ZASTOSOWANIE POTENCJAŁU LENNARD-JONESA DO MODELOWANIA RUCHU ROBOTÓW

The article proposes a method of controlling the movement of a group of robots with a model used to describe the interatomic interactions. Molecular dynamics simulations were carried out in a system consisting of a moving groups of robots and fixed obstacles. Both the obstacles and the group of robots consisted of uniform spherical objects. Interactions between the objects are described using the Lennard-Jones potential. During the simulation, an ordered group of robots was released at a constant initial velocity towards the obstacles. The objects’ mutual behaviour was modelled only by changing the value of the interaction strength of the potential. The computer simulations showed that it is possible to find the optimal value of the potential impact parameters that enable the implementation of the assumed robotic behaviour scenarios. Three possible variants of behaviour were obtained: stopping, dispersing and avoiding an obstacle by a group of robots.W artykule zaproponowano metodę kontrolowania ruchu grupy robotów za pomocą modelu stosowanego do opisu oddziaływań międzyatomowych. Przeprowadzono symulacje metodą dynamiki molekularnej w układzie składającym się z ruchomych grup robotów oraz nieruchomych przeszkód. Zarówno przeszkody, jak i roboty składały się z jednolitych sferycznych obiektów. Oddziaływania między obiektami opisano za pomocą potencjału Lennard-Jonesa. Podczas symulacji, początkowo uporządkowana grupa robotów poruszała się ze stałą prędkością w kierunku przeszkód. Wzajemne zachowanie obiektów modelowano tylko poprzez zmianę wartości parametrów potencjału oddziaływań. Symulacje komputerowe wykazały, że możliwe jest znalezienie optymalnych wartości parametrów oddziaływania, które umożliwiają uzyskanie pożądanego zachowania robotów. W trakcie symulacji uzyskano trzy możliwe warianty zachowania: zatrzymywanie, rozpraszanie i omijanie przeszkód przez grupę robotów

Comparative analysis of selected programs for optical text recognition

The aim of the article is to compare three programs for the optical text recognition. The problem of the optical text recognition has been defined. Next, briefly the functionality of this technology was described. The most important programs realizing the discussed problem were also characterized. The selected programs were tested using two samples of machine writing in Polish. The speed of the text recognition process was determined. The correctness of characters and words recognition in the analyzed text was also specified

ANALIZA STOSOWALNOŚCI USŁUG SIECIOWYCH TYPU REST I SOAP

Web Services are common means to exchange data and information over the network. Web Services make themselves available over the Internet, where technology and platform are independent. These web services can be developed on the basis of two interaction styles such as Simple Object Access Protocol (SOAP) and Representational State Transfer Protocol (REST). In this study, a comparison of REST and SOAP web services is presented in terms of their applicability in diverse areas. It is concluded that in the past both technologies were equally popular, but during the rapid Internet development the REST technology has become the leading one in the area of access to Internet services.Usługi sieciowe są powszechnie stosowane do wymiany danych i informacji w Internecie. Usługi sieciowe nie zależą od użytej platformy sprzętowej oraz od oprogramowania. W niniejszym artykule zostały omówione dwie najpopularniejsze technologie tworzenia usług sieciowych: REST (ang. Representational State Transfer) i SOAP (ang. Simple Object Access Protocol). W trakcie realizacji badań przeprowadzono analizę stosowalności  tych usług w różnych obszarach zastosowań. Stwierdzono że w przeszłości obie technologie cieszyły się porównywalną  popularnością, lecz w momencie gwałtownego rozwoju Internetu technologia REST stała się technologią dominującą w zakresie dostępu do usług sieciowych

Effect of Nanoindentation Rate on Plastic Deformation in Cu Thin Films

The paper investigates the nanoindentation process with different rates in the Cu (001) of FCC system. The indentation process was done using molecular dynamics simulation based on the embedded atom method theory and Morse potential. Simulation process of indentation used a rigid spherical indenter with the diamond structure. To structure characterization we applied the adaptive common neighbour and the dislocation extraction analysis. It was found that the range of the linear change of the indentation force depends on the rate of response of the system. The initial range of the linear dependence of stress evolution also depends on the rate of indentation. Moreover, the average total normal stress in the system is only compressive. After linear changes, we observe oscillating changes in stress evolution. During indentation, for the range of linear changes of stress, dislocations aggregated only around the indenter surface. The creation of dislocations is directly connected with the structural changes. The structure analysis revealed the formation of HCP and BCC structure in the Cu (001) of FCC systems and a correlation with the creation of dislocations

Comparative analysis of selected programs for optical text recognition

Celem artykułu jest porównanie trzech programów do optycznego rozpoznawania teksu. Zdefiniowany został problem optycznego rozpoznawania tekstu i przedstawione główne jego zastosowania. Opisano działanie tej technologii i krótko scharakteryzowano najważniejsze dostępne na rynku programy realizujące omawiane zagadnienie. Następnie poddano testom wybrane programy wykorzystując dwie próbki pisma maszynowego w języku polskim. Określono szybkość procesu rozpoznawania tekstu. Poprawność rozpoznania znaków i wyrazów w analizowanym tekście została także określona.The aim of the article is to compare three programs for the optical text recognition. The problem of the optical text recognition has been defined. Next, briefly the functionality of this technology was described. The most important programs realizing the discussed problem were also characterized. The selected programs were tested using two samples of machine writing in Polish. The speed of the text recognition process was determined. The correctness of characters and words recognition in the analyzed text was also specified

Estimation of the Path-Loss Exponent by Bayesian Filtering Method

Regarding wireless sensor network parameter estimation of the propagation model is a most important issue. Variations of the received signal strength indicator (RSSI) parameter are a fundamental problem of a system based on signal strength. In the present paper, we propose an algorithm based on Bayesian filtering techniques for estimating the path-loss exponent of the log-normal shadowing propagation model for outdoor RSSI measurements. Furthermore, in a series of experiments, we will demonstrate the usefulness of the particle filter for estimating the RSSI data. The stability of this algorithm and the differences in determined path-loss exponent for both method were also analysed. The proposed method of dynamic estimation results in significant improvements of the accuracy of RSSI values when compared with the experimental measurements. It should be emphasised that the path-loss exponent mainly depends on the RSSI data. Our results also indicate that increasing the number of inserted particles does not significantly raise the quality of the estimated parameters

Recognition of handwritten Latin characters with diacritics using CNN

Convolutional Neural Networks (CNN) have achieved huge popularity in solving problems in image analysis and in text recognition. In this work, we assess the effectiveness of CNN-based architectures where a network is trained in recognizing handwritten characters based on Latin script. European languages such as Dutch, French, German, etc., use different variants of the Latin script, so in the conducted research, the Latin alphabet was extended by certain characters with diacritics used in Polish language. To evaluate the recognition results under the same conditions, a handwritten Latin dataset was also developed. The proposed CNN architecture produced an accuracy of 96% for the extended character set. This is comparable to state-of-the-art results found in the domain of identifying handwritten characters. The presented approach extends the usage of CNN-based recognition to different variants of the Latin characters and shows it can be successfully used for a set of languages based on that script. It seems to be an effective technique for a set of languages written using the Latin script