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1

Model of the random phase of signal E6 of the Galileo Satellite Navigation System

Džunda M., Čikovský S., Melniková L.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

61--68

EN

The aim of this paper was to describe the random phase of the E6 signal, the Galileo satellite navigation system. Based on the available information, mathematical models of the measurement signals of the Galileo system were created. The frequencies of individual signals were determined and their structure visualized. A block diagram of the generation of individual signals is also shown. The main contribution of the paper is the creation of a random phase model of the E6 signal from the Galileo system. In accordance with the technical data of the Galileo system, the parameters of the random phase model were determined. The simulation results confirmed that the frequency instability of the continuous signal E6 n received from the satellite is a stationary process. The short-term stability of the frequency ranges from 10-13 to 10-14. The simulation results confirmed that the Doppler effect significantly affects the random phase of the E6 signal. This phenomenon can affect the results of navigation measurements using the E6 signal. The modeling and simulation results of the random phase of the E6 signal presented in the paper can be used to evaluate the immunity of the Galileo navigation system to interference.

2

Modeling and simulation of the furniture manufacturing and assembly process in the Arena simulation software

Kolny Damian, Kaczmar-Kolny Ewa, Dulina Ľuboslav

Technologia i Automatyzacja Montażu

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2023

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nr 1

13--22

EN

The article describes issues related to creating discrete simulation models for the implementation of the furniture manufacturing and assembly process in a furniture company. The methodology of the manufacturing system analysis was presented, which is aimed to support the appropriate approach to the construction of simulation models. The scope of the work includes the technological identification of the furniture manufacturing and assembly process in real production conditions, on the basis of which the appropriate simulation model was built. The course of the process was analyzed in the Arena software on the basis of a computer simulation based on reports. As a result of the simulation of the manufacturing process with the use of information from report of usage, an area for improvement was located. The re-analysis of the material flow made it possible to propose a change in the input parameters for the simulation model in the indicated area. The results of the second simulation show significant changes in the effective use of workstations and increase in the efficiency of the production line. In practice, it can be the basis for introducing simulated changes in the production system.

PL

W artykule opisano zagadnienia związane z tworzeniem dyskretnych modeli symulacyjnych dla realizacji procesu wytwarzania i montażu mebli w przedsiębiorstwie branży meblarskiej. Przedstawiono metodykę analizy systemu wytwarzania, która ma za zadanie wspierać właściwe podejście dla budowy modeli symulacyjnych. Zakresem praca obejmuje identyfikację technologiczną procesu wytwarzania i montażu mebli w rzeczywistych warunkach produkcyjnych, w oparciu o którą zbudowano właściwy model symulacyjny na przykładzie procesu wytwarzania w rzeczywistych warunkach produkcyjnych. Analizę przebiegu procesu na podstawie symulacji komputerowej w oparciu o raporty przeprowadzono w oprogramowaniu Arena. W wyniku przeprowadzonej symulacji procesu wytwarzania z wykorzystaniem informacji z raportu obciążeń stanowiskowych zlokalizowano obszar do doskonalenia. Powtórna analiza przepływu materiałowego pozwoliła zaproponować zmianę parametrów wejściowych dla modelu symulacyjnego we wskazanym obszarze. Wyniki drugiej symulacji wskazują istotne zmiany w zakresie efektywnego wykorzystania stanowisk pracy oraz zwiększenia wydajności linii produkcyjnej. W praktyce może to stanowić podstawę do wprowadzenia symulowanych zmian w omawianym systemie produkcyjnym.

3

Techniczno-ekonomiczna analiza produkcji wodoru z biogazu w instalacji przemysłowej

Wodołażski Artur

Przemysł Chemiczny

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2023

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T. 102, nr 6

572--576

PL

Przedstawiono techniczno-ekonomiczną analizę produkcji wodoru z biogazu przez parowy reforming biometanu. Kompleksowa analiza obejmuje bilans masowo-energetyczny instalacji, analizę finansową oraz ekologiczną. Poddano ocenie potencjał utylizacji odpadów (obornika) w kierunku przetworzenia na wodór poprzez reforming parowy biometanu. Wyniki przeprowadzonej analizy pokazują atrakcyjny sposób produkcji biowodoru z biogazu jako ekonomiczną technologię przetwarzania odpadów połączoną z ograniczeniem emisji zanieczyszczeń powodujących efekt cieplarniany.

