Grzegorz Redlarski

Gdansk University of Technology · Department of Mechatronics and High Voltage Engineering

The paper presents the methods of assessing the technical condition of varistor surge arresters used in laboratory tests and in operation—performed without disconnecting the arresters from the network. The analysis of the diagnostic methods was supplemented with the results of the measurements of the leakage current of arresters coming directly fro...

The paper presents the methods of assessing the technical condition of varistor surge arresters used in laboratory tests and in operation - performed without disconnecting the arresters from the network. The analysis of diagnostic methods was supplemented with the results of measurements of the leakage current of arresters coming directly from prod...

Harmful Internet use (HIU) describes unintended use of the Internet. It could be both self-harm and harming others. Our research goal is to develop a more accurate method for measuring HIU by this novel peer assessment. As such, it may become, with our call for more research, a paradigm shift supplementing every rating scale or other type of Intern...

In this paper, a new method for analysing gastroesophageal reflux disease (GERD) is shown. This novel method uses wavelet transform (WT) and wavelet-based fractal analysis (WBFA) on esophageal pH-metry measurements. The esophageal pH-metry is an important diagnostic tool supporting the physician’s work in diagnosing some forms of reflux diseases. I...

Continuous work on a new generation of actuators, referred to as artificial muscles, resulted in the initiation of work on electrostatic zipping actuators, the concept of which is derived from micro electro-mechanical devices. Despite partial knowledge of their basic operating parameters, a question remains whether electrostatic zipping actuators a...

The diagnostics of the condition of athletes has become a field of special scientific interest and activity. The aim of this study was to verify the effect of a long (100 km) run on a group of runners, as well as to assess the recovery time that is required for them to return to the pre-run state. The heart rate (HR) data presented were collected t...

Using robotics in modern medicine is slowly becoming a common practice. However, there are still important life science fields which are currently devoid of such advanced technology. A noteworthy example of a life sciences field which would benefit from process automation and advanced robotic technology is rehabilitation of the upper limb with the...

This article presents a method for selecting the elements of a C-type filter working with a conventional LC-type filter for compensating reactive power and filtering out higher harmonics generated by arc furnaces and ladle furnaces. The study was conducted in a steel mill supplied by a 110 kV transmission system, where higher harmonic currents and...

Background: The purpose of this study was to analyze hemodynamic changes in patients treated with percutaneous coronary intervention (PCI) at an early stage of acute myocardial infarction (AMI) and at one-month follow-up. Methods: Patients with AMI (n = 27) who underwent PCI were analyzed using impedance cardiography (ICG). ICG data were collect...

The subject of human-hand versatility has been intensively investigated for many years. Emerging robotic constructions change continuously in order to mimic natural mechanisms as accurately as possible. Such an attitude is motivated by the demand for humanoid robots with sophisticated end effectors and highly biomimic prostheses. This paper provide...

This paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequenc...

Musculoskeletal disorders can completely take away the possibility of one’s locomotion, and in most cases require intensive rehabilitation. Medical services are still one of the least automated, while in the era of increasing emphasis on personalized medicine, the only effective way to overcome most problems can be to automate the rehabilitation pr...

Compelling evidence against a heedless group theory generalization of pairwise comparisons elements is provided by means of counterexamples and mathematical reasoning. The lack of acceptable semantics for selected groups (with negative and complex numbers) and implications are analyzed. This study also provides examples and mathematical reasoning i...

Compelling evidence against a heedless group theory generalization of pairwise comparisons elements is provided by means of counter-examples and mathematical reasoning. The lack of acceptable semantics for selected groups (with negative and complex numbers) and implications are analyzed. This study also provides examples and mathematical reasoning...

This work presents basic information associated with markets of selected alternative fuels used in transport, such as methyl esters, conventional bioethanol and lignocellulosic bioethanol, and the market of electrical vehicles. Legal conditions, which stimulate development and regulate the mode of functioning of the liquid biofuel market until 2020...

This paper presents a new approach to computer supported esophageal pH-metry measurement analysis performed in order to diagnose gastroesophageal reflux disease. In this approach wavelet analysis was used to analyse the esophageal pH-metry course. The research was performed on three groups of pH-metry courses: whole 24-hour pH-metry course, sleep o...

Body surface area (BSA) may be computed using a variety of formulas, but the computed BSA differs from real BSA values for particular subjects. This is presented in the paper by computing BSA values for selected subject and comparing them to the real BSA value obtained with the use of a 3D body scanner. The results show ine-qualities in the relevan...

The article introduces a comparative analysis of existing methods for calculation of forearm and palm skin surfaces with high quality 3D models. Moreover, it was possible to systematize the errors resulting from these calculations and their division due to the BMI of a person. For people with BMI below 20, a maximum error of 8.5% was found, while f...

Overarching objective of this paper is classification of basic hand gestures by surface electromyography for healthy children. Main difference between biosignals corresponding to adults and children muscle activity is disparate growth of muscles. For this reason youngsters need separate method of signals classification. In this paper we decide to c...

