Katarzyna Harezlak

Silesian University of Technology · Institute of Computer Science

The ability to uncover characteristics based on empirical measurement is an important step in understanding the underlying system that gives rise to an observed time series. This is especially important for biological signals whose characteristic contributes to the underlying dynamics of the physiological processes. Therefore, by studying such sign...

A novel approach for eye-typing using an on-screen keyboard was proposed in the paper. It was compared with the two applied in the previous studies. All utilized the dwell-time selection for writing letters, set to 1000 ms. This value was chosen due to the planned group of participants. Among 14 engaged people, there were four over the age of 50 an...

Photoplethysmography (PPG) is a non-invasive optical technique, applied in clinical settings to measure arterial oxygen saturation. Using modern technology, PPG signals can be measured by wearable devices. This paper presents a novel procedure to study the dynamics of biomedical signals. The procedure uses features of a wavelet scattering transform...

The purpose of the paper is to study how changes in neural network architecture and its hyperparameters affect the results of biometric identification based on keystroke dynamics. The publicly available dataset of keystrokes was used, and the models with different parameters were trained using this data. Various neural network layers—convolutional,...

During eye-tracking experiments, a large amount of data is collected. Usually, it is stored in text files, or file formats meant for scientific data. Because these formats provide limited sets of mechanisms for more comprehensive data analysis, various database models were considered as an alternative for them in this study. They included a relatio...

The paper focuses on utilizing eye movements for controlling computer programs. Four different approaches were considered, including gazing at an element, blinking, and two solutions for eye gestures. The methods were implemented in a simple photo viewer. However, the developed functionalities can be utilized in other applications (switching e-book...

The paper presents studies on biometric identification methods based on the eye movement signal. New signal features were investigated for this purpose. They included its representation in the frequency domain and the largest Lyapunov exponent, which characterizes the dynamics of the eye movement signal seen as a nonlinear time series. These featur...

The research aimed to compare eye movement patterns of people looking at faces with different but subtle teeth imperfections. Both non-specialists and dental experts took part in the experiment. The research outcome includes the analysis of eye movement patterns depending on the specialization, gender, age, face gender, and level of teeth deformati...

Eye movement-based biometric has been developed for over 15 years, but for now - to the authors' knowledge - no commercial applications utilize this modality. There are many reasons for this, starting from still low accuracy and ending with the problematic setup. One of the essential elements of this setup is the calibration , as nearly every eye t...

It seems that controlling games with the eyes should be very intuitive and obvious. However, eye-controlled games have not become very popular yet. One of the reasons is - in our opinion - the necessity of eye tracker calibration before its every usage. This process is not very long, but it is inconvenient and requires focusing on the particular ta...

The methods for nonlinear time series analysis were used in the presented research to reveal eye movement signal characteristics. Three measures were used: approximate entropy, fuzzy entropy, and the Largest Lyapunov Exponent, for which the multilevel maps (MMs), being their time-scale decomposition, were defined. To check whether the estimated cha...

This book includes a selection papers describing the latest advances and discoveries in the field of human-computer interactions, which were presented at the 6th International Conference on Man-Machine Interactions, ICMMI 2019, held in Cracow, Poland, in October 2019. Human-computer interaction is a multidisciplinary field concerned with the desig...

The aim of the research is the introduction of new techniques that enable a visual comparison of scan-paths. Every eye tracking experiment produces many scan-paths, and one of the main challenges of eye tracking analysis is how two compare these scan-paths. A classic solution is to extract easily measurable features such as fixation durations or sa...

The aim of the research is the introduction of new techniques that enable a visual comparison of scan-paths. Every eye tracking experiment produces many scan-paths, and one of the main challenges of eye tracking analysis is how two compare these scan-paths. A classic solution is to extract easily measurable features such as fixation durations or sa...

Eye movement is one of the biological signals whose exploration may reveal substantial information, enabling greater understanding of the biology of the brain and its mechanisms. In this research, eye movement dynamics were studied in terms of chaotic behavior and self-similarity assessment to provide a description of young, healthy, oculomotor sys...

Analysis of eye movement has attracted a lot of attention recently in terms of exploring areas of people’s interest, cognitive ability, and skills. The basis for eye movement usage in these applications is the detection of its main components—namely, fixations and saccades, which facilitate understanding of the spatiotemporal processing of a visual...

Proper calibration of eye movement signal registered by an eye tracker seems to be one of the main challenges in popularizing eye trackers as yet another user-input device. Classic calibration methods taking time and imposing unnatural behavior on eyes must be replaced by intelligent methods that are able to calibrate the signal without conscious c...

Proper calibration of eye movement signal registered by an eye tracker seems to be one of the main challenges in popularizing eye trackers as yet another user input device. Classic calibration methods taking time and imposing unnatural behavior of users have to be replaced by intelligent methods that are able to calibrate the signal without conscio...

