Gintautas Bureika | Vilnius Gediminas Technical University (original) (raw)

Papers by Gintautas Bureika

Lecture notes in intelligent transportation and infrastructure, 2024

Transport Problems

The most-used railway track geometry measurement systems are considered in this study. The advant... more The most-used railway track geometry measurement systems are considered in this study. The advantages and disadvantages of considered systems and the necessity and application of these technologies in European railways were examined. The decisive factors of the operation of measurement equipment were considered. Real-time railway track condition monitoring systems were evaluated by 14 experts according to a scale of 13 criteria. Questionnaire data were processed using Kendall’s rank correlation method, and the mean ranks were normalized using the average rank transformation into weight method. The most relevant evaluation criteria describing the principles of operation and quality of the most promising technologies were defined. The most important criteria for assessing the suitability of technologies were determined by applying the technique for order of preference by similarity to ideal solution. Finally, basic conclusions and recommendations were formulated.

Transport Problems

The final model for rail transportation is the introduction of full digitalization to support com... more The final model for rail transportation is the introduction of full digitalization to support communication and transport services, which will be available to the public in the future. The process of digitalization is based on models that reproduce the real physical structures present in the transport network. Due to the high complexity of the structure and its mapping, it is necessary to find methods that automatically verify the proposed created model. This approach supports manual activities that, at this moment, are not sufficient. Automatization’s description requires a formal approach. Such a description has been developed as part of a research project, “The Digital Railway. The digital twin of the ETCS application. Virtual prototyping and simulation of operational scenarios.” In this paper, a formal model of the ETCS application has been proposed, and a formal approach to its verification is described.

Transport, Mar 27, 2015

In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, rel... more In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, reliability and durability performance. The main dynamic indicators include the vertical K vd and horizontal K hd dynamic coefficients as well as the stability coefficient K s , which determines the wheel flange resistance to derailment. The article compares dynamic indications for three different types of bogies. There were no tangible differences observed for all the three different types of bogies running at a speed of 40 to 120 km/h on a direct tangent rail section. Nevertheless, there is a realistic potential to improve the dynamic indicators of a freight wagon by rationalising suspension unit parameters.

Straipsnyje nagrinėjama viena pagrindinių riedmenų dinamikos savybių – vagono judėjimo tolygumas.... more Straipsnyje nagrinėjama viena pagrindinių riedmenų dinamikos savybių – vagono judėjimo tolygumas. Riedmenų judėjimo tolygumas vertinamas jų pakabos svyravimo procesų ir vibracijų parametrais. Judant bėgių kelio nelygumais, sužadinami priverstiniai kėbulo, pakabos ir važiuoklės elementų svyravimai. Programiniu paketu „Universal Mechanism“ modeliuojamas keleivinio vagono judėjimas keliu su duotais vertikaliais ir skersiniais bėgių nelygumais. Isnagrinėta vagono kėbulo svyravimų amplitudžių priklausomybė nuo bėgių kelio nelygumų bei vertikaliųjų ir skersinių pakabos poslinkių. Straipsnyje taip pat isanalizuotas vagono stabilumo nuvažiavimui nuo bėgių Nadalio kriterijus, kintant pakabos parametrų standumui ir judėjimo greiciui.

Mokslas - Lietuvos ateitis, Dec 19, 2013

Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio e... more Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio elemento (platformos tiltelio) stipruminis tyrimas. Nustatoma tiltelį veikianti apkrova bei apkrovos koncentracijos vietos. Straipsnyje trumpai aprašomi tiltelio konstrukciniai elementai ir, naudojant "SolidWorks" programinį paketą, braižomas pats tiltelis. Tiltelio konstrukciją veikiančios apkrovos tiriamos "Ansys" programiniu paketu. Pagal atlikto apkrovų modeliavimo rezultatus patvirtinamos pavojingos konstrukcinės tiltelio zonos. Siekiant išspręsti nustatytą konstrukcinę automobilvežio platformos elemento problemą, pasiūlytas konstrukcijos tobulinimas, atliktas šios konstrukcijos apkrovų ir įtempimų pasiskirstymo modeliavimas. Formuluojamos išvados bei pasiūlymai.

