Seizure detection is extremely essential for long-term monitoring of epileptic patients. This paper investigates the detection of epileptic seizures in multi-channel long-term intracranial electroencephalogram （iEEG...Seizure detection is extremely essential for long-term monitoring of epileptic patients. This paper investigates the detection of epileptic seizures in multi-channel long-term intracranial electroencephalogram （iEEG）. The algorithm conducts wavelet decomposition of iEEGs with five scales, and transforms the sum of the three frequency bands into histogram for computing the distance. The proposed method combines a novel feature called EMD-L1, which is an efficient algorithm of earth movers＇ distance （EMD）, with support vector machine （SVM） for binary classification between seizures and non-sei- zures. The EMD-LI used in this method is characterized by low time complexity and high processing speed by exploiting the L~ metric structure. The smoothing and collar technique are applied on the raw outputs of SVM classifier to obtain more ac- curate results. Several evaluation criteria are recommended to compare our algorithm with other conventional methods using the same dataset from the Freiburg EEG database. Experiment results show that the proposed method achieves a high sensi- tivity, specificity and low false detection rate, which are 95.73 %, 98.45 % and 0.33/h, respectively. This algorithm is char- acterized by its robustness and high accuracy with the possibility of performing real-time analysis of EEG data, and may serve as a seizure detection tool for monitoring long-term EEG.展开更多
A tubular moving-magnet linear oscillating motor（TMMLOM） has merits of high efficiency and excellent dynamic capability. To enhance the thrust performance, quasi-Halbach permanent magnet（PM） arrays are arranged on...A tubular moving-magnet linear oscillating motor（TMMLOM） has merits of high efficiency and excellent dynamic capability. To enhance the thrust performance, quasi-Halbach permanent magnet（PM） arrays are arranged on its mover in the application of a linear electro-hydrostatic actuator in more electric aircraft. The arrays are assembled by several individual segments, which lead to gaps between them inevitably. To investigate the effects of the gaps on the radial magnetic flux density and the machine thrust in this paper, an analytical model is built considering both axial and radial gaps. The model is validated by finite element simulations and experimental results.Distributions of the magnetic flux are described in condition of different sizes of radial and axial gaps. Besides, the output force is also discussed in normal and end windings. Finally, the model has demonstrated that both kinds of gaps have a negative effect on the thrust, and the linear motor is more sensitive to radial ones.展开更多
The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.The...The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.There are three types of slow-mover in urban waterfront space namely walking,stop or stay,and riding.Analysis of their behavioral characteristics and the difference of different people can help to clarify the design requirements and produce a waterfront space that will better meets people’s functional needs.展开更多
Purpose Design the sextupole precision mover for the Southern Advanced Photon Source that has requirements exceeding commercially available machines.Methods The design of the mover has been verified to meet the requir...Purpose Design the sextupole precision mover for the Southern Advanced Photon Source that has requirements exceeding commercially available machines.Methods The design of the mover has been verified to meet the requirements through a combination of static and dynamic simulations using ANSYS software,as well as relevant experimental testing.Results The mover we constructed has an absolute positioning error of 2 and 3µm,a maximum inclination angle of 1.55″and 5.67″in the horizontal and vertical motion directions respectively under a 400 kg load.Its vibration force transmission rate is 1.065.Conclusion The mover utilizes a non-coupled structure consisting of four layers of stainless steel plates,which exhibits good manufacturability.It is capable of achieving high precision and stability under a 400 kg load,meeting the requirements.展开更多
