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Wyświetlanie 1-12 z 12
Tytuł:
Badanie mikrobiologiczne tuszek drobiu mrożonego
Mikrobiologicheskie issledovanija morozhennykh tush domashnikh ptic
Microbiological examination of the frozen poultry
Autorzy:
Maleszewski, J.
Borowiak, M.
Chwastek, M.
Dabrowa, B.
Frasunkiewicz, B.
Meinhardt, S.
Nowotko, S.
Swiatkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/874486.pdf
Data publikacji:
1966
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Źródło:
Roczniki Państwowego Zakładu Higieny; 1966, 17, 5
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of SMC Cores Produced at a Low Compacting Temperature
Autorzy:
Jakubas, A.
Gębara, P.
Seme, S.
Gnatowski, A.
Chwastek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1032892.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.60.-d
75.60.Ej
77.84.Lf
Opis:
Soft magnetic composites are readily used in the design of electromagnetic converters and electrical machines. In the paper, the magnetic properties of "home-made" cores made of iron powder and suspense polyvinyl chloride are examined. Samples were prepared by hot pressing of a PVC/Fe powder mixture with a different ratio of constituent components. Phase composition was investigated using an X-ray diffractometer and the presence of α-Fe was detected. Measurements of magnetic permeability revealed its allometric decrease with an increase of PVC content in composite. For the description of magnetization curves the phenomenological Jiles-Atherton model is used. The results of simulations are in a qualitative agreement with experiment.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1289-1293
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prezentacja autorskiego programu automatycznego pomiaru znaczków tłowych na obrazach zdjęć lotniczych
Software for automatic measurement of fiducial marks on digital air images
Autorzy:
Chwastek, T.
Mikrut, S.
Powiązania:
https://bibliotekanauki.pl/articles/131168.pdf
Data publikacji:
2006
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
automatyzacja
fotogrametria cyfrowa
zdjęcia lotnicze
znaczki tłowe
automatization
digital photogrammetry
air photography
fiducial markers
measurement
Opis:
Gwałtowny rozwój zainteresowania fotogrametrią w ostatnich latach spowodowany jest głównie faktem wprowadzenia technologii cyfrowej. Oprócz szybkiego dostępu do danych, istotnym czynnikiem jest możliwość automatyzacji niektórych procesów. Współczesne oprogramowanie komercyjnie pozwala znacznie skrócić czas opracowań fotogrametrycznych, a co za tym idzie podnieść ich wydajność. Prace nad zautomatyzowaniem etapów produkcji fotogrametrycznej realizowane są w wielu ośrodkach naukowo-badawczych na całym świecie. Również w Zakładzie Fotogrametrii i Informatyki Teledetekcyjnej Akademii Górniczo-Hutniczej w Krakowie prowadzone są badania w tym kierunku. Ponieważ automatyzacja pomiarów na obrazach cyfrowych podnosi jakość i wydajność opracowań fotogrametrycznych, podjęto próby ich rozwijania. Wyniki badań przedstawione poniżej, pozwalają optymistycznie patrzeć w rozwój własnych algorytmów i oprogramowania. Ma to duże znaczenie, ponieważ bazowanie na własnym oprogramowaniu pozwala na jego szybki i praktycznie nieograniczony rozwój. Pomiar znaczków tłowych na zdjęciach lotniczych jest pierwszym krokiem w kierunku automatyzacji dalszych etapów technologii fotogrametrycznej. Artykuł niniejszy prezentuje program, który powstał w ZFiIT AGH Kraków. W artykule opisano przykład zaimplementowania powstałych algorytmów automatycznego pomiaru znaczków tłowych na obrazie cyfrowym, przy znanych elementach orientacji wewnętrznej. Opisano autorski program „Interior Orientation”, pozwalający na automatyczą orientację wewnętrzną w oparciu o zdefiniowane wcześniej w bazie danych obrazy znaczków tłowych wybranych kamer fotogrametrycznych. Sprawdzono poprawność jego działania, określono jego przydatność do zastosowań fotogrametrycznych oraz dokonano porównania z profesjonalnym oprogramowaniem. Manualnego pomiaru dokonano przy pomocy oprogramowania Dephos, półautomatycznego w PCI Geomatica. Uzyskano porównywalną dokładność na poziomie 0.25 piksela (średni błąd pomiaru znaczka tłowego).