Bioethanol is a liquid fuel for which a significant increase in the share of energy sources has been observed in the economies of many countries. The most significant factor in popularizing bioethanol is the profitability of investments in construction of facilities producing this energy source, as well as the profitability of its supply chain. Wit...

The paper presents a comparison of four optimisation algorithms implemented for the purpose of finding the shortest path in static and dynamic environments with obstacles. Two classical graph algorithms — the Dijkstra complete algorithm and A* heuristic algorithm — were compared with metaheuristic River Formation Dynamics swarm algorithm and its ne...

Body surface area (BSA) may be computed using a variety of formulas, but the computed BSA differs from real BSA values for particular subjects. This is presented in the paper by computing BSA values for selected subject and comparing them to the real BSA value obtained with the use of a 3D body scanner. The results show inequalities in the relevant...

Body surface area (BSA) plays a key role in several medical fields, including cancer chemotherapy, transplantology, burn treatment and toxicology. BSA is often a major factor in the determination of the course of treatment and drug dosage. A series of formulae to simplify the process have been developed. Because easy-to-identify, yet general, body...

The paper is accepted for publication in the Special Issue of Fundamenta Informaticae: on Theory and Practice of Pairwise Comparison. This study has been inspired by numerous requests for clarification from researchers who often confuse Saaty's Analytic Hierarchy Process (AHP) with the pairwise comparisons (PC) method, taking AHP as the only repres...

This study has been inspired by numerous requests for clarification from researchers who often confuse Saaty's Analytic Hierarchy Process (AHP) with the pairwise comparisons (PC) method, taking AHP as the only representation of PC. This study should be regarded as an interpretation and clarification of past investigations of PC. In addition, this a...

This paper presents an innovative classification system for hand gestures using 2-channel surface electromyography analysis. The system developed uses the Support Vector Machine classifier, for which the kernel function and parameter optimisation are conducted additionally by the Cuckoo Search swarm algorithm. The system developed is compared with...

Current technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. The harm caused by this pollution is still open to question since there is no...

The esophageal pH-impedance examination is one of the most popular diagnostic methods for identifying the upper gastrointestinal tract’s diseases. Inconclusive test evaluation criteria makes it difficult to state the definite diagnosis. In this paper, the computer platform supporting the research and teaching process in the area of pH-impedance ana...

This work presents results of the primary energy use for heating residential single-family house. Analysis includes domestic hot water system (DHW) and heating, ventilation and air condition system (HVAC). During researches the conventional and alternative energy sources (natural gas, biomass, fuel oil, bituminous coal, lignite, or electric energy...

These paper presents research results of muscle EMG signal denoising. In the same time two muscles were examined - an adductor muscle (biceps brachii) and an abductor muscle (tricpeps brachii). The EMG signal was filtered using the wavelet transform technique, having selected the crucial parameters as: wavelet basis function (Daubechies 4), 10th de...

The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases – one of the major causes of death around the globe – a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement...

Adaptacyjny algorytm filtracji sygnału fonokardiograficznego wykorzystujący sztuczną sieć neuronową Streszczenie. Podstawowym problemem podczas projektowania systemu autodiagnostyki chorób serca, bazującego na analizie sygnału fonokardiograficznego (PCG), jest konieczność zapewnienia, niezależnie od warunków zewnętrznych, sygnału o wysokiej jakości...

The main obstacle in development of intelligent autodiagnosis medical systems based on the analysis of phonocardiography (PCG) signals is noise. The noise can be caused by digestive and respiration sounds, movements or even signals from the surrounding environment and it is characterized by wide frequency and intensity spectrum. This spectrum overl...

This paper presents a model of alveolar-capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differential equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen...

Due to a significant rise in the number of patients diagnosed with diseases of the upper gastrointestinal tract and the high cost of treatment, there is a need to further research on one of the most popular diagnostic tests used in this case – esophageal Multichannel Intraluminal Impedance and pH measurement. This may lead to finding new diagnostic...

One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic fie...

In the face of increasingly stringent pollutant emission regulations, designing an agricultural holding becomes a difficult challenge of connecting a large number of coefficients that describe an energy system of a farm in regard to its ecological and economic efficiency. One way to cope with this issue is to design an energy self-sufficient farm t...

In this paper a new classification algorithm of phonocardiography signal is presented. It enables an effective identification of 12 different heart sounds. Through the combination of Linear Predictive Coding (LPC) algorithm and artificial neural network, an accuracy of 82% in identification of signals and 100% of precision in distinguishing between...

The article discusses issues related to bioethanol production in Poland in terms of the requirements of the EU. Also this paper presents models of research and decision-making model on the basis of which were completed survey among companies producing bioethanol, and the model recommended for the future. For the presented examples of companies prod...

This paper presents a new versatile approach to model severe human respiratory diseases via computer simulation. The proposed approach enables one to predict the time histories of various diseases via information accessible in medical publications. This knowledge is useful to bioengineers involved in the design and construction of medical devices t...

Recent scientific studies show the growing importance of the coefficients: BSA and TBSA, as an alternative to the widely used BMI. The relevant indicators are widely used in medicine, including such areas as: the treatment of burns, chemotherapy, dermatology and toxicology; as benchmarks when calculating doses of drugs and fluids. The particular pr...

