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Recent items
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On DoA estimation for rotating arrays using stochastic maximum likelihood approach
- Michał Meller
- Kamil Stawiarski
The flexibility needed to construct DoA estimators that can be used with rotating arrays subject to rapid variations of the signal frequency is offered by the stochastic maximum likelihood approach. Using a combination of analytic methods and Monte Carlo simulations, we show that for low and moderate source correlations the stochastic maximum likelihood estimator that assumes noncorrelated sources has accuracy comparable to the estimator that includes the correlation coefficient as one of the parameters. We propose several fast approximations of the stochastic maximum likelihood estimator and compare their accuracy with the Cramer-Rao lower bound. We also discuss the model order selection problem for the binary- and multiple-hypotheses cases.
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On Dynamic Extension of a Local Material Symmetry Group for Micropolar Media
- Victor Eremeev
- Violetta Konopińska-Zmysłowska
For micropolar media we present a new definition of the local material symmetry group considering invariant properties of the both kinetic energy and strain energy density under changes of a reference placement. Unlike simple (Cauchy) materials, micropolar media can be characterized through two kinematically independent fields, that are translation vector and orthogonal microrotation tensor. In other words, in micropolar continua we have six degrees of freedom (DOF) that are three DOFs for translations and three DOFs for rotations. So the corresponding kinetic energy density nontrivially depends on linear and angular velocity. Here we define the local material symmetry group as a set of ordered triples of tensors which keep both kinetic energy density and strain energy density unchanged during the related change of a reference placement. The triples were obtained using transformation rules of strain measures and microinertia tensors under replacement of a reference placement. From the physical point of view, the local material symmetry group consists of such density-preserving transformations of a reference placement, that cannot be experimentally detected. So the constitutive relations become invariant under such transformations. Knowing a priori a material’s symmetry, one can establish a simplified form of constitutive relations. In particular, the number of independent arguments in constitutive relations could be significantly reduced.
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On Effective Bending Stiffness of a Laminate Nanoplate Considering Steigmann–Ogden Surface Elasticity
- Victor Eremeev
- Tomasz Wiczenbach
As at the nanoscale the surface-to-volume ratio may be comparable with any characteristic length, while the material properties may essentially depend on surface/interface energy properties. In order to get effective material properties at the nanoscale, one can use various generalized models of continuum. In particular, within the framework of continuum mechanics, the surface elasticity is applied to the modelling of surface-related phenomena. In this paper, we derive an expression for the effective bending stiffness of a laminate plate, considering the Steigmann–Ogden surface elasticity. To this end, we consider plane bending deformations and utilize the through-the-thickness integration procedure. As a result, the calculated elastic bending stiffness depends on lamina thickness and on bulk and surface elastic moduli. The obtained expression could be useful for the description of the bending of multilayered thin films.
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On homotopies of morphisms and admissible mappings
- Zdzisław Dzedzej
- Tomasz Gzella
The notion of homotopy in the category of morphisms introduced by G´orniewicz and Granas is proved to be equivalence relation which was not clear for years. Some simple properties are proved and a coincidence point index is described.
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On Inadequacy of Sequential Design of Experiments for Performance-Driven Surrogate Modeling of Antenna Input Characteristics
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
Design of contemporary antennas necessarily involves electromagnetic (EM) simulation tools. Their employment is imperative to ensure evaluation reliability but also to carry out the design process itself, especially, the adjustment of antenna dimensions. For the latter, traditionally used parameter sweeping is more and more often replaced by rigorous numerical optimization, which entails considerable computational expenses, sometimes prohibitive. A potentially attractive way of expediting the simulation-based design procedures is the replacement of expensive EM analysis by fast surrogate models (or metamodels). Unfortunately, due to the curse of dimensionality and considerable nonlinearity of antenna characteristics, applicability of conventional modeling methods is limited to structures described by small numbers of parameters within narrow ranges thereof. A recently proposed nested kriging technique works around these issues by allocating the surrogate model domain within the regions containing designs that are of high quality with respect to the selected performance figures. This paper investigates whether sequential design of experiments (DoE) is capable of enhancing the modeling accuracy over one-shot space-filling data sampling originally implemented in the nested kriging framework. Numerical verification carried out for two microstrip antennas indicates that no noticeable benefits can be achieved, which contradicts the common-sense expectations. This result can be explained by a particular geometry of the confined domain of the performance-driven surrogate. As this set consists of nearly-optimum designs, the average nonlinearity of the antenna responses therein is almost location independent, therefore optimum training data allocation should be close to uniform. This is indeed corroborated by our experiments.
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On instabilities and post-buckling of piezomagnetic and flexomagnetic nanostructures
- Mohammad Malikan
- Nikolay S. Uglov
- Victor Eremeev
We focus on the mechanical strength of piezomagnetic beam-like nanosize sensors during post-buckling. An effective flexomagnetic property is also taken into account. The modelled sensor is selected to be a Euler-Bernoulli type beam. Long-range interactions between atoms result in a mathematical model based on the nonlocal strain gradient elasticity approach (NSGT). Due to possible large deformations within a post-buckling phenomenon, the resultant equations are essentially nonlinear. We establish the results using an analytical approach, including a variety of boundary conditions. We visualize the effective response of the designed sensor for several key components. It was obtained that the flexomagnetic effect is meaningful for less flexible boundary conditions. Besides, it was found that the failure originated from post-buckling occurs sooner if the numerical amounts of nonlocal parameter and the strain gradient one are respectively so small and exceedingly large.
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On Nonlinear Bending Study of a Piezo-Flexomagnetic Nanobeam Based on an Analytical-Numerical Solution
- Mohammad Malikan
- Victor Eremeev
Among various magneto-elastic phenomena, flexomagnetic (FM) coupling can be defined as a dependence between strain gradient and magnetic polarization and, contrariwise, elastic strain and magnetic field gradient. This feature is a higher-order one than piezomagnetic, which is the magnetic response to strain. At the nanoscale, where large strain gradients are expected, the FM effect is significant and could be even dominant. In this article, we develop a model of a simultaneously coupled piezomagnetic–flexomagnetic nanosized Euler–Bernoulli beam and solve the corresponding problems. In order to evaluate the FM on the nanoscale, the well-known nonlocal model of strain gradient (NSGT) is implemented, by which the nanosize beam can be transferred into a continuum framework. To access the equations of nonlinear bending, we use the variational formulation. Converting the nonlinear system of differential equations into algebraic ones makes the solution simpler. This is performed by the Galerkin weighted residual method (GWRM) for three conditions of ends, that is to say clamp, free, and pinned (simply supported). Then, the system of nonlinear algebraic equations is solved on the basis of the Newton–Raphson iteration technique (NRT) which brings about numerical values of nonlinear deflections. We discovered that the FM effect causes the reduction in deflections in the piezo-flexomagnetic nanobeam.
