Wyniki wyszukiwania - Biblioteka Nauki

1

A review of the genus Macrocheilus HOPE (Coleoptera: Carabidae: Helluonini) of China, with descriptions of seven new species

100%

Zhao D. , Tian M.

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2010

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tom 79

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nr 1

EN

In the present paper a review of the genus Macrocheilus HOPE, 1838 (Coleoptera: Carabidae: Helluonini) of China is provided, with descriptions of seven new species, viz. M. parvimaculatus sp. nov., M. gigas sp. nov., M. fuscipennis sp. nov., M. solidipalpis sp. nov., M. cheni sp. nov., M. quadratus sp. nov., and M. sinuatilabris sp. nov.. A key to all species found in China is also given. In addition, M. asteriscus White is reported from Laos, Indonesia and India for the first time.

2

Open set lattices of subspaces of spectrum spaces

100%

Nai Y. T. , Zhao D.

Demonstratio Mathematica

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2015

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tom Vol. 48, nr 4

637--652

EN

We take a unified approach to study the open set lattices of various subspaces of the spectrum of a multiplicative lattice L. The main aim is to establish the order isomorphism between the open set lattice of the respective subspace and a sub-poset of L. The motivating result is the well known fact that the topology of the spectrum of a commutative ring R with identity is isomorphic to the lattice of all radical ideals of R. The main results are as follows: (i) for a given nonempty set S of prime elements of a multiplicative lattice L, we define the S-semiprime elements and prove that the open set lattice of the subspace S of Spec(L) is isomorphic to the lattice of all S-semiprime elements of L; (ii) if L is a continuous lattice, then the open set lattice of the prime spectrum of L is isomorphic to the lattice of all m-semiprime elements of L; (iii) we define the pure elements, a generalization of the notion of pure ideals in a multiplicative lattice and prove that for certain types of multiplicative lattices, the sub-poset of pure elements of L is isomorphic to the open set lattice of the subspace M ax(L) consisting of all maximal elements of L.

3

The RC Circuit Described by Local Fractional Differential Equations

80%

Zhao X.-H. , Zhang Y. , Zhao D. , Yang X.

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tom Vol. 151, nr 1/4

419--429

EN

A non-differentiable resistor-capacitor circuit comprised of the capacitor and resistor in the fractal-time domain is first proposed in this article. The solution behavior of the corresponding local fractional ordinary differential equation is presented for the Mittag-Leffler decay defined on Cantor sets. The obtained results reveal the sufficiency of the local fractional calculus in the analysis of the fractal electrical systems.

4

Iterative sliding mode observer for sensorless control of five-phase permanent magnet synchronous motor

80%

Yang J. , Dou M. , Zhao D.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2017

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tom Vol. 65, nr 6

845--857

EN

Due to the star connection of the windings, the impact of the third harmonic which does not exist in three-phase permanent magnet synchronous motor (PMSM) cannot be ignored in five-phase PMSM. So the conventional sensorless control methods for three-phase PMSM cannot be applied for five-phase PMSM directly. To achieve the sensorless control for five-phase PMSM, an iterative sliding mode observer (ISMO) is proposed with the consideration of the third harmonic impact. First, a sliding mode observer (SMO) is designed based on the fivephase PMSM model with the third harmonic to reduce the chattering and obtain the equivalent signal of the back electromotive force (EMF). Then, an adaptive back EMF observer is built to estimate the motor speed and rotor position, which eliminates the low-pass filter and phase compensation module and improves the estimation accuracy. Meanwhile, by iteratively using the SMO in one current sampling period to adjust the sliding mode gains, the sliding mode chattering and estimation errors of motor speed and rotor position are further reduced. Besides, the stability of the SMO and the adaptive back EMF observer are demonstrated in detail by Lyapunov stability criteria. Experiment results verify the effectiveness of the proposed observer for sensorless control of five-phase PMSM.

5

Ultra short-term prediction of pole coordinates via combination of empirical mode decomposition and neural networks

80%

Lei Y. , Zhao D. , Cai H.