EN

A numerical model of a pilot plant producing H₂ from biogas by steam reforming of biomethane was developed using Chemcad. The anal. covered the mass and energy balance of the installation, as well as financial and ecological estimation. The results of the anal. showed that the method of H₂ production is economical and reduces pollutant emissions.

4

Impact of residual doping on surface current of InGaAs/InP photodiode passivated with regrown InP

Braga Osvaldo M., Delfino Cristian A., Kawabata Rudy M. S., Pinto Luciana D., Vieira Gustavo S., Pires Mauricio P., Souza Patricia L., Marega Euclydes, Carlin John A., Krishna Sanjay

Opto-Electronics Review

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2023

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Vol. 31, Special Issue

art. no. e144562

EN

The viability of epitaxial regrowth of non-intentionally doped InP to passivate lateral mesa surfaces of InGaAs photodiodes lattice-matched to InP is investigated, evaluating whether the residual doping of the regrown layer can be responsible for un unexpected increase of the surface current. The effect of residual doping is evaluated via numerical calculations of dark current, considering the range of doping concentrations expected for non-intentionally doped InP. The calculations show that the increase in dark current due to the residual doping of the regrown InP layer is not enough to justify the observed increase in surface current. On the other hand, the technique is still valid as a passivation method if the photodetector pixel is isolated by etching only the top contact layer.

5

Deep learning classification and recognition method for milling surface roughness combined with simulation data

Lu Lingli, Yi Huaian, Shu Aihua, Qin Jianhua, Lu Enhui

Metrology and Measurement Systems

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2023

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Vol. 30, nr 1

117--138

EN

To address the problem that a deep neural network needs a sufficient number of training samples to have a good prediction performance, this paper firstly used the Z-Map algorithm to generate a simulated profile of the milling surface and construct an optical simulation model of surface imaging to supplement the training sample size of the neural network. Then the Deep CORAL model was used to match the textures of the simulated samples and the actual samples across domains to solve the problem that the simulated samples were not in the same domain as the actual milling samples. Experimental results have shown that high texture matching could be achieved between optical simulation images and actual images, laying the foundation for expanding the actual milled workpiece images with the simulation images. The deep convolutional neural model Xception was used to predict the classification of six classes of data sets with the inclusion of simulation images, and the accuracy was improved from 86.48% to 92.79% compared with the model without the inclusion of simulation images. The proposed method solves the problem of the need for a large number of samples for deep neural networks and lays the foundation for similar methods to predict surface roughness for different machining processes.

6

Case Study: Testing the Overall Efficiency of Equipment in the Production Process in TX Plant Simulation Software

Pekarčíková Miriam, Trebuna Peter, Kliment Marek, Trojan Jozef, Kopec Ján, Dic Michal, Kronová Jana

Management and Production Engineering Review

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2023

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Vol. 14, No. 1

34--42

EN

The article deals with a widely used method of measuring the overall efficiency of equipment (OEE), which in combination with technologies and software tools is gaining in importance. The overall efficiency of OEE equipment is a key performance metric for machines and equipment to identify hidden capacities and increase production productivity. The intensification of Industry 4.0 in traditional manufacturing companies supports and creates the conditions for their transformation into a smart factory. The integration of intelligent machines and devices with complex human-machine communication network systems requires a new direction in measuring and increasing OEE. Mass customization, resp. personalization of production raises a high need to monitor, improve and further maintain productivity. The aim of the article is to create a simulation model of the production process and test the energy consumption of selected equipment using TX Plant Simulation software with a proposal of measures to increase the OEE of the company.

