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1

Identification of sonar detection signal based on fractional Fourier transform

100%
Wang B., Tang J., Yu F., Zhu Z.
Polish Maritime Research
|
2018
|
tom 25
|
nr Special Issue S2
Aiming at the source of underwater acoustic emission, in order to identify the enemy emission sonar source accurately. Using the digital watermarking technology and combining with the good time-frequency characteristics of fractional Fourier transform (FRFT),this paper proposes a sonar watermarking method based on fractional Fourier transform. The digital watermark embedding in the fractional Fourier transform domain and combined with the coefficient properties of the sonar signal in the fractional Fourier transform to select the appropriate watermark position. Using the different characteristics of the signals before and after embedding, an adaptive threshold was set for the watermark detection to realize the discrimination of sonar signals. The simulation results show the feasibility and has better resolution and large watermark capacity of this method, while the robustness of the watermark is better, and the detection precision is further improved
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

The response of cyclonic eddies to typhoons based on satellite remote sensing data for 2001-2014 from the South China Sea

100%
Yu F., Yang Q., Chen G., Li Q.
Oceanologia
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2019
|
tom 61
|
nr 2
3

Spatial distribution and pollution assessment of potentially toxic elements in urban forest soil of Nanjing, China

100%
Zhang J., Yu F., Pang S., Yu Y.
Polish Journal of Environmental Studies
|
2019
|
tom 28
|
nr 4
Our study aimed to assess the pollution levels and ecological risk of potentially toxic elements (PTEs): Pb, Cd, Cu, Cr, Zn, Ni, and As in the urban forest soil of Nanjing, China. A total of 180 topsoil (0~20cm) samples were collected with the aid of GPS according to 1 × 1 km grid cells in six different function zones: road green belt (RGB), urban square (US), urban garden (UG), institution greenland (IG), residential greenland (RG), and urban rural forest (URF). The concentrations of seven PTEs in study areas were higher than their background values (BVs), and three anthropogenic origins were identified: industrial origin, traffic origin, and agricultural origin by principle analysis (PCA), coupled cluster analysis (CA), and kriging interpolation. The potential ecological risk index (PERI) in the Nanjing urban forest soils was 305.62, in a state of significant pollution, which was mainly due to high contents of Pb, Cd, As, and Zn by correlation analysis. There were three distribution patterns for seven PTEs and PERI: Pb, Cd, As, and PERI presented similar island pattern which took traffic and commercial center as a hot spot (TCIP), while Cr and Ni presented an island pattern that took chemical plants as hotspot (CPIP), and Cu and Zn presented a scattered point pattern (SPP).
4

Methyl-CPG-binding protein 2 [MECP2]: role in development and gene expression

100%
Stratling W. H., Yu F., Thiesen J., Buschdorf J.
Cellular and Molecular Biology Letters
|
2000
|
tom 05
|
nr 2
5
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Calibration of backward-in-time model using drifting buoys in the East China Sea

88%
Yu F., Li J., Zhao Y., Li Q., Chen G.
Oceanologia
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2017
|
tom 59
|
nr 3
In the process of oil exploitation and transportation, large amounts of crude oil are often spilled, resulting in serious pollution of the marine environment. Forecasting oil spill reverse trajectories to determine the exact oil spill sources is crucial for taking proactive and effective emergency measures. In this study, the backward-in-time model (BTM) is proposed for identifying sources of oil spills in the East China Sea. The wind, current and random walk are three major factors in the simulation of oil spill sources. The wind drag coefficient varies along with the uncertainty of the wind field, and the random walk is sensitive to various traits of different regions, these factors are taken as constants in most of the state-of-the-art studies. In this paper, a self-adaptive modification mechanism for drift factors is proposed, which depends on a data set derived from the drifter buoys deployed over the East China Sea shelf. It can be well adapted to the regional characteristics of different sea areas. The correlation factor between predicted positions and actual locations of the drifters is used to estimate optimal coefficients of the BTM. A comparison between the BTM and the traditional method is also made in this study. The results presented in this paper indicate that our method can be used to predict the actual specific spillage locations.
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Floral scent compounds and emission patterns of three Styrax species

88%
Chen C., Cao Y., Chen H., Ni M., Yu F.
Dendrobiology
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2021
|
tom 85
7

The future prospects of arbuscular mycorrhizal fungi in slope ecological restoration

76%
Yan Y., Zhao B., Xu W., Yu F., Liu W., Xia D.
Polish Journal of Environmental Studies
|
2020
|
tom 29
|
nr 3
8

