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Wyszukujesz frazę "active detection" wg kryterium: Temat


Tytuł:
Test Signal Design for Failure Detection: a Linear Programming Approach
Autorzy:
Scola, H. R.
Nikoukhah, R.
Delebecque, F.
Powiązania:
https://bibliotekanauki.pl/articles/908093.pdf
Data publikacji:
2003
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
automatyka
failure detection
large scale programming
failure isolation
bounded perturbations
active detection
Opis:
A new methodology for the design of filters that permits failure detection and isolation of dynamic systems is presented. Assuming that the normal and the faulty behavior of a process can be modeled by two linear systems subject to inequality bounded perturbations, a method for the on-line implementation of a test signal, guaranteeing failure detection, is proposed. To improve the fault detectability of the dynamic process, appropriate test signals are injected into the system. All the computations required by the proposed method are implemented as the solution of large sparse linear optimization problems. A simple numerical example is given to illustrate the proposed procedure.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2003, 13, 4; 515-526
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Emergence Angle on Acoustic Transmission in a Shallow Sea
Autorzy:
Lu, Yanyang
Yang, Kunde
Liu, Hong
Huang, Chunlong
Powiązania:
https://bibliotekanauki.pl/articles/177665.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
underwater acoustic
emergence angle
transmission loss
active sonar detection
Opis:
In this study, the effect of the emergence angle of a source array on acoustic transmission in a typical shallow sea is simulated and analyzed. The formula we derived for the received signal based on the Normal Mode indicates that the signal is determined by the beamform on the modes of all sources and the samplings of all modes at the receiving depth. Two characteristics of the optimal emergence angle (OEA) are obtained and explained utilizing the aforementioned derived formula. The observed distributions of transmission loss (TL) for different sources and receivers are consistent with the obtained characteristics. The results of this study are valuable for the development and design of active sonar detection.
Źródło:
Archives of Acoustics; 2020, 45, 1; 3-9
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On infinite horizon active fault diagnosis for a class of non-linear non-Gaussian systems
Autorzy:
Punčochář, I.
Šimandl, M.
Powiązania:
https://bibliotekanauki.pl/articles/330710.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
active fault detection
nonlinear stochastic system
optimal input design
dynamic programming
detekcja błędu
układ stochastyczny
układ nieliniowy
optymalizacja pobudzenia
programowanie dynamiczne
Opis:
The paper considers the problem of active fault diagnosis for discrete-time stochastic systems over an infinite time horizon. It is assumed that the switching between a fault-free and finitely many faulty conditions can be modelled by a finite-state Markov chain and the continuous dynamics of the observed system can be described for the fault-free and each faulty condition by non-linear non-Gaussian models with a fully observed continuous state. The design of an optimal active fault detector that generates decisions and inputs improving the quality of detection is formulated as a dynamic optimization problem. As the optimal solution obtained by dynamic programming requires solving the Bellman functional equation, approximate techniques are employed to obtain a suboptimal active fault detector.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 4; 795-807
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of thinning of homogeneous material using active thermography and classification trees
Autorzy:
Dudzik, Sebastian
Dudek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/1848987.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active thermography
classification tree
defect detection and characterization
material thinning detection
Opis:
Active thermography is an efficient tool for defect detection and characterization as it does not change the properties of tested materials. The detection and characterization process involves heating a sample and then analysing the thermal response. In this paper, a long heating pulse was used on samples with a low thermal diffusivity and artificially created holes of various depths. As a result of the experiments, heating and cooling curves were obtained. These curves, which describe local characteristics of the material, are recognized using a classification tree and divided into categories depending on the material thickness (hole depths). Two advantages of the proposed use of classification trees are: an in-built mechanism for feature selection and a strong reduction in the dimensions of the pattern. Based on the experimental study, it can be concluded that classification trees are a useful tool for the thinning detection of homogeneous material.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 89-105
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Możliwości wykorzystania termografii aktywnej do lokalizacji zbrojenia w elementach żelbetowych
Possibilities of using active ir thermography for localization of steel bars in reinforced concrete
Autorzy:
Noszczyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/134750.pdf
Data publikacji:
2016
Wydawca:
ADVSEO
Tematy:
active thermography
non-destructive testing
material inclusions
detection of rebar
Opis:
The paper presents the possibility of using non-destructive testing with active thermography to the location of reinforcement in concrete elements. Four reinforced concrete elements in the form of beams with dimensions of 24 x 24 x 200 cm was researched. The beams had the main reinforcement with diameters sequentially: 12 mm, 16 mm, 20 mm and 25 mm. Stirrups with a diameter of 6 mm were placed every 20 cm. Lagging for the main reinforcement of test surface was 26 mm. Reinforced concrete elements were heated with an infrared lamp and thermal images were recorded periodically at intervals of 1 min. Preliminary studies have shown that detection of reinforcement in concrete elements using active thermography is possible. The rebar was visible on the thermograms from the start of the cool down phase for about 20 min after. The study contains a description of the test stand, and the tests performed. The paper also highlighted the problems encountered on the implementation of research and prospect of development active thermography as a non-destructive testing.
