This paper has been focused on investigating kinematics of Persian joint. In this study, instead of using the 3D （three dimensional） rotation matrix method as in the previous research, Persian joint is considered as...This paper has been focused on investigating kinematics of Persian joint. In this study, instead of using the 3D （three dimensional） rotation matrix method as in the previous research, Persian joint is considered as a robotic mechanism, and the methods and tools are applied to present the relationship of angular displacements of input shaft and output shaft. When the angle between intersecting shafts changes from 0 degree to 135 degrees, the results show that the velocities of input shaft and output shaft are almost the same with the actual values. This study provides a new method to investigate this mechanism in detail. The obtained results not only provide the sub-parameters （the displacement of guide arms and connecting arms）, but also help to have a deeper understanding about the operation of Persian joint in order to develop the design of Persian joint in the future.展开更多
A data-driven method was proposed to realistically animate garments on human poses in reduced space. Firstly, a gradient based method was extended to generate motion sequences and garments were simulated on the sequen...A data-driven method was proposed to realistically animate garments on human poses in reduced space. Firstly, a gradient based method was extended to generate motion sequences and garments were simulated on the sequences as our training data. Based on the examples, the proposed method can fast output realistic garments on new poses. Our framework can be mainly divided into offline phase and online phase. During the offline phase, based on linear blend skinning(LBS), rigid bones and flex bones were estimated for human bodies and garments, respectively. Then, rigid bone weight maps on garment vertices were learned from examples. In the online phase, new human poses were treated as input to estimate rigid bone transformations. Then, both rigid bones and flex bones were used to drive garments to fit the new poses. Finally, a novel formulation was also proposed to efficiently deal with garment-body penetration. Experiments manifest that our method is fast and accurate. The intersection artifacts are fast removed and final garment results are quite realistic.展开更多
In recent years studies of aquatic locomotion have provided some remarkable insights into the many features of fish swimming performances. This paper derives a scaling relation of aquatic locomotion CD(Re)~2 =(Sw)~2 a...In recent years studies of aquatic locomotion have provided some remarkable insights into the many features of fish swimming performances. This paper derives a scaling relation of aquatic locomotion CD(Re)~2 =(Sw)~2 and its corresponding log law and power law. For power scaling law,(Sw)~2 = β_nRe^((2-1)/n), which is valid within the full spectrum of the Reynolds number Re=UL/v from low up to high, can simply be expressed as the power law of the Reynolds number Re and the swimming number Sw=ωAL/v as Re ∝ (Sw)~σ,with σ=2 for creeping flows,σ=4/3 for laminar flows, σ=10/9 and σ=14/13 for turbulent flows. For log law this paper has derived the scaling law as Sw ∝ Re=(lnRe+1.287), which is even valid for a much wider range of the Reynolds number Re. Both power and log scaling relationships link the locomotory input variables that describe the swimmer's gait A;ω via the swimming number Sw to the locomotory output velocity U via the longitudinal Reynolds number Re, and reveal the secret input-output relationship of aquatic locomotion at different scales of the Reynolds number.展开更多
文摘This paper has been focused on investigating kinematics of Persian joint. In this study, instead of using the 3D （three dimensional） rotation matrix method as in the previous research, Persian joint is considered as a robotic mechanism, and the methods and tools are applied to present the relationship of angular displacements of input shaft and output shaft. When the angle between intersecting shafts changes from 0 degree to 135 degrees, the results show that the velocities of input shaft and output shaft are almost the same with the actual values. This study provides a new method to investigate this mechanism in detail. The obtained results not only provide the sub-parameters （the displacement of guide arms and connecting arms）, but also help to have a deeper understanding about the operation of Persian joint in order to develop the design of Persian joint in the future.
基金Project(20104307110003)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProjects(61379103,61202333,61303185)supported by the National Natural Science Foundation of China+1 种基金Project(2012M520392)supported by the China Postdoctoral Science FoundationProject(CX2012B027)supported by the Hunan Province Graduate Student Innovation Program,China
文摘A data-driven method was proposed to realistically animate garments on human poses in reduced space. Firstly, a gradient based method was extended to generate motion sequences and garments were simulated on the sequences as our training data. Based on the examples, the proposed method can fast output realistic garments on new poses. Our framework can be mainly divided into offline phase and online phase. During the offline phase, based on linear blend skinning(LBS), rigid bones and flex bones were estimated for human bodies and garments, respectively. Then, rigid bone weight maps on garment vertices were learned from examples. In the online phase, new human poses were treated as input to estimate rigid bone transformations. Then, both rigid bones and flex bones were used to drive garments to fit the new poses. Finally, a novel formulation was also proposed to efficiently deal with garment-body penetration. Experiments manifest that our method is fast and accurate. The intersection artifacts are fast removed and final garment results are quite realistic.
基金self-funded project:Similarity and Lie Group in Engineering Science
文摘In recent years studies of aquatic locomotion have provided some remarkable insights into the many features of fish swimming performances. This paper derives a scaling relation of aquatic locomotion CD(Re)~2 =(Sw)~2 and its corresponding log law and power law. For power scaling law,(Sw)~2 = β_nRe^((2-1)/n), which is valid within the full spectrum of the Reynolds number Re=UL/v from low up to high, can simply be expressed as the power law of the Reynolds number Re and the swimming number Sw=ωAL/v as Re ∝ (Sw)~σ,with σ=2 for creeping flows,σ=4/3 for laminar flows, σ=10/9 and σ=14/13 for turbulent flows. For log law this paper has derived the scaling law as Sw ∝ Re=(lnRe+1.287), which is even valid for a much wider range of the Reynolds number Re. Both power and log scaling relationships link the locomotory input variables that describe the swimmer's gait A;ω via the swimming number Sw to the locomotory output velocity U via the longitudinal Reynolds number Re, and reveal the secret input-output relationship of aquatic locomotion at different scales of the Reynolds number.
