Scattering, symmetry, and bias analysis of source‐position estimates in Euler deconvolution and its practical implications

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1149-1156 ◽  
Author(s):  
J. B. C. Silva ◽  
V. C. F. Barbosa ◽  
W. E. Medeiros
Keyword(s):  
Vertical Position ◽  
Lower Sensitivity ◽  
Horizontal Position ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Bias Analysis ◽  
Data Noise ◽  
Data Window ◽  
Symmetry Properties ◽  
Window Position

Despite being widely used, Euler deconvolution has received little attention in its theoretical aspects. We obtain analytical estimators [Formula: see text] and [Formula: see text] for the horizontal [Formula: see text] and the vertical [Formula: see text] source positions, which are the parameters to be estimated when the structural index is assigned a tentative value. By analyzing the estimators’ properties, we show two things. (1) Scattering of the alternative solutions associated with different data window positions has two components: data noise and the use of a wrong tentative value for the structural index, (2) The differences [Formula: see text] and [Formula: see text], as a function of the data window position, exhibit antisymmetric and symmetric behaviors, respectively, about [Formula: see text] when the magnetization and the geomagnetic field inclinations are 90°, 0°, or 45°. For intermediate inclinations there is a moderate departure from the symmetry properties. This analysis shows that the criterion for determining the structural index as the tentative value producing the smallest solution scattering is theoretically sound but occasionally fails in practice because data noise also contributes to solution scattering. In addition, the lower sensitivity of the averages of estimates of the horizontal position (as compared with the vertical position) occurs because [Formula: see text] displays an antisymmetric behavior with respect to the true horizontal position while the estimates of the vertical position display a symmetric behavior with respect to the same point.

Stability analysis and improvement of structural index estimation in Euler deconvolution

Geophysics ◽  
1999 ◽  
Vol 64 (1) ◽  
pp. 48-60 ◽  
Author(s):  
Valéria C. F. Barbosa ◽  
João B. C. Silva ◽  
Walter E. Medeiros
Keyword(s):  
Stability Analysis ◽  
Vertical Position ◽  
Horizontal Position ◽  
Total Field ◽  
Source Position ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Data Window ◽  
Base Level ◽  
New Criterion

Euler deconvolution has been widely used in automatic aeromagnetic interpretations because it requires no prior knowledge of the source magnetization direction and assumes no particular interpretation model, provided the structural index defining the anomaly falloff rate related to the nature of the magnetic source, is determined in advance. Estimating the correct structural index and electing optimum criteria for selecting candidate solutions are two fundamental requirements for a successful application of this method. We present a new criterion for determining the structural index. This criterion is based on the correlation between the total‐field anomaly and the estimates of an unknown base level. These estimates are obtained for each position of a moving data window along the observed profile and for several tentative values for the structural index. The tentative value for the structural index producing the smallest correlation is the best estimate of the correct structural index. We also propose a new criterion to select the best solutions from a set of previously computed candidate solutions, each one associated with a particular position of the moving data window. A current criterion is to select only those candidates producing a standard deviation for the vertical position of the source smaller than a threshold value. We propose that in addition to this criterion, only those candidates producing the best fit to the known quantities (combinations of anomaly and its gradients) be selected. The proposed modifications to Euler deconvolution can be implemented easily in an automated algorithm for locating the source position. The above results are grounded on a theoretical uniqueness and stability analysis, also presented in this paper, for the joint estimation of the source position, the base level, and the structural index in Euler deconvolution. This analysis also reveals that the vertical position and the structural index of the source cannot be estimated simultaneously because they are linearly dependent; the horizontal position and the structural index, on the other hand, are linearly independent. For a known structural index, estimates of both horizontal and vertical positions are unique and stable regardless of the value of the structural index. If this value is not too small, estimates of the base level for the total field are stable as well. The proposed modifications to Euler deconvolution were tested both on synthetic and real magnetic data. In the case of synthetic data, the proposed criterion always detected the correct structural index and good estimates of the source position were obtained, suggesting the present theoretical analysis may lead to a substantial enhancement in practical applications of Euler deconvolution. In the case of practical data (vertical component anomaly over an iron deposit in the Kursk district, Russia), the estimated structural index (corresponding to a vertical prism) was in accordance with the known geology of the deposit, and the estimates of the depth and horizontal position of the source compared favorably with results reported in the literature.

