The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and th...The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical展开更多
We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the b...We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the brake,even in strong winds.Experiments have shown that the triangularly coupled movable parallelogram buoyancy structure makes it easy to maintain the verticality of the wind turbine tower even under large waves.Furthermore,as a result of studying the connection between the HAWT(horizontal axis wind turbine)and the movable parallelogram buoyancy structure of the triangular connection,the feasibility was confirmed.The only way for all people in the world to secure energy and food fairly is to look for the remaining areas such as the high seas.The author would like to propose the use of the high seas to combat global hunger,which is likely to be a global problem in the future.展开更多
In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal eff...In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal effect on vibration of such plate has been taken as one-dimensional distribution in linear form only. An approximate but quiet convenient frequency equation is derived using Rayleigh-Ritz technique with a two-term deflection function. The frequencies corresponding to the first two modes of vibration of a clamped parallelogram plate have been computed for different values of aspect ratio, thermal gradient, taper constants and skew angle. The results have been presented in tabular forms. The results obtained in this study are reduced to that of unheated parallelogram plates of uniform thickness and have generally been compared with the published one.展开更多
Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</...Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.展开更多
Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthe...Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthesized and structurally characterized.Single-crystal X-ray diffraction analyses reveal that the polyanions of La_(6)Co_(2)and La_(6)Mn_(2)consist of the uncommon 3d-4f-5d clusters{La_(6)W_(12)Co_(2)}and{La_(6)W_(12)Mn_(2)},which are encapsulated by four trilacunary Keggin tungstoantimonates to form the parallelogram-shaped title compounds.Additionally,the polyanions can be extended into a two-dimensional(2D)frame by the linkage of peripheral Na+ions.The inner space of the 2D layer was filled with water molecules and thus an H-bonded network was formed,which is expected to exhibit a fascinating proton conductivity.The study of water-assisted proton conduction demonstrated that La_(6)Co_(2)and La_(6)Mn_(2)were temperature-and humiditydependent proton conductors,respectively,and the proton conductivities could reach 1.3×10^(-2)and 2.3×10^(-2)S/cm at 65℃and 90%RH conditions.展开更多
Parallel robots with SCARA(selective compliance assembly robot arm) motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parall...Parallel robots with SCARA(selective compliance assembly robot arm) motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parallelogram structures included by the robots as a link. As the established error model fails to reflect the error feature of the parallelogram structures, the effect of accuracy design and kinematic calibration based on the error model come to be undermined. An error modeling methodology is proposed to establish an error model of parallel robots with parallelogram structures. The error model can embody the geometric errors of all joints, including the joints of parallelogram structures. Thus it can contain more exhaustively the factors that reduce the accuracy of the robot. Based on the error model and some sensitivity indices defined in the sense of statistics, sensitivity analysis is carried out. Accordingly, some atlases are depicted to express each geometric error’s influence on the moving platform’s pose errors. From these atlases, the geometric errors that have greater impact on the accuracy of the moving platform are identified, and some sensitive areas where the pose errors of the moving platform are extremely sensitive to the geometric errors are also figured out. By taking into account the error factors which are generally neglected in all existing modeling methods, the proposed modeling method can thoroughly disclose the process of error transmission and enhance the efficacy of accuracy design and calibration.展开更多
