Lidé na fakultě
Ing. František Kekula

2024, Infrastructures - Open Access Journal, 9 (1), ISSN 2412-3811

We present a comprehensive methodology for a two-step approach to address the task at hand. The first step involves the optimal placement of charging stations, while the second step focuses on determining the necessary capacity of the charging stations based on traffic factors. This methodology is applicable to countries, states, or specific areas where the placement and optimization of charging stations for truck road transport are being considered. We identify the key inputs required for solving such a task. In the results section, we demonstrate the outcomes using a model example for the Czech Republic.

Článek v periodiku excerpovaném databází Scopus

2024, PROMET - Traffic&Transportation, 36 (6), p. 988-1005), ISSN 1848-4069

This paper attempts to determine the role of street lighting in the spatial clustering of night-time crashes involving pedestrians in the Republic of Croatia. Five-year (2018–2022) night-time pedestrian crash data were used in conditions with and without street lighting. First, distance-based statistical methods were used to assess the spatial clustering and deviations from complete spatial randomness (CRS) of the crash patterns. Second, the global Moran’s I analysis was conducted to investigate a degree of spatial autocorrelation of the annual crash counts aggregated in 21 counties of Croatia. Finally, the local indicators of spatial association (LISA) were used to identify the locations of the crash count hotspots. The results of the ANND analysis confirm a significant clustering of crashes for both street lighting conditions. However, different global Moran’s I values for both conditions were obtained with a high and statistically significant positive value for the crash counts without street lighting. Local Moran's I analysis reveals that the High-High (H-H) county clusters are located in coastal regions of Croatia, while the Low-Low (L-L) county clusters appear in the East continental part, next to Slavonia. The results suggest that inadequate lighting conditions have an impact on the clustering of pedestrian crashes at night.

Článek v periodiku excerpovaném SCI Expanded

2024

Zpráva o činnosti ČVUT FD v roce 2023 při řešení projektu Nástroje kvality dat pro zabezpečení systémové spolehlivosti dopravně informačních center.

Výzkumná zpráva v češtině

2023, Neural Network World, 33 (5), p. 375-396), ISSN 1210-0552

Night-time light (NTL) radiance has a great potential in analyses of dynamic changes in patterns of human activities, and socio-economic and demographic factors. However, most of those analyses are focused on factors at global scales such as the population size, gross domestic product, electric power consumption, fossil fuel carbon dioxide emission etc. In this study we investigate the relationships between three urban lighting indicators and monthly averaged NTL radiance obtained from NASA’s Black Marble monthly NTL composites for 4 study areas in the Czech Republic at local scale. The Pearson correlation analysis was used to identify a strength of the correlations between the indicators and radiance at near-nadir for two different snow conditions. The results from the correlation show that radiance has a strong positive correlation with the number of streetlighting points and their total nominal power, while for the average mast height there were observed moderate correlation coefficients. However, the areas with larger scales have higher correlation coefficients. Moreover, we found that the correlation coefficients are higher for snow-covered condition radiances. Generalized linear (GL) regression analysis was used to examine an association between the radiance and selected indicators. Owing to the excess zeros and overdispersion in the data, the zero-inflated regression performs better than the GL regression. Results from the regression analysis evince a statistically significant relationship between the radiance and selected indicators.

