scholarly journals Precision and accuracy of modal analysis methods for clastic deposits and rocks: A statistical and numerical modeling approach

Geosphere ◽  
2021 ◽  
Author(s):  
Pierre-Simon Ross ◽  
Bernard Giroux ◽  
Benjamin Latutrie
Keyword(s):  
Modal Analysis ◽  
Cross Sections ◽  
Statistical Models ◽  
Normal Approximation ◽  
Numerical Models ◽  
Field Studies ◽  
Point Counts ◽  
Clastic Rocks ◽  
Analysis Methods ◽  
Precision And Accuracy

Quantifying the proportions of certain components in rocks and deposits (modal analysis or componentry) is important in earth sciences. Relevant methods for cross-sections (two- dimensional exposures) of clastic rocks include point counts or line counts. The accuracy of these methods has been supposed to be good in the literature but not necessarily verified empirically. Natural materials are inappropriate for assessing accuracy because the true proportions of each component are unknown. The precision of modal analysis methods has traditionally been evaluated from statistical models (primarily the normal approximation to the binomial distribution) but again rarely verified in practice because it is also extremely difficult to obtain different slices through the same material at outcrop scale. Here we create a set of numerical models of red and blue spheres with different proportions and sizes and cut 60 slices through the models, on which we perform point counts and line counts. We show that both of these methods are indeed able to retrieve the correct volumetric proportions of components, on average, when enough fragments are counted or intersected. As already known, precision is controlled by component abundance and the number of points counted or clasts intersected. However, we show that other important factors include differences between slices, which are relevant for our unequal-size models, and the proportion of voids, matrix, and/or cement in the rock. We present empirical precision charts for clast counts and line counts based on our models and make recommendations for future field studies.

scholarly journals Supplemental Material: Precision and accuracy of modal analysis methods for clastic deposits and rocks: A statistical and numerical modeling approach

2021 ◽  
Author(s):  
P.-S. Ross ◽  
et al.
Keyword(s):  
Numerical Modeling ◽  
Modal Analysis ◽  
Color Blindness ◽  
Modeling Approach ◽  
Analysis Methods ◽  
Precision And Accuracy

<div>File 1: Review of some previous studies and statistical concepts. File 2: Figures for people with color blindness.<br></div><div><br></div><div><br></div>

scholarly journals Supplemental Material: Precision and accuracy of modal analysis methods for clastic deposits and rocks: A statistical and numerical modeling approach

2021 ◽  
Author(s):  
P.-S. Ross ◽  
et al.
Keyword(s):  
Numerical Modeling ◽  
Modal Analysis ◽  
Color Blindness ◽  
Modeling Approach ◽  
Analysis Methods ◽  
Precision And Accuracy

<div>File 1: Review of some previous studies and statistical concepts. File 2: Figures for people with color blindness.<br></div><div><br></div><div><br></div>

scholarly journals Analysis of vibrodiagnostics methods in the technical state study of designed multimedia mobile scenes

2019 ◽  
Vol 302 ◽  
pp. 01011
Author(s):  
Marcin Łukasiewicz ◽  
Michał Liss ◽  
Natalia Dluhunovych
Keyword(s):  
Modal Analysis ◽  
Diagnostic Tests ◽  
Research Process ◽  
Technical Condition ◽  
Technical State ◽  
Normal Operation ◽  
Design Stage ◽  
Analysis Methods ◽  
State Study ◽  
Diagnostic Research

The paper presents the possibilities of using vibroacoustic methods in the study of the technical condition of designed multimedia mobile scenes. In particular, the possibility of implementing modal analysis methods in modelling and diagnostic research process has been presented. The use of virtual methods enables diagnostic tests both at the design stage and at the stage of normal operation, whereas modal methods help to explain the nature of the work of the element under investigation.

scholarly journals GEOLOGICAL AND GEOPHYSICAL CHARACTERISTICS OF THE ANABAR‐KHATANGA OIL AND GAS PROVINCE; NUMERICAL MODELING OF THE PROCESSES OF FORMATION OF SALT DOMES (SIBERIAN SECTOR OF THE RUSSIAN ARCTICS)

2019 ◽  
Vol 10 (2) ◽  
pp. 459-470
Author(s):  
V. A. Kontorovich ◽  
В. V. Lunev ◽  
V. V. Lapkovsky
Keyword(s):  
Cross Sections ◽  
Oil And Gas ◽  
Numerical Models ◽  
Sedimentary Cover ◽  
Ground Surface ◽  
Geological Structure ◽  
Salt Domes ◽  
Software Packages ◽  
Geological Features ◽  
Gas Bearing