Perceptual quality assessment for point cloud is critical for immersive metaverse experience and is a challenging task.Firstly,because point cloud is formed by unstructured 3D points that makes the topology more compl...Perceptual quality assessment for point cloud is critical for immersive metaverse experience and is a challenging task.Firstly,because point cloud is formed by unstructured 3D points that makes the topology more complex.Secondly,the quality impairment generally involves both geometric attributes and color properties,where the measurement of the geometric distortion becomes more complex.We propose a perceptual point cloud quality assessment model that follows the perceptual features of Human Visual System(HVS)and the intrinsic characteristics of the point cloud.The point cloud is first pre-processed to extract the geometric skeleton keypoints with graph filtering-based re-sampling,and local neighboring regions around the geometric skeleton keypoints are constructed by K-Nearest Neighbors(KNN)clustering.For geometric distortion,the Point Feature Histogram(PFH)is extracted as the feature descriptor,and the Earth Mover’s Distance(EMD)between the PFHs of the corresponding local neighboring regions in the reference and the distorted point clouds is calculated as the geometric quality measurement.For color distortion,the statistical moments between the corresponding local neighboring regions are computed as the color quality measurement.Finally,the global perceptual quality assessment model is obtained as the linear weighting aggregation of the geometric and color quality measurement.The experimental results on extensive datasets show that the proposed method achieves the leading performance as compared to the state-of-the-art methods with less computing time.Meanwhile,the experimental results also demonstrate the robustness of the proposed method across various distortion types.The source codes are available at https://github.com/llsurreal919/Point Cloud Quality Assessment.展开更多
Background Sextupoles in the storage ring of HEPS will be adjusted based on beam trajectory.The mechanical design of a beam-based alignment sextupole mover should be developed.The motion accuracy of the mover should b...Background Sextupoles in the storage ring of HEPS will be adjusted based on beam trajectory.The mechanical design of a beam-based alignment sextupole mover should be developed.The motion accuracy of the mover should be better than 5µm under 450 kg load of sextupoles.The movement range is required to be±0.3 mm in both horizontal direction and vertical direction.And the first-order natural frequency of the magnet support system which include movers should be higher than 54 Hz.Purpose The purpose of this paper is to design a mover prototype and to realize its movement performance and equivalent stiffness.And to find the difficulties of development of this mover.Method Interferometer is used to measure the motion accuracy,and pressure accelerometer is used to test the mover equivalent stiffness.Combining with the actual measurement results of equivalent stiffness,the natural frequency of the magnet support system is simulated.Result The motion accuracy reaches to 5.3µm in vertical direction and 1µm in horizontal direction,respectively.The equivalent stiffness of the mover prototype can just able to meet the requirement of frequency of the HEPS magnet support system.Unwanted movement coupling has occurred during the mover exercises in vertical direction.Conclusions Through the research of experimental mover prototype,the methods have been learnt to improve the movement performance and equivalent stiffness of the mover based on sliding friction under high load.However,further researches and improvements are necessary to fix the coupling error during the vertical movement.展开更多
Color descriptors are one of the important features used in content-based in, age retrieval. The dominant color descriptor （DCD） represents a few perceptually dominant colors in an image through color quantization. ...Color descriptors are one of the important features used in content-based in, age retrieval. The dominant color descriptor （DCD） represents a few perceptually dominant colors in an image through color quantization. For image retrieval based on DCD, the earth mover＇s distance （EMD） and the optimal color composition distance were proposed to measure the dissimilarity between two images. Although providing good retrieval results, both methods are too time-consuming to be used in a large image database. To solve the problem, we propose a new distance function that calculates an approximate earth mover＇s distance in linear time. To calculate the dissimilarity in linear time, the proposed approach employs the space-filling curve for multidimensional color space. To improve the accuracy, the proposed approach uses multiple curves and adjusts the color positions. As a result, our approach achieves order-of-magnitude time improvement but incurs small errors. We have performed extensive experiments to show the effectiveness and efficiency of the proposed approach. The results reveal that our approach achieves almost the same results with the EMD in linear time.展开更多
