423 Hits in 6.0 sec

Multiple Object Localization in Underwater Wireless Communication Systems using the Theory of Gravitation

Ruhul Amin Khalil, Nasir Saeed, Tariqullah Jan, Majid Ashraf
2018 2018 25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP)  
The proposed algorithm is based on collective utilization of gravity field vector and gravity gradient tensor signals for object localization.  ...  Localization of underwater objects has always been a challenging task due to the unguided and misty nature of the underwater environment.  ...  Techniques known as gravity field vectors (GFV) and gravity gradient tensor (GGT) have been recently developed, to locate and monitor movements of various objects in aerial and underwater environments.  ... 
doi:10.1109/m2vip.2018.8600876 dblp:conf/m2vip/KhalilSJA18 fatcat:e6tjrv7d3vesffmzbeo32xv2oq

Historical development of the gravity method in exploration

M. N. Nabighian, M. E. Ander, V. J. S. Grauch, R. O. Hansen, T. R. LaFehr, Y. Li, W. C. Pearson, J. W. Peirce, J. D. Phillips, M. E. Ruder
2005 Geophysics  
This and the advent of  ...  In oil exploration the gravity method is particularly applicable in salt provinces, overthrust and foothills belts, underexplored basins, and targets of interest that underlie high-velocity zones.  ...  The remaining components of the gravity gradient tensor are constructed from Laplace's equation and the symmetry of the tensor.  ... 
doi:10.1190/1.2133785 fatcat:ko2mmwhu7nccvchod6kwfhppfy

An overview of sensing platform-technological aspects for vector magnetic measurement: a case study of the application in different scenarios [article]

Huan Liu, Haobin Dong, Jian Ge, Zheng Liu
2021 arXiv   pre-print
In this case, the vector magnetic survey method can simultaneously obtain the modulus and direction information of the Earth's magnetic field, which can effectively reduce the multiplicity on data inversion  ...  , contribute to the quantitative interpretation of the magnetic body and obtain more precise information and characteristics of magnetic field resource, so as to improve the detection resolution and positioning  ...  gradient tensor with the help of triaxial SQUID magnetometers placed near the probe.  ... 
arXiv:2007.05198v2 fatcat:cqlfngr4yjfwrga7o6r56efd6e

Underwater square-root cubature attitude estimator by use of quaternion-vector switching and geomagnetic field tensor

Huang Yu, Wu Lihua, Yu Qiang
2020 Journal of Systems Engineering and Electronics  
The filter formulation is based on geomagnetic field tensor measurement dependent on the attitude and a gyro-based model for attitude propagation.  ...  This paper presents a kind of attitude estimation algorithm based on quaternion-vector switching and square-root cubature Kalman filter for autonomous underwater vehicle (AUV).  ...  Measurement of the field gradient or tensor delivers more geological details than a scalar measurement of a single component or of the scalar total magnetic intensity.  ... 
doi:10.23919/jsee.2020.000055 fatcat:nmmhrc7zdvg4xaalorgqrpyuo4

Report of the Geodetic Works in Japan for the Period from January 2015 to December 2018

2019 Journal of the Geodetic Society of Japan  
The Shimosato Hydrographic Observatory of the Japan Coast Guard has been carrying out satellite laser ranging observation since 1982 and shared data with the International Laser Ranging Service (ILRS).  ...  Jike and Tamura (2017) reported the result of the geodetic VLBI experiments which VERA conducted in 2015 and 2016, and the 2015 and 2016 biennial status of geodetic observation equipment.  ...  Sawada (2016): Continuity, segmentation and faulting type of active fault zones of the 2016 Kumamoto earthquake inferred from analyses of a gravity gradient tensor, Earth, Planets and Space, 68, 167, doi  ... 
doi:10.11366/sokuchi.65.19 fatcat:pw3epkybavgepg6dphzc24rxai

Theoretical treatment of fluid flow for accelerating bodies

Irvy M. A. Gledhill, Hamed Roohani, Karl Forsberg, Peter Eliasson, Beric W. Skews, Jan Nordström
2016 Theoretical and Computational Fluid Dynamics  
These expressions should be in a form that allows terms to be transformed between non-inertial and inertial frames, and includes gravity, viscous terms, and linear and angular acceleration.  ...  With the advent of sharp manoeuvre, which may lead to transient effects originating in the acceleration of the centre of mass, there is a need to have a consistent formulation of the Navier-Stokes equations  ...  Gledhill wishes to acknowledge with gratitude the joint project set up by the CSIR that made this work possible, and the great hospitality of the University of the Witwatersrand School of Mechanical, Industrial  ... 
doi:10.1007/s00162-016-0382-0 fatcat:drvk2qcu5rhjxaetzklsxa66vu

Direct numerical simulation of cylindrical particle-laden gravity currents

N. Zgheib, T. Bonometti, S. Balachandar
2015 Computers & Fluids  
We present results from direct numerical simulations (DNS) of cylindrical particle-laden gravity currents.  ...  Our results are in good agreement with previously reported experiments and theoretical models.  ...  The two anonymous reviewers are thanked for their detailed and insightful comments which greatly improved the quality of the paper.  ... 
doi:10.1016/j.compfluid.2015.09.001 fatcat:nk2ciqcdxzf55jdnhmwebe3q4y

Theta phase coding in a network model of the entorhinal cortex layer II with entorhinal-hippocampal loop connections

