Piotr Napieralski

Lodz University of Technology · Faculty of Technical Physics, Information Technology and Applied Mathematics

There is no doubt that society will not turn back: most thermal vehicles will switch to electric ones, not only for cars but also for bigger vehicles. Fast chargers will become more and more essential parts of the global system, they will provide a charge control of batteries and galvanic insulation from the grid. At the present times, compact real...

The paper proposes a simple structure of high−power solid−state transformers (SSTs) able to control the energy flow in critical lines of the medium−voltage (20 kV) distribution grid. With an increasing number of renewable intermittent sources connected at the nodes of the meshed distribution grid and a reduced number of nodes connected to large pow...

The monograph TEWI 2021 is a direct response to the demand of the industry, which looks for research projects partners. On the one hand, the material submitted for this monograph will give opportunity for the academic community to present their competencies in the thematic areas of research they conduct. On the other hand, the industry will stimula...

This work contains a solution improvement for Smart Events, which are one of the ways to guide the behavior of NPCs in computer games. The improvement consists of three aspects: introducing the possibility of group actions by agents, i.e. cooperation between them, extending the SE with the possibility of handling ordinary events not only emergency,...

The green energy transition is associated with the use of a wide range of metals and minerals that are exhaustible. Most of these minerals are limited in access due to small resource fields, their concentration in several locations and a broader scale of industry usage which is not limited exclusively to energy and environmental sectors. This artic...

Purpose: The literature suggests that rumination (i.e., repetitive thinking about 1 or more negative concerns that is perceived as difficult to control) is linked to impaired emotional regulation and increases negative affect. Not only individuals suffering from overweight or obesity, but also healthy individuals might use emotional eating as a co...

Emotions are commonly considered to be the most expressive of everyday human experiences, giving a sense of fullness and reality of life. The ability to recognize human emotions as a manifestation of higher intelligence is desirable feature. There are several models of emotional experience that can become the basis for building a universal emotiona...

The article proposes an analysis of the possible architectures of synchronous machines with an ability to operate at high temperatures of over 200°C in their environment. Two machine principles have been considered: the permanent magnet synchronous machine and the synchronous reluctance machine. The numerical analyses are carried out with 3D-couple...

A new approach is proposed for designing coils free of partial discharges (PDs) for compact machines operating at high altitudes. The proposed method consists in using an enameled wire made with a thin additional resistive layer on the outer surface, which reduces strongly the electrical field in the voids between the wires of random coils. With su...

The paper presents the design of a machine that can work at high temperature. The impact of various topologies and materials on electromagnetic field distribution and losses was analyzed. Two and three-dimensional simulations were carried out. The results obtained were discussed.

The subject of the paper is a three-dimensional analysis of a coupled fluid-thermal and electromagnetic field in permanent magnet synchronous machine that can work at very high temperatures. To obtain the distribution of the airflow and temperature we employed the coupled fluid-thermal model of the machine. This allowed us to check whether the temp...

The aim of this paper is to present methods for human eye blink recognition. The main function of blinking is to spread tears across the eye and remove irratants from the surface of the cornea and conjuctiva. Blinking can be associated with internal memory processing, fatigue or activation in central nervous system. There are currently many methods...

The aim of this paper is to present methods to calculate pupil size based on various parameters, such as: luminance, age, corneal flux density or monocular/binocular effect. These models allow to distinguish pupil dilation caused by the influence of light and other factors such as psychological state of participants.The developed methods were prese...

In recent years, computer simulations have become an innovative approach which enables research in the field of highly complicated physical phenomena and the study of the laws which govern the universe. The proper interpretation of the results of a visual simulation requires the highest quality of the generated image, as every distortion or mistake...

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program inclu...

The "Computer Game Innovations" series is an international forum made to enable exchange of knowledge and expertise in the field of video games development. Comprising both academic research and industrial needs, the series aims at advancing innovative industry-academia collaboration. The monograph provides a unique set of articles presenting origi...

This article presents a method for optimizing the design parameters of a twisted conductor to increase a cable's conductivity and reduce its weight. This, in turn, can preserve the conductive material. An automated procedure for linking an optimization algorithm implemented in a MATLAB environment with the commercial finite-element code Abaqus for...

Purpose Technological innovation has made it possible to review how a film cues particular reactions on the part of the viewers. The purpose of this paper is to capture and interpret visual perception and attention by the simultaneous use of eye tracking and electroencephalography (EEG) technologies. Design/methodology/approach The authors have...

Perspective projection is a type of rendering that makes the images of three-dimensional objects approximate actual visual perception. The change of the field of view feature makes the camera switch to an either wider or narrower lens. The wide angle of virtual cameras in computer games, as well as in computer animation, can give a particular cinem...

Virtual reality (VR) has become popular both in visualization and as a tool in various supportive therapies. Many types of therapies using virtual reality can be distinguished, among them immersion therapy (VRIT) and simulation for therapy (SFT). Patients receiving virtual reality therapy navigate through digitally created environments and complete...

