RESISTIVITY INVERSION

Geophysics ◽  
1973 ◽  
Vol 38 (6) ◽  
pp. 1088-1108 ◽  
Author(s):  
Joseph R. Inman ◽  
Jisoo Ryu ◽  
Stanley H. Ward
Keyword(s):  
Mean Value ◽  
Model Parameters ◽  
System Matrix ◽  
Resistive Layer ◽  
Free Data ◽  
Direct Interpretation ◽  
Data Points ◽  
Resistivity Inversion ◽  
High Degree ◽  
Generalized Inverse Method

The problem of direct interpretation of apparent resistivity curves from horizontally layered models is accomplished by using the generalized linear inverse theory. The method permits the resolution of the model parameters to be determined. The method also indicates which data points contain relatively important information necessary to resolve the model parameters. Two models were chosen to test the inversion scheme. One model has increasing resistivity with depth, and the other model possesses an intermediate resistive layer. Both models were resolved with a very high degree of accuracy from noise‐free data. When noise was added to the data, the values of the parameters oscillated about a mean value. The noise had little effect on the well‐resolved parameters but the poorly resolved parameters were in error by as much as 15 percent. The importance of each data point relative to the model was analyzed. The effect of certain data points on specific parameters was also determined. The generalized inverse method requires that the eigenvalues and eigenvectors of the system matrix be found. A comparison of the eigenvalues indicates those parameters that are well‐resolved and those that are poorly resolved from a given set of data.

scholarly journals Bark Characteristics of Scots Pine Logs

2020 ◽  
Vol 3 (1) ◽  
pp. 66
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
Waste Product ◽  
Mean Value ◽  
Bark Thickness ◽  
Water Displacement ◽  
Federal States ◽  
Bark Damage ◽  
Great Relevance ◽  
High Degree

The wood of Scots pine (Pinus sylvestris L.) shows good properties as building and construction timber but also as furniture or pulp and paper, and thus, is one of the most commercially important European tree species. Scots pine are mostly harvested and processed with a high degree of mechanization. In Northeast Germany (federal states of Brandenburg and Berlin), 36% of harvested Scots pine have a diameter at breast height (DBH) between 7 and 19.9 cm. As a typical industrial wood assortment, a large proportion of the resulting small-sized logs are used in the wood industry to produce boards. Although bark is considered a by-product or waste product of the industry, no actual study has quantified the bark thickness, bark volume, bark mass and bark damage of such Scots pine logs. Therefore, the bark characteristics from 50 logs from 10 different piles were analyzed. Bark volume was quantified using the water displacement method, bark mass by weighing, bark thickness with a precision caliper and bark damage by tape measurements. The diameters of the analyzed 150 log discs were normally distributed and the mean value was 12.9 cm. The results showed average bark damages from 12.0%, which were mostly caused during the felling and processing of logs with the harvester. No significant correlation was found between double bark thickness (mean: 3.0 mm) and the diameter; whereas fresh bark volume (mean: 5.6%) and dry bark mass (mean: 3.3%) were significantly affected by the diameter. As shown for spruce by other authors, bark characteristics may change over time and therefore, should be measured regularly. Moreover, it was shown that bark parameters are site dependent. Thus, quantifying bark characteristics for economically important tree species at both the local and national scale is of great relevance. More detailed analyzes are described by Berendt et al. (2021) [1].

Unsupervised labelling of remote sensing images based on force field clustering

2021 ◽  
pp. 1-14
Author(s):  
Zhenggang Wang ◽  
Jin Jin
Keyword(s):  
Remote Sensing ◽  
Force Field ◽  
Image Data ◽  
Model Parameters ◽  
Remote Sensing Images ◽  
Initial Cluster ◽  
Data Points ◽  
Global Optimal ◽  
Density Force

Remote sensing image segmentation provides technical support for decision making in many areas of environmental resource management. But, the quality of the remote sensing images obtained from different channels can vary considerably, and manually labeling a mass amount of image data is too expensive and Inefficiently. In this paper, we propose a point density force field clustering (PDFC) process. According to the spectral information from different ground objects, remote sensing superpixel points are divided into core and edge data points. The differences in the densities of core data points are used to form the local peak. The center of the initial cluster can be determined by the weighted density and position of the local peak. An iterative nebular clustering process is used to obtain the result, and a proposed new objective function is used to optimize the model parameters automatically to obtain the global optimal clustering solution. The proposed algorithm can cluster the area of different ground objects in remote sensing images automatically, and these categories are then labeled by humans simply.

