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Wyświetlanie 1-15 z 15
Tytuł:
Application of the HDR imaging in vehicles’ video tracking systems
Autorzy:
Mazurek, P.
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/393309.pdf
Data publikacji:
2010
Wydawca:
Polskie Stowarzyszenie Telematyki Transportu
Tematy:
lokalizacja pojazdów
inteligentne systemy transportowe
ITS
High Dynamic Range Images
HDRI
vehicles tracking
intelligent transport system (ITS)
high dynamic range images
Opis:
Video systems are used in Intelligent Transportation Systems for vehicles’ tracking. Cameras typically used in these systems are characterized by relatively low dynamic range which is only a fragment of the dynamic range of the human eye. In order to adapt to the lighting conditions the cameras feature dynamic changes of the gain and exposure. For vehicles there is a very wide range of the observed brightness of details because of the variety of vehicles’ colors and the presence of elements reflecting light in different ways, as well as changing lighting conditions. This means that even if the camera is able to capture the relevant dynamic range, there is a restriction of the distinguishability of details, which is essential in the process of detecting the location of vehicles. The use of HDR imaging techniques based on various exposures helps to increase the dynamic range and improves the accuracy of vehicles’ positions estimation.
Źródło:
Archives of Transport System Telematics; 2010, 3, 4; 32-36
1899-8208
Pojawia się w:
Archives of Transport System Telematics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Effect of Air to Fuel ratio Parameter on the Organophosphorus – Pesticide Analysis by GC-FPD
Autorzy:
Kilany, A. Y.
Elsayed, M. A.
Abd Elmegid, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/412130.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sensitivity
minimum detectability
dynamic range
linear range
organophosphorus pesticides
malathion
dimethoate
GC/FPD
Opis:
In the present contribution, sensitive and precise method for the quantification of Organophosphorus / Pesticides (Malathion and Dimethoate) in nanograms range has been developed. The performance of flame photometric detector (FPD), a selective detector (P&S-mode) that can be used in the analysis of organophosphorus compound, is evaluated in terms of sensitivity, selectivity and reproducibility. The performance of flame photometric detector was strongly depending on the absolute and relative flow rate of air and hydrogen gases. The optimum air-to-fuel ratio for detection of Malathion and Dimethoate was 0.4 and 0.3 (FPD-P mode). At this ratio, low picogram amounts of phosphor can be detected accurately (0.18 pgP) with a wide linear dynamic range of 0.18 pgP to 298 ngP. While, the optimum air-to-fuel ratio, for detection of Malathion and Dimethoate was 0.6 (FPD-S mode). In addition to, the method is precise with 4.5 % relative standard deviation (RSD). In conclusion, it could be proposed that this procedure can be recommended as a suitable method for the quantification of Malathion and Dimethoate in cases of acute poisoning.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 17, 3; 236-248
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SIGN detection and signed integer comparison for three-moduli SET {2n ±1, 2n+k}
Autorzy:
Torabi, Zeinab
Timarchi, Somayeh
Powiązania:
https://bibliotekanauki.pl/articles/2097970.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
computer arithmetic
residue number system
signed integer comparison
dynamic range partitioning
Opis:
Comparison, division, and sign detection are considered to be complicated op erations in a residue number system (RNS). A straightforward solution is to convert RNS numbers into binary formats and then perform complicated op erations using conventional binary operators. If efficient circuits are provided for comparison, division, and sign detection, the application of RNS can be extended to those cases that include these operations. For RNS comparison in three-moduli set τ = {2 n−1, 2 n+k , 2 n+1},(0 ≤ k ≤ n), we have found only one hardware realization. In this paper, an efficient RNS comparator is proposed for moduli set τ , which employs a sign-detection method and operates more efficiently than its counterparts. The proposed sign detector and comparator utilize dynamic range partitioning (DRP), which has been recently presented for unsigned RNS comparison. The delay and cost of the proposed comparator are lower than the previous works, which makes it appropriate for RNS applications with limited delay and cost.
