Infrared small target detection is a common task in infrared image processing.Under limited computa⁃tional resources.Traditional methods for infrared small target detection face a trade-off between the detection rate ...Infrared small target detection is a common task in infrared image processing.Under limited computa⁃tional resources.Traditional methods for infrared small target detection face a trade-off between the detection rate and the accuracy.A fast infrared small target detection method tailored for resource-constrained conditions is pro⁃posed for the YOLOv5s model.This method introduces an additional small target detection head and replaces the original Intersection over Union(IoU)metric with Normalized Wasserstein Distance(NWD),while considering both the detection accuracy and the detection speed of infrared small targets.Experimental results demonstrate that the proposed algorithm achieves a maximum effective detection speed of 95 FPS on a 15 W TPU,while reach⁃ing a maximum effective detection accuracy of 91.9 AP@0.5,effectively improving the efficiency of infrared small target detection under resource-constrained conditions.展开更多
Most collision detection algorithms can be efficiently used only with solid and rigid objects, for instance, Hierarchical methods which must have their bounding representation recalculated every time deformation occur...Most collision detection algorithms can be efficiently used only with solid and rigid objects, for instance, Hierarchical methods which must have their bounding representation recalculated every time deformation occurs. An alternative algorithm using particle-based method is then proposed which can detect the collision among non-rigid deformable polygonal models. However, the original particle-based collision detection algorithm might not be sufficient enough in some situations due to the improper particle dispersion. Therefore, this research presents an improved algorithm which provides a particle to detect in each separated area so that particles always covered all over the object. The surface partitioning can be efficiently performed by using LBG quantization since it can classify object vertices into several groups base on a number of factors as required. A particle is then assigned to move between vertices in a group by the attractive forces received from other particles on neighbouring objects. Collision is detected when the distance between a pair of corresponding particles becomes very small. Lastly, the proposed algo- rithm has been implemented to show that collision detection can be conducted in real-time.展开更多
Tracking multiple maneuvering targets remains a challenge due to the existence of clutter and the disturbance of spurious targets. Traditional tracking algorithms treat target measurements as points which results in t...Tracking multiple maneuvering targets remains a challenge due to the existence of clutter and the disturbance of spurious targets. Traditional tracking algorithms treat target measurements as points which results in the loss of information. We have propose a Signature Driven multiple-target Tracking (SDT) method which uses target signature in spectral,spatial and temporary spaces as well as the Markov property of target motion,and the data association process in SDT is very effective. The experimental results have shown its outstanding performance.展开更多
Aiming at alleviating the serious soil erosion, the Chinese government initiated the Sloping Land Conversion Program （SLCP） in 1999. Now; after 8 years of project implementation, the ecological recovery effects of t...Aiming at alleviating the serious soil erosion, the Chinese government initiated the Sloping Land Conversion Program （SLCP） in 1999. Now; after 8 years of project implementation, the ecological recovery effects of the SLCP have become the hot issue of academic circle. This paper; raking the loess hill and gully area of northern Shaanxi as an example, presents a methodology for assessing the vegetation restoration effect of SLCP with normalized difference vegetation index （NDVI）. The key components include calculation of the Growing Season NDVI （GSNDVI）, and estimation of the NVDI change induced by climate and SLCP, respectively. Based on the method, the NDVI change between 2000 and 2006 was obtained using the GSNDVI that excluded the noise from snow and ice. After the part of total NDVI change caused to： climate variation was estimated using empiric formulae, we obtained the part induced by human factors, i.e. the SLCP The human induced part of ND VI change was considered as an approximation indicating the effect of the SLCP on the vegetation. Finally, we analyzed the ND VI change characters of the whole study area, different slope lands and different land use types by spatial statistics method. Results show that the vegetation condition is significantly improved by the SLCP, particularly land types that directly involved in the SLCP, such as steeply slope farmlands, degraded grasslands, etc.展开更多
The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project s...The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.展开更多
AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedu...AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.展开更多
Feature-based image matching algorithms play an indispensable role in automatic target recognition （ATR）. In this work, a fast image matching algorithm （FIMA） is proposed which utilizes the geometry feature of ext...Feature-based image matching algorithms play an indispensable role in automatic target recognition （ATR）. In this work, a fast image matching algorithm （FIMA） is proposed which utilizes the geometry feature of extended centroid （EC） to build affine invariants. Based on at-fine invariants of the length ratio of two parallel line segments, FIMA overcomes the invalidation problem of the state-of-the-art algorithms based on affine geometry features, and increases the feature diversity of different targets, thus reducing misjudgment rate during recognizing targets. However, it is found that FIMA suffers from the parallelogram contour problem and the coincidence invalidation. An advanced FIMA is designed to cope with these problems. Experiments prove that the proposed algorithms have better robustness for Gaussian noise, gray-scale change, contrast change, illumination and small three-dimensional rotation. Compared with the latest fast image matching algorithms based on geometry features, FIMA reaches the speedup of approximate 1.75 times. Thus, FIMA would be more suitable for actual ATR applications.展开更多
Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to th...Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to the loss of equipments and qualified persons. Indirect damages can lead to inflation and loss of purchasing power. To deal with that situation, parameters that govern the vulnerability of building construction site have been identified. Using a MCDM （multiple criteria decision making） method, the priority order of these parameters has been set. Then a PVI （partial vulnerability index） and a GVI （global vulnerability index） are proposed. These indexes allow the classification of building construction sites according to their intrinsic vulnerability and seismic vulnerability respectively that is through the use of a given classification. Several Algerian building construction sites belonging to different seismic zones were considered in order to show the applicability of the method.展开更多
Aiming at the interferometric inverse synthetic aperture radar （InlSAR） imaging in the presence of squint, we investigate the influence of squint on the InlSAR imaging. First, coupling of the squint additive phase a...Aiming at the interferometric inverse synthetic aperture radar （InlSAR） imaging in the presence of squint, we investigate the influence of squint on the InlSAR imaging. First, coupling of the squint additive phase and the target azimuth/altitude coordinates to be solved may make the solution more difficult. Second, the squint angle may lead to estimation error of the vertical coordinates and distortion of the ultimate image. Traditional InlSAR imaging algorithms can not solve the above two problems effectively, so we propose a new method which combines the nonlinear least square （NLS） and coordinates transform （CT） to estimate the target coordinates, and a three-dimensional （3-D） image consistent with the real target is obtained accordingly. Simulations show that the proposed method is effective for the squint-mode InlSAR imaging.展开更多
The displacement operator is an important and still a hot topic in map generalization. In the generalization product, symbols must be unambiguous and easily perceived and readily understood, which makes space competit...The displacement operator is an important and still a hot topic in map generalization. In the generalization product, symbols must be unambiguous and easily perceived and readily understood, which makes space competition among features an important obstacle in the process of map objects displacement. Space conflict between objects, through propagation process, may be spread and more objects may drift into it. In order to maintain symbols equilibrium and spatial relationship between objects, some unimportant symbols or parts of symbols should be distorted under constraints according to visual graphic resolution thresholds to figure out space competition among map features. Three constraints including position, legibility and characteristics are important for the maintenance of symbols equilibrium and spatial relationship, which are discussed in this paper. The skeleton is introduced to represent area objects figure characteristic, in which an area object can be separated to parts hierarchically according to their importance in the construction. Then, the finite element method is applied to the map objects’ displacement and distortion, in which a strategy for the parameters of finite element method is discussed.展开更多
文摘Infrared small target detection is a common task in infrared image processing.Under limited computa⁃tional resources.Traditional methods for infrared small target detection face a trade-off between the detection rate and the accuracy.A fast infrared small target detection method tailored for resource-constrained conditions is pro⁃posed for the YOLOv5s model.This method introduces an additional small target detection head and replaces the original Intersection over Union(IoU)metric with Normalized Wasserstein Distance(NWD),while considering both the detection accuracy and the detection speed of infrared small targets.Experimental results demonstrate that the proposed algorithm achieves a maximum effective detection speed of 95 FPS on a 15 W TPU,while reach⁃ing a maximum effective detection accuracy of 91.9 AP@0.5,effectively improving the efficiency of infrared small target detection under resource-constrained conditions.
文摘Most collision detection algorithms can be efficiently used only with solid and rigid objects, for instance, Hierarchical methods which must have their bounding representation recalculated every time deformation occurs. An alternative algorithm using particle-based method is then proposed which can detect the collision among non-rigid deformable polygonal models. However, the original particle-based collision detection algorithm might not be sufficient enough in some situations due to the improper particle dispersion. Therefore, this research presents an improved algorithm which provides a particle to detect in each separated area so that particles always covered all over the object. The surface partitioning can be efficiently performed by using LBG quantization since it can classify object vertices into several groups base on a number of factors as required. A particle is then assigned to move between vertices in a group by the attractive forces received from other particles on neighbouring objects. Collision is detected when the distance between a pair of corresponding particles becomes very small. Lastly, the proposed algo- rithm has been implemented to show that collision detection can be conducted in real-time.
基金Supported by the National Natural Science Foundation of China (No. 60772154)the President Foundation of Graduate University of Chinese Academy of Sciences (No. 085102GN00)
文摘Tracking multiple maneuvering targets remains a challenge due to the existence of clutter and the disturbance of spurious targets. Traditional tracking algorithms treat target measurements as points which results in the loss of information. We have propose a Signature Driven multiple-target Tracking (SDT) method which uses target signature in spectral,spatial and temporary spaces as well as the Markov property of target motion,and the data association process in SDT is very effective. The experimental results have shown its outstanding performance.