Peripheral representation of antennal orientation by the scapal hair plate of the cockroach Periplaneta americana

2001 ◽  
Vol 204 (24) ◽  
pp. 4301-4309 ◽  
Author(s):  
J. Okada ◽  
Y. Toh
Keyword(s):  
Single Unit ◽  
Periplaneta Americana ◽  
Vertical Component ◽  
Horizontal Component ◽  
Vertical Position ◽  
Horizontal Position ◽  
Joint Movement ◽  
Basal Segment ◽  
Dynamic Phase ◽  
Hair Sensilla

SUMMARY Arthropods have hair plates that are clusters of mechanosensitive hairs, usually positioned close to joints, which function as proprioceptors for joint movement. We investigated how angular movements of the antenna of the cockroach (Periplaneta americana) are coded by antennal hair plates. A particular hair plate on the basal segment of the antenna, the scapal hair plate, can be divided into three subgroups: dorsal, lateral and medial. The dorsal group is adapted to encode the vertical component of antennal direction, while the lateral and medial groups are specialized for encoding the horizontal component. Of the three subgroups of hair sensilla, those of the lateral scapal hair plate may provide the most reliable information about the horizontal position of the antenna, irrespective of its vertical position. Extracellular recordings from representative sensilla of each scapal hair plate subgroup revealed the form of the single-unit impulses in response to hair deflection. The mechanoreceptors were characterized as typically phasic-tonic. The tonic discharge was sustained indefinitely (>20 min) as long as the hair was kept deflected. The spike frequency in the transient (dynamic) phase was both velocity- and displacement-dependent, while that in the sustained (steady) phase was displacement-dependent.

3. On the Figures of Equilibrium of Liquid Films

1869 ◽  
Vol 6 ◽  
pp. 76-78
Author(s):  
David Brewster
Keyword(s):  
Soap Solution ◽  
Liquid Films ◽  
Vertical Position ◽  
Soap Bubble ◽  
Horizontal Position ◽  
Soap Films ◽  
Figures Of Equilibrium ◽  
New Phenomena

In repeating some of the experiments of Professor Plateau, described in seven interesting memoirs published in “The Transactions of the Belgian Academy,” and in prosecuting his own experiments on the colours of the soap-bubble, the author of this paper observed several new phenomena which may have escaped the notice of the Belgian philosopher.Professor Plateau has described and drawn the beautiful systems of soap-films, obtained by lifting from a soap solution a cube made of wires about one and a half inch long. This system is a polyhedron, composed of twelve similar films stretching from the wires, and united to a plane quadrangular film in the centre. When this vertical film was blown upon, M. Von Rees observed that it was reduced to a line, and then reproduced in a horizontal position, from which it could be blown again into a vertical position.

scholarly journals Three-dimensional interpretation of magnetic and gravity anomalies using the finite-difference similarity transform

Geophysics ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. L79-L90 ◽  
Author(s):  
Daniela Gerovska ◽  
Marcos J. Araúzo-Bravo ◽  
Kathryn Whaler ◽  
Petar Stavrev ◽  
Alan Reid
Keyword(s):  
Finite Difference ◽  
Random Noise ◽  
Source Parameters ◽  
Magnetization Vector ◽  
Real Data ◽  
Index Formula ◽  
Magnetic Data ◽  
Horizontal Position ◽  
Structural Index ◽  
Similarity Transform

We present an automatic procedure for interpretation of magnetic or gravity gridded anomalies based on the finite-difference similarity transform (FDST). It is called MaGSoundFDST (magnetic and gravity sounding based on the finite-difference similarity transform) and uses a “focusing” principle in contrast to deriving multiple clusters of many solutions as in the widely used Euler deconvolution method. The source parameters are characterized by isolated solutions, and the interpreter obtains parallel images showing the horizontal position, depth, and structural index [Formula: see text] value. The underlying principle is that the FDST of a potential field anomaly becomes zero or linear at all observation points when the central point of similarity (CPS) of the transform coincides with a source field’s singular point and a correct [Formula: see text] value is used. The procedure involves calculating a 3D function that evaluates the linearity of the FDST for a series of [Formula: see text] values, using a moving window and sounding the subsurface along a verticalline under each window center. We then combine the 3D results for different [Formula: see text] values into a single map whose minima determine the horizontal position of the sources. The [Formula: see text] value and the CPS depth associated with each minimum determine the [Formula: see text] value and depth of the corresponding source. Only one estimate characterizes a simple source, which is a major advantage over other window-based procedures. MaGSoundFDST uses only the measured anomalous field and its upward continuation, thus avoiding the direct use of field derivatives. It is independent of the magnetization-vector direction in the magnetic data case. The procedure accounts for a linear background of local gravity or magnetic anomalies and has been applied effectively to several cases of synthetic and real data. MaGSoundFDST shares common features with the magnetic and gravity sounding based on the differential similarity transform (MaGSoundDST) but is more stable in estimating depth and structural index in the presence of random noise.

