Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this pro...Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.展开更多
Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the ...Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the integrate method to the continuous model. And the discrete model was transformed to the form with two linear subsystems through coordinate transformation. Two feedback control laws, time-invariant control law and time-varying control law, were proposed; and the local stabilization and global stabilization were realized respectively. The simulation results show the effectiveness of the proposed control laws. The discrete nonholonomic chained system can converge to zero from any initial state exponentially, and the convergence rate can be changed through changing the parameters of the control laws.展开更多
Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen ...Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen consumption during the China's urbanization process.Results showed that after 1980s,the annual consumption of Chinese urban residents' food-nitrogen had a change trend of " increase-decrease-increase" and generally presented as a slight increasing trend;With the acceleration of rapid economic development and urbanization process,Chinese urban residents' food-nitrogen consumption will still keep a rising trend in future,and also has a large rising space.展开更多
Aim To study the effects of tetrodotoxin (TTX) combined with acetylsalicylic acid (ASA) on nociceptive stimulus in mice. Methods To assess the antinociceptive effects of TTX, ASA or TTX plus ASA, the acetic acid-i...Aim To study the effects of tetrodotoxin (TTX) combined with acetylsalicylic acid (ASA) on nociceptive stimulus in mice. Methods To assess the antinociceptive effects of TTX, ASA or TTX plus ASA, the acetic acid-induced abdominal constriction test and formalin pain test were used. Results TTX (0.5 - 4.0 μg· kg^-1 ) or ASA (25 - 200 mg· kg^-1 ) im produced a significant inhibition of acetic acid-induced abdominal constriction. The median inhibitory doses (ID508) were 2.1 μg· kg^-1 for TTX( and 64 mg· kg^-1 for ASA. TTX and ASA also showed a dose-dependent inhibition of the second phase response in the formalin pain model, the ID508, being 2.3μg·kg^-1 and 74.2 mg· kg^-1, respectively. The ihteraction between TTX and ASA was synergistic, as evidenced by the fact that (1) when ASA alone compared with the combination of TTX (0.79 μg · kg^-1 or 0.39μg· kg^-1 ) and ASA, the ID508, of ASA reduced from 64.0 mg· kg^-1 to 5.8 mg· kg^-1 or 12.6 mg· kg^-1, and from 74.2 mg· kg^-1 to 7.4 mg· kg^-1 or 13.0 mg· kg^-1 on tile two models of nociceptive tests, respectively; and that (2) synergism in the analgesic effects was shown by isobiolographic analysis. Conclusion TTX, ASA and the combination of the two drags produce analgesic effects in acetic acid-induced abdominal constriction test and formalin-induced pain test. The interactions between TTX and ASA may be useful in developing novel analgesic agents.展开更多
The exponential stabilization problem for finite dimensional switched systems is extended to the infinite dimensional distributed parameter systems in the Hilbert space. Based on the semigroup theory, by applying the ...The exponential stabilization problem for finite dimensional switched systems is extended to the infinite dimensional distributed parameter systems in the Hilbert space. Based on the semigroup theory, by applying the multiple Lyapunov function method, the exponential stabilization conditions are derived. These conditions are given in the form of linear operator inequalities where the decision variables are operators in the Hilbert space; while the stabilization properties depend on the switching rule. Being applied to the two-dimensional heat switched propagation equations with the Dirichlet boundary conditions, these linear operator inequalities are transformed into standard linear matrix inequalities. Finally, two examples are given to illustrate the effectiveness of the proposed results.展开更多
From the viewpoint of Graph Theory this paper builds a town road network graph of regional scale, and proposes numerical vertex degree (Di), rank vertex degree (Dr) and population size vertex degree (Dp) on the ...From the viewpoint of Graph Theory this paper builds a town road network graph of regional scale, and proposes numerical vertex degree (Di), rank vertex degree (Dr) and population size vertex degree (Dp) on the base of vertex degree (D). Then the indicators of Di, Dr, Op and mathematical statistics methods are applied to investigating scale-free structure of town road networks in the southern Jiangsu Province. The results show that the distribution of Oi does not exhibit scale-free properties, but Dr and Dp do. Additionally the correlation coefficient between Dp and Di is only 0.569, but the spatial correlation between Dp and Dr is very evident on the base of correlation analysis and spatial analysis of GIS. The mutual mechanism between Dp and Dr spatially represents a "Core-Belt" model of town development of regional scale. The town development model is open and clustered, and beneficial to both economic development and ecological protection. And then we suggest that Suzhou City, Wuxi City, Changzhou City and Wujin City control towns' high-density pattern by conducting centralization and consolidation policies, and properly controlling and planning higher rank roads; whereas Nanjing City, Zhenjiang City, Jintan City and Liyang City must strengthen the development of towns along higher rank roads.展开更多
