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Abstract

Civil engineering is one of the many fields of occurrences of uncertain parameters. The present paper in an attempt to present and describe the most common methods used for inclusions of uncertain parameters . These methods can be applied in the area of civil engineering as well as for a larger domain. Definitions and short explanations of methods based on probability, interval analysis, fuzzy sets, and convex sets are presented. Selected advantages, disadvantages, and the most common fields of implementation are indicated.

An example of a cantilever beam presented in this paper shows the main differences between the methods. Results of the performed analysis indicate that the use of convex sets allows us to obtain an accuracy of results similar to stochastic models. At the same time, the computational speed characteristic for interval methods is maintained.

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Authors and Affiliations

J. Pełczyński
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Abstract

Measurements of the hardening process of the selected self-setting sands are presented in the hereby paper. Moulding sands were prepared

on the matrix of „Szczakowa” sand of the Sibelco Company. Two resins: phenol-formaldehyde-furfuryl (FF/AF) and urea-formaldehydefurfuryl

(MF/AF) were used for making moulding sands. – Methylbenzene-sulphonic acid was applied as a hardener for the moulding sand

on FF/AF resin, while paratoluene-sulphonic acid for the moulding sand on MF/AF resin. Both hardeners were used in two concentrations:

low – the so-called ‘slow’ hardener and high - ‘fast’ hardener. During investigations, the courses of the hardening process were

determined, more accurately changes of the velocity of the ultrasound wave passage through the moulding sand cL = f(t) and changes of

the moulding sand hardening degree versus time, Sx = f(t). In addition, the kinetics of the hardening process was determined.

Measurements were performed on the research stand for ultrasound investigations.

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Authors and Affiliations

Ł. Jamrozowicz
J. Kolczyk
N. Kaźnica
Z. Pyziak
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Abstract

The paper presents the idea of the integrated recycling system of used moulding sands with organic resins. A combination of the method of

forecasting averaged ignition loss values of moulding sands after casting and defining the range of necessary matrix reclamation

treatments in order to obtain its full recycling constitutes the basics of this process.

The results of own investigations, allowing to combine ignition loss values of spent moulding sands after casting knocking out with

amounts of dusts generated during the mechanical reclamation treatment of such sands, were utilized in the system.

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Authors and Affiliations

R. Dańko
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Abstract

Measurements of the hardening process course of the selected self-hardening moulding sands with the reclaimed material additions to the matrix, are presented in the hereby paper. Moulding sands were produced on the „Szczakowa” sand (of the Sibelco Company) as the matrix of the main fraction FG 0,40/0,32/0,20, while the reclaim was added to it in amounts of 20, 50 and 70%. Regeneration was performed with a horizontal mechanical regenerator capacity of 10 t/h. In addition, two moulding sands, one on the fresh sand matrix another on the reclaimed matrix, were prepared for comparison. Highly-fluid urea-furfuryl resin was used as a binder, while paratoluensulphonic acid as a hardener. During investigations the hardening process course was determined, it means the wave velocity change in time: cL = f(t). The hardening process kinetics was also assessed (dClx/dt = f(t)). Investigations were carried out on the research stand for ultrasound tests. In addition strength tests were performed.

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Authors and Affiliations

Ł. Jamrozowicz
J. Kolczyk
P. Wojtuń
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Abstract

Positively invariant sets play an important role in the theory and applications of dynamical systems. The stability in the sense of Lyapunov of the equilibrium x = 0 is equivalent to the existence of the ellipsoidal positively invariant sets. The constraints on the state and control vectors of dynamical systems can be formulated as polyhedral positively invariant sets in practical engineering problems. Numerical checking method of positive invariance of polyhedral sets is addressed in this paper. The validation of the positively invariant sets can be done by solving LPs which can be easily done numerically. It is illustrated by examples that our checking method is effective. Compared with the now existing algebraic methods, numerical checking method is an attractive method in that it’s easy to be implemented.

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Authors and Affiliations

H. Yang
Y. Hu
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Abstract

The article outlines how to use the convergence of collections to determine the position of a mobile device based on the WiFi radio signal strength with the use of fuzzy sets. The main aim is the development of the method for indoor position determination based on existing WiFi network infrastructure indoors. The approach is based on the WiFi radio infrastructure existing inside the buildings and requires operating mobile devices such as smartphones or tablets. An SQL database engine is also necessary as a widespread data interface. The SQL approach is not limited to the determination of the position but also to the creation of maps in which the system dening the position of the mobile device will operate. In addition, implementation issues are presented along with the distribution of the burden of performing calculations and the benets of such an approach for determining the location. The authors describe how to decompose the task of determining the position in a client-server architecture.