Estimating the nature and the horizontal and vertical positions of 3D magnetic sources using Euler deconvolution

Geophysics ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. J87-J98 ◽  
Author(s):  
Felipe F. Melo ◽  
Valeria C. F. Barbosa ◽  
Leonardo Uieda ◽  
Vanderlei C. Oliveira Jr. ◽  
João B. C. Silva
Keyword(s):  
Synthetic Data ◽  
Real Data ◽  
Angular Coefficient ◽  
Coefficient Estimates ◽  
Euler Deconvolution ◽  
Structural Index ◽  
Vertical Coordinate ◽  
Base Level ◽  
The One ◽  
Inclined Planes

We have developed a new method that drastically reduces the number of the source location estimates in Euler deconvolution to only one per anomaly. Our method employs the analytical estimators of the base level and of the horizontal and vertical source positions in Euler deconvolution as a function of the [Formula: see text]- and [Formula: see text]-coordinates of the observations. By assuming any tentative structural index (defining the geometry of the sources), our method automatically locates plateaus, on the maps of the horizontal coordinate estimates, indicating consistent estimates that are very close to the true corresponding coordinates. These plateaus are located in the neighborhood of the highest values of the anomaly and show a contrasting behavior with those estimates that form inclined planes at the anomaly borders. The plateaus are automatically located on the maps of the horizontal coordinate estimates by fitting a first-degree polynomial to these estimates in a moving-window scheme spanning all estimates. The positions where the angular coefficient estimates are closest to zero identify the plateaus of the horizontal coordinate estimates. The sample means of these horizontal coordinate estimates are the best horizontal location estimates. After mapping each plateau, our method takes as the best structural index the one that yields the minimum correlation between the total-field anomaly and the estimated base level over each plateau. By using the estimated structural index for each plateau, our approach extracts the vertical coordinate estimates over the corresponding plateau. The sample means of these estimates are the best depth location estimates in our method. When applied to synthetic data, our method yielded good results if the bodies produce weak- and mid-interfering anomalies. A test on real data over intrusions in the Goiás Alkaline Province, Brazil, retrieved sphere-like sources suggesting 3D bodies.

On a New Type of Vibrating Lift

1980 ◽  
Vol 102 (2) ◽  
pp. 264-269
Author(s):  
J. Inoue ◽  
Y. Araki ◽  
S. Kubo
Keyword(s):  
The Self ◽  
The Other ◽  
Vertical Position ◽  
Horizontal Position ◽  
Linear Vibration ◽  
Left Hand ◽  
Asynchronous Motors ◽  
Rotational Vibration ◽  
New Type ◽  
The Right

This paper investigates in detail the new vibrating lift made by utilizing the principle of the self-synchronization of mechanical vibrators. In a general way products ride up inclined way of the spiral trough of a vibrating lift, propelled by forces generated by two unbalanced rotors connected by the gear and driven by a motor, which are mounted on top of the structure in a horizontal position. This machine is a new type of vibrating lift. The axes of two unbalanced rotors are nonparallel and each driven by two asynchronous motors. One motor is positioned on the right hand side and the other is situated on the left hand side of the structure in a vertical position. In spite of the absence of any connection between two rotors, they rotate at the same speed and have the definite phase angle between them as the result of the phenomena of the self-synchronization under a certain condition. This phenomenon is also called entrainment. Accordingly, by the linear vibration in the direction of the axis of the structure and rotational vibration about the axis of the structure by two unbalanced rotors, products ride up inclined way of the spiral trough.

scholarly journals Karakterisasi Prototipe Heater Element System pada Untai Uji RCCS-RDNK menggunakan Kamera Infra Merah

2020 ◽  
Vol 8 (2) ◽  
pp. 313
Author(s):  
DEDY HARYANTO ◽  
GIARNO GIARNO ◽  
JOKO PRASETIO WITOKO ◽  
GREGORIUS BAMBANG HERU KUSNUGROHO ◽  
RAHAYU KUSUMASTUTI ◽  
...  
Keyword(s):  
Cooling System ◽  
Infrared Camera ◽  
Electric Heating ◽  
Heating System ◽  
Vertical Position ◽  
Horizontal Position ◽  
Heater Element ◽  
Element System ◽  
Observation Method ◽  
Cavity Cooling