The rapid development of interest in photogrammetry in recent years has been caused mainly by the introduction of digital technology. In addition to rapid access to databases, another critical factor is the possibility of automatization of some of the processes. Contemporary software available on commercial market can cut the time of photogrammetric work to a minimum. Work on the automatization of photogrammetry production steps has been carried out in many research and development centres. In addition, the Department of Photogrammetry and Remote Sensing Information of the University of Science and Technology in Cracow (AGH) conducts research in this direction. This research was focused on the development of the automatization of measurements on digital images, because it could increase the quality and efficiency of photogrammetric work. The results shown below support the further development of own algorithms and software. It is of great importance, because relying on own software enables its quick and unlimited development. This paper presents software which has been developed at University of Science and Technology in the Department of Photogrammetry and Remote Sensing Information in Cracow (AGH). This paper presents an example of the implementation of developed algorithms, from the point of view of specific use, i.e. the automatic measurement of the fiducial mark on a digital image with known internal orientation parameters. The original "Interior Orientation" software has been described. It can execute automatic internal orientation, based on the fiducial mark images of selectedphotogrammetric cameras, previously defined in a database. Its accuracy was checked along with its use in photogrammetric applications and compared to a professional application. The manual measurement was carried out with the use of the Dephos software, while the semi-automatic measurement was carried out under the PCI Geomatica system. The results were on a comparable level of accuracy of 0.25 pixels.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2006, 16; 125-133
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active vibration reduction operator’s seat with the use of controlled single-acting pneumatic actuator
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/247371.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mobile heavy machines
unsprung vehicles
active reduction of vibration
controlled suspension seats
pneumatic actuator
Opis:
Mobile heavy machines produce vibrations with low natural frequencies. Because they tend to ride at low speeds, excitations due to road roughness excite low frequency vibrations, which can be reduced by active or semi active methods only. Under conditions of low frequency vibrations, energy dissipation in tires will reduce the vibration intensity in a minor degree only. In the unsprung mobile machine vibration isolation system are provided between a vibration source and the protected object (operator) along the path of vibration propagation. Most machines are now equipped with controlled suspension seats. In the case of active suspensions, the external energy source is required, for instance in the form of compressed air. The compressed air has the advantage that it is generally available in heavy machines as the working fluid and is environmentally friendly. Simulation tests were carried out both in the time domain in Matlab-Simulink and in the frequency domain in the program Mathcad. Simulation tests were performed to investigate effectiveness and stability of the proposed solution and the results were deemed satisfactory. The system was found to be feasible and implementable with respect to every parameter. The first purpose of this study is to develop a simulation model of the active suspension of operator's seat based on an adjustable pneumatic actuator. The other purpose of this study is to examine the effectiveness of different control strategies.
Źródło:
Journal of KONES; 2015, 22, 3; 13-19
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness of the active pneumatic suspension of the operator’s seat of the mobile machine in depend of the vibration reduction strategies
Autorzy:
Chwastek, S.
Pobędza, J.
Powiązania:
https://bibliotekanauki.pl/articles/245957.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
unsprung mobile machines
active vibration reduction
controlled suspension seats
pneumatic actuator
Opis:
Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.
Źródło:
Journal of KONES; 2018, 25, 3; 93-98
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness of the active pneumatic suspension of the operator’s seat of the mobile machine in depend of the vibration reduction strategies
Autorzy:
Chwastek, S.
Pobędza, J.
Powiązania:
https://bibliotekanauki.pl/articles/244967.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
unsprung mobile machines
active vibration reduction
controlled suspension seats
pneumatic actuator
Opis:
Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.
Źródło:
Journal of KONES; 2018, 25, 4; 43-48
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model identification of active pneumatic vibration reduction operator’s seat of mobile machines
Autorzy:
Chwastek, S.
Pobędza, J.
