群落构建机制研究是生态学研究的热点。长白山自然保护区拥有完整的原始阔叶红松林生态系统,近年来随着物种多样性丧失愈发严重,对该地区开展群落构建机制研究显得尤为重要。该研究以长白山不同演替阶段的3块5.2hm^2固定监测样地(次生...群落构建机制研究是生态学研究的热点。长白山自然保护区拥有完整的原始阔叶红松林生态系统,近年来随着物种多样性丧失愈发严重,对该地区开展群落构建机制研究显得尤为重要。该研究以长白山不同演替阶段的3块5.2hm^2固定监测样地(次生杨桦林、次生针阔混交林、原始椴树红松林)为研究对象,通过采集样地内主要树种的6个关键功能性状(叶面积、比叶面积、叶片厚度、叶氮含量、叶磷含量、最大树高),分析不同空间尺度下(5 m×5 m, 10 m×10 m, 20 m×20 m, 30 m×30m, 40 m×40 m, 50 m×50 m和60 m×60 m)及不同演替阶段群落性状空间值的变化,结合零模型的模拟结果对长白山温带森林演替过程中的群落构建机制进行讨论。结果表明:种库大小对于研究结果具有重要影响。在较大的种库下,环境过滤作用影响显著。而在样地水平进行研究时,演替早期和中期,群落性状空间值与零模型模拟值无显著差异,在演替的晚期,群落性状空间值显著高于零模型模拟值。结合多个群落功能多样性指数分析发现,环境过滤和竞争作用共同决定该地区顶级群落的物种组成。在演替早期大量物种迁入,群落内物种间存在强烈的资源竞争,而随着演替进行,部分物种逐渐被竞争排除出群落,群落中的物种呈现明显的生态位分化,竞争作用是维持物种共存的主要机制。展开更多
A design and verification of linear state observers which estimate state information such as angular velocity and load torque for retraction control of the motorized seat belt (MSB) system were described. The motorize...A design and verification of linear state observers which estimate state information such as angular velocity and load torque for retraction control of the motorized seat belt (MSB) system were described. The motorized seat belt system provides functions to protect passengers and improve passenger's convenience. Each MSB function has its own required belt tension which is determined by the function's purpose. To realize the MSB functions, state information, such as seat belt winding velocity and seat belt tension are required. Using a linear state observer, the state information for MSB operations can be estimated without sensors. To design the linear state observer, the motorized seat belt system is analyzed and represented as a state space model which contains load torque as an augmented state. Based on the state space model, a linear state observer was designed and verified by experiments. Also, the retraction control of the MSB algorithm using linear state observer was designed and verified on the test bench. With the designed retraction control algorithm using the linear state observer, it is possible to realize various types of MSB functions.展开更多
Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is d...Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is derived from the basic equations of elasticity based on the state space concept. Then, the differential quadrature (DQ) technique is introduced to discretize the longitu- dinal domain of the plate so that a series of ordinary differential state equations are obtained at the discrete points. Meanwhile, the edge constrained conditions are handled directly using the stress and displacement components without the Saint-Venant principle. The thickness domain is solved analytically based on the state space formalism along with the continuity conditions at interfaces. The present method is validated by comparing the results to the exact solutions of Pagano’s problem. Numerical results for fully clamped thick laminates are presented, and the influences of ply angle on stress distributions are discussed.展开更多
State estimation of biological process variables directly influences the performance of on-line monitoring and op- timal control for fermentation process. A novel nonlinear state estimation method for fermentation pro...State estimation of biological process variables directly influences the performance of on-line monitoring and op- timal control for fermentation process. A novel nonlinear state estimation method for fermentation process is proposed using cubature Kalman filter （CKF） to incorporate delayed measurements. The square-root version of CI（F （SCKF） algorithm is given and the system with delayed measurements is described. On this basis, the sample-state augmentation method for the SCKF algorithm is provided and the implementation of the proposed algorithm is constructed. Then a nonlinear state space model for fermentation process is established and the SCKF algorithm incorporating delayed measurements based on fermentation process model is presented to implement the nonlinear state estimation. Finally, the proposed nonlinear state estimation methodology is applied to the state estimation for penicillin and industrial yeast fermentation processes. The simulation results show that the on-fine state estimation for fermentation process can be achieved by the proposed method with higher esti- mation accuracy and better stability.展开更多
To combat the well-known state-space explosion problem in Prop ositional Linear T emp o- ral Logic （PLTL） model checking, a novel algo- rithm capable of translating PLTL formulas into Nondeterministic Automata （NA...To combat the well-known state-space explosion problem in Prop ositional Linear T emp o- ral Logic （PLTL） model checking, a novel algo- rithm capable of translating PLTL formulas into Nondeterministic Automata （NA） in an efficient way is proposed. The algorithm firstly transforms PLTL formulas into their non-free forms, then it further translates the non-free formulas into their Normal Forms （NFs）, next constructs Normal Form Graphs （NFGs） for NF formulas, and it fi- nally transforms NFGs into the NA which ac- cepts both finite words and int-mite words. The experimental data show that the new algorithm re- duces the average number of nodes of target NA for a benchmark formula set and selected formulas in the literature, respectively. These results indi- cate that the PLTL model checking technique em- ploying the new algorithm generates a smaller state space in verification of concurrent systems.展开更多