This paper presents the brief description of the robust method enabling correction of high-resolution stereograms. The algorithm allows to quickly detect and estimate the values of stereoscopic anomalies. such as vertical disparity, rotation and scale. The determined values used in the process of image transformation enable to correct stereogram an...

Main changes in pupile size, contractions and dilatation, are coused by light. Because other criteria like general arousal, cognitive processes or even memory operations can affect changes in pupil, decupling of light is important. Pupil size is controlled by group of iris muscles called sphinicter pupillae and dilator pupillae. Those structures ar...

The visual saliency map is becoming important and challenging for many scientific disciplines (robotic systems, psychophysics, cognitive neuroscience and computer science). Map created by the model indicates possible salient regions by taking into consideration face presence and motion which is essential in motion pictures. By combining we can obta...

This paper identifies the major types of artifacts occurring in three-dimensional materials. It focuses on the analysis of vertical disparity. The vertical disparity is the artifact of the 3D images that appears both in the film material and in the computer visualizations. The research explains the causes and consequences of the vertical disparity...

This paper focuses on mobile systems that facilitate the social functioning of disabled people. It particularly describes innovative assistive applications intended for people with visual impairment. The study contains a brief description of face navigation process and tools allowing implementation of this issue in the Android environment. The resu...

The potential of BCI technology is used in scientific study of human perception and vision in medical and non-medical domains. In this paper we try to capture and interpret visual perception and attention in video movies by eye tracking and EEG technology simultaneously. Joint analysis of EEG and eye tracking offer new potentials for video analysis...

Non Player Characters play an important role in every video game, as they can act as competitors or allies of the playable character. NPCs that are able to react in a realistic fashion may contribute to creating a life-like and immersive virtual world. Thus, to improve the believability of such characters, emotion engines were developed. The presen...

Gaze motion research has started in 1879 when French ophthalmologist Louis Emile Javal came to a conclusion that observer does not sweep smoothly along the text with his eyes, but with a series of stops and quick saccades [3]. Since his first observation, the eye-tracking devices were developed. Firstly readers had to wear a type of contact lens wi...

Computer programs used for three-dimensional visualizations of phenomena occurring within the electromagnetic field do not have built-in diagnostic tools allowing to verify the quality of the obtained view. The image presented during the simulation may contain a variety of artifacts. The anomaly most often identified in three-dimensional images is...

The realistic simulation of cloths is nowadays a key to produce good-quality, authentic graphical visualizations of various cloth, such as characters garment elements, flags or curtains. This can be computationally expensive, more and more as number of particles, which cloth is divided into, increases. The solution to this matter was to use GPU (Gr...

Visual saliency modeling is becoming important and challenging for many scientific disciplines (robotic systems, psychophysics, cognitive neuroscience and computer science). Proposed model indicates possible salient regions by taking into consideration face presence and motion which is essential in motion pictures. By combining face presence and mo...

The "Computer Game Innovations" series is an international forum designed to enable the exchange of knowledge and expertise in the field of video game development. Comprising both academic research and industrial needs, the series aims at advancing innovative industry-academia collaboration. The monograph provides a unique set of articles presentin...

In this paper, we present the streamed photon mapping method for enhancing the rendering of caustics. In order to achieve a realistic caustic effect, global illumination methods require additional data, which are gathered by creating a caustic map or increasing the number of samples used for rendering. Our method employs a stream of photons with a...

Since the beginning of computer era we are trying to modeling nature. The results of these attempts are mathematical equations describing weather, snow flakes, plants growth or influence of species in individual biomes. In computer graphics fractal structures are often used because equations de- scribing them are very simple. Those forms are common...

This article focuses on different causes of visual discomfort and presents methods that can evaluate and improve the quality of VR applications. Chap- ters elaborate on stereoscopy, different saliency map elements (2D image saliency, depth saliency and visual comfort based saliency) and visual com- fort assessment. Differences between several salie...

This paper comprehensively describes the disparity effect occuring in three-dimensional scenes implementing virtual reality. It describes the true nature of analysed problem and identifies the major factors that cause the anomaly in stereoscopic images. The developed algorithm is the final effect of theoretical deliberating. It enables detecting di...

Purpose The purpose of this paper is to determine the physical design parameters that influence the total resistance of a twisted conductor (cable). One of the physical parameters characterizing this type of structures is the uneven distribution of resistivity due to hardening, which is the result of stress exerted on the wires during the manufactu...

Physically based rendering is not a new concept and it has been pursued in the scientific fields for a long time. However, it has not been until recently that the new generation of game consoles allowed more expensive algorithms to be adapted and computed in real-time constraints. In this paper, we analyse methods of approximating the lighting rece...