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On Radar DoA Estimation and Tilted Rotating Electronically Scanned Arrays
- Michał Meller
- Kamil Stawiarski
We consider DoA estimation in a monopulse radar system employing a tilted rotating array. We investigate the case of nonzero steering angles, in which case the mapping between the target’s azimuth and elevation in the global coordinate system and their counterparts in the array local coordinate system becomes increasingly nonlinear and coupled. Since estimating the azimuth using coherently integrated signals might be difficult because of strong modulation in the difference signal induced by the rotation of the antenna, we develop an iterative approach that alternates between estimating the elevation using coherently integrated signals and estimating the azimuth using unfiltered signals. We also develop a simplified version of the scheme, which employs only one iteration and forms the final estimates by applying simple corrections to results of the first iteration.
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On rotational instability within the nonlinear six-parameter shell theory
- Jacek Chróścielewski
- Francesco Dell’isola
- Victor Eremeyev
- Agnieszka Sabik
Within the six-parameter nonlinear shell theory we analyzed the in-plane rotational instability which oc- curs under in-plane tensile loading. For plane deformations the considered shell model coincides up to notations with the geometrically nonlinear Cosserat continuum under plane stress conditions. So we con- sidered here both large translations and rotations. The constitutive relations contain some additional mi- cropolar parameters with so-called coupling factor that relates Cosserat shear modulus with the Cauchy shear modulus. The discussed instability relates to the bifurcation from the static solution without rota- tions to solution with non-zero rotations. So we call it rotational instability. We present an elementary discrete model which captures the rotational instability phenomenon and the results of numerical anal- ysis within the shell model. The dependence of the bifurcation condition on the micropolar material parameters is discussed.
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On Solvability of Boundary Value Problems for Elastic Micropolar Shells with Rigid Inclusions
- Victor Eremeev
- Leonid Lebedev
In the framework of the linear theory of micropolar shells, existence and uniqueness theorems for weak solutions of boundary value problems describing small deformations of elastic micropolar shells connected to a system of absolutely rigid bodies are proved. The definition of a weak solution is based on the principle of virial movements. A feature of this problem is non-standard boundary conditions at the interface between the shell and solids.
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On stress singularity near the tip of a crack with surface stresses
- Nikolai Gorbushin
- Victor Eremeev
- Gennady Mishuris
In the framework of the simplified linear Gurtin–Murdoch surface elasticity we discuss a singularity of stresses and displacements in the vicinity of a mode III crack. We show that inhomogeneity in surface elastic properties may significantly affect the solution and to change the order of singularity. We also demonstrate that implicitly or explicitly assumed symmetry of the problem may also lead to changes in solutions. Considering various loading and symmetry conditions we show that the stresses may have logarithmic or square root singularity or be bounded in the vicinity of a crack tip.
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On Surface Kinetic Constitutive Relations
- Victor Eremeev
- Leonid Lebedev
In the framework of the strain gradient surface elasticity we discuss a consistent form of surface kinetic energy. This kinetic constitutive equation completes the statement of initial–boundary value problems. The proposed surface kinetic energy density is the most general function consistent with the constitutive relations in bulk. As the surface strain energy depends on the surface deformation gradient and its gradient, the kinetic energy is a quadratic function of the velocity and its surface gradient.
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On the connected and weakly convex domination numbers
- Magdalena Lemańska
- Magda Dettlaff
- Dorota Osula
- Maria Jose Souto Salorio
In this paper we study relations between connected and weakly convex domination numbers. We show that in general the difference between these numbers can be arbitrarily large and we focus on the graphs for which a weakly convex domination number equals a connected domination number. We also study the influence of the edge removing on the weakly convex domination number, in particular we show that a weakly convex domination number is an interpolating function.
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On the Consumption of Multimedia Content Using Mobile Devices: a Year to Year User Case Study
- Przemysław Falkowski-Gilski
In the early days, consumption of multimedia content related with audio signals was only possible in a stationary manner. The music player was located at home, with a necessary physical drive. An alternative way for an individual was to attend a live performance at a concert hall or host a private concert at home. To sum up, audio-visual effects were only reserved for a narrow group of recipients. Today, thanks to portable players, vision and sound is at last available for everyone. Finally, thanks to multimedia streaming platforms, every music piece or video, e.g. from one’s favourite artist or band, can be viewed anytime and everywhere. The background or status of an individual is no longer an issue. Each person who is connected to the global network can have access to the same resources. This paper is focused on the consumption of multimedia content using mobile devices. It describes a year to year user case study carried out between 2015 and 2019, and describes the development of current trends related with the expectations of modern users. The goal of this study is to aid policymakers, as well as providers, when it comes to designing and evaluating systems and services.
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On the Correlation of Lignocellulosic Filler Composition with the Performance Properties of Poly(ε-Caprolactone) Based Biocomposites
- Aleksander Hejna
- Mohamed Sulyman
- Marta Przybysz-Romatowska
- Mohammad Saeb
- Marek Klein
- Krzysztof Formela
In this work, three types of agricultural waste: olive stones (OS), date seed (DS) and wheat bran (WB) were applied as potential lignocellulosic fillers in poly(ε-caprolactone) (PCL) based biocomposites. Differences in composites’ performance were related to the higher content of proteins, noted for WB comparing to other fillers applied, which enhanced plasticization of PCL matrix. The mechanical properties of biocomposites were significantly affected by the agricultural waste fillers. Use of WB caused an obvious, even 25% decrease of tensile strength and hardness, which could be explained on account of glass transition temperature depletion and weaker matrix–filler interfacial interactions. Such phenomenon also increased water uptake of PCL/WB composites by more than 100%, while for PCL/OS and PCL/DS systems only for about 50%. Thermogravimetric analysis revealed that all investigated composites can be effectively processed without thermal decomposition. Generally, the outcome of this work demonstrated that OS, DS, and WB could be applied as promising lignocellulosic fillers used in manufacturing of high-performance polymer biocomposites.
