Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Ding, W." wg kryterium: Autor


Wyświetlanie 1-15 z 15
Tytuł:
Design of large-scale streamlined head cars of high-speed trains and aerodynamic drag calculation
Autorzy:
Wu, Z.
Yang, E.
Ding, W.
Powiązania:
https://bibliotekanauki.pl/articles/224065.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high speed train
NURBS
aerodynamic drag
streamlined head car
numerical simulation
pociąg ekspresowy
opór aerodynamiczny
symulacja numeryczna
Opis:
Aerodynamic drag plays an important role in high-speed trains, and how to reduce the aerodynamic drag is one of the most important research subjects related to modern railway systems. This paper investigates a design method for large-scale streamlined head cars of high-speed trains by adopting NURBS theory according to the outer surface characteristics of trains. This method first created the main control lines of the driver cab by inputting control point coordinates; then, auxiliary control lines were added to the main ones. Finally, the reticular region formed by the main control lines and auxiliary ones were filled. The head car was assembled with the driver cab and sightseeing car in a virtual environment. The numerical simulation of train flow field was completed through definition of geometric models, boundary conditions, and space discretization. The calculation results show that the aerodynamic drag of the high-speed train with large-scale streamlined head car decreases by approximately 49.3% within the 50-300 km/h speed range compared with that of the quasi-streamlined high-speed train. This study reveals that the high-speed train with large-scale streamlined head car could achieve the purpose of reducing running aerodynamic drag and saving energy, and aims to provide technical support for the subsequent process design and production control of high-speed train head cars.
Źródło:
Archives of Transport; 2017, 44, 4; 89-97
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bionic shape design of electric locomotive and aerodynamic drag reduction
Autorzy:
Wu, Z.
Huo, Y.
Ding, W.
Xie, Z.
Powiązania:
https://bibliotekanauki.pl/articles/224333.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric locomotive
bionic shape design
aerodynamic drag
numerical simulation
crocodile bionic electric locomotive
lokomotywa elektryczna
bioniczny design
opór aerodynamiczny
symulacja numeryczna
Opis:
Bionics has been widely used in many fields. Previous studies on the application of bionics in locomotives and vehicles mainly focused on shape optimisation of high-speed trains, but the research on bionic shape design in the electric locomotive field is rare. This study investigated a design method for streamlined electric locomotives according to the principles of bionics. The crocodiles were chosen as the bionic object because of their powerful and streamlined head shape. Firstly, geometric characteristic lines were extracted from the head of a crocodile by analysing the head features. Secondly, according to the actual size requirements of the electric locomotive head, a free-hand sketch of the bionic electric locomotive head was completed by adjusting the position and scale of the geometric characteristic lines. Finally, the non-uniform rational B-splines method was used to establish a 3D digital model of the crocodile bionic electric locomotive, and the main and auxiliary control lines were created. To verify the drag reduction effect of the crocodile bionic electric locomotive, numerical simulations of aerodynamic drag were performed for the crocodile bionic and bluff body electric locomotives at different speeds in open air by using the CFD software, ANSYS FLUENT16.0. The geometric models of crocodile bionic and bluff body electric locomotives were both marshalled with three cars, namely, locomotive + middle car + locomotive, and the size of the two geometric models was uniform. Dimensions and grids of the flow field were defined. And then, according to the principle of motion relativity, boundary conditions of flow field were defined. The results indicated that the crocodile bionic electric locomotive demonstrated a good aerodynamic performance. At the six sampling speeds in the range of 40–240 km/h, the aerodynamic drag coefficient of the crocodile bionic electric locomotive decreased by 7.7% on the average compared with that of the bluff body electric locomotive.
Źródło:
Archives of Transport; 2018, 48, 4; 99-109
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of multiple fault test and reliability measures in integrated GPS/INS systems
Autorzy:
Almagbile, A.
Wang, J.
Ding, W.
Knight, N.
Powiązania:
https://bibliotekanauki.pl/articles/130262.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
GPS/INS integration
Kalman filtering
multiple faults
reliability measures
sensitivity analysis
integracja systemów GPS/INS
filtracja Kalmana
uszkodzenia wielokrotne
miary niezawodności
analiza wrażliwościowa
Opis:
Based on Kalman filtering, multi-sensor navigation systems, such as the integrated GPS/INS system, are widely accepted to enhance the navigation solution for various applications. However, such integrated systems do not always provide robust and stable navigation solutions due to unmodelled measurements and system dynamic errors, such as faults that degrade the performance of Kalman filtering for such integration. Single fault detection methods based on least squares (snapshot) method were investigated extensively in the literature and found effective to detect the fault at either sensor level or integration level. However, the system might be contaminated by multiple faults simultaneously. Thus, there is an increased likelyhood that some of the faults may not be detected and identified correctly. This will degrade the accuracy of positioning. In this paper multiple fault test and reliability measures based on a snapshot method were implemented in both the measurement model and the predicted states model for use in a GPS/INS integration system. The influences of the correlation coefficients between fault test statistics on the performances of the faults test and reliability measures were also investigated. The results indicate that the multiple fault test and reliability measures can perform more effectively in the measurement model than the predicted states model due to weak geometric strength within the predicted states model.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2011, 22; 25-37
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of the invasive amphiphyte Alternanthera philoxeroides under different water levels and nitrogen concentrations
Autorzy:
Ding, W.
