Applied sciences

Bulletin of the Polish Academy of Sciences: Technical Sciences

Content

Bulletin of the Polish Academy of Sciences: Technical Sciences | 2022 | 70 | 4

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Abstract

As nonlinear optimization techniques are computationally expensive, their usage in the real-time era is constrained. So this is the main challenge for researchers to develop a fast algorithm that is used in real-time computations. This work proposes a fast nonlinear model predictive control approach based on particle swarm optimization for nonlinear optimization with constraints. The suggested algorithm divide and conquer technique improves computing speed and disturbance rejection capability, demonstrating its suitability for real-time applications. The performance of this approach under constraints is validated using a highly nonlinear fast and dynamic real-time inverted pendulum system. The solution presented through work is computationally feasible for smaller sampling times and it gives promising results compared to the state of art PSO algorithm
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Authors and Affiliations

Supriya P. Diwan
1
Shraddha S. Deshpande
2

  1. Government College of Engineering, Karad-415124, Maharashtra, India
  2. Walchand College of Engineering, Sangli-416415, Maharashtra, India
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Abstract

The article discusses an example of the use of graph search algorithms with trace of water analysis and aggregation of failures in the occurrence of a large number of failures in the Water Supply System (WSS). In the event of a catastrophic situation, based on the Water Distribution System (WDS) network model, information about detected failures, the condition and location of valves, the number of repair teams, criticality analysis, the coefficient of prioritization of individual network elements, and selected objective function, the algorithm proposes the order of repairing the failures should be analyzed. The approach proposed by the authors of the article assumes the selection of the following objective function: minimizing the time of lack of access to drinking water (with or without prioritization) and minimizing failure repair time (with or without failure aggregation). The algorithm was tested on three different water networks (small, medium, and large numbers of nodes) and three different scenarios (different numbers of failures and valves in the water network) for each selected water network. The results were compared to a valve designation approach for closure using an adjacency matrix and a Strategic Valve Management Model (SVMM).
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Authors and Affiliations

Ariel Antonowicz
1
ORCID: ORCID
Andrzej Urbaniak
1

  1. Institute of Computing Science, Poznan University of Technology, ul. Piotrowo 2, 60-965 Poznan, Poland
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Abstract

This issue is a typical NP-hard problem for an unrelated parallel machine scheduling problem with makespan minimization as the goal and no sequence-related preparation time. Based on the idea of tabu search (TS), this paper improves the iterative greedy algorithm (IG) and proposes an IG-TS algorithm with deconstruction, reconstruction, and neighborhood search operations as the main optimization process. This algorithm has the characteristics of the strong capability of global search and fast speed of convergence. The warp knitting workshop scheduling problem in the textile industry, which has the complex characteristics of a large scale, nonlinearity, uncertainty, and strong coupling, is a typical unrelated parallel machine scheduling problem. The IG-TS algorithm is applied to solve it, and three commonly used scheduling algorithms are set as a comparison, namely the GA-TS algorithm, ABC-TS algorithm, and PSO-TS algorithm. The outcome shows that the scheduling results of the IG-TS algorithm have the shortest manufacturing time and good robustness. In addition, the production comparison between the IG-TS algorithm scheduling scheme and the artificial experience scheduling scheme for the small-scale example problem shows that the IG-TS algorithm scheduling is slightly superior to the artificial experience scheduling in both planning and actual production. Experiments show that the IG-TS algorithm is feasible in warp knitting workshop scheduling problems, effectively realizing the reduction of energy and the increase in efficiency of a digital workshop in the textile industry.
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Authors and Affiliations

Xinfu Chi
1
ORCID: ORCID
Shijing Liu
1
Ce Li
1

  1. Dong Hua University, College of Mechanical Engineering, Shanghai 201620, China
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Abstract

In this paper, a model of an electromagnetic system with two levitating magnets is presented. Modeling was performed using the results of experiments. The data obtained make it possible to fit the magnetic forces between two magnets using a 5th order polynomial. The time series show that dry friction constitutes an important part of damping forces. The differential equations of motion consider strong nonlinearities of magnetic and damping forces. These terms cause the nonlinear hardening effect. The energy recovered by magnetic induction is dissipated in the resistors. Numerical simulations show that resistance has an impact on magnet dynamics and energy recovery. From the resonance characteristics obtained, optimal resistance is determined when energy recovery is the highest.
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Authors and Affiliations

Andrzej Mitura
1
ORCID: ORCID
Krzysztof Kecik
1
ORCID: ORCID

  1. Faculty of Mechanical Engineering, Department of Applied Mechanics, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin, Poland
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Abstract

