Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achi...Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achieve rapid,optically sectioned,SR observation with hundreds to thousands of time points.However,real-time observation is still out of reach for most SIM setups as conventional algorithms for image reconstruction involve a heavy computing burden.To address this limitation,an accelerated reconstruction algorithm was developed by implementing a simplified workflow for SR-SIM,termed joint space and frequency reconstruction.This algorithm results in an 80-fold improvement in reconstruction speed relative to the widely used Wiener-SIM.Critically,the increased processing speed does not come at the expense of spatial resolution or sectioning capability,as demonstrated by live imaging of microtubule dynamics and mitochondrial tubulation.展开更多
Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted...Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.展开更多
Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are scarce.In this study,the switching and periodic soliton explosion processes of...Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are scarce.In this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are realized.The generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three wavelengths.Positive and negative dispersion lead to different group velocities of solitons.The presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an explosion.With an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental results.This work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.展开更多
The automatic detection and identification of electroencephalogram waves play an important role in the prediction, diagnosis and treatment of epileptic seizures. In this study, a nonlinear dynamics index–approximate ...The automatic detection and identification of electroencephalogram waves play an important role in the prediction, diagnosis and treatment of epileptic seizures. In this study, a nonlinear dynamics index–approximate entropy and a support vector machine that has strong generalization ability were applied to classify electroencephalogram signals at epileptic interictal and ictal periods. Our aim was to verify whether approximate entropy waves can be effectively applied to the automatic real-time detection of epilepsy in the electroencephalogram, and to explore its generalization ability as a classifier trained using a nonlinear dynamics index. Four patients presenting with partial epileptic seizures were included in this study. They were all diagnosed with neocortex localized epilepsy and epileptic foci were clearly observed by electroencephalogram. The electroencephalogram data form the four involved patients were segmented and the characteristic values of each segment, that is, the approximate entropy, were extracted. The support vector machine classifier was constructed with the approximate entropy extracted from one epileptic case, and then electroencephalogram waves of the other three cases were classified, reaching a 93.33% accuracy rate. Our findings suggest that the use of approximate entropy allows the automatic real-time detection of electroencephalogram data in epileptic cases. The combination of approximate entropy and support vector machines shows good generalization ability for the classification of electroencephalogram signals for epilepsy.展开更多
Quantum dynamics calculations for the title reaction H（2S） ＋ S2（X3∑g） → SH（X2П） ＋S（3P） are performed byusing a globally accurate double many-body expansion potential energy surface [J. Phys. Chem. A 115 5...Quantum dynamics calculations for the title reaction H（2S） ＋ S2（X3∑g） → SH（X2П） ＋S（3P） are performed byusing a globally accurate double many-body expansion potential energy surface [J. Phys. Chem. A 115 5274 （2011）]. The Chebyshev real wave packet propagation method is employed to obtain the dynamical information, such as reaction probability, initial state-specified integral cross section, and thermal rate constant. It is found not only that there is a reaction threshold near 0.7 eV in both reaction probabilities and integral cross section curves, but also that both the probability and cross section increase firstly and then decrease as the collision energy increases. The existence of the resonance structure in both the probability and cross section curves is ascribed to the deep potential well. The calculation of the rate constant reveals that the reaction occurring on the potential energy surface of the ground-state HS2 is slow to take place.展开更多
