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Number of results: 129
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Abstract

The purpose of this paper is to compare two approaches applied in property valuation: artificial neural networks and spatial regression. Despite the fact that artificial neural networks are often the first choice for modeling in the big data era, spatial econometrics methods offer incorporation of information on dependences between multiple objects in the studied space. Although this dependency structure can be incorporated into artificial neural network via feature engineering, this study is focused on abilities of reproducing it with machine learning method from crude coordinate data. The research is based on the database of 18,166 property sale transactions in Warsaw, Poland. According to this study, such volume of data does not allow artificial neural networks to compete in reflecting spatial dependence structure with spatial regression models.
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Authors and Affiliations

Damian Przekop
1

  1. Warsaw School of Economics, Poland
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Abstract

On the basis of corpus-derived data, the present paper examines the collocational patterns of the singular and the plural forms of a pair of etymologically and semantically related quantifying nouns (QNs), namely English heap and its Polish equivalent kupa ‘heap’. The primary aim is to determine their respective levels of numeralization, operationalized as the frequency of co-occurrence with animate and abstract N2-collocates in purely quantificational uses, in an attempt to establish whether, and to what extent, the addition of the plurality morpheme bears on the grammaticalization of a nominal of this kind into an indefinite quantifier. Following the observations arrived at by Brems (2003, 2011), the hypothesis is that pluralization should yield a facilitating effect on the numeralization of nouns referring to large quantities by amplifying their inherent scalar implications. The results demonstrate that whereas heaps indeed exhibits a higher percentage of such numeralized uses than heap, kupy ‘heaps’ has turned out to be grammaticalized in the quantifying function to a markedly lesser degree than kupa ‘heap’. It is argued that this apparently aberrant behaviour of kupy ‘heaps’ can nonetheless be elucidated in terms of the specificity of numeralization in Polish, since at its advanced, morphosyntactic stage, the process in question affects solely the singular (accusative) forms of QNs.

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Authors and Affiliations

Damian Herda
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Abstract

The paper presents the results of field studies carried out in I O chosen forest islands in a suburban area of the town of Jaworzno in the years 1995-2002. Different objects have been studied, among others: natural remnants of oak-hornbeam forest and planted pine-larch woodlots cultivated on the habitat of xerothermic grasslands. In comparison with the total nora of the town, the participation of non-synantropie species and synecological groups associated with natural habitats is much bigger. There are 24 protected species to be found, 40% of protected nora of the town. Despite their diversity, they are precious refugees of many woodland and grassland as well as meadow species occurring within the areas and in their vicinity.
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Authors and Affiliations

Damian Chmura
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Abstract

The article reviews the results of experimental tests assessing the impact of process parameters of additive manufacturing technologies on the geometric structure of free-form surfaces. The tests covered surfaces manufactured with the Selective Laser Melting additive technology, using titanium-powder-based material (Ti6Al4V) and Selective Laser Sintering from polyamide PA2200. The evaluation of the resulting surfaces was conducted employing modern multiscale analysis, i.e., wavelet transformation. Comparative studies using selected forms of the mother wavelet enabled determining the character of irregularities, size of morphological features and the indications of manufacturing process errors. The tests provide guidelines and allow to better understand the potential in manufacturing elements with complex, irregular shapes.
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Authors and Affiliations

Damian Gogolewski
1

  1. Kielce University of Technology, Department of Mechanical Engineering and Metrology, al. Tysiaclecia Panstwa Polskiego 7, 25-314 Kielce, Poland
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Abstract

The aim of the article is to reconstruct the cardinal theses and assumptions of the materialistic-dialectical ontology in the post-Stalinist Marxist scientific philosophy, often described as "Eastern Marxism". Basing on the source literature covering the works of the most eminent Polish (Stefan Amsterdamski, Stanisław Butryn, Helena Eilstein, Władysław Krajewski, Jan Such, Wiesław Sztumski and others) and Soviet (Fedosseyev, Konstantinov, Szeptulin, Rubinshtajn, etc.) philosophers which studied the links between dialectical materialism and natural sciences, I claim that postwar Marxist scientism clarifies the concise intuitions of the classics of Marxism regarding the nature and assumptions of dialectical materialism, especially the dialectic of nature. Contrary to the current interpretations of the sources of dogmatism in Marxism as the dominant ontological assumption of dialectical and natural materialism, according to these findings, it turns out that after its post-war modernization, the dialectical ontology was cleared of numerous dogmas and misunderstandings. Moreover, it turns out to be consistent with the general assumptions of the anti-Stalinist Marxist social and political philosophy.
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Authors and Affiliations

