为了减小旋流器的短路流流量,提高旋流分离性能,研究提出了一种“喇叭型”溢流管旋流器,并通过数值模拟的方法,对不同尺寸“喇叭型”溢流管旋流器的压力场、速度场、湍流强度和分离效率进行了探讨。结果表明:随着“喇叭”长度的增加,静...为了减小旋流器的短路流流量,提高旋流分离性能,研究提出了一种“喇叭型”溢流管旋流器,并通过数值模拟的方法,对不同尺寸“喇叭型”溢流管旋流器的压力场、速度场、湍流强度和分离效率进行了探讨。结果表明:随着“喇叭”长度的增加,静压最大值从150.5 k Pa降低到139.7 k Pa,较低的静压可以减少能量消耗;“喇叭型”溢流管旋流器的轴向速度低于常规旋流器,颗粒在“喇叭型”溢流管旋流器内停留时间更长,分离更彻底;随着“喇叭”长度的增加,分流比和短路流流量都减小,降低了颗粒“错配”的数量;湍流强度随“喇叭”长度的增加而趋于平稳,使流场更加稳定;随着“喇叭”长度的增加,陡度指数先增大后减小,“喇叭”长度为20 mm时陡度指数最大,分离精度最高。展开更多
To analyze factors that affect the detection probability of six laser range-finders of rotating rocket,taking a missile as the target,the detection model was established according to a detection mechanism.Based on the...To analyze factors that affect the detection probability of six laser range-finders of rotating rocket,taking a missile as the target,the detection model was established according to a detection mechanism.Based on the model,the detection probability was calculated via Monte Carlo method under different conditions.With the calculation results,the relationship of detection probability with the rolling rate and the missile velocity was illustrated in figures,when the laser emitting frequency was 10 kHz,20 kHz,30 kHz respectively under the condition that rocket met the front of missile as well as the condition that rocket met the rear of missile.The figures show that the detection probability increases as laser emitting frequency increases or the rolling rate increases,while it decreases as the missile velocity increases.Detection probability is higher when rocket meets the front of missile than that when rocket meets the rear of missile.In order to maintain a track of approaching Mach 2 targets,rotation rate should be more than 100 r/s.展开更多
The Internet now is a large-scale platform with big data. Finding truth from a huge dataset has attracted extensive attention, which can maintain the quality of data collected by users and provide users with accurate ...The Internet now is a large-scale platform with big data. Finding truth from a huge dataset has attracted extensive attention, which can maintain the quality of data collected by users and provide users with accurate and efficient data. However, current truth finder algorithms are unsatisfying, because of their low accuracy and complication. This paper proposes a truth finder algorithm based on entity attributes (TFAEA). Based on the iterative computation of source reliability and fact accuracy, TFAEA considers the interactive degree among facts and the degree of dependence among sources, to simplify the typical truth finder algorithms. In order to improve the accuracy of them, TFAEA combines the one-way text similarity and the factual conflict to calculate the mutual support degree among facts. Furthermore, TFAEA utilizes the symmetric saturation of data sources to calculate the degree of dependence among sources. The experimental results show that TFAEA is not only more stable, but also more accurate than the typical truth finder algorithms.展开更多
Finger-tip range finders can be used to modify robot end effector's position & attitude and avoid collision. This paper introduces the development of finger tip short dis tance laser range finders for space ro...Finger-tip range finders can be used to modify robot end effector's position & attitude and avoid collision. This paper introduces the development of finger tip short dis tance laser range finders for space robot multisensory gripper, including the sensors' measuring principle, signal processing circuit, etc. By using these sensors' informations the gripper can be automatically ajusted to grasp the object steadily and reliablly even if it is badly positioned.展开更多
Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firs...Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firstly, 2D sequential laser range finder data were aligned using a Dead-Reckoning （DR） and GPS loeaHzation method based on extended Kalman filter. Secondly, curb points were extracted from multi.frame laser data based on spatial-temporal correlation analysis. Finally. the straight and curved curbs were detected by coordinate axis conversion least square linear fitting method and piecewise weighted least square fitting model respectively. The proposed method can detect both raised and sunken curbs robustly in campus environment. The proposed method has been verified in a real robot platform.展开更多