The problem of tiling rectangles by polyominoes generated large interest. A related one is the problem of tiling parallelograms by twisted polyominoes. Both problems are related with tilings of (skewed) quadrants by p...The problem of tiling rectangles by polyominoes generated large interest. A related one is the problem of tiling parallelograms by twisted polyominoes. Both problems are related with tilings of (skewed) quadrants by polyominoes. Indeed, if all tilings of a (skewed) quadrant by a tile set can be reduced to a tiling by congruent rectangles (parallelograms), this provides information about tilings of rectangles (parallelograms). We consider a class of tile sets in a square lattice appearing from arbitrary dissections of rectangles in two L-shaped polyominoes and from symmetries of these tiles about the first bisector. Only translations of the tiles are allowed in a tiling. If the sides of the dissected rectangle are coprime, we show the existence of tilings of all (skewed) quadrants that do not follow the rectangular (parallelogram) pattern. If one of the sides of the dissected rectangle is 2 and the other is odd, we also show tilings of rectangles by the tile set that do not follow the rectangular pattern. If one of the sides of the dissected rectangle is 2 and the other side is even, we show a new infinite family of tile sets that follows the rectangular pattern when tiling one of the quadrants. For this type of dis-section, we also show a new infinite family that does not follow the rectangular pattern when tiling rectangles. Finally, we investigate more general dissections of rectangles, with. Here we show infinite families of tile sets that follow the rectangular pattern for a quadrant and infinite families that do not follow the rectangular pattern for any quadrant. We also show, for infinite families of tile sets of this type, tilings of rectangles that do not follow the rectangular pattern.展开更多
A wearable passive exoskeleton is proposed for reduced gravity astronauts training.The main component unit of the proposed robotic exoskeleton is the spring-based parallelogram mechanism which can passively balance an...A wearable passive exoskeleton is proposed for reduced gravity astronauts training.The main component unit of the proposed robotic exoskeleton is the spring-based parallelogram mechanism which can passively balance any proportion of the gravity load acting on it through designing an appropriate stiffness of the spring or adjusting the install position of the spring.A conceptual exoskeleton model capable of gravity compensation for upper limbs applying to such technology is designed and the corresponding simulation is presented,in which the muscle activations are collected to show the effectiveness of the design.展开更多
In this paper,according to the cantilever beam of fetching carton mechanism in square packaging machine, considering the impact of motion of air cylinder on it,its dynamics model and finite element model are built by ...In this paper,according to the cantilever beam of fetching carton mechanism in square packaging machine, considering the impact of motion of air cylinder on it,its dynamics model and finite element model are built by using ANSYS. This paper not only acquires the deformation distribution,stress distribution and natural frequency of the cantilever beam in the static state; but also gets the dynamic response curve in the maximum deformation and the dynamic stress response curve in the near of the maximum stress during the motion of air cylinder. Result shows that no matter static state or dynamic state,deformation of the cantilever in the fetching carton mechanism is acceptable. The design of mechanism is reliable and its motion is also stable; no resonance can occur on the cantilever beam.展开更多
My previous work dealt finding numbers which relatively prime to factorial value of certain number, high exponents and also find the way for finding mod values on certain number’s exponents. Firstly, I retreat my pre...My previous work dealt finding numbers which relatively prime to factorial value of certain number, high exponents and also find the way for finding mod values on certain number’s exponents. Firstly, I retreat my previous works about Euler’s phi function and some works on Fermat’s little theorem. Next, I construct exponent parallelogram to find coherence numbers of Euler’s phi functioned numbers and apply to Fermat’s little theorem. Then, I test the primality of prime numbers on Pascal’s triangle and explore new ways to construct Pascal’s triangle. Finally, I find the factorial value for certain number by using exponent triangle.展开更多
In this paper, we introduce and study some new classes of biconvex functions with respect to an arbitrary function and a bifunction, which are called the higher order strongly biconvex functions. These functions are n...In this paper, we introduce and study some new classes of biconvex functions with respect to an arbitrary function and a bifunction, which are called the higher order strongly biconvex functions. These functions are nonconvex functions and include the biconvex function, convex functions, and <i>k</i>-convex as special cases. We study some properties of the higher order strongly biconvex functions. Several parallelogram laws for inner product spaces are obtained as novel applications of the higher order strongly biconvex affine functions. It is shown that the minimum of generalized biconvex functions on the <i>k</i>-biconvex sets can be characterized by a class of equilibrium problems, which is called the higher order strongly biequilibrium problems. Using the auxiliary technique involving the Bregman functions, several new inertial type methods for solving the higher order strongly biequilibrium problem are suggested and investigated. Convergence analysis of the proposed methods is considered under suitable conditions. Several important special cases are obtained as novel applications of the derived results. Some open problems are also suggested for future research.展开更多
