This study focuses on the aerodynamic characteristics and flow mechanism of three different configurations of ram-air parafoil with open/closed air inlet and bulges. Firstly, we designed a special parafoil configurati...This study focuses on the aerodynamic characteristics and flow mechanism of three different configurations of ram-air parafoil with open/closed air inlet and bulges. Firstly, we designed a special parafoil configuration for this study. Then we used numerical simulation to obtain the aerodynamic data of three parafoils at different angles of attack, and studied the influence of the bulge and the leading edge open/closed inlet on the aerodynamic performance of the ram-air parafoil. Finally, we study the flow mechanism of the ram-air parafoil through the pressure distribution and flow field. The results of the study show that compared with the aerodynamic parameters of the parafoil without bulges, the optimal angle of attack of the two parafoils with bulges is increased by 4?, the maximum lift to drag ratio of the parafoil with closed leading edge is reduced by about 4.3% and the optimal angle of attack is reduced by about 2?. The maximum lift to drag ratio of the parafoil with open leading edge is reduced by about 23.6% and the stalling angle of attack is reduced by about 4?. The pressure on the surface of a ram-air parafoil with open leading edge inlet is the highest. .展开更多
Remote sensing is an important method for rapidly obtaining farmland information. Once meteorological disaster occurs,using the remote sensing technology to extract disaster area of crops and monitor disaster level ha...Remote sensing is an important method for rapidly obtaining farmland information. Once meteorological disaster occurs,using the remote sensing technology to extract disaster area of crops and monitor disaster level has great significance for evaluating disasters and making a timely remedy. This paper elaborated the importance of monitoring agro-meteorological disasters using remote sensing in current special historical period,overviewed remote sensing methods both at home and abroad,analyzed existing problems,made clear major problems to be solved in monitoring agro-meteorological disasters using remote sensing,and discussed the development prospect of the remote sensing technology.展开更多
This paper presents a new implementation of a high-definition image-processing engine,which mainly targets the 3-dimensional(3D)visualization and stereo video stream display of binocular display equipment.The engine i...This paper presents a new implementation of a high-definition image-processing engine,which mainly targets the 3-dimensional(3D)visualization and stereo video stream display of binocular display equipment.The engine is compatible with the mainstream analog and digital stereo videos in component format and is able to receive stereo composite video broadcast signals using an integrated analog stereo video decoder.The four modules include a spatiotemporal scaling transform engine,a 2D–3D converter,an image animating engine,and a 2D scalar operating in pipeline architecture to implement the video format conversion and the stereo effect enhancement.Furthermore,the data access,hardware structure,and system-level configurations are optimized.Finally,the proposed architecture is realized by 0.18 lm CMOS technology.The application-specific integrated circuit verification results show that the engine can generate a strong feeling of 3D immersion and highdefinition image quality with minimal flicker.The chip has wide compatibility and an uppermost 1080P-processing capacity,which has approximately 3.5 million gates with about 43 mm2 die size.展开更多
文摘This study focuses on the aerodynamic characteristics and flow mechanism of three different configurations of ram-air parafoil with open/closed air inlet and bulges. Firstly, we designed a special parafoil configuration for this study. Then we used numerical simulation to obtain the aerodynamic data of three parafoils at different angles of attack, and studied the influence of the bulge and the leading edge open/closed inlet on the aerodynamic performance of the ram-air parafoil. Finally, we study the flow mechanism of the ram-air parafoil through the pressure distribution and flow field. The results of the study show that compared with the aerodynamic parameters of the parafoil without bulges, the optimal angle of attack of the two parafoils with bulges is increased by 4?, the maximum lift to drag ratio of the parafoil with closed leading edge is reduced by about 4.3% and the optimal angle of attack is reduced by about 2?. The maximum lift to drag ratio of the parafoil with open leading edge is reduced by about 23.6% and the stalling angle of attack is reduced by about 4?. The pressure on the surface of a ram-air parafoil with open leading edge inlet is the highest. .
基金Supported by Key Application Technological Innovation Project of Agriculturein Shandong Province"Monitoring,Early Warning and Evaluation Technical Research of Corn Floods Based on Remote Sensing Data"Special Fund Project for Informationization(E-government)of Shandong Province"Construction of Agricultural Monitoring through Remote Sensing in Shandong Province"+1 种基金Special Project for Autonomous Innovation of Shandong Province(2012CX90204)Key Sci-tech Innovation Project of Shandong Academy of Agricultural Sciences(2014CXZ09-2)
文摘Remote sensing is an important method for rapidly obtaining farmland information. Once meteorological disaster occurs,using the remote sensing technology to extract disaster area of crops and monitor disaster level has great significance for evaluating disasters and making a timely remedy. This paper elaborated the importance of monitoring agro-meteorological disasters using remote sensing in current special historical period,overviewed remote sensing methods both at home and abroad,analyzed existing problems,made clear major problems to be solved in monitoring agro-meteorological disasters using remote sensing,and discussed the development prospect of the remote sensing technology.
基金supported by the Important Specific Projects of National Science and Technology of China(2009ZX01033-001-010)
文摘This paper presents a new implementation of a high-definition image-processing engine,which mainly targets the 3-dimensional(3D)visualization and stereo video stream display of binocular display equipment.The engine is compatible with the mainstream analog and digital stereo videos in component format and is able to receive stereo composite video broadcast signals using an integrated analog stereo video decoder.The four modules include a spatiotemporal scaling transform engine,a 2D–3D converter,an image animating engine,and a 2D scalar operating in pipeline architecture to implement the video format conversion and the stereo effect enhancement.Furthermore,the data access,hardware structure,and system-level configurations are optimized.Finally,the proposed architecture is realized by 0.18 lm CMOS technology.The application-specific integrated circuit verification results show that the engine can generate a strong feeling of 3D immersion and highdefinition image quality with minimal flicker.The chip has wide compatibility and an uppermost 1080P-processing capacity,which has approximately 3.5 million gates with about 43 mm2 die size.