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Number of results: 6
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Abstract

In the framework of the 4th International Polar Year Panel “Plate Tectonics and Polar Gateways” the international project “The Dynamic Continental Margin Between the Mid-Atlantic-Ridge System (Mohns Ridge, Knipovich Ridge) and the Bear Island Region” was undertaken in 2007-2008. As a part of this project a new three-component seismic broadband station was installed in September 2007 in the area of the Polish Polar Station Hornsund in Southern Spitsbergen . The new HSPB station has the coordinates: Φ = 77.0019°N, λ = 15.5332°E, H = 11 m a.s.l. During the first years of operation a number of good quality teleseismic events were recorded. This gives the opportunity for a first determination of crustal and mantle structure beneath the station by using receiver function (RF) and SKS splitting techniques. The Moho depth determined using RF is about 32 km beneath HSPB. Significant amplitudes on the transverse components of the RF indicate a shallowly dipping discontinuity (sedimentary-basement) towards the south-west. The fast polarization of SKS phases is near parallel to the border between the continental and the oceanic crust and the Hornsund fault (α = 151.8°). The average time delay dt between “fast” and “slow” directions is 0.68 s, which implies ca. 2% anisotropy in a 100- 200 km thick layer in the mantle.

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Authors and Affiliations

Monika Wilde-Piórko
Marek Grad
Paweł Wiejacz
Johannes Schweitzer
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Abstract

The work includes the results of numerical, analytical-numerical and experimental study into the influence of load eccentricities with regard to major axis on post-buckling behaviour and load-carrying capacity of thin-walled cold-formed steel lipped channel section columns. The study was solved by using the finite element method (code Ansys) with taking into consideration a full material characteristics in logarithmic strain system and geometric nonlinearities. The analytical-numerical solution was based on Koiter’s theory with an application of finite difference method (FDM). Some chosen results of numerical simulations have been compared to experimental results. The deformations of columns were registered by means of Digital Image Correlation Aramis System (DICAS) to observe the maps and the magnitude of displacements for adequate point of a load. The analyses showed that the decrease in maximum load in a dependency on the eccentricity value can be even 3 times minor in a comparison to the load-carrying capacity of axially loaded column.
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Authors and Affiliations

Leszek Czechowski
1
ORCID: ORCID
Maria Kotełko
1
ORCID: ORCID
Jacek Jankowski
1
ORCID: ORCID
Viorel Ungureanu
2
ORCID: ORCID
Annabella Sanduly
1
ORCID: ORCID

  1. Lodz University of Technology, Faculty of Mechanical Engineering, Stefanowskiego 1/15 street, 90-537 Lodz, Poland
  2. Department of Steel Structures and Structural Mechanics, Politehnica University of Timisoara, Romania
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Abstract

The paper presents two algorithms as a solution to the problem of identifying fraud intentions of a customer. Their purpose is to generate variables that contribute to fraud models’ predictive power improvement. In this article, a novel approach to the feature engineering, based on anomaly detection, is presented. As the choice of statistical model used in the research improves predictive capabilities of a solution to some extent, most of the attention should be paid to the choice of proper predictors. The main finding of the research is that model enrichment with additional predictors leads to the further improvement of predictive power and better interpretability of anti-fraud model. The paper is a contribution to the fraud prediction problem but the method presented may generate variable input to every tool equipped with variableselection algorithm. The cost is the increased complexity of the models obtained. The approach is illustrated on a dataset from one of the European banks.

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Authors and Affiliations

Damian Przekop
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Abstract

This paper presents the beam tracing with refraction method, developed to examine the possibility of creating the beam tracing simulation of sound propagation in environments with piecewise non- homogenous media. The beam tracing with refraction method (BTR) is developed as an adaptive beam tracing method that simulates not only the reflection but also the refraction of sound. The scattering and the diffraction of sound are not simulated. The BTR employs 2D and 3D topology in order to efficiently simulate scenes containing non-convex media. After the beam tracing is done all beams are stored in a beam tree and kept in the computer memory. The level of sound intensity at the beginning of each beam is also memorized. This beam data structure enables fast recalculation of results for stationary source and geometry. The BTR was compared with two commercial ray tracing simulations, to check the speed of BTR algorithms. This comparison demonstrated that the BTR has a performance similar to state-of- the-art room-acoustics simulations. To check the ability to simulate refraction, the BTR was compared with a commercial Finite Elements Method (FEM) simulation. In this comparison the BTR simulated the focusing of the ultrasound with an acoustic lens, with good accuracy and excellent performance.

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Authors and Affiliations

Marjan Sikora
Ivo Mateljan
Nikola Bogunović
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Abstract

Traditional fluid mechanics edifies the indifference between liquid and gas flows as long as certain similarity parameters – most prominently the Reynolds number – are matched. This may or may not be the case for flows in nano- or microdevices. The customary continuum, Navier-Stokes modelling is ordinarily applicable for both air and water flowing in macrodevices. Even for common fluids such as air or water, such modelling bound to fail at sufficiently small scales, but the onset for such failure is different for the two forms of matter. Moreover, when the no-slip, quasi-equilibrium Navier – Stokes system is no longer applicable, the alternative modelling schemes are different for gases and liquids. For dilute gases, statistical methods are applied and the Boltzmann equation is the cornerstone of such approaches. For liquid flows, the dense nature of the matter precludes the use of the kinetic theory of gases, and numerically intensive molecular dynamics simulations are the only alternative rooted in first principles. The present article discusses the above issues, emphasizing the differences between liquid and gas transport at the microscale and the physical phenomena unique to liquid flows in minute devices.

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Authors and Affiliations

M. Gad-El-Hak
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Abstract

Ecumenical Dimension of Theological Method

Summary

The article deals with the theme of the ecumenical dimension of theological method. Since the union of Christians should be based on looking for the fullness of Christian truth, each good theologian undertakes his work recognizing its ecumenical character. He is open to the Holy Spirit, the Bible, the voice of the Hierarchical Magisterium and the sense of the faithful. He wants to understand in a systematic and methodical way the common faith of all Christians. In consequence, to be a Christian theologian means to be ecumenical.

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Authors and Affiliations

Ks. Marek Skierkowski

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