This study analyzes how economic policy uncertainty affects corporate innovation,and the moderating effects of executive heterogeneity.A threephase dynamic investment and financing model is first built to analyze the ...This study analyzes how economic policy uncertainty affects corporate innovation,and the moderating effects of executive heterogeneity.A threephase dynamic investment and financing model is first built to analyze the mechanism.Empirical analysis confirms that the increase in the degree of economic policy uncertainty promotes enterprise innovation.Further results show that this promotion effect is more significant in enterprises with male executives,low educational level,no financial experience and political background.Moreover,the positive impact is only found in enterprises with moderate executive ability,and the overconfidence of senior executives plays a positive regulating role in it.展开更多
Many studies revealed that the Earth medium＇s lateral heterogeneity can cause considerable effects on the co- and post-seismic deformation field. In this study, the threedimensional finite element numerical method ar...Many studies revealed that the Earth medium＇s lateral heterogeneity can cause considerable effects on the co- and post-seismic deformation field. In this study, the threedimensional finite element numerical method are adopted to quantify the effects of lateral heterogeneity caused by material parameters and fault dip angle on the co- and postseismic deformation in the near- and far-field. Our results show that： 1） the medium＇s lateral heterogeneity does affect the co-seismic deformation, with the effects increasing with the medium＇s lateral heterogeneity caused by material parameters; 2） the Lame parameters play a more dominant role than density in the effects caused by lateral heterogeneity; 3） when a fault＇s dip angle is smaller than 90, the effects of the medium＇s lateral heterogeneity on the hanging wall are greater than on the footwall; 4） the impact of lateral heterogeneity caused by the viscosity coefficient on the post-seismic deformation can affect a large area, including the near- and far-field.展开更多
Subthalamic nucleus deep brain stimulation (STN DBS) is an effective treatment for medically refractory Parkinson’s disease (PD). However, a minority of patients develop cognitive problems, particularly a decline of ...Subthalamic nucleus deep brain stimulation (STN DBS) is an effective treatment for medically refractory Parkinson’s disease (PD). However, a minority of patients develop cognitive problems, particularly a decline of executive function in the early period after STN DBS. Although this problem is usually transient, it may cause social maladjustment. We investigated factors affecting early decline of executive function after STN-DBS. Fifty-seven patients whose preoperative global cognitive screening was normal (MMSE score;28 or more) were enrolled in this study. Executive function was evaluated with the Trail-Making Test (TMT) preoperatively and 1-month after surgery. We considered a patient to have decline in executive function if the TMT (B-A) was prolonged more than 30 seconds after STN DBS. Among 57 patients, 25 patients were categorized as having decline of executive function. Univariate analysis revealed that high preoperative UPDRS III motor score in the medication-off period and a depressive state evaluated with BDI-II correlated significantly with decline in executive function. Multiple logistic regression analysis revealed that the only significant independent variable related to early decline of executive function was the preoperative BDI-II score. Postoperative factors such as active contact location or dopaminergic medication reduction had no relation with the decline of executive function. Even in cognitively well-selected patients, STN DBS causes early decline in executive function in a significant number of patients. Preoperative simple cognitive screening alone could not predict early decline in executive function. More detailed neuropsychological evaluation, including mood status, should be undertaken before surgery.展开更多
Maritime radar and automatic identification systems (AIS), which are essential auxiliary equipment for navigation safety in the shipping industry, have played significant roles in maritime safety supervision. However,...Maritime radar and automatic identification systems (AIS), which are essential auxiliary equipment for navigation safety in the shipping industry, have played significant roles in maritime safety supervision. However, in practical applications, the information obtained by a single device is limited, and it is necessary to integrate the information of maritime radar and AIS messages to achieve better recognition effects. In this study, the D-S evidence theory is used to fusion the two kinds of heterogeneous information: maritime radar images and AIS messages. Firstly, the radar image and AIS message are processed to get the targets of interest in the same coordinate system. Then, the coordinate position and heading of targets are chosen as the indicators for judging target similarity. Finally, a piece of D-S evidence theory based on the information fusion method is proposed to match the radar target and the AIS target of the same ship. Particularly, the effectiveness of the proposed method has been validated and evaluated through several experiments, which proves that such a method is practical in maritime safety supervision.展开更多