Efron (1997) considered several approximations of p-values for simultaneous hypothesis testing. An extension of his approaches is considered here to approximate various probabilities of correlated events. Compared wit...Efron (1997) considered several approximations of p-values for simultaneous hypothesis testing. An extension of his approaches is considered here to approximate various probabilities of correlated events. Compared with multiple-integrations, our proposed method, the parallelogram formulas, based on a one-dimensional integral, not only substantially reduces the computational complexity but also maintains good accuracy. Applications of the proposed method to genetic association studies and group sequential analysis are investigated in detail. Numerical results including real data analysis and simulation studies demonstrate that the proposed method performs well.展开更多
Compliant translational joints (CTJs) have been extensively used in precision engineering and microelectromechanical systems (MEMS). There is an increasing need for designing higher-performance CTJs. This paper de...Compliant translational joints (CTJs) have been extensively used in precision engineering and microelectromechanical systems (MEMS). There is an increasing need for designing higher-performance CTJs. This paper deals with the conceptual design of CTJs via three approaches: parallelogram based method, straight- line motion mechanism based method and combination based method. Typical emerging CTJ designs are reviewed by explaining their design principles and qualitatively analyzing their characteristics. New CTJs are proposed using three approaches, including an asymmetric double parallelogram mechanism with slaving mechanism, several compact and symmetric double parallelogram mechanisms with slaving mechanisms and a general CTJ using the center drift compensation and a CTJ using Roberts linkage and several combination designs. This paper provides an overview of the current advances/progresses of CTJ designs and lays the foundation for further optimization, quantitative analysis and characteristic comparisons.展开更多
文摘The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical
文摘We are responsible for providing energy and food resources for our next generation.After more than 20 years of research,the author has confirmed that the VAWT with flip-up mechanism can maintain rotation without the brake,even in strong winds.Experiments have shown that the triangularly coupled movable parallelogram buoyancy structure makes it easy to maintain the verticality of the wind turbine tower even under large waves.Furthermore,as a result of studying the connection between the HAWT(horizontal axis wind turbine)and the movable parallelogram buoyancy structure of the triangular connection,the feasibility was confirmed.The only way for all people in the world to secure energy and food fairly is to look for the remaining areas such as the high seas.The author would like to propose the use of the high seas to combat global hunger,which is likely to be a global problem in the future.
文摘In this paper, the effect of thermal gradient on the vibration of parallelogram plate with linearly varying thickness in both direction having clamped boundary conditions on all the four edges is analyzed. Thermal effect on vibration of such plate has been taken as one-dimensional distribution in linear form only. An approximate but quiet convenient frequency equation is derived using Rayleigh-Ritz technique with a two-term deflection function. The frequencies corresponding to the first two modes of vibration of a clamped parallelogram plate have been computed for different values of aspect ratio, thermal gradient, taper constants and skew angle. The results have been presented in tabular forms. The results obtained in this study are reduced to that of unheated parallelogram plates of uniform thickness and have generally been compared with the published one.
文摘Let G = (V,E) be a graph, where V(G) is a non-empty set of vertices and E(G) is a set of edges, e = uv∈E(G), d(u) is degree of vertex u. Then the first Zagreb polynomial and the first Zagreb index Zg<sub>1</sub>(G,x) and Zg<sub>1</sub>(G) of the graph G are defined as Σ<sub>uv∈E(G)</sub>x<sup>(d<sub>u</sub>+d<sub>v</sub>)</sup> and Σ<sub>e=uv∈E(G)</sub>(d<sub>u</sub>+d<sub>v</sub>) respectively. Recently Ghorbani and Hosseinzadeh introduced the first Eccentric Zagreb index as Zg<sub>1</sub>*</sup>=Σ<sub>uv∈E(G)</sub>(ecc(v)+ecc(u)), that ecc(u) is the largest distance between u and any other vertex v of G. In this paper, we compute this new index (the first Eccentric Zagreb index or third Zagreb index) of an infinite family of linear Polycene parallelogram of benzenoid.