In this paper, we identify the geographic information systems (GIS), discuss the components of GIS, which integrates five essential components: hardware, software, data, people, and methods. Present the relations betw...In this paper, we identify the geographic information systems (GIS), discuss the components of GIS, which integrates five essential components: hardware, software, data, people, and methods. Present the relations between computer and urban planning, urban planning and GIS. Moreover, the main discussion on a case study that explores the possibility of using ArcView GIS software to assemble, store, manipulate, and analyze historic site- Xinjin ferry district in Zhenjiang.展开更多
Let P(s, δ) be a sphere plant family described by the transfer function set where the coefficients of the denominator and numerator polynomials are affine in a real uncertain parameter vector δ satisfying the Eucl...Let P(s, δ) be a sphere plant family described by the transfer function set where the coefficients of the denominator and numerator polynomials are affine in a real uncertain parameter vector δ satisfying the Euclidean norm constraint ||δ||〈δ. The concept of stabilizability radius of P(s, δ) is introduced which is the norm bound δs for δ such that every member plant of P(s, δ) is stabilizable if and only if ||δ||〈δs. The stabilizability radius can be simply interpreted as the 'largest sphere' around the nominal plant P(s,θ) such that P(s, δ) is stabilizable. The numerical method and the analytical method are presented to solve the stabilizability radius calculation problem of the sphere plants.展开更多
A two-staged electronic ballast with wide dimming range, high power factor(PF) and low electromagnetic interference(EMI) is presented. It changes the input voltage of the stage of power inverter for dimming control, s...A two-staged electronic ballast with wide dimming range, high power factor(PF) and low electromagnetic interference(EMI) is presented. It changes the input voltage of the stage of power inverter for dimming control, so it overcomes some limitations of traditional electronic ballasts that use frequency variation. At the same time, the stage of power inverter runs under the soft-switching at the fixed switching frequency and reduces EMI greatly. Its principle and characteristic are analyzed in detail,and experimental and simulated results are obtained on a 40 W fluorescent lamp.展开更多
This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption de...This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously.展开更多
This paper responds to criticisms levied at my previous research paper on "gray" household income in China. In 2010, I published a paper estimating the actual income of high-income urban residents in China. Results ...This paper responds to criticisms levied at my previous research paper on "gray" household income in China. In 2010, I published a paper estimating the actual income of high-income urban residents in China. Results indicated that per-capita disposable income for the wealthiest 10 percent of households in 2008 was roughly 139,000 yuan, rather than the 44,000 yuan indicated by official statistics. This suggested an aggregate gray income of 9.3 trillion yuan for China "s urban residents in 2008, mainly dispersed among high income groups. In 2012, Luo Chuliang et al. published a criticism paper, arguing that flawed methodology and analysis exaggerated gray income and household income gaps. This paper both responds to these criticisms and reasserts my original claim that official statistics seriously underestimate both gray income and income inequality in China.展开更多
An impulsive control scheme of Liu's system is presented in this paper. Some less conservative conditions with impulses at fixed times are provided, which can guarantee the global asymptotical stability and global ex...An impulsive control scheme of Liu's system is presented in this paper. Some less conservative conditions with impulses at fixed times are provided, which can guarantee the global asymptotical stability and global exponential stability for the impulsive control of Liu's systems. We also present the estimate of the stable region for the equidistance impulsive interval. Furthermore, an illustrative example is given to show the effectiveness of the proposed results.展开更多
This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer an...This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communi- cation channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.展开更多
Using data for China for the years 1991 to 2005 by province and employing the semi- parametric panel data model estimation method developed by Horowitz (2004) and Henderson et al. (2006) and Hubler's non-parametr...Using data for China for the years 1991 to 2005 by province and employing the semi- parametric panel data model estimation method developed by Horowitz (2004) and Henderson et al. (2006) and Hubler's non-parametric generalized method of moments (GMM) estimation (2005), this article constructs a dynamic semi-parametric panel data model and describes the dynamic changing trajectory of the effect on consumption of income disparity among urban residents. Our findings show that there is a significant "ratchet effect" in the consumption of urban residents; that income disparity among urban residents has a clear negative influence on consumption; and that the trajectory of this influence shows a roughly bimodal curve.展开更多
