scholarly journals Estimation of the Cartographic Projection and~its Application in Geoinformatics-habilitation thesis presentation

2017 ◽  
Vol 16 (1) ◽  
pp. 17-52 ◽  
Author(s):  
Tomáš Bayer
Keyword(s):  
Pole Position ◽  
Distance Functions ◽  
Small Scale ◽  
Central Meridian ◽  
Unknown Parameters ◽  
Map Projection ◽  
Geometric Reconstruction ◽  
Sphere Radius ◽  
Habilitation Thesis ◽  
Map Analysis

<div class="abstract"><div class="abstract_item"><em>Modern techniques for the map analysis allow for the creation of full or partial geometric reconstruction of its content. The projection is described by the set of estimated constant values: transformed pole position, standard parallel latitude, longitude of the central meridian, and a constant parameter. Analogously the analyzed map is represented by its constant values: auxiliary sphere radius, origin shifts, and angle of rotation. Several new methods denoted as M6-M9 for the estimation of an unknown map projection and its parameters differing in the number of determined parameters, reliability, robustness, and convergence have been developed. However, their computational demands are similar. Instead of directly measuring the dissimilarity of two projections, the analyzed map in an unknown projection and the image of the sphere in the well-known (i.e., analyzed) projection are compared. Several distance functions for the similarity measurements based on the location as well as shape similarity approaches are proposed. An unconstrained global optimization problem poorly scaled, with large residuals, for the vector of unknown parameters is solved by the hybrid BFGS method. To avoid a slower convergence rate for small residual problems, it has the ability to switch between first- and second-order methods. Such an analysis is beneficial and interesting for historic, old, or current maps without information about the projection. Its importance is primarily referred to refinement of spatial georeference for the medium- and small-scale maps, analysis of the knowledge about the former world, analysis of the incorrectly/inaccurately drawn regions, and appropriate cataloging of maps. The proposed algorithms have been implemented in the new version of the <span style="font-family: monospace;">detectproj</span> software.</em></div></div>

A CANADIAN GRID SYSTEM IN 3° TRANSVERSE MERCATOR ZONES

1964 ◽  
Vol 18 (2) ◽  
pp. 147-155
Author(s):  
J. Saastamoinen
Keyword(s):  
Free Choice ◽  
Metropolitan Areas ◽  
Central Meridian ◽  
Conformal Map ◽  
Grid System ◽  
Order Accuracy ◽  
Map Projection ◽  
First Order ◽  
The Subject ◽  
Local Plane

All geodetic networks that rest previously fixed control are best computed in plane coordinates. Under this category fall a great deal of first-order triangulation and, of course, the whole volume of lower-order work—all the way down to the last monuments from which detail surveys originate. A geodetic grid must be designed to meet first-order accuracy and should be established on federal rather than provincial level. Its use requires precomputed tables based on some conformal map projection, preferably the Transverse Mercator (Gauss-Krüger) projection. Congruent projection zones, simple scale factor, free choice of central meridian for local plane coordinates in cities and metropolitan areas—all these features of the Transverse Mercator find no parallel in any other map projection. Following a brief introduction to the subject, a set of tables for a proposed Canadian grid system is presented.

Online Prediction of Transient Instability by Wide Area Measurement System

2016 ◽  
Vol 1 (1) ◽  
pp. 31
Author(s):  
Farhad Namdari ◽  
Maryam Nourizadeh ◽  
Mahmoodreza Shakarami
Keyword(s):  
New England ◽  
Prediction Method ◽  
Test System ◽  
Least Square ◽  
Area Measurement ◽  
Wide Area ◽  
Small Scale ◽  
Unknown Parameters ◽  
Wide Area Measurement System ◽  
Real Time Simulations

<p>In this paper an online accurate prediction method is proposed to enhance the speed of Transactionient stability assessment. This method is the measurement basis technique resulted from wide area measurement systems (WAMS). In the proposed method, the generators with same dynamic behavior, referred as to coherent generators, are clustered as a same group and they can be considered as an equivalent bus. So the system will be reduced into a small scale system. The admittance matrix parameters of the reduced system can be identified with the least square algorithm. Then the trajectory prediction is performed by real-time simulations. Obtained results from simulations on New England test system show the high noticeable efficiency for performance of the proposed method, capable in predicting of the disturbed trajectory under existence of unknown parameters in grid structure.. </p>

Research and Design of In-Arm Torsional Electromagnetic Active Suspension

2019 ◽  
Author(s):  
Chengleng Han ◽  
Lin Xu ◽  
Mohamed A. A. Abdelkareem ◽  
Enkang Cui ◽  
Junyi Zou ◽  
...  
Keyword(s):  
Characteristic Curve ◽  
Body Height ◽  
Active Suspension ◽  
Small Scale ◽  
Unknown Parameters ◽  
Body Attitude ◽  
New Type ◽  
Stiffness And Damping ◽  
The Mathematical Model ◽  
Research And Design

Abstract This paper introduced a new type of an active suspension named as In-Arm Torsional Electromagnetic Active Suspension (ITEAS) according to its suspension characteristics. The proposed ITEAS is capable of actively controlling body attitude and adjusting the stiffness and damping of a suspension system in a larger scale. The structure of the ITEAS system is composing of a mechanical displacement adjustment device, a two-chamber vane damper connected by an electromagnetic valve, two torsion bars and necessary connection units such as trailing arms. Based on the hydraulic theory and fluid mechanics, the mathematical model of the vane damper was established and the external characteristic curve of the damper was obtained through the simulations. Regarding to the ITEAS stiffness and damping analysis, a quarter dynamic vehicle model was established and simulated by the AMESim platform. The results showed that the automobile ride based on the ITEAS system was reasonable as well as the functions of body height adjustment and suspension controllability were available. Thereafter, a small-scale prototype has been built to calibrate the unknown parameters for further research on ITEAS.

