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Wyszukujesz frazę "Fan, Jun" wg kryterium: Autor


Tytuł:
Research on Scattering Feature Extraction of Underwater Moving Cluster Targets Based on the Highlight Model
Autorzy:
Yang, Yang
Fan, Jun
Wang, Bing
Tematy:
motion small cluster targets
feature fusion
azimuth trend scale
azimuth trend Doppler
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Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/31339855.pdf  Link otwiera się w nowym oknie
Opis:
In detecting cluster targets in ports or near-shore waters, the echo amplitude is seriously disturbed by interface reverberation, which leads to the distortion of the traditional target intensity characteristics, and the appearance of multiple targets in the same or adjacent beam leads to fuzzy feature recognition. Studying and extracting spatial distribution scale and motion features that reflect the information on cluster targets physics can improve the representation accuracy of cluster target characteristics. Based on the highlight model of target acoustic scattering, the target azimuth tendency is accurately estimated by the splitting beam method to fit the spatial geometric scale formed by multiple highlights. The instantaneous frequencies of highlights are extracted from the time-frequency domain, the Doppler shift of the highlights is calculated, and the motion state of the highlights is estimated. Based on the above processing method, target highlights’ orientation, spatial scale and motion characteristics are fused, and the multiple moving highlights of typical formation distribution in the same beam are accurately identified. The features are applied to processing acoustic scattering data of multiple moving unmanned underwater vehicles (UUVs) on a lake. The results show that multiple small moving underwater targets can be effectively recognized according to the highlight scattering characteristics.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation and Modelling on the Shipping Noise in Shallow Waters with Complex Islands and Reefs of the East China Sea
Autorzy:
Peng, Zilong
Zhou, Fulin
Fan, Jun
Wang, Bin
Wen, Huabing
Tematy:
shipping noise
spectral source level
noise mapping
shallow water
merchant ship
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Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/1953475.pdf  Link otwiera się w nowym oknie
Opis:
The impact of the noise radiated from merchant ships on marine life has become an active area of research. In this paper, a methodology integrating observation at a single location and modelling the whole noise field in shallow waters is presented. Specifically, underwater radiated noise data of opportunistic merchant ships in the waters of Zhoushan Archipelago were collected at least one day in each month from January 2015 to November 2016. The noise data were analyzed and a modified empirical spectral source level (SSL) model of merchant ships was proposed inspired by the RANDI-3 model (Research Ambient Noise Directionality) methodology. Then combining the modified model with the realistic geoacoustic parameters and AIS data of observed merchant ships, the noise mappings in this area were performed with N × 2D of Normal Mode calculations, in which the SSL of each ship was estimated using the modified model. The sound propagation at different receiving positions is different due to the shielding effect of islands and bottom topography. The methodology proposed in this paper may provide a reference for modelling shipping noise in shallow waters with islands and reefs.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Performance Optimization of Turbulent Self-Noise Suppression and Sound Transmission of Acoustic Windows Made from Functionally Graded Material
Autorzy:
Li, Bing
Zhou, Fu-Lin
Fan, Jun
Wang, Bin
Tan, Liwen
Tematy:
functionally graded material
acoustic window
turbulent self-noise
sound transmission loss
optimization
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Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/31339793.pdf  Link otwiera się w nowym oknie
Opis:
For a simplified sonar dome model, an optimization method for internal gradients of functionally graded material (FGM) acoustic windows is proposed in this paper. This method can be used to design optimized FGM acoustic windows with better turbulent self-noise suppression and sound transmission performances. A theoretical model of FGM acoustic windows to evaluate the reduction of self-noise caused by the turbulent boundary layer (TBL) pulsating pressure and the sound transmission loss (STL) is derived through the double Fourier transform and the wavenumber frequency spectrum analysis, respectively, based on the transfer matrix idea and the classical elastic theory. The accuracy of the theory is verified by the finite element results of COMSOL Multiphysics. Utilizing the genetic algorithm (GA) and taking the monotonic gradient as the constraint condition, the internal gradient optimization method of FGM acoustic windows obtains the optimization variables in the Bernstein polynomial when the optimization objective is minimized by iterating the optimization variables in the deviation function represented by the Bernstein polynomial that is introduced in the gradient function. The STL, the turbulent self-noise reduction or a weighting function of the STL and turbulent self-noise reduction of FGM acoustic windows is chosen as the optimization objective. The optimization calculation of the sound transmission or turbulent self-noise suppression performances is carried out for the FRP-rubber FGM (FGM with fiber reinforced plastic (FRP) as the substrate material and rubber as the top material) acoustic window. The optimized results show that both the sound transmission and turbulent self-noise suppression performance are effectively improved, which verifies the effectiveness of the optimization method. Finally, the mechanism of the sound transmission and self-noise suppression characteristics before and after optimization are explained and analyzed based on the equivalent model of graded materials. The research results of this paper provide a reference value for the future design of FGM acoustic windows for sonar domes.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Normal Mode Solutions of Target Strengths of Solid-filled Spherical Shells and Discussion of Influence Parameters
Autorzy:
Jia, Bing
Fan, Jun
Li, Gui-Juan
Wang, Bin
Chen, Yun-Fei
Tematy:
solid-filled spherical shell
room temperature vulcanized silicone rubber
target strength enhancement
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Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/31339751.pdf  Link otwiera się w nowym oknie
Opis:
The normal mode solution for the form function and target strength (TS) of a solid-filled spherical shell is derived. The calculation results of the spherical shell’s acoustic TS are in good agreement with the results of the finite element method (FEM). Based on these normal mode solutions, the influences of parameters such as the material, radius, and thickness of the inner and outer shells on the TS of a solid-filled spherical shell are analyzed. An underwater spherical shell scatterer is designed, which uses room temperature vulcanized (RTV) silicone rubber as a solid filling material and does not contain a suspension structure inside. The scatterer has a good TS enhancement effect.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of a new type of high-strength monolithic square-section concrete columns with spiral stirrups
Autorzy:
Xianchao, Zheng
Liyun, Fan
Zhao, Jun
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/27764924.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, four full-scale concrete columns with high-strength spiral stirrups (HSSS) are constructed and tested under low-cycle repeated loading. The specimens consisted of two cast-in-place columns and two precast concrete columns encased by a partly square steel pipe and bolt bars.The structural analysis of the HSSS columns of precast concrete conducted here is novel, and past experimental data for this are not available.To assess the seismic behavior and failure mechanisms of the new connections, quasi-static tests were carried out on columns prefabricated with them and cast-in-place specimens.The responses of all columns were compared, and the results showed that the failure modes of all columns are the large eccentric damage, and the destruction of all specimens occur at the column foot. The anti-seismic property of the precast HSSS concrete columns was comparable to that of the HSSS cast-in-place columns. A comparison of such performance parameters as energy dissipation and coefficient of ductility revealed that the precast HSSS concrete columns are suitable for use in earthquake zones.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the second largest eigenvalue of a mixed graph
Autorzy:
Zhou, Jun
Fan, Yi-Zheng
Wang, Yi
Tematy:
mixed graph
Laplacian eigenvalue
degree
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Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/743812.pdf  Link otwiera się w nowym oknie
Opis:
Let G be a mixed graph. We discuss the relation between the second largest eigenvalue λ₂(G) and the second largest degree d₂(G), and present a sufficient condition for λ₂(G) ≥ d₂(G).