Monitoring and early warning is an important means to effectively prevent risks in agricultural production,consumption and price.In particular,with the change of modes of national administration against the background...Monitoring and early warning is an important means to effectively prevent risks in agricultural production,consumption and price.In particular,with the change of modes of national administration against the background of big data,improving the capacity to monitor agricultural products is of great significance for macroeconomic decision-making.Agricultural product information early warning thresholds are the core of agricultural product monitoring and early warning.How to appropriately determine the early warning thresholds of multi-temporal agricultural product information is a key question to realize real-time and dynamic monitoring and early warning.Based on the theory of abnormal fluctuation of agricultural product information and the research of substantive impact on the society,this paper comprehensively discussed the methods to determine the thresholds of agricultural product information fluctuation in different time dimensions.Based on the data of the National Bureau of Statistics of China(NBSC)and survey data,this paper used a variety of statistical methods to determine the early warning thresholds of the production,consumption and prices of agricultural products.Combined with Delphi expert judgment correction method,it finally determined the early warning thresholds of agricultural product information in multiple time,and carried out early warning analysis on the fluctuation of agricultural product monitoring information in 2018.The results show that:(1)the daily,weekly and monthly monitoring and early warning thresholds of agricultural products play an important early warning role in monitoring abnormal fluctuations with agricultural products;(2)the multitemporal monitoring and early warning thresholds of agricultural product information identified by the research institute can provide effective early warning on current abnormal fluctuation of agricultural product information,provide a benchmarking standard for China's agricultural production,consumption and price monitoring and early warning at the nat展开更多
This study presents the development of computationally efficient coupling of Navier–Stokes Computational Fluid Dynamics(CFD)with a helicopter flight dynamics model with the ultimate goal of real-time simulation of ai...This study presents the development of computationally efficient coupling of Navier–Stokes Computational Fluid Dynamics(CFD)with a helicopter flight dynamics model with the ultimate goal of real-time simulation of airwake effects in the helicopter/ship Dynamic Interface(DI).The flight dynamics model is free to move within a computational domain,where the main rotor forces are converted to source terms in the momentum equations of the CFD solution using an actuator disk model.Simultaneously,the CFD solver calculates induced velocities that are fed back to the simulation and affect the aerodynamic loads in the flight dynamics.The CFD solver models the inflow,ground effect and interactional aerodynamics in the flight dynamics simulation,and these calculations can be coupled with the solution of the external flow(e.g.,ship airwake effects).The simulation framework for fully-coupled pilot-in-the-loop(PIL)flight dynamics/CFD is demonstrated for a simplified shedding wake.Initial tests were performed with 0.38 million structured grid cells running on 352 processors and showed near-real-time performance.Improvements to the coupling interface are described that allow the simulation run at near-real-time execution speeds on currently available computing platforms.Improvements in computing hardware are expected to allow real-time simulations.展开更多
Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum...Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum at different delay times reflects the population in different electronic states. We inspect the periodicity of vibrational motion in neutral states, and map the vibrational wave-packet propagation in corresponding internuclear coordinate.展开更多
Nitrogen injection under conditions close vicinity of the liquid-gas critical point is studied numerically. The fluid thermodynamic and transport properties vary drasti- cally and exhibit anomalies in the near-critica...Nitrogen injection under conditions close vicinity of the liquid-gas critical point is studied numerically. The fluid thermodynamic and transport properties vary drasti- cally and exhibit anomalies in the near-critical regime. These anomalies can cause distinctive effects on heat-transfer and fluid-flow characteristics. To focus on the influence of ther- modynamics on the flow field, a relatively low injection Reynolds number of 1 750 is adopted. For comparisons, a reference case with the same configuration and Reynolds number is simulated in the ideal gas regime. The model accommodates full conservation laws, real-fluid thermody- namic and transport phenomena. Results reveal that the flow features of the near-critical fluid jet are significantly differ- ent from their counterpart. The near-critical fluid jet spreads faster and mixes more efficiently with the ambient fluid along with a more rapidly development of the vortex pairing pro- cess. Detailed analysis at different streamwise locations in- cluding both the flat shear-layer region and fully developed vortex region reveals the important effect of volume dilata- tion and baroclinic torque in the near-critical fluid case. The former disturbs the shear layer and makes it more unstable. The volume dilatation and baroclinic effects strengthen the vorticity and stimulate the vortex rolling up and pairing pro- cess展开更多