Článek v periodiku excerpovaném SCI Expanded

2022, Batteries, 8 (12), ISSN 2313-0105

In this paper, capacity fade of LiFeYPO4/graphite commercial cells during 116 cycles under different temperatures is studied. The cells were discharged in two modes, during Drive Cycle (DrC) discharge cycles the cell was discharged with current waveform calculated for example battery electric vehicle (BEV) under WLTC 3b drive cycle conditions, whereas during Constant Current (CC) discharge cycles the cell was discharged with a constant current of the same root mean square of the current, as the WLTC 3b current waveform and with the same depth of discharge. All the cells were charged in constant current/constant voltage mode. Two fresh cells were used for each discharge mode at 25 °C and as the results were similar, only one cell per discharge mode was used at the other temperatures 5 °C and 45 °C. Furthermore, simulation P2D model of calendar and cycle life was calibrated based on experimental data. SoC floating was observed during cycling for both discharge modes, accompanied with slight increase in end discharge voltage and growth of energy efficiency. Concluding the results for 25 °C, not waveform character, but the amount of electric charge in combination with calendar aging has the most effect on the cycle life, which is also proved by the simulation. For 5 °C, the capacity fade is milder for DrC discharge cycles, but simulation results do not prove that, which would demand further investigation. The results for 45 °C are apparently dependent on a higher amount of discharged and charged electric charge and influenced by calendar life, simulated capacity fade corresponds quite well to the experiment. The best State of Health (SoH) simulation results are for temperature 45 °C, RMSE is 0.10% SoH, for the other temperatures RMSE is 0.20 and 0.93% SoH for 25 and 5 °C, respectively.

Článek v periodiku excerpovaném SCI Expanded

2021, International Scientific Conference "Horizons of Railway Transport 2020", Elsevier B.V. on behalf of Cairo University), p. 289-304), ISSN 2352-1457

The paper deals with electric charging concept for road freight transport and discusses various kinds of charging stations and their categorization with respect to the connection to a vehicle and type of voltage, fundamental aspects of the design of the electric vehicle charging infrastructure and connection options to the distribution system. The issue of noise, landscape fragmentation and the barrier effect of roads and highways, and emphasizes the influence of freight transport on air pollution, in particular its significant contribution to the production of nitrogen oxides, hydrocarbons, sulfur dioxide, dust particles and other pollutants are mentioned in the paper. A special attention is paid to emissions of carbon dioxide, a significant greenhouse gas, again in the context of freight transport. The methodologies of Well to Wheels (WTW) and Life Cycle Assessment (LCA) are also presented in the paper.

Stať ve sborníku z prestižní konf.

2021, Proceedings of the “Transport Means 2021”, Kaunas, Kaunas University of Technology), p. 1047-1053), ISSN 1822-296X

The article presented here discusses the possibility of use of alternative sources of energy in road freight transport. It deals with emissions from road freight transport and their modelling including the description of emission models, it further introduces a simulation model for fuel consumption and emission calculation, the process of design of optimization of a network charging stations and a concept of charging stations and hydrogen power. The aim is to determine a proper way of implementing alternative energy sources (AES) in freight road transport, to create a simulation model for fuel consumption and emission calculation and therefore to compare the impact of different types of alternative fuels on the environment and to assess emissions in a broader cycle. The work further aims at proposing a method of optimization of a network of charging stations and discussing the concept of charging stations and hydrogen power.

Stať ve sborníku z prestižní konf. (Scopus)

2020, 25. mezinárodní konference Městského inženýrství 2020, Praha, ČKAIT - Česká komora autorizovaných inženýrů a techniků), p. 82-89), ISBN 978-80-88265-25-2

Článek zabývající se potenciálem veřejného osvětlení jako důležité součásti pro problematiku městského inženýrství.

Stať ve sborníku z mezinár. konf. česky

2020, 25. mezinárodní konference Městského inženýrství 2020, Praha, ČKAIT - Česká komora autorizovaných inženýrů a techniků), p. 87-96), ISBN 978-80-88265-25-2

Článek zabývající se potenciálem veřejného osvětlení jako důležité součásti pro problematiku městského inženýrství.

Stať ve sborníku z mezinár. konf. cizojazyčně

2019, 2019 Smart City Symposium Prague, New York, IEEE Press), p. 1-5), ISBN 978-1-7281-0497-3

This paper presents a new approach to pavement rehabilitation using a 3D measuring. The proposed methodology of the pavement rehabilitation overcomes the limitation of the traditional methods of the pavement rehabilitation which cannot achieved the required accuracy. The 3D measuring technology eliminates human faults and improves the total quality of the pavement rehabilitation. The pavement rehabilitation is performed in the concept of Industry 4.0 which is part of Smart City owing to the 3D measuring.

Stať ve sborníku z prestižní konf.

2018

Výzkumná zpráva cizojazyčně