Ecology and the Environment, Apr 11, 2011

Energy recovery is an effective method of energy saving which can be used for traction in freight... more Energy recovery is an effective method of energy saving which can be used for traction in freight transportation by railway. In this area, energy recovery is a process of converting the kinetic energy of a moving train in electricity, which is transferred to another energy consumer (another train using the traction energy) through a catenary. Energy recovery can be effectively used for carrying various raw materials (e.g. timber, oil, etc.) to seaports by railway. The loaded wagons which are much heavier than unloaded wagons carry goods "down" to the seaports, while empty trains return (i.e. go 'upward') to the continent. The seaports are only several meters above the sea level, while the places of freight dispatching can be hundreds of meters, or even kilometres, above the sea level. The asymmetry of freight flows (when the freight flow directed "downwards" is several times heavier than 'upward' freight flow) may be effectively used for energy recovery. The research performed shows that, given an appropriate combination of the asymmetry of the freight flows in opposite directions and particular track gradient, the potential energy of freight trains may be used for freight transportation by applying energy recovery techniques. This allows the authors to make an assumption that this could serve a theoretical basis for making feasible one-way freight transportation by using only the recovered energy of the train. On the other hand, taking into account the rolling resistance of the train, there should be some limiting values of the ratio of the freight flows in the opposite directions, and the track gradient should not have small values (e.g. track gradient or the ratio of freight flows should not be too low). If that is the case, the inertial freight transportation is not possible, and an external energy source sufficient to overcome the rolling resistance of the train is required.

Mokslas - Lietuvos ateitis, Nov 28, 2012

Santrauka. Straipsnyje nagrinėjami šiuo metu AB ,,Lietuvos geležinkeliai" kroviniams vežti naudoj... more Santrauka. Straipsnyje nagrinėjami šiuo metu AB ,,Lietuvos geležinkeliai" kroviniams vežti naudojami traukos riedmenys: analizuojami ir lyginami techniniai duomenys, vertinamos eksploatavimo sąnaudos. Įvertinus krovinių srautų prognozes tiesiamoje ,,Rail Baltica" geležinkelio magistralėje, pasiūlytas traukos riedmenų kroviniams vežti parinkimo algoritmas. Šilumvežių šioje magistralėje naudojimo efektyvumas nustatomas trimis daugiakriterio įvertinimo metodais: vietų sumos metodu, rodiklių įverčio metodu ir geometrinio vidurkio metodu. Šilumvežiai vertinami techniniais, ekonominiais ir ekologiniais aspektais. Keičiant kriterijų svarbos koeficientų reikšmes, nustatyti skirtingi riedmenų panaudojimo efektyvumo rezultatai.

Transport Problems

The European Railway Agency has formulated assumptions for a target model of rail transport. Its ... more The European Railway Agency has formulated assumptions for a target model of rail transport. Its important premise is digitalization to support the communication and transport services that the railways will make available to the public in the future. Part of the digitalization process is the digital description of the railway infrastructure in a formalized form to allow algorithmic processing. The formal description of infrastructure is not a new issue. However, attempts made so far have not resulted in a permanent definition of a generally accessible formalism allowing for a coherent representation of the physical railway infrastructure in a digital form. This paper presents the results of work carried out within the research project Digital Railway-The Digital Twin of the ETCS Application-Virtual Prototyping and Simulation of Operational Scenarios.

Purpose. The most pressing problem facing the rail traffic safety experts is an accident rate at ... more Purpose. The most pressing problem facing the rail traffic safety experts is an accident rate at the railway level crossings. The purpose is to investigate the circumstances, which affect traffic safety at the level crossings, and to offer effective tools for experts to improve the safety the problems of these dangerous spaces of railway infrastructure. Methodology. This paper observes the logistic regression as a method to estimate the accident rate at level crossings in Lithuania. The authors have studied and evaluated the key factors affecting the safety of railway crossings. These factors are the intensity of trains and road transport means through the railway level crossing, the visibility of the approaching train from both sides of the traffic, the maximum permissible speed of the trains, the number of tracks (single track, double track, and multi-track), the level of installed alarm and automatic equipment, a density of population in this area, etc. Finally, only the factors,...