Źródło:
Computer Science; 2021, 22 (3); 387-401
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frequency Dependent Mismatch Correction Scheme for Zero-IF Receivers
Autorzy:
Hibner, R.
Zieliński, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/226210.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
zero-IF
ZIF
compensation
quadrature
IQ
wideband
dynamic range
image correction
Opis:
This paper shows effective method of linear distortions compensation in zero-IF receivers. With application of frequency domain processing a computation efficient method was developed that allows to correct quadrature mismatch in Zero-IF receiver along with gain and group delay independent of receiving signal type. Method was implemented and tested on hardware platform confirming its effectiveness. This method makes it possible to build high sensitivity devices to monitor spectrum in very wide frequency ranges.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 1; 13-18
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High dynamic range imaging by perceptual logarithmic exposure merging
Autorzy:
Florea, C.
Vertan, C.
Florea, L.
Powiązania:
https://bibliotekanauki.pl/articles/330053.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
logarithmic image processing
human visual system
high dynamic range
logarytmiczne przetwarzanie obrazu
system wizualny człowieka
Opis:
In this paper we emphasize a similarity between the logarithmic type image processing (LTIP) model and the Naka–Rushton model of the human visual system (HVS). LTIP is a derivation of logarithmic image processing (LIP), which further replaces the logarithmic function with a ratio of polynomial functions. Based on this similarity, we show that it is possible to present a unifying framework for the high dynamic range (HDR) imaging problem, namely, that performing exposure merging under the LTIP model is equivalent to standard irradiance map fusion. The resulting HDR algorithm is shown to provide high quality in both subjective and objective evaluations.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 4; 943-954
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
No-reference quality metric for high dynamic range imaging system based on curvature analysis in tensor domain
Autorzy:
Jiang, Gangyi
Yu, Jiaowen
Yu, Mei
Song, Yang
Peng, Zongju
Chen, Fen
Powiązania:
https://bibliotekanauki.pl/articles/173642.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high dynamic range image
no-reference quality metric
tensor domain
curvature analysis
quality-related label feature matrix
Opis:
High dynamic range imaging systems can offer a more complete representation of scene, aiming to capture all brightness information of a visible range of scene, even in extreme lighting conditions.This paper proposes a no-reference quality metric for high dynamic range image (HDRI), in which a combination of tensor decomposition and curvature analysis is used to construct an efficient featureset that is sensitive to degradation levels of patches in HDRIs. Tensor decomposition maintains the majority of color information of an HDRI, and the geometric structure information of the HDRI is then extracted by a curvature analysis. A quality-related label feature matrix is subsequently defined and obtained by using a feature set and a sparse dictionary with quality-related labels. Then, the multi-dimensional local feature set of the HDRI is determined from the quality-related label feature matrix. Finally, the local feature set and other global feature set are pooled to predict the quality of the HDRI. The prediction performance of the proposed metric is verified by three public test databases, and the experimental results indicate that both its Pearson linear correlation coefficientand Spearman rank-order correlation coefficient are better than those of other no-reference metrics.The proposed metric produces statistically better assessment results, implying a higher consistency with human visual perception.
Źródło:
Optica Applicata; 2019, 49, 4; 527-543
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie wybranych technik przetwarzania obrazów cyfrowych dla potrzeb określania zewnętrznych warunków oświetleniowych
Comparison of selected techniques of digital images conversion for determination of external daylighting conditions
Autorzy:
Górko, M.
Heim, D.
Szczepańska, E.
