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Wyszukujesz frazę "Zhang, Y. J." wg kryterium: Autor


Tytuł:
Forecast model for real time reliability of storage system based on periodic inspection and maintenance data
Model do prognozowania niezawodności systemu magazynowania w czasie rzeczywistym w oparciu o dane z przeglądów okresowych oraz dane eksploatacyjne
Autorzy:
Su, Ch.
Zhang, Y. J.
Cao, B. X.
Powiązania:
https://bibliotekanauki.pl/articles/301915.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
niezawodność magazynowania
niezawodność w czasie rzeczywistym
okresowe przeglądy i obsługa
dane cenzurowane
storage reliability
real-time reliability
periodic inspection and maintenance
censored data
Opis:
In recent years, storage reliability has attracted much attention for increasing reliability requirement. In this paper, forecast models for real-time reliability of storage system under periodic inspection and maintenance are presented, which is based on the theories of reliability physics and exponential distribution. The models are developed under two newly-defined imperfect repair modes, i.e., Improved As Bad As Old (I-ABAO) and Improved As Good As New (I-AGAN). A completion method for censored life data is also proposed by averaging the residual lifetime. According to the complete and censored lifetime data, parameters in the models are estimated by applying maximum likelihood estimation method and iterative method respectively. A numerical example of a storage system is given to verify the feasibility of the proposed completion method and the effectiveness of the two models.
W ostatnich latach wiele uwagi poświęcono tematyce niezawodności magazynowania w odniesieniu do zwiększania wymogu niezawodności. W prezentowanym artykule, przedstawiono modele do prognozowania w czasie rzeczywistym niezawodności systemu magazynowania podlegającego przeglądom okresowym i obsłudze. Modele oparto na teoriach z zakresu fizyki niezawodności oraz na rozkładzie wykładniczym. Proponowane modele opracowano dla dwóch nowo zdefiniowanych opcji niepełnej odnowy, t.j. Improved-As Bad As Old (Jak Tuż Przed Uszkodzeniem - Wersja Udoskonalona) oraz Improved-As Good As New (Jak Fabrycznie Nowy - Wersja Udoskonalona). Zaproponowano także metodę uzupełniania danych cenzurowanych (uciętych) dotyczących trwałości polegającą na uśrednianiu trwałości resztkowej. Zgodnie z pełnymi i cenzurowanymi danymi trwałościowymi, parametry w proponowanych modelach ocenia się, odpowiednio, z zastosowaniem estymacji metodą największej wiarygodności oraz metody iteracyjnej. Poprawność przedstawionej metody uzupełniania oraz efektywność proponowanych dwóch modeli zweryfikowano na podstawie numerycznego przykładu systemu magazynowania.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 4; 342-348
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of solitary wave in non-uniform fiber system with high-order nonlinear effects
Autorzy:
Xiao, Y.
Zhang, J.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/173308.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
solitary wave
coupled higher-order nonlinear Schrödinger equation
high-order nonlinear effect
Opis:
The ultra-short pulse propagation in a non-uniform fiber system is investigated based on the variable coefficient coupled higher-order nonlinear Schrödinger equation with the dispersion gain and nonlinear gain terms. By using the ansatz method and the split-step Fourier method, we get the exact solitary wave solution, with which the transmission process of the solitary wave is studied. Furthermore we obtain the stability of the solitary wave under finite initial perturbations. The interaction between two neighboring solitary waves is also studied.
Źródło:
Optica Applicata; 2018, 48, 2; 273-284
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of recent coastline evolution due to marine reclamation projects in the Qinzhou Bay
Autorzy:
Yan, Y.
Zhang, Z.
Wang, C.
Zhang, L.
