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Number of results: 77
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Abstract

Values define the directions of human activities and are related to people’s motivation to undertake specific activities and roles (Schwartz, 1994; Brown, 2002). Researchers and employers observe differences in motivation to work among representatives of different generations and genders (Twenge, Campbell, & Freeman, 2012; Gursoy & Karadag, 2013). In this research project, the authors asked what motivated contemporary employees, whether the intensity of their motives was different in different generations, what relationships there were between the dominant work motives and employees’ dominant values, and whether there were differences between women and men regarding work motives. To verify the hypotheses, they conducted a study with a sample of 307 professionally active people. They used their own Types of Work Motives Questionnaire designed for the purposes of the study and the Valued Living Questionnaire (VLQ; Wilson & Murrell, 2004). The obtained results indicate that younger employees choose the kind of work that gives them comfort and adequate pay. Regardless of age, however, social security support is the most important for all groups of respondents. For women, security and social security support are important at work. Moreover, the study has shown that there is a relationship between work values and work motives. For example people who appreciate values such as friendship and stability are motivated to work by good relationships and security, those who value recreation and stability are motivated by comfort and salary, those for whom respect and education are crucial are motivated by the possibility of development etc.

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Authors and Affiliations

Dorota Godlewska-Werner
Aleksandra Peplińska
Anna Maria Zawadzka
Piotr Połomski
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Abstract

In this paper a mathematical model enabling the analysis of the heat-flow phenomena occurring in the waterwalls of the combustion chambers of the boilers for supercritical parameters is proposed. It is a one-dimensional model with distributed parameters based on the solution of equations describing the conservation laws of mass, momentum, and energy. The purpose of the numerical calculations is to determine the distributions of the fluid enthalpy and the temperature of the waterwall pipes. This temperature should not exceed the calculation temperature for particular category of steel. The derived differential equations are solved using two methods: with the use of the implicit difference scheme, in which the mesh with regular nodes was applied, and using the Runge-Kutta method. The temperature distribution of the waterwall pipes is determined using the CFD. All thermophysical properties of the fluid and waterwall pipes are computed in real-time. The time-spatial heat transfer coefficient distribution is also computed in the on-line mode. The heat calculations for the combustion chamber are carried out with the use of the zone method, thus the thermal load distribution of the waterwalls is known. The time needed for the computations is of great importance when taking into consideration calculations carried out in the on-line mode. A correctly solved one-dimensional model ensures the appropriately short computational time.

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Authors and Affiliations

Wiesław Zima
Sławomir Grądziel
Artur Cebula
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Abstract

Evaluation of moisture absorption in foodstuffs such as black chickpea is an important stage for skinning and cropping practices. Water uptake process of black chickpea was discussed through normal soaking in four temperature levels of 20, 35, 50 and 65 °C for 18 hours, and then the hydration kinetics was predicted by Peleg’s model and finite difference strategy. Model results showed that with increasing soaking temperature from 20 to 65 °C, Peleg’s rate and Peleg’s capacity constant reduced from 13.368×10-2 to 5.664×10-2 and 9.231×10-3 to 9.138×10-3, respectively. Based on key results, a rise in the medium temperature caused an increase in the diffusion coefficient from 5.24×10-10 m2/s to 4.36×10-9 m2/s, as well. Modelling of moisture absorption of black chickpea was also performed employing finite difference strategy. Comparing the experimental results with those obtained from the analytical solution of the theoretical models revealed a good agreement between predicted and experimental data. Peleg’s model and finite difference technique revealed their predictive function the best at the temperature of 65 °C.

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Authors and Affiliations

Nesa Dibagar
Stefan Jan Kowalski
Reza Amiri Chayjan
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Abstract

This paper presents the design, fabrication and testing of an improved thin-film thermal converter based on an electro-thermally excited and piezo-resistively detected micro-bridge resonator. The resonant thermal converter comprises a bifilar heater and an opposing micro-bridge resonator. When the micro-bridge resonator absorbs the radiant heat from the heater, its axial strain changes, then its resonant frequency follows. Therefore the alternating voltage or current can be transferred to the equivalent DC quantity. A non-contact temperature sensing mechanism eliminates heat loss from thermopiles and reduces coupling capacitance between the temperature sensor and the heater compared with traditional thin-film thermal converters based on thermopiles. In addition, the quasi-digital output of the resonant thin-film thermal converter eliminates such problems as intensity fluctuations associated with analogue signals output by traditional thin-film thermal converters. Using the fast-reversed DC (FRDC) method, the thermoelectric transfer difference, which determines the frequency-independent part of the ac-dc transfer difference, is evaluated to be as low as 1.1 · 10−6. It indicates that the non-contact temperature sensing mechanism is a feasible method to develop a high-performance thermal converter.

