scholarly journals A harmonic spectral beamformer for the enhanced localization of propeller-driven aircraft

2019 ◽  
Vol 7 (2) ◽  
pp. 156-174 ◽  
Author(s):  
Brendan Harvey ◽  
Siu O’Young
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Frequency Domain ◽  
Search Algorithm ◽  
Target Localization ◽  
Acoustic Source ◽  
Localization Technique ◽  
Localization Accuracy ◽  
Standard Frequency ◽  
Processing Techniques

The following paper presents several array processing techniques that may be used to enhance the localization of acoustic source targets, such as UAVs. A review of common methods is first provided, followed by several algorithms developed to reduce computational loads for the application of concern. A beamforming method is proposed that exploits the properties of harmonic narrowband signals, such as that generated by propeller-driven aircraft to enhance direction of arrival accuracy. In addition, a regional contraction search algorithm is proposed to minimize computational loads associated with the presented localization technique. A brief comparison of the proposed method to that of standard frequency domain beamformers is also provided using both theoretical analysis and experimental data. For the case of target localization between two moving fixed-wing UAVs, it was found that the proposed harmonic spectral beamforming method increased localization accuracy by 50% over the standard steered response power approach.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Method of Optimization for Target Localization Model Parameters Based on LSSVR

2011 ◽  
Vol 268-270 ◽  
pp. 934-939
Author(s):  
Xue Wen He ◽  
Gui Xiong Liu ◽  
Hai Bing Zhu ◽  
Xiao Ping Zhang
Keyword(s):  
Particle Swarm Optimization ◽  
Fitness Function ◽  
Particle Swarm ◽  
Parameters Optimization ◽  
Target Localization ◽  
Likelihood Method ◽  
Support Vector ◽  
Swarm Optimization ◽  
Localization Accuracy ◽  
Localization Method

Aiming at improving localization accuracy in Wireless Sensor Networks (WSN) based on Least Square Support Vector Regression (LSSVR), making LSSVR localization method more practicable, the mechanism of effects of the kernel function for target localization based on LSSVR is discussed based on the mathematical solution process of LSSVR localization method. A novel method of modeling parameters optimization for LSSVR model using particle swarm optimization is proposed. Construction method of fitness function for modeling parameters optimization is researched. In addition, the characteristics of particle swarm parameters optimization are analyzed. The computational complexity of parameters optimization is taken into consideration comprehensively. Experiments of target localization based on CC2430 show that localization accuracy using LSSVR method with modeling parameters optimization increased by 23%~36% in compare with the maximum likelihood method(MLE) and the localization error is close to the minimum with different LSSVR modeling parameters. Experimental results show that adapting a reasonable fitness function for modeling parameters optimization using particle swarm optimization could enhance the anti-noise ability significantly and improve the LSSVR localization performance.

A Dynamic Test of Fully Prestressed Concrete Beams

2011 ◽  
Vol 368-373 ◽  
pp. 2483-2490
Author(s):  
Yao Ting Zhang ◽  
Yi Zheng ◽  
Hong Jian Li
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Theoretical Analysis ◽  
Natural Frequency ◽  
Axial Force ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Dynamic Test ◽  
Modified Formula

A dynamic test of two unbonded fully prestressed concrete beams has been conducted. The results indicate that the natural frequency of beams increases with the prestress force, which is opposite to the analytical arguments for homogeneous and isotropic beams subject to axial force. This paper explains the change in frequencies by discussing the change in the elastic modulus. A modified formula is also proposed, and the experimental data agree well with the theoretical analysis.

scholarly journals Comparative analysis of methods to determine deflection in steel beams: theoretical analysis, finite element and experimental

2020 ◽  
pp. 32-37
Author(s):  
Gabriela Alor-Saavedra ◽  
Francisco Alejandro Alaffita-Hernández ◽  
Beatris Adriana Escobedo-Trujillo ◽  
Oscar Fernando Silva-Aguilar
Keyword(s):  
Differential Equation ◽  
Experimental Data ◽  
Finite Element ◽  
Comparative Analysis ◽  
Theoretical Analysis ◽  
Comparative Study ◽  
Steel Beams ◽  
Physical Systems ◽  
Theoretical Part ◽  
Made In

This work makes a comparative study of two methods to determine deflection in steel beams: (a) Theoretical and (b) Finite element. For method (a) the solution of the differential equation associated with the modeling of the deflection of a beam is found, while for method (b) a simulation is made in Solidworks. Both methods are compared with experimental data in order to analyze which of the methods presents less uncertainty and show the usefulness of the theoretical part in the modeling of physical systems.

scholarly journals Wave Propagation in Thin-Walled Aortic Analogues

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
C. G. Giannopapa ◽  
J. M. B. Kroot ◽  
A. S. Tijsseling ◽  
M. C. M. Rutten ◽  
F. N. van de Vosse
Keyword(s):  
Experimental Data ◽  
Wave Propagation ◽  
Frequency Domain ◽  
Analytical Model ◽  
Viscoelastic Properties ◽  
Numerical Models ◽  
Computational Cost ◽  
One Dimensional ◽  
Arterial Blood

Research on wave propagation in liquid filled vessels is often motivated by the need to understand arterial blood flows. Theoretical and experimental investigation of the propagation of waves in flexible tubes has been studied by many researchers. The analytical one-dimensional frequency domain wave theory has a great advantage of providing accurate results without the additional computational cost related to the modern time domain simulation models. For assessing the validity of analytical and numerical models, well defined in vitro experiments are of great importance. The objective of this paper is to present a frequency domain analytical model based on the one-dimensional wave propagation theory and validate it against experimental data obtained for aortic analogs. The elastic and viscoelastic properties of the wall are included in the analytical model. The pressure, volumetric flow rate, and wall distention obtained from the analytical model are compared with experimental data in two straight tubes with aortic relevance. The analytical results and the experimental measurements were found to be in good agreement when the viscoelastic properties of the wall are taken into account.

Impact analysis of attitude determination accuracy to target localization accuracy on Multi-BD receivers

2016 ◽  
Vol 31 (9) ◽  
pp. 902-912
Author(s):  
蔡明兵 CAI Ming-bing ◽  
王超 WANG Chao ◽  
刘晶红 LIU Jing-hong ◽  
周前飞 ZHOU Qian-fei ◽  
宋悦铭 SONG Yue-ming
Keyword(s):  
Impact Analysis ◽  
Attitude Determination ◽  
Target Localization ◽  
Localization Accuracy

Evaluation of patient‐specific MR distortion correction schemes for improved target localization accuracy in SRS

2020 ◽  
Author(s):  
Dimitrios Dellios ◽  
Eleftherios P. Pappas ◽  
Ioannis Seimenis ◽  
Chryssa Paraskevopoulou ◽  
Kostas I. Lampropoulos ◽  
...  
Keyword(s):  
Distortion Correction ◽  
Target Localization ◽  
Patient Specific ◽  
Localization Accuracy
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