ABSTRAKReactor Cavity Cooling System (RCCS) adalah salah satu sistem keselamatan pada Reaktor Daya Non Komersial (RDNK). Untuk mensimulasikan keadaaan tersebut, dibuat prototype Heater Element System (HES) yang merupakan sistem pemanas listrik dan berfungsi untuk memberikan kalor pada simulator dinding RPV (wall) seperti pada acuan RPV tipe HTGR. Tujuan penelitian adalah untuk memperoleh karakteristik temperatur selama pemanasan prototype HES hingga mencapai temperature 400°C berdasarkan posisi vertikal dan horizontal HES. Metode pengamatan dilakukan dengan menggunakan kamera infra merah NEC tipe TH9100ML sebagai alat ukur temperatur dan alat visualisasi ditribusi temperatur. Hasil pengamatan menunjukkan, bahwa kehilangan kalor pada prototipe HES pada posisi vertikal lebih kecil dibandingankan pada posisi horizontal hal ini disebabkan karena luas permukaan pada posisi horizontal sebesar 7,260 cm2 lebih memungkinkan untuk kehilangan kalor lebih besar. Posisi vertikal temperatur yang dicapai pada wall prototipe HES lebih tinggi dibandingkan pada posisi horizontal.Kata Kunci: RCCS, Heater Element System, kamera infra merah, temperatur ABSTRACTReactor Cavity Cooling System (RCCS) is one of the safety systems in Non-Commercial Power Reactors (RDNK). To simulate this situation, a prototype Heater Element System (HES) was made using electric heating system as a heat sources and it serves to provide radiation heat to the RPV wall simulator as the reference of the RPV of HTGR type. The purpose of this study was to obtain the temperature characteristics during the heating of the HES prototype to reach temperatures of 400°C base on HES position, horizontal and vertical positions. The observation method was carried out using a TH9100ML infrared camera NEC type as a temperature measurement and a temperature distribution base on visualization. The observations show that the heat loss in the HES prototype in the vertical position is smaller than in the horizontal position because this is because the surface area in the horizontal position 7.260 cm2 is more likely to lose more heat. The vertical position the temperature achieved on the HES prototype wall is higher than in the horizontal position.Keywords: RCCS, Heater Element System, infrared camera, temperature

Bloom

2015 ◽  
Vol 5 (2) ◽  
pp. 78-85
Author(s):  
Ken Goldberg ◽  
Sanjay Krishnan ◽  
Fernanda Viégas ◽  
Martin Wattenberg
Keyword(s):  
Real Time ◽  
Vertical Velocity ◽  
Rate Of Change ◽  
The Internet ◽  
Vertical Position ◽  
Second Derivative ◽  
Horizontal Position ◽  
Earth Art ◽  
Time Changes

In Bloom, an Internet-based earth-art-work, minute movements of the Hayward Fault in California are detected by a seismograph, transmitted continuously via the Internet, and processed to generate an evolving field of circular blooms. The size and position of each bloom is based on real-time changes in Earth’s motion, measured as a vertical velocity continuously updated from the seismometer. The horizontal position of blooms is based on time, and their vertical position is based on magnitude of the second derivative or rate of change. Large movements create large blooms; small jitters create tiny buds. This essay presents several stills from the Bloom project, and an essay on the work and its creator, Ken Goldberg.

Response of Missile Erector Towers to Sudden Stops or Impact Loads

1957 ◽  
Vol 61 (562) ◽  
pp. 694-696
Author(s):  
Hugh L. Cox
Keyword(s):  
Digital Computer ◽  
Sudden Stops ◽  
Vertical Position ◽  
Impact Loads ◽  
Horizontal Position ◽  
Sudden Stop ◽  
Electronic Digital Computer ◽  
Load Factors

The Cantilever-Type mechanism often used in large missile erectors is subjected to heavy stresses when raising a missile from the horizontal to the vertical position for launching. In the event it becomes necessary to return the missile to the horizontal position, severe stresses in the erector, and possibly the missile itself may be developed if the lowering mechanism causes the erector to stop suddenly just before it reaches the horizontal position. This note presents a simple matric formulation of the problem which enables one who has access to an electronic digital computer to compute maximum deflections and load factors that occur as a result of a sudden stop.

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