Źródło:
Technical Issues; 2016, 2; 39-44
2392-3954
Pojawia się w:
Technical Issues
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of contamination of coal processing plants and environmental waters using bubble velocity measurements – advantages and limitations
Autorzy:
Zawala, J.
Malysa, E.
Krzan, M.
Malysa, K.
Powiązania:
https://bibliotekanauki.pl/articles/110915.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bubble velocity
water purity
surface active contaminants
method detection
adsorption layer
Opis:
The paper presents fundamentals of a simple physicochemical method (SPMD) and analysis of results obtained when the method was applied for detection of organic contaminations (surface-active substances SAS) in samples of environmental and industrial waters. The method is based on measurements of variations of air bubble local velocities, which can be significantly changed in presence of surface-active contaminants. Lowering of the bubble velocity is a consequence of a motion induced dynamic adsorption layer (DAL) formed over surface of the rising bubble. The DAL formation retards the surface fluidity and the bubble rising velocity can be lowered by over 50% when the bubble surface is completely immobilized. We showed that the SPMD is a very sensitive tool (detection limit even below 1 ppm) for detection of various kinds of surface-active substances (ionic, non-ionic) in water samples. On the basis of results obtained using precise laboratory set-up, an accuracy of the SPMD is discussed. Moreover, effect of inert electrolyte addition on the bubble velocity lowering and value of detection limit of the SPMD is discussed. Simple approach, enabling quantitative analysis of the surface-active contaminants in samples collected, based on “equivalent concentrations” determination, is proposed. Results obtained for industrial (Jankowice and Knurow coal processing plants, Jaslo Refinery channel) and environmental waters (Wisloka and Ropa river) are used for detailed analysis and critical discussion of advantages and limitations of the SPMD.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 143-157
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of material defects in reinforced concrete slab using active thermography
Autorzy:
Różański, L.
Ziopaja, K.
Powiązania:
https://bibliotekanauki.pl/articles/114442.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
active IR (pulsed or step heating) thermography
damage detection
non-destructive testing
Opis:
In order to validate the practical usage of passive and active infrared thermography for bridge inspection, a number of experimental studies have been conducted. Concrete slab of dimension of 60×60×10 cm made of concrete of strength class C35/45 was the object of research. Steel bars type B500SP with a diameter of ø10 and ø12 mm were used as reinforcement of analyzed slab. Four structure discontinuities imitating damages were implemented inside the slab. Using various methods of thermal excitation, the sensitivity of the slab response using infrared cameras was investigated. The paper presents the results of experiment and FEM simulation.
Źródło:
Measurement Automation Monitoring; 2017, 63, 3; 82-85
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie wybranych metod wyznaczania obszaru płomienia w wizyjnym systemie diagnostycznym
Comparision of selected flame area detection methods in vision disgnostic system
Autorzy:
Sawicki, D.
Kotyra, A.