Analysis of Vehicle Dynamic Performance Based on MATLAB

2013 ◽  
Vol 860-863 ◽  
pp. 1725-1728
Author(s):  
Fan Biao Bao
Keyword(s):  
Research Method ◽  
Dynamic Performance ◽  
Specific Model ◽  
Paper Analysis ◽  
Power Balance ◽  
Model Parameters ◽  
Vehicle Dynamic ◽  
Clear Physical Meaning ◽  
New Ideas ◽  
High Degree

This document focus on the car's dynamic performance characteristics.Because MATLAB has many advantages such as intuitive, clear physical meaning, a small amount of programming, data visualization and high degree of merit. This paper Computes and analysis with the introduction of an instance practice vehicle models.In light of the specific model parameters, this paper has analyzed car driver and driving resistance balance, power balance and power factor based on the application of Mat Lab's data analysis and graphics, and drawn the relevant graph, according to the mapping feature maps.The paper analysis of the car comprehensive power the car's dynamic graphing features calculation and research method are provided. The paper has provided new ideas of vehicle parameter selection and design.It has some practical value.

Respiration in the African Lungfish Protopterus Aethiopicus

1968 ◽  
Vol 49 (2) ◽  
pp. 437-452 ◽  
Author(s):  
CLAUDE LENFANT ◽  
KJELL JOHANSEN
Keyword(s):  
Gas Exchange ◽  
Haemoglobin Concentration ◽  
Temperature Shift ◽  
Mean Value ◽  
Gas Analysis ◽  
Air Exposure ◽  
Air Breathing ◽  
African Lungfish ◽  
High Degree ◽  
Protopterus Aethiopicus

1. Respiratory properties of blood and pattern of aerial and aquatic breathing and gas exchange have been studied in the African lungfish, Protopterus aethiopicus. 2. The mean value for haematocrit was 25%. Haemoglobin concentration was 6.2 g% and O2 capacity 6.8 vol. %. 3. The affinity of haemoglobin for O2 was high. P50 was 10 mm. Hg at PCOCO2, 6 mm. Hg and 25 °C. The Bohr effect was smaller than for the Australian lungfish, Neoceratodus, but exceeded that for the South American lungfish, Lepidosiren. The O2 affinity showed a larger temperature shift in Protopterus than Neoceratodus. 4. The CO2 combining power and the over-all buffering capacity of the blood exceeded values for the other lungfishes. 5. Both aerial and aquatic breathing showed a labile frequency. Air exposure elicited a marked increase in the rate of air breathing. 6. When resting in aerated water, air breathing accounted for about 90% of the O2 absorption. Aquatic gas exchange with gills and skin was 2.5 times more effective than pulmonary gas exchange in removing CO2. The low gas-exchange ratio for the lung diminished further in the interval between breaths. 7. Protopterus showed respiratory independence and a maintained O2 uptake until the ambient O2 and CO2 tensions were 85 and 35 mm. Hg respectively. A further reduction in O2 tension caused an abrupt fall in the oxygen uptake. 8. Gas analysis of blood samples drawn from unanaesthetized, free-swimming fishes attested to the important role of the lung in gas exchange and the high degree of functional separation in the circulation of oxygenated and deoxygenated blood.