Lecture notes in networks and systems, 2020

The problematics of decarbonisation in road transport sector is considered in this chapter. The i... more The problematics of decarbonisation in road transport sector is considered in this chapter. The impact of growing motor vehicle fleet on pollutant by carbon dioxide (CO2) gases of atmosphere is analysed. The detail analysis of purposeful restriction of permissible level of comparative amount CO2 in car exhaust gases in EU to control the total CO2 emission in road transport sector is presented. The urgent demand to use carbonless fuel additives to stop the growth of total amount of CO2 emission during vehicle traction transient process “from heat power to electric power” is clarified. The introduction of electric cars by itself does not solve the problem of decarbonisation, since it is necessary to assess how electricity is produced, whether from renewable sources or by burning fossil fuel. The objective reasons for the delay in the widespread implementation of electric vehicles are investigated: the distance of one battery charge dissatisfied with drivers, an underdeveloped network of battery recharging stations, problems with the capacity and overloads of state-run electric networks, aspects of determination of time for recharging private cars, and insufficient government support measures. The main characteristics of the integrity of biofuel production and use and the continuous biofuel supply chain are described. Direct and indirect the 4th generation biofuel production processes, photo-fermentation and gaseous reversible reaction for hydrogen production are described. Using of hydrogen as carbonless fuel for internal combustion engines (ICE) slightly improves the burning processes of ICE combustible mixture and this decreases on ICE emission harmfulness. The undisputed advantages of hydrogen as ICE fuel additive encourages the development of hydrogen re-fulling infrastructure. Gained results of performed stand tests to define the efficiency of ICE and exhaust gases toxicity using Brown’s gas (HHO) are described. Finally, basic conclusions are given.

Transport, Jun 30, 2008

The determination problem of adhesion coefficient of locomotives' wheels with rails is described ... more The determination problem of adhesion coefficient of locomotives' wheels with rails is described in this paper. The use of methods of mathematical statistics and theory of probability provides wider possibilities for determining the most acceptable (suitable) value of the adhesion coefficient. The random factors influencing on this value are analysed. The use of the adhesion coefficient values based on reliable research results could help maintain uninterrupted (continuous) traffic of heavy freight trains and increase not only the carrying capacity, but also the volume of the transported goods. The paper considers a mathematical model of steady traffic of heavy freight trains pulled by upgraded locomotives of the series 2M62M on railway line with a gradient. The research results show that the actual values of the adhesion coefficient and the total resistance are distributed according to the normal distribution law. A mode of locomotive motion largely depends on the relationship between the total train's running resistance and locomotive tractive force. Finally, basic conclusions are given.

Vehicle System Dynamics, Feb 29, 2016

ABSTRACT The simplified method to determine a vertical impact force of wheel with flat and rail i... more ABSTRACT The simplified method to determine a vertical impact force of wheel with flat and rail interaction is presented in this article. The presented simplified method can be used to identify maximum contact force and its distribution in the contact length between the damaged wheel and the rail. The vertical impact force depends on geometrical parameters of the rail and wheel with flat, speed of vehicle and the angle of deviation of rail. This article demonstrates the influence of wheel with flat geometrical parameters, speed of vehicle to maximum contact force and its distribution in the contact zone. The obtained values of the simplified method for determination of a vertical contact force are compared with the results obtained from field measurements.

Transport, Apr 12, 2011

The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K,... more The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K, 2M62M and ER20CF, suggesting the ways of their reduction. Given the damages of the old locomotive M62 and the structure of its operating expenses, some methods of Diesel locomotives' upgrading are offered. Service life of new generation Diesel locomotives SIEMENS ER20CF and the locomotives 2M62K, 2M62M after the upgrade are determined. The taxes on air pollution by the exhaust gases of Diesel engines are calculated for the locomotives of each series. The effectiveness of operation of freight Diesel locomotives is calculated by three multicriteria evaluation methods and the most efficient freight Diesel locomotive for Lithuanian Railways is determined based on a set of criteria. Basic conclusions are also given.

Straipsnyje aprašomas Lietuvos geležinkelių pervažų eismo rizikos lygio įvertinimas. Išanalizavus... more Straipsnyje aprašomas Lietuvos geležinkelių pervažų eismo rizikos lygio įvertinimas. Išanalizavus Lietuvos bei užsienio pastarųjų metų geležinkelių eismo įvykių statistinius duomenis, nustatyta, kad pervažose įvyksta apie 30 % visų geležinkelių transportui priskiriamų eismo įvykių. Tiriant šalies pervažų saugumą, vertinami jų techniniai kriterijai. Pritaikius binarinės logistinės regresijos modelį, apskaičiuojamos eismo įvykio tikimybių reikšmės šalies pervažose. Nustatoma pavojingiausių Vilniaus, Kauno, Šiaulių bei Klaipėdos regionų pervažų rizika. Pagal gautus rezultatus, atsižvelgiant į eismo įvykio tikimybę, pervažos sureitinguojamos. Pabaigoje pateikiami tyrimo rezultatai bei išvados.