The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain ...The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain a new uncertain model of the nonholonomic kinematic system in the image plane, which is a chained form with uncalibrated visual parameters, from the camera robotic system. A new time varying feedback controller is proposed for the exponential stabilization of the nonholonomic chained system with unknown parameters by using state-scaling and switching technique. The exponential stability of the closed loop system is rigorously proved. Simulation results demonstrate the effectiveness of the proposed methods.展开更多
This paper deals with the problem of the stabilization for multi-input polytopic nonlinear systems. Based on the robust control Lyapunov function, a sufficient condition for the existence of time-invariant, continuous...This paper deals with the problem of the stabilization for multi-input polytopic nonlinear systems. Based on the robust control Lyapunov function, a sufficient condition for the existence of time-invariant, continuous, asymptotically stabilizing state feedback controller is derived. It is shown that the obtained sufficient condition is also necessary if there exists a state feedback controller such that the closed-loop system has a robust Lyapunov function for all possible uncertainties. Moreover, a universal formula for constructing stabilizing controller is proposed and the existence of the corresponding Lyapunov function is proven. Particularly, a Lyapunov function is constructed for the polytopic nonlinear system in canonical form. Finally, the feasibility of the proposed control law is verified by a numerical example.展开更多
Objective: Transcatheter aortic valve implantation (TAVI) is a minimally invasive therapy for elderly patients with severe aortic valve stenosis who were refused surgical aortic valve replacement because of the hig...Objective: Transcatheter aortic valve implantation (TAVI) is a minimally invasive therapy for elderly patients with severe aortic valve stenosis who were refused surgical aortic valve replacement because of the high perioperative risk. Traditionally, this procedure has been done under general anesthesia, but more recently local anesthesia and sedation have become popular. This research assessed the effectiveness of transfemoral TAVI under bispectral index (BIS)-guided sedation. Methods: In this single-center retrospective control analysis, clinical data, including demographic characteristics, echocardiography, periprocedural data, and main complications, were collected and assessed in 113 patients undergoing TAVI through the femoral artery under general anesthesia (GA group, n=36) and under BIS-guided sedation (SED group, n=77). Results: The demographic characteristics and echocardi-ographic parameters between the two groups were similar (P〉0.05). Two (2.6%) of patients were moved from BIS-guided sedation to general anesthesia for surgical reasons. Procedures were significantly shorter in the SED group than in the GA group ((127.10±44.43) min vs. (165.90±71.62) min, P=0.004). Patients in the SED group lost less blood and received significantly fewer red blood cells and catecholamines than those in the GA group (5.19% vs. 22.22%, P=0.017 and 67.53% vs. 97.22%, P〈0.001). The length of hospital stay was significantly shorter and there were fewer pulmonary complications in the SED group than in the GA group. Thirty-day mortality was similar between the two groups. Conclusions: BIS-guided sedation is a feasible and safe approach for transfemoral TAVl. The anes- thesiologist should choose the best anesthetic method according to the team's experience.展开更多
The authors consider the problem of boundary feedback stabilization of the 1D Euler gas dynamics locally around stationary states and prove the exponential stability with respect to the H2-norm. To this end, an explic...The authors consider the problem of boundary feedback stabilization of the 1D Euler gas dynamics locally around stationary states and prove the exponential stability with respect to the H2-norm. To this end, an explicit Lyapunov function as a weighted and squared H2-norm of a small perturbation of the stationary solution is constructed. The authors show that by a suitable choice of the boundary feedback conditions, the H2- exponential stability of the stationary solution follows. Due to this fact, the system is stabilized over an infinite time interval. Furthermore, exponential estimates for the C norm are derived.展开更多
We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed ...We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed at the input terminal of the quantizer,and another zoomer is located at the output terminal of the quantizer.The zoomers possess a common adjustable time-varying parameter.By using the adaptive laws for the time-varying parameter and estimating boundary error of values of quantization,the stabilization feedback controller with the quantized state measurements is proposed for a class of chaotic systems.Finally,some numerical examples are given to demonstrate the validity of the proposed methods.展开更多
文摘Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.