Adaptive tensegrity locomotion: Controlling a compliant icosahedron with symmetry-reduced reinforcement learning

2019 ◽  
pp. 027836491985944 ◽  
Author(s):  
David Surovik ◽  
Kun Wang ◽  
Massimo Vespignani ◽  
Jonathan Bruce ◽  
Kostas E Bekris
Keyword(s):  
Reinforcement Learning ◽  
Policy Design ◽  
Model Parameters ◽  
Locomotion Control ◽  
Small Variety ◽  
Sample Data ◽  
Hybrid Framework ◽  
Varying Environments ◽  
High Degree ◽  
Flat Ground

Tensegrity robots, which are prototypical examples of hybrid soft–rigid robots, exhibit dynamical properties that provide ruggedness and adaptability. They also bring about, however, major challenges for locomotion control. Owing to high dimensionality and the complex evolution of contact states, data-driven approaches are appropriate for producing viable feedback policies for tensegrities. Guided policy search (GPS), a sample-efficient hybrid framework for optimization and reinforcement learning, has previously been applied to generate periodic, axis-constrained locomotion by an icosahedral tensegrity on flat ground. Varying environments and tasks, however, create a need for more adaptive and general locomotion control that actively utilizes an expanded space of robot states. This implies significantly higher needs in terms of sample data and setup effort. This work mitigates such requirements by proposing a new GPS -based reinforcement learning pipeline, which exploits the vehicle’s high degree of symmetry and appropriately learns contextual behaviors that are sustainable without periodicity. Newly achieved capabilities include axially unconstrained rolling, rough terrain traversal, and rough incline ascent. These tasks are evaluated for a small variety of key model parameters in simulation and tested on the NASA hardware prototype, SUPERball. Results confirm the utility of symmetry exploitation and the adaptability of the vehicle. They also shed light on numerous strengths and limitations of the GPS framework for policy design and transfer to real hybrid soft–rigid robots.

Effect of heat treatment on elastic properties of separated thermal barrier coatings

1999 ◽  
Vol 14 (12) ◽  
pp. 4643-4650 ◽  
Author(s):  
D. Basu ◽  
C. Funke ◽  
R. W. Steinbrech
Keyword(s):  
Elastic Moduli ◽  
Bulk Material ◽  
Mercury Porosimetry ◽  
Indentation Load ◽  
Elastic Response ◽  
Depth Sensing ◽  
Heat Treated ◽  
Data Points ◽  
Plasma Sprayed ◽  
High Degree

Elastic response behavior of four different plasma-sprayed deposits has been investigated using depth-sensing micro-indentation technique. Due to the high degree of porosity and inhomogeneity of the coatings, the characteristic elastic moduli were found to be in the range of 20–75% of that of the dense bulk material (200 GPa). Considering the wide variation of properties, 150 data points were generated with five different indentation loads for each coating, and statistical tools were employed to represent the scatter of the data. The characteristic elastic moduli of all the coatings were observed to be almost doubled when the magnitude of indentation load was reduced from the highest (1000 mN) to the lowest (30 mN). The coatings were subsequently heat treated at 1100 °C, the operational temperature of a gas turbine, for 2, 25, and 100 h, and in all the coating grades the corresponding elastic moduli increased significantly. However, the stiffening effect was not uniform in two grades and was more pronounced for the smaller indentation loads. The increase in elastic modulus is attributed to elimination of fine porosity and sintering neck formation, an assumption also supported by the results of mercury porosimetry.

scholarly journals Development and Testing of a Clear-Sky Data Selection Algorithm for FY-3C/D Microwave Temperature Sounder-2

2020 ◽  
Vol 12 (9) ◽  
pp. 1478 ◽  
Author(s):  
Zeyi Niu ◽  
Xiaolei Zou ◽  
Peter Sawin Ray
Keyword(s):  
Radial Distance ◽  
Mean Value ◽  
Data Selection ◽  
Selection Algorithm ◽  
Liquid Water Path ◽  
Model Simulations ◽  
Clear Sky ◽  
Brightness Temperatures ◽  
Data Points ◽  
Cloud Liquid Water Path