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Authors and Affiliations

Michał Socha
Wojciech Górka
Iwona Kostorz
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Abstract

Arrow and Debreu proved that, if in the mathematical model of the economy that they defined some conditions are satisfied, then there is a price system under which there is Walras equilibrium in this economy. We examine a procedure, defined on the basis of a continuous mapping, of transformation of production sets of the Arrow-Debreu economies in which at least one of the assumptions concerning the production sets is not satisfied. Finally, we get a class of ArrowDebreu economies in which, after modification, there is Walras equilibrium. The research methods are based on the analysis of the linear mappings in real vector space of finite dimension, and the results have the form of mathematical theorems.
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Authors and Affiliations

Agnieszka Lipieta
1
Maria Sadko
1

  1. Krakow University of Economics
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Abstract

The article presents the results of the second part of an eye-tracking study conducted on Polish secondary school students working with a textbook for learning English. 20 dyslexic and 20 non- dyslexic school students worked with two sets of materials that had different graphic layouts but the same content. Their eye movements were recorded. The analysed data show that the arrangement of the material and images on the textbook page influence both the way the students (especially dyslexic ones) work with the book and their results.

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Authors and Affiliations

Agnieszka Andrychowicz-Trojanowska
Sambor Grucza
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Abstract

Self – Levelling Underlayment (SLU) is one of the high-performance new materials used in the construction industry. Besides the strength, other characteristics of SLU such as workability, rapid drying, rapid hardening, shrinkage compensation, smooth nature, etc. are required depending on the application. The aim of this study is to evaluate the structuration with the time of SLU through some important characteristics such as the evolution of rheological properties, ettringite, and gibbsite phase development. To this purpose, a rheometer with rotation mode and oscillation mode was used to determine the yield stress, plastic viscosity, rheological dynamic modulus (storage modulus and loss modulus). The use of these techniques is considered to be a method for monitoring structuration development in cement materials. The result shows that during the hydration process, increased plastic viscosity, yield stress, and dynamic modulus of the SLU were identified from just 5 minutes after mixing until the setting period when the transition from a fluid state to a solid-state of SLU takes place. By using a rheometer in oscillation mode, the beginning of the transition process from the liquid-state to the solid-state of SLU was identified, this method is more precise when compared to traditional Vicat method.
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Authors and Affiliations

Lam Ngoc Nguen
1

  1. Hanoi University of Civil Engineering, Faculty of Building Materials, 55 Giai Phong Road, Hai Ba Trung District, Hanoi, Viet Nam
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Abstract

A group of old apartment houses with the age over 100 years (that is those carried out before the First World War) takes an important place in polish building resources. Technical maintenance of apartment houses, traditional methods erected, is nowadays and will be a valid problem in the nearest future. The results of the work refer to the general population, estimated for 600 objects, that is about 20% of municipal downtown apartment houses in Wrocław.

The purpose of the research was to identify an influence of widely considered maintenance of apartment houses on a degree and intensity of their elements’ deterioration. The goal of the work has been fulfilled by symptoms’ analysis of declining of inspected elements’ exploitation values, that is identification of mechanics of their defects arising.

The range of the work has required creation of original qualitative model of pinpointed defects and its transfer into quantitative one. It has made possible to analyse the reason - effect phenomena „defect - technical wear” relevant to the most important elements of Wroclaw downtown district’s apartment houses. The research procedure has been conducted in accordance of fuzzy sets theory which made possible to describe qualitative model of pinpointed defects and its transfer into a quantitative one.

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Authors and Affiliations

J. Konior
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Abstract

In this paper, we randomly select 75 sets data of calcium sulfate hemihydrate (CSH) content and initial setting time, and the traditional test method of CSH and analyses initial setting time was used by complexometric titration. So the close relationship between them was studied in depth, which classification fitting data to be analyzed by regression analysis. The result shows that this regression analysis method can accurately determine CSH content in modified industrial by-product gypsum. The determination method has the advantages of simplification and rapid operation. As well as, the XRF quantitative analytical method was used to test the CSH content, which verified the accuracy of regression analysis method. The results also show that this method has high accuracy, and can simplify the traditional experimental process. The method developed is easier and more convenient and has broad prospects in application.

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Authors and Affiliations

Bing Li
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Abstract

The problem of setting out in civil engineering applications has been addressed in the literature for a long time. However, technological development has provided researchers with an opportunity of having other procedures in line with modern techniques in surveying sciences. One of the most important procedures in erecting steel structures, bridges, and precast columns of a building is the accurate placement of the anchorage system in concrete. The traditional method for staking out anchor bolts relies on sight rails, string lines, and tape measure. The precision of this art depends not only on the accuracy of observed offset distances during layout operations but also on the centerline of the anchoring template itself. Nowadays, the process of designing structures is executed using software that can perform a digital plan in CAD environment, where the coordinates of each anchor bolt can be defined. This research presents an accurate approach of positioning anchor bolts based on the second problem in surveying and total station. Error analysis and field application are described to evaluate the performance of the proposed method. However, the results indicate that the developed technique increases productivity, reduces the cost, and improves the positional accuracy.

