针对国际石油市场与中美股票市场出现的跳跃聚集现象和互激励效应,本文首先通过引入Hawkes过程构建了互激励跳跃扩散模型,对国际油价与中美股价间跳跃溢出效应开展研究;然后运用广义矩估计法(Generalized Method of Moments,GMM)估计模...针对国际石油市场与中美股票市场出现的跳跃聚集现象和互激励效应,本文首先通过引入Hawkes过程构建了互激励跳跃扩散模型,对国际油价与中美股价间跳跃溢出效应开展研究;然后运用广义矩估计法(Generalized Method of Moments,GMM)估计模型的参数并分析了国际石油市场和中美股市间跳跃溢出效应的方向和程度,同时对跳跃溢出效应的显著性进行Wald检验;最后通过模拟过程的成功率(Success Rate,SR)和误判率(Misjudgment Rate,MR)对互激励跳跃扩散模型测度跳跃溢出效应的有效性进行评价.实证结果表明:国际石油市场与中美股市不仅单个市场收益率存在跳跃聚集现象、自激励效应,而且相互之间跳跃具有明显的非对称互激励效应,石油价格跳跃对股票指数的影响显著强于股票指数跳跃对石油价格的影响;国际油价的跳跃对中国股票指数的影响明显强于美国,一旦国际石油价格发生跳跃,会刺激中国股指频繁跳跃,而对美国股市影响较践ald检验结果进一步验证了国际油价和中美股价间跳跃溢出效应结论的可靠性,而成功率(SR)和误判率(MR)则表明互激励扩散模型测度自激励、非对称互激励跳跃溢出效应准确有效.展开更多
Today＇s society has entered the Intemet era, the Internet technology has brought great changes to all walks of life.With the development of＂Internet plus＂,traditional industry, service industry and business have to...Today＇s society has entered the Intemet era, the Internet technology has brought great changes to all walks of life.With the development of＂Internet plus＂,traditional industry, service industry and business have to make the appropriate changes to meet the demand of the ＂Internet plus＂ era.Similarly,human resource management has to face new challenges in ＂Intemet plus＂ era.This paper expounds the characteristics of＂Internet plus＂ era and the changes brought to the human resource management,put forward the idea that human resources management should make changes to meet the demand of the ＂Internet plus＂ era from three aspects：big data,decentration and staff self management,establishing a new talent incentive mechanism.展开更多
With the continuous development of Internet technology, the network has become an important part of people＇s lives, the emergence of virtual communities is promoting the deep interaction oflntemet users, but it is fo...With the continuous development of Internet technology, the network has become an important part of people＇s lives, the emergence of virtual communities is promoting the deep interaction oflntemet users, but it is found that the virtual community ＂diving party＂ is more and more through investigation and literature research, The quantity and quality of knowledge sharing are declining. Therefore, this paper summarizes the behavior and influencing factors of knowledge sharing in virtual community through literature research and investigation and research. At the same time, through the research of incentive theory, the author has obtained the incentive method and content of knowledge sharing, and established the incentive mechanism. The bright spot is to perfect the theory of knowledge sharing while transforming theory into practice, and to provide suggestions for the development of incentive mechanism of virtual community.展开更多
Corporate governance is the focus of all stakeholders in the balance of contradictions and conflicts in the view of corporatc behavior theory, harmonious governance may be the development direction of future corporate...Corporate governance is the focus of all stakeholders in the balance of contradictions and conflicts in the view of corporatc behavior theory, harmonious governance may be the development direction of future corporate governance. The article explains the framework of harmonious governance based on the theory of corporate behavior, and holds that shareholder value and stakeholder value is as important as, combination of incentive-compatible and mutually compatible, interaction between market governance and relationship governance, is a major innovation path of harmonious corporate governance by stakeholders.展开更多
The non-cooperative action in the social dilemma situation might, at the worst case, lead to violation of social rules （or regulations）. A repetitive N-person social dilemma game that permit the participants to chan...The non-cooperative action in the social dilemma situation might, at the worst case, lead to violation of social rules （or regulations）. A repetitive N-person social dilemma game that permit the participants to change jobs between organizations （groups） and mutually interact between groups was carried out to investigate how ＂limitation for job change＂, ＂cost for job change＂, and ＂incentive （enhancement of personal career）＂ affected the cooperation. The cost for job change effectively worked for the enhancement of cooperation. When the cost for job change was not necessary, the cooperative behavior was enhanced. When the cost for job change was necessary, it tended that a non-cooperative action was selected. When the limitation and the cost for job change were imposed, and the participants were provided with the incentive for cooperation, the cooperation rate was the highest. A significant interaction between the incentive condition （enhancement of personal career） and the limitation for job change was also clarified.展开更多
