Wyniki wyszukiwania - BazTech

1

Asymmetric cryptosystem with random decomposition using fractional Fourier and Fourier transforms

Gaur Kapil Shankar, Singh Hukum, Thakran Seema

Optica Applicata

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2023

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Vol. 53, nr 4

591--602

EN

In this paper, an asymmetric cryptosystem based on random decomposition is proposed. The suggested scheme used three different decryption keys to get decrypted image, two of which are generated using phase truncation and one through random decomposition. The combination of these keys and fractional Fourier transform parameter increase the security of cryptosystem against various attacks. MATLAB simulations are used to validate the scheme’s conclusions. The effectiveness of a scheme is validated by the key sensitivity performance of the cryptosystem. This research also includes a 3D plot for both grayscale and binary images. Correlation coefficient (CC) values between the original and recovered images is also calculated to validate the cryptosystem.

2

Implementation of contactless angular speed measurement based on photo sensor

Abu Al Aish Amir, Salah Wael, Ahmad Mohammad, Alrashdan Mohd, Alsawalmeh Wael

Przegląd Elektrotechniczny

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2021

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R. 97, nr 3

80--83

EN

The main aim of this research is to propose a new and low cost angular speed measurement based on optical imaging technique. A photo sensor available in computer mouse is implemented as a contactless speed measurement transducer device. The photo mouse sensor output is used to convert the rotating speed of motor shaft, revolutions per minute (RPM), to linear speed. A software program written in C-sharp language is employed to determine the speed and display it in RPM. A motor with maximum rated speed of 2850 RPM is tested at different speeds. Performance comparison is founded by using speed tachometer as a reference measurement. The maximum and minimum percentage error found is 0.099% and 0.05% respectively. Results validated the effectiveness of the proposed technique and its potential applications in electric drives and automation.

PL

Zaproponowano tani system do pomiaru prędkoścoi katowej z wykorzystaniem czujnika optycznego. Jako czujnik wykorzystano typowy fotodetektor stosowany w myszkach komputerowych. Prograam oblicza ilość obrotów na minutę RPM. Na podstawie bada© eksperymentalnych określono dokładność pomiaru na 0.1%.

3

High speed imaging method for rotational speed calibration

Kędzierski Łukasz

Przegląd Elektrotechniczny

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2019

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R. 95, nr 5

184--187

EN

The paper introduces a method of rotational speed measurement calibration based on the image acquired by a high speed camera. Presented method proves to be superior to the commonly used strobe light method in both the accuracy and immunity to aliasing. Detailed calculations of the uncertainty of the method are going to be presented followed by the description and results of the experiment conducted in order to prove the high speed imaging calibration method accuracy. The method could be used for applications where very high precision of rotational speed measurement is critical. The development of the presented method has been performed in the Institute of Aviation in Warsaw in order to fulfill the very stringent requirements of the turbo-fan engines certification tests.

PL

Artykuł ten opisuje metodę kalibracji prędkości obrotowej bazującą na obrazie z kamery szybkoklatkowej. Zaprezentowana metoda udowadnia swoją wyższość nad powszechnie stosowaną metodą stroboskopową, zarówno pod względem dokładności, jak i odporności na zjawisko aliasingu. W artykule opisano dokładne wyliczenia niepewności pomiaru oraz pokazano wyniki testu przeprowadzonego w celu wykazania dokładności kalibracji prędkości obrotowej. Opisana metoda znajduje zastosowanie w systemach, w których precyzja pomiaru prędkości obrotowej jest krytyczna. Rozwój prezentowanej metody został przeprowadzony w Instytucie Lotnictwa na potrzeby testów certyfikacyjnych silników turbowentylatorowych.

4

Comparison of Selected Fair-optimization Methods for Flow Maximization between Given Pairs of Nodes in Telecommunications Network

Zalewski G., Ogryczak W.

Journal of Telecommunications and Information Technology

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2016

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nr 3

18--24

EN

Dimensioning of telecommunications networks requires the allocation of the ows (bandwidth) to given trac demands for the source-destination pairs of nodes. Unit ow allocated to the given demand is associated with revenue that may vary for dierent demands. Problem the decision-making basic algorithms to maximize the total revenue may lead to the solutions that are unacceptable, due to "starvation" or "locking" of some demand paths less attractive with respect to the total revenue. Therefore, the fair optimization approaches must be applied. In this paper, two fair optimization methods are analyzed: the method of ordered weighted average (OWA) and the reference point method (RPM). The study assumes that ows can be bifurcated thus realized in multiple path schemes. To implement optimization model the AMPL was used with general-purpose linear programming solvers. As an example of the data, the Polish backbone network was used.

5

A Family of MAV Drives lnvestigation

Dalewski R. T., Gumowski K., Barczak T., Godek J.

Przegląd Mechaniczny

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2015

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nr 10

39--42

EN

This material was gathered to observe the effect of surface finishing on rotors made by means of rapid prototyping techniques. Two rapid prototyping methods were used - Selective Laser Sintering (SLS) and Fused Deposition Modeling (FDM). Both were finished with the same procedure - a cyanoacrylic coating was applied and further manually finished with abrasive methods. Further microscopic investigation and roughness tests were performed to observe the quality of surface finishing. Rotor samples were finally tested to quantify aerodynamic performance (experimentally, CFD and PIV techniques were involved).

PL

Prezentowane wyniki badań służą zobrazowaniu wpływu obróbki wykańczającej powierzchnie wentylatorów wytworzonych metodami szybkiego prototypowania. Zastosowano dwa rodzaje metod szybkiego prototypowania - SLS (spiekanie wiązką lasera) i jedną z najbardziej rozpowszechnionych metod przetopu pręta tworzywowego (FDM). W obu przypadkach zastosowano analogiczną metodę wykończania surowych elementów przez nałożenie i ręczną obróbkę ścierną powłoki uzyskanej na bazie cyjanoakrylu. Przeprowadzono badania mikroskopowe oraz analizy chropowatości powierzchni w celu określenia właściwości uzyskanej warstwy wierzchniej. Próbki wirników zostały przebadane pod względem osiąganych wyników aerodynamicznych z zastosowaniem pomiarów wagowych i PIV w obszarze eksperymentalnym oraz z zastosowaniem modelowania metodami numerycznej mechaniki płynów.

6

Fem analysis of the modules bodies for building of the robots technological heads

Semjon J, Vagas M, Balaz V., Janos R

Applied Computer Science

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2014

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Vol. 10, no 3

34--45

EN

As a part the project it was necessary to design and implement accurate reducers and actuators in various kinematic solutions of modules. These modules will be possible to stack them into desired shapes, allowing them to be deployed in production machines and robotic equipment according to the specific customer requirements, e.g. technological heads. The article deals with designing and especially FEM analysis modules – technological heads for 2 and 3 axis handling and robotic systems. Designed modules – technological heads will allow correcting inaccura-cies motion manipulator or less precise robot. Solving of these modules is based on the use of smart actuators consisting of engine, precise gearbox and appropriate sensing technique. Control of the motion will be imple-mented on the basis of information obtained from sensors placed directly in drives the positioning module and the sensors working environment according to specific requirements for each application.

7

Kolorowa energia na TGE. Cz. II

Brodziński K.

Czysta Energia

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2009

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Nr 11

20-23