Dissertation theses
Agent heterogeneity in multi-agent models of pedestrian dynamics
Supervisor
Level
Topic of dissertation thesis
Topic description
Specialist supervisor: Ing. Hana Najmanová, Ph.D., prof. RNDr. Pavel Surynek, Ph.D.
Multi-agent (MA) models of pedestrian dynamics become a promising tool supporting an evacuation analysis in performance-based fire safety design. A pedestrian or evacuee is represented in such model by an agent, which parameters, dynamical and interaction rules are inspired by the physical, cognitive, and psychical processes of people in crowd. Recent studies show that very important but rarely considered aspect influencing the evacuation process is the heterogeneity of the crowd in various levels. Most challenging, and so far poorly discussed, is a simulation of a crowd composed of evacuees with essentially different roles and competences during the evacuation (following or giving instructions, keeping or controlling the formation, etc.) as e.g. evacuation of school (pupils vs. teachers) or cultural event (visitors vs. staff).
Goal of the thesis is to fill in this research gap in several of the following aspects:
- Thorough investigation of the influence of essential agents’ heterogeneity on important characteristics of pedestrian flow and evacuation process in most common MA models (cellular, social-force, or rule based).
- Development of new or modification of existing MA models enabling the above-mentioned hierarchical heterogeneity, supporting inter-agent bonds and crowd formations.
- Organization and analysis of evacuation experiments addressing the above-mentioned issues. Comparison of experiments and simulations, development of metrics quantifying the correspondence of heterogeneity in models and reality.
- Investigation of possible strategies of leading/controlling pedestrians/agents influencing the evacuation process by means of the multi-agent path finding or planning tools.
The work should be consulted with both, fire engineering expert and expert on multi-agent planning processes.
Application of random processes in pedestrian flow modelling
Supervisor
Level
Topic of dissertation thesis
Topic description
Specialist supervisor: Mgr. Petr Novák, Ph.D.
Models of pedestrian flow are finding application in various fields including emergency management of an evacuation or large social events, optimization of pedestrian traffic within a department, or non-emergent recreational movement. Most of mathematical and simulation agent-based models of pedestrian flow incorporates several sources of randomness that needs to be taken in account, as e.g.:
• inherent randomness representing variability in human behaviour,
• randomness in internal agent parameters representing variability in human properties and abilities,
• external randomness of the scenario as random arrivals, initial positions, uncertainty in various triggers of change in human behaviour.
Goal of the dissertation is to investigate such sources of randomness from various points of view to be able to simulate such randomness sufficiently realistically for given domain. Furthermore, the importance of introducing the randomness on various levels of the simulation should be investigated by means of sensitivity analysis tools.
Special focus will be given to techniques for simulation of non-Poissonian dependent processes involved in pedestrian flow as e.g. processes with attraction or repulsion between random arrivals of pedestrians and/or triggering events.
The work may be focused more on the analysis of applicability in simulation tools or more theoretically developing the methods for identification and calibration of such processes from observed and measured data.
Bachelor theses
Estimation of Fundamental Diagram from Evacuation Experiments
Author
Juraj Kmec
Year
2021
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Daniel Vašata, Ph.D.
Department
Summary
The fundamental diagram is a crucial characteristic of pedestrian flow that enables engineers to judge the maximum capacity of pedestrian facilities. The classical methods of estimating the fundamental diagram use analytical approximations of this relationship. However, they fail to take into consideration the specific properties of each geometry and the composition of the pedestrians. This thesis presents a data-driven approach to estimating the fundamental diagram via artificial neural networks. This includes simulating evacuations in an open-source pedestrian simulator, computing an alternative measurement of density - the mean distance to k-nearest neighbors, and subsequently training a neural network to estimate the fundamental relationship between density and velocity. The trained models show significant ability to extract the macroscopic relationship from the individual measurements. The prediction is then expanded to include more explanatory variables - the relative positions of nearest neighbors and the relative distance to the exit. This further reduces the prediction error, demonstrating the applicability of machine-learning methods in the field of pedestrian dynamics.