A reduced three-degree-of-freedom model simulating the fluid-structure interactions （FSI） of the turbine blades and the on- coming air flows is proposed. The equations of motions consist of the coupling of bending a...A reduced three-degree-of-freedom model simulating the fluid-structure interactions （FSI） of the turbine blades and the on- coming air flows is proposed. The equations of motions consist of the coupling of bending and torsion of a blade as well as a van der Pol oscillation which represents the time-varying of the fluid. The 1：1 internal resonance of the system is analyzed with the multiple scale method, and the modulation equations are derived. The two-parameter bifurcation diagrams are computed. The effects of the system parameters, including the detuning parameter and the reduced frequency, on responses of the struc- ture and fluid are investigated. Bifurcation curves are computed and the stability is determined by examining the eigenvalues of the Jacobian matrix. The results indicate that rich dynamic phenomena of the steady-state solutions including the sad- dle-node and Hopf bifurcations can occur under certain parameter conditions. The parameter region where the unstable solu- tions occur should be avoided to keep the safe operation of the blades. The analytical solutions are verified by the direct nu- merical simulations.展开更多
A frequency and amplitude dependent model is used to describe the complex behavior of rail pads. It is implemented into the dynamic analysis of three dimensional coupled vehicle-slab track （3D-CVST） systems. The veh...A frequency and amplitude dependent model is used to describe the complex behavior of rail pads. It is implemented into the dynamic analysis of three dimensional coupled vehicle-slab track （3D-CVST） systems. The vehicle is treated as a 35-degree- of-freedom multi-body system, and the slab track is represented by two continuous Bernoulli-Euler beams supported by a se- ries of elastic rectangle plates on a viscoelastic foundation. The rail pad model takes into account the influences of the excita- tion frequency and of the displacement amplitude through a fractional derivative element, and a nonlinear friction element, re- spectively. The Granwald representation of the fractional derivatives is employed to numerically solve the fractional and non- linear equations of motion of the 3D-CVST system by means of an explicit integration algorithm. A dynamic analysis of the 3D-CVST system exposed to excitations of rail harmonic irregularities is primarily carried out, which reveals the dependence of stiffness and damping on excitation frequency and displacement amplitude. Subsequently, sensitive analyses of the model parameters are investigated by conducting the dynamic analysis of the 3D-CVST system subjected to excitations of welded rail joint irregularities. Following this, parameters of the rail pad model are optimized with respect to experimental values. For elu- cidation, the 3D-CVST dynamic model incorporated with the rail pads model is used to calculate the wheel/rail forces induced by excitations of measured random track irregularities. Further, the numerical results are compared with experimental data, demonstrating the reliability of the proposed model.展开更多
This study demonstrates the potential for shock wave-boundary layer interaction control in air by plasma aerodynamic actuation.Experimental investigations on shock wave-boundary layer interactions control by plasma ae...This study demonstrates the potential for shock wave-boundary layer interaction control in air by plasma aerodynamic actuation.Experimental investigations on shock wave-boundary layer interactions control by plasma aerodynamic actuation are conducted in a Mach 3 in-draft air tunnel.Schlieren imaging shows that the discharges cause the oblique shock to move forward.Schlieren imaging and static pressure probes also show that separation phenomenon shifts backward and the size of separation is enlarged when plasma aerodynamic actuation is applied.The intensity of shock wave is weakened through wall pressure probe.Furthermore,numerical investigations on shock wave-boundary layer interactions control are conducted with plasma aerodynamic actuation.The discharge is modeled as a steady volumetric heat source which is integrated into the energy equation.The input energy level is about 7 kW through discharge process.Results show that the separation phenomenon shifts backward and the intensity of shock is reduced with plasma actuation.These numerical results are consistent with the experimental results.展开更多
Rotor blades in a radial turbine with nozzle guide vanes typically experience harmonic aerodynamic excitations due to the rotor stator interaction. Dynamic stresses induced by the harmonic excitations can result in hi...Rotor blades in a radial turbine with nozzle guide vanes typically experience harmonic aerodynamic excitations due to the rotor stator interaction. Dynamic stresses induced by the harmonic excitations can result in high cycle fatigue(HCF) of the blades. A reliable prediction method for forced response issue is essential to avoid the HCF problem. In this work, the forced response mechanisms were investigated based on a fluid structure interaction(FSI) method. Aerodynamic excitations were obtained by three-dimensional unsteady computational fluid dynamics(CFD) simulation with phase shifted periodic boundary conditions. The first two harmonic pressures were determined as the primary components of the excitation and applied to finite element(FE) model to conduct the computational structural dynamics(CSD) simulation. The computed results from the harmonic forced response analysis show good agreement with the predictions of Singh's advanced frequency evaluation(SAFE) diagram. Moreover, the mode superposition method used in FE simulation offers an efficient way to provide quantitative assessments of mode response levels and resonant strength.展开更多