基金supported by the National Natural Science Foundation of China(No.22071045)the Excellent Youth Science Fund Project of Henan Province(No.202300410042)+2 种基金the Natural Science Foundation of Henan Province(No.232300420372)Henan Universitythe State Key Laboratory of Physical Chemistry of the Solid Surface of Xiamen University。
文摘Two 3d-4f-5d heterometallic cluster-containing polyoxometalates,formulated as Na_(22){(SbW_(9)O_(33))_(4)[La_(3)W_(6)MO_(18)(H_(2)O)_(8)(CH_(3)COO)_(4)]_(2)}·nH_(2)O(abbreviated as La_(6)M_(2),M=Co/Mn)were synthesized and structurally characterized.Single-crystal X-ray diffraction analyses reveal that the polyanions of La_(6)Co_(2)and La_(6)Mn_(2)consist of the uncommon 3d-4f-5d clusters{La_(6)W_(12)Co_(2)}and{La_(6)W_(12)Mn_(2)},which are encapsulated by four trilacunary Keggin tungstoantimonates to form the parallelogram-shaped title compounds.Additionally,the polyanions can be extended into a two-dimensional(2D)frame by the linkage of peripheral Na+ions.The inner space of the 2D layer was filled with water molecules and thus an H-bonded network was formed,which is expected to exhibit a fascinating proton conductivity.The study of water-assisted proton conduction demonstrated that La_(6)Co_(2)and La_(6)Mn_(2)were temperature-and humiditydependent proton conductors,respectively,and the proton conductivities could reach 1.3×10^(-2)and 2.3×10^(-2)S/cm at 65℃and 90%RH conditions.
基金Supported by National Natural Science Foundation of China(Grant No.51305222)National Key Scientific and Technological Program of China(Grant No.2013ZX04001-021)
文摘Parallel robots with SCARA(selective compliance assembly robot arm) motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parallelogram structures included by the robots as a link. As the established error model fails to reflect the error feature of the parallelogram structures, the effect of accuracy design and kinematic calibration based on the error model come to be undermined. An error modeling methodology is proposed to establish an error model of parallel robots with parallelogram structures. The error model can embody the geometric errors of all joints, including the joints of parallelogram structures. Thus it can contain more exhaustively the factors that reduce the accuracy of the robot. Based on the error model and some sensitivity indices defined in the sense of statistics, sensitivity analysis is carried out. Accordingly, some atlases are depicted to express each geometric error’s influence on the moving platform’s pose errors. From these atlases, the geometric errors that have greater impact on the accuracy of the moving platform are identified, and some sensitive areas where the pose errors of the moving platform are extremely sensitive to the geometric errors are also figured out. By taking into account the error factors which are generally neglected in all existing modeling methods, the proposed modeling method can thoroughly disclose the process of error transmission and enhance the efficacy of accuracy design and calibration.
文摘The problem of tiling rectangles by polyominoes generated large interest. A related one is the problem of tiling parallelograms by twisted polyominoes. Both problems are related with tilings of (skewed) quadrants by polyominoes. Indeed, if all tilings of a (skewed) quadrant by a tile set can be reduced to a tiling by congruent rectangles (parallelograms), this provides information about tilings of rectangles (parallelograms). We consider a class of tile sets in a square lattice appearing from arbitrary dissections of rectangles in two L-shaped polyominoes and from symmetries of these tiles about the first bisector. Only translations of the tiles are allowed in a tiling. If the sides of the dissected rectangle are coprime, we show the existence of tilings of all (skewed) quadrants that do not follow the rectangular (parallelogram) pattern. If one of the sides of the dissected rectangle is 2 and the other is odd, we also show tilings of rectangles by the tile set that do not follow the rectangular pattern. If one of the sides of the dissected rectangle is 2 and the other side is even, we show a new infinite family of tile sets that follows the rectangular pattern when tiling one of the quadrants. For this type of dis-section, we also show a new infinite family that does not follow the rectangular pattern when tiling rectangles. Finally, we investigate more general dissections of rectangles, with. Here we show infinite families of tile sets that follow the rectangular pattern for a quadrant and infinite families that do not follow the rectangular pattern for any quadrant. We also show, for infinite families of tile sets of this type, tilings of rectangles that do not follow the rectangular pattern.