Artificial Satellites : Journal of Planetary Geodesy

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2016

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tom Vol. 51, No. 4

149--161

EN

It was shown in the previous study that the increase of pole coordinates prediction error for about 100 days in the future is mostly caused by irregular short period oscillations. In this paper, the ultra short-term prediction of pole coordinates is studied for 10 days in the future by means of combination of empirical mode decomposition (EMD) and neural networks (NN), denoted EMD-NN. In the algorithm, EMD is employed as a low pass filter for eliminating high frequency signals from observed pole coordinates data. Then the annual and Chandler wobbles are removed a priori from pole coordinates data with high frequency signals eliminated. Finally, the radial basis function (RBF) networks are used to model and predict the residuals. The prediction performance of the EMD-NN approach is compared with that of the NN-only solution and the prediction methods and techniques involved in the Earth orientation parameters prediction comparison campaign (EOP PCC). The results show that the prediction accuracy of the EMD-NN algorithm is better than that of the NN-only solution and is also comparable with that of the other existing prediction method and techniques.

6

Hierarchical sliding mode control for a class of SIMO under-actuated systems

80%

Qian D. , Yi J. , Zhao D.

Control and Cybernetics

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2008

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tom Vol. 37, no 1

159-175

EN

A hierarchical sliding mode control approach is proposed for a class of SIMO under-actuated systems. This class of under-actuated systems is made up of several subsystems. Based on this physical structure, the hierarchical structure of the sliding surfaces is designed as follows. At first, the sliding surface of every subsystem is defined. Then the sliding surface of one subsystem is defined as the first layer sliding surface. The first layer sliding surface is used to construct the second layer sliding surface with the sliding surface of another subsystem. This process continues till the sliding surfaces of the entire subsystems are included. According to the hierarchical structure, the total control law is deduced by the Lyapunov theorem. In theory, the asymptotic stability of the entire system of sliding surfaces is proven and the parameter boundaries of the subsystem sliding surfaces are given. Simulation results show the feasibility of this control method through two typical SIMO under-actuated systems.

7

Matched-field Source Localization with a Mobile Short Horizontal Linear Array in Offshore Shallow Water

80%

Zhao D. , Huang Z. , Su S. , Li T.

Archives of Acoustics

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2013

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tom Vol. 38, No. 1

105--113

EN

Passive source localization in shallow water has always been an important and challenging problem. Implementing scientific research, surveying, and monitoring using a short, less than ten meter long, horizontal linear array has received considerable attention in the recent years. The short array can be conveniently placed on autonomous underwater vehicles and deployed for adaptive spatial sampling. However, it is usually difficult to obtain a sufficient spatial gain for localizing long-range sources due to its limited physical size. To address this problem, a localization approach is proposed which is based on matched-field processing of the likelihood of the passive source localization in shallow water, as well as inter-position processing for the improved localization performance and the enhanced stability of the estimation process. The ability of the proposed approach is examined through the two-dimensional synthetic test cases which involves ocean environmental mismatch and position errors of the short array. The presented results illustrate the localization performance for various source locations at different signal- to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the short array moves at a low speed along a straight line at a certain depth.

8

Study on Adaptive Threshold Segmentation Method Based on Brightness

80%

Zhao D. , Dai X. , Sun G. , Lu T.

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tom R. 88, nr 9b

150-152

EN

Image segmentation is one of the most important steps before the image data analysis, which divided the image into several areas that have strong similarity. With the more and more widely application of the mesh fabric, the quality requirements are more stringent. As the impact of uneven illumination, the image brightness is inconsistent, which bring a great difficulty to the image segmentation of the mesh fabric. In order to eliminate the effect of uneven illumination in the image acquisition of linear CCD camera, the adaptive threshold segmentation method based on brightness is proposed. Compared with the Otsu method, it is better to eliminate the influence of the uneven illumination and provide a good foundation for subsequent data analysis.

PL

Analizowano system segmentacji obrazu polegający na podziale obrazu na obszary o dużym podobieństwie. Przy nierównym naświetleniu powstaje problem segmentacji. Zaproponowano adaptacyjny system progowej segmentacji bazujący na analizie jasności.