Huang, Y.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/258862.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Qinzhou Bay
marine reclamation
remote sensing
geospatial analysis
coastline evolution
Opis:
Intense marine reclamation activities bring obvious benefits, meanwhile, these activities also influence the coastal natural formation, hydrodynamic processes and water environment etc. In order to investigate the exact influence in the Qinzhou Bay brought by marine reclamation behaviors in recent years, based on the remote sensing image data in the Qinzhou Bay in 2006, 2008, 2009, 2012 and 2014, with the help of GIS and RS software, the thesis interprets Qinzhou Bay coastline and artificial reclamation by man-machine interaction and makes quantitative analysis in the Qinzhou Bay coast evolution recently. The results show: (1) Qinzhou Bay coastal morphology change degree was strong in 2006 - 2012 and the coastline changed greatly. Originally part of the natural shore segments which had twists and turns were gradually filled into artificial coast, the coast constantly advanced to the sea, coastline became regular and straight; (2) The change degree of coastline was relatively small in 2006-2008, the average artificial coastline increased 8.86 km/a, the average artificial reclamation area was 20.79 km2 /a; in 2008-2012, the change range of coastline was the greatest, coastline changed most severely, the average artificial coastline increased 16.07 km/a, the average artificial reclamation area was 58.52 km2 /a; however, in 2012-2014, coastline change degree relatively slowed, the average artificial coastline increased 4.04 km per year, the average artificial reclamation area was 3.464 km2 /a. (3) Compared to the studies of predecessors, the innovation of this paper is that it is the first to carry out the detailed research on coastline evolution caused by reclamation engineerings of the Qinzhou Bay, then formed the change results on coastline that caused by intense human activities in the Qinzhou Bay, provided the area of the marine environment protection with full and accurate data.
Źródło:
Polish Maritime Research; 2017, S 2; 188-194
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and experimental study of SCR injection system
Autorzy:
Du, J.
Zhang, Y.
Cai, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260223.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ammonia grille
flow field
uniformity
SCR test
the denitrification rate
Opis:
According to actual engineering test, we design a linear controlled spray ammonia grille, and apply it to the SCR injection system of ship tail gas treatment. In this paper, the geometric model of ammonia injection grid was built in the flue of diesel engine, and the effects of spray atomization, ammonia uniformity and urea droplet distribution on spray atomization were simulated. Then the test bench was set up to observe the injection status of the ammonia injection grille. The NOx content of the outlet was measured by the original data of the flue gas, and the experimental data were processed. We calculate the denitrification rate by taking the average value to verify the correctness of the spray ammonia grid scheme.
Źródło:
Polish Maritime Research; 2018, S 2; 49-55
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of performance level on lower limb kinematics during table tennis forehand loop
Autorzy:
Qian, J.
Zhang, Y.
Baker, J. S.
Gu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/307434.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
strefa graniczna
łańcuch kinematyczny
sport
lower limb drive
contact area
stretch-shortening cycle
kinetic chain
Opis:
Understanding of biomechanics is important in performance development since each skill has a fundamental mechanical structure. The purpose of this study was to investigate differences in lower limb kinematics during table tennis forehand loop between superior players (SP) and intermediate players (IP). Thirteen male players as superior and thirteen as intermediate participated in this test. A VICON motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematic and contact area data, respectively. Participants were asked to execute single forehand loop against topspin ball with maximal power. Key findings were that SP showed significantly larger hip flexion and knee external rotation at backward-end and larger hip internal rotation and extension at forward-end compared with IP. Contact areas at both events were larger for SP. In addition, SP showed significantly larger joints angular changing rate during forward swing at the ankle and hip. Results indicated that SP possessed better ability of using lower limb drive in forehand loop.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 3; 149-155
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship route planning using historical trajectories derived from AIS Data
Autorzy:
He, Y. K.
Zhang, D.
Zhang, J. F.
Zhang, M. Y.
Li, T. W.
Powiązania:
https://bibliotekanauki.pl/articles/116536.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
AIS Data
Automatic Identification System (AIS)
route planning
historical trajectories
AIS messages
marine traffic
Dijkstra algorithm
ant colony algorithm
Opis:
Ship route planning is one of the key issues in enhancing traffic safety and efficiency. Many route planning methods have been developed, but most of them are based on the information from charts. This paper proposes a method to generate shipping routes based on historical ship tracks. The ship's historical route information was obtained by processing the AIS data. From which the ship turning point was extracted and clustered as nodes. The ant colony algorithm was used to generate the optimize route. The ship AIS data of the Three Gorges dam area was selected as a case study. The ships’ optimized route was generated, and further compared with the actual ship's navigation trajectory. The results indicate that there is space of improvement for some of the trajectories, especially near the turning areas.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 1; 69-76
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New compensation scheme of magneto-optical current sensor for temperature stability improvement
Autorzy:
Chen, J.
Li, H.
Zhang, M.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/221874.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magneto-optical current sensor
normalization
Verdet constant
birefringence
Opis:
A novel magneto-optical current sensor (MOCS) with two sensing arms is proposed to improve the temperature stability. One of the arms, with a highly stable permanent magnet attached and orthogonal to the other one, is designed to provide a reference that follows the temperature characteristics of the sensing material. By a normalization operation between two arms, the temperature drift is compensated adaptively and a sensing output proportional to the measured current can be reached. A dual-input and dual-output structure is specially designed for the reference sensing arm to demodulate the DC Faraday rotation angle. This scheme compensates simultaneously two main temperature influence factors, the Verdet constant and linear birefringence. Validation tests were carried out and are discussed.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 611-616
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occupational Safety and Health Status of Sanitation Workers in Urban Areas: A Pilot Study From Wuhan, China
Autorzy:
Gong, Y.