Large dams are complex structures with nonlinear dynamic behavior.Engineers often are forced to assess dam safety based on the available incomplete data,which is extremely difficult.This important problem can be solve...Large dams are complex structures with nonlinear dynamic behavior.Engineers often are forced to assess dam safety based on the available incomplete data,which is extremely difficult.This important problem can be solved with the modern theory of complex systems.It is possible to derive characteristics of the whole unknown dynamics of a structure using few data sets of certain carefully selected representative parameter(s).By means of high quality continuous records of some geotechnical characteristic(s)of a dam and modern methods of time series linear/nonlinear analysis the main dynamical features of the entire,unknown process(here—dam deformation)can be analyzed.We created the cost-effective Monitoring Telemetric System for Dam Diagnostics(DAMWATCH),which consists of sensors(tiltmeters),terminal and central controllers connected by the GSM/GPRS Modem to the diagnostic center.The tilt data recorded for varying reservoir level are compared with static design model of dam deformations computed by a finite element method(FEM)for the dam-reservoir-foundation system.Besides,recently developed linear/nonlinear data analysis and prediction schemes may help to quantify fine dynamical features of the dam behavior.The software package DAMTOOL has been developed for this purpose.The differences between measured and theoretically predicted response parameters of the dam may signal abnormal behavior of the object.The data obtained already by testing of the DAMWATCH/DAMTOOL system during operation of the high Enguri arc dam and reservoir(Georgia)show interesting long-term and short-term patterns of tilts in the dam body,which can be used for dam diagnostics.The proposed real-time telemetric monitoring(DAMWATCH)complex and linear/nonlinear dynamical analysis system(DAMTOOL)are unique.展开更多
We introduce a first-principles density-functional theory,i.e.the finite-difference pseudopotential density- functional theory in real space and the Langevin molecular dynamics annealing technique,to the descriptions ...We introduce a first-principles density-functional theory,i.e.the finite-difference pseudopotential density- functional theory in real space and the Langevin molecular dynamics annealing technique,to the descriptions of structures and some properties of small carbon clusters(C_N,N=2～8).It is shown that the odd-numbered clusters have linear structures and most of the even-numbered clusters prefer cyclic structures.展开更多
We present our recent research results regarding the designing and implementation of real-time physics simulation engines,which aim at developing physics-inspired e-entertainment such as computer games,mobile applicat...We present our recent research results regarding the designing and implementation of real-time physics simulation engines,which aim at developing physics-inspired e-entertainment such as computer games,mobile applications,interactive TV and other smart media in Korea.Our real-time physics engine consists of three functional components:rigid body dynamics simulation,deformable body simulation,and data-driven physics simulation.The core simulation techniques to realize these simulation components include real-time collision detection and response,large-scale model simulation,and character model control.In this paper,we highlight these features and demonstrate their performances.We also showcase some of the gaming applications that we have integrated our physics engine into.展开更多
Applicability of Feynman path integral approach to numerical simulations of quantum dynamics of an electron in real time domain is examined.Coherent quantum dynamics is demonstrated with one dimensional test cases(qua...Applicability of Feynman path integral approach to numerical simulations of quantum dynamics of an electron in real time domain is examined.Coherent quantum dynamics is demonstrated with one dimensional test cases(quantum dot models)and performance of the Trotter kernel as compared with the exact kernels is tested.Also,a novel approach for finding the ground state and other stationary sates is presented.This is based on the incoherent propagation in real time.For both approaches the Monte Carlo grid and sampling are tested and compared with regular grids and sampling.We asses the numerical prerequisites for all of the above.展开更多
基金supported by the National Natural Science Foundation of China (NSFC) (Nos. 62005208, 62135003, and 61905189)Innovation Capability Support Program of Shaanxi (No. 2021TD-57)+1 种基金China Postdoctoral Science Foundation (Nos. 2020M673365 and 2019M663656)National Institutes of Health Grant GM100156 to PRB
文摘Super-resolution structured illumination microscopy(SR-SIM)is an outstanding method for visualizing the subcellular dynamics in living cells.To date,by using elaborately designed systems and algorithms,SR-SIM can achieve rapid,optically sectioned,SR observation with hundreds to thousands of time points.However,real-time observation is still out of reach for most SIM setups as conventional algorithms for image reconstruction involve a heavy computing burden.To address this limitation,an accelerated reconstruction algorithm was developed by implementing a simplified workflow for SR-SIM,termed joint space and frequency reconstruction.This algorithm results in an 80-fold improvement in reconstruction speed relative to the widely used Wiener-SIM.Critically,the increased processing speed does not come at the expense of spatial resolution or sectioning capability,as demonstrated by live imaging of microtubule dynamics and mitochondrial tubulation.