Lecture notes in intelligent transportation and infrastructure, 2024

Transport Problems

The most-used railway track geometry measurement systems are considered in this study. The advant... more The most-used railway track geometry measurement systems are considered in this study. The advantages and disadvantages of considered systems and the necessity and application of these technologies in European railways were examined. The decisive factors of the operation of measurement equipment were considered. Real-time railway track condition monitoring systems were evaluated by 14 experts according to a scale of 13 criteria. Questionnaire data were processed using Kendall’s rank correlation method, and the mean ranks were normalized using the average rank transformation into weight method. The most relevant evaluation criteria describing the principles of operation and quality of the most promising technologies were defined. The most important criteria for assessing the suitability of technologies were determined by applying the technique for order of preference by similarity to ideal solution. Finally, basic conclusions and recommendations were formulated.

Transport Problems

The final model for rail transportation is the introduction of full digitalization to support com... more The final model for rail transportation is the introduction of full digitalization to support communication and transport services, which will be available to the public in the future. The process of digitalization is based on models that reproduce the real physical structures present in the transport network. Due to the high complexity of the structure and its mapping, it is necessary to find methods that automatically verify the proposed created model. This approach supports manual activities that, at this moment, are not sufficient. Automatization’s description requires a formal approach. Such a description has been developed as part of a research project, “The Digital Railway. The digital twin of the ETCS application. Virtual prototyping and simulation of operational scenarios.” In this paper, a formal model of the ETCS application has been proposed, and a formal approach to its verification is described.

Transport, Mar 27, 2015

In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, rel... more In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, reliability and durability performance. The main dynamic indicators include the vertical K vd and horizontal K hd dynamic coefficients as well as the stability coefficient K s , which determines the wheel flange resistance to derailment. The article compares dynamic indications for three different types of bogies. There were no tangible differences observed for all the three different types of bogies running at a speed of 40 to 120 km/h on a direct tangent rail section. Nevertheless, there is a realistic potential to improve the dynamic indicators of a freight wagon by rationalising suspension unit parameters.

Straipsnyje nagrinėjama viena pagrindinių riedmenų dinamikos savybių – vagono judėjimo tolygumas.... more Straipsnyje nagrinėjama viena pagrindinių riedmenų dinamikos savybių – vagono judėjimo tolygumas. Riedmenų judėjimo tolygumas vertinamas jų pakabos svyravimo procesų ir vibracijų parametrais. Judant bėgių kelio nelygumais, sužadinami priverstiniai kėbulo, pakabos ir važiuoklės elementų svyravimai. Programiniu paketu „Universal Mechanism“ modeliuojamas keleivinio vagono judėjimas keliu su duotais vertikaliais ir skersiniais bėgių nelygumais. Isnagrinėta vagono kėbulo svyravimų amplitudžių priklausomybė nuo bėgių kelio nelygumų bei vertikaliųjų ir skersinių pakabos poslinkių. Straipsnyje taip pat isanalizuotas vagono stabilumo nuvažiavimui nuo bėgių Nadalio kriterijus, kintant pakabos parametrų standumui ir judėjimo greiciui.

Mokslas - Lietuvos ateitis, Dec 19, 2013

Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio e... more Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio elemento (platformos tiltelio) stipruminis tyrimas. Nustatoma tiltelį veikianti apkrova bei apkrovos koncentracijos vietos. Straipsnyje trumpai aprašomi tiltelio konstrukciniai elementai ir, naudojant "SolidWorks" programinį paketą, braižomas pats tiltelis. Tiltelio konstrukciją veikiančios apkrovos tiriamos "Ansys" programiniu paketu. Pagal atlikto apkrovų modeliavimo rezultatus patvirtinamos pavojingos konstrukcinės tiltelio zonos. Siekiant išspręsti nustatytą konstrukcinę automobilvežio platformos elemento problemą, pasiūlytas konstrukcijos tobulinimas, atliktas šios konstrukcijos apkrovų ir įtempimų pasiskirstymo modeliavimas. Formuluojamos išvados bei pasiūlymai.