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Disintegration of sludge by a two-stage treatment with hydrogen peroxide and solid-state fermentation by Aspergillus oryzae CGMCC5992
Autorzy:
Guan, G.
Zhicai, Z.
Jun, J.
Fan, F.
Keping, C.
Tematy:
Aspergillus oryzae CGMCC5992
fermentation
lignin peroxidase
manganese peroxidase
solid state fermentation
wastewater sludge
wastewater treatment plants
lignina peroksydazy
mangan peroksydazy
podłoże organiczne
fermentacja w stanie stałym
osady ściekowe
oczyszczalnie ścieków
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/208076.pdf  Link otwiera się w nowym oknie
Opis:
A novel and safe method has been reported for wastewater sludge treatment, the first step of which is H2O2 pretreatment at 150 cm3kg for 80 min. In this step, the majority of organic substrate was degraded, and the shear stress diminished significantly. In the second step, Aspergillus oryzae further decomposed the organic substrate of sludge for 8 days, and the activities of manganese peroxidase and lignin peroxidase kept increasing. By the methods, the residual chemical oxygen demand (COD) in the sludge was much lower than that in the sludge treated with high doses of H2O2. These results indicate that the present study provides a feasible method to safely dispose sludge from the wastewater treatment plant.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Improved Generative Design Approach based on Graph Grammar for Pattern Drawing
Autorzy:
Liu, Yufeng
Zhou, Yangchen
Yang, Fan
Li, Song
Wu, Jun
Tematy:
generative design
graph grammar
shape grammar
node transformation rules
pattern drawing
Pokaż więcej
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Instytut Informatyki Technicznej
Powiązania:
https://bibliotekanauki.pl/articles/59122876.pdf  Link otwiera się w nowym oknie
Opis:
Generative design is used to efficiently generate design solutions with powerful computational methods. Generative design based on shape grammar is currently the most commonly used approach, but it is difficult for shape grammar to formally analyze the generated pattern. Graph grammar derived from one-dimensional character grammar is mainly used for generating and analyzing abstract models of visual languages. However, there is a significant gap between the generated node-edge graphs and the representation of shape appearance. To address these problems, we propose an improved generative design approach based on virtual-node based continuous Coordinate Graph Grammar (vcCGG). This approach defines a new type of grammatical rule named node transformation rules to convert nodes into shapes with node transformation applications. By combining node transformation applications and L-applications in vcCGG, we can generate a node-edge graph as the structure of the pattern through L-applications, and then draw the shape outline, next adjust the positions of these shapes, thus relating abstract structures and the physical layouts of visual languages. At the end of the paper, we provide an example application of this approach: generating an illustration from Emma Talbot using a combination of node transformation applications and L-applications.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption of methylamine cations on kaolinite basal surfaces : A DFT study
Autorzy:
Chen, Jun
Min, Fan-fei
Liu, Ling-yun
Jia, Fei-fei
Tematy:
kaolinite
methylamine cations
density functional theory
competitive adsorption
adsorption mechanism
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/949692.pdf  Link otwiera się w nowym oknie
Opis:
To explore the interaction of alkylamine surfactants with kaolinite, the density functional theory (DFT) method was used to calculate the single adsorption of different methylamine cation on kaolinite basal surfaces and the competitive adsorption of methylamine cation and water molecule on kaolinite basal surfaces, respectively. Different methylamine cations can adsorb on kaolinite basal surfaces by electrostatic interaction and hydrogen bonds, and the methylamine cations more easily adsorbed on kaolinite Si-O surface. In the case of competitive adsorption with water molecule, the methylamine cation is capable of flushing out the surrounding water molecule to get rid of its steric effect and stably adsorbing on kaolinite basal surfaces, and the adsorption state of the competitive adsorption system is more stable. The adsorption mechanism of methylamine cation on kaolinite basal surface should be the result of electrostatic interaction and hydrogen bonds, and the electrostatic interaction plays the main role.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:
Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Tematy:
straightness
parallelism
laser measurement system
machine tool
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/1849049.pdf  Link otwiera się w nowym oknie
Opis:
A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Dostawca treści:
Biblioteka Nauki
Artykuł

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