Modelling endogenous leucine flows at the jejunum and ileum in lambs exposed to the intestinal parasite Trichostrongylus colubriformis

76%
Holtrop G., Yu F., Coop R. L., Bruce L. A., Lobley G. E., MacRae J. C.
Journal of Animal and Feed Sciences
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2004
|
tom 13
|
nr 4
589-613
9

Seed predation patterns favor the regeneration of dominant species in forest gaps compared with the understory in an oak-pine mixed forest

76%
Yu F., Shi X., Wang D., Wang T., Yi X., Lou Y.
Acta Theriologica
|
2014
|
tom 59
|
nr 4
Recent studies have demonstrated the higher likelihood of regeneration in forest gaps compared with the understory for the dominant species in pine-oak mixed forest. Here, we tested whether rodent seed predation or dispersal was beneficial for gap regeneration. We tracked the seed predation and dispersal of Quercus aliena var. acuteserrata and Pinus armandii using coded plastic tags in the forest understory close to gaps. Our results demonstrated that the proportions of initial buried seeds of both species were significantly more abundant in the forest understory compared with gaps. After seed caching, however, significantly lower proportions of the seeds of both species survived in the forest understory compared with gaps during the 30-day observation period. The final survival proportions of the seeds cached in the forest understory were lower than those cached in the gaps the next spring, which indicated that small rodents rarely retrieved scatter-hoarded seeds from forest gaps. Our findings suggest that rodent seed predation patterns contribute to the regeneration of the dominant species in gaps compared with the understory in a pine-oak mixed forest. In the study area, reforestation usually involves planting seedlings but direct sowing in forest gaps may be an alternative means of accelerating forest recovery and successional processes.
10
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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An improved Otsu method for oil spill detection from SAR images

76%
Yu F., Sun W., Li J., Zhao Y., Zhang Y., Chen G.
Oceanologia
|
2017
|
tom 59
|
nr 3
In recent years, oil spill accidents have become increasingly frequent due to the development of marine transportation and massive oil exploitation. At present, satellite remote sensing is the principal method used to monitor oil spills. Extracting the locations and extent of oil spill spots accurately in remote sensing images reaps significant benefits in terms of risk assessment and clean-up work. Nowadays the method of edge detection combined with threshold segmenta- tion (EDCTS) to extract oil information is becoming increasingly popular. However, the current method has some limitations in terms of accurately extracting oil spills in synthetic aperture radar (SAR) images, where heterogeneous background noise exists. In this study, we propose an adaptive mechanism based on Otsu method, which applies region growing combined with both edge detection and threshold segmentation (RGEDOM) to extract oil spills. Remote sensing images from the Bohai Sea on June 11, 2011 and the Gulf of Dalian on July 17, 2010 are utilized to validate the accuracy of our algorithm and the reliability of extraction results. In addition, results according to EDCTS are used as a comparator to further explore validity. The comparison with results according to EDCTS using the same dataset demonstrates that the proposed self-adapting algorithm is more robust and boasts high-accuracy. The accuracy computing by the adaptive algorithm is significantly improved compared with EDCTS and threshold method.
11

Agonist-induced activation of human FFA1 receptor signals to extracellular signalregulated kinase 1 and 2 through Gq- and Gi-coupled signaling cascades

64%
Qian J., Gu Y., Wu C., Yu F., Chen Y., Zhu J., Yao X., Bei C., Zhu Q.
Cellular and Molecular Biology Letters
|
2017
|
tom 22
12

A new report of a mosaic dwarf viroid-like disease on mulberry trees in China

64%
Wang W. B., Fei J.-M., Wu Y., Bai X.-C., Yu F., Shi G.-F., Li Y.-F., Kuai Y.-Z.
Polish Journal of Microbiology
|
2010
|
tom 59
|
nr 1
33-36
A viroid-like disease causing mosaic leaves and dwarfism was found on mulberry plants in Zhejiang, China. Grafting of stems from infected plants onto healthy plants resulted in the same symptoms on the healthy plants. A circular small RNA (Mmd-v RNA1) was isolated from the infected plant leaves and caused identical symptoms after more than two years. Nucleotide sequencing indicated that the Mmd-v RNA1 contains 356 nt (GenBank accession no. NC_011362) without viroid characteristic regions, only sharing 30 nt sequence identity with that of the Cherry small circular viroid-like RNA 1 (isolate cscRNAl.150, GenBank accession no. DQ357628). This description is the first of viroid-like RNA infection of mulberry trees.
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