文摘Today＇s society has entered the Intemet era, the Internet technology has brought great changes to all walks of life.With the development of＂Internet plus＂,traditional industry, service industry and business have to make the appropriate changes to meet the demand of the ＂Internet plus＂ era.Similarly,human resource management has to face new challenges in ＂Intemet plus＂ era.This paper expounds the characteristics of＂Internet plus＂ era and the changes brought to the human resource management,put forward the idea that human resources management should make changes to meet the demand of the ＂Internet plus＂ era from three aspects：big data,decentration and staff self management,establishing a new talent incentive mechanism.
文摘With the continuous development of Internet technology, the network has become an important part of people＇s lives, the emergence of virtual communities is promoting the deep interaction oflntemet users, but it is found that the virtual community ＂diving party＂ is more and more through investigation and literature research, The quantity and quality of knowledge sharing are declining. Therefore, this paper summarizes the behavior and influencing factors of knowledge sharing in virtual community through literature research and investigation and research. At the same time, through the research of incentive theory, the author has obtained the incentive method and content of knowledge sharing, and established the incentive mechanism. The bright spot is to perfect the theory of knowledge sharing while transforming theory into practice, and to provide suggestions for the development of incentive mechanism of virtual community.
文摘Corporate governance is the focus of all stakeholders in the balance of contradictions and conflicts in the view of corporatc behavior theory, harmonious governance may be the development direction of future corporate governance. The article explains the framework of harmonious governance based on the theory of corporate behavior, and holds that shareholder value and stakeholder value is as important as, combination of incentive-compatible and mutually compatible, interaction between market governance and relationship governance, is a major innovation path of harmonious corporate governance by stakeholders.
文摘The non-cooperative action in the social dilemma situation might, at the worst case, lead to violation of social rules （or regulations）. A repetitive N-person social dilemma game that permit the participants to change jobs between organizations （groups） and mutually interact between groups was carried out to investigate how ＂limitation for job change＂, ＂cost for job change＂, and ＂incentive （enhancement of personal career）＂ affected the cooperation. The cost for job change effectively worked for the enhancement of cooperation. When the cost for job change was not necessary, the cooperative behavior was enhanced. When the cost for job change was necessary, it tended that a non-cooperative action was selected. When the limitation and the cost for job change were imposed, and the participants were provided with the incentive for cooperation, the cooperation rate was the highest. A significant interaction between the incentive condition （enhancement of personal career） and the limitation for job change was also clarified.
基金supported by the National Basic Research Program of China(“973” Project)(Grant No.2015CB057405)the National Natural Science Foundation of China(Grant No.11372082)the State Scholarship Fund of CSC
文摘A reduced three-degree-of-freedom model simulating the fluid-structure interactions （FSI） of the turbine blades and the on- coming air flows is proposed. The equations of motions consist of the coupling of bending and torsion of a blade as well as a van der Pol oscillation which represents the time-varying of the fluid. The 1：1 internal resonance of the system is analyzed with the multiple scale method, and the modulation equations are derived. The two-parameter bifurcation diagrams are computed. The effects of the system parameters, including the detuning parameter and the reduced frequency, on responses of the struc- ture and fluid are investigated. Bifurcation curves are computed and the stability is determined by examining the eigenvalues of the Jacobian matrix. The results indicate that rich dynamic phenomena of the steady-state solutions including the sad- dle-node and Hopf bifurcations can occur under certain parameter conditions. The parameter region where the unstable solu- tions occur should be avoided to keep the safe operation of the blades. The analytical solutions are verified by the direct nu- merical simulations.
