CEEOL - Browse Subjects Result

We kindly inform you that, as long as the subject affiliation of our 300.000+ articles is in progress, you might get unsufficient or no results on your third level or second level search. In this case, please broaden your search criteria.

Study on a Brain-Controlled Pneumatic Actuator to Assist Emergency Braking of a Vehicle

Author(s): Ryszard Dindorf,Jakub Takosoglu,Piotr Wos / Language(s): English Issue: 3/2021

This article deals with the issue of safety within the road freight transport sector with regards to the securing of cargo on a vehicle. The first part of the article focuses on the legal framework that regulates this issue in the Czech Republic. The second part is based on a case study and survey conducted among drivers of the road freight transport vehicles into their awareness of what they understand is meant by securing and secure cargo. The case study was carried out in a specific transport company and includes an analysis of the current situation and concrete measures for improving safety while securing timber for transport.

More...

Assessment of Static Resilience of Objects in the Rail Transport

Author(s): Zdeněk Dvořák,Nikola Chovančíková,Katarína Hoterová,Michal Szatmári / Language(s): English Issue: 3/2021

Resilience is the ability of an object to retain its basic functions in the case of adverse events from an external or internal environment. Adverse events can jeopardize the operation of an object or cause it to become completely inoperable. The assessment of static resilience should be dealt with mainly by objects that are included in local, regional, national, and international critical infrastructure. Critical infrastructure is the basis of today's modern functioning society. The paper is focused on design of the static resilience evaluation of objects in the rail transport. The proposed method of static resilience assessment is based on safety pillars and is applied in a case study to a specific object of the rail transport. This approach is original in the conditions of the Slovak Republic.

More...

Passsenger Ride Comfort and International Roughness Index Specifications in the Slovak Republic

Author(s): Peter Mucka,George Juraj Stein,Peter Tobolka / Language(s): English Issue: 1/2019

New original results are presented on relation between passenger’s whole-body vibration (WBV) and longitudinal road unevenness characterised by the International Roughness Index (IRI) in 100-m segments. Measurements were provided in nine different cars of six vehicle categories operated on about 1860 km of road network. Vibration total value based on the root mean square (RMS) of the frequency-weighted acceleration was used to quantify the ride comfort at seat surface and seat base (i.e. vehicle floor) in three orthogonal axes. The relations between passenger’s acceleration response, comfort reaction levels according to the ISO 2631-1: 1997 and the IRI road unevenness classes, used by the Slovak Road Administration, were estimated. Results indicated higher WBV by ~ 20 % on the motorways than on the 1st and 2nd class roads in the same IRI road class. Using the same IRI road classes for motorways and the 1st and 2nd class roads seems not to be appropriate from the point of view of the whole-body vibrations

More...

Turnout Monitoring with Vehicle Based Inertial Measurements of Operational Trains: A Machine Learning Approach

Author(s): Mykola Sysyn,Dimitri Gruen,Ulf Gerber,Olga Nabochenko,Vitalii Kovalchuk / Language(s): English Issue: 1/2019

A machine learning approach for the recent detection of crossing faults is presented in the paper. The basis for the research are the data of the axle box inertial measurements on operational trains with the system ESAH-F. Within the machine learning approach the signal processing methods, as well as data reduction classification methods, are used. The wavelet analysis is applied to detect the spectral features at measured signals. The simple filter approach and sequential feature selection is used to find the most significant features and train the classification model. The validation and error estimates are presented and its relation to the number of selected features is analysed, as well.

More...

Determination of Parameters of Asynchronous Electric Machines with Asymmetrical Windings of Electric Locomotives

Author(s): Sergey Goolak,Juraj Gerlici,Viktor Tkachenko,Svitlana Sapronova,Tomáš Lack,Kateryna Kravchenko / Language(s): English Issue: 2/2019

This article is devoted to development of a method for calculating the parameters of an asynchronous motor of an electric locomotive with asymmetrical windings of stator and rotor. A method for determining self and mutual inductances of the stator and rotor phases of an asynchronous motor with asymmetric windings and their relations to mechanical variables is proposed. It is based on comparing two equations of stored magnetic energy, one equation calculated through induction, magnetic field strength and geometrical dimensions and another equation calculated through the parameters of the motor circuits. It is shown that the obtained solutions correspond to the previously existing methods, but they give the additional possibilities in mathematical modeling. The proposed technical solution allows higher accuracy developing of a mathematical model of a drive with an asynchronous motor having asymmetrical stator and rotor windings for studying dynamic processes during the operation of the specified drive, in particular, the drive of auxiliary machines for electric locomotive, where an asynchronous motor with asymmetrical stator windings is used as a phase release.

