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浏览/检索结果: 共22条，第1-10条 帮助

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Improving High-Frequency Marine Gravity Anomaly Recovery: The Efficacy of SWOT Wide-Swath Altimetry 期刊论文  OAI收割
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, 2024, 卷号: 21, 页码: 5
作者:  Wang, Jianbo;  Xu, Yongsheng;  Zhang, Qingjun;  Wang, Yan;  Zhu, Chengcheng
  |  收藏  |  浏览/下载：9/0  |  提交时间：2024/12/20
Evaluating influential nodes for the Chinese energy stocks based on jump volatility spillover network 期刊论文  OAI收割
INTERNATIONAL REVIEW OF ECONOMICS & FINANCE, 2022, 卷号: 78, 页码: 81-94
作者:  Huang, Chuangxia;  Zhao, Xian;  Deng, Yunke;  Yang, Xiaoguang;  Yang, Xin
  |  收藏  |  浏览/下载：41/0  |  提交时间：2022/04/02
An Instance-Frequency-Weighted Regularization Scheme for Non-Negative Latent Factor Analysis on High-Dimensional and Sparse Data 期刊论文  OAI收割
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS, 2021, 卷号: 51, 期号: 6, 页码: 3522-3532
作者:  Luo, Xin;  Wang, Zidong;  Shang, Mingsheng
  |  收藏  |  浏览/下载：26/0  |  提交时间：2021/08/20
The FAST Galactic Plane Pulsar Snapshot survey: I. Project design and pulsar discoveries 期刊论文  OAI收割
Research in Astronomy and Astrophysics, 2021, 卷号: 21, 期号: 5, 页码: 38107
作者:  Han, J. L.;  Wang, Chen;  Wang, P. F.;  Wang, Tao;  Zhou, D. J.
  |  收藏  |  浏览/下载：47/0  |  提交时间：2022/06/30
Synchronous X-ray/Optical QPOs from the Black Hole LMXB MAXI J1820+070 期刊论文  OAI收割
Monthly Notices of the Royal Astronomical Society, 2021
作者:  HXMT
  |  收藏  |  浏览/下载：52/0  |  提交时间：2022/02/08
black hole physics  Low Mass X-ray Binaries  accretion  accretion  discs  stars: individual (MAXI J1820+070)  Astrophysics - High Energy  Astrophysical Phenomena  Abstract: We present high-speed optical photometry from SAAO and SALT on the black hole LMXB MAXI J1820+070 (ASSASN-18ey), some of it simultaneous with NICER, Swift and Insight-HXMT X-ray coverage. We detect optical Quasi-Periodic Oscillations (QPOs) that move to higher frequencies as the outburst progresses, tracking both the frequency and evolution of similar X-ray QPOs previously reported. Correlated X-ray/optical data reveal a complex pattern of lags, including an anti-correlation and a sub-second lag that evolve over the first few weeks of outburst. They also show correlated components separated by a lag equal to the QPO period roughly centered on zero lag, implying that the inter-band variability is strongly and consistently affected by these QPOs at a constant phase lag of roughly ±Ю The synchronisation of X-ray and optical QPOs indicates that they must be produced in regions physically very close to each other  we thus propose that they can be explained by a precessing jet model, based on analogies with V404 Cyg and MAXI J1348-630.  
On the Terrestrial Gamma Ray Flashes Preceding Narrow Bipolar Events 期刊论文  OAI收割
Geophysical Research Letters, 2021, 卷号: 48, 页码: e92160
作者:  HXMT
  |  收藏  |  浏览/下载：24/0  |  提交时间：2022/02/08
low frequency magnetic sferics  narrow bipolar events (NBEs)  relativistic feedback mechanism  Terrestrial Gamma ray Flashes (TGFs)  Abstract: Narrow bipolar events (NBEs) are occasionally reported to occur within a few ms after Terrestrial Gamma ray Flashes (TGFs), while the formation mechanism remains mysterious partially due to the lack of sufficient observations. Here, nine more TGFs of this scenario are reported with concurrent LF sferics and lightning location data. The gamma ray production in these TGFs preceded the occurrence of NBEs by a minimum of 60 µs up to 13.5 ms, and no other fast leader discharge was found within 20 ms before the TGF. The TGF preceded positive NBEs occurred at altitudes of 8.6-11 km in thunderstorms, likely in the high electric field (E field) region of lightning initiation. The analyses show that the NBE preceding TGFs bear harder energy spectrum with larger proportion of high energy photons than EIP related TGFs produced in association with lightning leader. Our findings support the relativistic feedback mechanism of gamma ray generation in the large scale thunderstorm E field.  
Doppler-robust high-spectrum-efficiency VCM-OFDM scheme for low Earth orbit satellites broadband data transmission 期刊论文  OAI收割
IET COMMUNICATIONS, 2018, 卷号: 12, 期号: 1, 页码: 35-43
作者:  Li, Jionghui;  Xiong, Weiming;  Sun, Geng;  Wang, Zhugang;  Huang, Yonghui
  |  收藏  |  浏览/下载：73/0  |  提交时间：2018/03/02
M-estimation for periodic GARCH model with high-frequency data 期刊论文  OAI收割
ACTA MATHEMATICAE APPLICATAE SINICA-ENGLISH SERIES, 2017, 卷号: 33, 期号: 3, 页码: 717-730
作者:  Fan, Peng-ying;  Wu, Si-xin;  Zhao, Zi-long;  Chen, Min
  |  收藏  |  浏览/下载：15/0  |  提交时间：2018/07/30
Design of high speed and parallel compression system used in the big area CCD of high frame frequency (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Precision Engineering and Non-Traditional Machining, PENTM 2011, December 9, 2011 - December 11, 2011, Xi'an, China
作者:  Li G.-N.;  Jin L.-X.;  Zhang R.-F.;  Wang W.-H.;  Li G.-N.
收藏  |  浏览/下载：51/0  |  提交时间：2013/03/25
According to the area CCD camera of characteristics  such as high resolution capacity and high frame frequency  this paper puts forward a high speed and parallel image compression system of high integration degree. Firstly  according to the work principle of the area CCD  FPGA is adopted to realize the timing driving and multichannel and parallel analog signal handling to raise the export frame frequency of the area CCD. Secondly  with an image compression scheme based on FPGA embedded processor MicroBlaze and ADV212 compression chip  real time image compression and the high speed area CCD are realized. Finally  by detecting the analog signal of the area CCD output  the real time compression of the big area CCD image is carried out in different compression ratios and the compression performance is analyzed. Experiment result shows that this scheme can realize real time image compression with the biggest data rate of 520Mbps. When compression bit ratio is 0.15  the signal-to-noise ratio of peak value can reach 36 dB. Image collection and image compression are integrated  which reduces the data transmission between them and improves systematic integration degree.  
The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Wang M.-J.; Wu Z.-G.
收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25
Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity  high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black  the angle of the stripes is uniform  the width of the stripes is uniform  the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE)  the closer a series of data is  the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin  180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those  then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe  60 equal angles are divided in the neighborhood of the angle  then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe  we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn  and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise  an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe  and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest  the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method  the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method  and it can achieve with 15 ms  that satisfying the demand of real time. 2011 SPIE.