The underframe passive inerter-based suspended device, based on the inerter-spring-damper vibration attenuation structure, could improve the dynamic performance of the train body, but its parameters are fixed and cannot meet the dynamic performance requirements under different operating conditions. Therefore, a semi-active inerter-based suspended device based on the linear quadratic regulator (LQR) control strategy is proposed to further enhance the dynamic performance. The rigid-flexible coupling vertical dynamic model of the train body and an underframe semi-active inerter-based suspended device are established. The structural parameters of the semi-active inerter-based suspended device are adjusted using LQR control strategy. Dynamic response of the system is obtained using the virtual excitation method. The dynamic characteristic of the system is evaluated using the Sperling index and compared with those of the passive and semi-active traditional suspended devices as well as the passive inerter-based suspended devices. The vertical vibration acceleration of the train body and Sperling index using the semi-active inerter-based suspended device is the smallest among the four suspended devices, which denotes the advantages of using the inerter and LQR control strategy. The semi-active inerter-based suspended device could decrease the vertical vibration acceleration of the train body and further suppress its elastic vibration in the lower frequency band, more effectively than the other three suspended devices. Overall, the semi-active inerter-based suspended device could significantly reduce elastic vibration of the train body and improve its dynamical performance.
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Authors and Affiliations

Yong Wang
1 2
ORCID: ORCID
Hao-Xuan Li
2
Hao-Dong Meng
3
Yang Wang
1

  1. State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130022, China
  2. Automotive Engineering Research Institute, Jiangsu University, Zhenjiang 212013, China
  3. School of Automotive Engineering, Changzhou Institute of Technology, Changzhou 213002, China
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Abstract

The performance of a novel airfoil-based tube with dimples is numerically studied in the present work. The effect of Reynolds number Re, dimples number N, relative depth H/D, and cross-distribution angle α on flow and heat transfer characteristics are discussed for Re in the range between 7,753 and 21,736. The velocity contour, temperature contour, and local streamlines are also presented to get an insight into the heat transfer enhancement mechanisms. The results show that both the velocity magnitude and flow direction change, and fluid dynamic vortexes are generated around the dimples, which intensify the flow mixing and interrupt the boundary layer, resulting in a better heat transfer performance accompanied by a certain pressure loss compared with the plain tube. The Nusselt number Nu of the airfoil-based tube increases with the increase of dimples number, relative depth, and Reynolds numbers, but the effect of cross-distribution angle can be ignored. Under geometric parameters considered, the airfoil-based tube with N = 6, H/D = 0.1, α = 0° and Re = 7,753 can obtain the largest average PEC value 1.23. Further, the empirical formulas for Nusselt number Nu and friction factor f are fitted in terms of dimple number N, relative depth H/D, and Reynolds number Re, respectively, with the errors within ± 5%. It is found that the airfoil-based tube with dimples has a good comprehensive performance.
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Authors and Affiliations

Houju Pei
1
ORCID: ORCID
Meinan Liu
2
Kaijie Yang
3
Li Zhimao
1
Chao Liu
1

  1. Shanghai Aircraft Design and Research Institute Environment Control and Oxygen System Department, China
  2. College of Energy and Power Engineering, Jiangsu University of Science and Technology, China
  3. Key Laboratory of Aircraft Environment Control and Life Support, MIIT, Nanjing University of Aeronautics and Astronautics, China
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Abstract

Low-Density Parity-Check (LDPC) codes are among the most effective modern error-correcting codes due to their excellent correction performance and highly parallel decoding scheme. Moreover, the nonbinary extension of such codes further increases performance in the short-block regime. In this paper, we review the key elements for the construction of implementation-oriented binary and nonbinary codes. These Quasi-Cyclic LDPC (QC-LDPC) codes additionally feature efficient encoder and decoder implementation frameworks. We then present a versatile algorithm for the construction of both binary and nonbinary QC-LDPC codes that have low encoding complexity and an optimized corresponding graph structure. Our algorithm uses a progressive edge growth algorithm, modified for QC-LDPC graph construction, and then performs an iterative global search for optimized cyclic shift values within the QC-LDPC circulants. Strong error correction performance is achieved by minimizing the number of short cycles, and cycles with low external connectivity, within the code graph. We validate this approach via error rate simulations of a transmission system model featuring an LDPC coder-decoder, digital modulation, and additive white Gaussian noise channels. The obtained numerical results validate the effectiveness of the proposed construction algorithm, with a number of constructed codes exhibiting either similar or superior performance to industry standard binary codes and selected nonbinary codes from the literature.
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Authors and Affiliations

Wojciech Sułek
1
ORCID: ORCID

  1. Silesian University of Technology, Gliwice, Poland
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Abstract

The article proposes a model in which Diffusion Approximation is used to analyse the TCP/AQM transmission mechanism in a multinode computer network. In order to prevent traffic congestion, routers implement AQM (Active Queue Management) algorithms. We investigate the influence of using RED-based AQM mechanisms and the fractional controller PIγ on the transport layer. Additionally, we examine the cases in which the TCP and the UDP flows occur and analyse their mutual influence. Both transport protocols used are independent and work simultaneously. We compare our solution with the Fluid Flow approximation, demonstrating the advantages of Diffusion Approximation.
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Authors and Affiliations

