2-D gravity modeling with analytically defined geometry and quadratic polynomial density functions

Geophysics ◽  
1999 ◽  
Vol 64 (6) ◽  
pp. 1730-1734 ◽  
Author(s):  
Beatriz Martín‐Atienza ◽  
Juan García‐Abdeslem
Keyword(s):  
Numerical Methods ◽  
Polynomial Function ◽  
Continuous Functions ◽  
Model Solution ◽  
Gravity Modeling ◽  
Density Functions ◽  
Gravity Effect ◽  
New Methods ◽  
Order Polynomial ◽  
Broad Variety

New methods for 2-D modeling of gravity anomaly data are developed following an approach that uses both analytic and numerical methods of integration. The forward‐model solution developed here is suitable to calculate the gravity effect caused by a 2-D source body bounded either laterally or vertically by continuous functions. In our models, the density contrast is defined by a second‐order polynomial function of depth and distance along the profile. We present several examples to show that our models are capable of accommodating a broad variety of geologic structures.

A method to compute terrain corrections for gravimeter stations using a digital elevation model

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1110-1115 ◽  
Author(s):  
J. Garca‐Abdeslem ◽  
B. Martn‐Atienza
Keyword(s):  
Numerical Methods ◽  
Digital Elevation Model ◽  
Mass Density ◽  
Model Solution ◽  
Gravitational Attraction ◽  
Gravity Effect ◽  
Gravity Station ◽  
Digital Elevation ◽  
Terrain Corrections ◽  
Elevation Model

A description is given of a method to compute the terrain corrections for a gravity survey using a digital elevation model. This method is based upon a new forward model solution to compute the gravity effect due to a rectangular prism of uniform mass density that is flat at its base but has a nonflat top. The gravitational attraction of such a prism is evaluated at the gravity station locations by combining analytic and numerical methods of integration. Two simple synthetic examples are provided that show the accuracy of this numerical method, and its performance is illustrated in a field example.

Polynomial Moving Fitting Method for Edge Identification

2011 ◽  
Vol 308-310 ◽  
pp. 2560-2564 ◽  
Author(s):  
Xiang Rong Yuan
Keyword(s):  
Edge Detection ◽  
Curve Fitting ◽  
Polynomial Function ◽  
High Order ◽  
Polynomial Fitting ◽  
Fitting Method ◽  
Order Polynomial ◽  
Better Than ◽  
Low Order

A moving fitting method for edge detection is proposed in this work. Polynomial function is used for the curve fitting of the column of pixels near the edge. Proposed method is compared with polynomial fitting method without sub-segment. The comparison shows that even with low order polynomial, the effects of moving fitting are significantly better than that with high order polynomial fitting without sub-segment.

First-passage-time densities for time-non-homogeneous diffusion processes

1997 ◽  
Vol 34 (3) ◽  
pp. 623-631 ◽  
Author(s):  
R. Gutiérrez ◽  
L. M. Ricciardi ◽  
P. Román ◽  
F. Torres
Keyword(s):  
Diffusion Processes ◽  
First Passage Time ◽  
Passage Time ◽  
Continuous Functions ◽  
Probability Density Functions ◽  
Density Functions ◽  
First Passage ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Natural Boundaries

In this paper we study a Volterra integral equation of the second kind, including two arbitrary continuous functions, in order to determine first-passage-time probability density functions through time-dependent boundaries for time-non-homogeneous one-dimensional diffusion processes with natural boundaries. These results generalize those which were obtained for time-homogeneous diffusion processes by Giorno et al. [3], and for some particular classes of time-non-homogeneous diffusion processes by Gutiérrez et al. [4], [5].

Visual-Haptic Relations in a Two-Dimensional Size-Matching Task

1994 ◽  
Vol 78 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Laura M. Schultz ◽  
J. Timothy Petersik
Keyword(s):  
Factorial Design ◽  
Repeated Measures ◽  
Task Analysis ◽  
Polynomial Function ◽  
Size Perception ◽  
Matching Task ◽  
Two Dimensional ◽  
Matching Accuracy ◽  
Third Order ◽  
Order Polynomial

Visual and haptic perceptions of the two-dimensional size of square stimuli were compared using cross-modal, intramodal, and bimodal matching tasks. In a repeated-measures factorial design, 12 women participated in five matching tasks involving various combinations of vision and haptic touch; five sizes of standard squares were matched with a comparison range of 10 squares during each task. Analysis showed that, for stimuli with side lengths of .75 in. and smaller, matching accuracy was superior when vision was used during the matching task regardless of the modality used during inspection. When haptic touch was used in the matching task, accuracy was better when vision had been used during inspection than when it bad not. These results were consistent with those of previous studies comparing size perception by vision and other forms of touch. The over-all relationship between matched size and inspected size was best accounted for by a third-order polynomial function.

