The paper deals with the measurement of individual size components of particulate matter focusing on typical particle size, mass, and number concentrations primarily in the city of Košice (Slovak republic) and the surrounding countryside. The deployment of the sensor IPS-7100 in the 2nd half of December 2022 allowed us to measure the particles smaller than the detection limit of other low-cost optical sensors—namely SPS30 and SEN54. The results show that although the mass concentration of ultrafine particles is negligible in comparison to fine and coarse particles, in terms of number concentration ultrafine particles make up the dominant component of particulate matter, which stands as a warning from the health point of view.

Visuospatial functions play a crucial role in human cognition, which has elicited over years a great deal of research focusing on their assessment, training and restoration. Interestingly, although our visuospatial capacities allow us to understand and infer relationships of 3D objects in space, these 3D aspects of visuospatial processing are profoundly neglected in laboratory tests, and instead, 2D designs are commonly used. Aiming to increase the ecological validity of such tests, we propose an experiment to evaluate the capacity of a 3D virtual space to stimulate cognitive functions. The experiment involves cognitive testing, EEG measurements, and cognitively stimulating tasks in an immersive 3D virtual environment rendered by a unique CAVE system. This paper focuses primarily on two game prototypes that will serve as the virtual environment and describes a natural movement control using the Myo armband, incorporated into one of the games. We also briefly discuss cognitive testing design using the selected brain electrophysiological variables measured on human subjects before and after the virtual reality game use, in order to assess the potential effect of the game.

This chapter explores the essential role of game and graphics rendering engines in creating computer games and their applications in education. Starting with a brief discussion on the importance of visualization in game development, we analyze popular game engines, including CryEngine, Irrlicht, Unreal Engine, Unity, and Godot, and graphics rendering engines (cores), including OpenSceneGraph (OSG) and Object-Oriented Graphics Rendering Engine (OGRE). Each engines unique features and pedagogical potentials are discussed, with emphasis on Unity, Godot, and Unreal Engines interactive and step-by-step tutorials. This analysis reflects the adaptability of game engines to different teaching styles and provides insights into their effectiveness as tools for teaching game development and computer science. The chapter aims to highlight game engines role in game creation and education by exploring these topics.

COVID-19-related quarantine measures resulted in a significant increase of interest in online collaboration tools. This includes virtual reality (VR) or, in more general term, extended reality (XR) solutions. Shared XR allows for activities such as presentations, training of personnel or therapy to take place in a virtual space instead of a real one. To make online XR as accessible as possible, a significant effort has been put into the development of solutions that can run directly in web browsers. One of the most recognized solutions is the A-Frame software framework, created by Mozilla VR team and supporting most of the contemporary XR hardware. In addition, an extension called Networked-Aframe allows multiple users to share virtual environments, created using A-Frame, in real time. In this article, we introduce and experimentally evaluate three components that extend the functionality of A-Frame and Networked-Aframe. The first one extends Networked-Aframe with the ability to monitor and control users in a shared virtual scene. The second one implements six degrees of freedom motion tracking for smartphone-based VR headsets. The third one brings hand gesture support to the Microsoft HoloLens holographic computer. The evaluation was performed in a dedicated local network environment with 5, 10, 15 and 20 client computers. Each computer represented one user in a shared virtual scene. Since the experiments were carried out with and without the introduced components, the results presented here can also be regarded as a performance evaluation of A-Frame and Networked-Aframe themselves.

The paper presents LIRKIS CAVE, a Cave Automatic Virtual Environment, developed and built at the home institution of authors. The most significant features of LIRKIS CAVE are a compact and transportable design and use of LCD displays, organized in a decagon. The CAVE is described in terms of hardware and software and its performance is evaluated by a series of experiments. The paper also outlines future research and development activities related to the CAVE, which focus on the area of rehabilitation and education of handicapped people.