scholarly journals Boundary element model of the human head exposed to an electrostatic field generated by Video Display Units

2008 ◽  
Author(s):  
D. Čavka ◽  
D. Poljak ◽  
A. Peratta ◽  
C. Brebbia
Keyword(s):  
Boundary Element ◽  
Electrostatic Field ◽  
Human Head ◽  
Element Model ◽  
Video Display ◽  
Video Display Units

scholarly journals Comparison Between Finite and Boundary Element Methods for Analysis of Electrostatic Field Around Human Head Generated by Video Display Units

2011 ◽  
Vol 7 (1) ◽  
pp. 22 ◽  
Author(s):  
Damir Čavka ◽  
Dragan Poljak ◽  
Andres Peratta
Keyword(s):  
Finite Element ◽  
Boundary Element ◽  
Electrostatic Field ◽  
Computational Efficiency ◽  
Scalar Potential ◽  
Mathematical Formulation ◽  
Human Head ◽  
Boundary Element Methods ◽  
Video Display ◽  
Video Display Units

Boundary and finite element modeling approach to the assessment of electrostatic field on human head generated by Video Display Units (VDU’s) are compared and discussed. Attention is focused to the field distribution over the surface of the face. The mathematical formulation for the assessment of the electrostatic field is based on the Laplace equation for the electric scalar potential. The electrostatic field is calculated for two different models of face. Numerical results are presented and compared in order to estimate the accuracy and computational efficiency of the two methods for the considered problem. In order to make comparison as meaningful as possible, boundaryand finite element codes have been both developed by theauthors. In general, boundary element appears to be the better choice than finite element with respect to computational efficiency and level of accuracy.

A New Computer Simulation of Neck Injury Biomechanics

2011 ◽  
Vol 467-469 ◽  
pp. 339-344
Author(s):  
Na Li ◽  
Jian Xin Liu
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Head And Neck ◽  
Traffic Accidents ◽  
Ethical Issues ◽  
Human Head ◽  
Element Model ◽  
Neck Injury ◽  
Element Analysis ◽  
Injury Mechanisms

Head and neck injuries are the most frequent severe injury resulting from traffic accidents. Neck injury mechanisms are difficult to study experimentally due to the variety of impact conditions involved, as well as ethical issues, such as the use of human cadavers and animals. Finite element analysis is a comprehensive computer aided mathematical method through which human head and neck impact tolerance can be investigated. Detailed cervical spine models are necessary to better understand cervical spine response to loading, improve our understanding of injury mechanisms, and specifically for predicting occupant response and injury in auto crash scenarios. The focus of this study was to develop a C1–C2 finite element model with optimized mechanical parameter. The most advanced material data available were then incorporated using appropriate nonlinear constitutive models to provide accurate predictions of response at physiological levels of loading. This optimization method was the first utilized in biomechanics understanding, the C1–C2 model forms the basis for the development of a full cervical spine model. Future studies will focus on tissue-level injury prediction and dynamic response.

scholarly journals Investigation of Low-Sidelobe Beampattern Controlling Methods for Acoustic Transmitting Array of Underwater Vehicles

2017 ◽  
Vol 24 (s2) ◽  
pp. 103-110
Author(s):  
Zhengyao He ◽  
Qiang Shi ◽  
Shaoxuan Wu
Keyword(s):  
Boundary Element ◽  
Element Model ◽  
Optimization Method ◽  
Underwater Vehicles ◽  
Unmanned Vehicles ◽  
Driving Voltage ◽  
Sound Waves ◽  
Low Sidelobe ◽  
Acoustic Transducer ◽  
Weighting Vector

Abstract In underwater unmanned vehicles, complex acoustic transducer arrays are always used to transmitting sound waves to detect and position underwater targets. Two methods of obtaining low-sidelobe transmitting beampatterns for acoustic transmitting arrays of underwater vehicles are investigated. The first method is the boundary element model optimization method which used the boundary element theory together with the optimization method to calculate the driving voltage weighting vector of the array. The second method is the measured receiving array manifold vector optimization method which used the measured receiving array manifold vectors and optimization method to calculate the weighting vector. Both methods can take into account the baffle effect and mutual interactions among elements of complex acoustic arrays. Computer simulation together with experiments are carried out for typical complex arrays. The results agree well and show that the two methods are both able to obtain a lower sidelobe transmitting beampattern than the conventional beamforming method, and the source level for each transmitting beam is maximized in constraint of the maximum driving voltage of array elements being constant. The effect of the second method performs even better than that of the first method, which is more suitable for practical application. The methods are very useful for the improvement of detecting and positioning capability of underwater unmanned vehicles.

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