Jun Igarashi, Hatsuo Hayashi, Katsumi Tateno
2006 Cognitive Neurodynamics  
This model is rather abstract, and the several layers of the hippocampus and the entorhinal cortex were modeled by simple oscillator units to describe local field theta rhythms.  ...  For instance, a vector is a 1-way tensor, a matrix is a 2-way tensor, and a cube is a 3-way tensor, etc.  ...  We verified the fundamental operation of two coupled element circuits with HSPICE. The results demonstrated that the circuits synchronized with in-and anti-phase depending on coupling strengths.  ... 
doi:10.1007/s11571-006-9003-8 pmid:19003510 pmcid:PMC2267667 fatcat:avihqfr6a5e7tm43lythi27n3a

Quantum Sensing and Metrology [chapter]

2021 Law and Policy for the Quantum Age  
The next three chapters build on quantum sensing by explaining the history of quantum computing, its likely uses, and the current landscape of the field.  ...  and more efficient and targeted mineral extraction. Quantum sensors are also a precursor for quantum computers and communications.  ...  SQUIDs can detect the strength and gradient of magnetic fields, and since electrical current creates a magnetic field, SQUIDs can be used for non-invasive imaging of the human body. 11 In the medical field  ... 
doi:10.1017/9781108883719.006 fatcat:ev7luvp5creltfa7s4k44th4ma

Videotapes and Movies on Fluid Dynamics and Fluid Machines [chapter]

Bobbie Carr, Virginia E. Young
2009 Handbook of Fluid Dynamics and Fluid Machinery  
by gradients of surface tension due to impurities, temperature gradients, and electric fields.  ...  in the earth's gravity field and in the centrifugal field of a rotating fluid mass, and shapes of isobaric and isochoric surfaces.  ... 
doi:10.1002/9780470172643.ch17 fatcat:xjrdnepiqnfmdmlaqweyk2pl44

Correlation of radon and geomagnetic anomalies of the territory of Ukraine
Зв'язок радонових та геомагнітних аномалій території України

M.I. Orlyuk, A.V. Marchenko, P.I. Yatsevsky
2018 Natsional'na Akademiya Nauk Ukrainy. Dopovidi: naukovyi zhurnal  
The structure of the IAEA Nuclear Energy Series comprises three levels: 1 -Basic Principles and Objectives; 2 -Guides; and 3 -Technical Reports.  ...  Under the terms of Articles III.A and VIII.C of its Statute, the IAEA is authorized to foster the exchange of scientific and technical information on the peaceful uses of atomic energy.  ...  Gradient measurements can be taken with two sensors mounted vertically with a separation distance of 0.5 to 1 m. Data can be reported as a gradient of the magnetic field in nT/m.  ... 
doi:10.15407/dopovidi2018.05.060 fatcat:s4ajey2265f7zmqlpbrgdot6ra

A geometrical approach to the motion planning problem for a submerged rigid body

Ryan N. Smith, Monique Chyba, George R. Wilkens, Christopher J. Catone
2009 International Journal of Control  
The equations of motion are formulated and presented by use of the framework of differential geometry and these equations incorporate external dissipative and restoring forces.  ...  This method is of particular interest to autonomous underwater vehicles which can not directly control all six degrees of freedom (such as torpedo shaped AUVs) or in case of actuator failure (i.e., under-actuated  ...  These interactions come in the form of control inputs, buoyancy gravity, pressure gradients and friction, among others. These are characterized as forces.  ... 
doi:10.1080/00207170802654410 fatcat:cyqbrufhy5gtlb7fw4eqst2scy

Hydrodynamic Model of Diver–DPV Coupled Multi-Body and Its Underwater Cruising Numerical Simulation

Hansheng Li, Fenglei Han, Haitao Zhu, Jiawei Zhang, Weipeng Zhang, Yuliang Wu
2021 Journal of Marine Science and Engineering  
Five cases of DPVs underwater cruising in a straight-line when restraining diver movement is simulated, and five cases with free diver movement are simulated too.  ...  Diver propulsion vehicles (hereinafter referred to as DPV) are a kind of small vehicle with underwater high-speed used by divers, who are able to grasp or ride on, and operate the volume switch to change  ...  The problem of divers driving DPV in the water is essentially the mutual disturbance of multiple underwater objects, such as the problem of the submarine running near the wall, the problem of two vehicles  ... 
doi:10.3390/jmse9020140 fatcat:od2c6i5bhbcfxewik5bgc4d4oe

Dynamical 3-Space: A Review [article]

Reginald T Cahill
2007 arXiv   pre-print
, leading to a derivation and explanation of gravity as a refraction effect of quantum matter waves.  ...  field describing the relative internal motion of the structured 3-space.  ...  Thomas and Vogel [34] performed another bore hole experiment at the Nevada Test Site in 1989 in which they measured the gravity gradient as a function of depth, the local average matter density, and the  ... 
arXiv:0705.4146v2 fatcat:j4gwy3vqxfegrn65dxcymy6q64

Geodesist's Handbook 2008

Hermann Drewes
2008 Journal of Geodesy  
At all times the group is open for new contacts and members in order to embed the activities in a wide context.  ...  The research activities shall be coordinated between the participating scientists and shall be conducted in interdisciplinary collaboration.  ...  However, local gravity field modelling still requires additional high-resolution information such as from terrestrial gravity observations or local topography data.  ... 
doi:10.1007/s00190-008-0259-0 fatcat:2wefhbpbl5a5rduy5prl54k67m
« Previous Showing results 1 — 15 out of 423 results