Dariusz Marek
1
ORCID: ORCID
Adam Domański
1
ORCID: ORCID
Joanna Domańska
2
ORCID: ORCID
Jakub Szyguła
1
ORCID: ORCID
Tadeusz Czachórski
2
ORCID: ORCID
Jerzy Klamka
2
ORCID: ORCID
Katarzyna Filus
2
ORCID: ORCID

  1. Faculty of Automatic Control, Electronics and Computer Science, Department of Distributed Systems and Informatic Devices, Silesian University of Technology, Akademicka 16, 44-100 Gliwice, Poland
  2. Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, Bałtycka 5, 44-100 Gliwice, Poland
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Abstract

The paper is related to the material behaviour of additively manufactured samples obtained by the direct metal laser sintering (DMLS) method from the AlSi10Mg powder. The specimens are subjected to a quasi-static and dynamic compressive loading in a wide range of strain rates and temperatures to investigate the influence of the manufacturing process conditions on the material mechanical properties. For completeness, an analysis of their deformed microstructure is also performed. The obtained results prove the complexity of the material behaviour; therefore, a phenomenological model based on the modified Johnson–Cook approach is proposed. The developed model describes the material behaviour with much better accuracy than the classical constitutive function. The resulted experimental testing and its modelling present the potential of the discussed material and the manufacturing technology.
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Authors and Affiliations

Magda Stanczak
1 2
ORCID: ORCID
Alexis Rusinek
2
ORCID: ORCID
Paula Broniszewska
3
ORCID: ORCID
Teresa Fras
1
ORCID: ORCID
Piotr Pawłowski
3
ORCID: ORCID

  1. Department of Protection Technologies, Security & Situational Awareness, French-German Research Institute of Saint-Louis (ISL), 68301 Saint-Louis, France
  2. Laboratory of Microstructure Studies and Mechanics of Materials (LEM3), Lorraine University, 57070 Metz, France
  3. Institute of Fundamental Technological Research (IPPT PAN), Polish Academy of Sciences, 02-106 Warsaw, Poland
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Abstract

The methods of severe plastic deformation (SPD) of metals and metal alloys are very attractive due to the possibility of refinement of the grains to nanometric sizes, which facilitates obtaining high mechanical properties. This study investigated the influence of SPD in the process of hydrostatic extrusion (HE) on the anisotropy of the mechanical properties of the CuCrZr copper alloy. The method of HE leads to the formation of a characteristic microstructure in deformed materials, which can determine their potential applications. On the longitudinal sections of the extruded bars, a strong morphological texture is observed, manifested by elongated grains in the direction of extrusion. In the transverse direction, these grains are visible as equiaxed. The anisotropy of properties was mainly determined based on the analysis of the static mini-sample static tensile test and the dynamic impact test. The obtained results were correlated with microstructural observations. In the study, three different degrees of deformation were applied at the level necessary to refine the grain size to the ultrafine-grained level. Regardless of the applied degree of deformation, the effect of the formation of a strong morphological texture was demonstrated, as a result of which there is a clear difference between the mechanical properties depending on the test direction, both by the static and dynamic method. The obtained results allow for the identification of the characteristic structure formed during the HE process and the more effective use of the CuCrZr copper alloy in applications.
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Authors and Affiliations

Sylwia Przybysz
1
Mariusz Kulczyk
1
ORCID: ORCID
Jacek Skiba
1
Monika Skorupska
1

  1. Institute of High Pressure Physics of the Polish Academy of Sciences, Warszawa, Poland
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Abstract

In this paper, the performance of the Bayesian Optimization (BO) technique applied to various problems of microwave engineering is studied. Bayesian optimization is a novel, non-deterministic, global optimization scheme that uses machine learning to solve complex optimization problems. However, each new optimization scheme needs to be evaluated to find its best application niche, as there is no universal technique that suits all problems. Here, BO was applied to different types of microwave and antenna engineering problems, including matching circuit design, multiband antenna and antenna array design, or microwave filter design. Since each of the presented problems has a different nature and characteristics such as different scales (i.e. number of design variables), we try to address the question about the generality of BO and identify the problem areas for which the technique is or is not recommended.
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Authors and Affiliations

Michal Baranowski
1
ORCID: ORCID
Grzegorz Fotyga
1
ORCID: ORCID
Adam Lamecki
1 2
ORCID: ORCID
Michal Mrozowski
1
ORCID: ORCID

  1. Gdańsk University of Technology, Gdańsk, Gabriela Narutowicza 11/12 80-233, Poland
  2. EM Invent Sp. z o.o., Gdańsk, Trzy Lipy 3 80-172, Poland
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Abstract