More...

Critical Gaps at Unsignalized Intersections with Bending Right-of-Way

Author(s): Andrea Kocianova,Eva Pitlova / Language(s): English Issue: 4/2018

The capacity calculation procedure for unsignalized intersections is based on the gap-acceptance theory in most of existing capacity regulations and it relies on one of the important parameters - critical gap. However, the capacity calculation procedure and values of critical gaps according to these regulations are valid only for intersections with standard right-of-way (major street leading straight). Nevertheless, in Slovakia, intersections with bending right-of-way (major street not leading straight, but bending) can be encountered. The specific mode of right-of-way results in different priority ranks of traffic movements (set by traffic rules of driving), more complicated traffic situation and therefore, different driver behaviour characteristics. To examine the gap acceptance behaviour of drivers under these specific conditions, an unsignalized four-leg intersection with bending right-of-way located in an urban area of Zilina, Slovakia, was selected. Three different methods (Raff, Wu, and MLM Troutbeck) were used for critical gap estimation from the field data. In the article, results of critical gaps for three through movements of different priority rank (major-street through movement of Rank 2 and minor-street through movements of Rank 3 and 4) are presented. The results show, that the values of critical gaps differ depending on the method by about 3-5 % only, which is not significant. Troutbeck ´s MLM method gives the highest values. The priority rank of movement has the greatest impact on the result. The values of critical gap for major-street through movement of Rank 2 are the smallest; they are approximately 1.3-2.1 s smaller than the values for minor-street through movements of Rank 3 or 4. The highest values of critical gap have been estimated for minor-street through movement of Rank 4 and they are higher compared to the current Slovak regulations TP 102 values for the same priority rank.

More...

Determination of the Appropriate Vehicle Operating in Particular Urban Traffic Conditions

Author(s): Ondrej Stopka,Branislav Šarkan,Maria Chovancova,Larisa Mikhailovna Kapustina / Language(s): English Issue: 2/2017

This paper presents selection of the most appropriate vehicle intended to operate on a particular urban territory, using the specific methods of multi-criteria analysis. For selecting the suitable vehicle, it is necessary to determine a number of specific criteria. In the paper, the desired vehicle is selected from five vehicles, while, each of them has a different product brand. To determine the weights of criteria, the Saaty pairwise comparison method is applied, and subsequently, the multi-criteria evaluation of alternatives is utilized for a research problem.

More...

Concepts of Load Handling Devices, Adjusted to Light Goods Vehicles of The Weight up to 3.5t

Author(s): Paweł Droździel,Kamil Wawer,Radovan Madleňák,Murat Omarbekovich Mussabekov / Language(s): English Issue: 2/2017

The main aim of the article is to present three concepts of load handling devices, adjusted to light goods vehicles of the weight up to 3.5 t. The design issue commissioned by Poczta Polska - the Polish Post was analysed. On the basis of the analysis the design assumptions were taken to design a device. The construction and the method of operation of the design structures suggested by the author were discussed. All the concepts were compared with one another with the use of a SWOT analysis.

More...

Comparison of Operational and Economic Aspects of Direct Road Transport and Continental Combined Transport

Author(s): Jaromir Siroky,Stephan Schroder,Jozef Gasparik / Language(s): English Issue: 2/2017

The aim of this paper is to compare economic and operational aspects in the transition from direct road transport to unaccompanied CT using intermodal road semitrailers. A comparison of specifications of transport units was carried out as well as the risk assessment, considering the probability of a critical situation occurrence. Both of these factors are key for the final decision making. As a main part of this research paper, a comparative case study was conducted. For the purposes of this comparison, data from actual transport orders were used on a route starting in the Czech Republic, going through the industrial Northwest of Germany and then to Belgium and the Netherlands. As a result of this research, the direct cost of road transport and CT were compared considering the lifespan of the used equipment. Besides that, the investment cost for a road carrier to enter the CT system was quantified, which is essential for the CT system development.