基金supported in part by the National Program on Key Basic Research Project 973 Program under Grant 2013CB733103the Program for New Century Excellent Talents in University under Grand NCET-10-0058
文摘Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.
基金supported by the National Natural Science Foundation of China(Grant Nos.12261131495,12075210,and 12275240)the Scientific Research and Development Fund of Zhejiang A&F University(Grant No.2021FR0009)。
文摘Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are scarce.In this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are realized.The generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three wavelengths.Positive and negative dispersion lead to different group velocities of solitons.The presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an explosion.With an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental results.This work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.
基金financially supported by the National Natural Science Foundation of China,No.61263011,81000554Program in Sun Yat-sen University supported by Fundamental Research Funds for the Central Universities,No.11ykpy07+1 种基金Natural Science Foundation of Guangdong Province,No.S2011010005309Innovation Fund of Xinjiang Medical University,No.XJC201209
文摘The automatic detection and identification of electroencephalogram waves play an important role in the prediction, diagnosis and treatment of epileptic seizures. In this study, a nonlinear dynamics index–approximate entropy and a support vector machine that has strong generalization ability were applied to classify electroencephalogram signals at epileptic interictal and ictal periods. Our aim was to verify whether approximate entropy waves can be effectively applied to the automatic real-time detection of epilepsy in the electroencephalogram, and to explore its generalization ability as a classifier trained using a nonlinear dynamics index. Four patients presenting with partial epileptic seizures were included in this study. They were all diagnosed with neocortex localized epilepsy and epileptic foci were clearly observed by electroencephalogram. The electroencephalogram data form the four involved patients were segmented and the characteristic values of each segment, that is, the approximate entropy, were extracted. The support vector machine classifier was constructed with the approximate entropy extracted from one epileptic case, and then electroencephalogram waves of the other three cases were classified, reaching a 93.33% accuracy rate. Our findings suggest that the use of approximate entropy allows the automatic real-time detection of electroencephalogram data in epileptic cases. The combination of approximate entropy and support vector machines shows good generalization ability for the classification of electroencephalogram signals for epilepsy.
基金supported by the National Natural Science Foundation of China(Grant Nos.11074151 and 11304185)
文摘Quantum dynamics calculations for the title reaction H（2S） ＋ S2（X3∑g） → SH（X2П） ＋S（3P） are performed byusing a globally accurate double many-body expansion potential energy surface [J. Phys. Chem. A 115 5274 （2011）]. The Chebyshev real wave packet propagation method is employed to obtain the dynamical information, such as reaction probability, initial state-specified integral cross section, and thermal rate constant. It is found not only that there is a reaction threshold near 0.7 eV in both reaction probabilities and integral cross section curves, but also that both the probability and cross section increase firstly and then decrease as the collision energy increases. The existence of the resonance structure in both the probability and cross section curves is ascribed to the deep potential well. The calculation of the rate constant reveals that the reaction occurring on the potential energy surface of the ground-state HS2 is slow to take place.
基金The Science and Technoloav Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2020-A11-02)is appreciated for supporting this study.