River Formation Dynamics is a heuristic optimization algorithm based on the manner, in which drops of water form the river bed. The idea is to imitate the movement of drops on the edges between given nodes thus performing a search based on their height, which is modified through the mechanism of soil erosion and sediment deposition. In this way dec...

One of the important factors that affect the reliable operation of the power system and the rapid restitution after disaster is a quick and effective combining synchronous electric power facilities to operate in parallel [. Hence, diagnostics of automatic synchronizers at every stage of their life, from building a prototype, through the whole life,...

In many automatics and mechatronics systems accurate modeling of several physical processes is needed. In power system, one of these is the process of control of angular velocity of power blocks during their connection to parallel operation. This process is extremely dynamic and the response of control system results from continuous changes in many...

In the paper the behavior based control system of an autonomous mobile robot SCORPION is presented to execute the one of the most difficult navigation task, which is the complete coverage task of unknown area with static obstacles in the environment. The main principle assumed to design control system was that the robot should cover all area only o...

Optical glyphs are non-complex graphic signs that contain encoded information. By utilizing techniques of image processing and pattern recognition, it is possible to implement an effective global system for autonomous vehicle navigation. The simplicity of the system allows it to be easily implemented, without having to rebuild monitoring equipment....

The paper presents a description of functioning of a platform supporting the detection of obstructive diseases in the respiratory system education process. A 16-parameter model of the respiratory system simulated in the Matlab/Simulink environment was set in the role of the tested patient. It has been linked to the control layer, developed in the L...

Our paper discusses a scenario for adapting residential buildings to the requirements of the EU climate and energy package. It analyzes the option of reducing pollutant emissions to ambient air by switching to alternative energy sources in a typical single-family residential building. The most common sources of energy in central heating and ventila...

Since the beginning of the development of exoskeletons in the early 1960s there was a constant need for improving their actuators technology. Requirements for high power and torque for the lower body and very high precision for the hand motion, while maintaining the flexibility of biological muscles, are still not fully satisfied. The problem lies...

This paper presents the results of simulation and experimental tests connected with changing the connecting angle during synchronization of electrical power units. Obtained, normal probability distributions form the basis for assessing likelihood an assumed value of angle in real condition at work. These results are very important during developmen...

In the paper author has presented a new methods of compensation of angular acceleration, relevant to aligning the frequency of voltage of the joined electrical objects. The error of these methods, their advantages and disadvantages has been presented. Moreover these methods constitute one of the factors to increase power system reliability and quic...

In the paper author has presented a new method of synchronisation in dynamic state, relevant to aligning the frequency of voltage of the joined objects. The method allows for multiple reductions of time of the synchronisation and can be used in situations which require speed i.e. situations which cause blackout.

Robotics is actually one of the most important technologies; which in the last year has been developing very fast. It’s interdisciplinary since combine mechanics, automatic, electric, and computer since. This paper presents generally the problems in navigation which should be solved by all who wants to build such educational and mobile robots [1, 3...

In paper the methodology of complete coverage of unknown area by autonomous mobile robot is described. The main principles of complete coverage task using sensory data only are given. The shape of coverage area is defined. The modified "the way of the ox" algorithm is proposed to realize this task and its following stages are described. Definitions...

In this paper the identification method of the parameter representing the inertia of masses flowing water throw the pipes in water power plants has been presented. The value of this parameter is used in adaptable method of synchronizing power generators. The identification based on the simplified mathematical model of the hydro-turbine and initial...

The main goal of this article is to compare the accuracy of the extrapolations time phase coincidence for the selected methods. In the comparing analysis selected the method using calculable function, polynomial function and linear function. The general idea of synchronization proceed in electrical power system is presented. The most important work...

In this paper the authors present the localization system which uses triangulation and trilateration to position mobile robot in the two-dimensional space. Distance was measured with the strength of radio signal emitted by devices of existing communication network, which were constructed by the authors. To get the actual distance in the function of...

In this paper essence of synchronization methods and block scheme of realized simulator of synchronization methods and algorithms for research work have been presented. At first hardware and software of simulator and their connection with synchronization orocess have been described. After that a practical usage of simulator and range of possibiliti...

In this paper mathematical models of control systems used to tets of methods and alghoritms in synchronizaig electrical objects have been described. Moreover method of modyfikation of this models, which to take into consideration disturbance of response of real electrical objects in synchronizing process have been presented.

From many years automatic synchronizers in electric power system are used to combine electric power unit. This devices are very sophisticated in a point of view hardware and software. Incorrectly work of synchronizers can cause many consequences in electric power system. In this paper integrated of this problem with a functional safety has been pre...

In this paper selected problems of testing automatic synchronizers of power generators in the real time and real conditions at work has been presented. At first prototype of computer simulator to test automatic synchronizers in close loop has been presented. And then this device (controlled by dedicated computer) was describe and compare with a cla...

In the paper using the model of angle speed control unit in adaptive method of synchronizing power generators for water plant described. The identification of the selected parameters of the model and results of the simulation verification shown. As a final conclusion presented the model with identified parameters which are used to predict the time,...