More...

Monitoring of Surface Damage in Rails After Long Term Cyclic Loading

Author(s): Katarina Zgutova,Miroslav Neslusan,Juraj Sramek,Peter Danisovic,Jiri Capek / Language(s): English Issue: 2/2017

This paper reports about possible concept in which surface damage of the rail after long tem cyclic loading can be executed. This study employs non destructive magnetic Barkhausen noise as a promising technique which exhibits very good sensitivity against extent of surface damage. Magnetic Barkhausen noise is correlated with the conventional parameters of surface integrity expressed in term of the thickness of damaged layer, its micro hardness as well as stress state. Furthermore, phase analysis of the real surface indicates that extensive phase transformations are produced by the repeated severe plastic deformation. Phase composition of the damaged layer indicates that structure transformation in the rail surface is thermally induced rather than deformation induced process.

More...

Analysis of Out-Of-Plane Stability of Bow-String Arches

Author(s): Jozef Vican,Jaroslav Odrobinak,Jozef Gocal / Language(s): English Issue: 4/2016

Several arch bridge superstructures, designed by the authors of the paper, are presented and analysed. Spatial FEM models were utilised to analyse behaviour of each bridge. Verification of out-of-plane buckling of the arches is discussed in more detail. Comparison of using beam and shell finite elements for the mesh of main beam-arch load-carrying system is given. The variation of top bracing system and its influence on the stability of the arches is presented, as well. A minimum load amplifier to reach the elastic instability of arches is used to estimate the suitability of the bracings. Comparisons of the assessment using results produced by first and second order global analyses are presented. Application of a unique global and local imperfection as the initial geometric imperfection is proposed.

More...

Life Cycle Extension of a Pavement Structure

Author(s): Jan Mikolaj,Lubos Remek,Matus Kozel / Language(s): English Issue: 4/2016

The pavement structure, namely pavement surfacing must meet the criteria required to provide operational service during the whole life cycle of the pavement. Surfacing design composed of layer strengths and proposed materials is defined by design method which calculates the stress state during long-term transport and environmental conditions. The designed surfacing life cycle is defined in respect to traffic load acting on the pavement and road class for a period of about 20 years. Given the practical aspects of road administration, pavement reconstruction is usually due only at the end of the life cycle, when the original materials are replaced by new materials and the layer strength is re-evaluated. Since the overall life cycle of the whole pavement is significantly longer than that of the surfacing, it is necessary to consider possibilities to extend the life cycle of the surfacing either through various technologies, i.e. reinforcement, overlays or recycling. Timing of execution of such action plays a paramount role, and it has impacts on future financial flows of road administrator as well as economic aspects of transportation for the whole society. This paper describes analytical calculations and experimental measurements of surfacing materials, as well as accelerated pavement testing process needed for ascertainment of operational performance of a pavement construction during its life cycle. Finally, a case study encompassing the whole method is presented.

More...

Capacity Limits of Basic Turbo-Roundabouts

Author(s): Andrea Kocianova / Language(s): English Issue: 4/2016

Turbo-roundabouts with their specific design characteristics have become a suitable solution of a single-lane roundabouts capacity problem and a standard two-lane roundabouts safety problem. There is no doubt that turbo-roundabouts ensure a higher level of traffic safety in comparison to standard two-lane roundabouts due to a reduction of both conflict points and driving speed through the turbo-roundabouts. The question is if turbo-roundabouts can provide the same or a higher capacity than standard two-lane roundabouts. The answer, in the form of some important results of the basic turbo-roundabout total capacity at various traffic conditions and also in comparison with standard two-lane roundabouts, is presented in the paper. The capacity model is based on the gap-acceptance theory. Driver behaviour characteristics have been respected according to the Slovak technical guidelines. Redistribution of traffic flows into two lanes at entries and circulatory carriageway of roundabouts has been considered in the capacity calculations. An effective use of both lanes (left and right) has been assumed only at basic turbo-roundabout major entries. By contrast, low use of inner (left) lanes by drivers at entry and circulatory carriageway corresponding with real conditions in some countries has been assumed in the standard two-lane roundabout capacity calculations.

More...

