Complete High Dimensional Inverse Characterization of Fractal Surfaces

Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos

The present paper describes a methodology for the inverse identification of the complete set of parameters associated with the Weirstrass-Mandelbrot (W-M) function that can describe any rough surface known by its profilometric or topographic data. Our effort is motivated by the need to determine the mechanical, electrical and thermal properties of contact surfaces between deformable materials that conduct electricity and heat and require an analytical representation of the surfaces involved. Our method involves utilizing a refactoring of the W-M function that permits defining the characterization problem as a high dimensional singular value decomposition problem for the determination of the so-called phases of the function. Coupled with this process is a second level exhaustive search that enables the determination of the density of the frequencies involved in defining the trigonometric functions involved in the definition of the W-M function. Our approach proves that this is the only additional parameter that needs to be determined for full characterization of the W-M function as the rest can be selected arbitrarily. Numerical applications of the proposed method on both synthetic and actual elevation data, validate the efficiency and the accuracy of the proposed approach. This approach constitutes a radical departure from the traditional fractal dimension characterization studies and opens the road for a very large number of applications.

Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos

In the present paper, we are describing a methodology for the determination of the complete set of parameters associated with the Weierstrass-Mandelbrot (W-M) function that can describe a fractal scalar field distribution defined by measured or computed data distributed on a surface or in a volume. Our effort is motivated not only by the need for accurate fractal surface and volume reconstruction but also by the need to be able to describe analytically a scalar field quantity distribution on a surface or in a volume that corresponds to various material properties distributions for engineering and science applications. Our method involves utilizing a refactoring of the W-M function that permits defining the characterization problem as a high dimensional inverse problem solved by singular value decomposition for the so-called phases of the function. Coupled with this process is a second level exhaustive search that enables the determination of the density of the frequencies involved in defining the trigonometric functions participating in the definition of the W-M function. Numerical applications of the proposed method on both synthetic and actual surface and volume data, validate the efficiency and the accuracy of the proposed approach. This approach constitutes a radical departure from the traditional fractal dimension characterization studies and opens the road for a very large number of applications.


Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos

The present paper describes a methodology for the inverse identification of the complete set of parameters associated with the Weirstrass-Mandelbrot (W-M) function that can describe any fractal scalar field distribution of measured data defined within a volume. Our effort is motivated by the need to be able to describe a scalar field quantity distribution in a volume in order to be able to represent analytically various non-homogeneous material properties distributions for engineering and science applications. Our method involves utilizing a refactoring of the W-M function that permits defining the characterization problem as a high dimensional singular value decomposition problem for the determination of the so-called phases of the function. Coupled with this process is a second level exhaustive search that enables the determination of the density of the frequencies involved in defining the trigonometric functions involved in the definition of the W-M function. Numerical applications of the proposed method on both synthetic and actual volume data, validate the efficiency and the accuracy of the proposed approach. This approach constitutes a radical departure from the traditional fractal dimension characterization studies and opens the road for a very large number of applications and generalizes the approach developed by the authors for fractal surfaces to that of fractal volumes.


Author(s):  
Diana Spiegelberg ◽  
Jonas Stenberg ◽  
Pascale Richalet ◽  
Marc Vanhove

AbstractDesign of next-generation therapeutics comes with new challenges and emulates technology and methods to meet them. Characterizing the binding of either natural ligands or therapeutic proteins to cell-surface receptors, for which relevant recombinant versions may not exist, represents one of these challenges. Here we report the characterization of the interaction of five different antibody therapeutics (Trastuzumab, Rituximab, Panitumumab, Pertuzumab, and Cetuximab) with their cognate target receptors using LigandTracer. The method offers the advantage of being performed on live cells, alleviating the need for a recombinant source of the receptor. Furthermore, time-resolved measurements, in addition to allowing the determination of the affinity of the studied drug to its target, give access to the binding kinetics thereby providing a full characterization of the system. In this study, we also compared time-resolved LigandTracer data with end-point KD determination from flow cytometry experiments and hypothesize that discrepancies between these two approaches, when they exist, generally come from flow cytometry titration curves being acquired prior to full equilibration of the system. Our data, however, show that knowledge of the kinetics of the interaction allows to reconcile the data obtained by flow cytometry and LigandTracer and demonstrate the complementarity of these two methods.