文摘群落构建机制研究是生态学研究的热点。长白山自然保护区拥有完整的原始阔叶红松林生态系统,近年来随着物种多样性丧失愈发严重,对该地区开展群落构建机制研究显得尤为重要。该研究以长白山不同演替阶段的3块5.2hm^2固定监测样地(次生杨桦林、次生针阔混交林、原始椴树红松林)为研究对象,通过采集样地内主要树种的6个关键功能性状(叶面积、比叶面积、叶片厚度、叶氮含量、叶磷含量、最大树高),分析不同空间尺度下(5 m×5 m, 10 m×10 m, 20 m×20 m, 30 m×30m, 40 m×40 m, 50 m×50 m和60 m×60 m)及不同演替阶段群落性状空间值的变化,结合零模型的模拟结果对长白山温带森林演替过程中的群落构建机制进行讨论。结果表明:种库大小对于研究结果具有重要影响。在较大的种库下,环境过滤作用影响显著。而在样地水平进行研究时,演替早期和中期,群落性状空间值与零模型模拟值无显著差异,在演替的晚期,群落性状空间值显著高于零模型模拟值。结合多个群落功能多样性指数分析发现,环境过滤和竞争作用共同决定该地区顶级群落的物种组成。在演替早期大量物种迁入,群落内物种间存在强烈的资源竞争,而随着演替进行,部分物种逐渐被竞争排除出群落,群落中的物种呈现明显的生态位分化,竞争作用是维持物种共存的主要机制。
基金Project supported by the Second Stage of Brain Korea 21 Projects and Changwon National University in 2011-2012
文摘A design and verification of linear state observers which estimate state information such as angular velocity and load torque for retraction control of the motorized seat belt (MSB) system were described. The motorized seat belt system provides functions to protect passengers and improve passenger's convenience. Each MSB function has its own required belt tension which is determined by the function's purpose. To realize the MSB functions, state information, such as seat belt winding velocity and seat belt tension are required. Using a linear state observer, the state information for MSB operations can be estimated without sensors. To design the linear state observer, the motorized seat belt system is analyzed and represented as a state space model which contains load torque as an augmented state. Based on the state space model, a linear state observer was designed and verified by experiments. Also, the retraction control of the MSB algorithm using linear state observer was designed and verified on the test bench. With the designed retraction control algorithm using the linear state observer, it is possible to realize various types of MSB functions.
基金Project supported by the National Natural Science Foundation of China (No. 10432030)the China Postdoctoral Science Foundation (No. 20060401071)the Program for New Century Excellent Talent in University of China (No. NCET-05-0510)
文摘Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is derived from the basic equations of elasticity based on the state space concept. Then, the differential quadrature (DQ) technique is introduced to discretize the longitu- dinal domain of the plate so that a series of ordinary differential state equations are obtained at the discrete points. Meanwhile, the edge constrained conditions are handled directly using the stress and displacement components without the Saint-Venant principle. The thickness domain is solved analytically based on the state space formalism along with the continuity conditions at interfaces. The present method is validated by comparing the results to the exact solutions of Pagano’s problem. Numerical results for fully clamped thick laminates are presented, and the influences of ply angle on stress distributions are discussed.
基金Supported by the National Natural Science Foundation of China(61503019)the Beijing Natural Science Foundation(4152041)Beijing Higher Education Young Elite Teacher Project(YETP0504)
文摘State estimation of biological process variables directly influences the performance of on-line monitoring and op- timal control for fermentation process. A novel nonlinear state estimation method for fermentation process is proposed using cubature Kalman filter （CKF） to incorporate delayed measurements. The square-root version of CI（F （SCKF） algorithm is given and the system with delayed measurements is described. On this basis, the sample-state augmentation method for the SCKF algorithm is provided and the implementation of the proposed algorithm is constructed. Then a nonlinear state space model for fermentation process is established and the SCKF algorithm incorporating delayed measurements based on fermentation process model is presented to implement the nonlinear state estimation. Finally, the proposed nonlinear state estimation methodology is applied to the state estimation for penicillin and industrial yeast fermentation processes. The simulation results show that the on-fine state estimation for fermentation process can be achieved by the proposed method with higher esti- mation accuracy and better stability.
基金The first author of this paper would like to thank the follow- ing scholars, Prof. Joseph Sifakis, 2007 Turing Award Winner, for his invaluable help with my research and Dr. Kevin Lu at Brunel University, UK for his excellent suggestions on this paper. This work was supported by the National Natural Sci- ence Foundation of China under Grant No.61003079 the Chi- na Postdoctoral Science Foundation under Grant No. 2012M511588.
文摘To combat the well-known state-space explosion problem in Prop ositional Linear T emp o- ral Logic （PLTL） model checking, a novel algo- rithm capable of translating PLTL formulas into Nondeterministic Automata （NA） in an efficient way is proposed. The algorithm firstly transforms PLTL formulas into their non-free forms, then it further translates the non-free formulas into their Normal Forms （NFs）, next constructs Normal Form Graphs （NFGs） for NF formulas, and it fi- nally transforms NFGs into the NA which ac- cepts both finite words and int-mite words. The experimental data show that the new algorithm re- duces the average number of nodes of target NA for a benchmark formula set and selected formulas in the literature, respectively. These results indi- cate that the PLTL model checking technique em- ploying the new algorithm generates a smaller state space in verification of concurrent systems.