Location Problems in Transportation Networks

Author(s): Peter Czimmermann / Language(s): English Issue: 3/2016

It is known that many optimisation problems on networks are NP-hard. However, it seems that the real transport networks have some interesting properties which allow us to find a "good" solution in reasonable time. In this paper, we suggest and study some new parameters of the transportation networks which could be useful in optimisation problems. We define the evenness and the robustness of the solution. We also concern ourselves with the statistical distribution of distances and edge values in transportation networks.

More...

Driveability Simulation of Vehicle with Variant Tire Properties

Author(s): Michal Lukac,František Brumerčík,Leszek Krzywonos / Language(s): English Issue: 2/2016

The aim of the presented article is to show the possibilities of vehicle tire mathematical model creation and present simulations of a typical driving manoeuvre of a vehicle model equipped with variant tire models.

More...

Comparison of Acceleration Acting on Cargo in Front and in Rear Part of Semi-Trailer during Braking with and without Using the Systems ABS/EBS

Author(s): Jan Zámečník,Juraj Jagelcak,Sven Sokjer-Peterssen / Language(s): English Issue: 2/2016

This article deals with braking tests of semi-trailer truck in forward and rear driving direction. It compares the accelerations and angular velocities in the front and rear part of the semi-trailer and their influence on forces in lashing points when using front lashing. The paper also contains a comparison between forces reached in the lashing points at the rate of cargo weight between the braking tests of semi-trailer and similar braking tests of a van. The first part of the paper contains also possibilities of using tracking devices for detecting accelerations acting on cargo in semi-trailer during transport.

More...

The Possibilities of Dynamic Shipment Weighing in Rail Freight Transport

Author(s): Ján Ližbetin,Petr Vejs,Zdeněk Caha,Lenka Ližbetinová,Philip Michalk / Language(s): English Issue: 2/2016

This article deals with an analysis of the methods of the dynamic weighing of rail vehicles. The measurement of axle load (both static and dynamic) is one of the current standard processes within the technical specifications for interoperability (TSI).

More...

Usage of Polcam Device for Parameter Monitoring and Traffic Flow Modelling

Author(s): Ján Ondruš,Ľubomír Černický / Language(s): English Issue: 2/2016

This article deals with a proposal of using the Polcam PC2006 device for obtaining the traffic flow characteristics. This device is a first of a kind at the University of Zilina. The aim was to perform a practical measurement with a floating vehicle on a selected road section I/18 Zilina - Strecno - Vrutky, evaluate basic characteristics of a traffic flow with consequent modelling and use of software tools. Three measurements were performed in road traffic under different conditions. Individual calculations based on data obtained from practical measurements are processed at the end of the article. The results obtained from the measurement are used for traffic flow modelling in the programme Aimsun.

More...

Different Exegesis of the Concepts Related to Mixed Transport

Author(s): Petr V. Kurenkov,Alexey Astafiev,Olga Kaplina / Language(s): English Issue: 2/2016

This article contains a short history of existing types of mixed transport in Russia and abroad. The system of export freight delivery is analyzed in association with all forms of interaction between various modes of transportation and the subjects of the transport service market (TSM). There is focus not only on the transport complex organization departments and management levels of various modes of transportation, but also on other TSM subjects (carriers, cargo owners, forwarders, stevedores, marine agents, banks, organizations responsible for expertise, customs control and document completion, etc.)

More...

Sensitivity of International Roughness Index to Distresses of Cement Concrete Road Surfaces

Author(s): Peter Mucka / Language(s): English Issue: 1/2016

The paper examined the sensitivity of International Roughness Index (IRI) to the local discontinuities (various distresses, joints, joint and surface defects, other road features, etc.) of the cement concrete (CC) pavements. About 5 300 road records of total length 470 km from Long Term Pavement Performance (LTPP) program were processed. The raw profiles were separated into a random part and a distress part using the median filtering method. The median filter order was set to identify distresses of variable maximum width from 20 to 40 cm, and minimal height, 3 mm. About 26 000 distresses were separated and their dimensions were identified. The raw longitudinal road profiles were compared with the separated pure random parts. The mean relative increase in IRI caused by distresses was 3.3 % for maximum distress width 20 cm, 6.6 % (30 cm), and 10.7 % (40 cm).

More...