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Authors and Affiliations

Lizhen Dong
Jianqiang Han
Peng Zhang
Zhengqian Zhao
Bing Cheng
Dong Han
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Abstract

In this work studies of barrier height local values are presented. Distribution of the gate-oxide EBG(x, y) and semiconductor-oxide EBS(x, y) barrier height local values have been determined using the photoelectric measurement methods. Two methods were used to obtain the local values of the barrier heights: modified Powell-Berglund method and modified Fowler method. Both methods were modified in such a way as to allow determination of the EBG(x, y) and EBS(x, y) distribution over the gate area using a focused UV light beam of a small diameter d = 0.3 mm. Measurements have been made on a series of Al-SiO2-Si(n+) MOS structures with semitransparent (tAl = 35 nm) square aluminum gate (1 x 1 mm2). It has been found that the EBG(x, y) distribution has a characteristic dome-like shape, with highest values at the center of the gate, lower at the gate edges and still lower at gate corners. On the contrary, the EBS(x, y) distribution is of a random character. Also, in this paper, both barrier height measurements have been compared with the photoelectric effective contact potential difference fMS(x, y) measurements. These results show good agreement between distribution of the barrier heights EBG(x, y) and EBS(x, y) measurements and independently determined shape of the effective contact potential difference fMS(x, y) distribution.

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Authors and Affiliations

K. Piskorski
H.M. Przewlocki
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Abstract

In this paper, we establish variation of constant formulas for both Caputo and Riemann- Liouville fractional difference equations. The main technique is the Z -transform. As an application, we prove a lower bound on the separation between two different solutions of a class of nonlinear scalar fractional difference equations.

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Authors and Affiliations

Pham The Anh
Artur Babiarz
Adam Czornik
Michał Niezabitowski
ORCID: ORCID
Stefan Siegmund
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Abstract

We investigate a scalar characteristic exponential polynomial with complex coefficients associated with a first order scalar differential-difference equation. Our analysis provides necessary and sufficient conditions for allocation of the roots in the complex open left half-plane what guarantees asymptotic stability of the differential-difference equation. The conditions are expressed explicitly in terms of complex coefficients of the characteristic exponential polynomial, what makes them easy to use in applications. We show examples including those for retarded PDEs in an abstract formulation.
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Authors and Affiliations

Rafał Kapica
1
ORCID: ORCID
Radosław Zawiski
2
ORCID: ORCID

  1. Faculty of Applied Mathematics, AGH University of Science and Technology, al.Mickiewicza 30, 30-059 Kraków
  2. Department of Automatic Control and Robotics, Silesian University of Technology, ul. Akademicka 16, 44-100 Gliwice
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Abstract

We define the need for sense-making as the desire to find reliable connections between the objects, situations, and relationships that people encounter. We have proposed and tested that there are possible individual differences in the need for sense-making and that these individual differences are insightful in characterizing individuals and their behaviors. A correlational study (N = 229) showed that need for sense-making was positively related to self-esteem, extroversion, conscientiousness, openness, and sense of control. Additionally, a higher need for sense-making was associated with greater perception of it as an important part of people’s identity. Thus, need for sense-making is relevant to understanding individual differences and can furthermore comprise a significant element of people’s identity. These results break new ground in the study of individual differences in the need for sense-making and can be of great importance in work and organizational psychology.

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Authors and Affiliations

Katarzyna Cantarero
Wijnand A.P. van Tilburg
Beata Kuźma
Agata Gąsiorowska
Bogdan Wojciszke
ORCID: ORCID
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Abstract

Each European Union Member State keeps a register of data on properties located in its territory. The number, type and scope of these properties are determined by each Member State’s needs. The INSPIRE Directive enables the scope of data to be harmonised, and the data to be made available for the purpose of assisting legislators in taking decisions and actions likely to have either direct or indirect impact on the environment. The aim of the study was to indicate the basic differences between the data contained in Polish and Latvian cadastres. Unlike other similar studies analysing the content of data in the cadastre, this article pays special attention to the number of available sets of data about the parcel and its surroundings, the ease of access to these data and the possibility for acquiring them by an interested party without incurring additional fees. This is particularly important in activities related to spatial management and the development of an information society. The results show that in both countries, the decision makers have approached the INSPIRE Directive differently. Direct analyses conducted for the cities of Wrocław (Poland) and Riga (Latvia) demonstrated that the information system in Wrocław contains a considerably greater scope of information available free of charge, is easier to use and offers more services. The Latvian Republic’s spatial information system provides a less-developed scope of information about real estate (without fees) that is dispersed on several websites, which slows down and hinders its use.

