In this paper,a methodology for designing mooring system deployment for vessels at varying water depths is proposed.The Non-dominated Sorting Genetic Algorithm-II(NSGA-II)is combined with a self-dependently developed ...In this paper,a methodology for designing mooring system deployment for vessels at varying water depths is proposed.The Non-dominated Sorting Genetic Algorithm-II(NSGA-II)is combined with a self-dependently developed vessel-mooring coupled program to find the optimal mooring system deployment considering both station-keeping requirements and the safety of the mooring system.Two case studies are presented to demonstrate the methodology by designing the mooring system deployments for a very large floating structure(VLFS)module and a semi-submersible platform respectively at three different water depths.It can be concluded from the obtained results that the mooring system can achieve a better station-keeping ability with relatively shorter mooring line when deployed in the shallow water.The safety factor of mooring line is mainly dominated by the maximum instantaneous tension increment in the shallow water,while the pre-tension has a decisive influence on the safety factor of the mooring line in the deep water.展开更多
The Godson-2G microprocessor is a high performance SOC which integrates a four-issue 64-bit high performance CPU core (called GS464), a DDR2/3 controller, a HyperTransport controller, a PCI/PCI-X controller, etc. It...The Godson-2G microprocessor is a high performance SOC which integrates a four-issue 64-bit high performance CPU core (called GS464), a DDR2/3 controller, a HyperTransport controller, a PCI/PCI-X controller, etc. It is physically implemented in 65 nm CMOS process and reaches the frequency of 1GHz with power consumption less than 4 W. The main challenges of Godson-2G physical implementation include nanometer process technology effects, high performance design targets, and tight schedule. This paper describes the key innovative features of physical design methodology which had been used in Godson-2G physical implementation, with particular emphasis on interconnect driven floorplan generation (ICD-FP), adapted boundary constraints design optimization (ABC-OPT), automatic register group clock tree generation methodology (ARG-CTS).展开更多
This paper deals with a design methodology of permanent magnets(PM)generators used for fixed-pitch tidal turbines in a marine renewable energy context.In the case of underwater turbines,fixed-pitch tidal turbines coul...This paper deals with a design methodology of permanent magnets(PM)generators used for fixed-pitch tidal turbines in a marine renewable energy context.In the case of underwater turbines,fixed-pitch tidal turbines could be very attractive and interesting to reduce maintenance operation by avoiding using such a complex electromechanical system for blade-pitching.In this technological case,one of the main control challenges is to ensure power limitation at high tidal current velocities.This control mode can be achieved using the generator flux-weakening.In this context,this paper proposes an original and systemic design methodology to optimize the generator design taking into account the tidal turbine power limitation for high tidal currents velocities.展开更多
This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding verti...This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and stiffness.Testing involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the control.Failures typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.展开更多
The planned missions to explore the surfaces of the Moon and Mars require high exploration efficiency,thus imposing new demands on the mobility system of planetary rovers.In this paper,a design method for a high-speed...The planned missions to explore the surfaces of the Moon and Mars require high exploration efficiency,thus imposing new demands on the mobility system of planetary rovers.In this paper,a design method for a high-speed planetary rover(HPR)is proposed,and the representative configurations are modeled and simulated.First,the influence of the planetary surface environment on the design of HPRs is analyzed,and the design factors for HPRs are determined by studying a single-wheel suspension.Second,a design methodology for HPRs is proposed.The adaptive suspension mechanisms of a four-wheeled rover are synthesized using the all-wheel-attachment condition and position and orientation characteristics theory,which are expressed in the form of a graph theory for the increase in elastic components and active joints.Finally,a dynamic model is built,and a simulation is carried out for the proposed rover.The validity of the proposed method and rover is verified,thus highlighting their potential application in future planetary exploration.展开更多
This paper systematically evaluates and compares three well-engineered and popular multi-objective optimization algorithms for the design of switched reluctance machines.The multi-physics and multi-objective nature of...This paper systematically evaluates and compares three well-engineered and popular multi-objective optimization algorithms for the design of switched reluctance machines.The multi-physics and multi-objective nature of electric machine design problems are discussed,followed by benchmark studies comparing generic algorithms(GA),differential evolution(DE)algorithms and particle swarm optimizations(PSO)on a 6/4 switched reluctance machine design with seven independent variables and a strong nonlinear multi-objective Pareto front.To better quantify the quality of the Pareto fronts,five primary quality indicators are employed to serve as the algorithm testing metrics.The results show that the three algorithms have similar performances when the optimization employs only a small number of candidate designs or ultimately,a significant amount of candidate designs.However,DE tends to perform better in terms of convergence speed and the quality of Pareto front when a relatively modest amount of candidates are considered.展开更多