There is much research indicating that eye tracking methods are a promising approach which can be used in revealing experts’ visual patterns and acquiring information regarding their subconscious behaviour while making decisions in professional tasks. The studies presented in this paper extend the aforementioned investigations and were aimed at che...

The aim of this research was to compare visual patterns while examining radiographs in groups of people with different levels and different types of expertise. Introducing the latter comparative base is the original contribution of these studies. The residents and specialists were trained in medical diagnosing of X-Rays and for these two groups it...

With growing access to cheap low end eye trackers using simple web cameras, there is also a growing demand on easy and fast usage of this devices by untrained and unsupervised end users. For such users the necessity to calibrate the eye tracker prior to its first usage is often perceived as obtrusive and inconvenient. In the same time perfect accur...

The eye movement analysis undertaken in many research is conducted to better understand the biology of the brain and oculomotor system functioning. The studies presented in this paper considered eye movement signal as an output of a nonlinear dynamic system and are concentrated on determining the chaotic behaviour existence. The system nature was e...

Recently eye tracking has become a popular technique that may be used for variety of applications starting from medical ones, through psychological, analyzinguser experience, ending with interactive games. Video based oculography (VOG) is the most popular technique because it is non-intrusive, can be use in users’ natural environment and are relati...

This paper presents the first attempt to fuse two different kinds of behavioral biometrics: mouse dynamics and eye movement biometrics. Mouse dynamics were collected without any special equipment, while an affordable The Eye Tribe eye tracker was used to gather eye movement data at a frequency of 30 Hz, which is also potentially possible using a co...

Vision plays a crucial role in children’s mental development. Therefore, early diagnosis of any vision disparities and implementation of a correct therapy is very important. However, carrying out such a procedure in case of young children and especially children with brain dysfunctions poses some limitations due to cooperation problems. The vision...

Most naturally-occurring physical phenomena are examples of nonlinear dynamic systems, the functioning of which attracts many researchers seeking to unveil their nature. The research presented in this paper is aimed at exploring eye movement dynamic features in terms of the existence of chaotic nature. Nonlinear time series analysis methods were us...

Eye tracking has become a valuable way for extending knowledge of human behavior based on visual patterns. One of the most important elements of such an analysis is the presentation of obtained results, which proves to be a challenging task. Traditional visualization techniques such as scan-paths or heat maps may reveal interesting information, non...

Eye tracking is an increasingly popular technique that may be used for a variety of applications including user experience analysis, usability engineering and interactive games. Moreover, this technique may be useful inter alia in education, psychological tests and medical diagnosis. Video-based oculography (VOG) is the most commonly utilized techn...

The aim of the study was to assess if dental imperfections influence scan-paths recorded during eye tracking sessions of naive observers. The participants observed 15 faces with 8 of them having various dental imperfections. All observations were recorded using an eye tracking device and spatio-temporal information about gaze positions was stored....

The performance and quality of medical procedures and treatments are inextricably linked to technological development. The application of more advanced techniques provides the opportunity to gain wider knowledge and deeper understanding of the human body and mind functioning. The eye tracking methods used to register eye movement to find the direct...

Eye tracking becomes more and more important way to analyze human behavior. However, a proper analysis of data obtained from an eye tracker occurs to be a challenging task. Traditional visualiza-tion techniques like scanpaths or heat maps may reveal interesting information, however much of useful information is still not visible , especially when t...

Eye movement is one of the key biological signals through which further analysis may reveal substantial information enabling greater understanding the biology of the brain and its mechanisms. Several methods for such signal processing have been developed, however new solutions are being continuously sought. This paper presents analysis of one of th...

Children affected by brain disabilities require a lot of attention and care to improve their life. The quicker the support will be introduced the better effect can be achieved. One of important impairments resulted from the brain disability is a cerebral visual one. In case of children, communicating with whom is difficult or impossible, assessment...

The paper describes research on ways of datasets discretization, when test datasets are used for evaluation of a classifier. Three different approaches of processing for training and test datasets are presented: “independent”—where discretization is performed separately for both sets assuming that the same algorithm parameters are used; “glued”—whe...

The paper presents studies on the application of the dissim-ilarity matrix-based method to the eye movement analysis. This method was utilized in the biometric identification task. To assess its efficiency four different datasets based on similar scenario ('jumping point' type) yet using different eye trackers, recording frequencies and time interv...

It is well known that eye movement tracking may reveal information about human intentions. Therefore, it seems that it would be easy to use gaze pointing as a replacement for other traditional human computer interaction modalities like e.g. mouse or trackball, especially when there are more and more affordable eye trackers available. However, it oc...

The paper presents the results of an initial experiment aimed to check if it is possible to enhance a low vision stimulation intervention with interactive games. There were 35 children with normal vision and various vision deficits examined using three different interactive games. The interactivity was achieved with the usage of an eye tracker—a de...

