Purpose:Deep brain stimulation(DBS)of the subthalamic nucleus(STN)is an indispensable and effective surgery for patients with primary Parkinson’s disease(PD).Nonetheless,its postoperative effects can be decided by ma...Purpose:Deep brain stimulation(DBS)of the subthalamic nucleus(STN)is an indispensable and effective surgery for patients with primary Parkinson’s disease(PD).Nonetheless,its postoperative effects can be decided by many factors including the optimal programmed stimulation parameters.In this study,we analyzed the correlation between different postoperative programmed stimulation parameters and their efficacy after STN–DBS electrode implantation in patients with PD.Methods:A total of 87 patients underwent electrode implantation and completed at least one year follow-up.Then,various combinations of stimulation parameters,including stimulus intensity,frequency,and pulse width,were examined for their effects on the clinical improvement of the patients.Improvements in motor and nonmotor symptoms were analyzed using Mini-Mental State Examination,Parkinson’s Disease Quality of Life Questionnaire-39,and Unified Parkinson’s Disease Rating Scale(UPDRS)scores before and after surgery.Results:We found significantly improved UPDRS scores,quality of life,and neuropsychiatric symptoms postoperatively considering the findings of the aforementioned stimulation parameters compared with those observed preoperatively.Conclusion:This study provides a better understanding on how pro-grammed stimulation parameters help relieve PD symptoms and improve quality of life in patients with PD undergoing STN–DBS.展开更多
In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distingu...In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distinguished advantage to deal with the logic rules and constraints of a plant. Model predictive control algorithm with moving horizon state estimator （MHE） is presented. The estimator is adopted to estimate the current state of the plant with process disturbance and measurement noise, and the state estimated are utilized in the predictive controller for both regulation and tracking problems of the hybrid system based on MLD model. Off-line parametric programming is adopted and then on-line mixed integer programming problem can be treated as the parameter programming with estimated state as the parameters. A three tank system is used for computer simulation, results show that the proposed MHE based predictive control via parametric programming is effective for hybrid system with model/olant mismatch, and has a potential for the engineering applications.展开更多
A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle ...A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle and parametric quadratic programming method were applied to the analysis of three-dimensional frictional contact problem. The solution of the contact problem was finally reduced to a linear complementarity problem, which was reformulated as a system of nonsmooth equations via an NCP-function. A smoothing approximation to the nonsmooth equations was given by the aggregate function. A Newton method was used to solve the resulting smoothing nonlinear equations. The algorithm presented is easy to understand and implement. The reliability and efficiency of this algorithm are demonstrated both by the numerical experiments of LCP in mathematical way and the examples of contact problems in mechanics.展开更多
This paper deals with the FEEDBACK VERTEX SET problem on undirected graphs, which asks for the existence of a vertex set of bounded size that intersects all cycles. Due it is theoretical and practical importance,the p...This paper deals with the FEEDBACK VERTEX SET problem on undirected graphs, which asks for the existence of a vertex set of bounded size that intersects all cycles. Due it is theoretical and practical importance,the problem has been the subject of intensive study. Motivated by the parameter ecology program we attempt to classify the parameterized and kernelization complexity of FEEDBACK VERTEX SET for a wide range of parameters.We survey known results and present several new complexity classifications. For example, we prove that FEEDBACK VERTEX SET is fixed-parameter tractable parameterized by the vertex-deletion distance to a chordal graph. We also prove that the problem admits a polynomial kernel when parameterized by the vertex-deletion distance to a pseudo forest, a graph in which every connected component has at most one cycle. In contrast, we prove that a slightly smaller parameterization does not allow for a polynomial kernel unless NP coNP=poly and the polynomial-time hierarchy collapses.展开更多
文摘Purpose:Deep brain stimulation(DBS)of the subthalamic nucleus(STN)is an indispensable and effective surgery for patients with primary Parkinson’s disease(PD).Nonetheless,its postoperative effects can be decided by many factors including the optimal programmed stimulation parameters.In this study,we analyzed the correlation between different postoperative programmed stimulation parameters and their efficacy after STN–DBS electrode implantation in patients with PD.Methods:A total of 87 patients underwent electrode implantation and completed at least one year follow-up.Then,various combinations of stimulation parameters,including stimulus intensity,frequency,and pulse width,were examined for their effects on the clinical improvement of the patients.Improvements in motor and nonmotor symptoms were analyzed using Mini-Mental State Examination,Parkinson’s Disease Quality of Life Questionnaire-39,and Unified Parkinson’s Disease Rating Scale(UPDRS)scores before and after surgery.Results:We found significantly improved UPDRS scores,quality of life,and neuropsychiatric symptoms postoperatively considering the findings of the aforementioned stimulation parameters compared with those observed preoperatively.Conclusion:This study provides a better understanding on how pro-grammed stimulation parameters help relieve PD symptoms and improve quality of life in patients with PD undergoing STN–DBS.
文摘In this article, state feedback predictive controller for hybrid system via parametric programming is proposed. First, mixed logic dynamic （MLD） modeling mechanism for hybrid system is analyzed, which has a distinguished advantage to deal with the logic rules and constraints of a plant. Model predictive control algorithm with moving horizon state estimator （MHE） is presented. The estimator is adopted to estimate the current state of the plant with process disturbance and measurement noise, and the state estimated are utilized in the predictive controller for both regulation and tracking problems of the hybrid system based on MLD model. Off-line parametric programming is adopted and then on-line mixed integer programming problem can be treated as the parameter programming with estimated state as the parameters. A three tank system is used for computer simulation, results show that the proposed MHE based predictive control via parametric programming is effective for hybrid system with model/olant mismatch, and has a potential for the engineering applications.
文摘A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle and parametric quadratic programming method were applied to the analysis of three-dimensional frictional contact problem. The solution of the contact problem was finally reduced to a linear complementarity problem, which was reformulated as a system of nonsmooth equations via an NCP-function. A smoothing approximation to the nonsmooth equations was given by the aggregate function. A Newton method was used to solve the resulting smoothing nonlinear equations. The algorithm presented is easy to understand and implement. The reliability and efficiency of this algorithm are demonstrated both by the numerical experiments of LCP in mathematical way and the examples of contact problems in mechanics.
基金supported by the European Research Council through Starting Grant 306992 "Parameterized Approximation"
文摘This paper deals with the FEEDBACK VERTEX SET problem on undirected graphs, which asks for the existence of a vertex set of bounded size that intersects all cycles. Due it is theoretical and practical importance,the problem has been the subject of intensive study. Motivated by the parameter ecology program we attempt to classify the parameterized and kernelization complexity of FEEDBACK VERTEX SET for a wide range of parameters.We survey known results and present several new complexity classifications. For example, we prove that FEEDBACK VERTEX SET is fixed-parameter tractable parameterized by the vertex-deletion distance to a chordal graph. We also prove that the problem admits a polynomial kernel when parameterized by the vertex-deletion distance to a pseudo forest, a graph in which every connected component has at most one cycle. In contrast, we prove that a slightly smaller parameterization does not allow for a polynomial kernel unless NP coNP=poly and the polynomial-time hierarchy collapses.