7

Evaluation and Analysis of the Implementation Process of the Use of Rail Transport in Military Transport Using Flexsim Software

Pawlisiak Mieczysław, Smalcuga Katarzyna, Waśniewski Tomasz

Logistics and Transport

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2023

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Vol. 57-58, No. 1-2

115--130

EN

In the realities of modern battlefield, training of soldiers is crucial, therefore it is so important to develop an optimal concept of moving troops by rail transport, for exercises and training in peacetime. Using the simulation of the implementation of rail and road transport, it is possible to analyse and meet the needs of the selected relationship of individual stages of the process studied. Simulation model allows to state that it serves as an illustrative, training element and an element showing some results with changeable situations, therefore it can be a solution for training and making critical decisions for competent commanders.

8

Fuel flow test through a leaky fuel assembly

Ułanowicz Leszek, Jastrzębski Grzegorz, Tomaszek Łukasz, Szczepaniak Paweł

Journal of KONBiN

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2023

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Vol. 53, iss. 1

109--136

EN

The occurrence of an external leak in the aviation fuel unit leads to a catastrophic aviation event. The aim of the research was to estimate the flow of the fuel stream through the fuel filter chamber with its external unsealing. The research was carried out using experimental methods and computer CFD modelling. Experimental studies were carried out on a specially designed test stand. During the tests, the flow rate of the fuel stream flowing out to the environment was changed. Numerical calculations allowed to obtain the values of the stream and pressure inside the leaky filter chamber. The results of numerical calculations were compared with the results of experimental measurements. The CFD method significantly supplemented the information on the fuel flow inside the considered filter chamber at its external unsealing. The use of software based on the CFD method allows to obtain reliable values characterizing the fuel flow in the aviation fuel unit.

PL

Wystąpienie nieszczelności zewnętrznej w lotniczym zespole paliwowym prowadzi do katastroficznego zdarzenia lotniczego. Celem badań było oszacowanie przepływu strugi paliwa przez komorę filtra paliwowego, przy jego zewnętrznym rozszczelnieniu. Badania wykonano metodami eksperymentalnymi oraz z użyciem komputerowego modelowania CFD. Badania eksperymentalne przeprowadzono na specjalnie zaprojektowanym stanowisku badawczym. W czasie badań zmieniano natężenie przepływu strugi paliwa wypływającej do otoczenia. Obliczenia numeryczne pozwoliły uzyskać wartości strumienia i ciśnienia wewnątrz nieszczelnej komory filtra. Wyniki obliczeń numerycznych zostały porównane z wynikami pomiarów eksperymentalnych. Metoda CFD w znacznym stopniu uzupełniła informacje o przepływie paliwa wewnątrz rozpatrywanej komory filtra przy jego zewnętrznym rozszczelnieniu. Wykorzystanie oprogramowania bazującego na metodzie CFD pozwala uzyskać wiarygodne wartości charakteryzujące przepływ paliwa w lotniczym zespole paliwowym.

9

A Dual-Band Compact Integrated Rectenna for Implantable Medical Devices

Hussein Shamil H., Mohammed Khalid K.

International Journal of Electronics and Telecommunications

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2023

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Vol. 69, No. 2

239--245

EN

This work describes a dual band compact fully integrated rectenna circuit for implantable medical devices (IMDs). The implantable rectenna circuit consists of tunnel diode 10×10μm2 QW-ASPAT (Quantum Well Asymmetric Spacer Tunnel Layer diode) was used as the RF-DC rectifier due to its temperature insensitivity and nonlinearity compared with conventional SBD diode. SILVACO atlas software is used to design and simulate 100μm2 QW InGaAs ASPAT diode. A miniaturized dual band implantable folded dipole antenna with multiple L-shaped conducting sections is designed using CST microwave suits for operation in the WMTS band is 1.5GHz and ISM band of 5.8GHz. High dielectric constant material Gallium Arsenide (εr=12.94) and folded geometry helps to design compact antennas with a small footprint of 2.84mm3 (1×4.5×0.63) mm3. Four-layer human tissue model was used, where the antenna was implanted in the skin model at depth of 2mm. The 10-dB impedance bandwidth of the proposed compact antenna at 1.5GHz and 5.8GHz are 227MHz (1.4-1.63GHz) with S11 is -22.6dB and 540MHz (5.47-6.02GHz) with S11 is -23.1dB, whereas gains are -36.9dBi, and -24.3dBi, respectively. The output DC voltage and power of the rectenna using two stage voltage doubler rectifier (VDR) are twice that produced by the single stage at input RF power of 10dBm.

