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Wyszukujesz frazę "Zhou, L." wg kryterium: Wszystkie pola


Tytuł:
Precision acoustic navigation for remotely operated vehicles (ROV)
Autorzy:
Zieliński, A.
Zhou, L.
Powiązania:
https://bibliotekanauki.pl/articles/985799.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The ability to navigate a ROV to exact bottom locations or along a precise path is essential to many scientific and engineering tasks. Bottom and water column surveys along a precise and repeatable trajectory allow the monitoring of chemical and physical variables, and the study of sedimentation processes and biological phenomena. Precise navigation is also required for high-resolution synthetic sonar observations and for placement and retrieval of various devices on the bottom. This paper reviews principles behind acoustic navigation and provides a survey of commercially available Ultra-Short Baseline (USBL) navigation systems. A novel high precision navigation system is proposed that offers several advantages over the surveyed systems. Specifically, the precise position and trajectory of a ROV tethered by a cable to a bottom node is obtained using sensitive phase measurement of an acoustic signal. Proof of this concept through shallow-water and deep-water prototypes will be carried out shortly at the University of Victoria.
Źródło:
Hydroacoustics; 2005, 8; 255-264
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocean average current measurement using acoustic phase monitoring
Autorzy:
Zieliński, A.
Zhou, L.
Butowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/331688.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
ocean-related activities
acoustic phase monitoring
hydroacoustic
Opis:
Knowledge of water currents is important in several ocean-related activities. Typically, current speed and direction are measured at a certain fixed location and depth (or depth profile) by a suitable current meter. In this paper, we propose a novel method for average current speed measurement along a path, based on acoustic phase monitoring. In this method, a transmitter and a receiver are installed at the ends of a designated path. A transmitted sinusoidal signal propagates along the path to the receiver. Intervening currents will introduce Doppler frequency shifts that can be measured as a rate of phase change in the received signal. The phase is recovered by means of a phase detector and unwrapping techniques. The desirable feature of the proposed method is that average current speed is monitored along the entire path. Moreover, the estimated frequency shift via the phase measurement achieves a higher accuracy in current measurement than does a measure of frequency directly by an FM demodulator.
Źródło:
Hydroacoustics; 2008, 11; 459-467
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A 2D system approach to the design of a robust modified repetitive-control system with a dynamic output-feedback controller
Autorzy:
Zhou, L.
She, J.
Zhou, S.
Powiązania:
https://bibliotekanauki.pl/articles/330403.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
repetitive control
dynamic output feedback
two dimensional system
singular value decomposition
linear matrix inequality
sterowanie powtarzalne
sprzężenie zwrotne dynamiczne
system dwuwymiarowy
liniowa nierówność macierzowa
Opis:
This paper is concerned with the problem of designing a robust modified repetitive-control system with a dynamic output feedback controller for a class of strictly proper plants. Employing the continuous lifting technique, a continuous-discrete two-dimensional (2D) model is built that accurately describes the features of repetitive control. The 2D control input contains the direct sum of the effects of control and learning, which allows us to adjust control and learning preferentially. The singular-value decomposition of the output matrix and Lyapunov stability theory are used to derive an asymptotic stability condition based on a Linear Matrix Inequality (LMI). Two tuning parameters in the LMI manipulate the preferential adjustment of control and learning. A numerical example illustrates the tuning procedure and demonstrates the effectiveness of the method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2014, 24, 2; 325-334
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Flux Pinning in Single Crystals and Melt-Textured YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$
Autorzy:
Puźniak, R.
Wiśniewski, A.
Baran, M.
Zhou, L.
Powiązania:
https://bibliotekanauki.pl/articles/2012973.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.60.Ge
74.60.Jg
74.72.Bk
Opis:
Flux pinning properties of single crystals and melt-textured samples of YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ were studied for external magnetic field oriented parallel and perpendicular to the CuO$\text{}_{2}$ planes (ab-planes). For H ∥ ab vortex behaviour is mainly determined by a very effective intrinsic pinning mechanism. The irreversibility line is located in the region of higher fields and temperatures in comparison with the irreversibility line for H ⊥ ab. In a single crystal for H ⊥ ab, we observed an increase in the critical current density j$\text{}_{c}$ with magnetic field - the so-called "fishtail effect" - in a very broad temperature range. For H ∥ ab, this effect is observed only at temperatures close to T$\text{}_{c}$, when the intrinsic pinning is much weaker.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 373-376
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust aperiodic-disturbance rejection in an uncertain modified repetitive-control system
Autorzy:
Zhou, L.
She, J.
Li, C.
Pan, C.