Macroeconomic Overview:The U.S.dollar has fallen 4%against a broad collection of widely circulated currencies since January.While the magnitude of the decline may not appear large,it does signal an important reversal ...Macroeconomic Overview:The U.S.dollar has fallen 4%against a broad collection of widely circulated currencies since January.While the magnitude of the decline may not appear large,it does signal an important reversal relative to recent years.Against the same broad collection of currencies,the U.S.dollar had consistently strengthened since 2013。展开更多
The homogeneous and heterogeneous reactions in the boundary-layer of a flat surface are considered. The autocatalysts are assumed to be of regular sizes, while the solution is a dilute nanofluid. The heat release due ...The homogeneous and heterogeneous reactions in the boundary-layer of a flat surface are considered. The autocatalysts are assumed to be of regular sizes, while the solution is a dilute nanofluid. The heat release due to the chemical reactions is taken into account. The Buongiorno’s model is used to describe the behaviors of this reaction system. This configuration makes the current model be different from all previous publications. Multiple solutions are given numerically to the rescaled nonlinear system, whose stability is verified. The results show that the strength coefficients of the homogeneous and heterogeneous reactions are key factors to cause the appearance of the multiple solutions in the distribution of the chemical reactions. Nanofluids enhance the diffusion of heat and help maintain the stability of chemical reactions.展开更多
The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves a...The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves are calculated numerically as a function of kH and presented in a number of graphs, where k is the wave number, and H is the thickness of the layer. The case of Gibson＇s half-space is also considered. It is observed that the speed of Love waves is finite in the vicinity of the surface of the half-space and vanishes as the depth increases for a particular wave number. It is also observed that an increase in compressive initial stresses causes decreases of Love waves velocity for the same frequency, and the tensile initial stress of small magnitude in the half-space causes increase of the velocity.展开更多
Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malwar...Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malware propagation in this paper.Firstly,a heterogeneous-susceptible-exposed-infectious-recovered-susceptible(HSEIRS)model is proposed to describe the state dynamics of heterogeneous sensor nodes(HSNs)in HWSNs.Secondly,the existence of an optimal control problem with installing antivirus on HSNs to minimize the sum of the cumulative infection probabilities of HWSNs at a low cost based on the HSEIRS model is proved,and then an optimal control strategy for the problem is derived by the optimal control theory.Thirdly,the optimal control strategy based on the HSEIRS model is transformed into corresponding Hamiltonian by the Pontryagin’s minimum principle,and the corresponding optimality system is derived.Finally,the effectiveness of the optimality system is validated by the experimental simulations,and the results show that the infectious HSNs will fall to an extremely low level at a low cost.展开更多
基金the support of Humanities and Social Sciences Foundation of the Ministry of Education"Research on policy uncertainty,non-financial enterprises’shadow banking activities and its economic effects"(20YJC790040)School Level Special Research Project of Beijing International Studies University(KYZX20A008).
文摘This study analyzes how economic policy uncertainty affects corporate innovation,and the moderating effects of executive heterogeneity.A threephase dynamic investment and financing model is first built to analyze the mechanism.Empirical analysis confirms that the increase in the degree of economic policy uncertainty promotes enterprise innovation.Further results show that this promotion effect is more significant in enterprises with male executives,low educational level,no financial experience and political background.Moreover,the positive impact is only found in enterprises with moderate executive ability,and the overconfidence of senior executives plays a positive regulating role in it.
基金co-supported by the National Natural Science Foundation of China (41431069)the State Key Development Program for Basic Research of China (2013CB733304, 2013CB733303)+1 种基金the Doctoral Fund of Ministry of Education of China (20110141130010)China Postdoctoral Science Foundation funded project (2013M542062)
文摘Many studies revealed that the Earth medium＇s lateral heterogeneity can cause considerable effects on the co- and post-seismic deformation field. In this study, the threedimensional finite element numerical method are adopted to quantify the effects of lateral heterogeneity caused by material parameters and fault dip angle on the co- and postseismic deformation in the near- and far-field. Our results show that： 1） the medium＇s lateral heterogeneity does affect the co-seismic deformation, with the effects increasing with the medium＇s lateral heterogeneity caused by material parameters; 2） the Lame parameters play a more dominant role than density in the effects caused by lateral heterogeneity; 3） when a fault＇s dip angle is smaller than 90, the effects of the medium＇s lateral heterogeneity on the hanging wall are greater than on the footwall; 4） the impact of lateral heterogeneity caused by the viscosity coefficient on the post-seismic deformation can affect a large area, including the near- and far-field.
