Super-resolution fusion of complementary panoramic images based on cross-selection kernel regression interpolation

In the Dauphinoise zone of the French Western Alps, a posttectonic thermoremanent magnetization, carried by pyrrhotite, has been isolated. The paleomagnetic signature is interpreted as the record of successive partial thermoremanent magnetizations of opposite directions acquired during the early Miocene slow cooling of the epimetamorphic marly limestones of the studied area. A local vertical thermal gradient of 22 ± 2 °C/km was derived from the unblocking temperature of a reversal recorded at different altitudes. Using this vertical gradient, we have produced a paleotemperature map at the time of the reversal (about 20 Ma). The map shows a horizontal regional thermal gradient of 7 °C/km; the higher temperatures were toward the crystalline basement. Paleomagnetic directions demonstrate that this horizontal gradient was present during cooling. Its origin can be explained by large-volume fluid circulation along the major fault that forms the boundary between the crystalline basement and its Liassic cover.

The truncated plate and geologic contact are commercially important structures which can be located by the gravity method. The interpretation can be improved if both the horizontal and vertical gradients are known. Vertical gradients are difficult to measure precisely, but with modern gravimeters the horizontal gradient can be measured conveniently and accurately. This paper shows how the vertical gradient can be obtained from the horizontal gradient by the use of a Hilbert transform. A procedure is then presented which easily enables the position, dip angle, depth, thickness, and density contrast of a postulated plate to be precisely and unambiguously derived from a plot of the horizontal gradient against the vertical gradient at each point measured. The procedure is demonstrated using theoretical data.

In this study, we designed an autonomous mobile robot based on the rules of the Federation of International Robotsoccer Association (FIRA) RoboSot category, integrating the techniques of computer vision, real-time image processing, dynamic target tracking, wireless communication, self-localization, motion control, path planning, and control strategy to achieve the contest goal. The self-localization scheme of the mobile robot is based on the algorithms featured in the images from its omni-directional vision system. In previous works, we used the image colors of the field goals as reference points, combining either dual-circle or trilateration positioning of the reference points to achieve selflocalization of the autonomous mobile robot. However, because the image of the game field is easily affected by ambient light, positioning systems exclusively based on color model algorithms cause errors. To reduce environmental effects and achieve the self-localization of the robot, the proposed algorithm is applied in assessing the corners of field lines by using an omni-directional vision system. Particularly in the mid-size league of the RobotCup soccer competition, selflocalization algorithms based on extracting white lines from the soccer field have become increasingly popular. Moreover, white lines are less influenced by light than are the color model of the goals. Therefore, we propose an algorithm that transforms the omni-directional image into an unwrapped transformed image, enhancing the extraction features. The process is described as follows: First, radical scan-lines were used to process omni-directional images, reducing the computational load and improving system efficiency. The lines were radically arranged around the center of the omni-directional camera image, resulting in a shorter computational time compared with the traditional Cartesian coordinate system. However, the omni-directional image is a distorted image, which makes it difficult to recognize the position of the robot. Therefore, image transformation was required to implement self-localization. Second, we used an approach to transform the omni-directional images into panoramic images. Hence, the distortion of the white line can be fixed through the transformation. The interest points that form the corners of the landmark were then located using the features from accelerated segment test (FAST) algorithm. In this algorithm, a circle of sixteen pixels surrounding the corner candidate is considered and is a high-speed feature detector in real-time frame rate applications. Finally, the dual-circle, trilateration, and cross-ratio projection algorithms were implemented in choosing the corners obtained from the FAST algorithm and localizing the position of the robot. The results demonstrate that the proposed algorithm is accurate, exhibiting a 2-cm position error in the soccer field measuring 600 cm2 x 400 cm2.