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On the Dynamics of a Visco–Piezo–Flexoelectric Nanobeam
- Mohammad Malikan
- Victor Eremeev
The fundamental motivation of this research is to investigate the effect of flexoelectricity on a piezoelectric nanobeam for the first time involving internal viscoelasticity. To date, the effect of flexoelectricity on the mechanical behavior of nanobeams has been investigated extensively under various physical and environmental conditions. However, this effect as an internal property of materials has not been studied when the nanobeams include an internal damping feature. To this end, a closed-circuit condition is considered taking converse piezo–flexoelectric behavior. The kinematic displacement of the classical beam using Lagrangian strains, also applying Hamilton’s principle, creates the needed frequency equation. The natural frequencies are measured in nanoscale by the available nonlocal strain gradient elasticity model. The linear Kelvin–Voigt viscoelastic model here defines the inner viscoelastic coupling. An analytical solution technique determines the values of the numerical frequencies. The best findings show that the viscoelastic coupling can directly affect the flexoelectricity property of the material.
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On the effective properties of foams in the framework of the couple stress theory
- Andrzej Skrzat
- Victor Eremeev
In the framework of the couple stress theory, we discuss the effective elastic properties of a metal open-cell foam. In this theory, we have the couple stress tensor, but the microrotations are fully described by displacements. To this end, we performed calculations for a representative volume element which give the matrices of elastic moduli relating stress and stress tensors with strain and microcurvature tensors.
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On the electronic structure of methyl butyrate and methyl valerate
- Małgorzata Śmiałek-Telega
- Denis Duflot
- Nykola C. Jones
- Søren Hoffmann
- Lucia Zuin
- Michael MacDonald
- Nigel J. Mason
- Paulo Limão-Vieira
We present novel results of the analysis of the electronic structure of two aliphatic esters: methyl butyrate and methyl valerate. High-resolution photoabsorption spectra were collected and analyzed over the energy range 4.0–10.8 eV and showed for both the molecules not only a clear band of the HOMO to LUMO transition, but also vibronic structure associated with the first Rydberg-valence transition. Photoelectron spectra recorded from 9 to over 28 eV revealed many ionization states with the first adiabatic ionization energies found to be 9.977 eV and 9.959 eV for methyl butyrate and methyl valerate, respectively. Ab initio calculations have been performed in order to help assign the photoabsorption and photoelectron features. Photolysis life times in the atmosphere were calculated revealing that photolysis is not competitive over hydroxyl radical scavenging in the process of removal of these esters from the atmosphere.
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On the Existence of Homoclinic Type Solutions of a Class of Inhomogenous Second Order Hamiltonian Systems
- Jakub Ciesielski
- Joanna Janczewska
- Nils Waterstraat
We show the existence of homoclinic type solutions of a class of inhomogenous second order Hamiltonian systems, where a C1-smooth potential satisfies a relaxed superquadratic growth condition, its gradient is bounded in the time variable, and a forcing term is sufficiently small in the space of square integrable functions. The idea of our proof is to approximate the original system by time-periodic ones, with larger and larger time-periods. We prove that the latter systems admit periodic solutions of mountain-pass type, and obtain homoclinic type solutions of the original system from them by passing to the limit (in the topology of almost uniform convergence) when the periods go to infinity.
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On the geometrically nonlinear vibration of a piezo-flexomagnetic nanotube
- Mohammad Malikan
- Victor Eremeev
In order to describe the behavior of thin elements used in MEMS and NEMS, it is essential to study a nonlinear free vibration of nanotubes under complicated external fields such as magnetic environment. In this regard, the magnetic force applied to the conductive nanotube with piezo-flexomagnetic elastic wall is considered. By the inclusion of Euler-Bernoulli beam and using Hamilton’s principle, the equations governing the system are extracted. More importantly, a principal effect existed in a nonlinear behavior such as axial inertia is thoroughly analyzed which is not commonly investigated. We then consider the effects of nanoscale size using the nonlocal theory of strain gradient (NSGT). Hereafter, the frequencies are solved as semi-analytical solutions on the basis of Rayleigh-Ritz method. The piezo-flexomagnetic nanotube (PF-NT) is calculated with different boundary conditions. In order to validate, the results attained from the present solution have been compared with those available in the open literature. We realized that the nonlinear frequency analysis is so significant when a nanotube has fewer degrees of freedom at both ends, and its length is long.
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On the non-linear dynamics of torus-shaped and cylindrical shell structures
- Shahriar Dastjerdi
- Bekir Akgöz
- Ömer Civalek
- Mohammad Malikan
- Victor Eremeev
In this study, the non-linear dynamic analysis of torus-shaped and cylindrical shell-like structures has been studied. The applied material is assumed as the functionally graded material (FGM). The structures are considered to be used for important machines such as wind turbines. The effects of some environmental factors on the analysis like temperature and humidity have been considered. The strain field has been calculated in general form and in continue the dynamic governing equations of torus structure have been derived based on the first-order shear deformation theory. The rotation around two independent axes in the torus coordinate system is considered and time-dependent equations are solved using SAPM semi-analytical method. The stresses and deformations generated in the torus and cylindrical shaped structures are plotted. The rotation of structures has been attended due to some transportation purposes. The effect of internal pressures as well as rotational speed at torus and cylindrical structures has been investigated in several numerical diagrams. The results are presented in the form of graphs that consider the rotational effects, loading, thermal and humid (hygro-thermal) environments, and size of the structures. This research can provide scientific perspectives to researchers who will examine the dynamic analysis of torus and cylindrical shaped structures.
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On the plastic buckling of curved carbon nanotubes
- Mohammad Malikan
This research, for the first time, predicts theoretically static stability response of a curved carbon nanotube (CCNT) under an elastoplastic behavior with several boundary conditions. The CCNT is exposed to axial compressive loads. The equilibrium equations are extracted regarding the Euler–Bernoulli displacement field by means of the principle of minimizing total potential energy. The elastoplastic stress-strain is concerned with Ramberg–Osgood law on the basis of deformation and flow theories of plasticity. To seize the nano-mechanical behavior of the CCNT, the nonlocal strain gradient elasticity theory is taken into account. The obtained differential equations are solved using the Rayleigh–Ritz method based on a new admissible shape function which is able to analyze stability problems. To authorize the solution, some comparisons are illustrated which show a very good agreement with the published works. Conclusively, the best findings confirm that a plastic analysis is crucial in predicting the mechanical strength of CCNTs.