文摘Monitoring and early warning is an important means to effectively prevent risks in agricultural production,consumption and price.In particular,with the change of modes of national administration against the background of big data,improving the capacity to monitor agricultural products is of great significance for macroeconomic decision-making.Agricultural product information early warning thresholds are the core of agricultural product monitoring and early warning.How to appropriately determine the early warning thresholds of multi-temporal agricultural product information is a key question to realize real-time and dynamic monitoring and early warning.Based on the theory of abnormal fluctuation of agricultural product information and the research of substantive impact on the society,this paper comprehensively discussed the methods to determine the thresholds of agricultural product information fluctuation in different time dimensions.Based on the data of the National Bureau of Statistics of China(NBSC)and survey data,this paper used a variety of statistical methods to determine the early warning thresholds of the production,consumption and prices of agricultural products.Combined with Delphi expert judgment correction method,it finally determined the early warning thresholds of agricultural product information in multiple time,and carried out early warning analysis on the fluctuation of agricultural product monitoring information in 2018.The results show that:(1)the daily,weekly and monthly monitoring and early warning thresholds of agricultural products play an important early warning role in monitoring abnormal fluctuations with agricultural products;(2)the multitemporal monitoring and early warning thresholds of agricultural product information identified by the research institute can provide effective early warning on current abnormal fluctuation of agricultural product information,provide a benchmarking standard for China's agricultural production,consumption and price monitoring and early warning at the nat
基金the Office of Naval Research,ONR,under Grant/Contract numbers N00014-14-C-0020(PSU)and N00014-13-C-0456(CRAFT Tech).
文摘This study presents the development of computationally efficient coupling of Navier–Stokes Computational Fluid Dynamics(CFD)with a helicopter flight dynamics model with the ultimate goal of real-time simulation of airwake effects in the helicopter/ship Dynamic Interface(DI).The flight dynamics model is free to move within a computational domain,where the main rotor forces are converted to source terms in the momentum equations of the CFD solution using an actuator disk model.Simultaneously,the CFD solver calculates induced velocities that are fed back to the simulation and affect the aerodynamic loads in the flight dynamics.The CFD solver models the inflow,ground effect and interactional aerodynamics in the flight dynamics simulation,and these calculations can be coupled with the solution of the external flow(e.g.,ship airwake effects).The simulation framework for fully-coupled pilot-in-the-loop(PIL)flight dynamics/CFD is demonstrated for a simplified shedding wake.Initial tests were performed with 0.38 million structured grid cells running on 352 processors and showed near-real-time performance.Improvements to the coupling interface are described that allow the simulation run at near-real-time execution speeds on currently available computing platforms.Improvements in computing hardware are expected to allow real-time simulations.
基金Supported by the National Natural Science Foundation of China under Grant No 10575017.
文摘Effect of laser fields on Na2 interaction potentials is studied by calculating the time-resolved photoelectron spectrum （TRPES） with the time-dependent wave-packet method. It is shown that the photoelectron spectrum at different delay times reflects the population in different electronic states. We inspect the periodicity of vibrational motion in neutral states, and map the vibrational wave-packet propagation in corresponding internuclear coordinate.
基金supported in part by the National Natural Science Foundation of China (11132010 and 11072236)
文摘Nitrogen injection under conditions close vicinity of the liquid-gas critical point is studied numerically. The fluid thermodynamic and transport properties vary drasti- cally and exhibit anomalies in the near-critical regime. These anomalies can cause distinctive effects on heat-transfer and fluid-flow characteristics. To focus on the influence of ther- modynamics on the flow field, a relatively low injection Reynolds number of 1 750 is adopted. For comparisons, a reference case with the same configuration and Reynolds number is simulated in the ideal gas regime. The model accommodates full conservation laws, real-fluid thermody- namic and transport phenomena. Results reveal that the flow features of the near-critical fluid jet are significantly differ- ent from their counterpart. The near-critical fluid jet spreads faster and mixes more efficiently with the ambient fluid along with a more rapidly development of the vortex pairing pro- cess. Detailed analysis at different streamwise locations in- cluding both the flat shear-layer region and fully developed vortex region reveals the important effect of volume dilata- tion and baroclinic torque in the near-critical fluid case. The former disturbs the shear layer and makes it more unstable. The volume dilatation and baroclinic effects strengthen the vorticity and stimulate the vortex rolling up and pairing pro- cess
基金the financial support of joint project(#5016)of Georgian National Scientific Foundation(GNSF)and ScienceTechnology Center of Ukraine(STCU)and Open Partial Agreement on the Major Disasters at the Council of Europe(EUR-OPA).