In keeping with a view that is explicitly formulated by Aristotle in his Motion of Animals, general kinetic principles must be specified according to the different types of movable entities existing in the universe. A...In keeping with a view that is explicitly formulated by Aristotle in his Motion of Animals, general kinetic principles must be specified according to the different types of movable entities existing in the universe. At issue, essentially, are the motions of the stars and the motions of animals. Whereas the cosmological immovable mover is the object of two complementary analyses （in Bk. Ⅷ of Physics and in Chs. 6 and 7 of Bk. Ⅻ of Metaphysics）, information on the immovability of the first mover responsible for animal motion is to be found in the psychological and psycho-physiological treatises （On the Soul, in Bk. Ⅰ, Chs. 3 and 4, and in Bk. Ⅲ, Ch. 10 and in Ch. 6 of the Motion of Animals）. But it is also found in Ch. 7, Bk. Ⅻ of the Metaphysics, in the very context of the argument concerning the absolutely first immovable mover of the world. This suggests that the two types of motion, that of the stars and that of animals, however distinct the arguments about them are, rest on a single scheme, and maybe even on a common principle. This is liable to surprise us, as much as stars and animals appear to us to belong to heterogeneous orders of reality. But the situation is different for Aristotle, who, as attentive as he is to differences, tends nonetheless to conceive the stars as living things of a particular kind. This fact is the source of a series of difficulties that Aristotle generously left for his many commentators to solve. Aim of this text, which was initially directed to a larger audience, is to set some of these complex issues in both simple and up to date terms.展开更多
In an exhibition area of the World Economic Forum's (WEF) Annual Meeti ng of the New Cham pions in China's northeastern coastal city of Dalian, a robot was performing a surgical operation on a rose. The volunt...In an exhibition area of the World Economic Forum's (WEF) Annual Meeti ng of the New Cham pions in China's northeastern coastal city of Dalian, a robot was performing a surgical operation on a rose. The volunteers in the booth invited visitors to have a go at running the machine, which was developed by U.S. company Intuitive Surgical and has been used in 6 million successful surgeries worldwide. Over 110,000 of these were done in China, which has around 80 such robots in use in hospitals.展开更多
基金Key Program of Natural Science Foundation of Shandong Province(No.ZR2013FZ002)Program of Science and Technology of Suzhou(No.ZXY2013030)Independent Innovation Foundation of Shandong University(No.2012DX008)
文摘Seizure detection is extremely essential for long-term monitoring of epileptic patients. This paper investigates the detection of epileptic seizures in multi-channel long-term intracranial electroencephalogram （iEEG）. The algorithm conducts wavelet decomposition of iEEGs with five scales, and transforms the sum of the three frequency bands into histogram for computing the distance. The proposed method combines a novel feature called EMD-L1, which is an efficient algorithm of earth movers＇ distance （EMD）, with support vector machine （SVM） for binary classification between seizures and non-sei- zures. The EMD-LI used in this method is characterized by low time complexity and high processing speed by exploiting the L~ metric structure. The smoothing and collar technique are applied on the raw outputs of SVM classifier to obtain more ac- curate results. Several evaluation criteria are recommended to compare our algorithm with other conventional methods using the same dataset from the Freiburg EEG database. Experiment results show that the proposed method achieves a high sensi- tivity, specificity and low false detection rate, which are 95.73 %, 98.45 % and 0.33/h, respectively. This algorithm is char- acterized by its robustness and high accuracy with the possibility of performing real-time analysis of EEG data, and may serve as a seizure detection tool for monitoring long-term EEG.
基金supports of National Basic Research Program of China(973 Program)(No.2014CB046402)National Natural Science Foundation of China(Nos.51620105010,51575019,51675019,51505015)111 Program of China
文摘A tubular moving-magnet linear oscillating motor（TMMLOM） has merits of high efficiency and excellent dynamic capability. To enhance the thrust performance, quasi-Halbach permanent magnet（PM） arrays are arranged on its mover in the application of a linear electro-hydrostatic actuator in more electric aircraft. The arrays are assembled by several individual segments, which lead to gaps between them inevitably. To investigate the effects of the gaps on the radial magnetic flux density and the machine thrust in this paper, an analytical model is built considering both axial and radial gaps. The model is validated by finite element simulations and experimental results.Distributions of the magnetic flux are described in condition of different sizes of radial and axial gaps. Besides, the output force is also discussed in normal and end windings. Finally, the model has demonstrated that both kinds of gaps have a negative effect on the thrust, and the linear motor is more sensitive to radial ones.