10

Camouflage Assessments with Digital Pattern Painting Based on the Multi-Scale Pattern-in-Picture Evaluation Model

Jia Qi, Xu Weidong, Yi Yang, Liu Jun, Hu Jianghua, Zhu Liyan, Yang Xin

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 2

39--50

EN

In general, traditional evaluations of target camouflage effects are usually conducted based on observational data and general results of statistical analysis. This widely applied methodology quantifies the detection and identification probabilities of camouflage objects but has considerable shortcomings. This data evaluation process is laborious and time-consuming and very low in reproducibility, which sheds light on the necessity of developing a more efficient method in this study field. The growth of computeraided image processing technology provides technical support for camouflage effect evaluation based on digital image processing. Digital pattern painting, which has been previously applied to combat utility uniforms, is a new methodology full of potential due to its broad geographical adaptability. This study proposes a multi-scale pattern-in-picture method to evaluate camouflage effects at different distances. We also established a computer-aided background image library and camouflage assessments with digital simulation and created an evaluation system that could be effectively applied to combat utility uniforms. More than 40 testers participated in this study, who were asked to score the designed camouflage schemes using the evaluation system proposed. The data from simulation assessments and individual evaluations show that the computer-aided simulation assessments conducted as part of this research can efficiently and objectively evaluate the camouflage effect on military objects.

11

Novel rheological modelling of thermosets and unidirectional monotropic fibre-reinforced thermoset matrix composites

Klasztorny Marian, Nycz Daniel B.

Composites Theory and Practice

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2023

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R. 23, nr 1

3--21

EN

A refined, fully analytical rheological modelling of thermosetting polymers and unidirectional monotropic fibre-reinforced thermoset matrix (UFRT) composites is presented. New polymers and composites under normal conditions, fully relaxed from curing and post-curing stresses, are modelled. The theory includes quasi-static short-term/medium-term/long-term reversible rheological processes. Thermosets are isotropic materials exhibiting linearly viscoelastic shear strains and linearly elastic bulk strains. Fibres are monotropic (transversely isotropic) and linearly elastic materials. A generic function well reproducing the viscoelastic characteristics of thermosets and UFRT composites is a Mittag-Leffler fractional exponential function in an integral form. Coupled/uncoupled standard/inverse constitutive equations of linear rheology are formulated for thermosets and UFRT composites. The equations are mutually analytically transformable. New rheological models (coded H-R/H) for thermosets and UFRT composites are described by the smallest possible number of material constants. The thermoset is described by two independent elastic constants and three independent viscoelastic constants. The homogenized UFRT composite is described by five independent elastic constants and four independent viscoelastic constants, whereby two visco-elastic constants are common to the matrix and the composite. An improved homogenization theory of UFRT composites, based on analytical solutions of the selected tasks of the theory of linear elasticity, is formulated for monotropic fibres and positively validated experimentally. The viscoelastic constants of the thermoset are calculated analytically in an iterative loop using a long-term unidirectional tension creep experimental test. The viscoelastic constants of the UFRT composite are calculated analytically employing H-R/H shear/quasi-shear storage compliances and VECP (the viscoelastic-elastic correspondence principle) shear/quasi-shear storage compliances. The H-R/H rheological model was validated numerically for selected UFRT composites. The validation tests were performed on the enhanced reliability UFRT composites reported by Soden, Hinton, and Kaddour (Composites Science and Technology, 1998, 2002).

12

Augmented and Virtual Realities: the Future of Building Design and Visualization

Solanki DivyarajSinh M., Laddha Hrushikesh, Kangda Muhammed Zain, Noroozinejad Farsangi Ehsan

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 1

17--38

EN

The present study precisely conveys the methodology of developing a three-dimensional (3D) architectural model of a villa with its walk-through and displaying the model in virtual reality, which as a result, be used by the clients to spectate, customize and buy the real estate property. Additionally, the case study highlights the advancement in architecture, as certain specifications of each element of a 3D model can be viewed in a virtual environment. Virtual reality is a transpiring platform, and in addition to that, the real-estate sector shows its incorporation in designing, marketing, and selling projects. The teaching and learning process can be eased out by intervening it with technology that generates an enhanced visualization environment. These technologies, when used constructively, save time and energy and also hoard economic standards ensuing lucrative benefits.

