Obtaining a 3D feature description with high descriptiveness and robustness under complicated nuisances is a significant and challenging task in 3D feature matching.This paper proposes a novel feature description cons...Obtaining a 3D feature description with high descriptiveness and robustness under complicated nuisances is a significant and challenging task in 3D feature matching.This paper proposes a novel feature description consisting of a stable local reference frame(LRF)and a feature descriptor based on local spatial voxels.First,an improved LRF was designed by incorporating distance weights into Z-and X-axis calculations.Subsequently,based on the LRF and voxel segmentation,a feature descriptor based on voxel homogenization was proposed.Moreover,uniform segmentation of cube voxels was performed,considering the eigenvalues of each voxel and its neighboring voxels,thereby enhancing the stability of the description.The performance of the descriptor was strictly tested and evaluated on three public datasets,which exhibited high descriptiveness,robustness,and superior performance compared with other current methods.Furthermore,the descriptor was applied to a 3D registration trial,and the results demonstrated the reliability of our approach.展开更多
A fast local reference frame(LRF)construction method based on the signed surface variation is proposed,which can adapt to the real-time applications such as self-driving,face recognition,object detection.The z-axis of...A fast local reference frame(LRF)construction method based on the signed surface variation is proposed,which can adapt to the real-time applications such as self-driving,face recognition,object detection.The z-axis of the LRF is generated based on the concavity of the local surface of keypoint.The x-axis is constructed by the weighted vector sum of a set of projection vectors of the local neighborhoods around keypoint.The performance of the proposed LRF is evaluated on six standard datasets and compared with six state-of-the-art LRF construction methods(e.g.,BOARD,FLARE,SHOT,RoPS and TOLDI).Experimental results validate the high repeatability,robustness,universality and time efficiency of our method.展开更多
Community knowledge about agricultural land and its management constitutes a complex system of wisdom, with universal principles and categories similar or complementary to those used by modern soil science. However, s...Community knowledge about agricultural land and its management constitutes a complex system of wisdom, with universal principles and categories similar or complementary to those used by modern soil science. However, soil management is only recognized from the point of view of agronomy and academia, covering problems in rural areas at the time of adopting agricultural alternatives. For this reason, peasant knowledge was characterized and related to scientific knowledge, in the valuation of land properties in the coffee (Coffea arabica L.) production system. The study was carried out in four villages in the municipality of Buesaco (Nari?o, Colombia), with humid pre-mountain forest conditions, an average temperature of 18?C, annual rainfall of 1400 mm, and an altitude of 1959 m. The study was carried out in the municipality of Buesaco (Nari?o, Colombia). Through field visits, priority was given to farms with coffee production systems under different types of shade. A semi-structured survey was applied to learn about the social, environmental, productive, ancestral, and cultural components, with the application of participatory methodologies allowed to learn about traditional management and practices in the soil component. The results allowed us to identify four types of production systems from coffee without shade to coffee in association with different multipurpose woody perennials and mosses. Diverse dynamics of crop and land management are presented. Several references were found to differentiate land types such as color, texture, production and fertility, being characteristics that are associated to classify soil quality and make management decisions and type of fertilization. Through the perception of the farmers, six land classes with different characteristics were identified, relating the characterization with what was obtained in the chemical analysis of lands. It can be concluded that the perception of coffee growers, dark shades in the land representing better quality than light shaded soils, both associated with characteristics such as quantity of organic matter, presence of weeds, growth and development of the crop, perceptions that coincide with the variables of scientific knowledge such as availability of nutrients, organic matter, pH and texture.展开更多
Based on the characteristics of distrubuted system and the behavior of parallelprograms, this paper presents the fixed and randofored competitive memory coherence algorithms for distributed shared virtual memory These...Based on the characteristics of distrubuted system and the behavior of parallelprograms, this paper presents the fixed and randofored competitive memory coherence algorithms for distributed shared virtual memory These algorithms exploit parallel programs' locality of reference and dribit good competitive property Our simulation shows that the fixed and randomized algorithms achieve better performance and higher stability than other strategies such as write-invalldate and write-update.展开更多
基金the National Natural Science Foundation of China,No.51705469the Zhengzhou University Youth Talent Enterprise Cooperative Innovation Team Support Program Project(2021,2022).