The Fengyun (FY)-3C/D microwave temperature sounder-2 (MWTS-2) is similar to the Advanced Microwave Sounding Unit-A (AMSU-A), except it lacks two window channels located at 23.8 GHz and 31.4 GHz. This makes a clear-sky data determination challenging for the MWTS-2 due to the unavailability of cloud liquid water path (LWP) retrievable from the two window channels. The purpose of this study is to develop a clear-sky data selection algorithm for the FY-3C/D MWTS-2 based on the bias-removed differences between observations and model simulations of the MWTS-2 50.3-GHz channel 1 (or equivalently AMSU-A channel 3). First, a point is defined as a temporal clear-sky (cloudy) point if the bias-removed difference between observed and simulated brightness temperatures is smaller than or equal to (greater than) 2 K. Then, a temporal clear-sky (cloudy) point is defined as a final clear-sky (cloudy) point if all points within its 60-km (100-km) radial distance are temporal clear-sky (cloudy) points. Finally, if the mean value of the bias-removed differences between observations and simulations in the 100-km circle from a temporal cloudy point are smaller than or equal to (greater than) 2 K, all temporal clear-sky points within this circle are (not) taken as the final clear-sky points. Applications of this algorithm to FY-3C MWTS-2 and MetOp-B AMSU-A lead to the following conclusions: (i) more than 70% (95%) of the clear-sky (cloudy) data points are successfully identified from both AMSU-A and MWTS-2 observations; (ii) the algorithm-selected clear-sky data points were located in clear-sky areas in the GOES-15 imager, and (iii) the bias-removed differences between observations and model simulations of MWTS-2 channel 1 well reveals the eye, the eyewall, and the spiral rainband structure of Super Typhoon Halong (2014).

ASM1 dynamic calibration and long-term validation for an intermittently aerated WWTP

2006 ◽  
Vol 53 (12) ◽  
pp. 247-256 ◽  
Author(s):  
A. Marquot ◽  
A.-E. Stricker ◽  
Y. Racault
Keyword(s):  
Treatment Plant ◽  
Simulation Software ◽  
Biological Nutrient Removal ◽  
Model Parameters ◽  
Dynamic Calibration ◽  
Biological Degradation ◽  
Data Set ◽  
Degree Of Confidence ◽  
High Degree

Activated sludge models, and ASM1 in particular, are well recognised and useful mathematical representations of the macroscopic processes involved in the biological degradation of the pollution carried by wastewater. Nevertheless, the use of these models through simulation software requires a careful methodology for their calibration (determination of the model parameters' values) and the validation step (verification with an independent data set). This paper presents the methodology and the results of dynamic calibration and validation tasks as a prior work to a modelling project for defining a reference guideline destined to French designers and operators. To reach these goals, a biological nutrient removal (BNR) wastewater treatment plant (WWTP) with intermittent aeration was selected and monitored for 2 years. Two sets of calibrated parameters are given and discussed. The results of the long-term validation task are presented through a 2-month simulation with lots of operation changes. Finally, it is concluded that, even if calibrating ASM1 with a high degree of confidence with a single set of parameters was not possible, the results of the calibration are sufficient to obtain satisfactory results over long-term dynamic simulation. However, simulating long periods reveals specific calibration issues such as the variation of the nitrification capacity due to external events.

The Optimum One-Dimensional Hydrodynamic Gas Rayleigh Step Bearing

1970 ◽  
Vol 92 (3) ◽  
pp. 504-508 ◽  
Author(s):  
G. M. Wylie ◽  
C. J. Maday
Keyword(s):  
Load Capacity ◽  
Slider Bearing ◽  
Optimum Configuration ◽  
Inherent Feature ◽  
Load Carrying ◽  
Lower Load ◽  
Data Points ◽  
Rayleigh Gas ◽  
Bearing Number ◽  
High Degree

The optimum Rayleigh gas slider bearing is determined for a range of bearing numbers. Numerical methods are used to calculate step location, step pressure, and load capacity for given values of step height ratio, bearing number, and flow parameter. These methods are used to determine as many data points as desired so that it is possible to obtain the optimum configuration dimensions to a very high degree of accuracy. An inherent feature of this analytical experiment is the acquisition of data pertaining to the near-optimum bearings and such data are presented for bearings with load capacities ranging down to seven-tenths of the load associated with the optimum Rayleigh bearing. At low bearing numbers it is found that the optimum Rayleigh bearing has only slightly lower load-carrying capability than the optimum gas slider bearing. For bearing numbers of 50, 100, and 500 the optimum Rayleigh slider bearings were, respectively, 5.8, 8.3, and 15.3 percent lower in load-carrying capability than the corresponding optimum bearings.

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