The relative bending effects on a radio ray of the horizontal and vertical gradient of refractivity are investigated. With the use of ray-curvature formulas developed by Wong, convenient differential equations governing the three-dimensional ray path are derived. It is also shown that the ratio of ‘horizontal to vertical’ bending effects is maximum when the ray is propagated in the vertical plane containing the horizontal gradient of refractivity. In a two-dimensional example, computations of path height as a function of horizontal distance are obtained by numerical integration, For this purpose, a regional space-time averaged exponential model drawn from climatologieal studies of Bean and Thayer has been used. Even though this smoothed model and an extreme version of it derived synthetically by increasing the horizontal gradient everywhere by a factor of 10 have comparatively strong horizontal gradients, the ‘horizontal bending’ effect is virtually negligible. It is not implied, however, that this conclusion is necessarily applicable to an atmosphere exhibiting small-scale fluctuations in the refractivity pattern. The ray paths corresponding to the nonhomogeneous model are significantly different from those in a horizontally uniform atmosphere. The problem of replacing a nonhomogeneous model by an equivalent horizontally uniform one is also investigated. The choice of the best uniform atmosphere depends upon minimizing the rms height error over a designated horizontal path length, and this in turn requires the specification of several ray-propagation parameters in addition to the distribution of refractivity.

Investigating horizontal and vertical pollution gradients in the atmosphere associated with an urban location in complex terrain, Reno, Nevada, USA

Pumped groundwater sampling evaluations often assume that horizontal head gradients predominate and the sample comprises an average of water quality variation over the well screen interval weighted towards contributing zones of higher hydraulic conductivity (a permeability-weighted sample). However, the pumping rate used during sampling may not always be sufficient to overcome vertical flows in wells driven by ambient vertical head gradients. Such flows are reported in wells with screens between 3 and 10m in length where lower pumping rates are more likely to be used during sampling. Here, numerical flow and particle transport modeling is used to provide insight into the origin of samples under ambient vertical head gradients and under a range of pumping rates. When vertical gradients are present, sample provenance is sensitive to pump intake position, pumping rate and pumping duration. The sample may not be drawn from the whole screen interval even with extended pumping times. Sample bias is present even when the ambient vertical flow in the wellbore is less than the pumping rate. Knowledge of the maximum ambient vertical flow in the well does, however, allow estimation of the pumping rate that will yield a permeability-weighted sample. This rate may be much greater than that recommended for low-flow sampling. In practice at monitored sites, the sampling bias introduced by ambient vertical flows in wells may often be unrecognized or underestimated when drawing conclusions from sampling results. It follows that care should be taken in the interpretation of sampling data if supporting flow investigations have not been undertaken.

The ecophysiological parameters of coffee canopy were mapped throughout the day. Therefore, evaluations were carried out in ‘Catuaí Vermelho’<em> Coffea arabica</em> L., measuring 1.7 meters. A vertical gradient (from the apex to the base of the plant canopy) and a horizontal gradient (plagiotropic branches) were established to analyze different positions of the canopy. Thus, in the vertical direction, four heights were analyzed in the plant: top, upper, middle and lower regions. In the horizontal gradient, the plagiotropic branches were divided into three parts: basal, median and apical. Collection was performed on the east and west sides of the canopy, at four times of the day: 6 a.m., 9 a.m., noon, and 3 p.m., totaling 24 collection points at each time. Gas exchange, photosynthetically active radiation and leaf temperature were evaluated in each of the 24 points of the coffee canopy. The gas exchange characteristics of an individual coffee leaf diverge considerably from other leaves, which require caution when scaling estimates of leaf photosynthesis at the global canopy level. The analysis of some punctual leaves does not serve to discriminate the overall dynamics of a canopy.

The spatial variability of the total chlorophyll content and carotenoids content, starch and soluble sugars of coffee canopy were mapped throughout the day. Therefore, evaluations were carried out in a ‘Catuaí Vermelho’ coffee plant with 1.7 meters height. A vertical gradient (from the apex to the base of the plant canopy) and a horizontal gradient (plagiotropic branches) were established to analyze different positions of the canopy. Thus, in the vertical direction, four heights were analyzed in the plant: top, upper, middle and lower regions. In the horizontal gradient, the plagiotropic branches were divided into three parts: basal, median and apical. Collection of leaf samples was performed on the east and west sides of the canopy, at 9 a.m., totaling 24 collection points at each time. Higher content of photosynthetic pigments and concentration of sugars were observed in the western face and in the inner parts of the coffee tree. The content of chloroplast pigments and sugars of an individual coffee leaf diverge considerably from other leaves, which requires caution when scaling estimates at the global canopy level. The analysis of some punctual leaves does not serve to discriminate the overall dynamics of a canopy.

According to the water temperature of Jiaozhou Bay in May, August and October of 1979, based on its horizontal and vertical variation, and the difference between water temperature at surface and bottom, the impact of the transport amount and time of water temperature heat on its variation at surface and bottom and regional variation was studied. The results showed that in May, from northeastern to northern nearshore waters, water temperature reached high as 15.30-16.50 °C, which began to rise from inside waters to bay mouth, and to outside waters. In August, from eastern to northern nearshore waters, it reached high as 28.09-28.70 °C, which began to rise in same order. In October, in eastern nearshore waters, it was as high as 18.39°C, which began to increase from outside waters to bay mouth, and to inside waters. Regionally, from inside waters to bay mouth and outside waters, the minus of water temperature at surface and bottom showed that when it was transported to Jiaozhou Bay, it first reached the surface, then rapidly and constantly to sea floor, showing the variation of water temperature at surface and bottom. Spatially, water temperature at surface caused low heat and slow increase along with the horizontal and vertical gradients in May, high heat and rapid increase in August and heat and increase in October. Besides, the homogeneous layer was formed in outside waters vertically from surface and bottom. In bay mouth, water temperature at bottom was slightly higher than that at surface, whereas, in inside waters, it was opposite. Therefore, the temporal and spatial variation displayed the variation of water temperature at surface along with horizontal and vertical gradients. In addition, the modelling diagram was proposed and the transport direction and variation process of water temperature heat at surface were clarified.

Summary Purpose. The work of a GIS shell with a web interface is analyzed aimed to support oil-and-gas reservoirs during its development by processing the data from gravity variations monitoring. The shell is implemented based on Post¬GIS and tested on the example of processing monitoring data for one oil and gas reservoir. Method. Data processing involves a number of procedures, such as data averaging along the measurement profile by the moving average technique with the calculation of residual local anomalies, the analytical approximation of the gravity curve by a trend, the calculation of the residual field and differentiation (i.e. calculation of its horizontal and vertical gradients). Data modeling means the solution of direct gravimetry problems by the fitting. To optimize the model, mathematical models of the medium were calculated using the simulated annealing technique. Results. The GIS shell GravGIS has been developed to solve applied problems of processing monitoring data for oil-and-gas reservoirs of Kazakhstan. It provides for the calculation of gravity transformants such as first and second derivatives, horizontal and vertical gradients, mathematical norms, etc. For modeling the oil-and-gas reservoir in this shell, GeoM computing unit is introduced for solution of direct problems of gravimetry. A 1-D solution to the problem by the method of simple iteration was developed. Solutions of direct problems of gravimetry by the simulated annea¬ling technique are tested for gravitating objects specified by elementary approximating bodies (sphere, ledge, hori¬zontal and vertical prism, etc.) and are consistent with solutions of these problems by other methods. Practical value. The system allows combining data from monitoring gravity and other geophysical methods. Inte¬gration of these data and gravity inversion with the constraints of a priori parameters of the geological media allows making optimal decisions.

The coarse sand barrier is considered as a promising measure to prevent backward erosion piping from causing failure of embankments. A pipe is allowed to progress backwards until it encounters the coarse sand barrier, which prevents it from progressing unless the head difference over the embankment is significantly increased. A three stage experimental programme supported by groundwater flow modelling is carried out to investigate the feasibility of this method. The hypothesis is that the strength of the barrier is characterised by a local gradient at the interface between the barrier and the pipe. Major questions are: can the horizontal gradient as measured in laboratory tests be used to characterise the strength of the barrier material, over which distance should a horizontal gradient be determined, and is this distance the same for models at different scales? This paper presents the background theory and demonstrates the effects using scale dependent criteria. Preliminary results of small- and medium-scale experiments are used to compare the two approaches.

An analysis is presented to describe the effects of Darcy resistance, fluid inertia, and horizontal density gradient on a heterogeneous Boussinesq fluid saturated porous medium in the presence of the vertical gravitational field using the Forchheimer-Lapwood extended Darcy (DLF) equation. The fluid is initially at rest, and sets in motion owing to two forms of the initial density gradients. One is the constant initial horizontal density gradient and the other is the piecewise constant density gradient. In the case of the uniform initial horizontal density gradient a purely horizontal motion develops satisfying the nonlinear Forchheimer extended Darcy (FD) equation. Analytical solution of this equation is obtained and limiting solutions valid for the Darcy regime and for a nonviscous fluid in the absence of porous media are derived. A measure of the stability of the flow is discussed briefly using the Richardson number. A comparison between the nature of solutions satisfying the nonlinear and linear initial value problems is made. We found that the vertical density gradient varies continuously both with space z and time t but the horizontal density gradient remains unchanged. In the case of a piecewise constant initial density gradient with continuous distribution of density, stream function formulation is used and the solutions are obtained using time-series analysis. In this case the solution shows crowding of the density profiles in the lower half of the channel, reflecting an increase in density gradient and incipient frontogenesis there, because of the increase in circulation of the flow due to the piecewise initial density gradient. Copyright © 2001 by Begell House, Inc.