文摘Aimed at the stabilization of the nonholonomic chained system under fixed sample control, two control laws were proposed. The discrete model of the nonholonomic chained system under zero-hold was obtained through the integrate method to the continuous model. And the discrete model was transformed to the form with two linear subsystems through coordinate transformation. Two feedback control laws, time-invariant control law and time-varying control law, were proposed; and the local stabilization and global stabilization were realized respectively. The simulation results show the effectiveness of the proposed control laws. The discrete nonholonomic chained system can converge to zero from any initial state exponentially, and the convergence rate can be changed through changing the parameters of the control laws.
基金Supported by State Council Special Fund for Pollution Sources Survey (WPXC2007C200)~~
文摘Change trend of Chinese urban residents' per capita food-nitrogen annual consumption from 1981 to 2007 was analyzed and predicted by using ARIMA time-series model in order to reveal the change of urban food-nitrogen consumption during the China's urbanization process.Results showed that after 1980s,the annual consumption of Chinese urban residents' food-nitrogen had a change trend of " increase-decrease-increase" and generally presented as a slight increasing trend;With the acceleration of rapid economic development and urbanization process,Chinese urban residents' food-nitrogen consumption will still keep a rising trend in future,and also has a large rising space.
文摘Aim To study the effects of tetrodotoxin (TTX) combined with acetylsalicylic acid (ASA) on nociceptive stimulus in mice. Methods To assess the antinociceptive effects of TTX, ASA or TTX plus ASA, the acetic acid-induced abdominal constriction test and formalin pain test were used. Results TTX (0.5 - 4.0 μg· kg^-1 ) or ASA (25 - 200 mg· kg^-1 ) im produced a significant inhibition of acetic acid-induced abdominal constriction. The median inhibitory doses (ID508) were 2.1 μg· kg^-1 for TTX( and 64 mg· kg^-1 for ASA. TTX and ASA also showed a dose-dependent inhibition of the second phase response in the formalin pain model, the ID508, being 2.3μg·kg^-1 and 74.2 mg· kg^-1, respectively. The ihteraction between TTX and ASA was synergistic, as evidenced by the fact that (1) when ASA alone compared with the combination of TTX (0.79 μg · kg^-1 or 0.39μg· kg^-1 ) and ASA, the ID508, of ASA reduced from 64.0 mg· kg^-1 to 5.8 mg· kg^-1 or 12.6 mg· kg^-1, and from 74.2 mg· kg^-1 to 7.4 mg· kg^-1 or 13.0 mg· kg^-1 on tile two models of nociceptive tests, respectively; and that (2) synergism in the analgesic effects was shown by isobiolographic analysis. Conclusion TTX, ASA and the combination of the two drags produce analgesic effects in acetic acid-induced abdominal constriction test and formalin-induced pain test. The interactions between TTX and ASA may be useful in developing novel analgesic agents.
基金The National Natural Science Foundation of China(No.61273119,61104068,61374038)the Natural Science Foundation of Jiangsu Province(No.BK2011253)
文摘The exponential stabilization problem for finite dimensional switched systems is extended to the infinite dimensional distributed parameter systems in the Hilbert space. Based on the semigroup theory, by applying the multiple Lyapunov function method, the exponential stabilization conditions are derived. These conditions are given in the form of linear operator inequalities where the decision variables are operators in the Hilbert space; while the stabilization properties depend on the switching rule. Being applied to the two-dimensional heat switched propagation equations with the Dirichlet boundary conditions, these linear operator inequalities are transformed into standard linear matrix inequalities. Finally, two examples are given to illustrate the effectiveness of the proposed results.
基金Under the auspices of National Natural Science Foundation of China (No. 40435013, No. 40535026)
文摘From the viewpoint of Graph Theory this paper builds a town road network graph of regional scale, and proposes numerical vertex degree (Di), rank vertex degree (Dr) and population size vertex degree (Dp) on the base of vertex degree (D). Then the indicators of Di, Dr, Op and mathematical statistics methods are applied to investigating scale-free structure of town road networks in the southern Jiangsu Province. The results show that the distribution of Oi does not exhibit scale-free properties, but Dr and Dp do. Additionally the correlation coefficient between Dp and Di is only 0.569, but the spatial correlation between Dp and Dr is very evident on the base of correlation analysis and spatial analysis of GIS. The mutual mechanism between Dp and Dr spatially represents a "Core-Belt" model of town development of regional scale. The town development model is open and clustered, and beneficial to both economic development and ecological protection. And then we suggest that Suzhou City, Wuxi City, Changzhou City and Wujin City control towns' high-density pattern by conducting centralization and consolidation policies, and properly controlling and planning higher rank roads; whereas Nanjing City, Zhenjiang City, Jintan City and Liyang City must strengthen the development of towns along higher rank roads.