Zhang, H.
Zhang, F.
Wang, L.
Cui, S.
Powiązania:
https://bibliotekanauki.pl/articles/19911.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2014, 56, 2
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of nitrogen deposition on growth and relationship of Robinia pseudoacacia and Quercus acutissima seedlings
Autorzy:
Ding, W.
Wang, R.
Yuan, Y.
Liang, X.
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/41055.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
nitrogen deposition
plant growth
relationship
Robinia pseudoacacia
Quercus acutissima
seedling
positive interaction
nitrogen fixation
facilitation
competition
Opis:
Increased nitrogen deposition and biological invasions may be two crucial consequences of global change. Exotic plants often have adverse effects on native plants. However, there are reports of occasional positive interaction between them. Increased nitrogen deposition enhances nitrogen availability in soil, which may facilitate the growth of some exotic plant and decrease the competitive advantage of native plants because of their adaptation to low-nutrient environments. Consequently, increased nitrogen deposition may regulate the relationship between exotic and native plants. A greenhouse experiment was, thus, conducted to examine the effects of increased nitrogen deposition on the relationship between the native Quercus acutissima and the exotic Robinia pseudoacacia, which are both widely distributed in North China. Seedlings of both species were grown in monoculture and mixture arrangements in a pot experiment with different nitrogen addition levels (i.e., 0, 2, 5, and 10 g N m–2 a–1). Nitrogen addition altered the biomass partitioning of Q. acutissima and R. pseudoacacia seedlings, with more biomass allocated to leaves and less to roots. Although R. pseudoacacia seedlings always had growth predominance over Q. acutissima seedlings, Q. acutissima was not threatened by R. pseudoacacia at the four levels of nitrogen addition during the three-month duration of the experiment. A positive interaction between the seedlings of R. pseudoacacia and Q. acutissima was found, and increased nitrogen deposition did not affect the positive interaction. Further studies are necessary to determine whether or not R. pseudoacacia is harmful to native ecosystems and should be limited for forestation in North China.
Źródło:
Dendrobiology; 2012, 67
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurable realistic image-based 3D mapping
Autorzy:
Liu, W.
Wang, J.
Wang, J. J.
Ding, W.
Almagbile, A.
Powiązania:
https://bibliotekanauki.pl/articles/130115.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
three-dimensional map
multi-sensor
measurable image
virtual reality
mapa trójwymiarowa
multisensor
rzeczywistość
Opis:
Maps with 3D visual models are becoming a remarkable feature of 3D map services. High-resolution image data is obtained for the construction of 3D visualized models.The3D map not only provides the capabilities of 3D measurements and knowledge mining, but also provides the virtual experienceof places of interest, such as demonstrated in the Google Earth. Applications of 3D maps are expanding into the areas of architecture, property management, and urban environment monitoring. However, the reconstruction of high quality 3D models is time consuming, and requires robust hardware and powerful software to handle the enormous amount of data. This is especially for automatic implementation of 3D models and the representation of complicated surfacesthat still need improvements with in the visualisation techniques. The shortcoming of 3D model-based maps is the limitation of detailed coverage since a user can only view and measure objects that are already modelled in the virtual environment. This paper proposes and demonstrates a 3D map concept that is realistic and image-based, that enables geometric measurements and geo-location services. Additionally, image-based 3D maps provide more detailed information of the real world than 3D model-based maps. The image-based 3D maps use geo-referenced stereo images or panoramic images. The geometric relationships between objects in the images can be resolved from the geometric model of stereo images. The panoramic function makes 3D maps more interactive with users but also creates an interesting immersive circumstance. Actually, unmeasurable image-based 3D maps already exist, such as Google street view, but only provide virtual experiences in terms of photos. The topographic and terrain attributes, such as shapes and heights though are omitted. This paper also discusses the potential for using a low cost land Mobile Mapping System (MMS) to implement realistic image 3D mapping, and evaluates the positioning accuracy that a measureable realistic image-based (MRI) system can produce. The major contribution here is the implementation of measurable images on 3D maps to obtain various measurements from real scenes.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2011, 22; 297-310
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A multiscale methodology for CFD simulation of catalytic distillation bale packings
Autorzy:
Ding, H.
Xiang, W.