9

Identification of Ship Maneuvering Model Using Extended Kalman Filters

80%

Shi C. , Zhao D. , Peng J. , Shen C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2009

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tom Vol. 3, no. 1

105--110

EN

Ship maneuvering models are the keys to the research of ship maneuverability, design of ship motion control system and development of ship handling simulators. For various frames of ship maneuvering models, determining the parameters of the models is always a tedious task. System identification theory can be used to establish system mathematical models by the system’s input data and output data. In this paper, based on the analysis of ship hydrodynamics, a nonlinear model frame of ship maneuvering is established. System identification theory is employed to estimate the parameters of the model. An algorithm based on the extended Kalman filter theory is proposed to calculate the parameters. In order to gain the system’s input and output data, which is necessary for the parameters identification experiment, turning circle tests and Zig-zag tests are performed on shiphandling simulator and the initial data is collected. Based on the Fixed Interval Kalman Smoothing algorithm, a pre-processing algorithm is proposed to process the raw data of the tests. With this algorithm, the errors introduced during the measurement process are eliminated. Parameters identification experiments are designed to estimate the model parameters, and the ship maneuvering model parameters estimation algorithm is extended to modify the parameters being estimated. Then the model parameters and the ship maneuvering model are determined. Simulation validation was carried out to simulate the ship maneuverability. Comparisons have been made to the simulated data and measured data. The results show that the ship maneuvering model determined by our approach can seasonably reflect the actual motion of ship, and the parameter estimation procedure and algorithms are effective.

10

Extreme learning machine for the predictions of length of day

80%

Lei Y. , Zhao D. , Cai H.

Artificial Satellites : Journal of Planetary Geodesy

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2015

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tom Vol. 50, No. 1

19--33

EN

This work presents short- and medium-term predictions of length of day (LOD) up to 500 days by means of extreme learning machine (ELM). The EOP C04 time-series with daily values from the International Earth Rotation and Reference Systems Service (IERS) serve as the data basis. The influences of the solid Earth and ocean tides and seasonal atmospheric variations are removed from the C04 series. The residuals are used for training of the ELM. The results of the prediction are compared with those from other prediction methods. The accuracy of the prediction is equal to or even better than that by other approaches. The most striking advantages of employing ELM instead of other algorithms are its noticeably reduced complexity and high computational efficiency.

11

RAB11A mediates the proliferation and motility of esophageal cancer cells via WNT signaling pathway

80%

Zhao D. , Wang B. , Chen H.

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tom 67

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nr 4

12

Identification and characterization of porcine parvovirus in Hunan province, China

80%

Zhao D. , Yan M. , Yu X.

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tom 76

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nr 09

EN

Porcine parvovirus (PPV) is considered one of the most important infectious agents of reproductive failure in sows. Little information, however, is available on its prevalence in healthy fattening pigs. Therefore, in the present study, 197 fecal swabs, 197 nasal swabs, 389 serum samples, and 310 lung samples were collected from pigs aged 10-25 weeks across Hunan, China, and tested for the presence of PPV. PPV DNA was amplified by polymerase chain reaction, demonstrating an overall positivity rate of 7.69%, with a particularly high infection rate of 22.90% in the lungs. A total of five PPV strains (PPV-HuN1-5) were isolated on the basis of cytopathic effects in swine testicular cells, and the near-complete genomes were sequenced and subjected to phylogenetic analysis with reference to reported PPV sequences in GenBank. The five Hunan isolates showed a close relationship with each other and predominantly with reported European PPV strains. Moreover, seven amino acid substitutions were detected within the coding region of the VP2 of PPV-HuNs when compared with that of the Chinese vaccine strain PPV-NJ. The relatively high prevalence of PPV discovered in healthy fattening pigs despite a long-term vaccination program in China, highlights the need for improved prevention, monitoring, and control of related diseases in herds.

13

Cascaded Fresnel digital hologram and its application to watermarking

71%

Deng S. , Liu L. , Lang H. , Zhao D. , Liu X.

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tom Vol. 36, nr 2-3

413-420

EN

A cascaded Fresnel digital hologram (CFDH) is proposed, together with its mathematical derivation. Its application to watermarking has been demonstrated by a simulation procedure, in which the watermark image to be hidden is encoded into the phase of the host image. The watermark image can be deciphered by the CFDH setup, the reconstructed image shows good quality and the error is almost close to zero. Compared with previous technique, this is a lensless architecture which minimizes the hardware requirement, and it is used for the encryption of digital image.