文摘Large dams are complex structures with nonlinear dynamic behavior.Engineers often are forced to assess dam safety based on the available incomplete data,which is extremely difficult.This important problem can be solved with the modern theory of complex systems.It is possible to derive characteristics of the whole unknown dynamics of a structure using few data sets of certain carefully selected representative parameter(s).By means of high quality continuous records of some geotechnical characteristic(s)of a dam and modern methods of time series linear/nonlinear analysis the main dynamical features of the entire,unknown process(here—dam deformation)can be analyzed.We created the cost-effective Monitoring Telemetric System for Dam Diagnostics(DAMWATCH),which consists of sensors(tiltmeters),terminal and central controllers connected by the GSM/GPRS Modem to the diagnostic center.The tilt data recorded for varying reservoir level are compared with static design model of dam deformations computed by a finite element method(FEM)for the dam-reservoir-foundation system.Besides,recently developed linear/nonlinear data analysis and prediction schemes may help to quantify fine dynamical features of the dam behavior.The software package DAMTOOL has been developed for this purpose.The differences between measured and theoretically predicted response parameters of the dam may signal abnormal behavior of the object.The data obtained already by testing of the DAMWATCH/DAMTOOL system during operation of the high Enguri arc dam and reservoir(Georgia)show interesting long-term and short-term patterns of tilts in the dam body,which can be used for dam diagnostics.The proposed real-time telemetric monitoring(DAMWATCH)complex and linear/nonlinear dynamical analysis system(DAMTOOL)are unique.
基金The project supported by National Natural Science Foundation of China under Grant No.10274055the Research Fund for the Doctoral Program of High Education of China under Grant No.20020610001
文摘We introduce a first-principles density-functional theory,i.e.the finite-difference pseudopotential density- functional theory in real space and the Langevin molecular dynamics annealing technique,to the descriptions of structures and some properties of small carbon clusters(C_N,N=2～8).It is shown that the odd-numbered clusters have linear structures and most of the even-numbered clusters prefer cyclic structures.
基金supported in part by IT R&D program of MKE/MCST/KOCCA(KI001818)NRF grant funded by the Korea government(MEST)(No.2012R1A2A2A01046246,No.2012R1A2A2A06047007).
文摘We present our recent research results regarding the designing and implementation of real-time physics simulation engines,which aim at developing physics-inspired e-entertainment such as computer games,mobile applications,interactive TV and other smart media in Korea.Our real-time physics engine consists of three functional components:rigid body dynamics simulation,deformable body simulation,and data-driven physics simulation.The core simulation techniques to realize these simulation components include real-time collision detection and response,large-scale model simulation,and character model control.In this paper,we highlight these features and demonstrate their performances.We also showcase some of the gaming applications that we have integrated our physics engine into.
文摘Applicability of Feynman path integral approach to numerical simulations of quantum dynamics of an electron in real time domain is examined.Coherent quantum dynamics is demonstrated with one dimensional test cases(quantum dot models)and performance of the Trotter kernel as compared with the exact kernels is tested.Also,a novel approach for finding the ground state and other stationary sates is presented.This is based on the incoherent propagation in real time.For both approaches the Monte Carlo grid and sampling are tested and compared with regular grids and sampling.We asses the numerical prerequisites for all of the above.
