针对基于EMD(Earth Mover's Distance)的文档语义相似性算法不满足度量公理因而难以在信息检索与数据挖掘中推广应用的问题,该文提出了一种新的基于EMD的文档语义相似性度量——..Mdss_EMD(Metric for document semantic similarity...针对基于EMD(Earth Mover's Distance)的文档语义相似性算法不满足度量公理因而难以在信息检索与数据挖掘中推广应用的问题,该文提出了一种新的基于EMD的文档语义相似性度量——..Mdss_EMD(Metric for document semantic similarity based EMD)。首先在分析EMD及现有改进方法缺陷的基础上,给出了文档宽度、虚拟项的概念;随后通过增加虚拟项来对齐文档矢量的总权值,使所有度量公理得到满足;最后,为提高该度量的适应能力及处理速度,还实现了虚拟项相似距离的弹性设计并对EMD算法进行了简化。该方法把EMD扩展到度量空间中来,很大程度上提高了EMD的索引能力与精度,初步实验表明,Mdss_EMD的整体性能优于原EMD及现有其它类似方法。展开更多
风险价值(value at risk,VaR)是国际金融界广泛支持和认可的一种度量金融风险的工具。分别利用Bootstrap、MOVER(method of variance estimates recovery)和Fiducial方法给出正态总体下VaR的区间估计方法,并进行了模拟比较。模拟结果发...风险价值(value at risk,VaR)是国际金融界广泛支持和认可的一种度量金融风险的工具。分别利用Bootstrap、MOVER(method of variance estimates recovery)和Fiducial方法给出正态总体下VaR的区间估计方法,并进行了模拟比较。模拟结果发现基于Fiducial思想的广义区间估计在覆盖率和区间等尾性上具有更稳健的性质。最后对上证180重点指数的对数收益率VaR进行了分析。展开更多
Based on the Cockroach Swarm Optimization （CSO） algorithm, a new Cockroach Colony Optimization （CCO） algorithm is presented and applied to the Robot Path Planning （RPP） problem in this paper. In the CCO algorith...Based on the Cockroach Swarm Optimization （CSO） algorithm, a new Cockroach Colony Optimization （CCO） algorithm is presented and applied to the Robot Path Planning （RPP） problem in this paper. In the CCO algorithm, an improved grid map is used for environment modeling, and 16-geometry and 8-geometry are introduced, respectively, in food division and cockroach search operation. Moreover, the CCO algorithm adopts a non-probabilistic search strategy, which avoids a lot of invalid searches. Furthermore, by introducing a novel rotation scheme in the above CCO algorithm, an Adaptive Cockroach Colony Optimization （ACCO） algorithm is presented for the 2-D Rod-Like Robot Path Planning （RLRPP） problem. The simulation results show that the CCO algorithm can plan an optimal or approximately optimal collision-free path with linear time com- plexities. With the ACCO algorithm, the robot can accomplish intelligent and adaptive rotations to avoid obstacles and pass through narrow passages along the better path.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
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 number of mobile application services is showing an explosive growth trend,which makes it difficult for users to determine which ones are of interest.Especially,the new mobile application services are emerge conti...The number of mobile application services is showing an explosive growth trend,which makes it difficult for users to determine which ones are of interest.Especially,the new mobile application services are emerge continuously,most of them have not be rated when they need to be recommended to users.This is the typical problem of cold start in the field of collaborative filtering recommendation.This problem may makes it difficult for users to locate and acquire the services that they actually want,and the accuracy and novelty of service recommendations are also difficult to satisfy users.To solve this problem,a hybrid recommendation method for mobile application services based on content feature extraction is proposed in this paper.First,the proposed method in this paper extracts service content features through Natural Language Processing technologies such as word segmentation,part-of-speech tagging,and dependency parsing.It improves the accuracy of describing service attributes and the rationality of the method of calculating service similarity.Then,a language representation model called Bidirectional Encoder Representation from Transformers(BERT)is used to vectorize the content feature text,and an improved weighted word mover’s distance algorithm based on Term Frequency-Inverse Document Frequency(TFIDF-WMD)is used to calculate the similarity of mobile application services.Finally,the recommendation process is completed by combining the item-based collaborative filtering recommendation algorithm.The experimental results show that by using the proposed hybrid recommendation method presented in this paper,the cold start problem is alleviated to a certain extent,and the accuracy of the recommendation result has been significantly improved.展开更多
The technique of image retrieval is widely used in science experiment, military affairs, public security, advertisement, family entertainment, library and so on. The existing algorithms are mostly based on the charact...The technique of image retrieval is widely used in science experiment, military affairs, public security, advertisement, family entertainment, library and so on. The existing algorithms are mostly based on the characteristics of color, texture, shape and space relationship. This paper introduced an image retrieval algorithm, which is based on the matching of weighted EMD（Earth Mover’s Distance） distance and texture distance. EMD distance is the distance between the histograms of two images in HSV（Hue, Saturation, Value） color space, and texture distance is the L1 distance between the texture spectra of two images. The experimental results show that the retrieval rate can be increased obviously by using the proposed algorithm.展开更多
It is argued in this paper that the famous ＂Active Intellect＂ of De Anima 3.5 is not God, as Alexander of Aphrodisias held, but rather an unchanging, eternally cognizing Intellect which serves as the indispensable c...It is argued in this paper that the famous ＂Active Intellect＂ of De Anima 3.5 is not God, as Alexander of Aphrodisias held, but rather an unchanging, eternally cognizing Intellect which serves as the indispensable condition for the operation of human intellect. It is ＂at the door＂ for each individual, ready to flow in as a stream of light--a light which renders potential objects of cognition knowable, just as visible light makes potentially visible objects visible--from outside that door （thyrathen） any time it is opened. Its existence cannot serve, however, as a proof of the immortality of human intellect, since, being unchanging, it can never possess a feature of human intellect which is characterized by nothing if not change, and that is memory.展开更多