Powiązania:
https://bibliotekanauki.pl/articles/362567.pdf
Data publikacji:
2009
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
oświetlenie
nieboskłon
izohelia
HDR
fotografia o szerokim zakresie dynamiki
symulacje komputerowe
lighting
sky
isohel
High Dynamic Range
computer simulation
Opis:
W pracy omówiono dwie techniki opracowania obrazów cyfrowych dla numerycznych analiz oświetlenia dziennego. Porównano technikę o szerokim zakresie tonalnym HDR (bezpośrednia) z techniką pojedynczych obrazów przekształcanych na izohelie (pośrednia) w skali szarości, o znanej jasności odniesienia. Zastosowanie obu metod przedstawiono na przykładzie obrazów nieboskłonów uzyskanych dla wybranych dni marca i kwietnia 2009 roku nad miastem Łodzią. Na podstawie obrazów opracowano mapy luminancji półsfery niebieskiej i porównano je pod względem jakościowym otrzymanych wyników. Stwierdzono, że w przypadku techniki izoheli możliwe jest łatwe regulowanie zakresem tonalnym oraz uzyskanie dowolnego stopniowania bez względu na wielkość natężenia oświetlenia. Ponadto nie wymaga ona stosowania stosunkowo drogich zestawów do bezpośredniego pomiaru luminancji. Natomiast technika oparta na obrazach HDR jest znacznie bardziej uniwersalna pod warunkiem posiadania pełnego zestawu pomiarowego.
Two outdoor methods of daylight availability determination are described in a paper. The results obtained using HDR (High Dynamic Range) and Isohel methods for clear sky condition are presented and compared. Both method can be used for future work concerns investigations of daylight availability in Poland.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2009, T. 4; 37-44
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ANSDM converters dynamic range design process
Autorzy:
Golański, Ryszard
Godek, Juliusz
Powiązania:
https://bibliotekanauki.pl/articles/1402376.pdf
Data publikacji:
2020
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
delta modulation
non-uniform sampling
SNR
dynamic range
Lambert W function
sampling interval
Maple
modulacja delta
nierównomierne próbkowanie
zakres dynamiczny
funkcja Lamberta
odstęp próbkowania
Opis:
The results of analytic and simulating works proved that for nonstationary sources, the delta converters with adaptive sampling expose higher coding efficiency than the former proposals, based on uniform sampling methods. The knowledge of the sampling interval range and the algorithm of the Nonuniform Sampling Delta Modulation and Adaptive Nonuniform Sampling Delta Modulation allows finding the necessary number of the sampling intervals and their values that maximizes SNR. The total dynamic range of the ANSDM modulator is the product of the dynamic range both from sampling interval and step size adaptation. Due to the high complexity of the calculations, the ANSDMsoft program was developed to support computing. All computational works were carried out using the Maple environment. Maple allows to solve complex mathematical functions and display their results in a simple way. Most importantly, it supports the LambertW function, used in the computing of NSDM or ANSDM modulators parameters. Graphic illustrations of the NSDM and ANSDM modulator dynamic range as a function of the minimum and maximum sampling frequency are presented.
Źródło:
Science, Technology and Innovation; 2020, 10, 3; 1-7
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie techniki HDR do obrazów pozyskiwanych z sektorowego sonaru skanującego
Application of HDR image method for sector scanning sonar images
Autorzy:
Duda, J.
Powiązania:
https://bibliotekanauki.pl/articles/209905.pdf
Data publikacji:
2011
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
przetwarzanie obrazów
obraz sonarowy
sonar skanujący
histogram
wzmocnienie sygnału
rozróżnialność obiektów
HDR
image processing
sonar image
sector scanning sonar
object visibility
High Dynamic Range Image (HDRI)
Opis:
Obrazy pozyskiwane za pomocą sonarów sektorowych mają często ograniczoną głębokość bitową do ośmiu bitów. Powoduje to szereg restrykcji związanych z percepcją obrazów sonarowych, jak również z późniejszym ich przetwarzaniem. W artykule przedstawione zostały badania związane z zastosowaniem techniki uzyskiwania obrazów o szerokim zakresie tonalnym (High Dynamic Range) do obrazów sonarowych. Zastosowanie techniki HDR pozwala na zwiększenie ilości informacji przenoszonej przez obraz sonarowy i brak konieczności wyboru między lepszą reprezentacją dna czy też obiektów się na nim znajdujących.