Ecology and the Environment, Apr 11, 2011

Energy recovery is an effective method of energy saving which can be used for traction in freight... more Energy recovery is an effective method of energy saving which can be used for traction in freight transportation by railway. In this area, energy recovery is a process of converting the kinetic energy of a moving train in electricity, which is transferred to another energy consumer (another train using the traction energy) through a catenary. Energy recovery can be effectively used for carrying various raw materials (e.g. timber, oil, etc.) to seaports by railway. The loaded wagons which are much heavier than unloaded wagons carry goods "down" to the seaports, while empty trains return (i.e. go 'upward') to the continent. The seaports are only several meters above the sea level, while the places of freight dispatching can be hundreds of meters, or even kilometres, above the sea level. The asymmetry of freight flows (when the freight flow directed "downwards" is several times heavier than 'upward' freight flow) may be effectively used for energy recovery. The research performed shows that, given an appropriate combination of the asymmetry of the freight flows in opposite directions and particular track gradient, the potential energy of freight trains may be used for freight transportation by applying energy recovery techniques. This allows the authors to make an assumption that this could serve a theoretical basis for making feasible one-way freight transportation by using only the recovered energy of the train. On the other hand, taking into account the rolling resistance of the train, there should be some limiting values of the ratio of the freight flows in the opposite directions, and the track gradient should not have small values (e.g. track gradient or the ratio of freight flows should not be too low). If that is the case, the inertial freight transportation is not possible, and an external energy source sufficient to overcome the rolling resistance of the train is required.

Mokslas - Lietuvos ateitis, Nov 28, 2012

Santrauka. Straipsnyje nagrinėjami šiuo metu AB ,,Lietuvos geležinkeliai" kroviniams vežti naudoj... more Santrauka. Straipsnyje nagrinėjami šiuo metu AB ,,Lietuvos geležinkeliai" kroviniams vežti naudojami traukos riedmenys: analizuojami ir lyginami techniniai duomenys, vertinamos eksploatavimo sąnaudos. Įvertinus krovinių srautų prognozes tiesiamoje ,,Rail Baltica" geležinkelio magistralėje, pasiūlytas traukos riedmenų kroviniams vežti parinkimo algoritmas. Šilumvežių šioje magistralėje naudojimo efektyvumas nustatomas trimis daugiakriterio įvertinimo metodais: vietų sumos metodu, rodiklių įverčio metodu ir geometrinio vidurkio metodu. Šilumvežiai vertinami techniniais, ekonominiais ir ekologiniais aspektais. Keičiant kriterijų svarbos koeficientų reikšmes, nustatyti skirtingi riedmenų panaudojimo efektyvumo rezultatai.

Transport Problems

The European Railway Agency has formulated assumptions for a target model of rail transport. Its ... more The European Railway Agency has formulated assumptions for a target model of rail transport. Its important premise is digitalization to support the communication and transport services that the railways will make available to the public in the future. Part of the digitalization process is the digital description of the railway infrastructure in a formalized form to allow algorithmic processing. The formal description of infrastructure is not a new issue. However, attempts made so far have not resulted in a permanent definition of a generally accessible formalism allowing for a coherent representation of the physical railway infrastructure in a digital form. This paper presents the results of work carried out within the research project Digital Railway-The Digital Twin of the ETCS Application-Virtual Prototyping and Simulation of Operational Scenarios.

Purpose. The most pressing problem facing the rail traffic safety experts is an accident rate at ... more Purpose. The most pressing problem facing the rail traffic safety experts is an accident rate at the railway level crossings. The purpose is to investigate the circumstances, which affect traffic safety at the level crossings, and to offer effective tools for experts to improve the safety the problems of these dangerous spaces of railway infrastructure. Methodology. This paper observes the logistic regression as a method to estimate the accident rate at level crossings in Lithuania. The authors have studied and evaluated the key factors affecting the safety of railway crossings. These factors are the intensity of trains and road transport means through the railway level crossing, the visibility of the approaching train from both sides of the traffic, the maximum permissible speed of the trains, the number of tracks (single track, double track, and multi-track), the level of installed alarm and automatic equipment, a density of population in this area, etc. Finally, only the factors,...