基金sponsored by the Foundation of Graduate Innovation Center in NUAA(No.kfjj20161502)the Regulation of Ministry of Education of the People’s Republic of Chinasupported by"the Fundamental Research Funds for the Central Universities"
文摘A wearable passive exoskeleton is proposed for reduced gravity astronauts training.The main component unit of the proposed robotic exoskeleton is the spring-based parallelogram mechanism which can passively balance any proportion of the gravity load acting on it through designing an appropriate stiffness of the spring or adjusting the install position of the spring.A conceptual exoskeleton model capable of gravity compensation for upper limbs applying to such technology is designed and the corresponding simulation is presented,in which the muscle activations are collected to show the effectiveness of the design.
基金Program for Changjiang Scholars and Innovative Research Team in University,China(No.IRT1220)Donghua University Thesis Innovation Fund,China(No.EG2014028)
文摘In this paper,according to the cantilever beam of fetching carton mechanism in square packaging machine, considering the impact of motion of air cylinder on it,its dynamics model and finite element model are built by using ANSYS. This paper not only acquires the deformation distribution,stress distribution and natural frequency of the cantilever beam in the static state; but also gets the dynamic response curve in the maximum deformation and the dynamic stress response curve in the near of the maximum stress during the motion of air cylinder. Result shows that no matter static state or dynamic state,deformation of the cantilever in the fetching carton mechanism is acceptable. The design of mechanism is reliable and its motion is also stable; no resonance can occur on the cantilever beam.
文摘My previous work dealt finding numbers which relatively prime to factorial value of certain number, high exponents and also find the way for finding mod values on certain number’s exponents. Firstly, I retreat my previous works about Euler’s phi function and some works on Fermat’s little theorem. Next, I construct exponent parallelogram to find coherence numbers of Euler’s phi functioned numbers and apply to Fermat’s little theorem. Then, I test the primality of prime numbers on Pascal’s triangle and explore new ways to construct Pascal’s triangle. Finally, I find the factorial value for certain number by using exponent triangle.
文摘In this paper, we introduce and study some new classes of biconvex functions with respect to an arbitrary function and a bifunction, which are called the higher order strongly biconvex functions. These functions are nonconvex functions and include the biconvex function, convex functions, and <i>k</i>-convex as special cases. We study some properties of the higher order strongly biconvex functions. Several parallelogram laws for inner product spaces are obtained as novel applications of the higher order strongly biconvex affine functions. It is shown that the minimum of generalized biconvex functions on the <i>k</i>-biconvex sets can be characterized by a class of equilibrium problems, which is called the higher order strongly biequilibrium problems. Using the auxiliary technique involving the Bregman functions, several new inertial type methods for solving the higher order strongly biequilibrium problem are suggested and investigated. Convergence analysis of the proposed methods is considered under suitable conditions. Several important special cases are obtained as novel applications of the derived results. Some open problems are also suggested for future research.
基金supported by the Intramural Program of NIHsupported in part by National Natural Science Foundation of China (Grant No.10901155)supportedin part by NIH (Grant No. EY014478).
文摘Efron (1997) considered several approximations of p-values for simultaneous hypothesis testing. An extension of his approaches is considered here to approximate various probabilities of correlated events. Compared with multiple-integrations, our proposed method, the parallelogram formulas, based on a one-dimensional integral, not only substantially reduces the computational complexity but also maintains good accuracy. Applications of the proposed method to genetic association studies and group sequential analysis are investigated in detail. Numerical results including real data analysis and simulation studies demonstrate that the proposed method performs well.
文摘Compliant translational joints (CTJs) have been extensively used in precision engineering and microelectromechanical systems (MEMS). There is an increasing need for designing higher-performance CTJs. This paper deals with the conceptual design of CTJs via three approaches: parallelogram based method, straight- line motion mechanism based method and combination based method. Typical emerging CTJ designs are reviewed by explaining their design principles and qualitatively analyzing their characteristics. New CTJs are proposed using three approaches, including an asymmetric double parallelogram mechanism with slaving mechanism, several compact and symmetric double parallelogram mechanisms with slaving mechanisms and a general CTJ using the center drift compensation and a CTJ using Roberts linkage and several combination designs. This paper provides an overview of the current advances/progresses of CTJ designs and lays the foundation for further optimization, quantitative analysis and characteristic comparisons.