The article discusses the geological structure, oil‐and‐gas‐bearing capacities and salt tectogenesis of the Anabar‐Khatanga saddle located on the Laptev Sea shore. In the study area, the platform sediments are represented by the 14‐45 km thick Neoproterozoic‐Mesozoic sedimentary complexes. The regional cross‐sections show the early and middle Devonian salt‐bearing strata and associated salt domes in the sedimentary cover, which may be indicative of potential hydrocarbon‐containing structures. Diapirs reaching the ground surface can be associated with structures capable of trapping hydrocarbons, and typical anticline structures can occur above the domes buried beneath the sediments. In our study, we used the algorithms and software packages developed by A.A. Trofimuk Institute of Petroleum Geology and Geophysics (IPGG SB RAS). Taking into account the structural geological features of the study area, we conducted numerical simulation of the formation of salt dome structures. According to the numerical models, contrasting domes that reached the ground surface began to form in the early Permian and developed most intensely in the Mesozoic, and the buried diapirs developed mainly in the late Cretaceous and Cenozoic.

scholarly journals Landbird Counting Techniques: Current Practices and an Alternative

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Steven S. Rosenstock ◽  
David R. Anderson ◽  
Kenneth M. Giesen ◽  
Tony Leukering ◽  
Michael F. Carter
Keyword(s):  
Distance Sampling ◽  
Field Studies ◽  
Empirical Models ◽  
Viable Alternative ◽  
Density Estimates ◽  
Abundance Index ◽  
Point Counts ◽  
Density Index ◽  
Conceptual Overview ◽  
Current Practices

AbstractCounting techniques are widely used to study and monitor terrestrial birds. To assess current applications of counting techniques, we reviewed landbird studies published 1989–1998 in nine major journals and one symposium. Commonly used techniques fell into two groups: procedures that used counts of bird detections as an index to abundance (index counts), and procedures that used empirical models of detectability to estimate density. Index counts rely upon assumptions concerning detectability that are difficult or impossible to meet in most field studies, but nonetheless remain the technique of choice among ornithologists; 95% of studies we reviewed relied upon point counts, strip transects, or other index procedures. Detectability-based density estimates were rarely used and deserve wider application in landbird studies. Distance sampling is a comprehensive extension of earlier detectability-based procedures (variable-width transects, variable circular plots) and a viable alternative to index counts. We provide a conceptual overview of distance sampling, specific recommendations for applying this technique to studies of landbirds, and an introduction to analysis of distance sampling data using the program DISTANCE.

Modal Analysis of Thin Walled Multi-Cell Multi-Tapered Composite Beams of Closed Cross Sections

2014 ◽  
Vol 629 ◽  
pp. 82-88 ◽  
Author(s):  
Sohail Ahmed ◽  
M.N. Ahmed
Keyword(s):  
Modal Analysis ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Aerospace Industry ◽  
Composite Beams ◽  
Wind Gust ◽  
Aircraft Wing ◽  
Model Accuracy ◽  
Finite Element Package ◽  
Thin Walled

This paper explicitly highlights the modal analysis of thin walled multi-cell multi-tapered composite beams in cantilever configurations, using MSC Patran / Nastran finite element package. Initially, the verification of the model was done with the analytical results in order to ensure the model accuracy. All the multi-tapered beams under examination are composed of closed section and three cell configuration. There is a vivid description of all the effects of composite material and stacking sequence on the modal frequencies. It also suggests the ways to shift the natural frequencies of the multi-tapered beams. This paper verifies the effects of different geometrical configurations of beams (tapered angles, lengths and point of variation of tapered angles) on the modal frequencies. This research is also useful in aerospace industry while designing the aircraft wing, which would experience the vibrations due to wind gust and engine cycles.

scholarly journals Modeling Assessment of Tidal Energy Extraction in the Western Passage

2020 ◽  
Vol 8 (6) ◽  
pp. 411
Author(s):  
Zhaoqing Yang ◽  
Taiping Wang ◽  
Ziyu Xiao ◽  
Levi Kilcher ◽  
Kevin Haas ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Three Dimensional ◽  
Energy Resource ◽  
Field Measurements ◽  
Tidal Energy ◽  
Resource Assessment ◽  
Ocean Model ◽  
Energy Extraction ◽  
Technical Specifications

Numerical models have been widely used for the resource characterization and assessment of tidal instream energy. The accurate assessment of tidal stream energy resources at a feasibility or project-design scale requires detailed hydrodynamic model simulations or high-quality field measurements. This study applied a three-dimensional finite-volume community ocean model (FVCOM) to simulate the tidal hydrodynamics in the Passamaquoddy–Cobscook Bay archipelago, with a focus on the Western Passage, to assist tidal energy resource assessment. IEC Technical specifications were considered in the model configurations and simulations. The model was calibrated and validated with field measurements. Energy fluxes and power densities along selected cross sections were calculated to evaluate the feasibility of the tidal energy development at several hotspots that feature strong currents. When taking both the high current speed and water depth into account, the model results showed that the Western Passage has great potential for the deployment of tidal energy farms. The maximum extractable power in the Western Passage was estimated using the Garrett and Cummins method. Different criteria and methods recommended by the IEC for resource characterization were evaluated and discussed using a sensitivity analysis of energy extraction for a hypothetical tidal turbine farm in the Western Passage.