Damian Winczewski
1

  1. UMCS, Instytut Filozofii, Pl. M. Skłodowskiej-Curie 4, Lublin
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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

In this paper, an algorithm will be presented that enables solving the two-phase inverse Stefan problem, where the additional information consists of temperature measurements in selected points of the solid phase. The problem consists in the reconstruction of the function describing the heat transfer coefficient, so that the temperature in the given points of the solid phase would differ as little as possible from the predefined values. The featured examples of calculations show a very good approximation of the exact solution and stability of the algorithm.

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Authors and Affiliations

Damian Słota
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Abstract

The paper presents a methodology for parametric fault clustering in analog electronic circuits with the use of a self-organizing artificial neural network. The method proposed here allows fast and efficient circuit diagnosis on the basis of time and/or frequency response which may lead to higher production yield. A self-organizing map (SOM) has been applied in order to cluster all circuit states into possible separate groups. So, it works as a feature selector and classifier. SOM can be fed by raw data (data comes from the time or frequency response) or some pre-processing is done at first. The author proposes conversion of a circuit response with the use of e.g. gradient and differentiation. The main goal of the SOM is to distribute all single faults on a two-dimensional map without state overlapping. The method is aimed for the development stage because the tolerances of elements are not taken into account, however single but parametric faults are considered. Efficiency analyses of fault clustering have been made on several examples e.g. a Sallen-Key BPF and an ECG amplifier. Testing procedure is performed in time and frequency domains for the Sallen-Key BPF with limited number of test points i.e. it is assumed that only input and output pins are available. A similar procedure has been applied to a real ECG amplifier in the frequency domain. Results prove a high efficiency in acceptable time which makes the method very convenient (easy and quick) as a first test in the development stage.

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Authors and Affiliations

Damian Grzechca
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Abstract

This paper presents an experimental study on influence of input light polarization on the spectral characteristics of a fibre twist sensor based on Tilted Fiber Bragg Grating (TFBG) with simultaneous application of bending to an optical fibre. The application of proposed measurement stand could provide the ability of transforming the bending to a displacement. The twist measurement was performed by tuning of the sensor illuminating light polarization angle. The spectral parameters of selected cladding mode which are sensitive to the rotation of input light polarization angle have been shown. This paper shows the characteristics of transmittivity and wavelength shift for an incident high-order cladding mode measured with different curvatures of fibre. The dependency of selected cladding mode spectral parameters related with the twist measurement on the influence of temporary bending has been shown. The measurements were performed for two positions of sensing structure refractive index perturbations in relation to the bending direction plane. The experimental results show that the direction of TFBG structure bending has a small influence on the stability of spectral parameters characteristic for twist measurement, assuming that the bending direction is fixed while measurement.

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Authors and Affiliations

Damian Harasim
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Abstract

The paper presents results of the localization of main noise sources in the industrial plant. Identification of main noise sources was made with an acoustic camera using Beamforming Method. Parallel to the measurements by means of the acoustic camera, sound level measurements on the main noise sources have been performed. Based on the calculations, prediction regarding the noise emission at residential buildings located near to the plant has been determined. Acoustic noise maps have been performed with LEQ Professional software, which includes the 3D geometry of the buildings inside the plant. It has been established that, after introduction of noise reduction measures in the plant, the noise levels at the observation points in the residential area meets the limit values.

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Authors and Affiliations

Wiesław Fiebig
Damian Dąbrowski
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Abstract

Fallow wasteland, seemingly worthless for agriculture, may in fact be of great natural value. We need to be very cautious when using it for cultivating energy plants.
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Authors and Affiliations

Wojciech Solarz
Damian Chmura
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Abstract

This paper presents exemplary exercise on the fundamentals of signal processing course which is offered for second year bachelor level students. Application of Field Programmable Analog Array (FPAA) for pulse amplitude modulation (PAM) exercise is described with signal processing laboratory. There are presented two methods for implementing PAM modulation and demodulation technique in FPAA module. Example configuration files are available form Authors’ web site.