Liu, Ch.
Powiązania:
https://bibliotekanauki.pl/articles/780059.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
multiscale model
CFD
reactive distillation
Opis:
A multiscale model for simulating the hydrodynamic behavior of catalytic bale packings has been proposed. This model combines computational fluid dynamics (CFD) and macroscopic calculation. At small scale calculation, the CFD model includes 3-D volume-of-fluid (VOF) simulation within representative elementary unit (REU) under unsteady-state conditions. The REU constitutes gauze and catalyst domain, and porous media model is applied. At large scale calculation, a new mechanistic model deduced from the unit network model is employed. Based on liquid split proportion from small scale calculation, liquid distribution of the entire bale packing can be predicted. To evaluate different packing design, three common bale arrangements, i.e. one-bale, nine-bales and seven-bales, are compared. The area-weighted Christiansen uniformity coefficient is introduced to assess the distribution performance. A comparison between simulation and experimental results is made to validate the multiscale model. The present methodology is proved to be effective to analysis and design of catalytic distillation columns.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 1; 24-32
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relaxing the WDO Assumption in Blind Extraction of Speakers from Speech Mixtures
Autorzy:
Kasprzak, W.
Ding, N.
Hamada, N.
Powiązania:
https://bibliotekanauki.pl/articles/308531.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
blind source extraction
harmonic frequencies
histogram clustering
time-frequency masking
W-disjoint orthogonal
Opis:
The time-frequency masking approach in blind speech extraction consists of two main steps: feature clustering in a space spanned over delay-time and attenuation rate, and spectrogram masking in order to reconstruct the sources. Usually a binary mask is generated under the strong W-disjoint orthogonal (WDO) assumption (disjoint orthogonal representations in the frequency domain). In practice, this assumption is most often violated leading to weak quality of reconstructed sources. In this paper we propose the WDO to be relaxed by allowing some frequency bins to be shared by both sources. As we detect instantaneous fundamental frequencies the mask creation is supported by exploring a harmonic structure of speech. The proposed method is proved to be effective and reliable in experiments with both simulated and real acquired mixtures.
Źródło:
Journal of Telecommunications and Information Technology; 2010, 4; 50-58
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact Solutions and Light Bullet Soliton Solutions of the Two-Dimensional Generalized Nonlinear Schrödinger Equation with Distributed Coefficients
Autorzy:
Huang, W.
Mu, C.
Xu, Y.
Ding, B.
Powiązania:
https://bibliotekanauki.pl/articles/1399167.pdf
Data publikacji:
2013-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.30.Jr
03.65.Ge
05.45.Yv
42.65.Tg
Opis:
A generalized G'/G-expansion method is extended to construct exact solutions to the two-dimensional generalized nonlinear Schrödinger equation with distributed coefficients. Hyperbolic function solution, trigonometric function solution and rational exact solution with parameters are obtained. Selecting parameters and parameter functions properly, novel light bullet soliton solutions with or without the chirp are presented.
Źródło:
Acta Physica Polonica A; 2013, 124, 4; 622-625
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulations of linearly stratified flow past submerged bodies
Autorzy:
Ma, W.
Li, Y.
Ding, Y.
Hu, K.
Lan, L.
Powiązania:
https://bibliotekanauki.pl/articles/259150.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
stratified flow
circular cylinder
internal wave
Suboff
equation of state
Opis:
In this study, a methodology was presented to predict density stratified flows in the near-field of submerged bodies. The energy equation in temperature form was solved coupled with momentum and mass conservation equations. Linear stratification was achieved by the definition of the density as a function of temperature. At first, verifications were performed for the stratified flows passing a submerged horizontal circular cylinder, showing excellent agreement with available experimental data. The ability of the method to cope with variable density was demonstrated. Different turbulence models were used for different Re numbers and flow states. Based on the numerical methods proposed in this paper, the stratified flow was studied for the real scale benchmark DAPRA Suboff submarine. The approach used the VOF method for tracing the free surface. Turbulence was implemented with a k − ω based Detached Eddy Simulation (DES) approach. The effects of submarine speed, depth and density gradient on the free surface wave pattern were quantitatively analyzed. It was shown that, with the increasing of the speed of the submarine, the wavelength and wave height of the free surface wave were gradually increasing. The wave height of the free surface wave was gradually reduced as the submarine’s depth increased. Relative to the speed and submarine depth, the changes of the gradient density gradient have negligible effects on the free surface wave field.
Źródło:
Polish Maritime Research; 2018, S 3; 68-77
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated design of observer based fault detection for a class of uncertain nonlinear systems
Autorzy:
Chen, W.
Khan, A, Q.
Abid, M.
Ding, S. X.