The images obtained with sector scanning sonar have often bit depth limited to eight bits. It causes a lot of limitations related with sonar images perception and also later with their transformation. Already during sonar images registration process, the operator must decide what is more important to him. The operator must choose between good visibility of bottom or objects located on it. Such is a characteristic property of low dynamic range (LDR) images. In other words, operator has to choose between better representation of bottom or the objects, what is realized by changing the gain of the acoustic signal. Selection between better representation of the bottom or the objects is performed by increasing or reducing the strengthening of the acoustic wave generated by the sonar transducer. Increase in the strength of the acoustic wave causes additional distortion on the sonar image which can be observed particularly near the sonar transducer. These distortions are also produced by the presence of the object, growing if the object is nearby the sonar transducer. If the sonar acoustic wave is too strong, then induced distortions cause poor visibility of sonar images. Using the transformations of the low dynamic range sonar images to improve the poor visibility of particular elements often causes an additional loss of information. As a result, the image can become unreadable. Unfortunately, there is no possibility of artificial enhancement of the information contained in the image. The article presents the research related to HDR images using for the sonar images. The HDR method is used in photography to improve their perception. Using images with different value of exposition can be presented by both dark and bright elements. HDR images characterize a good object resolution. Nowadays, HDR images were used mainly in photography. In the article, the HDR method was applied for the first time to the sector scanning sonar images. In the sonar HDR images, the exposure value was replaced by the strength of the sonar acoustic signal. Using the HDR method in photography increases the aperture or decreases photo array sensitivity effect on the value of exposition. Inversely, to reduce exposure we must decrease the aperture or increase sensitivity of the matrix. For the sonar images there is only one parameter influencing the exposure value, namely the gain of the sonar acoustic signal. For the HDR sonar images, increasing exposure is equivalent to reduction of the gain acoustic signal and decreasing exposure with an enlargement of the gain acoustic signal. Using three images of different exposure during a single sonar registration, we obtain the high dynamic range sonar image. In contrary to the side scan sonar, which has to be towed several times over the same area, it allows to locate the sector scanning sonar on a tripod at the bottom. For this reason, the sector scanning sonar location does not occurr the distortion associated with the movement of the vessel and waving. Because the registered sonar images are not shifted mutually, there is not necessity to match them what simplify HDR sonar images process realization. The HDR technique can also be applied to images obtained from side-scan sonar. However, the main problem to have HDR images is obtaining images from the same place and their matching. Using the HDR method allows to enlarge the quantity of information contained in sonar image by increasing the bit width of the sonar image, namely from eight to sixteen bit. Obtaining more values and regular values distribution on the HDR sonar image histogram results in no necessity of choice between better representation of bottom or object located on the sonar image.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2011, 60, 3; 291-306
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The evaluation of the current state of EHF-sensors quality in the technical systems and its improvement
Autorzy:
Chovnyuk, Y. V.
Ivanov, E. A.
Dovhaljuk, V. B.
Shyshyna, M. A.
Gumenjuk, Y. O.
Sivak, I. N.
Powiązania:
https://bibliotekanauki.pl/articles/114875.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
aperture
coaxial line
dynamic range of the evaluation
extremely high frequency sensors
function of the entropy evaluation
scale of the entropy evaluation
oceny entropii
czujnik
funkcja oceny entropii
Opis:
In the article the function and the scale for the entropy evaluation of the current state of extremely high frequency (EHF-) sensors quality in the various technical systems which fits the requirements of universality and maximal independency from the human factor are offered. One may see such EHF-sensors for the analysis of the quick transformations of the biological liquids properties. It’s high lighted that the available methods of the determination of technical systems’ quality have essential flaws which consist in both subjectivism because the dominant role in the evaluation belongs to experts and legitimacy of providing them properties of universality which was proved by nobody. The scheme of EHF-sensor is analyzed for which one may create an analytical model. The problem of the fields’ determination at the working region of such sensor is discussed. The presented scheme is possible to use for the mathematical model and just for that part of the problem which is devoted to the transformation of the properties of the object. The results of calculation of components of electromagnetic field at the working space of EHF-sensor are discussed. One may estimate the sizes of this space. The offered function of the quality evaluation, the parameter of which is the quantity of own information of the explored sensor, provides the declared universality approach according to the principles of the information theory. The conformity to all requirements for the functions of the evaluation of the quality: continuity, monotonic and smoothness over the whole range of definition regardless of the probability distribution function, which is measured by the random value EHF-sensor was proved. The proposed scale of the entropy evaluation of the quality fits to standard settings of the diagnostic of the technical systems and has three sub ranges which determine the state of the EHF-sensors: good state, up state, and down state. Unlike the existing psychophysical scales the offered scale has dynamic range of the evaluation so the limits of the sub ranges will automatically change depending on the regulatory and technical requirements for the state of the explored EHF-sensor. Such approach provides adaptation of the scale to specific requirements which gives a chance to evaluate the qualitative state of the object more reliably. The results of modeling of the qualitative state of the sensor are given. The possible practical application of the offered function and scale is usage in the systems of monitoring and diagnostic for determination of the current qualitative state of the explored technical system, as well.
