In this book new results on controller design techniques for the tracking of generic reference inputs are presented. They allow the design of a controller for an uncertain process, either continuous or discrete-time, ...In this book new results on controller design techniques for the tracking of generic reference inputs are presented. They allow the design of a controller for an uncertain process, either continuous or discrete-time, without zeros, and with measurable state. The controller guarantees that the control system is Type 1 and has the desired constant gain and poles or that the control system tracks, with a specified maximum error and with a specified maximum time constant, a generic reference with bounded derivative (variation in the discrete-time case), also in the presence of a generic disturbance with bounded derivative (variation). In addition, it is considered the case in which the reference is known a priori. The utility and the efficiency of the proposed methods are illustrated with attractive and significant examples of motion control and temperature control. This book is useful for the design of control systems, especially for manufacturing systems, that are versatile, fast, precise and robust.展开更多
The announcement of major sporting events scheduled to take place in Rio de Janeiro in the coming years is now producing several radical urban transformations that are attracting the attention of renowned architects o...The announcement of major sporting events scheduled to take place in Rio de Janeiro in the coming years is now producing several radical urban transformations that are attracting the attention of renowned architects of the international circuit. All this is happening in a city where relevant architectural references have not been produced for a long while because of the prolonged economic crisis of the past. Despite these conditions, people were able to detect “invisible” design lessons to be learned in this city by sharing perceptual experiences with foreign observers who are, by definition, unaware of their preconceptions. This paper deals with the development of a strategy for re-presenting design references that are locally rooted and accessible for direct embodied experience. The strategy put forward a MPI (metropolitan performance index) drawn out from a bibliographical survey coupled with analytical spatial diagrams of different case-studies presented as a tour guide for the recognition of the architecture produced in Rio de Janeiro. It is believed that this strategy can favor the adoption of an eye attuned to contemporary theories especially interested in the spatial and programmatic concerns that today instigate the designer.展开更多
Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Ac...Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Activity, Method, Object and Information. Based on these four elements, a reference framework called AMOI is proposed to be the guideline for the systematic concurrent product design. Using the AMOI reference framework, concurrent product development system can be structured into four function models (including the activity model, method model, object model and information model) which are interconnected with each other.展开更多
The format for citations in text and for bibliographic references follows GB/T 7714-2005.The citation should be ordered in number as it appears in the text of the submitted article.For journal article Sun,Y.,Li,B.,&am...The format for citations in text and for bibliographic references follows GB/T 7714-2005.The citation should be ordered in number as it appears in the text of the submitted article.For journal article Sun,Y.,Li,B.,&Qu,J.F.Design and implementation of library intelligent IM reference robot.New Technology of Library and Information Service(in Chinese),2011,205:88-92.Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing relational data in XML.ACM Transactions on Database Systems,2002,27(4):438-493.展开更多
Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport (SST) k-w turbulence model to predict the trans...Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport (SST) k-w turbulence model to predict the transition region for a laminar-turbulent boundary layer. The non-uniform free-form deformation (NFFD) method based on the non-uniform rational B-spline (NURBS) basis function is introduced to the airfoil parameterization. The non-dominated sorting genetic algorithm-II (NSGA-II) is used as the search algo- rithm, and the surrogate model based on the Kriging models is introduced to improve the efficiency of the optimization system. The optimization system is set up based on the above technologies, and the robust design about the uncertainty of the Mach number is carried out for NASA0412 airfoil. The optimized airfoil is analyzed and compared with the original airfoil. The results show that natural laminar flow can be achieved on a supercritical airfoil to improve the aerodynamic characteristic of airfoils.展开更多
Ocean wave energy converters(WECs) are obtaining more and more attentions in the world. So far, many types of converters have been invented. Oscillating body systems are a major class of WECs, which typically have one...Ocean wave energy converters(WECs) are obtaining more and more attentions in the world. So far, many types of converters have been invented. Oscillating body systems are a major class of WECs, which typically have one degree of freedom(DOF), and the power absorption efficiency is not quite satisfactory. In this paper, a 3-DOF WEC is proposed and a simplified frequency-domain dynamic model of the WEC depending on the linear potential theory is conducted. The performances of three geometries of the oscillating body including the cone, the cylinder and the hemisphere have been compared, and the results show that the hemisphere is more suitable for the 3-DOF WEC.Subsequently, the relationship among the parameters of the hemisphere is established based on the equal natural frequencies of the heave and pitch(or roll) motions, and the results show that lowering the center of gravity leads to the better power absorption in the pitch(or roll) motion. In the end, the power matrixes of different sizes of the hemispheres under different irregular waves are obtained, which can give a size design reference for engineers.展开更多
This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitutio...This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.展开更多
Structural safety against collapse will be ensured on the condition that stresses and strains in each element of concrete and reinforcement do not exceed the set limits. Different from the general design method, the r...Structural safety against collapse will be ensured on the condition that stresses and strains in each element of concrete and reinforcement do not exceed the set limits. Different from the general design method, the required amounts of longitudinal and stirrup reinforcements in reinforced concrete beam under certain loads by the finite element design method are interactive. There is an approximate hyperbolic relation between them. Considering economy and the design principle that beam should be stronger for shear and weaker for bending, even the yield point of longitudinal reinforcement is taken as reference point for design. According to this point, a real-life beam is designed and the design steps of the finite element method are discussed.展开更多
Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optic...Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optical system by taking into account the system tasks(i.e., target detection and tracking). We then propose a new non-dominated sorting genetic algorithm(NSGA) to maximize the system surveillance performance. Pareto optimal sets are employed to deal with the conflicts due to the presence of multiple cost functions. Simulation results verify the validity and the improved performance of the proposed technique over benchmark methods.展开更多
文摘In this book new results on controller design techniques for the tracking of generic reference inputs are presented. They allow the design of a controller for an uncertain process, either continuous or discrete-time, without zeros, and with measurable state. The controller guarantees that the control system is Type 1 and has the desired constant gain and poles or that the control system tracks, with a specified maximum error and with a specified maximum time constant, a generic reference with bounded derivative (variation in the discrete-time case), also in the presence of a generic disturbance with bounded derivative (variation). In addition, it is considered the case in which the reference is known a priori. The utility and the efficiency of the proposed methods are illustrated with attractive and significant examples of motion control and temperature control. This book is useful for the design of control systems, especially for manufacturing systems, that are versatile, fast, precise and robust.
