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	Exploring global food security pattern from the perspective of spatio-temporal evolution 期刊论文 OAI收割 JOURNAL OF GEOGRAPHICAL SCIENCES, 2020, 卷号: 30, 期号: 2, 页码: 179-196 作者: Cai, Jianming; Ma, Enpu; Lin, Jing; Liao, Liuwen; Han, Yan \| 收藏 \| 浏览/下载：21/0 \| 提交时间：2020/05/19 food security assessment spatial pattern changing characteristics multi-nonlinear regression influencing factors
	Exploring global food security pattern from the perspective of spatio-temporal evolution 期刊论文 OAI收割 JOURNAL OF GEOGRAPHICAL SCIENCES, 2020, 卷号: 30, 期号: 2, 页码: 179-196 作者: Cai, Jianming; Ma, Enpu; Lin, Jing; Liao, Liuwen; Han, Yan \| 收藏 \| 浏览/下载：11/0 \| 提交时间：2020/05/19 food security assessment spatial pattern changing characteristics multi-nonlinear regression influencing factors
	A new algorithm of image segmentation for overlapping grain image (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China 作者: Zhang X.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：18/0 \| 提交时间：2013/03/25 Image segmentation is primary issue in image processing at the same time it is principal problem in low level vision in computer vision field. It is the key technology to process image analysis image comprehend and image depict successfully. Aim at measurement of granularity size of nonmetal grain a new algorithm of image segmentation and parameters calculation for overlapping grain image is studied. The hypostasis of this algorithm is present some new attributes of graph sequence from discrete attribute of graph consequently achieve that pick up the geometrical characteristics from input graph and new graph sequence which in favor of image segmentation is recombined. The conception that image edge denoted with "twin-point" is put forward base on geometrical characters of point image edge is transformed into serial edge and on recombined serial image edge based on direction vector definition of line and some additional restricted conditions the segmentation twin-points are searched with thus image segmentation is accomplished. Serial image edge is transformed into twin-point pattern to realize calculation of area and granularity size of nonmetal grain. The inkling and uncertainty on selection of structure element which base on mathematical morphology are avoided in this algorithm and image segmentation and parameters calculation are realized without changing grain's self statistical characters.
	Dispersion compensating properties of microstructure fiber (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Communication, August 21, 2005 - August 26, 2005, Changshun, China 作者: Li C.; Wang W.; Wang W.; Li C.; Li C. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 Microstructure fiber is a new kind of optical fiber. An arrangement of air holes running along the full length of the fiber provides the confinement and guidance of light. The light is confined in the silica core along the fiber axis. This fiber has endlessly single mode special dispersion characteristics and so on. Using a vectorial effective-index numerical method we investigated the dispersion characteristics of a microstructure fiber with honeycomb cladding structures. The dispersion dispersion slope and Kappa parameter can be designed neatly by changing the air hole size and the separation of the holes in fiber cladding. We demonstrated the Microstructure fiber with large absolute value of normal dispersion and negative dispersion slope at the wavelength of 1550nm. Conventional communication non-shifted single-mode fibers and nonzero-dispersion shifted fibers (NZ-DSF) can be compensated efficiently using the microstructure fiber at the wavelength around 1550nm.
	Phase characteristics of laser beam in fibers (EI CONFERENCE) 会议论文 OAI收割 5th International Workshop on Adaptive Optics for Industry and Medicine, August 29, 2005 - September 1, 2005, Beijing, China 作者: Wang L.; Wang L.; Liu J.; Liu J.; Liu J. 收藏 \| 浏览/下载：34/0 \| 提交时间：2013/03/25 The phase changing rates1 of laser beam in single mode polarization maintaining fiber (PMF) Yb-doped rectangular inner cladding dual-clad fiber (DCF) and Yb-doped large-mode-area dual-clad fiber (LMF) are investigated by means of interference under situations with different exterior disturbance for situations that all the fibers are used as transmission medium only as well as amplifying medium with the last two. In this paper phase fluctuation characteristics of the beam transmitted through the fibers with no amplification are presented. The results show that the phase fluctuation frequencies of the laser beam transmitted through these three kinds of fibers are mainly in the range of 100-200Hz 100-300Hz and 80-400Hz respectively in normal laboratory environment. The phase fluctuation frequencies of the laser beam transmitted through the DCF in cases of when the environment temperature is changing a constant pressure is applied to the fiber and when vibration is applied are mainly in the range of 100-600Hz 100Hz-300Hz and 100-500Hz respectively. In the same cases for the LMF the phase fluctuation frequencies are mainly in the range of 150-600Hz 100-400Hz and 100-1000Hz respectively. It indicates that for realizing phase stabilization the bandwidth of any potential phase control2 system has to be in the range of a few kilohertz.