Neural networks for 3D temperature field reconstruction via acoustic signals

The MHD virial theorem may be used to estimate the magnetic energy of active regions on the basis of vector magnetic fields measured at the photosphere or chromosphere. However, the virial estimate depends on the measured vector magnetic field being force-free. Departure from the force-free condition leads to an unknown systematic error in the virial energy estimate and an origin dependence of the result. We present a method for estimating the systematic error by assuming that magnetic forces are confined to a thin layer near the photosphere. If vector magnetic field measurements are available at two levels in the low atmosphere (e.g., the photosphere and the chromosphere), the systematic error may be directly calculated using the observed horizontal and vertical field gradients, resulting in an energy estimate that is independent of the choice of origin. If (as is generally the case) measurements are available at only one level, the systematic error may be approximated using the observed horizontal field gradients together with a simple linear force-free model for the vertical field gradients. The resulting improved virial energy estimate is independent of the choice of origin but depends on the choice of the model for the vertical field gradients, i.e., the value of the linear force-free parameter α. This procedure is demonstrated for five vector magnetograms, including a chromospheric magnetogram.

This paper presents algorithms for diagnosing the severity and location of damage in a laboratory bridge model. We use signal processing and machine learning approaches to analyze the vibration responses collected both directly from the bridge model and indirectly from a vehicle passing over the model. Features are selected using principal component analysis (PCA), and a regression is performed using the kernel regression method. Various “damage” severities and positions are simulated on a laboratory bridge model by placing additional mass on the bridge. We perform two experiments; one to measure our ability to detect damage severity (i.e. size of the mass), and a second to measure our ability to detect damage location (i.e. position of the mass). In the first experiment, we vary the magnitude of the mass while keeping its location constant. In the second experiment, we vary the location of the mass while keeping its magnitude constant. In both cases, we use a portion of our data to train the algorithm, and another portion to test its validity. We report the accuracy of correctly quantifying the nature of the mass from the test data as a mean square error (MSE). state of the structure for an infinite number of mass locations and sizes within our training set. To build the regression, we apply principal component analysis to the acceleration signals, and train the kernel regression model by the collected data. This model determines the size and the location of the damage proxy using the MSE as the evaluation score. 2 EXPERIMENTAL SETUP AND PROTOCOL 2.1 Experimental setup (Cerda et al. 2013; Wang et al. 2013) A general view of the laboratory model used in this project is shown in Figure 1, and schematic of the setup is shown in Figure 2. The model consists of a vehicle that is pulled across the rails by a cable system. The vehicle starts on ‘Ramp 1’, accelerates up to a constant speed, crosses the middle section, the “bridge,” then decelerates on ‘Ramp 2.’ The vehicle has wired accelerometers so there is a cable rail above to ensure these wires do not interfere with its motion. The “bridge” is an aluminum plate, 2438 mm (8 feet) long, with two angle beams acting as girders and two rails to guide the vehicle. The vehicle model, as shown in Figure 3, has an independent suspension system. Both the vehicle and the bridge were instrumented with commercial accelerometers. On the vehicle, two sensors are on the sprung portion of the vehicle (‘front chassis sensor’ and ‘rear chassis sensor’), and two sensors are on the unsprung portion of the vehicle, rigidly attached to the wheels (‘front wheel sensor’ and ‘rear wheel sensor’), as shown in Figure 3. One sensor was placed underneath the bridge deck at midspan (‘bridge sensor’). Figure 1. The general view of the laboratory setup. The motors governing the movement of the vehicle and the data-acquisition systems are both controlled by National Instrument’s PXI system running LabView . By using a single system, we can spatially align the time series data from different runs using the vehicle’s position. More details about the experimental setup can be found in (Cerda et al. 2013). Figure 2. The illustration of the laboratory model. Figure 3. Details of the vehicle.