Powiązania:
https://bibliotekanauki.pl/articles/907595.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
detekcja uszkodzeń
obserwator
system nieliniowy
optymalizacja
odporność
fault detection
observer
nonlinear system
optimization
robustness
Opis:
Integrated design of observer based Fault Detection (FD) for a class of uncertain nonlinear systems with Lipschitz nonlinearities is studied. In the context of norm based residual evaluation, the residual generator and evaluator are designed together in an integrated form, and, based on it, a trade-off FD system is finally achieved in the sense that, for a given Fault Detection Rate (FDR), the False Alarm Rate (FAR) is minimized. A numerical example is given to illustrate the effectiveness of the proposed design method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2011, 21, 3; 423-430
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Collosion and Absorption Behaviors of Inclusions on Refractory
Autorzy:
Ding-Guo, Z.
Ming, G.
Xin, L.
Shu-Huan, W.
Powiązania:
https://bibliotekanauki.pl/articles/352357.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inclusion
refractory wall surface
collision and absorption
critical stay speed
Opis:
The paper is dedicated to analysis the inclusion behavior in steel using theoretical calculation and simulation of water. The aim is to establish collision and absorption model of inclusions on refractory. The article discusses the variation of critical stay speed and critical shear with the radius of inclusions in the process of colliding, rebounding and absorbing. The results show the critical stay speed and critical shear of alumina respectively surpasses 1 cm·s-1 and 1 N·m-2, while titanium dioxide separately exceeds 4 cm·s-1 and 10 N·m-2 for the inclusions that radius is less than 2.5 μm. If the inclusions occur rebound after colliding, the inclusions that radius is less than 7 μm will still be absorbed by the surface, while the inclusions that radius is more than 10 μm can easily reenter the steel. The model coincides with the water simulation results and it is of good adaptability.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 857-863
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of Twinned Dendrites of Al-Zn Alloy with High Zn Content
Autorzy:
Gao, K.
Song, W.
Fan, L.
Ding, Y.
Guo, X.
Zhang, R.
Powiązania:
https://bibliotekanauki.pl/articles/351396.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
directional solidification
twinned dendrite
microstructure
growth orientation
deviation angle
Opis:
Twinned dendrites in Al-Zn alloy with high Zn content (40% wt.%) were successfully prepared by directional solidification. At different directional solidification rates (1000 and 1500 μm/s), microstructures and growth orientation variations of Al twinned dendrite and non-twinned dendrite were characterized. By using the inverted trapezoidal graphite sleeve at 1000 μm/s, Al twinned dendrite were formed to developed feather crystal structures in longitudinal section. Its primary and secondary twinned dendrite were grew along [110] direction. Moreover the deviation angle between [110] direction of Al twinned dendrite and the heat flow direction was about 27.15°. While not using the inverted trapezoidal graphite sleeve at 1000 and 1500 μm/s, Al dendrite was the non-twinned dendrite and the twinned dendrite was not appeared. The experimental results showed that the higher temperature gradient, a certain pulling rate and convection environment were the formation conditions of twinned dendrites.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1657-1662
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymorphic analysis of peptide binding domain of major histocompatibility complex class I in domestic ducks
Autorzy:
Yu, S.
Wu, J.
Bai, J.
Ding, Y.
Qiu, W.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/2087551.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
domestic duck
highly variably sites
MHC class I
peptide binding domain
phylogenetic tree
polymorphism
Źródło:
Polish Journal of Veterinary Sciences; 2019, 2; 415-422
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-parameter measurement under fiber bending based on directional resonance coupling in photonic crystal fibers
Autorzy:
Tan, C.
Wang, Q.
Ding, Y.
Li, H.-W.
Wang, M.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/174320.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fiber bending
multi-parameter measurement
photonic crystal fiber
fiber sensing
Opis:
A multi-parameter sensor with enhanced sensitivity based on magnetic fluids infiltrated photonic crystal fiber is proposed. The sensing performances are investigated using the mode coupling theory and finite element method. Four symmetrical defective channels are assembled into the photonic crystal fiber to produce two resonant transmission dips λCV and λCH in vertical and horizontal directions, respectively. Each dip can be split into two relatively shallow dips (λCV1, λCV2 or λCH1, λCH2) when the photonic crystal fiber is bent. Interestingly, the values of (λCH2 – λCH1) and (λCV2 – λCV1) are associated with corresponding bend-curvature but almost unaffected by external temperature or magnetic field. On the contrary, the values of (λCH2 + λCH1)/2 and (λCV2 + λCV1)/2 are sensitive to temperature or magnetic field regardless of the bending condition. Based on above characteristics and the dependence of the magnetic fluids refractive index on temperature and magnetic field, the proposed sensor can measure not only the bend-curvature and bend-direction, but also the temperature and magnetic field.
Źródło:
Optica Applicata; 2018, 48, 3; 449-462
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-15 z 15

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies