Visualizing Methods of Multi-criteria Alternatives for Pairwise Comparison Procedure

Author(s):  
Alena Zaharova ◽  
Dmitriy Aleksandrovich Korostelev

The article deals with the problem of choosing a preferred alternative in a pairwise comparison procedure. The difficulties of applying this procedure in a case of using alternatives with a large number of criteria are noted. It is proposed to supplement the procedure of expert pairwise comparison with visualization tools of multi-criteria alternatives. The paper considers several visualization methods for multi-criteria alternatives for pairwise comparison procedures: histograms, two-dimensional graphs, three-dimensional surfaces, probability distribution diagrams, visualization based on modifications of radar and radial diagrams, as well as combined methods. It described an experimental study of the application of the considered method for the task of determining the preferred alternative by the example of choosing one of two OpenFoam solvers (rhoCentralFoam and pisaCentralFoam), with the help of which estimates of the accuracy of calculating the inviscid flow around a cone were obtained. Each solver is characterized by 288 criteria. It is shown that the use of some of the methods considered does not make it possible for the expert to make a choice. In this case, a good result was obtained using methods for constructing three-dimensional surfaces, probability distribution diagrams, as well as using the combined method based on modified radar diagrams. It is concluded that the rhoCentralFoam solver is more preferable if there are no additional criteria for ranking the criteria. The possibility of using the combined method in combination with the ranking procedure of criteria (or their groups) during decision-making is also noted.

This paper describes an experimental study of the drag of two- and three-dimensional bluff obstacles of various cross-stream shapes when towed through a fluid having a stable, linear density gradient with Brunt-Vaisala frequency, N . Drag measurements were made directly using a force balance, and effects of obstacle blockage ( h / D , where h and D are the obstacle height and the fluid depth, respectively) and Reynolds number were effectively eliminated. It is shown that even in cases where the downstream lee waves and propagating columnar waves are of large amplitude, the variation of drag with the parameter K ( = ND /π U ) is qualitatively close to that implied by linear theories, with drag minima existing at integral values of K . Under certain conditions large, steady, periodic variations in drag occur. Simultaneous drag measurements and video recordings of the wakes show that this unsteadiness is linked directly with time-variations in the lee and columnar wave amplitudes. It is argued that there are, therefore, situations where the inviscid flow is always unsteady even for large times; the consequent implications for atmospheric motions are discussed.


2010 ◽  
Vol 24 (1) ◽  
pp. 23-42 ◽  
Author(s):  
T. S. Amer ◽  
Sury Ravindran

ABSTRACT: Graphical displays of business and accounting information are widely used as decision aids. Theoretical work in visual perception indicates graphs that exhibit certain characteristics create visual illusions that may result in biased decision making. This paper reports the results of an experiment that demonstrates how such two-dimensional and three-dimensional visual illusions cause viewers to make biased comparison judgments. The experiment also shows that these decision biases can be mitigated by including gridlines in both two- and three-dimensional graphs.


2019 ◽  
Vol 43 (4) ◽  
pp. 653-660 ◽  
Author(s):  
M.V. Gashnikov

Adaptive multidimensional signal interpolators are developed. These interpolators take into account the presence and direction of boundaries of flat signal regions in each local neighborhood based on the automatic selection of the interpolating function for each signal sample. The selection of the interpolating function is performed by a parameterized rule, which is optimized in a parametric lower dimensional space. The dimension reduction is performed using rank filtering of local differences in the neighborhood of each signal sample. The interpolating functions of adaptive interpolators are written for the multidimensional, three-dimensional and two-dimensional cases. The use of adaptive interpolators in the problem of compression of multidimensional signals is also considered. Results of an experimental study of adaptive interpolators for real multidimensional signals of various types are presented.


2019 ◽  
Vol 11 (7) ◽  
pp. 577-583 ◽  
Author(s):  
Aleksey Barkhatov ◽  
Evgenii Vorobev ◽  
Vladimir Veremyev ◽  
Vladimir Kutuzov

This article presents the configuration and technical specification of the passive radar exploiting third-party transmitters of second-generation digital video broadcasting standard DVB-T2 as illuminators of opportunity. The performance of the two-dimensional (2D) passive radar estimated based on theoretical and experimental study is described. The possible configuration of the 2D non-equidistant antenna array for the three-dimensional (3D) passive radar is proposed to ensure the 3D localization of detected targets. The experimental results on drone detection conducted with the 3D passive radar show that the radar with the 2D antenna array is capable to measure not only azimuth but also elevation and consequently target altitude.


Author(s):  
Yujia Liu ◽  
Sifan Peng ◽  
Nan Gui ◽  
Xingtuan Yang ◽  
Jiyuan Tu ◽  
...  

Abstract The pebbles flow is a fundamental issue for both academic investigation and engineering application in reactor core design and safety analysis. In general, experimental methods including spiral X-ray tomography and refractive index matched scanning technique (RIMS) are applied to obtain the identification of particles’ positions within a three-dimensional pebble bed. However, none of the above methods can perform global bed particles’ position identification in a dynamically discharging pebble bed, and the corresponding experimental equipment is difficult to access due to the complication and high expense. In this research, the experimental study is conducted to observe the gravity driven discharging process in the quasi two-dimensional silos by making use of the high-speed camera and the uniform backlight. A mathematical morphology-based method is applied to the pre-processing of the captured results. After being increased the gray value gradient by the threshold segmentation, the edges of the particles are identified and smoothed by the Sobel algorithm and the morphological opening operation. The particle centroid coordinates are identified according to the Hough circle transformation of the edges. For the whole pebble bed, the self-programmed process has a particle recognition accuracy of more than 99% and a particle centroid position deviation of less than 3%, which can accurately obtain the physical positions of all particles in the entire dynamically discharge process. By analyzing the position evolution of individual particles in consecutive images, velocity field and motion events of particles are observed. The discharging profiles of 5 conditions with different exit are analyzed in this experiment. The results make a contribution to improving the understanding of the mechanism of pebbles flow in nuclear engineering.


1979 ◽  
Vol 101 (4) ◽  
pp. 500-505 ◽  
Author(s):  
J. H. Strickland ◽  
B. T. Webster ◽  
T. Nguyen

An aerodynamic prediction model has been formulated for two- and three-dimensional Darrieus turbines using a vortex lattice method of analysis. Experiments were conducted on a series of two-dimensional rotor configurations in a water tow tank. The agreement between analysis and experiment was in general found to be good. This model should allow one to make accurate predictions of instantaneous aerodynamic blade forces and to characterize the near wake flow behind the rotor.


1984 ◽  
Vol 1 (19) ◽  
pp. 151 ◽  
Author(s):  
J. Buhr Hansen ◽  
I.A. Svendsen

It is well known that on a three-dimensional beach large volumes of water carried shorewards by the breakers feed longshore currents, which eventually escape back through the breaker line, often as rip currents. In a steady two-dimensional situation, however, the mass flux represented by (among other things) the surface roller in the breakers returns as a seaward current close to the bottom. This current is called the undertow. In this paper theoretical results for the undertow are compared with the results of recent laboratory experiments.


2000 ◽  
Vol 23 (1) ◽  
pp. 37-51
Author(s):  
C. R. Tellier ◽  
T. G. Leblois ◽  
A. Charbonnieras

This paper deals with the anisotropic chemical etching of various silicon plates etched in EDP. Changes with orientation in geometrical features of etched surface and in the etching shape of starting circular sections are systematically investigated. These etching shapes are compared with shapes produced by etching in KOH and TMAH solutions; This experimental study allows us to determine the dissolution slowness surface for the EDP solution and to investigate the real influence of the etchant on two dimensional and three dimensional etching shapes.


An experimental study has been made of some aspects of the phenomena accompanying the collapse of liquid columns on to a rigid horizontal plane with air as the outer medium. The cases covered include the two-dimensional collapse of rectangular and semicircular sections, and the three-dimensional axial collapse of right circular cylinders. As the columns collapsed, the fluid spread across the horizontal plane, attaining a maximum velocity, which, in the two-dimensional cases, was proportional to the square root of the original height. It was not clear whether this proportionality would hold for the axial collapse of cylinders. If it did, then the factor of proportionality would be some 25 % lower. In the two-dimensional cases the top of the residual column accelerated downwards to a maximum velocity proportional to the square root of the product of the original height and the original height to base ratio. The nature of the subsequent retardation indicated that the downward velocity probably approached zero asymptotically with time.


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