This paper presents a novel method to overcome problems of finite set-model-based predictive torque control (MPTC) which has received a lot of attention in the last two decades. Tuning the weighting factor, evaluating a large number of switching states in the loop of the predictive control, and determining the duty cycle are three major challenges of the regular techniques. Torque and flux responses of deadbeat control have been developed to overcome these problems. In our method, firstly, the prediction stage is performed just once. Then, both the weighted cost function and its evaluation are replaced with only simple relationships. The relationships reduce torque ripple and THD of stator current compromisingly. In the next step, the length of the virtual vector is used to determine the duty cycle of the optimum voltage vector without any additional computations. The duty ratio does not focus on any relation or criteria minimizing torque or flux ripple. As a result, torque and flux ripples are reduced equally. The proposed duty cycle is calculated by using a predicted virtual voltage vector. Hence, no new computation is needed to determine the proposed duty cycle. Simulation and experimental results confirm both the steady and dynamic performance of the proposed method in all speed ranges.
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Authors and Affiliations

Babak Kiani
1

  1. Department of Electrical Engineering, Izeh Branch, Islamic Azad University, Izeh, Iran
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Abstract

Large sets of articles are evaluated by predefined measures such as the article numbers and h-indexes. All of these indicators are scalars and refer rather to one discipline or the comprehensive science. Thus, according to disciplinary categories in scientific databases, the distribution has become too rigid for current science needs, dynamically growing towards inter- and trans-disciplinarity. We propose a new method of calculating the impact on knowledge of articles and their citations, creating citation networks, and using one of the optimistic fuzzy aggregation norms to estimate the contribution to the knowledge considering the citation inheritance of citing papers to cited papers (paper children to the paper-parents). Due to this method, we produced the contribution vectors for various disciplines/subdisciplines based on articles and their citations of publications belonging to the considered disciplines. We can prepare the scientific profiles of papers and disciplines based on the contribution vectors. Moreover, we can evaluate how much citations matter in the development of science. Applying this method, we can estimate the contribution to the considered research field caused by papers and their citations from different areas of science. The proposed method might be applicable in the assessment of developing concepts.
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Authors and Affiliations

Aleksandra Mreła
1
ORCID: ORCID
Veslava Osińska
2
ORCID: ORCID
Oleksandr Sokolov
3
ORCID: ORCID

  1. Institute of Informatics, Kazimierz Wielki University in Bydgoszcz, Kopernika 1, 85-074 Bydgoszcz, Poland
  2. Institute of Information and Communication Research, Nicolaus Copernicus University in Torun, W. Bojarskiego 1, 87-100 Torun, Poland
  3. Department of Informatics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in TorunDepartment of Informatics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń
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Abstract

Evaluating soil strength by geophysical methods using P-waves was undertaken in this study to assess the effects of changed binder ratios on stabilization and compression characteristics. The materials included dredged sediments collected in the seabed of Timrå region, north Sweden. The Portland cement (Basement CEM II/A-V, SS EN 197-1) and ground granulated blast furnace slag (GGBFS) were used as stabilizers. The experiments were performed on behalf of the Svenska Cellulosa Aktiebolaget (SCA) Biorefinery Östrand AB pulp mill. Quantity of binder included 150, 120 and 100 kg. The properties of soil were evaluated after 28, 42, 43, 70, 71 and 85 days of curing using applied geophysical methods of measuring the travel time of primary wave propagation. The P-waves were determined to evaluate the strength of stabilized soils. The results demonstrated variation of P-waves velocity depending on stabilizing agent and curing time in various ratios: Low water/High binder (LW/HB), High water/Low binder (HW/LB) and percentage of agents (CEM II/A-V/GGBFS) as 30%/70%, 50%/50% and 70%/30%. The compression characteristics of soils were assessed using uniaxial compressive strength (UCS). The P-wave velocities were higher for samples stabilized with LW/HB compared to those with HW/LB. The primary wave propagation increased over curing time for all stabilized mixes along with the increased UCS, which proves a tight correlation with the increased strength of soil solidified by the agents. Increased water ratio gives a lower strength by maintained amount of binder and vice versa.

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Authors and Affiliations

Per Lindh
1 2
ORCID: ORCID
Polina Lemenkova
3
ORCID: ORCID

  1. Swedish Transport Administration, Gibraltargatan 7, Malmö, Sweden
  2. Lund University, Division of Building Materials, Box 118, SE- 221-00, Lund, Sweden
  3. Université Libre de Bruxelles (ULB), École polytechnique de Bruxelles (Brussels Faculty of Engineering), Laboratory of Image Synthesis and Analysis (LISA). Campus de Solbosch - CP 165/57, Avenue Franklin D. Roosevelt 50, B-1050 Brussels, Belgium

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