Conflict solution in cellular evacuation model
Author
Matej Šutý
Year
2021
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
prof. RNDr. Pavel Surynek, Ph.D.
Department
Summary
Agent-based cellular models can be used to simulate the process of evacuation of people from a room. The actions and interactions of heterogeneous agents create collective motion and capture complex phenomena of pedestrian dynamics. This thesis presents a multi-agent cellular model based on floor-field model and is extended by a new strategy for solving conflicts when two or more agents attempt to enter the same cell. The agents and the model have various parameters that influence the conflict solution. A sensitivity analysis on these parameters is performed that reveals the individual contribution of variance in the results.
Crossing pedestrian flows - analysis of video records from experiments
Author
Anna Sajdoková
Year
2022
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Jakub Novák
Department
Summary
The thesis focuses on processing and analysis of a video record from crossing pedestrian flows experiment conducted at CTU FNSPE in 2014. The result is an algorithm for automatic extraction of trajectories from this video. Pedestrians in the video had special hats for recognition. The tracking of people is based on hats detection from video frames. Track identity association is done using the shortest distance. When tracking, it can happen that part of the trajectory is missing. The missing parts are approximated by a line segment. Next aim is to recognize binary code from hats. With usage of a convolutional neural network 45\% accuracy was achieved on 20 randomly picked hat samples. The outcome of the thesis is a dataset of trajectories and its analysis using pedestrian flow characteristics (average speed, velocity, density, and fundamental diagram).
Analysis of video records from evacuation experiments - bottleneck
Author
Vít Pospíšil
Year
2022
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Jakub Novák
Department
Summary
This bachelor thesis focuses on the processing of data obtained by the experiment of simulated evacuation of people through narrowed section. Multiple video recordings were made of the experiment, frow which is needed to extract the trajectories of individual's movements using neural networks and computer vision, and then compare and analyze them. The result of the thesis is to obtain trajectories of pedestrians, their comparison with the trajectories obtained by organisator of the experiment, Ing. Marek Bukáček, and to perform statistical analysis of trajectories.
Time-headway prediction by means of data from evacuation experiments
Author
Ondřej Hývnar
Year
2023
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Daniel Vašata, Ph.D.
Department
Summary
Time headway in bottlenecks is an important characteristic of pedestrian behaviour. This thesis reproduces the result of previous research in this field, where several statistical models for prediction of time headway distribution in bottleneck based on walker's surroundings were proposed. I estimate parameters of these models on data from evacuation experiments organized by CTU and discuss the differences with results from previous research.
Simulation of recreational pedestrian movement along the trail in the Luzen valley
Author
Tomáš Novotný
Year
2024
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Jana Vacková, Ph.D.
Department
Summary
This bachelor thesis presents a stochastic agent-based model that simulates pedestrian movement in the Luzen Valley, National Park Šumava. The model merges three distinct mathematical models. Random arrivals of agents are modeled by means of a Poisson process. Further, a fundamental diagram-based model is introduced to transport agents to the estimated bottleneck of the trail. The third microscopical model represents a movement of pedestrians on the bottleneck. The transport section introduces the agent mass in the perceived surroundings of the agent as a novel concept to model interaction between agents that represent pedestrians. Furthermore, kernel estimates are implemented as an individual mass generated by each agent. Due to the focus of this thesis on the transport section of the model, the bottleneck section is represented by a very simple cellular automaton, a totally asymmetric simple exclusion process.
Further, this thesis successfully implemented the model in a simulation tool that has been developed to conduct simulation experiments with the model. The model parameters were calibrated using empirical findings from pedestrian movement. Correctness of kernel implementation was confirmed by one of the experiments. Furthermore, the experiments with the arrival intensity revealed that jams occur at the average arrival intensity of 48 pedestrians per minute. This value corroborates the reasonableness of the transport section model, as it aligns with the empirical findings that were not used for calibration. Additionally, the experiment results validated the assumption that heterogeneity in speed of agents and heterogeneity in arrival intensity leads to earlier stoppages.
Simulation of hospital department - random processes
Author
Lukáš Prendký
Year
2025
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Mgr. Petr Novák, Ph.D.