The paper presents the algorithm supporting an implicit calibration of eye movement recordings. The algorithm does not require any explicit cooperation from users, yet it uses only information about a stimulus and an uncalibrated eye tracker output. On the basis of this data, probable fixation locations are calculated at first. Such a fixation set...

In this paper we apply two data dimensionality reduction methods to eye movement dataset and analyse how the feature reduction method improves classification accuracy. Due to the specificity of the recording process, eye movement datasets are characterized by both big size and high-dimensionality that make them difficult to analyse and classify usi...

Biometric identification is a very popular area of interest nowadays. Problems with the so-called physiological methods like fingerprints or iris recognition resulted in increased attention paid to methods measuring behavioral patterns. Eye movement based biometric (EMB) identification is one of the interesting behavioral methods and due to the int...

Eye movement may be regarded as a new promising modality for human computer interfaces. With the growing popularity of cheap and easy to use eye trackers, gaze data may become a popular way to enter information and to control computer interfaces. However, properly working gaze contingent interface requires intelligent methods for processing data ob...

Acquiring basic information about the user’s needs, is one of the most important problem which a user interface designer has to face. It influences the selection of the design patterns which match the user’s requirements. Most frequently lots of possible solutions could be found and the appropriate choice has to be done. The results from some previ...

The research currently conducted in various fields of interest base their experiments on the eye movement signal analysis. Among these areas cognitive studies on people’s willingness, intentions or skills and advanced interface design can be enumerated. There are also some studies attempting to apply the eye tracking in security tasks and biometric...

There are many studies which discuss the problem of using various NoSQL databases and compare their efficiency thus confirming their usefulness and performance quality. However, there are very few studies dealing with the problem of replacing data storage for systems currently working. This lack has become a motivating factor to examine how difficu...

Eye movement is a new emerging modality in human computer interfaces. With better access to devices which are able to measure eye movements (so called eye trackers) it becomes accessible even in ordinary environments. However, the first problem that must be faced when working with eye movements is a correct mapping from an output of eye tracker to...

The idea concerning usage of the eye movement for human identification has been known for 10 years. However, there is still lack of commonly accepted methods how to perform such identification. This paper describes the second edition of Eye Movement Verification and Identification Competition (EMVIC), which may be regarded as an attempt to provide...

The analysis of an eye movement signal, which can reveal o lot of information about the way human brain works, has recently attracted the attention of many researchers. The basis for such studies is data returned by specialized devices called eye-trackers. The first step of their usage is a calibration process, allowing to reflect an eye position t...

PINs are one of the most popular methods to perform simple and fast user authentication. PIN stands for Personal Identification Number, which may have any number of digits or even letters. Nevertheless, 4-digit PIN is the most common and is used for instance in ATMs or cellular phones. The main ad-vantage of the PIN is that it is easy to remember a...

Dynamic development of high quality cameras and algorithms processing eye movement signals entails growing interests in using them in various areas of human-computer interaction. Determining subjects which user is looking at or controlling the operation of computer processes can serve as examples of these areas. However, making eye movement signal...

Eye movement data may be used for many various purposes. In most cases it is utilized to estimate a gaze point - that is a place where a person is looking at. Most devices registering eye movements, called eye trackers, return information about relative position of an eye, without information about a gaze point. To obtain this information, it is ne...

Nowadays, many database administrators come across problems regarding storing big amount of data. On the one hand there are made demands of improving of data access efficiency but on the other hand, ways of a storage cost reduction are searched for. One of popular approaches to enhancing database systems is using virtualization technologies. They d...

The possibility of using MOODLE e-learning platform as an environment for teaching database issues, concerning database objects and users creating, analysis and management of a transaction has been analyzed in the paper. All of the needed extensions were made using PHP scripts and were tested in the chosen database servers: MySQL, SQL Server and Or...

Data replication is one of the ways to fulfil growing expectations of computer systems end users. It allows to improve reliability and performance of software solutions. On the other hand, multiagent systems is acomputation model which may facilitate an exploit of large distributed systems potential. Combination of both mechanisms gives new possibi...

Considerations presented in the paper regard issues concentrating on building systems that use agent technology for distributed data management. In the designed system architecture, two main types of agents can be found: the stationary ones, which act in given nodes, and mobile ones that can move among system nodes. During the research, attention w...

The problem of database issues teaching with usage of Internet tools was discussed in the paper. For this purpose the database knowledge and groups of course trainees were categorized. It has influenced the construction of a database e-learning course for which the module structure has been proposed. The designed course was implemented to the MOODL...

The issue of database schemas comparison and integration has been discussed in this paper. The research was connected with problems of database schemas integration that are maintained by various database management systems. This operation is often realized in programmers’ group work as well as in database administrators’ duties. Automation of this...

The project and the implementation of replicated data management mechanisms, dedicated to systems operating in distributed environment, were described in this article. The user-defined logic presented in the paper is a part of the bigger distributed system that uses replication and is an example of using different user-defined algorithms. The aim o...