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On the preestimation technique and its application to identification of nonstationary systems
- Maciej Niedźwiecki
- Artur Gańcza
- Marcin Ciołek
The problem of noncausal identification of a nonstationary stochastic FIR (finite impulse response) sys- tem is reformulated, and solved, as a problem of smoothing of preestimated parameter trajectories. Three approaches to preestimation are critically analyzed and compared. It is shown that optimization of the smoothing operation can be performed adaptively using the parallel estimation technique. The new approach is computationally attractive and yields estimation results that are comparable or better than those provided by the state-of-the-art local basis function approach and the multi- resolution wavelet approach.
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
- Michał Laskowski
- Sławomir Ambroziak
- Luis M. Correia
- Krzysztof Świder
In this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting and receiving antenna heights and relative polarisation of both antennas. It is proved that the Generalised Additive Model allows for mean path loss estimation with a higher accuracy in comparison with Linear Regression. The obtained mean error is 0 dB, the root mean square error is 5.52 dB and the adjusted coefficient of determination is 61.2%.
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On the well posedness of static boundary value problem within the linear dilatational strain gradient elasticity
- Victor Eremeev
- Sergey Lurie
- Yury Solyaev
- Francesco dell'Isola
In this paper, it is proven an existence and uniqueness theorem for weak solutions of the equilibrium problem for linear isotropic dilatational strain gradient elasticity. Considered elastic bodies have as deformation energy the classical one due to Lamé but augmented with an additive term that depends on the norm of the gradient of dilatation: only one extra second gradient elastic coefficient is introduced. The studied class of solids is therefore related to Korteweg or Cahn–Hilliard fluids. The postulated energy naturally induces the space in which the aforementioned well-posedness result can be formulated. In this energy space, the introduced norm does involve the linear combination of some specific higher-order derivatives only: it is, in fact, a particular example of anisotropic Sobolev space. It is also proven that aforementioned weak solutions belongs to the space H1(div,V), i.e. the space of H1 functions whose divergence belongs to H1. The proposed mathematical frame is essential to conceptually base, on solid grounds, the numerical integration schemes required to investigate the properties of dilatational strain gradient elastic bodies. Their energy, as studied in the present paper, has manifold interests. Mathematically speaking, its singularity causes interesting mathematical difficulties whose overcoming leads to an increased understanding of the theory of second gradient continua. On the other hand, from the mechanical point of view, it gives an example of energy for a second gradient continuum which can sustain externally applied surface forces and double forces but cannot sustain externally applied surface couples. In this way, it is proven that couple stress continua, introduced by Toupin, represent only a particular case of the more general class of second gradient continua. Moreover, it is easily checked that for dilatational strain gradient continua, balance of force and balance of torques (or couples) are not enough to characterise equilibrium: to this aim, externally applied surface double forces must also be specified. As a consequence, the postulation scheme based on variational principles seems more suitable to study second gradient continua. It has to be remarked finally that dilatational strain gradient seems suitable to model the experimentally observed behaviour of some material used in 3D printing process.
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One-step recovery of REE oxalates in electro-leaching of spent NdFeB magnets
- Irina Makarova
- Jacek Ryl
- Zhi Sun
- Irina Kurilo
- Karolina Górnicka
- Markku Laatikainen
- Eveliina Repo
Recovery of rare-earth elements (REEs) from spent NdFeB magnets is receiving great attention because of high amount of neodymium and potential risk of environmental pollution. In this study, a novel environment-friendly hydrometallurgical route is proposed for efficient recovery of REEs during electrochemical leaching with sulfuric and oxalic acids. With proper adjustment of the electrolyte composition and operating conditions, effective separation of different elements is observed; a compact layer of REE oxalates in a purity of up to 93% is obtained on the cathode, while iron remains in the solution and as solid residue for further recovery. The mechanisms during the electro-leaching process were subsequently investigated and we propose that cathodic deposition of the REEs is due to electrostatic attraction of the REE-oxalate particles on the cathode. With this finding, selective recovery of REEs from spent magnets can be achieved. This study provides a new insight on electronic waste recycling by implementing principles of electrochemistry.
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On-line measurement of wood surface smoothness
- Jakub Sandak
- Kazimierz Orłowski
- Anna Sandak
- Daniel Chuchała
- Piotr Taube
The latest progress in the field of optics and microelectronics resulted in development of new generation vision systems capable of scanning surface topography with very high sampling frequencies. The blue color of illuminating light as well as novel systems for controlling ultra-thin laser line thickness allows measurement of the porous surface of wood with a triangulation method. Three alternative sensors were tested here in order to verify their suitability for determination of surface topography in the industrial environment. The scanning head was installed at the exit zone of the four-side profiling moulder and was set to scrutinize the wood surface shape line-by-line, immediately after profiling. The sensor was also tested for automatic detection of surface defects appearing on elements after sanding, wetting and painting with diverse finishing products. The set of pilot test results, together with an original algorithm for real-time surface defects detection, is presented.