A Novel Constitutive Model for Concrete under Uniaxial Compression

2010 ◽  
Vol 650 ◽  
pp. 47-55 ◽  
Author(s):  
Jin Long Pan ◽  
Jia Jia Zhou ◽  
Zong Jin Li ◽  
Christopher K.Y. Leung
Keyword(s):  
Constitutive Model ◽  
Uniaxial Compression ◽  
Poisson’S Ratio ◽  
Longitudinal Strain ◽  
Polynomial Function ◽  
Poisson's Ratio ◽  
Test Results ◽  
Proposed Model ◽  
Order Polynomial

In this paper, a novel constitutive model of concrete has been proposed by introducing a new parameter, namely, cracking Poisson’s ratio (νcr), to account for the effect of localization due to cracking. By fitting the curve between the dimensionless strain (ε/εpr) and cracking Poisson’s ratio (νcr), νcr can be expressed as an 3rd order polynomial function of dimensionless longitudinal strain (ε/εpr). The constitutive model for the softening regime can then be proposed with the parameters of dimensionless strain and cracking Poisson’s ratio. Finally, Validity of the proposed model is verified by the test results of cylinder specimens of C30.

scholarly journals Predicting the Frequency Characteristics of Hybrid Meander Systems Using a Feed-Forward Backpropagation Network

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 85 ◽  
Author(s):  
Darius Plonis ◽  
Andrius Katkevičius ◽  
Audrius Krukonis ◽  
Vaiva Šlegerytė ◽  
Rytis Maskeliūnas ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Design Process ◽  
Method Of Moments ◽  
Experimental Results ◽  
Reflection Factor ◽  
Transmission Factor ◽  
Feed Forward ◽  
New Methods ◽  
Backpropagation Network ◽  
Hidden Layer

The process of designing microwave devices is difficult and time-consuming because the analytical and numerical methods used in the design process are complex. Therefore, it is necessary to search for new methods that will allow for an acceleration of synthesis and analytic procedures. This is especially important in cases where the procedures of synthesis and analysis have to be repeated many times, until the correct device configuration is found. Artificial neural networks are one of the possible alternatives for the acceleration of the design process. In this paper we present a procedure for analyzing a hybrid meander system (HMS) using the feed-forward backpropagation network (FFBN). We compared the prediction results of the transmission factor and the reflection factor , obtained using the FFBN, with results obtained using traditional analytical and numerical methods, as well as with experimental results. The comparisons show that prediction results significantly depend on the FFBN structure. In terms of the lowest difference between the characteristics calculated using the method of moments (MoM) and characteristics predicted using the FFBN, the best prediction was achieved using the FFBN with three hidden layers, which included 18 neurons in the first hidden layer, 14 neurons in the second hidden layer, and 2 neurons in the third hidden layer. Differences between the predicted and calculated results did not exceed 7% for the parameter and 5% for the parameter. The prediction of parameters using the FFBN allowed the analysis procedure to be sped up from hours to minutes. The experimental results correlated with the predicted characteristics.

SOME RESULTS ON COMPARING TWO INTEGRAL MEANS FOR ABSOLUTELY CONTINUOUS FUNCTIONS AND APPLICATIONS

2014 ◽  
Vol 90 (2) ◽  
pp. 264-274
Author(s):  
DAH-YAN HWANG ◽  
SILVESTRU SEVER DRAGOMIR
Keyword(s):  
Probability Density ◽  
Continuous Functions ◽  
Probability Density Functions ◽  
Density Functions ◽  
Absolutely Continuous Functions ◽  
Integral Means ◽  
Absolutely Continuous ◽  
Special Means ◽  
The Difference

AbstractSome better estimates for the difference between the integral mean of a function and its mean over a subinterval are established. Various applications for special means and probability density functions are also given.

Footfall Deflection of Antifatigue Flooring During Simulated Human Stance

2020 ◽  
pp. 106480462097573
Author(s):  
Jackie D. Zehr ◽  
Taylor B. Winberg ◽  
Andrew C. Laing ◽  
Jack P. Callaghan
Keyword(s):  
Polynomial Function ◽  
Vertical Deflection ◽  
Shore Hardness ◽  
Third Order ◽  
Compression Load ◽  
Single Leg Stance ◽  
Order Polynomial ◽  
Standardized Measurement ◽  
The Relationship

This study quantified the effect of compression load and duration on the deflection of five separate antifatigue flooring surfaces. Following standardized measurement of A Shore hardness, each sample underwent simulated single-leg stance indentation procedures that differed by compression load (45.3 kg, 90.7 kg, 136.1 kg) and duration (initial = 2.5 s, intermediate = 6.25 s, final = 12.5 s). Vertical deflection was compared across conditions, and the relationship between A Shore hardness and deflection was characterized. When compressed with 45.3 kg, deflection was not influenced by duration, but at 136 kg, deflection differed between durations by up to 15%. The relationship between A Shore hardness and deflection was characterized by a third-order polynomial function ( R2 > 0.991).

Overview of a Few Key Issues for Optimal Operation of Parallel Pumping Stations

2012 ◽  
Vol 212-213 ◽  
pp. 1217-1222
Author(s):  
Yi Gong ◽  
Gang Shen ◽  
Kui Zuo ◽  
Han Sheng Shi
Keyword(s):  
Large Scale ◽  
Solution Process ◽  
Optimization Methods ◽  
Optimal Operation ◽  
Model Solution ◽  
New Methods ◽  
Pump Station ◽  
Operational Optimization ◽  
Pumping Stations ◽  
Key Issues

For the operational optimization issues of the parallel pumping stations, on the two aspects, the multi-pump station and the parallel pumping stations, the solutions to the constructed models are illustrated, and a few key issues of the model solution process are described. Therefore, while providing a few new methods to construct and to solve the models, the optimization methods of large scale system is enriched and developed.

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