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Authors and Affiliations

Katarzyna Kocur-Bera
Velta Parsova
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Abstract

In this work the effectiveness of the biotransformation of phosphogypsum in the cultures of sulphatereducing bacteria (SRB) was studied. SRB were isolated from soil contaminated with automobile fuel. The microorganisms were grown by two methods: the enrichment of the cultures and microcosms in: Postgate, minimal medium (with phenol, acetate or lactate) and Emerson medium. All media contained phosphogypsum as electron acceptors. The isolated microorganisms were passage in medium containing different carbon compounds: ethanol, lactate, phenol, acetate casein or lactose to test the effectiveness of biotransformation of phosphogypsum depending on the source of carbon used. In cultures in Postgate medium with lactate or casein there were found the maximal H2S concentration (654 and 540 mg HS-/dm3) and maximal decrease of phosphogypsum 84% and 64%, respectively. The isolated microorganisms utilised alcohol, sugar, protein and phenol.
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Authors and Affiliations

Dorota Wolicka
Włodzimierz Kowalski
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Abstract

Currently, the Republic of Kazakhstan is developing a new standard for symmetric data encryption. One of the candidates for the role of the standard is the Qamal encryption algorithm developed by the Institute of Information and Computer Technologies (Almaty, Republic of Kazakhstan). The article describes the algorithm. Differential properties of the main operations that make up the Qamal cypher are considered in the questions of stability. We have shown that for a version with a 128-bit data block and the same secret key size for three rounds of encryption it is difficult to find the right pairs of texts with a probability of 2–120, which makes differential cryptanalysis not applicable to the Qamal cypher.

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Authors and Affiliations

Kunbolat T. Algazy
Ludmila K. Babenko
Rustem G. Biyashev
Evgeniya A. Ishchukova
Ryszard Romaniuk
Nursulu A. Kapalova
Saule E. Nysynbaeva
Andrzej Smolarz
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Abstract

This study examined the relationship between gender role conflict and attitude towards psychological help-seeking. This study involved 120 university students from a university. Gender Role Conflict Scale was used to measure gender role conflict and Attitude towards Seeking Professional Psychological Help Scale-Short Form was used to measure attitude towards psychological help-seeking. The results found there is a significant negative relationship between gender role conflict and attitude towards seeking psychological help. The results suggest that it is essential for mental health professionals to recognise the impact of gender roles on the counselling process.

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Authors and Affiliations

Nirooj Loganathan
Fatt Mee Foo
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Abstract

This paper presents novel discrete differential operators for periodic functions of one- and two-variables, which relate the values of the derivatives to the values of the function itself for a set of arbitrarily chosen points over the function’s area. It is very characteristic, that the values of the derivatives at each point depend on the function values at all points in that area. Such operators allow one to easily create finite-difference equations for boundaryvalue problems. The operators are addressed especially to nonlinear differential equations.
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Bibliography