Yu, J.
Zhang, X.
Liang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/89907.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
occupational safety and health
sanitation workers
urban health
urbanization
bezpieczeństwo i higiena pracy
urbanizacja
pracownik służb komunalnych
Opis:
Sanitation workers' workload increases quickly with rapid urbanization, but there is almost no evidence or policy recommendations for their management in developing countries. This study describes the health status and occupational protection of sanitation workers; it also explores risk factors related to their health status in Wuhan City, China. Three hundred and eighty-five sanitation workers from 54 streets of Wuhan were surveyed. Their prevalence of 2-week illness and arthritis was relatively higher than in the general population in China. Findings related to occupational protection showed that both sanitation workers (users) and their managers (providers) neglected the role of low-cost protection measures, especially masks, soap/hand sanitizer and prejob training (use rate of 7.27%, 26.75% and 43.64%, respectively). High-intensity workload was an important risk factor for 2-week illness, and prejob training was an important protective factor against arthritis.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 3; 435-442
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific emitter identification using geometric features of frequency drift curve
Autorzy:
Zhao, Y.
Wui, L.
Zhang, J.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200575.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
specific emitter identification
geometric features
frequency drift
adaptive fractional spectrogram
support vector machine
emiter
cechy geometryczne
dryf częstotliwości
spektrogram
Opis:
Specific emitter identification (SEI) is a technique for recognizing different emitters of the same type which have the same modulation parameters. Using only the classic modulation parameters for recognition, one cannot distinguish different emitters of a same type. To solve the problem, new features urgently need to be developed for recognition. This paper focuses on the common phenomenon of frequency drift, defines geometric features of frequency drift curve and, finally, proposes a practical algorithm of specific emitter identification using the geometric features. The proposed algorithm consists of three processes: instantaneous frequency estimation based on the adaptive fractional spectrogram, feature extraction of frequency drift curve based on geometric methods for describing a curve and recognition process based on support vector machine. Simulation results show that the identification rate is generally more than 98% above –5 dB of signal to noise ratio (SNR), and real data experiment verifies the practical performance of the proposed algorithm.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 1; 99-108
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new sufficient schedulability analysis for hybrid scheduling
Autorzy:
Zhang, F.
Zhai, Y.
Liao, J.
Powiązania:
https://bibliotekanauki.pl/articles/330353.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
scheduling algorithm
real time system
schedulability analysis
preemptive scheduling
earliest deadline first
fixed priority
algorytm szeregowania
system czasu rzeczywistego
analiza szeregowalności
Opis:
Earliest deadline first (EDF) and fixed priority (FP) are the most commonly used and studied scheduling algorithms for real-time systems. This paper focuses on combining the EDF and FP strategies in one system. We provide a new sufficient schedulability analysis for real-time hybrid task systems which are scheduled by EDF and FP. The proposed analysis has a polynomial time complexity and no restrictions on task parameters, where the relative deadline of each task could be less than, equal to, or greater than its period. By extensive experiments, we show that our proposed analysis significantly improves the acceptance ratio compared with the existing results of the sufficient schedulability test for hybrid scheduling systems.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2016, 26, 3; 683-692
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification Mechanism and Growth Process of Al3(Sc, Zr) Particles in As-cast Al-Si-Mg-Cu-Zr-Sc Alloy
Autorzy:
Li, Y.
Du, X.
Fu, J.
Zhang, Y.
Zhang, Z.
Zhou, S.
Wu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/382672.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solidification process
Al3(Sc, Zr)
three-dimensional morphology
eutectic growth
krzepnięcie stopu
morfologia trójwymiarowa
wzrost eutektyczny
Opis:
In this study, the modification mechanism and growth process of Al3(Sc, Zr) particles in as-cast Al-Si-Mg-Cu based alloy with addition of Sc and Zr were systematically investigated. It was found that 0.57 wt-%Sc addition caused a significant refinement in the average grain size of the investigated alloy, which brought about a remarkable transformation in as-cast microstructure, from thick dendritic shape to fine equiaxed structure. A large amount of primary Al3(Sc, Zr) particles with the dimension of around 5-6 μm were also observed within the equiaxed grain. Due to the identical orientation and similar crystal structure between primary Al3(Sc, Zr) particles and α-Al matrix, the primary particles always served as heterogeneous nucleus for the α-Al matrix. In addition, these cusped cubic primary Al3(Sc, Zr) particles showed triangle, star, rhomboid morphologies are generated from sectioning the particle in (111), (100) and (110) planes, respectively. Particularly, the typical eutectic structure which contained odd number-layer (Al3(Sc, Zr)+α-Al+ ... +Al3(Sc, Zr)) was observed within the investigated particles.