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Open Data Capability Architecture - An Interpretive Structural Modeling Approach
- Adegboyega Ojo
Despite of increasing availability of open data as a vital organizational resource, large numbers of startups and organizations fail when it comes to utilizing open data effectively. This shortcoming is attributable to the poor understanding of what types of capabilities are required to successfully conduct data related activities. At the same time, research on open data capabilities and how they relate to one another remains sparse. Guided by extant literature, interviews of these organizations, and drawn from Interpretive Structural Modeling (ISM) approach which are pair comparison methods to evolve hierarchical relationships among a set of elements to convert unclear and unstructured mental models of systems into well-articulated models that act as base for conceptualization and theory building, this study explores open data capabilities and the relationships and the structure of the dependencies among these areas. Findings from this study reveal hitherto unknown knowledge regarding how the capability areas relate one another in these organizations. From the practical standpoint, the resulting architecture has the potential to transform capability management practices in open data organizations towards greater competitiveness through more flexibility and increased value generation. From the research point of you, this paper motivates theory development in this discipline
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Open-Source Coprocessor for Integer Multiple Precision Arithmetic
- Kamil Rudnicki
- Tomasz Stefański
- Wojciech Żebrowski
This paper presents an open-source digital circuit of the coprocessor for an integer multiple-precision arithmetic (MPA). The purpose of this coprocessor is to support a central processing unit (CPU) by offloading computations requiring integer precision higher than 32/64 bits. The coprocessor is developed using the very high speed integrated circuit hardware description language (VHDL) as an intellectual property (IP) core. Therefore, it can be implemented within field programmable gate arrays (FPGAs) at various scales, e.g., within a system on chip (SoC), combining CPU cores and FPGA within a single chip as well as FPGA acceleration cards. The coprocessor handles integer numbers with precisions in the range 64 bits–32 kbits, with the limb size set to 64 bits. In our solution, the sign-magnitude representation is used to increase the efficiency of the multiplication operation as well as to provide compatibility with existing software libraries for MPA. The coprocessor is benchmarked in factorial ( n! ), exponentiation ( nn ) and discrete Green’s function (DGF) computations on Xilinx Zynq-7000 SoC on TySOM-1 board from Aldec. In all benchmarks, the coprocessor demonstrates better runtimes than a CPU core (ARM Cortex A9) executing the same computations using a software MPA library. For sufficiently large input parameters, our coprocessor is up to three times faster when implemented in FPGA on SoC, rising to a factor of ten in DGF computations. The open-source coprocessor code is licensed under the Mozilla Public License.
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Open-source software (OSS) and hardware (OSH) in UAVs
- Paweł Burdziakowski
- Navid Razmjooy
- Vania Estrela
- Jude Hemanath
The popularity of the Open Source Tool (OST) has expanded significantly. This is the case for Unmanned Aerial Vehicles (UAVs) based on open-source hardware (OSH) as well. Open-source software (OSS) and OSH can be applied in a wide range of applications and can improve several technologies. The chapter begins with an introduction to OSS depicting its rationale, description of fundamental differences between OSS and proprietary software (PS), what benefits OSSs provide to overall UAV community, the motives leading people to pick up an OSS instead of a PS, which helps the academic and research community. This chapter also covers some OSSs used within the UAV community to support all aspects of UAV technology and the Remote Sensing (RS) and photogrammetry data post-processing chain. It is possible to build fully autonomous and operational UAV based only on OSH and OSS. The chapter describes the state of the art for OSS widely used in UAV technology, the software used in all aspects of UAV technology such as ARDUPILOT-based Autopilot firmware, MISSION PLANNER-based ground station, OPENTX transmitter software, MINIM On-Screen Data (OSD) software, Open Drone Map photogrammetry data processing suite, Web drone data-processing suite WebODM. This chapter describes several concepts and characteristics of open software/hardware, built-in functions, and particular features as well as platform requirements. A typical UAV photogrammetry workflow for drone construction with flight planning/execution and OSS data processing is provided.
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Operation of the Hybrid Photovoltaic-Battery System on the Electricity Market—Simulation, Real-Time Tests and Cost Analysis
- Robert Małkowski
- Marcin Jaskólski
- Wojciech Pawlicki
This paper presents research on a hybrid photovoltaic-battery energy storage system, declaring its hourly production levels as a member of a balancing group submitting common scheduling unit to the day-ahead market. It also discusses the variability of photovoltaic system generation and energy storage response. The major research questions were whether the operation of a hybrid photovoltaic-battery energy storage system is viable from the technical and economic viewpoint and how to size battery energy storage for that purpose. The DIgSILENT PowerFactory environment was used to develop the simulation model of postulated hybrid system. Then, tests were conducted on real devices installed in the LINTE^2 laboratory at Gdańsk University of Technology, Poland. Firstly, power generation in the photovoltaic system was modeled using hardware in the loop technique and tested in cooperation with emulated photovoltaic and real battery energy storage system (lithium-ion battery, 25 kWh). Secondly, a real photovoltaic power plant (33 kW) and real battery energy storage were applied. The results obtained from laboratory experiments showed that market operation of hybrid photovoltaic-battery energy storage system is feasible. However, developing a control strategy constitutes a great challenge, as the operator is forced to intervene more frequently than the simulation models indicate in order to keep the parameters of battery storage within accepted ranges, especially in view of a sudden weather breakdown. Levelized cost of electricity from photovoltaic-battery energy storage system varied from 314 to 455 $/MWh, which has proven to be from two to three times higher than the current annual average day-ahead market price in Poland.
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Opinia historyczno-konserwatorska o projekcie koncepcyjnym przebudowy wnętrz zabytkowego budynku centrali Banku Gospodarstwa Krajowego w Warszawie autorstwa przcowni JEMS Architekci z 2020 r. w świetle ochrony modernistycznego dziedzictwa kulturowego
- Maria Sołtysik
Opinia o projekcie koncepcyjnym przebudowy wnętrz zabytkowego budynku centrali Banku Gospodarstwa Krajowego w Warszawie autorstwa pracowni JEMS Architekci z 2020 r została wykonana w świetle ochrony modernistycznego dziedzictwa kulturowego. Opinia zawiera 6 głównych rozdziałów: 1. Informacje wstępne; 2. Główne kierunki i idee modernizmu w architekturze okresu międzywojennego; 3. Historyczne wnętrza gmachu centrali BGK - wybitne dzieło polskiego modernizmu, symbol nowoczesności Polski międzywojennej i świadectwo ważnej roli Banku w życiu gospodarczym kraju; 4. Cel konserwatorski przebudowy wnętrz gmachu BGK i rola w tym procesie współczesnego BGK jako gospodarza obiektu; 5. Specyfika ochrony dziedzictwa modernizmu i opinia dotycząca głównych wytycznych ochrony konserwatorskiej wnętrz BGK w świetle celu konserwatorskiego przebudowy; 6. Analiza projektu koncepcyjnego przebudowy wnętrz centrali BGK autorstwa JEMS Architekci pod kątem zachowania historycznego dziedzictwa materialnego i niematerialnego wnętrz BGK z lat 1928-31; 7. Podsumowanie opinii. Wykonana opinia stała się podstawą dla zasadniczej korekty pierwotnego projektu koncepcyjnego przebudowy wnętrz gmachu BGK i podstawą do wykonania realizowanego obecnie projektu budowlanego tej przebudowy.
