Technical Transactions. Iss. 6

Technical Transactions. Iss. 6

Type: Collection of magazine numbers
Release date

Collection items (16)


The application of a simulation method in the evaluation of the reliability of transport systems

Kaczor, Grzegorz, Szkoda, Maciej
Article
2018
Reliability is the one of the key features that determine the probability of the proper functioning of a transport system. It refers to the degree to which the transported load is delivered on time, according to the client’s requirements. However, taking into account the complex relationships between the components of the transport system requires the application of appropriate methods of calculation. The paper presents the application of a method of reliability assessment, based on the Dynamic Fault Tree (DFT) and Monte Carlo (MC) simulation. The investigated approach may be used for the identification of weak components of the transport system and may form the basis for the improvement of reliability.

A simulation study of the graphical user interface of the head-up display and its influence on the driver’s perception

Skórska, Halszka, Sładek, Jerzy
Article
2018
This article presents the results of a simulation study of an augmented reality system and its influence on the user’s perception and reaction time. An automotive head-up display was chosen to conduct this research. It was assumed that the configuration of the GUI influences the perception and response time of the user of the augmented reality system. The perception of the driver was tested by using an eye-tracking device with accompanying software. The optimal graphical user interface (GUI) was developed as a result of the research.

Estimation of the localisation and geometric parameters of the semi-solid zone of steel samples

Dębiński, Tomasz
Article
2018
This paper presents the use of computer graphics methods for the initial estimation of the shape, position and volume of the semi-solid zone in samples from the Gleeble 3800 physical simulator. Simulations were performed for the verification of the heating and deformation process of steel with a semi-solid zone. The numerical model consists of three separate subsystems for describing the deformation of the solid and semi-solid zones: mechanical, thermal and predictive densities. Taking into consideration the specific localisation of these zones, the initial estimation of the location of the melting zone is very helpful in understanding the process and may be the starting point for further research. This article describes the technique of selecting areas in samples that meet the thermal criteria. This allows us to approximate the location and shape of the semi-solid zone and this information can be used at a later stage to further refine its parameters.

Relationship between the absolute error and parameter values of voltage output accelerometer

Tomczyk, Krzysztof, Sieja, Marek
Article
2018
The functional relationship between the absolute error and the parameter values of a voltage output accelerometer is presented in this paper. The theoretical basis for the mathematical model of the accelerometer and its standard, which is a reference for the error determination, is discussed. The polynomial function is applied for error approximation. Optimal orders of the polynomial along with their parameters and associated uncertainties are determined. The results presented in this paper concern the maximum errors obtained by exciting the accelerometer by the signal of constrained magnitude.

Active power measurement based on digital processing of voltage and current signals

Bień, Andrzej, Layer, Edward
Article
2018
The concept of active power measurement based on real-time digital processing of voltage and current signals is best’ introduced with a digital approximation definition. In this paper, the authors propose an integral calculation method based on Gregory’s expression, correction of integration period estimation and integration result correction taking values related to the ends of the integration period into account. In the described method, the integral is calculated between two consecutive maximums of the voltage and current product. Digital dependencies that are easy to implement are used for the evaluation of the active power value. To measure the voltage and current signals, the authors used a system with a digital signal processor and an A/D converter with a multiplexer followed by dedicated digital filters. The active power measurement method was checked by building an instrument simulation model.

Control of the vibration structure induced during works with the use of explosives

Sołtys, Anna, Pyra, Józef, Twardosz, Michał
Article
2018
This article presents the results of research on controlling the structure of vibrations induced during the firing of explosives with the use of non-electrical and electronic systems and the influence of the vibration structure during a transition from the ground to the building. The use of procedures associated with the selection of millisecond delay for firing explosive charges during blasting allows to get the excitation of favourable structure vibrations, thanks to a strong damping which is obtained at the transition from the ground to the structure. This means that optimally designed blasting works do not have to limit the mass of the explosives in the borehole as well as their number.

The impact of long-term travel demand changes on mixed decision problems of mass transit lines construction and vehicles’ depots location

Sawicki, Piotr, Fierek, Szymon
Article
2018
The paper is concentrated on solving a mixed decision problem of mass transit line construction and vehicles’ depots location (MTLC&VDL). The authors have iteratively solved this problem as a function of scenariobased, long-term travel demand changes, and finally have analysed the generated results. As a product of the computations, it has been proved that the solution of the mixed MTLC&VDL decision problem depends on changes in travel demand, both in terms of the line construction and the location of the depot. 5 and 10% increase of travel demand leads to changes in the optimal mass transit line’s configuration, while the change of the optimal depot location takes place with 10% of the travel demand change. The results have implied a conclusion that to make strategic decisions on transport systems and solving mixed decision problems, forecasting travel demand changes (its volume and structure) over the long-term horizon has to be performed.

An analysis of the influence of selected factors on the accident rate in the construction industry

Hoła, Bożena, Nowobilski, Tomasz, Rudy, Jarosław, Czarnocki, Krzysztof
Article
2018
This paper presents the results of research aimed at constructing a linear mathematical model that determines the influence of selected factors characterising construction production on the accident rate in the construction industry. A number of linear multi-factor mathematical models were developed, which were then compared with each other, and those that best described the analysed phenomena were selected.

A multi-criteria appraisal of the selection of means of urban passenger transport using the Electre and AHP methods

Dudek, Mariusz, Solecka, Katarzyna, Richter, Matthias
Article
2018
This article presents the main components of the multi-criteria decision making (MCDM) methodology and their application in the assessment of several public transportation solutions in a specific traffic corridor. The corridor in question is 15 km long and runs through the centre of Wrocław, Poland. The analysis focused on six alternative scenarios. The following elements were taken into consideration in their design: alternative means of land transport; different types of vehicles and priorities for public transportation; location of bus and tram stops. The individual solutions were assessed based on six criteria designed to measure different aspects of the problem with the use of two alternative MCDM methods: Electre III/IV and AHP. Computational experiments established the final ranking of transport solutions in the corridor from best to worst in terms of the analysed criteria.

Mode choice modelling for urban areas

Birr, Krystian
Article
2018
This article addresses the issue of mode choice modelling using a four-stage travel modelling process. The article indicates limitations of the currently used simplified methods of mode choice modelling and proposes the use of a more detailed approach that accounts for additional, statistically significant factors with the use of advanced mathematical tools and discrete choice models. A need has also been identified to include qualitative factors in forecasting the modal split and in the scenario analyses.