13

Case hardening development review (2001-2020)

Wołowiec-Korecka E.

Archives of Materials Science and Engineering

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2023

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Vol. 120, nr 2

70--85

EN

Purpose: The purpose of the work is a complex review of methods applied industrially as case hardening. The paper contains an overview of scientific and development works on surface case hardening methods, especially carburising and quenching, described in the literature from 2001-2020. Design/methodology/approach: State-of-the-art was reviewed by a critical review of the world literature published in 2001-2022, including theoretical work, scientific research, and industry reports. An additional examination of the state of the art was conducted in terms of patent works. Findings: The period of 2001-2020 was a time of intensive work on the modernisation of case hardening techniques to improve the repeatability and uniformity of the produced layers and minimise deformations after hardening. Developing computing technologies have played a large part in this progress. New technologies have also been developed. Research limitations/implications: The review of papers and patent databases was limited to databases providing English-language content options. Practical implications: Case hardening is a crucial stage of steel heat treatment in almost every industrial branch: mechanical, tool, automotive, railway, and aviation. Originality/value: A synthetic review of case hardening methods was presented, particularly carburizing and quenching methods; it also analysed the possibilities and directions of their development.

14

The potential for real-time testing of high-frequency trading strategies through a developed tool during volatile market conditions

Vaitonis Mantas, Korovkinas Konstantinas

Applied Computer Science

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2023

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Vol. 19, no 2

63--81

EN

This study presents a method for testing high-frequency trading (HFT) for algorithms on GPUs using kernel parallelization, code vectorization, and multidimensional matrices. The research evaluates HFT strategies within algorithmic cryptocurrency trading in volatile market conditions, particularly during the COVID-19 pandemic. The study's objective is to provide an efficient and comprehensive approach to assessing the efficiency and profitability of HFT strategies. The results show that the method effectively evaluates the efficiency and profitability of HFT strategies, as demonstrated by the Sharp ratio of 2.29 and the Sortino ratio of 2.88. The authors suggest that further study on HFT testing methods could be conducted using a tool that directly connects to electronic marketplaces, enabling real-time receipt of high-frequency trading data and simulation of trade decisions. Finally, the study introduces a novel method for testing HFT algorithms on GPUs, offering promising results in assessing the efficiency and profitability of HFT strategies during volatile market conditions.

15

Temperature and Die Angular Effect on Tensile Strength, Hardness, Extrusion Load and Flow Stress in Aluminum 6063 Processed by Equal Channel Angular Extrusion Method

Azeez Temitayo M., Mudashiru Lateef O., Asafa Tesleem B., Akande Saheed, Ikumapayi Omolayo M., Kayode Joseph F., Uchegbu Ikenna D., Afolalu Sunday A.

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 1

346--353

EN

Developing aluminum with good mechanical properties like hardness, tensile strength, and normal flow stress, Equal Channel Angular Extrusion (ECAE) method has been suggested as a suitable metal forming process. The load applied and extrusion temperature normally infl uences the flow stress behavior in extruded products and de- termine their mechanical properties. Consequently, how these factors affect mechanical behavior and flow stress of Al 6063 processed by ECAE was examined in this study. Extrusion temperatures were 350°C, 425°C, and 500°C with die angles of 130°, 140°, and 150°. 5 mm/s of ram speed was applied. Each extrudate’s tensile strength and hardness were measured using a Universal Testing Machine and a Rockwell hardness tester. Samples with equal dimensions and properties were also modeled using the Qform software at the extended die angle and temperature for proper analysis of flow stress in the extrudates. According to experimental results, the temperature had a greater effect on the tensile strength and hardness of the billet than the die angle. The extrudates’ grains also became finer as the billet temperature rose. Simulation findings showed that higher billet temperature led to a decrease in the extrudates’ flow stress. The simulation also demonstrated that billet temperature had a greater impact on extrusion load than die angle, with a maximum extrusion load of 5.5 MN being attained at 350 °C.