Powiązania:
https://bibliotekanauki.pl/articles/330015.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
repetitive control
equivalent input disturbance
two dimensional system
singular value decomposition
linear matrix inequality
sterowanie powtarzalne
układ dwuwymiarowy
rozkład na wartości szczególne
liniowa nierówność macierzowa
Opis:
This paper concerns the problem of designing an EID-based robust output-feedback modified repetitive-control system (ROFMRCS) that provides satisfactory aperiodic-disturbance rejection performance for a class of plants with time-varying structured uncertainties. An equivalent-input-disturbance (EID) estimator is added to the ROFMRCS that estimates the influences of all types of disturbances and compensates them. A continuous-discrete two-dimensional model is built to describe the EID-based ROFMRCS that accurately presents the features of repetitive control, thereby enabling the control and learning actions to be preferentially adjusted. A robust stability condition for the closed-loop system is given in terms of a linear matrix inequality. It yields the parameters of the repetitive controller, the output-feedback controller, and the EID-estimator. Finally, a numerical example demonstrates the validity of the method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 2; 285-295
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on damage detection of base-isolated structure using an adaptive extended Kalman filter
Autorzy:
Yin, Q.
Zhou, L.
Mu, T.
Yang, J. N.
Powiązania:
https://bibliotekanauki.pl/articles/280160.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage detection
adaptive extended Kalman filter
base-isolated structure
Opis:
In this paper, experimental studies are performed and presented to verify the capability of the adaptive extended Kalman filter (AEKF) approach for identifying and tracking damages in nonlinear structures. A base-isolated building model consisting of a scaled building model mounted on a rubber-bearing isolation system has been tested experimentally in the laboratory. The non-linear behavior of the base isolators is represented by the Bouc-Wen model. To simulate the structural damages during the test, an innovative device, referred to as the stiffness element device (SED), is proposed to reduce the stiffness of the upper storey of the structure. Various damage scenarios have been simulated and tested. The measured acceleration response data and the AEKF approach are used to track the variation of the stiffness during the test. The tracking results for the stiffness variations correlate well with that of the referenced values. It is concluded that the AEKF approach is capable of tracking the variation of structural parameters leading to the detection of damages in nonlinear structures.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 4; 1013-1026
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation kinetics and thermodynamic behavior of chalcopyrite and pyrite in high alkaline systems
Autorzy:
Yan, H.
Yuan, Q.
Zhou, L.
Qiu, T.
Ai, G.
Powiązania:
https://bibliotekanauki.pl/articles/110078.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation kinetics
pyrite
chalcopyrite
flotation separation
high alkaline
microcalorimetry
Opis:
The monomineral flotation test and microcalorimetry were used to study the flotation kinetics and thermodynamic behavior of chalcopyrite and pyrite in high alkaline systems of lime and NaOH. The results showed that in these systems there were less hydrophilic substances on the chalcopyrite surface, so that the apparent activation energy of sodium butyl xanthate (SBX) adsorption on chalcopyrite surface was low. This promoted the adsorption of SBX and increased the flotation rate and recovery of chalcopyrite. In contrast, the hydrophilic Fe(OH)3 and SO42- formed by oxidation on the pyrite surface increased the adsorption activation energy of SBX. Thus, the flotation rate and recovery of pyrite were lower. Moreover, in the lime high alkaline system, the hydrophilic calcium film generated on the pyrite surface further hindered the adsorption of SBX, thereby further inhibiting pyrite in this environment. In other words, the lime high alkaline environment increased the apparent activation energy difference of SBX adsorption between chalcopyrite and pyrite compared to the NaOH system, facilitating the flotation separation of chalcopyrite and pyrite. The results can help with the theoretical research of flotation separation of other minerals, and provide guidance for developing low alkaline and lime-free pyrite depressants.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 901-910
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface interaction energy simulation of ceramic materials with epoxy resin
Symulacja energii oddziaływań powierzchni materiałów ceramicznych z żywicą epoksydową
Autorzy:
Fei-Zhou, L.
Zheng-Lin, L.
Zhi-Huai, Y.
Kai, Q.
Powiązania:
https://bibliotekanauki.pl/articles/947496.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
epoxy resin
simulation
interaction energy
ceramic material
żywica epoksydowa
symulacja
energia oddziaływań
materiał ceramiczny
Opis:
A new method to calculate the surface interaction energy of ceramic particles and epoxy resin network was investigated using the Material Studio software solution. Detailed simulations were performed with molecular dynamics (MD) method, using Amorphous Cell module, creating relatively simple surface models of polymer (epoxy resin) and ceramics (Al2O3, SiO2 and SiC). The surface models obtained were used to calculate properties and the surface interaction energy of the materials studied. The computed results are in good agreement with the experimental data, confirming the ability to employ the described simulation method in theoretical evaluation of interaction between various filler or reinforcing materials and the polymer matrix.
