The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relations...The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relationship between dynamic modal flexibility and modal flexibility, which is used to find out the dangerous model of the transmission system and its weak areas. Then design parameters of weak areas are modified, the new one from the old structure is put forward, and the dynamic characteristics of new ...展开更多
In order to fulfill the goal of autonomous walking on rough terrain,a distributed gait planningmethod applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait co-ordination mecha...In order to fulfill the goal of autonomous walking on rough terrain,a distributed gait planningmethod applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait co-ordination mechanism of stick insect.The mathematical relation of walking velocity and gait pattern wasdepicted,a set of local rules operating between adjacent legs were put forward,and a distributed networkof local rules for gait control was constructed.With the interaction of adjacent legs,adaptive adjustmentof phase sequence fluctuation of walking legs resulting from change of terrain conditions or variety of walk-ing speed was implemented to generate statically stable gait.In the simulation experiments,adaptive ad-justment of inter-leg phase sequence and smooth transition of velocity and gait pattern were realized,andstatic stableness was ensured simultaneously,which provided the hexapod robot with the capability ofwalking on rough terrain stably and expeditiously.展开更多
A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based o...A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based on which the modeling simplifications are proposed. Then, the mathematical models for the evaporator, cabinet and duct-fan are presented. The whole system is divided into two subsystems--refrigerant cycling system and air cycling system. In order to simplify the model, two closed-loop systems are broken into the compressor component and the evaporator component, respectively. A general distributed parameter model is employed for evaporator with homogeneous flow to simplify the two-phase evaporating flow region. The z-transfer function model is used to describe the cabinet load. Computational fluid dynamics （CFD） method is employed to obtain the pressure drop and flow rate curve of the duct-fan model.展开更多
Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edg...Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edges.The average degree of the network of nuclear decay is about 1.8,the cumulative degree distribution still meets the typical power-law distribution,and the corresponding exponent is about 4.1.Not considering their dynamic behavior,the fitting parameters of the nuclear decay network are obtained according to the LUHNM theory proposed by our group before.Their cumulated degree distributions of the nuclear decay network match well.The idea and method may provide a new way to study some other problems of nuclear physics.展开更多
The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried ou...The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried out to study'pull-down'and steady-state performance of the RF,and to determine how the experiment and simulation temperature stack up against each other.Good match is found between simulated and measured results for the'pull-down'period.For the steady-state period,the simulation results are also found to agree well with experiment ones except for the temperature profiles of the refrigerator compartment(RC) and freezer compartment(FC).The average temperature and the energy consumption errors between measurement and simulation are less than 10%.Although the model can not reflect the non-uniform air temperature fields in the RC and FC,the variation range and periodicities of the temperature correlate well between the simulation and experiment.We conclude that such a model is valid for investigating the performance of no-frost refrigerator.展开更多
文摘The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relationship between dynamic modal flexibility and modal flexibility, which is used to find out the dangerous model of the transmission system and its weak areas. Then design parameters of weak areas are modified, the new one from the old structure is put forward, and the dynamic characteristics of new ...
基金Supported by the National High Technology Research and Development Programme of China (No. 2006AA04Z245)by the Progran for Changjiang Scholars and Innovative Research Team in University of China (PCSIRT) (IRT0423)
文摘In order to fulfill the goal of autonomous walking on rough terrain,a distributed gait planningmethod applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait co-ordination mechanism of stick insect.The mathematical relation of walking velocity and gait pattern wasdepicted,a set of local rules operating between adjacent legs were put forward,and a distributed networkof local rules for gait control was constructed.With the interaction of adjacent legs,adaptive adjustmentof phase sequence fluctuation of walking legs resulting from change of terrain conditions or variety of walk-ing speed was implemented to generate statically stable gait.In the simulation experiments,adaptive ad-justment of inter-leg phase sequence and smooth transition of velocity and gait pattern were realized,andstatic stableness was ensured simultaneously,which provided the hexapod robot with the capability ofwalking on rough terrain stably and expeditiously.
文摘A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based on which the modeling simplifications are proposed. Then, the mathematical models for the evaporator, cabinet and duct-fan are presented. The whole system is divided into two subsystems--refrigerant cycling system and air cycling system. In order to simplify the model, two closed-loop systems are broken into the compressor component and the evaporator component, respectively. A general distributed parameter model is employed for evaporator with homogeneous flow to simplify the two-phase evaporating flow region. The z-transfer function model is used to describe the cabinet load. Computational fluid dynamics （CFD） method is employed to obtain the pressure drop and flow rate curve of the duct-fan model.
基金Supported by National Natural Science Foundation of China under Grant Nos. 60874087 and 61174151
文摘Nuclear decay is investigated by the view of network science and the relationship of nuclear decay among different radionuclide can be mapped to a network topology directly.The network includes 1410 nodes and 1275 edges.The average degree of the network of nuclear decay is about 1.8,the cumulative degree distribution still meets the typical power-law distribution,and the corresponding exponent is about 4.1.Not considering their dynamic behavior,the fitting parameters of the nuclear decay network are obtained according to the LUHNM theory proposed by our group before.Their cumulated degree distributions of the nuclear decay network match well.The idea and method may provide a new way to study some other problems of nuclear physics.
文摘The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried out to study'pull-down'and steady-state performance of the RF,and to determine how the experiment and simulation temperature stack up against each other.Good match is found between simulated and measured results for the'pull-down'period.For the steady-state period,the simulation results are also found to agree well with experiment ones except for the temperature profiles of the refrigerator compartment(RC) and freezer compartment(FC).The average temperature and the energy consumption errors between measurement and simulation are less than 10%.Although the model can not reflect the non-uniform air temperature fields in the RC and FC,the variation range and periodicities of the temperature correlate well between the simulation and experiment.We conclude that such a model is valid for investigating the performance of no-frost refrigerator.