文摘The announcement of major sporting events scheduled to take place in Rio de Janeiro in the coming years is now producing several radical urban transformations that are attracting the attention of renowned architects of the international circuit. All this is happening in a city where relevant architectural references have not been produced for a long while because of the prolonged economic crisis of the past. Despite these conditions, people were able to detect “invisible” design lessons to be learned in this city by sharing perceptual experiences with foreign observers who are, by definition, unaware of their preconceptions. This paper deals with the development of a strategy for re-presenting design references that are locally rooted and accessible for direct embodied experience. The strategy put forward a MPI (metropolitan performance index) drawn out from a bibliographical survey coupled with analytical spatial diagrams of different case-studies presented as a tour guide for the recognition of the architecture produced in Rio de Janeiro. It is believed that this strategy can favor the adoption of an eye attuned to contemporary theories especially interested in the spatial and programmatic concerns that today instigate the designer.
文摘Considering the diversity of methods and tools offered to concurrent engineering, the aspects playing important roles in the concurrent engineering context have been pinpointed as being four core elements which are Activity, Method, Object and Information. Based on these four elements, a reference framework called AMOI is proposed to be the guideline for the systematic concurrent product design. Using the AMOI reference framework, concurrent product development system can be structured into four function models (including the activity model, method model, object model and information model) which are interconnected with each other.
文摘The format for citations in text and for bibliographic references follows GB/T 7714-2005.The citation should be ordered in number as it appears in the text of the submitted article.For journal article Sun,Y.,Li,B.,&Qu,J.F.Design and implementation of library intelligent IM reference robot.New Technology of Library and Information Service(in Chinese),2011,205:88-92.Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing relational data in XML.ACM Transactions on Database Systems,2002,27(4):438-493.
文摘Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport (SST) k-w turbulence model to predict the transition region for a laminar-turbulent boundary layer. The non-uniform free-form deformation (NFFD) method based on the non-uniform rational B-spline (NURBS) basis function is introduced to the airfoil parameterization. The non-dominated sorting genetic algorithm-II (NSGA-II) is used as the search algo- rithm, and the surrogate model based on the Kriging models is introduced to improve the efficiency of the optimization system. The optimization system is set up based on the above technologies, and the robust design about the uncertainty of the Mach number is carried out for NASA0412 airfoil. The optimized airfoil is analyzed and compared with the original airfoil. The results show that natural laminar flow can be achieved on a supercritical airfoil to improve the aerodynamic characteristic of airfoils.
基金financially supported by China Postdoctoral Science Foundation(Grant No.2017M611554)the National Natural Science Foundation of China(Grant No.51335007)
文摘Ocean wave energy converters(WECs) are obtaining more and more attentions in the world. So far, many types of converters have been invented. Oscillating body systems are a major class of WECs, which typically have one degree of freedom(DOF), and the power absorption efficiency is not quite satisfactory. In this paper, a 3-DOF WEC is proposed and a simplified frequency-domain dynamic model of the WEC depending on the linear potential theory is conducted. The performances of three geometries of the oscillating body including the cone, the cylinder and the hemisphere have been compared, and the results show that the hemisphere is more suitable for the 3-DOF WEC.Subsequently, the relationship among the parameters of the hemisphere is established based on the equal natural frequencies of the heave and pitch(or roll) motions, and the results show that lowering the center of gravity leads to the better power absorption in the pitch(or roll) motion. In the end, the power matrixes of different sizes of the hemispheres under different irregular waves are obtained, which can give a size design reference for engineers.
基金Foundation item: Supported by the National Special Fund for Agro-scientific Research in the Public Interest (No.201003024), and the National Natural Science Foundation of China (No.51409042 No. 51209034).
文摘This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.
文摘Structural safety against collapse will be ensured on the condition that stresses and strains in each element of concrete and reinforcement do not exceed the set limits. Different from the general design method, the required amounts of longitudinal and stirrup reinforcements in reinforced concrete beam under certain loads by the finite element design method are interactive. There is an approximate hyperbolic relation between them. Considering economy and the design principle that beam should be stronger for shear and weaker for bending, even the yield point of longitudinal reinforcement is taken as reference point for design. According to this point, a real-life beam is designed and the design steps of the finite element method are discussed.
文摘Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optical system by taking into account the system tasks(i.e., target detection and tracking). We then propose a new non-dominated sorting genetic algorithm(NSGA) to maximize the system surveillance performance. Pareto optimal sets are employed to deal with the conflicts due to the presence of multiple cost functions. Simulation results verify the validity and the improved performance of the proposed technique over benchmark methods.