文摘Obtaining a 3D feature description with high descriptiveness and robustness under complicated nuisances is a significant and challenging task in 3D feature matching.This paper proposes a novel feature description consisting of a stable local reference frame(LRF)and a feature descriptor based on local spatial voxels.First,an improved LRF was designed by incorporating distance weights into Z-and X-axis calculations.Subsequently,based on the LRF and voxel segmentation,a feature descriptor based on voxel homogenization was proposed.Moreover,uniform segmentation of cube voxels was performed,considering the eigenvalues of each voxel and its neighboring voxels,thereby enhancing the stability of the description.The performance of the descriptor was strictly tested and evaluated on three public datasets,which exhibited high descriptiveness,robustness,and superior performance compared with other current methods.Furthermore,the descriptor was applied to a 3D registration trial,and the results demonstrated the reliability of our approach.
基金Youth Program of National Natural Science Foundation of China(Nos.41901415,61801481)。
文摘A fast local reference frame(LRF)construction method based on the signed surface variation is proposed,which can adapt to the real-time applications such as self-driving,face recognition,object detection.The z-axis of the LRF is generated based on the concavity of the local surface of keypoint.The x-axis is constructed by the weighted vector sum of a set of projection vectors of the local neighborhoods around keypoint.The performance of the proposed LRF is evaluated on six standard datasets and compared with six state-of-the-art LRF construction methods(e.g.,BOARD,FLARE,SHOT,RoPS and TOLDI).Experimental results validate the high repeatability,robustness,universality and time efficiency of our method.
文摘Community knowledge about agricultural land and its management constitutes a complex system of wisdom, with universal principles and categories similar or complementary to those used by modern soil science. However, soil management is only recognized from the point of view of agronomy and academia, covering problems in rural areas at the time of adopting agricultural alternatives. For this reason, peasant knowledge was characterized and related to scientific knowledge, in the valuation of land properties in the coffee (Coffea arabica L.) production system. The study was carried out in four villages in the municipality of Buesaco (Nari?o, Colombia), with humid pre-mountain forest conditions, an average temperature of 18?C, annual rainfall of 1400 mm, and an altitude of 1959 m. The study was carried out in the municipality of Buesaco (Nari?o, Colombia). Through field visits, priority was given to farms with coffee production systems under different types of shade. A semi-structured survey was applied to learn about the social, environmental, productive, ancestral, and cultural components, with the application of participatory methodologies allowed to learn about traditional management and practices in the soil component. The results allowed us to identify four types of production systems from coffee without shade to coffee in association with different multipurpose woody perennials and mosses. Diverse dynamics of crop and land management are presented. Several references were found to differentiate land types such as color, texture, production and fertility, being characteristics that are associated to classify soil quality and make management decisions and type of fertilization. Through the perception of the farmers, six land classes with different characteristics were identified, relating the characterization with what was obtained in the chemical analysis of lands. It can be concluded that the perception of coffee growers, dark shades in the land representing better quality than light shaded soils, both associated with characteristics such as quantity of organic matter, presence of weeds, growth and development of the crop, perceptions that coincide with the variables of scientific knowledge such as availability of nutrients, organic matter, pH and texture.
文摘Based on the characteristics of distrubuted system and the behavior of parallelprograms, this paper presents the fixed and randofored competitive memory coherence algorithms for distributed shared virtual memory These algorithms exploit parallel programs' locality of reference and dribit good competitive property Our simulation shows that the fixed and randomized algorithms achieve better performance and higher stability than other strategies such as write-invalldate and write-update.