14

20 years of evolutionary analysis of giant panda habitat using ecological landscape patterns of Xiaohegou Nature Reserve

71%

Zhang C. , Wu S. , Zhao D. , Guo Q. , Peng P.

Polish Journal of Environmental Studies

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2015

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tom 24

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nr 3

EN

Discovering how to best protect one of the most endangered animals in the world, giant pandas, has always been an important project in ecological studies. Moreover, researching the living environments of giant pandas and how to recover them is one of the most important elements to these studies. In order to more effectively protect the giant pandas and their habitats, we studied the changing of Xiaohegou nature reserve landscape for 20 years, from 1994 to 2014, based on the landscape ecology theory and “3S” techniques (geographic information systems, GIS; remote sensing, RS; global navigation satellite system, GNSS). Specifically, this paper analyzes factors such as landscape fragmentation, connectivity, disturbance degree, landscape diversity, etc. Accordingly, the research presented divides giant panda habitat into nine landscape types that include: evergreen deciduous broad-leaved mixed forest, secondary broadleaved forest, mixed coniferous and deciduous broad-leaved forests, and coniferous forest, et al. The results show that: 1) before establishing the Xiaohegou Nature Reserve in 1993, deforestation was a serious problem, as the results from the 1994 landscape fragmentation suggest. 2) Logging was rampant before the implementation of the national natural forest protection project that began in 1998. Severe damage was observed on the coniferous forest in giant panda habitat. Yet, from the high level of fragmentation that was observed in the connectivity of giant panda habitat, the results suggest 1994 was the worst. After more than ten years of recovery, from 2001 to 2014, the situation of regarding the habitat’s connectivity appears better than previous years. 3) The habitat has been impacted heavily by human disturbance from 1994 to 2001, although it has shown a slight decrease in this tendency from 2001 to 2014. 4) In the past 20 years, both the diversity and evenness indexes are showing a slow drop tendency. 5) This paper analyzes the changing situation regarding the land category evolution of giant panda habitats. Coniferous forests, the main habitat of giant pandas, decreased 6.37 hm² during these 5 years, with a rate of decrease at 1.27 hm² per annum from 1994 to 1998. In the years that followed, however, the coniferous forest recovered 4.21 hm² over the course of 15 years at the rate of 0.28 hm² per annum from 1999 to 2014, providing a reference for further nature reserve policy development.

15

Application of grey model GM(1, 1) to ultra short-term predictions of universal time

71%

Lei Y. , Guo M. , Zhao D. , Cai H. , Hu D.

Artificial Satellites : Journal of Planetary Geodesy

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2016

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tom Vol. 51, No. 1

19--29

EN

A mathematical model known as one-order one-variable grey differential equation model GM(1, 1) has been herein employed successfully for the ultra short-term (<10days) predictions of universal time (UT1-UTC). The results of predictions are analyzed and compared with those obtained by other methods. It is shown that the accuracy of the predictions is comparable with that obtained by other prediction methods. The proposed method is able to yield an exact prediction even though only a few observations are provided. Hence it is very valuable in the case of a small size dataset since traditional methods, e.g., least-squares (LS) extrapolation, require longer data span to make a good forecast. In addition, these results can be obtained without making any assumption about an original dataset, and thus is of high reliability. Another advantage is that the developed method is easy to use. All these reveal a great potential of the GM(1, 1) model for UT1-UTC predictions.

16

TEO-CFCC Characteristic Parameter Extraction Method for Speaker Recognition in Noisy Environments

71%

Li L. , An D. , Zhao D. , Rong C. , Ma S.

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tom R. 89, nr 2a

118--121

EN

This paper proposes TEO-CFCC characteristic parameter extraction method. Signal phase matching is applied to eliminate speech noise on the basis of CFCC characteristic parameter, and then Teager energy operator is added to the acquisition of CFCC characteristic parameter. In this way TEO-CFCC characteristic parameter is obtained and the energy of speech becomes one of the characteristic parameters for speaker recognition. Experiment results show that the recognition accuracy can reach to 83.2% in a -5dB SNR of vehicle interior noise environment by using TEO-CFCC characteristic parameter.