Powiązania:
https://bibliotekanauki.pl/articles/244627.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
unsprung machines
active reduction of vibration
controlled suspension seats
pneumatic actuator
Opis:
Low-frequency vibrations, generated in mobile machines during their driving, could be reduced only by use of active or semiactive methods. In conditions of low-frequency vibrations, energy dissipation in the machines tires slightly reduces the intensity of the vibration. Unsprung mobile machines are usually equipped with system of vibration isolation, which is located on the way of vibration propagation, between the vibration source and the protected object (the operator of the machine). Generally, controlled seat suspension is used. In the case of the active suspensions, it is necessary to provide external energy, e.g., in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator. Currently aim of the study was experimental verification of the theoretical results; this verification was performed on the laboratory test bench. In the stand tests, special attention was paid on the assumed models of friction and thermodynamic phenomena in pneumatic actuator, as well as on the control system. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using Matlab-Simulink Real-Time software. Identification of the simulation model allows for getting the right parameters of the seat suspension. In addition, parametric optimization of the seat suspension system and functional optimization of control strategy would be possible in the next step.
Źródło:
Journal of KONES; 2016, 23, 4; 55-62
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modulation effect of vibration frequency of an unsprung heavy machine under the variable road adhesion conditions
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/244951.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mobile heavy machines
unsprung vehicles
galloping effect
adhesion factor
slipping action
frequency modulation of vibration
Opis:
Mobile heavy machines as unsprung vehicles exhibit low dissipation ability, hence the ride even at low speeds may give rise to intensive vibration. Particularly dangerous situations occur when the road wheels break away from the road surface due to the ’galloping’ effect, being the result of excited vertical and angular vibration of the machine frame in the vertical plane of symmetry. That implies a major restriction on the ride velocity, which negatively impacts on the machine performance. Vibrations thus produced are mostly in the low-frequency range and hence energy dissipation in tyres will reduce the vibration intensity in a minor degree only. The motion of tired wheels will always involve some slipping. While investigating the feasibility of increasing the efficiency of the vibration reduction systems, one ought to take into account the variable adhesion of road wheels due to different dynamic loading acting on the vehicle axles during the ride. Observations of unsprung machines during the ride suggest the occurrence of self-excited vibration. Mobile machines constitute dynamic systems, which can be governed by nonlinear, sometimes non-stationary differential equations of motion. Their stability also depends on intensity of external vibrations. This study investigates the motion of unsprung mobile machines, taking into account the dynamic processes in the driving system under the conditions of the variable adhesion of road wheels. The model of interaction between a tired wheel and the terrain takes into account the relationship between the road wheel adhesion factor and the slipping action. Mathcad supported by Matlab-Simulink and in the frequency domain – simulations in the time domain. The purpose of the simulation procedure was to find the causes of the vibration modulation frequency and determine the conditions triggering the occurrence of self-excited vibrations. Simulations are supported by the analysis of motion stability.
Źródło:
Journal of KONES; 2013, 20, 4; 55-62
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal stabilisation of platforms suspended by ropes using the frequency converter control method
Stabilizacja optymalna liniowych platform podwieszanych metodą sterowania przemiennikami częstotliwości
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/374307.pdf
Data publikacji:
2011
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
platforma
stabilizacja
napęd i sterowanie
platform
stabilization
drive and control
Opis:
The ability to relocate the load from point A to B in the working space and within the specified time cannot be treated as an exhaustive definition of functional quality of modern cranes. Further requirements include the minimization of dynamic loading during the start-up and backing phase and vibration reduction through the control of drives. Besides, when 3D loads are to be handled, their position has to be stabilized. The objective function in this case becomes the minimal time of operation. This study provides a synthesis of an automatic control system for positioning and stabilization of the platform whilst in service.
Zdolność do przemieszczenia ładunku z punktu A do punktu B przestrzeni roboczej w określonym czasie nie wyczerpuje pojęcia funkcjonalności współczesnej maszyny dźwigowej. Przeciwnie, wymaga się, aby poprzez sterowanie napędami minimalizować obciążenia dynamiczne w fazach rozruchu i hamowania jak również drgania przenoszonego ładunku. W przypadku przenoszenia ładunków przestrzennych dochodzi warunek stabilizacji położenia nosiwa. Jednocześnie funkcją celu jest minimum czasu operacji. W pracy przedstawiono syntezę układu automatycznej regulacji zapewniającego precyzyjne pozycjonowanie oraz stabilizację położenia poziomego platformy w czasie pracy.
Źródło:
Transport Problems; 2011, 6, 4; 61-68
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semiactive vibration reduction of operator’s seat with the use of controlled magnetorheological damper
Autorzy:
Chwastek, S.