Źródło:
Zeszyty Naukowe. Quality. Production. Improvement; 2019, 2 (11); 26-40
2544-2813
Pojawia się w:
Zeszyty Naukowe. Quality. Production. Improvement
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza zakresu dynamicznego sygnału zawartego w obrazach skaterometrycznych przetworzonych metodą nakładania obrazów
Analysis of the dynamic range of the signal content in images of scattered light processed by image stacking
Autorzy:
Kapłonek, W.
Łukianowicz, C.
Powiązania:
https://bibliotekanauki.pl/articles/156449.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
przetwarzanie i analiza obrazu
metoda nakładania obrazów
obraz skaterometryczny
zakres dynamiczny sygnału
chropowatość powierzchni
image processing and analysis
image stacking
image of scattered light
dynamic range of signal
surface roughness
Opis:
W artykule przeanalizowano jedną z cech obrazów wynikowych uzyskanych metodą nakładania obrazów. Wykorzystano obrazy skaterometryczne rejestrowane w postaci sekwencji video podczas ruchu badanych powierzchni, oświetlanych światłem laserowym o długości fali λ = 635 nm skierowanym pod kątem padania równym 50°. Sekwencje przetwarzano za pomocą specjalistycznego oprogramowania o nazwie RegiStax 4.0, w celu uzyskania pojedynczych obrazów wynikowych o uśrednionej wartości luminacji. Dla różnej liczby nakładanych klatek obserwowano wzrost zakresu dynamicznego sygnału zawartego w obrazie. Cechę tę analizowano na podstawie wyznaczanych histogramów luminacji dla każdego z ocenianych obrazów.
In the paper the theoretical bases of image stacking and the analysis of one of the features of output images obtained by this technique are presented. The authors used the images of scattered light in the form of video sequences acquired during the movement of the tested surfaces which were illuminated by a laser light beam (wavelength λ = 635 nm, incidence angle: 50 degree). The video sequences were processed by RegiStax 4.0 software. The software extracted automatically single frames from a sequence, aligned them and, then, stacked the images to produce an average value of the luminance. In the result of all these operations a single output image was created. For different numbers of the stacking frames there was observed the increase in the dynamic range of the signal content in output images. This feature was analysed on the basis of assessment of the luminance histograms by ImageJ 1.41 software. The increase in the dynamic range of the signal content in images of the scattered light can make it possible to obtain better information on the surface condition and, the same, correct metrological assessment of this surface. The presented method can be applied to in-process inspection of surface parameters and detection of surface defects of machine parts.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 4, 4; 232-235
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A 1.67 pJ/Conversion-step 8-bit SAR-Flash ADC Architecture in 90-nm CMOS Technology
Autorzy:
Khatak, Anil
Kumar, Manoj
Dhull, Sanjeev
Powiązania:
https://bibliotekanauki.pl/articles/1844527.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog to digital converter
ADC
successive approximation register (SAR)
common mode current feedback gain boosting
CMFD-GB
residue amplifier
RA
spurious free dynamic range
SFDR
integral nonlinearity
INL
differential nonlinearity
DNL
Opis:
A novice advanced architecture of 8-bit analog to digital converter is introduced and analyzed in this paper. The structure of proposed ADC is based on the sub-ranging ADC architecture in which a 4-bit resolution flash-ADC is utilized. The proposed ADC architecture is designed by employing a comparator which is equipped with common mode current feedback and gain boosting technique (CMFD-GB) and a residue amplifier. The proposed 8 bits ADC structure can achieve the speed of 140 mega-samples per second. The proposed ADC architecture is designed at a resolution of 8 bits at 10 MHz sampling frequency. DNL and INL values of the proposed design are -0.94/1.22 and -1.19/1.19 respectively. The ADC design dissipates a power of 1.24 mW with the conversion speed of 0.98 ns. The magnitude of SFDR and SNR from the simulations at Nyquist input is 39.77 and 35.62 decibel respectively. Simulations are performed on a SPICE based tool in 90 nm CMOS technology. The comparison shows better performance for this proposed ADC design in comparison to other ADC architectures regarding speed, resolution and power consumption.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 3; 347-354