PL

W artykule przedstawiono metodę wyznaczania parametrów charakterystycznych filtru TEO-CFCC. Zastosowano tu dopasowywanie fazowe sygnału, dla eliminacji z mowy szumów oraz operator Teagera do wyrugowania parametrów. Badania eksperymentalne pokazuję, że dokładność rozpoznania głosu wynosi 83,2% przy -5dB SNR we wnętrzu pojazdu.

17

How potassium content in soil shapes giant panda distribution

61%

Zhao D. , Wang J. , Chen W. , Liu X. , Zhang C. , Peng P.

Polish Journal of Environmental Studies

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2019

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tom 28

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nr 2

EN

Potassium (K), one of main essential macronutrient elements in soil, is vital to the growth and metabolism of giant pandas (Ailuropoda melanoleuca) and its staple food bamboos (SFB). However, it is still unknown how the content of K in soil shapes giant panda distribution. To address this problem, we use geographical information system (GIS) and regression analysis to measure their spatial distribution data and analyze their relationships. Our results show a unimodal relationship between the species richness of SFB and K (R²= 0.90, P<0.01), a significant positive linear correlation relationship between SFB and giant panda (R²= 0.47, P<0.01), and a significant unimodal relationship between the K and giant panda (R²= 0.58, P<0.01). Moreover, results reveal that the giant panda may tend to select habitats with K in the soil ranging from 2.58 to 3.14 (mg/g). Our study also highlights the important effect of the eco-geological environment in shaping the distribution of giant panda. Our study suggests that it is essential to incorporate the beneficial and harmful element factors of an eco-geological environment into wildlife habitat research and management. It should improve on habitat estimation, corridor establishment, and biodiversity conservation.

18

Analysis of correlation between the detection rate of Mycoplasma hyopneumoniae in slaughter pigs and season, climate change, and presence of lung lesions

61%

Li R. C. , Hu Y. L. , Ge M. , Zhao D. , Yang T. T. , Qing R. K. , Yu X. L.

Medycyna Weterynaryjna

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2019

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tom 75

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nr 03

EN

The purpose of this study was to analyze the correlation of the rate of Mycoplasma hyopneumoniae (M. hyo) in slaughter pigs with season, climate change and enzootic pneumonia (EP) lesions. We collected 530 slaughter pig lungs with suspected lesions from two slaughterhouses in different seasons and weather conditions from November 2014 to March 2017 in Changsha Hunan Province, China. The EP lesions of these lungs were quantified, and a PCR analysis was used to detect M. hyo in samples of bronchoalveolar lavage fluid (BALF). Twenty percent, 10%, and 9% of the lung specimens were scored 1-5, 6-10, and ≥ 11, respectively. Additionally, we found that 36% of all BALF samples tested positive for M. hyo. Among the lung specimens collected in winter, 41% scored 1 or more, and 53% tested positive for M. hyo. With respect to seasons, the lung specimens collected in summer showed the least number of EP lesions and the lowest positive testing rate for M. hyo. Of these specimens, 27% scored 1 or more, and 22% tested positive for M. hyo. Additionally, low temperature and fast temperature change (during 10 days before sampling) were associated with a higher rate of M. hyo detection in BALF. There was a positive correlation between the lung EP lesion score and the detection rate of M. hyo in the BALF of slaughter pigs. In conclusion, lung EP lesion scoring in slaughter pigs is of referential value to the evaluation of the dynamics of M. hyo infection in a swine population. It is essential to control the spread of M. hyo by careful management of swine populations, and the prevention and control of M. hyo in fattening pigs is of great significance to the eradication of the disease.

19

Treating simulated nitrate pollution groundwater with different pH by microbial fuel cell

61%

Chen S. , Chen W. , Wang X. , Ding Y. , Zhao D. , Wang J.

Polish Journal of Environmental Studies

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2020

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tom 29

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nr 6

20

Molecular cloning, expression, purification and osteoblasts proliferation activity of sika deer thymosin beta10

61%

Wang J. , Liu M. , Bai X. , Zhang H. , Xu Z. , Zhao Y. , Zhao D.

Polish Journal of Veterinary Sciences

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2017

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tom 20

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nr 4