文摘In this paper, we identify the geographic information systems (GIS), discuss the components of GIS, which integrates five essential components: hardware, software, data, people, and methods. Present the relations between computer and urban planning, urban planning and GIS. Moreover, the main discussion on a case study that explores the possibility of using ArcView GIS software to assemble, store, manipulate, and analyze historic site- Xinjin ferry district in Zhenjiang.
基金Project(JSPS.KAKENHI22560451) supported by the Japan Society for the Promotion of ScienceProject(69904003) supported by the National Natural Science Foundation of ChinaProject(YJ0267016) supported by the Advanced Ordnance Research Supporting Fund of China
文摘Let P(s, δ) be a sphere plant family described by the transfer function set where the coefficients of the denominator and numerator polynomials are affine in a real uncertain parameter vector δ satisfying the Euclidean norm constraint ||δ||〈δ. The concept of stabilizability radius of P(s, δ) is introduced which is the norm bound δs for δ such that every member plant of P(s, δ) is stabilizable if and only if ||δ||〈δs. The stabilizability radius can be simply interpreted as the 'largest sphere' around the nominal plant P(s,θ) such that P(s, δ) is stabilizable. The numerical method and the analytical method are presented to solve the stabilizability radius calculation problem of the sphere plants.
文摘A two-staged electronic ballast with wide dimming range, high power factor(PF) and low electromagnetic interference(EMI) is presented. It changes the input voltage of the stage of power inverter for dimming control, so it overcomes some limitations of traditional electronic ballasts that use frequency variation. At the same time, the stage of power inverter runs under the soft-switching at the fixed switching frequency and reduces EMI greatly. Its principle and characteristic are analyzed in detail,and experimental and simulated results are obtained on a 40 W fluorescent lamp.
文摘This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously.
文摘This paper responds to criticisms levied at my previous research paper on "gray" household income in China. In 2010, I published a paper estimating the actual income of high-income urban residents in China. Results indicated that per-capita disposable income for the wealthiest 10 percent of households in 2008 was roughly 139,000 yuan, rather than the 44,000 yuan indicated by official statistics. This suggested an aggregate gray income of 9.3 trillion yuan for China "s urban residents in 2008, mainly dispersed among high income groups. In 2012, Luo Chuliang et al. published a criticism paper, arguing that flawed methodology and analysis exaggerated gray income and household income gaps. This paper both responds to these criticisms and reasserts my original claim that official statistics seriously underestimate both gray income and income inequality in China.
基金Supported by Foundation of Zhejiang Educational Committee under Grant No. Y200805720
文摘An impulsive control scheme of Liu's system is presented in this paper. Some less conservative conditions with impulses at fixed times are provided, which can guarantee the global asymptotical stability and global exponential stability for the impulsive control of Liu's systems. We also present the estimate of the stable region for the equidistance impulsive interval. Furthermore, an illustrative example is given to show the effectiveness of the proposed results.
文摘This paper addresses a robust stabilization problem of a class of uncertain nonlinear systems using output measurements via a finite data-rate communication channel. The authors assumes that there exist an observer and a control law for the systems in the absence of any finite data-rate communi- cation channel. Based on the observer and the control law, the authors constructs an encoder/decoder pair and provides a sufficient condition, including suitable sampling period and data rate, which will guarantee the stability of the closed-loop systems when a finite data-rate communication channel is introduced.
文摘Using data for China for the years 1991 to 2005 by province and employing the semi- parametric panel data model estimation method developed by Horowitz (2004) and Henderson et al. (2006) and Hubler's non-parametric generalized method of moments (GMM) estimation (2005), this article constructs a dynamic semi-parametric panel data model and describes the dynamic changing trajectory of the effect on consumption of income disparity among urban residents. Our findings show that there is a significant "ratchet effect" in the consumption of urban residents; that income disparity among urban residents has a clear negative influence on consumption; and that the trajectory of this influence shows a roughly bimodal curve.