基金supported by National Natural Science Foundation of China (Grant No.40671007) Major Projects of Knowledge In-novation Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW-421)
文摘Aiming at alleviating the serious soil erosion, the Chinese government initiated the Sloping Land Conversion Program （SLCP） in 1999. Now; after 8 years of project implementation, the ecological recovery effects of the SLCP have become the hot issue of academic circle. This paper; raking the loess hill and gully area of northern Shaanxi as an example, presents a methodology for assessing the vegetation restoration effect of SLCP with normalized difference vegetation index （NDVI）. The key components include calculation of the Growing Season NDVI （GSNDVI）, and estimation of the NVDI change induced by climate and SLCP, respectively. Based on the method, the NDVI change between 2000 and 2006 was obtained using the GSNDVI that excluded the noise from snow and ice. After the part of total NDVI change caused to： climate variation was estimated using empiric formulae, we obtained the part induced by human factors, i.e. the SLCP The human induced part of ND VI change was considered as an approximation indicating the effect of the SLCP on the vegetation. Finally, we analyzed the ND VI change characters of the whole study area, different slope lands and different land use types by spatial statistics method. Results show that the vegetation condition is significantly improved by the SLCP, particularly land types that directly involved in the SLCP, such as steeply slope farmlands, degraded grasslands, etc.
基金Under the auspices of National Natural Science Foundation of China(No.41130748,41471143)
文摘The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.
文摘AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion （THD） and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.
基金Projects(2012AA010901,2012AA01A301)supported by National High Technology Research and Development Program of ChinaProjects(61272142,61103082,61003075,61170261,61103193)supported by the National Natural Science Foundation of ChinaProjects(B120601,CX2012A002)supported by Fund Sponsor Project of Excellent Postgraduate Student of NUDT,China
文摘Feature-based image matching algorithms play an indispensable role in automatic target recognition （ATR）. In this work, a fast image matching algorithm （FIMA） is proposed which utilizes the geometry feature of extended centroid （EC） to build affine invariants. Based on at-fine invariants of the length ratio of two parallel line segments, FIMA overcomes the invalidation problem of the state-of-the-art algorithms based on affine geometry features, and increases the feature diversity of different targets, thus reducing misjudgment rate during recognizing targets. However, it is found that FIMA suffers from the parallelogram contour problem and the coincidence invalidation. An advanced FIMA is designed to cope with these problems. Experiments prove that the proposed algorithms have better robustness for Gaussian noise, gray-scale change, contrast change, illumination and small three-dimensional rotation. Compared with the latest fast image matching algorithms based on geometry features, FIMA reaches the speedup of approximate 1.75 times. Thus, FIMA would be more suitable for actual ATR applications.
文摘Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to the loss of equipments and qualified persons. Indirect damages can lead to inflation and loss of purchasing power. To deal with that situation, parameters that govern the vulnerability of building construction site have been identified. Using a MCDM （multiple criteria decision making） method, the priority order of these parameters has been set. Then a PVI （partial vulnerability index） and a GVI （global vulnerability index） are proposed. These indexes allow the classification of building construction sites according to their intrinsic vulnerability and seismic vulnerability respectively that is through the use of a given classification. Several Algerian building construction sites belonging to different seismic zones were considered in order to show the applicability of the method.
基金supported by the China National Funds for Distinguished Young Scientists (Grant No.61025006)
文摘Aiming at the interferometric inverse synthetic aperture radar （InlSAR） imaging in the presence of squint, we investigate the influence of squint on the InlSAR imaging. First, coupling of the squint additive phase and the target azimuth/altitude coordinates to be solved may make the solution more difficult. Second, the squint angle may lead to estimation error of the vertical coordinates and distortion of the ultimate image. Traditional InlSAR imaging algorithms can not solve the above two problems effectively, so we propose a new method which combines the nonlinear least square （NLS） and coordinates transform （CT） to estimate the target coordinates, and a three-dimensional （3-D） image consistent with the real target is obtained accordingly. Simulations show that the proposed method is effective for the squint-mode InlSAR imaging.
基金Supported by the National Science Foundation of China (No40401050)the Leading Academic Discipline Project of Shanghai Educational Committee(NoJ50104)the Science Foundation of Shanghai Education Department (07ZZ09)
文摘The displacement operator is an important and still a hot topic in map generalization. In the generalization product, symbols must be unambiguous and easily perceived and readily understood, which makes space competition among features an important obstacle in the process of map objects displacement. Space conflict between objects, through propagation process, may be spread and more objects may drift into it. In order to maintain symbols equilibrium and spatial relationship between objects, some unimportant symbols or parts of symbols should be distorted under constraints according to visual graphic resolution thresholds to figure out space competition among map features. Three constraints including position, legibility and characteristics are important for the maintenance of symbols equilibrium and spatial relationship, which are discussed in this paper. The skeleton is introduced to represent area objects figure characteristic, in which an area object can be separated to parts hierarchically according to their importance in the construction. Then, the finite element method is applied to the map objects’ displacement and distortion, in which a strategy for the parameters of finite element method is discussed.