16

Proposal of Workplace Modification in the Assembly Line in Automotive Production

Daneshjo Naqib, Mareš Albert, Malega Peter, Župčan Viktor

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

88--100

EN

This paper describes the application of computer simulation for the purpose of analysis of an assembly line and the subsequent proposal of changes to increase productivity. Tecnomatix Plant Simulation software was used for modeling, simulations, and analyses. Based on simulations and analyses of the original state, the bottlenecks of the line were identified, and improvement measures were proposed. The simulation model was adjusted, and the new state of the line was simulated. Based on the new simulation, it was proven that the proposed improvement would help in increasing the productivity of the assembly line. Computer simulation, in addition to verifying the production process itself, enables the optimal setting of the assembly line without interfering with the production itself.

17

Increasing the Efficiency of the Assembly Process Using the FMEA Method and Dynamic Simulation

Fedorko Gabriel, Neradilova Hana, Duriska Martin, Straka Kristian

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

249--256

EN

The efficiency of the assembly process is influenced by a wide range of different parameters. For their optimal setting, a thorough comprehensive analysis of the entire assembly process and identification of shortcomings in the form of bottlenecks or insufficient capacity utilization of assembly workplaces is necessary. As part of the presented paper, the use of the FMEA method in combination with dynamic simulation for analysis of the efficiency of its operation is presented on the example of a real assembly process. The obtained results showed the existence of a bottleneck in the supply area carried out by means of a single AGV set. The subsequent proposed solution, which consisted in the introduction of the use of another AGV set, brought an increase in the efficiency of individual assembly workplaces from the original values in the range of 75% to 85% to the level of 87% to 98%.

18

Design of a height-adjustable boarding system for a new double-deck railway vehicle

Šťastniak Pavol, Rakár Michal, Tížek Jakub

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 1

44--51

EN

This paper deals with a solution for faster and safer boarding and leaving of passengers at railway station platforms from 150 mm to 550 mm higher than the head of the rail. This conception is based on the requirements of railway infrastructure administrators, transporters and also manufacturers of passenger rolling stock. This device is designed for the new double-deck railway vehicle for suburban and regional transport, which fulfils legislative and normative requirements that are specified for the selected area of vehicle construction and operational features. Selected parts of the construction were verified through a series of simulation analyses. This article also includes a study that deals with optimization of the boarding area considering designed changes in the construction of the floor and a draft for modification of the vertical clearance of the boarding entrance area in a rough construction of the vehicle.

19

Joint frequency analysis of river flow rate and suspended sediment load using conditional density of copula functions

Sedighi Matina Pronoos, Ramezani Yousef, Tahroudi Mohammad Nazeri, Taghian Mehrdad

Acta Geophysica

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2023

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Vol. 71, no 1

489--501

EN

In this study, the river flow rate and suspended sediment load at Deh Molla hydrometric station in Zohreh River in the period of 1983–2018 were used for copula-based joint frequency. The Frank copula was selected as the best copula. The joint frequency analysis of the studied variables was performed based on the conditional density of the copula functions, which leads to the conditional occurrence probability of the variables. The results showed that with increasing river flow rate and suspended sediment load, the joint return period increases. Also, the joint return period for the "and" state is longer than the joint return period for the "or" state. When the river flow rate exceeds the threshold of 100 m3 /s and suspended sediment load exceeds the threshold of 2.7× 104 ton/day, the joint return periods for the "and" state and for the "or" state, are about 11 and 4 years, respectively.

20

Method of occupancy-based traffic light priority for public transport

Wiedemann Remigiusz

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 115

227--248

EN

This paper deals with the problem of urban traffic control, considering public transport as a priority. According to the authors, the occupancy of a means of transport is one of the key decision variables in the process of prioritisation within a traffic signal program. This study aims to construct a method of occupancy-based traffic light priority for public transport and investigate the possibility of using this information to increase the efficiency of signal control for time loss. The mathematical model of the priority level conditioning procedure proposed in the method was tested using a microsimulation model of the intersection. The simulation results were collated and compared with an approach that does not consider vehicle occupancy. Under given traffic conditions, the use of the proposed method allows for reducing the average time losses per person in the modelled road network.