文摘Subthalamic nucleus deep brain stimulation (STN DBS) is an effective treatment for medically refractory Parkinson’s disease (PD). However, a minority of patients develop cognitive problems, particularly a decline of executive function in the early period after STN DBS. Although this problem is usually transient, it may cause social maladjustment. We investigated factors affecting early decline of executive function after STN-DBS. Fifty-seven patients whose preoperative global cognitive screening was normal (MMSE score;28 or more) were enrolled in this study. Executive function was evaluated with the Trail-Making Test (TMT) preoperatively and 1-month after surgery. We considered a patient to have decline in executive function if the TMT (B-A) was prolonged more than 30 seconds after STN DBS. Among 57 patients, 25 patients were categorized as having decline of executive function. Univariate analysis revealed that high preoperative UPDRS III motor score in the medication-off period and a depressive state evaluated with BDI-II correlated significantly with decline in executive function. Multiple logistic regression analysis revealed that the only significant independent variable related to early decline of executive function was the preoperative BDI-II score. Postoperative factors such as active contact location or dopaminergic medication reduction had no relation with the decline of executive function. Even in cognitively well-selected patients, STN DBS causes early decline in executive function in a significant number of patients. Preoperative simple cognitive screening alone could not predict early decline in executive function. More detailed neuropsychological evaluation, including mood status, should be undertaken before surgery.
文摘Maritime radar and automatic identification systems (AIS), which are essential auxiliary equipment for navigation safety in the shipping industry, have played significant roles in maritime safety supervision. However, in practical applications, the information obtained by a single device is limited, and it is necessary to integrate the information of maritime radar and AIS messages to achieve better recognition effects. In this study, the D-S evidence theory is used to fusion the two kinds of heterogeneous information: maritime radar images and AIS messages. Firstly, the radar image and AIS message are processed to get the targets of interest in the same coordinate system. Then, the coordinate position and heading of targets are chosen as the indicators for judging target similarity. Finally, a piece of D-S evidence theory based on the information fusion method is proposed to match the radar target and the AIS target of the same ship. Particularly, the effectiveness of the proposed method has been validated and evaluated through several experiments, which proves that such a method is practical in maritime safety supervision.
文摘Macroeconomic Overview:The U.S.dollar has fallen 4%against a broad collection of widely circulated currencies since January.While the magnitude of the decline may not appear large,it does signal an important reversal relative to recent years.Against the same broad collection of currencies,the U.S.dollar had consistently strengthened since 2013。
基金the National Natural Science Foundation of China(Nos.11872241 and11432009)。
文摘The homogeneous and heterogeneous reactions in the boundary-layer of a flat surface are considered. The autocatalysts are assumed to be of regular sizes, while the solution is a dilute nanofluid. The heat release due to the chemical reactions is taken into account. The Buongiorno’s model is used to describe the behaviors of this reaction system. This configuration makes the current model be different from all previous publications. Multiple solutions are given numerically to the rescaled nonlinear system, whose stability is verified. The results show that the strength coefficients of the homogeneous and heterogeneous reactions are key factors to cause the appearance of the multiple solutions in the distribution of the chemical reactions. Nanofluids enhance the diffusion of heat and help maintain the stability of chemical reactions.
文摘The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves are calculated numerically as a function of kH and presented in a number of graphs, where k is the wave number, and H is the thickness of the layer. The case of Gibson＇s half-space is also considered. It is observed that the speed of Love waves is finite in the vicinity of the surface of the half-space and vanishes as the depth increases for a particular wave number. It is also observed that an increase in compressive initial stresses causes decreases of Love waves velocity for the same frequency, and the tensile initial stress of small magnitude in the half-space causes increase of the velocity.
基金National Natural Science Foundation of China(No.61772018)Zhejiang Provincial Natural Science Foundation of China(No.LZ22F020002)。
文摘Heterogeneous wireless sensor networks(HWSNs)are vulnerable to malware propagation,because of their low configuration and weak defense mechanism.Therefore,an optimality system for HWSNs is developed to suppress malware propagation in this paper.Firstly,a heterogeneous-susceptible-exposed-infectious-recovered-susceptible(HSEIRS)model is proposed to describe the state dynamics of heterogeneous sensor nodes(HSNs)in HWSNs.Secondly,the existence of an optimal control problem with installing antivirus on HSNs to minimize the sum of the cumulative infection probabilities of HWSNs at a low cost based on the HSEIRS model is proved,and then an optimal control strategy for the problem is derived by the optimal control theory.Thirdly,the optimal control strategy based on the HSEIRS model is transformed into corresponding Hamiltonian by the Pontryagin’s minimum principle,and the corresponding optimality system is derived.Finally,the effectiveness of the optimality system is validated by the experimental simulations,and the results show that the infectious HSNs will fall to an extremely low level at a low cost.