Źródło:
Archives of Foundry Engineering; 2018, 18, 2; 51-56
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic characteristics of magnetic coupling in horizontal axis wave energy device
Autorzy:
Zhang, J.
Liu, Y.
Liu, J.
He, T.
Xie, Y.
Powiązania:
https://bibliotekanauki.pl/articles/258488.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy
magnetic coupling
dynamic characteristics
transfer function
step response
steady state error
Opis:
To solve the dynamic response problems of magnetic coupling in the horizontal axis wave energy device, this has researched the dynamic characteristicsof magnetic coupling. The fitting formula about torque and angle of the magnetic coupling is obtained through experiments. The mathematical models of the magnetic coupling torque transmission are established. The steady state error of the magnetic coupling and the transfer function of the output angle are obtained. The analytical solution of the step response of the output angle in time domain is derived. The influence of the torsional rigidity, the damping coefficient and the driven rotor’s rotational inertia on dynamic characteristics of the magnetic coupling isanalyzed. According to the analysis results, the design rules of magnetic coupling are proposed.
Źródło:
Polish Maritime Research; 2017, S 3; 165-170
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3-aminopropyltriethoxysilane functionalized nanoscale zero-valent iron for the removal of dyes from aqueous solution
Autorzy:
Zhang, J.
Liu, Q.
Ding, Y.
Bei, Y.
Powiązania:
https://bibliotekanauki.pl/articles/779270.pdf
Data publikacji:
2011
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
3-aminopropylotrietoksysilan
żelazo zerowartościowe
separacja magnetyczna
3-aminopropyltriethoxysilane
nano zero-valent iron
acid brilliant scarlet GR
reactive brilliant red K-2BP
magnetic separation
Opis:
Batch studies were conducted to investigate the potential of 3-aminopropyltriethoxysilane modified nano zero-valent iron (APS-NZVI) to adsorb two dyes (acid brilliant scarlet GR and reactive brilliant red K-2BP) from aqueous solution. APS-NZVI showed good adsorption performance for two dyes. Under the adsorption conditions of pH 4.5, initial concentration was 100 mg/L, and time=4h, the maximum adsorption capacities of APS-NZVI were 121.06 mg/g for acid brilliant scarlet GR and 191.5 mg/g for reactive brilliant red K-2BP, respectively. The results revealed that the adsorption behavior of the dyes on the nano-particles fitted well with the Langmuir model and the sorption kinetics fits well the pseudo-second-order rate equation.
Źródło:
Polish Journal of Chemical Technology; 2011, 13, 2; 35-39
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission characteristics of 85Rb and 87Rb laser-induced dichroism atomic filters at 795 nm
Autorzy:
Peng, Y F
Zhang, W J
Powiązania:
https://bibliotekanauki.pl/articles/173843.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
atomic filter
optical anisotropy
narrowband
rubidium
Opis:
The transmission characteristics for 85Rb and 87Rb laser-induced dichroism atomic filters operating on rubidium D1 lines (795 nm) transitions are analyzed. By means of semiclassical density matrix equations of motion, a three-level model for the transmission characteristics of the ground state laser-induced dichroism atomic filter is presented. Calculative results show that this filter, using two counterpropagating pump and probe beams, can obtain higher transmission, narrower bandwidth and larger tuning capability than that using two copropagating pump and probe beams; with the aid of counterpropagating pump, the 85Rb ground state laser-induced dichroism atomic filter can be more effective to achieve higher peak transmission (>34%) and larger tunability (>1 GHz) than the 87Rb ground state laser-induced dichroism atomic filter in the same operation parameters. This result may be helpful for improving peak transmission (14.6%) of Rb ground state laser-induced dichroism atomic filter reported (CERÈ A. et al., Opt. Lett. 34(7), 2009, pp. 1012–1014).
Źródło:
Optica Applicata; 2014, 44, 1; 55-67
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł

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