基金supported by the Ministry of Education Humanities and Social Sciences Research Project(Grant No.19YJC760024).
文摘The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.There are three types of slow-mover in urban waterfront space namely walking,stop or stay,and riding.Analysis of their behavioral characteristics and the difference of different people can help to clarify the design requirements and produce a waterfront space that will better meets people’s functional needs.
文摘Purpose Design the sextupole precision mover for the Southern Advanced Photon Source that has requirements exceeding commercially available machines.Methods The design of the mover has been verified to meet the requirements through a combination of static and dynamic simulations using ANSYS software,as well as relevant experimental testing.Results The mover we constructed has an absolute positioning error of 2 and 3µm,a maximum inclination angle of 1.55″and 5.67″in the horizontal and vertical motion directions respectively under a 400 kg load.Its vibration force transmission rate is 1.065.Conclusion The mover utilizes a non-coupled structure consisting of four layers of stainless steel plates,which exhibits good manufacturability.It is capable of achieving high precision and stability under a 400 kg load,meeting the requirements.
基金supported in part by the National Natural Science Foundation of China under Grant(62171257,U22B2001,U19A2052,62020106011,62061015)in part by the Natural Science Foundation of Chongqing under Grant(2023NSCQMSX2930)+1 种基金in part by the Youth Innovation Group Support Program of ICE Discipline of CQUPT under Grant(SCIE-QN-2022-05)in part by the Graduate Scientifc Research and Innovation Project of Chongqing under Grant(CYS22469).
文摘Perceptual quality assessment for point cloud is critical for immersive metaverse experience and is a challenging task.Firstly,because point cloud is formed by unstructured 3D points that makes the topology more complex.Secondly,the quality impairment generally involves both geometric attributes and color properties,where the measurement of the geometric distortion becomes more complex.We propose a perceptual point cloud quality assessment model that follows the perceptual features of Human Visual System(HVS)and the intrinsic characteristics of the point cloud.The point cloud is first pre-processed to extract the geometric skeleton keypoints with graph filtering-based re-sampling,and local neighboring regions around the geometric skeleton keypoints are constructed by K-Nearest Neighbors(KNN)clustering.For geometric distortion,the Point Feature Histogram(PFH)is extracted as the feature descriptor,and the Earth Mover’s Distance(EMD)between the PFHs of the corresponding local neighboring regions in the reference and the distorted point clouds is calculated as the geometric quality measurement.For color distortion,the statistical moments between the corresponding local neighboring regions are computed as the color quality measurement.Finally,the global perceptual quality assessment model is obtained as the linear weighting aggregation of the geometric and color quality measurement.The experimental results on extensive datasets show that the proposed method achieves the leading performance as compared to the state-of-the-art methods with less computing time.Meanwhile,the experimental results also demonstrate the robustness of the proposed method across various distortion types.The source codes are available at https://github.com/llsurreal919/Point Cloud Quality Assessment.