In this paper, we propose a method of 3D finite element analysis to predict the electrical behavior of a stranded cable. The performance of a conductor depends on the material it is made from, but also on its metallurgical condition and the electrical resistance of the inter-wires contact areas. A mechanical simulation of the wiring and compacting...

Stereoscopic films and interactive presentations are extensively popularized whereas their perceived quality still dissatisfies viewers. The reasons are shared between hardware inconsistencies and stereo image producers unawareness concerning factors influencing depth perception quality. This paper reviews aspects influencing 3D image perception vi...

The research on Streamed Photon Mapping method has shown its efficiency and potential. Significant caustic effects without an additional caustic map are its undeniable advantage. The method assumed that light spreads in a vacuum; however, such approach excluded the visualization of such phenomena as fog, smoke, or clouds. This paper presents a modi...

Medical rehabilitation treatment is of vital importance to all those who have experienced limb impairments due to unexpected accidents or geriatric dysfunctions. However, due to extensive government savings, the access to regular rehabilitation services is becoming increasingly difficult. This paper presents a low-cost, immersive augmented reality...

Multi-strand conductors exhibit lateral instabilities when loaded under compression and rotation. The stability and ability of current distribution is controlled by the transverse resistivity. It is mainly determined by the contact resistance at the strand crossovers and inter-strand contact resistance. The surfaces layer properties and in particul...

Stereoscopic films and interactive presentations are extensively popularized whereas their perceived quality still dissatisfies viewers. The reasons are shared between hardware inconsistencies and stereo image producers unawareness concerning factors influencing depth perception quality. This paper reviews aspects influencing 3D image perception vi...

Powtarzające się myśli negatywne (ruminacje) są jedną ze strategii regulacji emocjonalnej. Można je zdefiniować jako pasywne, abstrakcyjne analizowanie przyczyn, skutków i znaczenia przeszłej sytuacji lub stanu emocjonalnego. Piśmiennictwo przedmiotu wskazuje, że niektóre zaburzenia afektywne, jak depresja, charakteryzują się nadmiernym używaniem r...

This paper presents the analysis of partial methods for client-side object detection on Android platform. First issue of this work is to define the main restrictions related to client-side data processing in context of mobile devices. Then the study describes an object detection process and identifies elementary algorithm used for this task in Andr...

The project focuses on the use of modern technology to analyze human movement. This analysis turns out to be useful aid for physicians in rehabilitation of patients with limb injuries. This method is more precise than simple observation of the patient through the organ of sight. The proposed system allows markerless determination of deviations betw...

Monografia dr inż. Piotra Napieralskiego koncentruje się na metodach i algorytmach syntezy obrazów komputerowych, nazywanych algorytmami renderingu. Zawarto w niej zarówno przegląd badań z tej dziedziny prowadzonych na świecie, jak i wyniki badań Autora. Badania te dotyczą projektowania i implementacji nowych rozwiązań, umożliwiających skrócenie cz...

Purpose – The purpose of this paper is to find a more performing and automated procedure for linking an identification algorithm implemented in a general‐purpose environment with a commercial finite‐element code for magnetic field analysis. In particular, the use of a multiprocessor computer makes it possible to perform parallel computations keepin...

The study proposes an automated procedure for linking an identification algorithm implemented in a general-purpose environment (MatLab) with a commercial finite-element code for magnetic field analysis (VF-Opera). The method is used to identify the B-H curves of anisotropic magnetic laminations in the direction normal to the sheet surface with the...

This paper proposes the identification of the B-H curve of anisotropic magnetic laminations in the direction normal to the sheet surface. An automated procedure for linking an identification algorithm implemented in a Matlab environment with a commercial finite-element code Opera for 3-D magnetic field analysis has been used. In particular, an opti...

This paper presents several algorithms for high-performance rendering engines. In the first part we describe the development of global illumination methods with particular emphasis on photon mapping. Secondly, we present methods used by the rendering system design and consider the possibility of further developing these methods.

In this paper we present an interactive method for visualizing three-dimensional vector fields. We decided to apply dynamic particle system, which is directly connected with the values of magnetic field. We introduce a GPU implementation for the simulation stage and rendering stage of a dynamically magnetic fields particle system. The geometry of t...

Measurement of noise in the Monte Carlo point sampling method}, volume={59}, abstractNote={This paper gives a concise overview of the techniques we have used to find out the degree of measuring the quality of rendered images and a level of noise in particular. First part of the paper presents designed and conducted psychophysical experiment involvi...

This chapter covers the modeling of laminated structure made with grain-oriented electrical steel sheets. It introduced a homogenization technique which takes into account the anisotropy due to laminations rolling direction overlapping and the one due to the crystals orientation. The homogenization method is based on the minimization of energy. Tha...

This paper presents an algorithm for animation in global illumination environment for dynamic scenes illuminated by arbitrary, static light sources. Global illumination techniques are difficult to apply for the generation of photorealistic animations because of their high computational costs. These costs are so huge that they take many weeks of com...