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic response analysis of drill pipe considering horizontal movement of platform during installation of subsea production tree
Autorzy:
Wang, Fei
Chen, Neng
Powiązania:
https://bibliotekanauki.pl/articles/1585045.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
SPT installation
drill pipe
dynamic response
vibration range
bending stress
Opis:
In order to study the dynamic response of a drill pipe under the motion of the float platform, current and waves during the installation of a subsea production tree (SPT), a numerical model was established to analyse the mechanical properties of the drill pipe. The effects of the float platform motion on the mechanical behaviours of the drill pipe are carried out as well as the operation depth, submerged weight of the SPT, current velocity and drill pipe specification. At the same time, the evolution mechanism of the dynamic response of the drill pipe was also explored. The results show that the bending stress of the drill pipe approaches the maximum value when the platform moves to about one fourth of its period. Based on the research, the deeper the operation depth, the smaller the range of motion of the bottom of the drill pipe; the current velocity and the size of drill pipe have the greatest influence on the lateral displacement and bending stress.
Źródło:
Polish Maritime Research; 2020, 3; 22-30
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the vibration propagation in the subsoil
Autorzy:
Jastrzębska, M.
Łupieżowiec, M.
Uliniarz, R.
Jaroń, A.
Powiązania:
https://bibliotekanauki.pl/articles/178665.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
soil characteristics in small strain range
triaxial tests
dynamic analysis
Opis:
The paper presents in a comprehensive way issues related to propagation in a soil environment of vibrations originating during sheet piling vibratory driving. Considerations carried out comprised the FEM analysis of initial-boundary behaviour of the subsoil during impacts accompanying the works performed. The analysis has used the author’s RU+MCC constitutive model, which can realistically describe complex deformation characteristics in soils in the field of small strains, which accompany the phenomenon of shock propagation. The basis for model creation and for specification of material parameters of the presented model consisted of first-class tests performed in a triaxial apparatus using proximity detectors guaranteeing a proper measurement of strains ranging from 10(–1) to 10(–3) % and bender elements. Results obtained from numerical analyses were confronted with results of field tests consisting in measurements of acceleration amplitudes generated on the ground surface due to technological impacts versus the distance from vibration source.
Źródło:
Studia Geotechnica et Mechanica; 2014, 36, 3; 9-19
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Range Identification for a Perspective Dynamic System with a Single Homogeneous Observation
Autorzy:
Ma, L.
Chen, Y.
Moore, K. L.
Powiązania:
https://bibliotekanauki.pl/articles/908492.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system identyfikacji
układ dynamiczny
obserwator nieliniowy
range identification
perspective dynamic systems
nonlinear observer
Opis:
Perspective problems arise in machine vision when using a camera to observe the scene. Essential problems include the identification of unknown states and/or unknown parameters from perspective observations. Range identification is used to estimate the states/positions of a moving object with known motion parameters. Range estimation has been discussed in the literature using nonlinear observers with full homogeneous observations derived from the image plane. In this paper, the same range identification problem is discussed with a single homogeneous observation using nonlinear observers. Our simulation results verify the convergence of the observers when their observability conditions are satisfied.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2005, 15, 1; 63-72
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-15 z 15

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