An extended π calculus was introduced to deal with secure movement and intercommunication between agents. The system extends Nomadic-π with objective migration primitive and confined region which serves as annotatio...An extended π calculus was introduced to deal with secure movement and intercommunication between agents. The system extends Nomadic-π with objective migration primitive and confined region which serves as annotation labels of agents and channels. The confined region labels were used to uniquely identify the constraints on the migration and communication of agents, with the labels, the agents could be confined in a secure subsystem and the inter-agent communication could be confined between agents located on trusted sites during computation. The operational semantics for the calculus was given out, and a type system which enforces security properties called confined migration and confined communication was developed.展开更多
To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle's (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster an...To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle's (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV's motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.展开更多
We perform langevin dynamics simulation for envelope solitons in an FPU-β lattice,with the nearestneighborinteraction and quartic anharmonicity.We get the motion equations of our discrete system by adding noiseand da...We perform langevin dynamics simulation for envelope solitons in an FPU-β lattice,with the nearestneighborinteraction and quartic anharmonicity.We get the motion equations of our discrete system by adding noiseand damping to the set of deterministic motion equations.We define'half-time'as the time when the amplitude of theenvelope soliton decreases by half due to damping.And then the mass,center and half-time of the perturbed envelopesoliton are numerically simulated,beginning with the discrete envelope soliton at rest.Results show successfully hownoise affects behavior of the envelope soliton.展开更多
Driving simulators involve the capability of simulating critical and dangerous driving situations up to the limits of active safety. They are employed for investigating the interactions of the driver-vehicle system un...Driving simulators involve the capability of simulating critical and dangerous driving situations up to the limits of active safety. They are employed for investigating the interactions of the driver-vehicle system under reproducible and non-dangerous conditions. Because of their flexibility they are well established in scientific research. They are mainly used in current automotive fields of research like driver assistance and autonomous driving systems. The development of assistance systems makes the human being as the directly concerned component irreplaceable in the development process. Here the use of driving simulators has become an essential element, because they offer the possibility to integrate the human being as a real part into the simulation environment. It must be considered that the circuit of information has to be the same as under real driving conditions. Otherwise the results are not transferable. This paper deals with the possibilities of presenting all information to the driver, which are necessary to give him a realistic impression of driving. A main subject is the sensation of yaw-movements, which could be of interest when novel kinds of moving base systems are designed.展开更多
In principle, non-Hermitian quantum equations of motion can be formulated using as a starting point either the Heisenberg's or the Schroedinger's picture of quantum dynamics. Here it is shown in both cases how to ma...In principle, non-Hermitian quantum equations of motion can be formulated using as a starting point either the Heisenberg's or the Schroedinger's picture of quantum dynamics. Here it is shown in both cases how to map the algebra of commutators, defining the time evolution in terms of a non-Hermitian Hamiltonian, onto a non-Hamiltonian algebra with a Hermitian Hamiltonian. The logic behind such a derivation is reversible, so that any Hermitian Hamiltonian can be used in the formulation of non-Hermitian dynamics through a suitable algebra of generalized (non-Hamiltonian) commutators. These results provide a general structure (a template) for non-Hermitian equations of motion to be used in the computer simulation of open quantum systems dynamics.展开更多
基金The National Defense Project of China(No417010602)
文摘An extended π calculus was introduced to deal with secure movement and intercommunication between agents. The system extends Nomadic-π with objective migration primitive and confined region which serves as annotation labels of agents and channels. The confined region labels were used to uniquely identify the constraints on the migration and communication of agents, with the labels, the agents could be confined in a secure subsystem and the inter-agent communication could be confined between agents located on trusted sites during computation. The operational semantics for the calculus was given out, and a type system which enforces security properties called confined migration and confined communication was developed.
基金Supported by the National Natural Science Foundation of China under Grant No.50909025
文摘To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle's (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV's motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.
基金Supported by Scientific Research Fund of Hunan Provincial Education Department under Grant No.07B075Interactive Project Fund of Xiangtan University under Grant No.061ND09Initial Scientific Research Fund of Xiangtan University
文摘We perform langevin dynamics simulation for envelope solitons in an FPU-β lattice,with the nearestneighborinteraction and quartic anharmonicity.We get the motion equations of our discrete system by adding noiseand damping to the set of deterministic motion equations.We define'half-time'as the time when the amplitude of theenvelope soliton decreases by half due to damping.And then the mass,center and half-time of the perturbed envelopesoliton are numerically simulated,beginning with the discrete envelope soliton at rest.Results show successfully hownoise affects behavior of the envelope soliton.
文摘Driving simulators involve the capability of simulating critical and dangerous driving situations up to the limits of active safety. They are employed for investigating the interactions of the driver-vehicle system under reproducible and non-dangerous conditions. Because of their flexibility they are well established in scientific research. They are mainly used in current automotive fields of research like driver assistance and autonomous driving systems. The development of assistance systems makes the human being as the directly concerned component irreplaceable in the development process. Here the use of driving simulators has become an essential element, because they offer the possibility to integrate the human being as a real part into the simulation environment. It must be considered that the circuit of information has to be the same as under real driving conditions. Otherwise the results are not transferable. This paper deals with the possibilities of presenting all information to the driver, which are necessary to give him a realistic impression of driving. A main subject is the sensation of yaw-movements, which could be of interest when novel kinds of moving base systems are designed.
基金Supported by the National Research Foundation of South Africa
文摘In principle, non-Hermitian quantum equations of motion can be formulated using as a starting point either the Heisenberg's or the Schroedinger's picture of quantum dynamics. Here it is shown in both cases how to map the algebra of commutators, defining the time evolution in terms of a non-Hermitian Hamiltonian, onto a non-Hamiltonian algebra with a Hermitian Hamiltonian. The logic behind such a derivation is reversible, so that any Hermitian Hamiltonian can be used in the formulation of non-Hermitian dynamics through a suitable algebra of generalized (non-Hamiltonian) commutators. These results provide a general structure (a template) for non-Hermitian equations of motion to be used in the computer simulation of open quantum systems dynamics.