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Abstract

This paper focus on description of railway safety system radioblock and its application. Content of the paper describes usefulness of this system on those railway lines, which have been operated according to norm about simplified supervision of railway operation. Theoretical basis of the research is proved by case study on the railway line Číčenice – Volary (Czechia). This railway line is the only railway line with this safety system nowadays. Application of these issues is evaluated from safety and technology point of view. There are some suggestions for other railway lines, which are suitable for radioblock railway safety system.

Abstract

The paper deals with the analysis of the development of mobile devices and current trends in their use and development. The relevance of the article is in its linking history and present. The article points to milestones in historical development and future trends and development of mobile devices. Today, mobile devices affect all areas of human life, whether private or business. Mobile devices are now able to replace computers and laptops, so the user has the information they always have with them. The development of mobile devices inherently includes systems supporting their functioning, which the article also discusses.

Abstract

The effectiveness of regional railway lines has been a much discussed theme recently mainly in case of lines which are not sufficient per the capacity requirements of carriers, or vice-versa, which are utilised only to a minimum extent. The article deals with the assessment of options how to utilise the railway line Hodonín - Holíč nad Moravou with respect to its inclusion into Revision of Transport Expenses document. Based on the analysis of present operation situation in that border crossing as well as on the analysis of passenger and freight railway transport operation various options of utilising the line have been investigated with respect to operation and economic options of individual alternatives.

Abstract

Transport and its major part of transport means is currently based on the internal combustion engine principle. For these engines, the primary energy source is oil, natural gas, coal, biomass and others. These primary energy sources and their processing in refineries and factories are used to produce products that are used to drive engines - fuels. From what energy sources these fuels will be produced and what technology will be used to process and produce them is also an important. This whole process must take the reduction of total emissions into account. Future fuels can be considered synthetically produced diesel or hydrogen, which can later significantly affect the decrease in emissions from their processing, production and subsequent combustion of these more environmentally friendly types of fuels. This article processes analyses and development of basic pollutants, total emissions and energy consumption in the Slovak Republic and the EU. In the second part there is an evaluation of the emissions trend development in transport in the EU and Slovakia.

Abstract

Predictive modeling is the key fundamental method to study passengers’ behavior in transportation research. One of the limited studied topic is modeling of public transport usage frequency, which can be used to estimate present and future demand and users’ trend toward public transport services. The artificial intelligence and machine learning methods are promising to be better substitute to statistical techniques. No doubt, traditionally been used econometrics models are better for causal relationship studies among variables, but they made rigid assumptions and unable to recognize the pattern in data. This paper aims to build a predictive model to solve passengers’ classification, and public transport usage frequency using socio-demographic survey data. The supervised machine learning algorithm, K-Nearest Neighbor (KNN) applied to build a predictive model, which is the better machine learning method for dealing with small datasets, because of its ability of having less parameter tuning. Survey data has been used to train and validate the model performance, which is able to predict public transport usage frequency of future users of public transport. This model can practically be used by public transport agencies and relevant government organizations to predict the public transport demand for new commuters before introducing any new transportation projects.

Abstract

In this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

Abstract

The purpose of this paper is to establish the intersection curves between cylinders, using Mathematica program. The equations curves which are inferred by mathematical methods are introduced in this program. This paper takes into discussion the case of four cylinders.

Abstract

The paper presents a numerical method of kinematical analysis of the articulated quadrilateral mechanism. Starting from Euler’s relation concerning the distribution of speeds written in projections on the fixed reference system axes, a system of differential equations describing the movement of the mechanism was obtained. This system of differential equations was then solved using numerical integration methods and the variation with respect to time of the position kinematical parameters, of the velocities (the first order kinematical parameters), and of the accelerations (the second order kinematical parameters), was obtained. Matrix writing of the differential equations was used in order to make the differential equations set out in the paper easier to solve using the electronic computer.

Abstract

The paper deals with the complete kinematical analysis of the mechanism that enters the machine tool structure designed to generate, in particular, plane surfaces. A machine tool of this kind is called shaping machine. For this purpose, Euler’s relations concerning the velocities distribution, written in projections on the fix reference system axes will be used. Starting from these relations we will get to a system of the first order linear differential equations whose unknowns are the kinematical parameters of the mechanism elements. The variation in time of these parameters will be obtained by solving the differential equations system the differential equations system using numerical integration methods.

Abstract

Refractory concretes with the usual cement content (about 20%) present, besides their well-known advantages, several important disadvantages which make such concretes unfit for certain applications. The relatively high CaO content in concretes, the presence of even small amounts of SiO2 and Fe2O3 in cement reduce in the first place the concretes refractoriness; if their relatively high porosity is also taken into account, the concretes behavior is further damaged in regard to the structural and thermal-chemical stability. especially at their high operating temperatures. This work is an attempt to correct the shortcomings shown by reducing the cement dosage and using appropriate admixtures in the technological process of concrete making.