Powiązania:
https://bibliotekanauki.pl/articles/408672.pdf
Data publikacji:
2013
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
wykrywanie brzegu obszaru
płomień
spalanie
kontur aktywny
edge detection
flame
combustion
active contour
Opis:
W pracy przedstawiono porównanie wybranych metod wykrywania krawędzi dla obrazów spalania pyłu węglowego. Porównano metodę gradientową Canny’ego z metodą zbiorów poziomicowych oraz metodą opartą o model konturu aktywnego Chan-Vese. Wyniki badań pokazują, że metoda korzystająca z modelu Chan-Vese dobrze odwzorowała brzeg obszaru.
This paper presents comparison edge detection method of combustion pulverized coal. Compared method are: Canny edge detection operator, level set method and Chan-Vese active contour method. Experimental results show that edges extracted with method based on Chan-Vese active contour model gives good result.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2013, 4; 14-17
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on islanding detection of solar distributed generation based on best wavelet packet and neural network
Autorzy:
Xi, Zhongmei
Zhao, Faqi
Zhao, Xiangyang
Peng, Hong
Xi, Chuanxin
Powiązania:
https://bibliotekanauki.pl/articles/141157.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active distribution network
islanding detection
neural network
solar distributed generation
wavelet pocket transform
Opis:
The active distribution network (ADN) represents the future development of distribution networks, whether the islanding phenomenon occurs or not determines the control strategy adopted by the ADN. The best wavelet packet has a better time-frequency characteristic than traditional wavelet analysis in the different signal processing, because it can extract better and more information from the signal effectively. Based on wavelet packet energy and the neural network, the islanding phenomenon of the ADN can be detected. Firstly, the wavelet packet is used to decompose current and voltage signals of the public coupling point between the distributed photovoltaic (PV) system and power grid, and calculate the energy value of each decomposed frequency band. Secondly, the network is trained using the constructed energy characteristic matrix as a neural network learning sample. At last, in order to achieve the function of identification for islanding detection, lots of samples are trained in the neural network. Based on the actual circumstance of PV operation in the ADN, the MATLAB/SIMULINK simulation model of the ADN is established. After the simulation, there are good output results, which show that the method has the characteristics of high identification accuracy and strong generalization ability.
Źródło:
Archives of Electrical Engineering; 2019, 68, 4; 703-717
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykrywanie defektów z wykorzystaniem termografii aktywnej i algorytmu k-średnich
Detection of Defects Using Active Thermography and k-Means Algorithm
Autorzy:
Dudzik, Sebastian
Powiązania:
https://bibliotekanauki.pl/articles/275938.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
algorytm k-średnich
wykrywanie defektów
termografia aktywna
k-means algorithm
defect detection
active thermography
Opis:
W pracy przedstawiono nową metodę wykrywania defektów materiałowych z wykorzystaniem termografii aktywnej. W celu zwiększenia kontrastu cieplnego dokonano przetwarzania wstępnego zarejestrowanej sekwencji termogramów metodami morfologii matematycznej. Do wykrywania defektów zastosowano algorytm k-średnich. W pracy zbadano wpływ miary odległości używanej w opisywanym algorytmie oraz doboru danych wejściowych na efektywność opisywanej metody. Eksperyment przeprowadzono dla próbki wykonanej z kompozytu zbrojonego włóknem węglowym (CFRP). W badaniach stwierdzono, że najmniejsze błędy wykrywania defektów za pomocą opisywanej metody uzyskuje się dla kwadratowej odległości euklidesowej.
The paper presents a new method of detecting material defects using active thermography. In order to increase the thermal contrast, preprocessing of the recorded sequence of thermograms was carried out using mathematical morphology methods. The k-means algorithm was used to detect defects. The work examined the impact of distance measure used in the described algorithm and the selection of input data on the effectiveness of the described method. The experiment was carried out for a sample made of carbon fiber reinforced composite (CFRP). Studies have shown that the smallest errors in defect detection using the described method are obtained for the square Euclidean distance.
Źródło:
Pomiary Automatyka Robotyka; 2019, 23, 3; 11-15
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł

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