日前，巴斯夫全新的Pigment Finder（意为：颜料搜索）App上线，涂料、塑料和印刷等行业的颜料专业人士现在可以通过Pigment Finder App快速搜索最适合的颜料解决方案。这款App提供了关于颜料的概况信息．包括色度、色彩指数、化学成分...日前，巴斯夫全新的Pigment Finder（意为：颜料搜索）App上线，涂料、塑料和印刷等行业的颜料专业人士现在可以通过Pigment Finder App快速搜索最适合的颜料解决方案。这款App提供了关于颜料的概况信息．包括色度、色彩指数、化学成分以及关于主要功能和技术数据的详细信息。展开更多
文摘为了减小旋流器的短路流流量,提高旋流分离性能,研究提出了一种“喇叭型”溢流管旋流器,并通过数值模拟的方法,对不同尺寸“喇叭型”溢流管旋流器的压力场、速度场、湍流强度和分离效率进行了探讨。结果表明:随着“喇叭”长度的增加,静压最大值从150.5 k Pa降低到139.7 k Pa,较低的静压可以减少能量消耗;“喇叭型”溢流管旋流器的轴向速度低于常规旋流器,颗粒在“喇叭型”溢流管旋流器内停留时间更长,分离更彻底;随着“喇叭”长度的增加,分流比和短路流流量都减小,降低了颗粒“错配”的数量;湍流强度随“喇叭”长度的增加而趋于平稳,使流场更加稳定;随着“喇叭”长度的增加,陡度指数先增大后减小,“喇叭”长度为20 mm时陡度指数最大,分离精度最高。
文摘To analyze factors that affect the detection probability of six laser range-finders of rotating rocket,taking a missile as the target,the detection model was established according to a detection mechanism.Based on the model,the detection probability was calculated via Monte Carlo method under different conditions.With the calculation results,the relationship of detection probability with the rolling rate and the missile velocity was illustrated in figures,when the laser emitting frequency was 10 kHz,20 kHz,30 kHz respectively under the condition that rocket met the front of missile as well as the condition that rocket met the rear of missile.The figures show that the detection probability increases as laser emitting frequency increases or the rolling rate increases,while it decreases as the missile velocity increases.Detection probability is higher when rocket meets the front of missile than that when rocket meets the rear of missile.In order to maintain a track of approaching Mach 2 targets,rotation rate should be more than 100 r/s.
基金supported by the National Natural Science Foundation of China(61472192)the Scientific and Technological Support Project(Society)of Jiangsu Province(BE2016776)
文摘The Internet now is a large-scale platform with big data. Finding truth from a huge dataset has attracted extensive attention, which can maintain the quality of data collected by users and provide users with accurate and efficient data. However, current truth finder algorithms are unsatisfying, because of their low accuracy and complication. This paper proposes a truth finder algorithm based on entity attributes (TFAEA). Based on the iterative computation of source reliability and fact accuracy, TFAEA considers the interactive degree among facts and the degree of dependence among sources, to simplify the typical truth finder algorithms. In order to improve the accuracy of them, TFAEA combines the one-way text similarity and the factual conflict to calculate the mutual support degree among facts. Furthermore, TFAEA utilizes the symmetric saturation of data sources to calculate the degree of dependence among sources. The experimental results show that TFAEA is not only more stable, but also more accurate than the typical truth finder algorithms.
文摘Finger-tip range finders can be used to modify robot end effector's position & attitude and avoid collision. This paper introduces the development of finger tip short dis tance laser range finders for space robot multisensory gripper, including the sensors' measuring principle, signal processing circuit, etc. By using these sensors' informations the gripper can be automatically ajusted to grasp the object steadily and reliablly even if it is badly positioned.
基金National Natural Science Foundation of China(No.61603184)the Key Laboratory of Intelligent Perception and Systems for High-Dimensional Information(Nanjing University of Science and Technology),Ministry of Education,China(No.30920140122006)the Fundamental Research Funds for the Central Universities,China(No.30915011321)
文摘Curb detection is an important research topic in the unmanned ground robot. In this paper, a novel curb detection method using a 2D laser range fmder in an urban environment was presented. In the proposed method, firstly, 2D sequential laser range finder data were aligned using a Dead-Reckoning （DR） and GPS loeaHzation method based on extended Kalman filter. Secondly, curb points were extracted from multi.frame laser data based on spatial-temporal correlation analysis. Finally. the straight and curved curbs were detected by coordinate axis conversion least square linear fitting method and piecewise weighted least square fitting model respectively. The proposed method can detect both raised and sunken curbs robustly in campus environment. The proposed method has been verified in a real robot platform.