Testowano nową metodę obliczania energii oddziaływań powierzchni cząstek ceramicznych z żywicą epoksydową. Obliczenia wykonywano korzystając z oprogramowania Material Studio. Szczegółowe symulacje prowadzono metodą dynamiki molekularnej (MD) za pomocą modułu Amorphous Cell, tworząc modele powierzchni polimeru (żywicy epoksydowej) imateriału ceramicznego (Al2O3, SiO2 lub SiC). Otrzymane modele posłużyły do obliczeń właściwości oraz energii oddziaływań powierzchni badanych materiałów. Uzyskano dobrą zgodność wyników symulacji zdanymi doświadczalnymi, co potwierdziło możliwość zastosowania opisanej metody symulacji do teoretycznej oceny oddziaływania różnych napełniaczy ceramicznych z matrycą polimerową.
Źródło:
Polimery; 2015, 60, 7-8; 468-471
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laboratory investigation of self-healing properties on geosynthetic clay liners with flaw
Autorzy:
Zhang, G.-W.
Zhang, H.-Y.
Wang, J.-F.
Zhou, L.
Liu, P.
Jiang, X.
Powiązania:
https://bibliotekanauki.pl/articles/204652.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
landfills
geosynthetic clay liner
self healing
hydraulic conductivity
Opis:
The objective of this paper is to evaluate the self- healing properties of a commercially-available geosynthetic clay liner (GCL) using flexible-wall permeameter. The GCLs are produced by the same factory, but the contents of bentonite are different. Also the hydraulic conductivities (HC) of GCLs with no defect are different. In this study, specimens were completely saturated under the backpressure of 20 kPa before the test. Permeability tests were performed on GCL specimens with penet rating flaw and also on specimens permeated with distilled water and CaCl2 solutions. The test results were presented and discussed. Experimental results showed that the GCL with penetrating flaw did not exhibit complete self-healing in the case of flaw. After 120 days, the hydraulic conductivity increased by approximately an order of magnitude. In addition, CaCl2 solutions had a significant influence on the hydraulic conductivity. The research findings might be of interest to researchers and engineers who design liners for landfills and other liquid containment facilities.
Źródło:
Archives of Environmental Protection; 2015, 41, 1; 53-58
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Design and the First Test Results of a Fast LTD Stage
Autorzy:
Chen, L.
Zhou, L.
Zou, W.
Ren, J.
Li, Y.
Wu, S.
Xie, W.
Feng, S.
Deng, J.
Powiązania:
https://bibliotekanauki.pl/articles/1807988.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
84.70.+p
52.75.Kq
84.60.Ve
Opis:
Linear transformer driver stages are designed to be used as a primary energy storage in high power pulsed generators. In this report, the design and test results of the linear transformer driver stage prototype that delivers ≈100 kA fast pulse with 133 ns FWHM into a ≈0.87 Ω resistive load are described. This stage consists of 20 (100 kV, 20 nF) storage capacitors that are arranged in 10 identical bricks located evenly around the axis of the stage. Each brick contains two capacitors, a multi-gap switch, and the output connector that transfers the energy to the resistive load. The outer diameter of the stage is ≈1.5 m, at a length of ≈20 cm. The stage is developed to demonstrate the possibility of the fast linear transformer driver technology to create high power pulsed generators.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1186-1188
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Telomerase enhances osteogenic ifferentiation of sheep bone marrow mesenchymal stem cells (BMSCs) by up-regulating PI3K/Akt pathway in vitro
Autorzy:
Zhu, X.
Zhou, L.
Liu, Z.
Chen, X.
Wei, L.
Zhang, Z.
Liu, Y.
Zhu, Y.
Wang, Y.
Yang, X.
Han, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2087304.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bone marrow mesenchymal stem cells
telomerase
proliferation
osteogenic differentiation
PI3K/Akt signalling pathway
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 3; 359-372
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reframing the L2 learning experience as narrative reconstructions of classroom learning
Autorzy:
Hiver, Phil
Obando, Gabriel
Sang, Yuan
Tahmouresi, Somayeh
Zhou, Ashlee
Zhou, Yang
Powiązania:
https://bibliotekanauki.pl/articles/780545.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
L2 learning experience
language learning story interview
qualitative comparative analysis
Opis:
In this study we investigate the situated and dynamic nature of the L2 learning experience through a newly-purposed instrument called the Language Learning Story Interview, adapted from McAdams’ life story interview (2007). Using critical case sampling, data were collected from an equal number of learners of various L2s (e.g., Arabic, English, Mandarin, Spanish) and analyzed using qualitative comparative analysis (Rihoux & Ragin, 2009). Through our data analysis, we demonstrate how language learners construct overarching narratives of the L2 learning experience and what the characteristic features and components that make up these narratives are. Our results provide evidence for prototypical nuclear scenes (McAdams et al., 2004) as well as core specifications and parameters of learners’ narrative accounts of the L2 learning experience. We discuss how these shape motivation and language learning behavior.