Lecture notes in networks and systems, 2020

The problematics of decarbonisation in road transport sector is considered in this chapter. The i... more The problematics of decarbonisation in road transport sector is considered in this chapter. The impact of growing motor vehicle fleet on pollutant by carbon dioxide (CO2) gases of atmosphere is analysed. The detail analysis of purposeful restriction of permissible level of comparative amount CO2 in car exhaust gases in EU to control the total CO2 emission in road transport sector is presented. The urgent demand to use carbonless fuel additives to stop the growth of total amount of CO2 emission during vehicle traction transient process “from heat power to electric power” is clarified. The introduction of electric cars by itself does not solve the problem of decarbonisation, since it is necessary to assess how electricity is produced, whether from renewable sources or by burning fossil fuel. The objective reasons for the delay in the widespread implementation of electric vehicles are investigated: the distance of one battery charge dissatisfied with drivers, an underdeveloped network of battery recharging stations, problems with the capacity and overloads of state-run electric networks, aspects of determination of time for recharging private cars, and insufficient government support measures. The main characteristics of the integrity of biofuel production and use and the continuous biofuel supply chain are described. Direct and indirect the 4th generation biofuel production processes, photo-fermentation and gaseous reversible reaction for hydrogen production are described. Using of hydrogen as carbonless fuel for internal combustion engines (ICE) slightly improves the burning processes of ICE combustible mixture and this decreases on ICE emission harmfulness. The undisputed advantages of hydrogen as ICE fuel additive encourages the development of hydrogen re-fulling infrastructure. Gained results of performed stand tests to define the efficiency of ICE and exhaust gases toxicity using Brown’s gas (HHO) are described. Finally, basic conclusions are given.

Transport, Jun 30, 2008

The determination problem of adhesion coefficient of locomotives' wheels with rails is described ... more The determination problem of adhesion coefficient of locomotives' wheels with rails is described in this paper. The use of methods of mathematical statistics and theory of probability provides wider possibilities for determining the most acceptable (suitable) value of the adhesion coefficient. The random factors influencing on this value are analysed. The use of the adhesion coefficient values based on reliable research results could help maintain uninterrupted (continuous) traffic of heavy freight trains and increase not only the carrying capacity, but also the volume of the transported goods. The paper considers a mathematical model of steady traffic of heavy freight trains pulled by upgraded locomotives of the series 2M62M on railway line with a gradient. The research results show that the actual values of the adhesion coefficient and the total resistance are distributed according to the normal distribution law. A mode of locomotive motion largely depends on the relationship between the total train's running resistance and locomotive tractive force. Finally, basic conclusions are given.

Vehicle System Dynamics, Feb 29, 2016

ABSTRACT The simplified method to determine a vertical impact force of wheel with flat and rail i... more ABSTRACT The simplified method to determine a vertical impact force of wheel with flat and rail interaction is presented in this article. The presented simplified method can be used to identify maximum contact force and its distribution in the contact length between the damaged wheel and the rail. The vertical impact force depends on geometrical parameters of the rail and wheel with flat, speed of vehicle and the angle of deviation of rail. This article demonstrates the influence of wheel with flat geometrical parameters, speed of vehicle to maximum contact force and its distribution in the contact zone. The obtained values of the simplified method for determination of a vertical contact force are compared with the results obtained from field measurements.

Transport, Apr 12, 2011

The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K,... more The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K, 2M62M and ER20CF, suggesting the ways of their reduction. Given the damages of the old locomotive M62 and the structure of its operating expenses, some methods of Diesel locomotives' upgrading are offered. Service life of new generation Diesel locomotives SIEMENS ER20CF and the locomotives 2M62K, 2M62M after the upgrade are determined. The taxes on air pollution by the exhaust gases of Diesel engines are calculated for the locomotives of each series. The effectiveness of operation of freight Diesel locomotives is calculated by three multicriteria evaluation methods and the most efficient freight Diesel locomotive for Lithuanian Railways is determined based on a set of criteria. Basic conclusions are also given.

Straipsnyje aprašomas Lietuvos geležinkelių pervažų eismo rizikos lygio įvertinimas. Išanalizavus... more Straipsnyje aprašomas Lietuvos geležinkelių pervažų eismo rizikos lygio įvertinimas. Išanalizavus Lietuvos bei užsienio pastarųjų metų geležinkelių eismo įvykių statistinius duomenis, nustatyta, kad pervažose įvyksta apie 30 % visų geležinkelių transportui priskiriamų eismo įvykių. Tiriant šalies pervažų saugumą, vertinami jų techniniai kriterijai. Pritaikius binarinės logistinės regresijos modelį, apskaičiuojamos eismo įvykio tikimybių reikšmės šalies pervažose. Nustatoma pavojingiausių Vilniaus, Kauno, Šiaulių bei Klaipėdos regionų pervažų rizika. Pagal gautus rezultatus, atsižvelgiant į eismo įvykio tikimybę, pervažos sureitinguojamos. Pabaigoje pateikiami tyrimo rezultatai bei išvados.