Development of mathematical model Gauss – Kruger coordinate system for calculating planimetric rectangular coordinates using geodesic coordinates

2017 ◽  
Vol 926 (8) ◽  
pp. 10-19 ◽  
Author(s):  
P.A. Medvedev ◽  
M.V. Novgorodskaya
Keyword(s):  
Coordinate System ◽  
Convergent Series ◽  
Central Meridian ◽  
Rectangular Coordinates ◽  
Calculation Algorithms ◽  
In Series ◽  
Sphere Radius ◽  
Plane Projection ◽  
The Difference ◽  
Definition Of

Algorithms with improved convergence for the calculation of rectangular coordinates in the Gauss – Kruger coordinate system according to the parameters of any ellipsoid were designed. The approach of definition the spherical components in the classic series defined variables x, y, represented by the difference between the degrees of longitude l, followed by the replacement of their sums by formulas of spherical trigonometry. For definition of the amounts of spherical components of the relevant decompositions patterns of transverse-cylindrical sphere plane projection in the condition of the initial data equality on the ellipsoid and sphere radius N were used. Analysis of othertransformation methods of classical expansions in series, used in derivation of both logarithmical and non-logarithmical working formulas is carried outfor comparison with developed algorithms. The technique of algorithms development with usage of hyperbolic tangent function, applied by L. Kruger, Yu. Karelin, A. Schödlbauer is considered and their analysis is carried out. Advantages of Krasovskii – Isotov formulas for six-degree strips are pointed out. The usage of the spherical function sin τ in the expansion made it possible not only to obtain a rapidly convergent series, but also to represent the spherical part of the solution of the problem with the help of trigonometric identities in different types. It is proved that derived for the calculation algorithms with the proposed estimates of their accuracy, are optimal in removing points from the central meridian to l ≤ 6°. For the difference of longitudes l > 6°, the expansions of the unknown quantities into Fourier series should be applied. An example of the calculation of coordinates in the system SK-2011 is given. Theoretical studies have been carried out and shortened formulas with a reliability estimate for the determination of coordinates in the area l ≤ 3° have been proposed.

scholarly journals Adaptive tracking control based on neural approximation for the yaw motion of a small-scale unmanned helicopter

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141982827 ◽  
Author(s):  
Tri-Quang Le ◽  
Ying-Chih Lai ◽  
Chun-Liang Yeh
Keyword(s):  
Tracking Control ◽  
Fuzzy Logic Controller ◽  
Adaptive Controller ◽  
Current Approach ◽  
Small Scale ◽  
Unmanned Helicopter ◽  
Discrete Time System ◽  
Unknown Parameters ◽  
Adaptive Tracking Control ◽  
Marquardt Algorithm

This article aims to study a solution that can solve the problem of tracking control for yaw motion of an unmanned helicopter. The non-affine nonlinear equation is converted to a simplified affine model. The unknown parameters are estimated by the Levenberg–Marquardt algorithm. An autonomous flight controller is developed with the Lyapunov-based adaptive controller for a discrete-time system. For flight data collection and verification purpose, the software-in-the-loop is constructed based on Simulink and X-Plane simulator. The designed system is applied in the control of the yaw motion of an R30 V2 helicopter under ideal and turbulent environments. The performance of the proposed method is compared with the fuzzy logic controller, and the simulation results show that the quality of the current approach is considerably better.

High-Performance Small-Scale Raster Map Projection Empowered by Cyberinfrastructure

2018 ◽  
pp. 171-188
Author(s):  
Michael P. Finn ◽  
Yan Liu ◽  
David M. Mattli ◽  
Babak Behzad ◽  
Kristina H. Yamamoto ◽  
...  
Keyword(s):  
High Performance ◽  
Small Scale ◽  
Map Projection

scholarly journals Bayesian estimation of the hydraulic and solute transport properties of a small-scale unsaturated soil column

2016 ◽  
Vol 64 (1) ◽  
pp. 30-44 ◽  
Author(s):  
Paulo H. S. Moreira ◽  
Martinus Th. van Genuchten ◽  
Helcio R. B. Orlande ◽  
Renato M. Cotta
Keyword(s):  
Solute Transport ◽  
Transport Properties ◽  
Unsaturated Soil ◽  
Soil Column ◽  
Column Experiment ◽  
Richards Equation ◽  
Small Scale ◽  
Transport Parameters ◽  
Unknown Parameters ◽  
Concentration Data

Abstract In this study the hydraulic and solute transport properties of an unsaturated soil were estimated simultaneously from a relatively simple small-scale laboratory column infiltration/outflow experiment. As governing equations we used the Richards equation for variably saturated flow and a physical non-equilibrium dual-porosity type formulation for solute transport. A Bayesian parameter estimation approach was used in which the unknown parameters were estimated with the Markov Chain Monte Carlo (MCMC) method through implementation of the Metropolis-Hastings algorithm. Sensitivity coefficients were examined in order to determine the most meaningful measurements for identifying the unknown hydraulic and transport parameters. Results obtained using the measured pressure head and solute concentration data collected during the unsaturated soil column experiment revealed the robustness of the proposed approach.

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