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Authors and Affiliations

M. Habib
A. Malkawi
M. Awwad
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Abstract

Works connected with execution of geodesic and photogrammetric surveys and with setting up maps in the scale of 1:5000 of environs of the Polish Polar Station on the Isbjörnhamna Bay and in the scale of 1:500 of the area covered with buildings of the Station are discussed.

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Authors and Affiliations

Stanisław Dąbrowski
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Abstract

For the reason of environmental problems connected with the use of furan binders, attention is increasingly being paid to self-setting mixtures using alkali resols. A resol binder stabilized with KOH, NaOH is hardened by liquid esters with the formation of alkaline salts. The increase of their concentration affects the shortening of the mixture bench life, it also decreases strength, increases abrasive wear to moulds and cores, and results in uneconomical dilution of the reclaim with expensive new base sand. The length of life (bench life) of mixtures plays an important role in the manufacture of huge and voluminous moulds and cores in self-setting mixtures. This study aims at analyzing the function of reactive alkaline salts in the reclaim, monitors the consequences of its thermal exposure on the properties of selfsetting mixtures, and deals with development of methods evaluating its qualities.

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Authors and Affiliations

P. Jelínek
J. Beňo
J. Duda
F. Mikšovský
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Abstract

Two formal types of models of living processes, especially evolutionary ones, may be distinguished: the well-known mathematical type and the less-known logical one. The latter applies the terms “class” or “set”; both the terms are understood either in a collective sense (in mereology) or in a distributive sense (in set theory). These formal terms may be used among others to such organic multiplicities as populations or species of organisms, and to organic constituents (molecules, cells, organs) of living organism. Collective concepts refer to objects existing in nature, whereas distributive concepts refer to the linguistic and research constructions of models of natural objects, developed to cognitively grasp natural regularities.

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Authors and Affiliations

Józef Andrzej Stuchliński
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Abstract

The paper is dedicated to the robustness analysis of scalar multi-agent dynamical systems. The open problem we aim to address is the one related to the impact of additive disturbances. Set-theoretic methods are used to achieve the main results in terms of positive invariance and admissible bounds on the disturbances.
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Authors and Affiliations

Katarzyna Topolewicz
1
Sorin Olaru
2
Ewa Girejko
1
Carlos E.T. Dórea
3

  1. Faculty of Computer Science, Bialystok University of Technology, Poland
  2. Laboratory of Signals and Systems Centrale-Supelec, University Paris-Saclay, France
  3. Department of Computer Engineering and Automation, Universidade Federal do Rio Grande do Norte, UFRN-CT-DCA, 59078-900 Natal, RN, Brazil
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Abstract

Overseas mining investment generally faces considerable risk due to a variety of complex risk factors. Therefore, indexes are often based on conditions of uncertainty and cannot be fully quantified. Guided by set pair analysis (SPA) theory, this study constructs a risk evaluation index system based on an analysis of the risk factors of overseas mining investment and determines the weights of factors using entropy weighting methods. In addition, this study constructs an identity-discrepancycontrary risk assessment model based on the 5-element connection number. Both the certainty and uncertainty of the various risks are treated uniformly in this model and it is possible to mathematically describe and quantitatively express complex system decisions to evaluate projects. Overseas mining investment risk and its changing trends are synthetically evaluated by calculating the adjacent connection number and analyzing the set pair potential. Using an actual overseas mining investment project as an example, the risk of overseas mining investment can be separated into five categories according to the risk field, and then the evaluation model is quantified and specific risk assessment results are obtained. Compared to the field investigation, the practicability and effectiveness of the evaluation method are illustrated. This new model combines static and dynamic factors and qualitative and quantitative information, which improves the reliability and accuracy of risk evaluation. Furthermore, this evaluation method can also be applied to other similar evaluations and has a certain scalability.

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Authors and Affiliations

Zhaoyang Ma
Guoqing Li
Nailian Hu
Di Liu
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Abstract

When patterns to be recognised are described by features of continuous type, discretisation becomes either an optional or necessary step in the initial data pre-processing stage. Characteristics of data, distribution of data points in the input space, can significantly influence the process of transformation from real-valued into nominal attributes, and the resulting performance of classification systems employing them. If data include several separate sets, their discretisation becomes more complex, as varying numbers of intervals and different ranges can be constructed for the same variables. The paper presents research on irregularities in data distribution, observed in the context of discretisation processes. Selected discretisation methods were used and their effect on the performance of decision algorithms, induced in classical rough set approach, was investigated. The studied input space was defined by measurable style-markers, which, exploited as characteristic features, facilitate treating a task of stylometric authorship attribution as classification
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Authors and Affiliations