Źródło:
Studies in Second Language Learning and Teaching; 2019, 9, 1; 83-116
2083-5205
2084-1965
Pojawia się w:
Studies in Second Language Learning and Teaching
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A counterexample in comonotone approximation in $L^p$ space
Autorzy:
Wu, Xiang
Zhou, Song
Powiązania:
https://bibliotekanauki.pl/articles/1396162.pdf
Data publikacji:
1993
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
Refining the idea used in [24] and employing very careful computation, the present paper shows that for 0 < p ≤ ∞ and k ≥ 1, there exists a function $f ∈ C_{[-1,1]}^k$, with $f^{(k)}(x)≥ 0$ for x ∈ [0,1] and $f^{(k)}(x) ≤ 0$ for x ∈ [-1,0], such that lim sup_{n→∞} (e_n^{(k)}(f)_p) / (ω_{k+2+[1/p]}(f,n^{-1})_{p}) = + ∞ where $e_n^{(k)}(f)_p$ is the best approximation of degree n to f in $L^p$ by polynomials which are comonotone with f, that is, polynomials P so that $P^{(k)}(x)f^{(k)}(x) ≥ 0$ for all x ∈ [-1,1]. This theorem, which is a particular case of a more general one, gives a complete solution to the converse result in comonotone approximation in $L^p$ space for 1 < p ≤ ∞.
Źródło:
Colloquium Mathematicum; 1993, 64, 2; 265-274
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Binary-phase metal-based sandwiched grating with high efficiency
Autorzy:
Wang, B.
Chen, L.
Lei, L.
Zhou, J.
Powiązania:
https://bibliotekanauki.pl/articles/174769.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
binary phase
metal layer
sandwiched grating
Opis:
We describe a novel high efficiency element based on a binary-phase metal-based sandwiched grating, where the binary grating is covered by a dielectric layer and connected by a metal slab on the fused-silica substrate. The modal method is used to optimize the grating duty cycle and period to analyze the feasibility to achieve high efficiency for TE and TM polarizations by effective indices of the modes excited in the grating region. Rigorous coupled-wave analysis (RCWA) is employed to optimize the grating depth and to cover the layer thickness accurately by numerical calculations. It is not easy for the conventional binary grating with a usual duty cycle to achieve high efficiency in the –1st order for TM polarization. For the binary-phase metal-based sandwiched grating, high efficiency can be diffracted into the –1st order for not only TE polarization but also TM polarization. Moreover, the wide fabrication tolerance, the wideband property and the flat surface of easy cleaning should be significant for practical applications in a variety of optical systems.
Źródło:
Optica Applicata; 2013, 43, 3; 607-613
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Antibacterial Activities of Ag/$Nano-TiO_2$ Modified Silicone Elastomer
Autorzy:
Wang, L.
Sun, T.
Zhou, S.
Shao, L.
Powiązania:
https://bibliotekanauki.pl/articles/1215694.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Bf
Opis:
We studied the ability of Ag/$nano-TiO_2$ to inhibit Staphylococcus aureus growth on silicone elastomer material. Ag/$nano-TiO_2$ silicone elastomer was prepared with different concentrations of 0%, 2%, 4%, 6%, 8%, 10%. The antibacterial efficacy of Ag/$nano-TiO_2$ silicone elastomer was determined by the inhibition zone method and the impregnated culture method. The antibacterial timeliness of Ag/$nano-TiO_2$ silicone elastomer was tested by direct contact method. The samples were kept through thermal aging process in an accelerated aging chamber. The effect of concentrations of Ag/$nano-TiO_2$ was insignificant (P < 0.05). There was significant difference between the Ag/$nano-TiO_2$ silicone elastomer and the blank silicone elastomer (P < 0.5). There was also significant difference among specimen groups whose aging periods were 50°C, 100°C, 150°C, 200°C for 87 h (P < 0.5). The silicone elastomer with different concentrations of Ag/$nano-TiO_2$ effectively inhibits Staphylococcus aureus growth.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 248-250
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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