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Drought is a kind of widely existing nature hazard. There are about 150 drought definitions in the world according to the report from National Drought Mitigation Center of United States of America. Therefore, various drought indices have been developed to depict the drought conditions. However, there is no one index that may be applied to everywhere or in any circumstance. Each index has its own strengths...
The classification and mapping method is vital for many fields of research and has important societal and economic meaning. In this study, we applied QuickBird image to discuss a Multi-scale segmentation method about orchard in Taolin region, Ningxia province in China. Meanwhile, eCognition , as the leading object-oriented software in the world , was used to achieve the goal of classification and...
We consider a delayed predator-prey system with Holling II functional response. Firstly, the paper considers the stability and local Hopf bifurcation for a delayed prey-predator model using the basic theorem on zeros of general-transcendental function, which was established by Cook etc.. Secondly, special attention is paid to the global existence of periodic solutions bifurcating from Hopf bifurcations...
In this paper, we modify OLSR for MANET nodes to achieve full connection to Internet through multiple mobile gateways. We present a proactive mobile IP approach using Hello message and TC message to maintain the MANET nodes movement. The mobile gateway multiple metrics selection algorithm can select the best one among the active multiple mobile gateways. The simulation result shows that our approach...
As for I-shaped profile steel, the flat web is replaced with corrugated web that makes the profile steel have predominant mechanical properties. The key technique of the hot rolling of I-shaped profile steel with wholly corrugated web is the profile design for the tooth-shape rolls of universal finishing stand. Being based on the condition of stabilized rolling and the relationship between corrugated...
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