, and storage capabilities. These factors have an influence on the design of wireless sensor networks and make it more challenging. In order to overcome these limitations, various power management techniques and energy-efficient protocols have been designed. Among such techniques and protocols, geographic routing is one of the most efficient ways to solve some of the design issues. Geographic routing in wireless sensor networks uses location information of the sensor nodes to define a path from source to destination without having to build a network topology. In this paper, we present a survey of the existing geographic routing techniques both in two-dimensional (2D) and three-dimensional (3D) spaces. Furthermore, we will study the advantages of each routing technique and provide a discussion based on their practical possibility of deployment.

3-D Video Enhancemnt Based on Histogram Equalization and Edge Sharpening

2013 ◽  
Vol 333-335 ◽  
pp. 1129-1133 ◽  
Author(s):  
Yi Min Qiu ◽  
Shi Hong Chen ◽  
Yi Zhou ◽  
Ying Wang
Keyword(s):  
Stereo Vision ◽  
Three Dimensional ◽  
Subjective Assessment ◽  
Histogram Equalization ◽  
Research Field ◽  
Experimental Results ◽  
Two Dimensional ◽  
Video Mode ◽  
Equalization Method ◽  
Edge Sharpening

With the development of stereo vision, much more attention has paid from two-dimensional to three-dimensional (3-D) spaces, research on 3-D image/video becomes an inevitable trend presently. We present a novel research field that focused on the enhancement of 3-D videos, using two different 3-D videos and enhancing them with histogram equalization and edge sharpening algorithms. And we utilize the subjective assessment in the experiments. The experimental results show that the edge sharpening method has better effect than the histogram equalization method in 3-D video mode. But we also find some problems that both methods have blurred edges.

Synthetic aperture diffraction tomography for three-dimensional imaging

2009 ◽  
Vol 465 (2109) ◽  
pp. 2877-2895 ◽  
Author(s):  
Francesco Simonetti ◽  
Lianjie Huang
Keyword(s):  
World War Ii ◽  
High Resolution ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Sensor Technology ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Theoretical Formulation ◽  
Three Dimensional Objects ◽  
Aperture Diffraction

Tomography of complex three-dimensional objects with ultrasound or microwave has been a long-standing goal since the introduction of these technologies after World War II. While current state-of-the-art systems can provide high-resolution images of cylindrical objects characterized by a two-dimensional structure, the three-dimensional case remains an open challenge owing to current limitations of sensor technology and computer power. Here, this problem is addressed by means of a synthetic aperture technique that, while using hardware technology developed for two-dimensional problems, accounts for the complexity of three-dimensional scattering and leads to high-resolution three-dimensional reconstructions. In this paper, we present the theoretical formulation of this new approach and illustrate it by means of a numerical example.

Sensor Data Geographic Forwarding in Two-Dimensional and Three-Dimensional Spaces

2020 ◽  
pp. 1459-1493
Author(s):  
Habib M. Ammari ◽  
Amer Ahmed
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Three Dimensional ◽  
Geographic Routing ◽  
Sensor Nodes ◽  
Sensor Data ◽  
Wireless Sensor ◽  
Two Dimensional ◽  
Geographic Forwarding ◽  
Limited Power

A wireless sensor network is a collection of sensor nodes that have the ability to sense phenomena in a given environment and collect data, perform computation on the gathered data, and transmit (or forward) it to their destination. Unfortunately, these sensor nodes have limited power, computational, and storage capabilities. These factors have an influence on the design of wireless sensor networks and make it more challenging. In order to overcome these limitations, various power management techniques and energy-efficient protocols have been designed. Among such techniques and protocols, geographic routing is one of the most efficient ways to solve some of the design issues. Geographic routing in wireless sensor networks uses location information of the sensor nodes to define a path from source to destination without having to build a network topology. In this paper, we present a survey of the existing geographic routing techniques both in two-dimensional (2D) and three-dimensional (3D) spaces. Furthermore, we will study the advantages of each routing technique and provide a discussion based on their practical possibility of deployment.