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Opportunities and challenges for exploiting drones in agile manufacturing systems
- Mariusz Deja
- Mieczysław S. Siemiątkowski
- George-Ch. Vosniakos
- Gerasimos Maltezos
Drones have become an advanced supply chain implementation instrument, especially in connecting warehouses to outlet points or even individual customers. However, their potential application in an intra-logistics framework has not been studied, let alone explored so far. Modeling and simulations in virtual environments can help explore and evaluate the opportunities for practical and profitable applications of drones in manufacturing systems. This paper considers use of drones in replacing or supplementing industrial robots, transportation systems and humans in factories, especially regarding agile manufacturing under the requirements of flexibility, reconfigurability and collaboration. Currently available drone technology regarding positioning, navigation and communication is examined in order to define possible individual tasks and general operations that they can perform, as well as pertinent limitations. A typical scenario of a flexible manufacturing system is simulated and conceptually presented for discussing drone integration and missing links. The main issues refer to mechanical integration with machinery and parts, information integration in the manufacturing system, especially in an Industrial Internet of Things direction, scheduling and collaboration with humans and robots including safety.
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Optical sensor of a person sitting on a chair and dressed in multi-layered clothes vital signs monitoring
- Adam Bujnowski
- Mariusz Kaczmarek
- Kamil Osiński
- Michal Gramowski
- Jerzy Wtorek
An optoelectronic device enhancing a smart chair functionality is presented in the paper. Its essential purpose is a detection of a sitting person presence on the chair by means of detecting the vital signs. Additionally, it could be used for determining of clothes layer parameters useful in adjusting a system of a capacitive electrocardiography.
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Optimisation of turbine shaft heating process under steam turbine run-up conditions
- Krzysztof Dominiczak
- Marta Drosińska-Komor
- Romuald Rządkowski
- Jerzy Głuch
An important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured for fixing the rotor blades. The extreme stresses in this place occur during the start-up and the shaft heating to normal operating temperature. The process needs optimisation. Optimization tasks are multidisciplinary issues and can be carried out using different methods. In recent years, particular attention in optimisation has been paid to the use of artificial intelligence methods. Among them, a special role is assigned to genetic algorithms. The paper presents a genetic algorithm method to optimise the steam turbine shaft heating process during its start-up phase. The presented optimization task of this algorithm is to carry out the process of the shaft heating as soon as possible at the conditions of not exceeding the stresses at critical locations at any heating phase.
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OPTIMISING RIG DESIGN FOR SAILING YACHTS WITH EVOLUTIONARY MULTIOBJECTIVE ALGORITHM
- Mikołaj Pawłusik
- Rafał Szłapczyński
- Artur Karczewski
The paper presents a framework for optimising a sailing yacht rig using Multi-objective Evolutionary Algorithms and for filtering obtained solutions by means of a Multi-criteria Decision Making method. A Bermuda sloop with discontinuous rig is taken under consideration as a model rig configuration. It has been decomposed into its elements and described by a set of control parameters to form a responsive model which can be used for optimisation purposes. Considering the contradictory nature of real optimisation objectives, a multi-objective approach has been chosen to address this issue. Once the optimisation process is over, a Multi-criteria Decision Making method based on a w-dominance relation is applied for filtering out the most interesting solutions from the obtained Pareto set. The proposed method has been implemented, and selected results are provided and discussed.
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Optimization of liquid chromatographic separation of pharmaceuticals within green analytical chemistry framework
- Aysegul Dogan
- Marek Tobiszewski
The contribution is aimed at the development of methodology that allows to consider green analytical chemistry criteria during optimization of liquid chromatographic separation with design of experiment. The objectives of the optimization are maximization of peak areas of five non-steroid anti-inflammatory drugs, maximization of resolution between peaks, with simultaneous shortening of chromatographic separation time and minimization of mobile phase environmental impact. This is obtained with design of experiment to consider many experimental conditions and Derringer's desirability function to combine many optimization objectives. The possibilities of introduction different green analytical chemistry metrics are discussed and the methodology of mobile phase greenness assessment is proposed. The optimal response for all objectives is obtained for 0.96 mL min−1 of mobile phase flow rate, 61% of MeOH content, temperature of 25°C and pH equal to 4.5. The separation takes less than 9 min.
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Optimization of Stabilizing Systems in Protection of Cultural Heritage: The Case of the Historical Retaining Wall in the Wisłoujście Fortress
- Piotr Chudoba
- Jarosław Przewłócki
- Piotr Samól
- Lesław Zabuski
The aim of the paper is to propose new quantitative criteria for selecting the optimal method of securing and repairing a historical object, which take into account Structural, Conservation and Architectural aspects (the S–C–A method). Construction works on cultural heritage sites tend to be challenging and require an interdisciplinary approach. Therefore, they are strictly related to the philosophy of sustainable development which seeks adequate proportions between factors indicated on the natural and social environment. Optimization of several systems stabilizing retaining structure that are a historic object was considered in the paper. Appropriate formulas for scores meeting additional conservation and aesthetic requirements were proposed. The method is used in the stabilization of the brick retaining wall, a part of the Wisłoujście Fortress located in Gdańsk, Poland. In order to compute the displacement of the wall and its stability, numerical analysis was performed by the two-dimensional explicit Finite Difference Method (using the FLAC2D software). The algorithm proposed could be beneficial to the protection of cultural heritage since it could also be applied to other structures, such as roof trusses, masonry walls, pillars, etc.
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Optimization of Wireless Networks for Resilience to Adverse Weather Conditions
- Michał Pióro
- Emma Fitzgerald
- Ilya Kalesnikau
- Dritan Nace
- Jacek Rak
In this chapter, we consider how adverse weather conditions such as rain or fog affect the performance of wireless networks, and how to optimize these networks so as to make them robust to these conditions. We first show how to analyze the weather conditions in order to make them useful for network optimization modelling. Using an example realistic network, we show how to optimize two types of wireless networks: free-space optical (FSO) networks and wireless mesh networks (WMN). The key difference between the two network types is that in WMNs, links interfere with each other, while in FSO networks, link rates may be assumed independent. We formulate optimization problems to protect each network type against adverse weather conditions, discuss solution methods to solve them and present a numerical study illustrating the considerations of the chapter.