Department
Summary
This thesis serves as a proof of concept to an upcoming project of simulation of a hospital department conducted by FIT and FA. It first surveys
key theoretical concepts, such as random processes, and proposes several
methods for modifying these processes to meet specific criteria.
The thesis includes implementation of the simulation of processes using SimPy
library in Python and evaluation of impacts of the proposed modifications
on the statistical properties of these processes. Finally, it develops a simple
patientnurse model, which is used to evaluate presence of undesirable behaviour in the simulation. The previously proposed modifications are then
applied to minimize these behaviours, improving the simulations realism.
Simulation of hospital department - algorithmization of processes
Author
Julia Anna Grandcourtová
Year
2025
Type
Bachelor thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
prof. Ing. Vanda Benešová, CSc.
Department
Summary
This bachelor thesis is concerned with the design and implementation of a simulator of hospital department processes. Based on the analysis of the most important aspects of department operation, a subset of a nurse's work involving patient care is selected. Subsequently, the design and implementation of an algorithm using discrete event simulation is introduced. The resulting solution allows nurse events and patient requests to be simulated in a department modelled by the user, as well as visualisation of the simulation. Finally, the results of experiments, in which several methods of assigning patients to nurses and dealing with patient requests in a model department were simulated, are presented.
Master theses
Exit definition influencing simulation of evacuation in agent-based models
Author
Mykola Hotlib
Year
2023
Type
Master thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Daniel Vašata, Ph.D.
Department
Summary
The influence of exit definition on the pedestrian behavior during evacuation is studied via a simulation toolkit based on cellular model. This thesis presents modified Floor-Field model that supports different types of exits. Simulation results compare the influence of exits on different agent configurations: homogeneous, when all agents are equivalent, and heterogeneous, when agents are divided into different groups. The comparison shows that the heterogeneity in aggressiveness and sensitivity to occupation can change the properties of the flow, causing it to lose stationarity and turning it into a linearly decreasing flow, and changing the type of exit in this case can enhance this effect.
Sensitivity analysis of models of cramped interior evacuation
Author
Juraj Kmec
Year
2023
Type
Master thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
Ing. Daniel Vašata, Ph.D.
Department
Summary
The thesis' main goal is to identify the most influential variables in determining the total evacuation time of a simulated egress scenario. Two contrasting geometries are investigated - a double-decker train and a lecture hall. For each of these geometries, two distinct scenarios are considered - a low-density setting where the facility is at approximately 50% capacity, and a high-density setting where the facility is at 90% capacity. These scenarios are analyzed by means of sensitivity analysis with a special focus on the individual sources of randomness in the output - the occupant parameters, their initial positions, and the inherent uncertainty of the simulation process. The crowds in the experiments are made up of two groups of occupants - an able-bodied group with no movement limitations, and a movement-impaired group simulated by a slower maximum speed and a higher acceleration time. The results show that at lower densities, the initial positions of the occupants play a crucial role in determining the total evacuation time, but at higher densities, the macroscopic characteristics of the crowd take over as the most important factors.
Evacuation model with leading and following agents focused on evacuation of (pre)schools
Author
Matej Šutý
Year
2023
Type
Master thesis
Supervisor
doc. Ing. Pavel Hrabák, Ph.D.
Reviewers
prof. RNDr. Pavel Surynek, Ph.D.
Department
Summary
Children, who account for a significant part of the population, are among the most vulnerable during evacuation, along with the sick, elderly, and disabled. Recent experimental research conducted in preschools in the Czech Republic has provided a theoretical foundation for developing a simulation model that captures children's specific behavior during evacuation.
The model proposed in this thesis is a hierarchical system of leading and following agents coordinated by a central planning algorithm. It is based on an extended floor field model. The main contribution of this work lies in analyzing novel strategies and rules for the leading agent, such as it's position within the crowd. The crowd structure is modeled by introducing a pair formation of children moving in queues and examining the leader's influence over the following agents. Finally, the thesis discusses limitations and suggests possible areas for future improvement.