Kozioł, P.
Powiązania:
https://bibliotekanauki.pl/articles/241873.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
seats suspensions
mobile machines
magnetorheological damper
semi-active methods
controlled suspension
reduction of vibration
Opis:
Low speeds of mobile heavy machines makes that the force derived from rough roads cause intense excitation of low frequency vibration, the reduction of which is possible only by active or semi active methods. In conditions of low frequency, the energy dissipation in the tire reduces the vibration intensity in a minor degree only magnetorheological dampers are free from this defect, which they properties changing under influence an electric field functioning on ferromagnetic particles of oil suspension. A controlling coil current, which is mounted in the damper piston, could control density of magnetic field lines (magnetic field intensity) directly in viscous hole of piston, and hence viscous drag force. Electric energy needed to control magnetorheological damper is generally available in each of mobile heavy machines. Simulation tests were performed to investigate effectiveness and stability of the proposed solution and the results were deemed satisfactory. The system was found to be feasible and implementable with respect to every parameter. The purpose of this study was to develop a simulation model of the semi active suspensions of operator’s seat based on magnetorheological damper, and to examine the effectiveness of using different control strategies.
Źródło:
Journal of KONES; 2015, 22, 4; 59-66
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial model of the unsprung wheeled machine’s dynamic system
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/241952.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
spatial model
dynamic system
mobile heavy machines
unsprung vehicles
"galloping" effect
"snake meandering” effect
adhesion factor
slipping action
vibration
differential gear
Opis:
Mobile heavy machines as unsprung vehicles exhibit low dissipation ability, hence the ride even at low speeds may give rise to intensive vertical and angular vibration. Vibrations thus produced are mostly in the low-frequency range and hence energy dissipation in tires will reduce the vibration intensity in a minor degree only. Particularly dangerous situations occur when the road wheels break away from the road surface due to the ’galloping’ effect. Kinematic excitation acting on the wheels is mostly uncorrelated stochastic (random) processes, giving rise to the "snake meandering" effect. That implies a major restriction on the ride velocity, which negatively affects the machine performance. The motion of tired wheels will always involve certain slipping. While investigating the feasibility of increasing the efficiency of the vibration reduction systems, one ought to take into account the variable adhesion of road wheels due to different dynamic loading acting on the vehicle axles during the ride. This study investigates the motion of unsprung mobile machines, taking into account the dynamic processes in the driving system under the conditions of the variable adhesion of road wheels. The model of interaction between a tired wheel and the terrain takes into account the relationship between the road wheel adhesion factor and the slipping action, as well as the impacts of the differential gear on distribution of drive torque. The 3D (spatial) model of a backhoe loader is considered. It is a two-axle self-propelled machine on a wheeled chassis. The mathematical model constitutes nonlinear and non-stationary differential equations of motion. Their stability is therefore associated with vibration intensity. Simulations in the time domain were supported by Matlab-Simulink. The purpose of this study is to improve the safety features during the ride of mobile heavy machines, basing on the parametric optimization of the model.
Źródło:
Journal of KONES; 2014, 21, 2; 45-52
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The frequency converter control method in positioning and stabilisation of a platform suspended on ropes in conditions of a time - variant centre of gravity
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/247923.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
automatic control system
simulation
asynchronous induction motor
hoisting winch
Opis:
When handling materials in space it is required that the materials to be hoisted should be stabilised and their position precisely controlled. Attempts are made to minimise the dynamic loading during the start-up and braking phase and to reduce vibration of the material being handled, at the same time ensuring the minimal time of operation. When the admissible value of positioning and levelling errors are very small, some effective methods of drive control are required. This study investigates an asymmetrically loaded platform suspended on ropes and people moving with respect to it during the hoisting phase. The positioning and levelling errors are minimised by controlling voltage fluctuations of the current supplying asynchronous induction motors. The proposed solution uses an optimal LQR controller. Both free and forced vibrations of the platform are low-frequency vibrations, so the scalar method of controlling the output voltages are recommendable, where feedback loops in the electro-magnetic part of the system are neglected. The losses and time delays associated with modulation of the velocity characteristics of the induction motor being omitted, the optimal control strategy of frequency control is developed to effectively handle the control plant. This study has demonstrate
Źródło:
Journal of KONES; 2012, 19, 2; 87-94
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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