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Optimized Space-Vector Modulation Schemes for Five-Phase Precision Low-Speed Drives with Minimizing the Stator Current Ripple
- Valentin Tomasov
- Aleksander Usoltsev
- Denis Vertegel
- Paweł Szczepankowski
- Ryszard Strzelecki
- Nikolai Poliakov
One of the main ways to improve the quality of a precision electric drive is minimization of the stator current pulsations generated by the voltage inverter. The solution of this problem can be achieved by using of multiphase inverters, as well as improving control algorithms. This paper considers the influence of the space-vector modulation algorithm with different switching sequences of basic vectors on the stator current pulsations generated by the five-phase voltage inverter.
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Optymalizacja prędkości obrotowej narzędzia podczas frezowania przedmiotów wielkogabarytowych
- Krzysztof Kaliński
- Marek Galewski
- Michał Mazur
- Natalia Stawicka-Morawska
Przedstawiono nową metodę wyznaczania optymalnej prędkości obrotowej narzędzia podczas frezowania przedmiotów wielkogabarytowych. Parametry modelu obliczeniowego (modalnego) przedmiotu obrabianego są wyznaczane z wykorzystaniem jedynie eksperymentalnej analizy modalnej. To ostatnie umożliwia eliminację pracochłonnego etapu modelowania przedmiotu, jakim jest stosowane dotychczas tworzenie i walidacja modelu MES. Otrzymany w ten sposób model jest następnie wykorzystywany do symulacji procesu obróbkowego. Ponadto, podczas symulacji uwzględniany jest model obliczeniowy wirującego narzędzia oraz przyjęty model dynamiki procesu skrawania. Skuteczność metody potwierdzono na podstawie wyników badań eksperymentalnych procesu.
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Orbital blowout trauma occurring at the workplace – clinical, biomechanical and legal aspects
- Andrzej Skorek
- Paweł Kłosowski
- Krzysztof Żerdzicki
- Piotr Skorek
- Paweł Lemski
- Marcin Zmuda Trzebiatowski
Introduction and objective: Craniofacial injury at the workplace may lead to orbital blowout fractures. The aim of the study is the development of own numerical model of the eye orbit, assessment of the damage zones, and comparing them with clinical examinations. In addition, the current legal status of patients after injuries is presented Material and methods: In laboratory tests performed on bones collected from the upper and medial orbital wall (examination on fresh corpses), the Young’s modulus was determined for these bones. Based on the CT image, a numerical model of the eye orbit was created. The damage zones within the eye socket were assessed after a blow (dynamic model) to the inferior and lateral walls, and only to the inferior wall. Comparative clinical material were 9 patients with orbital blowout fracture treated at the Clinic of Otolaryngology Results: Experiment 1: the damage zone covered an area of 0.54cm2, and was located medially and laterally from the infraorbital nerve canal. Experiment 2: the damage zone was smaller – 0.38 cm2, and located medially to the infraorbital nerve canal. The results obtained in the experiment were compared with the CT image of the eye sockets of patients after injuries. On this basis, presumptions were made concerning the mechanism of the trauma. Conclusions: The finite element method is a good tool for assessing the pathomechanism of trauma, as well as for an attempt to determine the circumstances of the event. Based on analysis of the numerical and clinical images, the necessity for using protective measures which absorb the impact to the inferior wall and temporal areas should be emphasised, as well as the fact that using merely goggles is insufficient protection of the eye orbit.
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Organisational Competence vs Transferability of Knowledge in Cluster Organisations and Technology Parks
- Anna Lis
- Jolanta Žemgulienė
Purpose. The main paper aims to evaluate the impact of organisational competence on knowledge and information flows within cluster organisations and technology parks, with particular emphasis on innovative content knowledge. The paper addresses the research question: “What set of competencies of cooperating companies allows access to information and knowledge in cluster and parks structures?" Methodology. The authors report their findings from a quantitative study carried out in four cluster organisations and three technology parks functioning in Poland. The research sample covered a total of 269 enterprises: 132 cluster members and 137 park tenants. The primary method of data collection was a survey questionnaire. Data analysis was conducted using the interdependence of variables, ANOVA, and logistic regression. Results. The research showed that the surveyed enterprises from both analysed groups preferred cooperation with partners of a similar level of competence development and the same or complementary scope of competence. This set of competencies of cooperating organisations also guaranteed better access to information and knowledge resources, including confidential information and new knowledge. This study additionally indicated that the knowledge creation activities performed by the cooperating cluster organisations depended on the proximity of the competencies of organisations as well as on the nature of the information, disseminated within the cluster organisations. The theoretical contribution. The theoretical contribution is related to the results obtained by analysing the phenomenon of information and knowledge dissemination in cluster and park structures, revealing the impact made by the competence proximity of cooperating organisations on the access to this such resources. Thus, the findings supplement the state-of-the-art knowledge of the concept of industrial clusters by presenting a broader view on cooperation developed in geographical proximity, based on a set of various partner competencies.
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Organizacja systemu opieki nad seniorami wyzwaniem dla samorządów lokalnych
- Anita Richert-Kaźmierska
A significant part of the activities undertaken so far under the senior policy, also at the local level, have been focused on seniors’ social (physical and educational) activation. The growing number of the oldest seniors, with limited independence, living alone in single‑person households, away from their families, will force the policy priorities to be reoriented in such a way as to develop efforts to provide different types of support and care for older citizens. The results of research carried out by different researchers confirm that the system of care for seniors with independence restrictions, based mainly on the family members support, is no longer applicable. However, finding a good solution in new conditions will be extremely difficult. First of all, due to the seniors’ preferences (the desire to spend old age in their own home, in familiar surroundings), social conditions and family relationships (singularization in old age, loosening family and social relationships, transferring social relationships into the virtual sphere inaccessible for many seniors), labor market situation (staff deficit in the care system) and public finances (the need to rationalize the growing public expenditure related to the provision of health and care services). The aim of the article is to present selected aspects of seniors’ care system organization in Poland in local territorial units’ perspective. In the article author presents the results of literature analysis of seniors’ care system in Poland, discusses the results of an interview conducted among the seniors of one of the Pomeranian communes regarding availability of care from the closest family members, as well as proposes the concept of organizing the local care system for seniors
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Organizational Wisdom: The Impact of Organizational Learning on the Absorptive Capacity of an Enterprise
- Agata Pierścieniak
- Monika Stelmaszczyk
Purpose: In this article, we analyze the concept of organizational wisdom, indicating its key elements and verifieng the relationships between them. Design/Methodology/Approach: The study was conducted at Vive Textile Recycling Sp. z o.o in Poland. Empirical data was collected from 138 managers using the PAPI technique. Structural equation modelling (SEM) was performed to test the research hypotheses. Additionally, the significance of indirect effects was checked, using the bootstrap method. Findings: Our findings show that organizational wisdom can, from the perspective of management sciences, be considered as a configuration of two elements: organizational learning and absorptive capacity. Our analysis shows that exploitative organizational learning plays an important role in shaping both potential and realized absorptive capacity. Exploratory organizational learning, in contrast, only affects the realized absorptive capacity. Practical Implications: Our research in practice will allow managers to understand that for the company to successfully achieve its goals, considering the changing environment, it should show organizational wisdom. To shape the ability to acquire, assimilate, transform, and make use of valuable external knowledge, they ought to rely on procedures (processes, databases, competences, etc.) that they know well. Their recent procedures or processes will only be capable of influencing their ability to transform and apply external knowledge. Originality/Value: The value of our research is drawing attention to the categories of organizational wisdom, which is not often analyzed in management sciences. The originality of our considerations consists in our attempt to describe the phenomenon not only by indicating its main elements, but also by establishing the relationship between them.