基金supported by the National Basic Research Program of China("973"Project)(Grant Nos.2013CB036202 and 2013CB036206)the Science and Technology Development Program of China Railway Corporation(Grant No.2014G002-B)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2682013CX029)the 2013 Cultivation Program for the Excellent Doctoral Dissertation of Southwest Jiaotong University
文摘A frequency and amplitude dependent model is used to describe the complex behavior of rail pads. It is implemented into the dynamic analysis of three dimensional coupled vehicle-slab track （3D-CVST） systems. The vehicle is treated as a 35-degree- of-freedom multi-body system, and the slab track is represented by two continuous Bernoulli-Euler beams supported by a se- ries of elastic rectangle plates on a viscoelastic foundation. The rail pad model takes into account the influences of the excita- tion frequency and of the displacement amplitude through a fractional derivative element, and a nonlinear friction element, re- spectively. The Granwald representation of the fractional derivatives is employed to numerically solve the fractional and non- linear equations of motion of the 3D-CVST system by means of an explicit integration algorithm. A dynamic analysis of the 3D-CVST system exposed to excitations of rail harmonic irregularities is primarily carried out, which reveals the dependence of stiffness and damping on excitation frequency and displacement amplitude. Subsequently, sensitive analyses of the model parameters are investigated by conducting the dynamic analysis of the 3D-CVST system subjected to excitations of welded rail joint irregularities. Following this, parameters of the rail pad model are optimized with respect to experimental values. For elu- cidation, the 3D-CVST dynamic model incorporated with the rail pads model is used to calculate the wheel/rail forces induced by excitations of measured random track irregularities. Further, the numerical results are compared with experimental data, demonstrating the reliability of the proposed model.
基金supported by the National Natural Science Foundation of China(Grant Nos.51276197,51207169,11372352)
文摘This study demonstrates the potential for shock wave-boundary layer interaction control in air by plasma aerodynamic actuation.Experimental investigations on shock wave-boundary layer interactions control by plasma aerodynamic actuation are conducted in a Mach 3 in-draft air tunnel.Schlieren imaging shows that the discharges cause the oblique shock to move forward.Schlieren imaging and static pressure probes also show that separation phenomenon shifts backward and the size of separation is enlarged when plasma aerodynamic actuation is applied.The intensity of shock wave is weakened through wall pressure probe.Furthermore,numerical investigations on shock wave-boundary layer interactions control are conducted with plasma aerodynamic actuation.The discharge is modeled as a steady volumetric heat source which is integrated into the energy equation.The input energy level is about 7 kW through discharge process.Results show that the separation phenomenon shifts backward and the intensity of shock is reduced with plasma actuation.These numerical results are consistent with the experimental results.
基金supported by the National Natural Science Foundation of China(Grant No.51276018)
文摘Rotor blades in a radial turbine with nozzle guide vanes typically experience harmonic aerodynamic excitations due to the rotor stator interaction. Dynamic stresses induced by the harmonic excitations can result in high cycle fatigue(HCF) of the blades. A reliable prediction method for forced response issue is essential to avoid the HCF problem. In this work, the forced response mechanisms were investigated based on a fluid structure interaction(FSI) method. Aerodynamic excitations were obtained by three-dimensional unsteady computational fluid dynamics(CFD) simulation with phase shifted periodic boundary conditions. The first two harmonic pressures were determined as the primary components of the excitation and applied to finite element(FE) model to conduct the computational structural dynamics(CSD) simulation. The computed results from the harmonic forced response analysis show good agreement with the predictions of Singh's advanced frequency evaluation(SAFE) diagram. Moreover, the mode superposition method used in FE simulation offers an efficient way to provide quantitative assessments of mode response levels and resonant strength.