文摘针对基于EMD(Earth Mover's Distance)的文档语义相似性算法不满足度量公理因而难以在信息检索与数据挖掘中推广应用的问题,该文提出了一种新的基于EMD的文档语义相似性度量——..Mdss_EMD(Metric for document semantic similarity based EMD)。首先在分析EMD及现有改进方法缺陷的基础上,给出了文档宽度、虚拟项的概念;随后通过增加虚拟项来对齐文档矢量的总权值,使所有度量公理得到满足;最后,为提高该度量的适应能力及处理速度,还实现了虚拟项相似距离的弹性设计并对EMD算法进行了简化。该方法把EMD扩展到度量空间中来,很大程度上提高了EMD的索引能力与精度,初步实验表明,Mdss_EMD的整体性能优于原EMD及现有其它类似方法。
文摘风险价值(value at risk,VaR)是国际金融界广泛支持和认可的一种度量金融风险的工具。分别利用Bootstrap、MOVER(method of variance estimates recovery)和Fiducial方法给出正态总体下VaR的区间估计方法,并进行了模拟比较。模拟结果发现基于Fiducial思想的广义区间估计在覆盖率和区间等尾性上具有更稳健的性质。最后对上证180重点指数的对数收益率VaR进行了分析。
基金This work was supported by the Hong Kong Re- search Grant Council （project CityU123809）, the Na- tional Natural Science Foundation of China （Grant nos. 60571048, 60873264, 60971088 and 71301078）, the Qing Lan Project, the Natural Science Foundation of Education Bureau of Jiangsu Province （project 13KJB120006） and the Innovation Foundation of Huaian College of Information Technology （project hxyc2013001）.
文摘Based on the Cockroach Swarm Optimization （CSO） algorithm, a new Cockroach Colony Optimization （CCO） algorithm is presented and applied to the Robot Path Planning （RPP） problem in this paper. In the CCO algorithm, an improved grid map is used for environment modeling, and 16-geometry and 8-geometry are introduced, respectively, in food division and cockroach search operation. Moreover, the CCO algorithm adopts a non-probabilistic search strategy, which avoids a lot of invalid searches. Furthermore, by introducing a novel rotation scheme in the above CCO algorithm, an Adaptive Cockroach Colony Optimization （ACCO） algorithm is presented for the 2-D Rod-Like Robot Path Planning （RLRPP） problem. The simulation results show that the CCO algorithm can plan an optimal or approximately optimal collision-free path with linear time com- plexities. With the ACCO algorithm, the robot can accomplish intelligent and adaptive rotations to avoid obstacles and pass through narrow passages along the better path.
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.
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Project supported by the National Natural Science Foundation,China(No.62172123)the Postdoctoral Science Foundation of Heilongjiang Province,China(No.LBH-Z19067)+1 种基金the special projects for the central government to guide the development of local science and technology,China(No.ZY20B11)the Natural Science Foundation of Heilongjiang Province,China(No.QC2018081).
文摘The number of mobile application services is showing an explosive growth trend,which makes it difficult for users to determine which ones are of interest.Especially,the new mobile application services are emerge continuously,most of them have not be rated when they need to be recommended to users.This is the typical problem of cold start in the field of collaborative filtering recommendation.This problem may makes it difficult for users to locate and acquire the services that they actually want,and the accuracy and novelty of service recommendations are also difficult to satisfy users.To solve this problem,a hybrid recommendation method for mobile application services based on content feature extraction is proposed in this paper.First,the proposed method in this paper extracts service content features through Natural Language Processing technologies such as word segmentation,part-of-speech tagging,and dependency parsing.It improves the accuracy of describing service attributes and the rationality of the method of calculating service similarity.Then,a language representation model called Bidirectional Encoder Representation from Transformers(BERT)is used to vectorize the content feature text,and an improved weighted word mover’s distance algorithm based on Term Frequency-Inverse Document Frequency(TFIDF-WMD)is used to calculate the similarity of mobile application services.Finally,the recommendation process is completed by combining the item-based collaborative filtering recommendation algorithm.The experimental results show that by using the proposed hybrid recommendation method presented in this paper,the cold start problem is alleviated to a certain extent,and the accuracy of the recommendation result has been significantly improved.
文摘The technique of image retrieval is widely used in science experiment, military affairs, public security, advertisement, family entertainment, library and so on. The existing algorithms are mostly based on the characteristics of color, texture, shape and space relationship. This paper introduced an image retrieval algorithm, which is based on the matching of weighted EMD（Earth Mover’s Distance） distance and texture distance. EMD distance is the distance between the histograms of two images in HSV（Hue, Saturation, Value） color space, and texture distance is the L1 distance between the texture spectra of two images. The experimental results show that the retrieval rate can be increased obviously by using the proposed algorithm.
文摘It is argued in this paper that the famous ＂Active Intellect＂ of De Anima 3.5 is not God, as Alexander of Aphrodisias held, but rather an unchanging, eternally cognizing Intellect which serves as the indispensable condition for the operation of human intellect. It is ＂at the door＂ for each individual, ready to flow in as a stream of light--a light which renders potential objects of cognition knowable, just as visible light makes potentially visible objects visible--from outside that door （thyrathen） any time it is opened. Its existence cannot serve, however, as a proof of the immortality of human intellect, since, being unchanging, it can never possess a feature of human intellect which is characterized by nothing if not change, and that is memory.