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Oscylacyjna metoda oceny oporu toczenia opon samochodowych na nawierzchniach drogowych o różnej teksturze i sztywności
- Wojciech Owczarzak
Opór toczenia jest jednym z trudniejszych do wyznaczenia parametrów opon samochodowych. Jest to spowodowane tym, iż w przypadku nowoczesnych opon siła oporu toczenia odpowiada 0,5–1% obciążenia opony, dlatego pomiary bardzo małych sił muszą być wykonywane w silnie obciążonym układzie. Stanowi to ogromny problem, szczególnie w warunkach drogowych. Pomiary laboratoryjne są łatwiejsze do wykonania, ze względu na możliwość kontrolowania warunków otoczenia, jednakże w większości przypadków maszyny bieżne nie mogą być wyposażone w prawdziwe nawierzchnie drogowe. Zazwyczaj są to stalowe bębny lub w najlepszym wypadku bębny pokryte replikami nawierzchni. Niniejsza rozprawa doktorska opisuje laboratoryjną metodę oceny oporu toczenia, którą można zastosować do wstępnej oceny nawierzchni drogowych (na podstawie małych próbek nawierzchni) oraz opon. Metoda opiera się na pośrednim pomiarze strat energetycznych występujących w wyniku cyklicznego dociskania opony do nawierzchni, wymuszonego swobodnym spadaniem powodującym oscylacje układu zawierającego masę, sprężystość i tłumienie.
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Otopy Classification of Gradient Compact Perturbations of Identity in Hilbert Space
- Piotr Bartłomiejczyk
- Piotr Nowak-Przygodzki
We prove that the inclusion of the space of gradient local maps into the space of all local maps from Hilbert space to itself induces a bijection between the sets of the respective otopy classes of these maps, where by a local map we mean a compact perturbation of identity with a compact preimage of zero.
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Outsourcing w wybranych podmiotach leczniczych województwa pomorskiego.
- Mateusz Muchlado
Celem badawczym, przyjętym w niniejszej pracy jest identyfikacja procesów zlecanych na zewnątrz w badanej populacji wraz z czynnikami warunkującymi ich skuteczność. Celem utylitarnym jest opracowanie narzędzia umożliwiającego dobór dostawców oraz ocenę procesów poddanych outsourcingowi. W rozdziale pierwszym pracy omówiono pojęcie outsourcingu oraz jego wykorzystanie w zarządzaniu procesami organizacji. Zidentyfikowano również czynniki wpływające na to, że organizacje decydują się na zlecanie procesów na zewnątrz. Przedstawiono również aktualne metody oceny skuteczności procesów. W rozdziale drugim przedstawiono charakterystykę podmiotu badań oraz wnioski z przeglądu literatury dotyczącej outsourcingu w podmiotach leczniczych w Polsce i za granicą. Zaprezentowano również i poddano krytycznej analizie istniejące już modele oceny skuteczności outsourcingu oraz odpowiednie uwarunkowania prawne i normatywne. W rozdziale trzecim opisano zastosowaną metodykę badań, w tym hipotezy sformułowane na podstawie studium literatury przedmiotu. Zawarto tu też wyniki badań ilościowych oraz jakościowych, które posłużyły do weryfikacji hipotez. Przedstawione zostały procesy zlecane na zewnątrz przez badane podmioty wraz z czynnikami warunkującymi skuteczność tych procesów. Przedstawiono również arkusz oceny dostawcy outsourcingowego, który jest wynikiem nawiązującym do celu utylitarnego niniejszej pracy. W podsumowaniu zawarto ujęte syntetycznie rezultaty przeprowadzonych badań, wnioski i rekomendacje oraz ograniczenia dotyczące wyników tej pracy.
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Oversizing the photovoltaic generator capacity in a micro photovoltaic plant
- Zbigniew Lubośny
A significant part of photovoltaic micro installations in Poland is characterized by photovoltaic generator oversizing in relation to the inverter. The idea of oversizing, however, still raises doubts among some plant owners. In the paper, the energy yield of installation with an oversized and not oversized photovoltaic generator is presented on selected examples, showing the legitimacy of oversizing.
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Overview of the three multicriteria approaches applied to a global assessment of analytical methods
- Paweł Mateusz Nowak
- Paweł Kościelniak
- Marek Tobiszewski
- Ana Ballester-Caudet
- Pilar Campíns-Falcó
Critical and global evaluation of analytical methods should be one of the primary goals in analytical chemistry. A holistic approach, however, requires a look at the varied features: commonly discussed validation criteria, often underrated practical and economic aspects, and typically overlooked compliance with the principles of green analytical chemistry. Carrying out such an assessment in a critical and transparent way is extremely difficult without special tools. The purpose of this work is to discuss and compare the three different approaches that seem to be potential candidates: multi-criteria decision analysis methods (MCDA), HEXAGON, and RGB model. The basic principles of each methodology, individual possibilities offered, and the results of the assessment of selected model methods will be presented. Ultimately, the potential compatibility of assessing the same group of methods using different tools will be examined. This contribution can help to select optimal tool and conduct more thorough and insightful assessments.