Urszula Stańczyk
1
Beata Zielosko
2

  1. Silesian University of Technology, ul. Akademicka 2A, 44-100 Gliwice, Poland
  2. University of Silesia in Katowice, ul. Będzińska 39, 41-200 Sosnowiec, Poland
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Abstract

The paper presents the experience of using the ŁPrP, ŁPKO, ŁPSp, ŁPSpA i ŁPSp3R types of flattened supports for longwall entries in the conditions of the JSW S.A. Knurów-Szczygłowice coal mine. The article concentrates on the support solutions applied in the conditions of the mine and the results in terms of stability and usefulness of the structures of the supports. An analysis of the load bearing capacity and technological conditions has been conducted for various flattened supports solutions, with special consideration given to the ŁPSp and ŁPrPJ support sets. Comparing these two, the ŁPSp exhibits a load bearing capacity that is 21% higher while using 31% less steel mass. The experiment results allowed to determine that the ŁPSpA and ŁPSp3R support types are an advantageous solutions in case of longwall set-up rooms.

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Authors and Affiliations

Piotr Głuch
Grzegorz Michalik
Tomasz Śledź
Piotr Kleibert
Adam Ratajczak
Jarosław Sobik
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Abstract

Theoretical and experimental research indicates that radial loads have a significant influence on the value of belt-on-idler rolling resistances. Computational models discussed in literature use the notion of unit rolling resistance, i.e. rolling resistance per unit length of the idler. The total value of the rolling resistance of belt on a single idler is determined by integrating unit rolling resistance with respect to the length of the contact zone between the belt and the idler. This procedure requires the knowledge of normal load distribution along the contact zone between the belt and the idler. Loads acting on the idler set have been the object of both theoretical analyses and laboratory tests. Literature mentions several models which describe the distribution of normal loads along the contact zone between the belt and the idler set (Krause & Hettler, 1974; Lodewijks, 1996; Gładysiewicz, 2003; Jennings, 2014). Numerous experimental tests (Gładysiewicz & Kisielewski, 2017; Król, 2017; Król & Zombroń, 2012) demonstrated that the resultant normal loads acting on idlers are approximate to the loads calculated in theoretical models. If the resultant normal load is known, it is possible to assume the distribution of loads acting along the contact zone between the belt and the idler. This paper analyzes various hypothetical load distributions calculated for both the center idler roll and for the side idler roll. It also presents the results of calculations of belt rolling resistances for the analyzed distributions. In addition, it presents the results of calculations with allowance for load distribution along the generating line of the idler.

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Authors and Affiliations

Lech Gładysiewicz
Martyna Konieczna-Fuławka
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Abstract

The basis for a mineral deposit delimitation is a qualitative and quantitative assessment of deposit parameters, qualifying a deposit as an economically valuable object. A conventional approach to the mineral deposit recognition and a deposit detailed parameters qualification in the initial stages of development work in the KGHM were presented in the paper. The goals of such recognition were defined, which through a gradual detailed expansion, resulting from the information inflow, allows for the construction of a more complete decision-making model. The description of the deposit parameters proposed in the article in the context of fuzzy logic, enables a presentation of imprecise statements and data, which may be a complement to a traditional description. Selected non-adjustable and adjustable s-norm and t-norm operators were demonstrated. Operators effects were tested for selected ore quality parameters (copper content and deposit thickness) by constructing adequate membership functions. In a practical application, the use of chosen fuzzy logic operators is proposed for the assessment of the qualitative parameters of copper-silver ore in the exploitation blocks for one of the mines belonging to KGHM Polish Copper S.A. The considerations have been extended by including the possibility of using compensation operators.

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Authors and Affiliations

Mariusz Krzak
Paweł Panajew
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Abstract

The present paper consists of two parts. The first part presents theoretical foundations of Msplit, estimation with reference to the previous author's paper (Wiśniewski, 2009). This time, some probabilistic assumptions are described in detail. A new quantity called f-information is also introduced to formulate the split potential in more general way. The main aim of this part of the paper is to generalize the target function of Msplit estimation that is the basis for a new formulation of the optimization problem. Such problem itself as well as its solution are presented in this part of the paper. The second part of the paper presents some special case of Mspli, estimation called squared Mspli, estimation (also with reference to the mentioned above paper of the author). That part presents a new solution and development in the theory of this version of M,plit estimation and some numerical examples that show properties of the method and its application scope.
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Authors and Affiliations

Zbigniew Wiśniewski
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Abstract

This part of the paper presents particular case of Msplit estimation called a squared Msplit estimation whose target function is based on convex squared functions. One can find here theoretical foundations and algorithm of the squared Msplit estimation as well as some numerical examples.
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Authors and Affiliations

Zbigniew Wiśniewski

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