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[2] Burden R.L., Faires J.D., Numerical analysis, PWS-Kent Pub. Comp., Boston (1985).
[3] Taflove A., Computational electrodynamics: the finite-difference time-domain method, Artech House, Boston – London (1995).
[4] Strikwerda J.C., Finite Difference Schemes and Partial Differential Equations, Society for Industrial and Applied Mathematics, Second Edition, Philadelphia (2004).
[5] LeVeque R.J., Finite difference methods for ordinary and partial differential equations, Society for Industrial and Applied Mathematics, Second Edition, Philadelphia (2007).
[6] Fortuna Z., Macukow B., Wasowski J., Numerical methods, WNT (in Polish), Warsaw (2009).
[7] Esfandiari R.S., Numerical Methods for Engineers and Scientists Using MATLABr, CRC Press, Taylor & Francis Group (2017).
[8] Zakrzewski K., Łukaniszyn M., Application of 3-D finite difference method for inductance calculation of air-core coils system, COMPEL International Journal of Computations and Mathematics in Electrical Engineering, vol. 13, no. 1, pp. 89–92 (1994).
[9] Demenko A., Sykulski J., On the equivalence of finite difference and edge element formulations in magnetic field analysis using vector potential, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33, no. 1/2, pp. 47–55 (2014).
[10] Huang J., LiaoW., Li Z., A multi-block finite difference method for seismic wave equation in auxiliary coordinate system with irregular fluid–solid interface, Engineering Computations, vol. 35, no. 1, pp. 334–362 (2018).
[11] Chapwanya M., Dozva R., Gift Muchatibaya G., A nonstandard finite difference technique for singular Lane-Emden type equations, Engineering Computations, vol. 36, no. 5, pp. 1566–1578 (2019).
[12] Mawlood M., Basri S., AsrarW., Omar A., Mokhtar A., Ahmad M., Solution of Navier-Stokes equations by fourth-order compact schemes and AUSM flux splitting, International Journal of Numerical Methods for Heat and Fluid Flow, vol. 16, no. 1, pp. 107–120 (2006).
[13] Ivanovic M., Svicevic M., Savovic S., Numerical solution of Stefan problem with variable space grid method based on mixed finite element/finite difference approach, International Journal of Numerical Methods for Heat and Fluid Flow, vol. 27, no. 12, pp. 2682–2695 (2017).
[14] Sobczyk T.J., Algorithm for determining two-periodic steady-states in AC machines directly in time domain, Archives of Electrical Engineering, Polish Academy of Science, Electrical Engineering Committee, vol. 65, no. 3, pp. 575–583 (2016), DOI: 10.1515/aee-2016-0041.
[15] Sobczyk T.J., Radzik M., Radwan-Pragłowska N., Discrete differential operators for periodic and two-periodic time functions, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 38, no. 1, pp. 325–347 (2019).
[16] Sobczyk T.J., Radzik M., A new approach to steady state analysis of nonlinear electrical circuits, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 37, no. 3, pp. 716–728 (2017).
[17] Sobczyk T.J., Radzik M., Tulicki J., Direct steady-state solutions for circuit models of nonlinear electromagnetic devices, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 40, no. 3, pp. 660–675 (2021), DOI: 10.1108/COMPEL-10-2020-0324.
[18] Sobczyk T.J., Jaraczewski M., Application of discrete differential operators of periodic functions to solve 1D boundary-value problems, COMPEL – The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Emerald Pub. Ltd., vol. 39, no. 4, pp. 885–897 (2020).
[19] Sobczyk T.J., 2D discrete operators for periodic functions, Proceedings IEEE Conference Selected Issues of Electrical Engineering and Electronics (WZZE), Zakopane, Poland, pp. 1–5 (2019), https://ieeexplore.ieee.org/document/8979992.
[20] Jaraczewski M., Sobczyk T., Leakage Inductances of Transformers at Arbitrarily Located Windings, Energies, vol. 13, no. 23, 6464 (2020), DOI: 10.3390/en13236464.

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Authors and Affiliations

Tadeusz Jan Sobczyk
1
ORCID: ORCID

  1. Department of Electrical Engineering, Faculty of Electrical and Computer Engineering, Cracow University of Technology, 24 Warszawska str., 31-155 Kraków, Poland
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Abstract

This paper presents the concept of using algorithms for reducing the dimensions of finite-difference equations of two-dimensional (2D) problems, for second-order partial differential equations. Solutions are predicted as two-variable functions over the rectangular domain, which are periodic with respect to each variable and which repeat outside the domain. Novel finite-difference operators, of both the first and second orders, are developed for such functions. These operators relate the value of derivatives at each point to the values of the function at all points distributed uniformly over the function domain. A specific feature of the novel operators follows from the arrangement of the function values as well as the values of derivatives, which are rectangular matrices instead of vectors. This significantly reduces the dimensions of the finite-difference operators to the numbers of points in each direction of the 2D area. The finite-difference equations are created exemplary elliptic equations. An original iterative algorithm is proposed for reducing the process of solving finite-difference equations to the multiplication of matrices.

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Authors and Affiliations

T. Sobczyk
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Abstract

The same speech sounds (phones) produced by different speakers can sometimes exhibit significant differences. Therefore, it is essential to use algorithms compensating these differences in ASR systems. Speaker clustering is an attractive solution to the compensation problem, as it does not require long utterances or high computational effort at the recognition stage. The report proposes a clustering method based solely on adaptation of UBM model weights. This solution has turned out to be effective even when using a very short utterance. The obtained improvement of frame recognition quality measured by means of frame error rate is over 5%. It is noteworthy that this improvement concerns all vowels, even though the clustering discussed in this report was based only on the phoneme a. This indicates a strong correlation between the articulation of different vowels, which is probably related to the size of the vocal tract.
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Authors and Affiliations

Robert Hossa
Ryszard Makowski
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Abstract