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Authors and Affiliations

Damian Grzechca
Lukas Chruszczyk
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Abstract

The article shows the possibility of using TFBG gratings to measure the radius of curvature of fiber bending in conditions of variable polarization of the introduced light. Most of the modern, stable light sources generate light with a high degree of polarization. Due to the spatial asymmetry, the direction of the light polarization plane affects the spectral parameters of individual modes. For this reason, in the measurement systems using TFBGs presented so far it becomes necessary to determine and control the state of light polarization directly in front of the periodic structure. The article presents the determined spectral parameters of the cladding modes which allow bending measurements regardless of the direction of polarization of the introduced light. Thanks to this, the measuring system can be constructed without providing control of the introduced light polarization angle, which makes its construction simpler. When using TFBGs with an angle of 2°, the accuracy of determining the bending radius in the range from 15 mm to 30 mm when changing the angle of the plane of polarization in the full range is 0.318 mm in the case of changes in the transmission coefficient. For changes in the wavelength of the selected cladding mode, the accuracy is 0.3203 mm, with the input light polarization being changed in the range from 0° (P type) to 90° (S type).
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Authors and Affiliations

Damian Harasim
1
Sławomir Cięszczyk
1

  1. Lublin University of Technology, Electrical and Information Technology Department, Nadbystrzycka Str. 36D, Lublin, Poland
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Abstract

In this paper, impact of changes in parameters of offered traffic on the accuracy of determining the parameters of overflow traffic in hierarchical systems with multi-service traffic was presented. Pascal type traffic streams were offered to the considered systems. The study investigated the impact of changes in the number of sources, intensity of traffic offered by individual classes, as well as changes in the traffic offered by a single free source. The presented results are based on determined relative errors of the values of overflow traffic obtained in simulations and on the basis of calculations.

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Authors and Affiliations

Marian Głąbowski
Damian Kmiecik
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Abstract

The paper presents results of experimental tests carried out on concrete beams reinforced with glass fibre polymer reinforced (GFRP) bars, which have become recently one of the main substitutes for traditional steel reinforcement. GFRP bars were used in this research as the longitudinal and transverse reinforcement. An objective of the study was to investigate the influence of the shear reinforcement ratio on the shear capacity of GFRP reinforced concrete beams in comparison with the corresponding beam without shear reinforcement. Single-span, simply-supported T-section beams reinforced in flexure with 5 GFRP bars of 25 mm diameter were reinforced in shear with closed GFRP stirrups of 8 mm diameter applied in three variable spacings: 250 mm, 200 mm and 120 mm. The analysis of test results, failure modes and shear capacity is discussed in the paper in respect to investigated parameters.
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Authors and Affiliations

Damian Szczech
1
Renata Kotynia
1

  1. Lodz University of Technology, Faculty of Civil Engineering, Architecture and Environmental Engineering, al. Politechniki 6, 90-924 Łódź, Poland
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Abstract

A lot of interest has recently been put into the so-called ‘virtual cryptographic currencies’, commonly known as cryptocurrencies, along with its surrounding market. The blockchain technology that stands behind them is also becoming increasingly popular. From the perspective of maintaining energy security, an important issue is the process of mining individual cryptocurrencies, which is associated with very high energy consumption. This operation is usually related to the approval of new blocks in the blockchain network and attaching them to the chain. This process is carried out through performing complex mathematical operations by various devices, which in turn require high power and respectively consume a lot of energy. The impact of cryptocurrency miners on the power and energy demand level might gradually increase over time, therefore this issue shouldn’t be ignored. Comparing the above information in parallel with the growing need for providing demand side response (DSR) services in the Polish Power System, raises the question whether devices used for mining cryptocurrencies can be used for the purpose of balancing the power system. This paper presents an analysis of the possibility to provide the demand side response services by groups of cryptocurrency miners users. The analysis was carried out taking basic functional, technological and economical aspects of these devices’ operations into account.

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Authors and Affiliations

Damian Mrowiec
Piotr Saługa

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