Author(s):  
Yves Balasko

The global coordinate system for the equilibrium manifold follows from: (1) the determination of the unique fiber F(b) through the equilibrium (ρ‎, ω‎) where b = φ‎((ρ‎, ω‎) = (ρ‎, ρ‎ · ρ‎1, …, ρ‎ · ρ‎m); and (2) the determination of the location of the equilibrium (ρ‎, ω‎) within the fiber F(b) viewed as a linear space of dimension (ℓ − 1)(m − 1) and, therefore, parameterized by (ℓ − 1)(m − 1) coordinates. If there is little leeway in determining the fiber F(b) through the equilibrium (ρ‎, ω‎), there are different ways of representing the equilibrium (ρ‎, ω‎) within its fiber F(b). This leads to the definition of coordinate systems (A) and (B) for the equilibrium manifold. This chapter defines these two coordinate systems and applies them to obtain an analytical characterization of the critical equilibria, i.e., the critical points of the natural projection.


Author(s):  
Danilo Machado Lawinscky da Silva ◽  
Rodrigo Almeida Bahiense ◽  
Breno Pinheriro Jacob ◽  
Fernando Gomes da Silva Torres ◽  
Antonio Roberto Medeiros ◽  
...  

Conventional offshore pipeline installation operations in Brazil have been performed in an S-Lay procedure employing the BGL-1 barge, owned by Petrobras. However, this procedure has some limits, and may not be feasible in some particular scenarios. Therefore, the objective of this work is to present the numerical simulation of an alternative pipeline installation procedure. This procedure basically consists of performing the pipeline assembly on shore, and deflecting it to the sea using a tug boat. The numerical simulations employ the SITUA-Prosim computational tool, which is able to incorporate the correct definition of the seabed and shore from bathymetric curves. An actual pipeline installation by this lateral deflection procedure is analyzed and discussed. The characterization of the procedure passes through the determination of the better velocity and direction of the tug boat in order to minimize the efforts on the pipeline (especially due to the curvatures).


Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos

Motivated by the need to determine the mechanical, electrical and thermal properties of contact surfaces between deformable materials that conduct electricity and heat, we are presenting here a method for characterizing certain topological characteristics of rough surfaces. The inverse identification of a set of parameters associated with the parametric representation of any rough surface based on profilometric data is described in contrast with the standard one parameter approaches. The description of the surface topography parametrization is first given in terms of a function that enables the generation of synthetic data. Objective functions are created based on both the profilometric evaluations of the parametric representation of the surface as well as its power spectrum. A statistical Monte Carlo based optimization method is implemented for determining the characteristic parameters needed for further analysis that leads to the determination of other physical properties of the surface. Numerical application of the method validates the efficiency and the accuracy of the proposed approach.


Author(s):  
Mykola Lykhostup ◽  
◽  
Yuriy Varfolomeev ◽  

The constant aspiration of a person to replace manual labor with the work of machines and mechanisms is reproduced in such concepts as "mechanization", "automation", "machine-tool" and others. In the construction industry, the most common and most favorable for the disclosure of this desire is an indicator of the level of mechanization. But in the techniques and recommendations that provide advice on the definition of this indicator, its calculation is carried out using generalizations of mechanization of labor without giving any clear representations as to the determination of production volumes in a purely mechanized way.The article reveals the essence of the indicator of the level of mechanization of road production, which determines the expediency of improving the structure of the main production assets of the enterprise for the implementation of such a program of work, which would contribute to maximizing profits. In general, the definition of the rational level of mechanization is based on the implementation of an iterative algorithm, which includes a number of stages.Thus, at the first stage, the initial (basic) program of a road organization is determined using data on the quantity and quality of the main production assets and the usual program of work for this enterprise. Determining the structure of this program, consisting of a number of road works and labor processes, in turn, is carried out using the developed algorithm, which involves the maximum technological use of all types of resources, including technical, which contribute to the mechanized mode of work. Next, using the data on the structure of the works, it is possible to obtain the estimated value of profit that can be obtained as a result of the implementation of the initial program of work. On the basis of the information about the estimated value of profit formed part of it in the form of a production development fund. The size of the fund for the development of production is the basis for reforming the machine park of the road organization. Options for changing the quantitative and qualitative composition of the machine park include the steps to assess their residual value, the purchase of new machines, major repairs or replacement of existing units of equipment. Using the data of various variants of the modernization of the park of machines and mechanisms, the corresponding changes for working hours for them are determined for the year, that is, the initial annual of working time is recalculated. The updated information on annual working time funds is used to determine the appropriate modifications to the park of machines of the work program of the road organization. For each option of updated programs of work determined by the calculated profit, and its maximum value is approved rational program of work. At the last stage, using data on total costs of manual and mechanized labor, as well as data on the total number of performers, indicators are calculated that characterize the level of mechanization of a road enterprise. The obtained indicators, as characteristics of the level of mechanization, can be used to solve various tasks in the field of road production management.