The study presents the analysis of the effects occurring at the propagation of electromagnetic waves within an area containing non-ideal, non-homogenous and absorbing dielectric. The analysed models are connected with housing constructions and include single and double-layered walls made of clay hollow bricks. The influence of the size of holes, the contained clay mass percentage and conductivity of brick on the distribution of electric field is presented. Double-layered wall causes more heterogeneity in distribution of electric field and numerous maxima and minima to compare with singlelayered construction. The presented results refer to the electromagnetic field generated by a wireless communication system (Wi-Fi), operating within the standard frequencies (2.4 GHz and 5 GHz). A FDTD method was used to the analysis of electric field distribution. Also in this paper all formulations of difference method (FDTD) is presented. The possibilities of modifying the described method are indicated too. The obtained values of electric field intensity allow to determining the attenuation coefficient for different variants of the walls. Detailed analysis of influence of different types of building construction will make it possible to better understand the wave phenomena and counteract local fading at planning of wireless networks systems.

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Authors and Affiliations

Agnieszka Choroszucho
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Abstract

Determination of the phase difference between two sinusoidal signals with noise components using samples of these signals is of interest in many measurement systems. The samples of signals are processed by one of many algorithms, such as 7PSF, UQDE and MSAL, to determine the phase difference. The phase difference result must be accompanied with estimation of the measurement uncertainty. The following issues are covered in this paper: the MSAL algorithm background, the ways of treating the bias influence on the phase difference result, comparison of results obtained by applying MSAL and the other mentioned algorithms to the same real signal samples, and evaluation of the uncertainty of the phase difference.

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Authors and Affiliations

Lazar V. Saranovac
Nada M. Vučijak
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Abstract

We present an alternative method to detect and measure the concentration changes in liquid solutions. The method uses Digital Holographic Interferometry (DHI) and is based on measuring refractive index variations. The first hologram is recorded when a wavefront from light comes across an ordinary cylindrical glass container filled with a liquid solution. The second hologram is recorded after slight changing the liquid’s concentration. Differences in phase obtained from the correlation of the first hologram with the second one provide information about the refractive index variation, which is directly related to the changes in physical properties related to the concentration. The method can be used − with high sensitivity, accuracy, and speed − either to detect adulterations or to measure a slight change of concentration in the order of 0.001 moles which is equivalent to a difference of 0.003 g of sodium chloride in solutions. The method also enables to measure and calculate the phase difference among each pixel of two samples. This makes it possible to generate a global measurement of the phase difference of the entire sensed region.

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Authors and Affiliations

Carlos Guerrero-Méndez
Tonatiuh Saucedo-Anaya
Maria Araiza-Esquivel
Raúl E. Balderas-Navarro
Alfonso López-Martínez
Carlos Olvera-Olvera
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Abstract

In this article we construct a finite-difference scheme for the three-dimensional equations of the atmospheric boundary layer. The solvability of the mathematical model is proved and quality properties of the solutions are studied. A priori estimates are derived for the solution of the differential equations. The mathematical questions of the difference schemes for the equations of the atmospheric boundary layer are studied. Nonlinear terms are approximated such that the integral term of the identity vanishes when it is scalar multiplied. This property of the difference scheme is formulated as a lemma. Main a priori estimates for the solution of the difference problem are derived. Approximation properties are investigated and the theorem of convergence of the difference solution to the solution of the differential problem is proved.
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Authors and Affiliations

Almas N. Temirbekov
Urmashev Baydaulet A.
Konrad Gromaszek
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Abstract

This paper compares numerical solutions of transient two-dimensional unsaturated flow equation by using different averaging schemes for internodal conductivities. Averaging methods such as arithmetic mean, geometric mean, upstream weighting, and integrated mean are taken into account, as well as a recent approach based on steady-state approximation. The latter method proved the most flexible, producing relatively accurate solutions for both downward and upward flow cases.

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Authors and Affiliations

A. Szymkiewicz
K. Burzyński
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Abstract

The paper presents the dynamic behaviour of three-layer annular plates with damaged facings. The plate is composed of thin laminated, fibre-reinforced composite facings and thicker, foam core. Failure of the plate facings is modelled as fibre or matrix cracks. The plate loaded in the plane of facings with quickly increasing radially compressed forces loses its dynamic stability. Evaluation of the critical state of the plate with failures was carried out using both analytical and numerical solutions. The comparison of results between plates with material properties treated as isotropic, quasi-isotropic and composite has been conducted. Presented tables and figures create the image of dynamic responses of examined composite plates with structure failures.

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Authors and Affiliations

Dorota Pawlus

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