文摘Background Sextupoles in the storage ring of HEPS will be adjusted based on beam trajectory.The mechanical design of a beam-based alignment sextupole mover should be developed.The motion accuracy of the mover should be better than 5µm under 450 kg load of sextupoles.The movement range is required to be±0.3 mm in both horizontal direction and vertical direction.And the first-order natural frequency of the magnet support system which include movers should be higher than 54 Hz.Purpose The purpose of this paper is to design a mover prototype and to realize its movement performance and equivalent stiffness.And to find the difficulties of development of this mover.Method Interferometer is used to measure the motion accuracy,and pressure accelerometer is used to test the mover equivalent stiffness.Combining with the actual measurement results of equivalent stiffness,the natural frequency of the magnet support system is simulated.Result The motion accuracy reaches to 5.3µm in vertical direction and 1µm in horizontal direction,respectively.The equivalent stiffness of the mover prototype can just able to meet the requirement of frequency of the HEPS magnet support system.Unwanted movement coupling has occurred during the mover exercises in vertical direction.Conclusions Through the research of experimental mover prototype,the methods have been learnt to improve the movement performance and equivalent stiffness of the mover based on sliding friction under high load.However,further researches and improvements are necessary to fix the coupling error during the vertical movement.
基金supported by the MSIP(Ministry of Science,ICT,and Future Planning),Korea,under the IT-CRSP(IT Convergence Research Support Program)with No.NIPA-2013-H0401-13-1001 supervised by the NIPA(National IT Industry Promotion Agency)the NRF(National Research Foundation)of Korea Grant funded by the Korean Government with No.NRF-2011-330-B00076supported by the Basic Science Research Program through the NRF funded by the Ministry of Education,Science and Technology of Korea under Grant Nos.2012R1A1A2007817 and 2013R1A6A3A03027153
文摘Color descriptors are one of the important features used in content-based in, age retrieval. The dominant color descriptor （DCD） represents a few perceptually dominant colors in an image through color quantization. For image retrieval based on DCD, the earth mover＇s distance （EMD） and the optimal color composition distance were proposed to measure the dissimilarity between two images. Although providing good retrieval results, both methods are too time-consuming to be used in a large image database. To solve the problem, we propose a new distance function that calculates an approximate earth mover＇s distance in linear time. To calculate the dissimilarity in linear time, the proposed approach employs the space-filling curve for multidimensional color space. To improve the accuracy, the proposed approach uses multiple curves and adjusts the color positions. As a result, our approach achieves order-of-magnitude time improvement but incurs small errors. We have performed extensive experiments to show the effectiveness and efficiency of the proposed approach. The results reveal that our approach achieves almost the same results with the EMD in linear time.
文摘In keeping with a view that is explicitly formulated by Aristotle in his Motion of Animals, general kinetic principles must be specified according to the different types of movable entities existing in the universe. At issue, essentially, are the motions of the stars and the motions of animals. Whereas the cosmological immovable mover is the object of two complementary analyses （in Bk. Ⅷ of Physics and in Chs. 6 and 7 of Bk. Ⅻ of Metaphysics）, information on the immovability of the first mover responsible for animal motion is to be found in the psychological and psycho-physiological treatises （On the Soul, in Bk. Ⅰ, Chs. 3 and 4, and in Bk. Ⅲ, Ch. 10 and in Ch. 6 of the Motion of Animals）. But it is also found in Ch. 7, Bk. Ⅻ of the Metaphysics, in the very context of the argument concerning the absolutely first immovable mover of the world. This suggests that the two types of motion, that of the stars and that of animals, however distinct the arguments about them are, rest on a single scheme, and maybe even on a common principle. This is liable to surprise us, as much as stars and animals appear to us to belong to heterogeneous orders of reality. But the situation is different for Aristotle, who, as attentive as he is to differences, tends nonetheless to conceive the stars as living things of a particular kind. This fact is the source of a series of difficulties that Aristotle generously left for his many commentators to solve. Aim of this text, which was initially directed to a larger audience, is to set some of these complex issues in both simple and up to date terms.
文摘In an exhibition area of the World Economic Forum's (WEF) Annual Meeti ng of the New Cham pions in China's northeastern coastal city of Dalian, a robot was performing a surgical operation on a rose. The volunteers in the booth invited visitors to have a go at running the machine, which was developed by U.S. company Intuitive Surgical and has been used in 6 million successful surgeries worldwide. Over 110,000 of these were done in China, which has around 80 such robots in use in hospitals.