The use of Runoff and Surface Water Transport and Fate Models in the Pesticide Registration Process

1992 ◽  
Vol 6 (3) ◽  
pp. 743-748 ◽  
Author(s):  
Paul L. Zubkoff
Keyword(s):  
Surface Waters ◽  
Environmental Fate ◽  
Transport Model ◽  
Numerical Models ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Fate And Transport ◽  
Environmental Parameters ◽  
Field Studies ◽  
Chemical Application

In support of the registration and reregistration processes under FIFRA ‘88, numerical models are used to estimate the dissolved runoff and soil erosion loadings of pesticides to surface waters and the subsequent fate and transport of pesticides in the receiving waters. Uses for simulations include:1. Helping to determine whether additional studies on the fate and distribution of a candidate chemical in the environment and/or ecological effects may be needed when full chemical characterization is incomplete.2. Helping to more fully integrate data submissions of laboratory and field observations.3. Estimating probable fate and distribution of an agrochemical after a severe runoff event.4. Comparing alternative chemical application rates and methods for the same chemical/soil/crop/environmental combinations.5. Comparing different soil/crop/environmental combinations representing different geographical areas with the same chemical.6. Evaluating preliminary designs of proposed field studies.7. Gaining insight into the environmental fate of modern chemicals that are applied at 1 to 2% of the rates of older chemicals when sampling designs and analytical methods are not available.The Office of Pesticide Programs (OPP) commonly employs the SWRRB (45, 46) and PRZM (8, 9) models for runoff and EXAMS II (5), a fate and transport model, for surface waters. These three models are used in conjunction with appropriate databases for soils, chemical properties, and meteorological and other environmental parameters. Registrants are encouraged to clearly state assumptions, identify values for parameters by citation, report results of simulations with summary tables and graphics, and interpret their results in relation to current scientific disciplines.

Application of Approximated Modal Analysis Methods for PLC System Design

1987 ◽  
Vol 2 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Jose Luis Naredo ◽  
Jose Luis Silva ◽  
Ricardo Romero ◽  
Pablo Moreno
Keyword(s):  
System Design ◽  
Modal Analysis ◽  
Analysis Methods

Towards a process-based model to predict dune erosion along the Dutch Wadden coast

2012 ◽  
Vol 91 (3) ◽  
pp. 357-372 ◽  
Author(s):  
B.G. Ruessink ◽  
M. Boers ◽  
P.F.C. van Geer ◽  
A.T.M. de Bakker ◽  
A. Pieterse ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Current Knowledge ◽  
Numerical Models ◽  
Field Studies ◽  
Breaking Waves ◽  
Sand Transport ◽  
Breaking Wave ◽  
Field Observations ◽  
Erosion Model ◽  
Dune Erosion

AbstractAn equilibrium dune-erosion model is used every six years to assess the capability of the most seaward dune row on the Dutch Wadden islands to withstand a storm with a 1 in 10,000 probability for a given year. The present-day model is the culmination of numerous laboratory experiments with an initial cross-shore profile based on the central Netherlands coast. Large parts of the dune coast of the Wadden islands have substantially different dune and cross-shore profile characteristics than found along this central coast, related to the presence of tidal channels, ebb-tidal deltas, beach-plains and strong coastal curvature. This complicated coastal setting implies that the predictions of the dune-erosion model are sometimes doubtful; accordingly, a shift towards a process-based dune-erosion model has been proposed. A number of research findings based on recent laboratory and field studies highlight only few of the many challenges that need to be faced in order to develop and test such a model. Observations of turbulence beneath breaking waves indicate the need to include breaking-wave effects in sand transport equations, while current knowledge of infragravity waves, one of the main sand transporting mechanisms during severe storm conditions, is strongly challenged by laboratory and field observations on gently sloping beaches that are so typical of the Wadden islands. We argue that in-situ and remote-sensing field observations, laboratory experiments and numerical models need to be the pillars of Earth Scientific research in the Wadden Sea area to construct a meaningful process-based dune-erosion tool.

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