基金supported by the National Science Foundation under Grant No.60874002Key Project of Shanghai Education Committee under Grant No.09ZZ158+1 种基金Key Discipline of Shanghai under Grant No.S30501Doctoral Fund of Shandong University of Technology under Grant No.411016
文摘The visual serving stabilization for a kind of nonholonomic mobile robots with uncalibrated camera parameters is investigated based on the visual feedback and the state and input transforma- tions. The authors obtain a new uncertain model of the nonholonomic kinematic system in the image plane, which is a chained form with uncalibrated visual parameters, from the camera robotic system. A new time varying feedback controller is proposed for the exponential stabilization of the nonholonomic chained system with unknown parameters by using state-scaling and switching technique. The exponential stability of the closed loop system is rigorously proved. Simulation results demonstrate the effectiveness of the proposed methods.
文摘This paper deals with the problem of the stabilization for multi-input polytopic nonlinear systems. Based on the robust control Lyapunov function, a sufficient condition for the existence of time-invariant, continuous, asymptotically stabilizing state feedback controller is derived. It is shown that the obtained sufficient condition is also necessary if there exists a state feedback controller such that the closed-loop system has a robust Lyapunov function for all possible uncertainties. Moreover, a universal formula for constructing stabilizing controller is proposed and the existence of the corresponding Lyapunov function is proven. Particularly, a Lyapunov function is constructed for the polytopic nonlinear system in canonical form. Finally, the feasibility of the proposed control law is verified by a numerical example.
文摘Objective: Transcatheter aortic valve implantation (TAVI) is a minimally invasive therapy for elderly patients with severe aortic valve stenosis who were refused surgical aortic valve replacement because of the high perioperative risk. Traditionally, this procedure has been done under general anesthesia, but more recently local anesthesia and sedation have become popular. This research assessed the effectiveness of transfemoral TAVI under bispectral index (BIS)-guided sedation. Methods: In this single-center retrospective control analysis, clinical data, including demographic characteristics, echocardiography, periprocedural data, and main complications, were collected and assessed in 113 patients undergoing TAVI through the femoral artery under general anesthesia (GA group, n=36) and under BIS-guided sedation (SED group, n=77). Results: The demographic characteristics and echocardi-ographic parameters between the two groups were similar (P〉0.05). Two (2.6%) of patients were moved from BIS-guided sedation to general anesthesia for surgical reasons. Procedures were significantly shorter in the SED group than in the GA group ((127.10±44.43) min vs. (165.90±71.62) min, P=0.004). Patients in the SED group lost less blood and received significantly fewer red blood cells and catecholamines than those in the GA group (5.19% vs. 22.22%, P=0.017 and 67.53% vs. 97.22%, P〈0.001). The length of hospital stay was significantly shorter and there were fewer pulmonary complications in the SED group than in the GA group. Thirty-day mortality was similar between the two groups. Conclusions: BIS-guided sedation is a feasible and safe approach for transfemoral TAVl. The anes- thesiologist should choose the best anesthetic method according to the team's experience.
基金Project supported by the Initial Training Network "FIRST" of the Seventh Framework Programme of the European Community’s (No. 238702) the DFG-Priority Program 1253: Optimization with PDEs (No. GU 376/7-1)
文摘The authors consider the problem of boundary feedback stabilization of the 1D Euler gas dynamics locally around stationary states and prove the exponential stability with respect to the H2-norm. To this end, an explicit Lyapunov function as a weighted and squared H2-norm of a small perturbation of the stationary solution is constructed. The authors show that by a suitable choice of the boundary feedback conditions, the H2- exponential stability of the stationary solution follows. Due to this fact, the system is stabilized over an infinite time interval. Furthermore, exponential estimates for the C norm are derived.
基金Supported by the National Science Foundation of China under Grant No.11172017the Guangdong Natural Science Foundation under Grant No.8151009001000061Natural Science Joint Research Program Foundation of Guangdong Province under Grant No.8351009001000002
文摘We investigate asymptotical stabilization for a class of chaotic systems by means of quantization measurements of states.The quantizer adopted in this paper takes finite many values.In particular,one zoomer is placed at the input terminal of the quantizer,and another zoomer is located at the output terminal of the quantizer.The zoomers possess a common adjustable time-varying parameter.By using the adaptive laws for the time-varying parameter and estimating boundary error of values of quantization,the stabilization feedback controller with the quantized state measurements is proposed for a class of chaotic systems.Finally,some numerical examples are given to demonstrate the validity of the proposed methods.