2015 ◽  
Vol 8 (4) ◽  
pp. 491-506
Author(s):  
J. A. DE CARVALHO NETO ◽  
L. A. C. M. VELOSO

AbstractThe knowledge on the active moving load of a bridge is crucial for the achievement of the information on the behavior of the structure, and thus foresee maintenance, repairs and better definition of the logistics of its active vehicles. This paper presents the development of the algorithms for the application of the Bridge-Weigh In Motion (B-WIM) method created by Moses for the weighing of trains during motion and also for the characterization of the rail traffic, allowing the obtainment of information like passage's train velocity and number and spacing of axles, eliminating the dynamic effect. There were implemented algorithms for the determination of the data referring to the geometry of the train and its loads, which were evaluated using a theoretical example, in which it was simulated the passage of the train over a bridge and the loads of its axles were determined with one hundred percent of precision. In addition, it was made a numerical example in finite elements of a reinforced concrete viaduct from the Carajás' Railroad, in which the developed system reached great results on the characterization and weighing of the locomotive when the constitutive equation of the Brazilian Standards was substituted by the one proposed by Collins and Mitchell.


Author(s):  
Denis Grishin ◽  
Mariya Vilacheva ◽  
Irina Soshnikova

In the academic and educational criminal and legal literature, special attention is paid to crimes committed on rail transport. The statistics provided by the official website of the Prosecutor General’s Office of the Russian Federation confirms that the majority of these crimes are thefts. In the study, the issues of characterization of these crimes are analyzed, as well as their elements. Particular attention is paid to the subject of the crime: in most crimes it is special, and this also affects the characterization of such theft. Given the variability of approaches to qualifying of thefts, the authors propose their own definition of such theft. The methods of investigation of the above-mentioned thefts are examined. The authors cite various investigative situations arising on different stages of investigation and note that the characterization of theft of cargo of railway rolling stock, as well as determination of the range of people potentially involved in the crime, depends on where, when and how it was committed, what are the amount and the value of the property stolen, and whether the crimes are multiple.


Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 499 ◽  
Author(s):  
Toshiyuki Sasaki ◽  
Mikiji Miyata

A β-strand is a component of a β-sheet and is an important structural motif in biomolecules. An α-helix has clear helicity, while chirality of a β-strand had been discussed on the basis of molecular twists generated by forming hydrogen bonds in parallel or non-parallel β-sheets. Herein we describe handedness determination of two-fold helicity in a zig-zag β-strand structure. Left- (M) and right-handedness (P) of the two-fold helicity was defined by application of two concepts: tilt-chirality and multi-point approximation. We call the two-fold helicity in a β-strand, whose handedness has been unrecognized and unclarified, as hidden chirality. Such hidden chirality enables us to clarify precise chiral characteristics of biopolymers. It is also noteworthy that characterization of chirality of high dimensional structures like a β-strand and α-helix, referred to as high dimensional chirality (HDC) in the present study, will contribute to elucidation of the possible origins of chirality and homochirality in nature because such HDC originates from not only asymmetric centers but also conformations in a polypeptide chain.


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