The purpose of this study is to develop maneuvering models and systems of a simulator to improve the motion performance of autonomous underwater vehicles （AUVs） at the preliminary design stages in advance. The AUVs ...The purpose of this study is to develop maneuvering models and systems of a simulator to improve the motion performance of autonomous underwater vehicles （AUVs） at the preliminary design stages in advance. The AUVs simulation systems based on the standard submarine equations of motion in six-degree-of-freedom （6-DOF） integrated with the Euler-Rodriguez quaternion method for representing singularity-free AUV attitude and time-saving calculation, and with a nonlinear control model for maneuvering and depth control simulations, time-marching in the fourth-order Runge-Kutta scheme. For validation of the simulation codes, results of the ISiMI AUV open-loop tests including turning test and zigzag test as well as an AUV simulator on the basis of Euler-angle method were used to compare with the quaternion-based AUV simulator. The computational results from the proposed simulator agree well with those from both the ISiMI AUV experiments and the Euler-angle based simulations. Additionally, a new maneuvering procedure, namely ＂put-out＂ was implemented to test directional stability for a large-scale AUV in the proposed AUV simulator that can be considered for vehicles in space as well as in constrained planes.展开更多
Demand for solving systemic problems has resulted in the need for new forms of innovation.Accordingly,the concept of innovation ecosystem has emerged.Ecosystems are intrinsically more fluid than networks,which set ups...Demand for solving systemic problems has resulted in the need for new forms of innovation.Accordingly,the concept of innovation ecosystem has emerged.Ecosystems are intrinsically more fluid than networks,which set ups the need to understand and orchestrate the internal dynamics of innovation ecosystem in order to have successful innovation outcomes.The dynamics of ecosystems,however,is not well understood.In this paper the dynamics of innovation ecosystems has been studied by applying the methodology of system dynamics.The purpose of the study is to support the creation of innovation ecosystems and the orchestration of existing ecosystems so that they could be more successful.Key factors generating dynamics in innovation ecosystems were identified.They form the elements of the system dynamics model of innovation ecosystems.The causal loop structure between the model elements indicates how the key factors of dynamics influence the outcome of ecosystem.展开更多
In the past there were a lot of researches on the topic of economic growth. Nevertheless, the environment has been a bit abstracted by standard economics. Scarce natural resources and our choices to protect them or ex...In the past there were a lot of researches on the topic of economic growth. Nevertheless, the environment has been a bit abstracted by standard economics. Scarce natural resources and our choices to protect them or exploit them jointly determine the economic and environmental systems. In this paper we describe a model with a particular focus on the relationship among income, pollution, and non-renewable resources. We want to combine both economic and environmental sectors. The system dynamics approach is used in analyzing these complex relationships. This paper gives an insight into the possibilities for replacing non-renewable resources with more renewable ones. Next, we present the simulation runs of the model that are conducted with the help of existing system dynamics modeling tools. Only the relationships simulated so far between the variables ought to be put under yet more cautious examination.展开更多
文摘The purpose of this study is to develop maneuvering models and systems of a simulator to improve the motion performance of autonomous underwater vehicles （AUVs） at the preliminary design stages in advance. The AUVs simulation systems based on the standard submarine equations of motion in six-degree-of-freedom （6-DOF） integrated with the Euler-Rodriguez quaternion method for representing singularity-free AUV attitude and time-saving calculation, and with a nonlinear control model for maneuvering and depth control simulations, time-marching in the fourth-order Runge-Kutta scheme. For validation of the simulation codes, results of the ISiMI AUV open-loop tests including turning test and zigzag test as well as an AUV simulator on the basis of Euler-angle method were used to compare with the quaternion-based AUV simulator. The computational results from the proposed simulator agree well with those from both the ISiMI AUV experiments and the Euler-angle based simulations. Additionally, a new maneuvering procedure, namely ＂put-out＂ was implemented to test directional stability for a large-scale AUV in the proposed AUV simulator that can be considered for vehicles in space as well as in constrained planes.
文摘Demand for solving systemic problems has resulted in the need for new forms of innovation.Accordingly,the concept of innovation ecosystem has emerged.Ecosystems are intrinsically more fluid than networks,which set ups the need to understand and orchestrate the internal dynamics of innovation ecosystem in order to have successful innovation outcomes.The dynamics of ecosystems,however,is not well understood.In this paper the dynamics of innovation ecosystems has been studied by applying the methodology of system dynamics.The purpose of the study is to support the creation of innovation ecosystems and the orchestration of existing ecosystems so that they could be more successful.Key factors generating dynamics in innovation ecosystems were identified.They form the elements of the system dynamics model of innovation ecosystems.The causal loop structure between the model elements indicates how the key factors of dynamics influence the outcome of ecosystem.
文摘In the past there were a lot of researches on the topic of economic growth. Nevertheless, the environment has been a bit abstracted by standard economics. Scarce natural resources and our choices to protect them or exploit them jointly determine the economic and environmental systems. In this paper we describe a model with a particular focus on the relationship among income, pollution, and non-renewable resources. We want to combine both economic and environmental sectors. The system dynamics approach is used in analyzing these complex relationships. This paper gives an insight into the possibilities for replacing non-renewable resources with more renewable ones. Next, we present the simulation runs of the model that are conducted with the help of existing system dynamics modeling tools. Only the relationships simulated so far between the variables ought to be put under yet more cautious examination.