Application on the Virtual Campus Making with 3D Max and VRP Technology

2013 ◽  
Vol 753-755 ◽  
pp. 1295-1298
Author(s):  
Hui Ying Zhao ◽  
Li Bo Qiu ◽  
You Ming Liu ◽  
Qi Feng ◽  
Zhi Yong Huang ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Rapid Development ◽  
Three Dimensional ◽  
Computer Software ◽  
Two Dimensional ◽  
Virtual Reality Technology ◽  
Virtual Campus ◽  
Campus Environment ◽  
Angle Rotation ◽  
Software And Hardware

With the rapid development of computer software and hardware technology, 3D technology and virtual reality technology is acquiring a greater growing space. Three-dimensional virtual campus environment compared with the traditional two-dimensional campus graphics more intuitive, vivid, true-to-life. More convenient to operate, you can choose a different camera pan any, the viewpoint conversion, angle rotation.

scholarly journals Two- and three-dimensional wake transitions of an impulsively started uniformly rolling circular cylinder

2017 ◽  
Vol 826 ◽  
pp. 32-59 ◽  
Author(s):  
F. Y. Houdroge ◽  
T. Leweke ◽  
K. Hourigan ◽  
M. C. Thompson
Keyword(s):  
Stability Analysis ◽  
Circular Cylinder ◽  
Rapid Development ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Instability Modes ◽  
Two Dimensional Flow ◽  
Lift And Drag

This paper presents the characteristics of the different stages in the evolution of the wake of a circular cylinder rolling without slipping along a wall at constant speed, acquired through numerical stability analysis and two- and three-dimensional numerical simulations. Reynolds numbers between 30 and 300 are considered. Of importance in this study is the transition to three-dimensionality from the underlying two-dimensional periodic flow and, in particular, the way that the associated transitions influence the fluid forces exerted on the cylinder and the development and the structure of the wake. It is found that the steady two-dimensional flow becomes unstable to three-dimensional perturbations at $Re_{c,3D}=37$, and that the transition to unsteady two-dimensional flow – or periodic vortex shedding – occurs at $Re_{c,2D}=88$, thus validating and refining the results of Stewart et al. (J. Fluid Mech. vol. 648, 2010, pp. 225–256). The main focus here is on Reynolds numbers beyond the transition to unsteady flow at $Re_{c,2D}=88$. From impulsive start up, the wake almost immediately undergoes transition to a periodic two-dimensional wake state, which, in turn, is three-dimensionally unstable. Thus, the previous three-dimensional stability analysis based on the two-dimensional steady flow provides only an element of the full story. Floquet analysis based on the periodic two-dimensional flow was undertaken and new three-dimensional instability modes were revealed. The results suggest that an impulsively started cylinder rolling along a surface at constant velocity for $Re\gtrsim 90$ will result in the rapid development of a periodic two-dimensional wake that will be maintained for a considerable time prior to the wake undergoing three-dimensional transition. Of interest, the mean lift and drag coefficients obtained from full three-dimensional simulations match predictions from two-dimensional simulations to within a few per cent.

scholarly journals 3D Perception of Maximum Density Zone on Ramachandran Plots for Zika Virus Protein Structures

2016 ◽  
Author(s):  
Mayukh Mukhopadhyay ◽  
Parama Bhaumik
Keyword(s):  
Zika Virus ◽  
Rapid Development ◽  
Protein Structures ◽  
Three Dimensional ◽  
Small Region ◽  
Virus Protein ◽  
Two Dimensional ◽  
True Nature ◽  
Data Points ◽  
Ramachandran Plots

AbstractThe Ramachandran plot is among the most central concepts in structural biology which uses torsion angles to describe polypeptide and protein conformation. To help visualize the features of high-fidelity Ramachandran plots, it is helpful to look beyond the common two-dimensional psi-phi-plot, which for a large dataset does not serve very well to convey the true nature of the distribution. In particular, when a large subset of the observations is found very narrowly distributed within one small region, this is not well seen in the simple plot because the data points congest one another. Zika Virus (ZIKV) protein databank has been chosen as specimen for analysis. This is because the structure, tropism, and pathogenesis of ZIKV are largely unknown and are the focus of current investigations in an effort to address the need for rapid development of vaccines and therapeutics. After a brief survey on Zika Virus, it is shown that when a dense dataset of ZIKV protein databank is passed through a colour-coded scaled algorithm, a three dimensional plot gets generated which gives a much more compelling impression of the proportions of residues in the different parts of the protein rather than representing it in a normal two dimensional psi-phi plot.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

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