A design methodology for multi-agent systems is proposed. The systemicframework of CAPP and scheduling integrated multi-agent system according to design methodology isresearched. Agent model, composition model and coo...A design methodology for multi-agent systems is proposed. The systemicframework of CAPP and scheduling integrated multi-agent system according to design methodology isresearched. Agent model, composition model and cooperation model are discussed respectively in themulti-agent system. Static composition model and dynamic running model of CAPP and schedulingintegrated system are presented in composition model. Communication model, language model andprotocol model are discussed in corporation model. CSIMAS, CAPP and scheduling integratedmulti-agent prototype system, is developed to illuminate system model. Multiple non-rotational partsare tested in distributed process planning and scheduling environment of CSIMAS.展开更多
This paper overviews design for manufacturing (DFM) for IC design in nano-CMOS technologies. Process/device issues relevant to the manufacturability of ICs in advanced CMOS technologies will be presented first befor...This paper overviews design for manufacturing (DFM) for IC design in nano-CMOS technologies. Process/device issues relevant to the manufacturability of ICs in advanced CMOS technologies will be presented first before an exploration on process/device modeling for DFM is done. The discussion also covers a brief introduction of DFM-aware of design flow and EDA efforts to better handle the design-manufacturing interface in very large scale IC design environment.展开更多
The present study introduces an innovative aerodynamic redesign of an axial flow fan based on constant diffusion factor and radial equilibrium.All input design parameters such as mass flow rate,hub to tip ratio,aspect...The present study introduces an innovative aerodynamic redesign of an axial flow fan based on constant diffusion factor and radial equilibrium.All input design parameters such as mass flow rate,hub to tip ratio,aspect ratio,tip diameter and angular velocity are taken from NASA Rotor 67 as a conventional axial flow fan.A computer program is developed to extract the three-dimensional geometry of a fan and to estimate the span-wise distribution of parameters.The new designed fan flow field is investigated in detail by CFD tool at both design and off design conditions.Finally,a turbofan cycle analysis is conducted based on thermodynamic and gas dynamic principles to evaluate the fan performance in a turbofan engine in comparison to NASA Rotor 67.Achieving a higher total pressure ratio,meeting the target pressure ratio in lower rotational speed with higher efficiency,delivering more bypass air in a constant diameter and less fuel consumption for the same specific thrust force are the main advantages for the new design strategy in comparison to the conventional designed fans such as Rotor 67.However,efficiency reduction in fan over speed is the main disadvantage.展开更多
Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly...Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09 mg/L/hr.Temperature, p H, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model(R^2= 0.9821) being obtained, the highest biodegradation efficiency of 19.03 mg/L/hr was reached compared to previous reports under the optimal conditions(30.71°C, pH 7.14, 4.23%(V/V) inoculum size and 157.1 mg/L initial atrazine concentration).Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.展开更多
The Godson-3A microprocessor is a quad-core version of the scalable Godson-3 multi-core series. It is physically implemented based on the 65 nm CMOS process. This 174 mm2 chip consists of 425 million transistors. The ...The Godson-3A microprocessor is a quad-core version of the scalable Godson-3 multi-core series. It is physically implemented based on the 65 nm CMOS process. This 174 mm2 chip consists of 425 million transistors. The maximum frequency is 1GHz with a maximum power consumption of 15 W. The main challenges of Godson-3A physical implementation include very large scale, high frequency requirement, sub-micron technology effects and aggressive time schedule. This paper describes the design methodology of the physical implementation of Godson-3A, with particular emphasis on design methods for high frequency, clock tree design, power management, and on-chip variation (OCV) issue.展开更多
Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite fer...Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite ferroelectrics,were widely employed to fabricate dielectric capacitors from 1950s.Since a piezoelectric breakthrough was achieved via chemical modification,intensive researches have been performed embracing lead-free BT-based piezoelectrics and their extensional functionalities.In this review,we encompass the stateof-the-art progress on chemical modification tuning phase structure toward advanced electrical properties in BT-based ceramics.Generally,modulated regularity of cations substitution on phase transition is summarized and clarified.Then,we highlight the common methodologies of phase structure(phase boundary,relaxor phase,room-temperature phase transition,etc.)design for optimizing piezoelectricity,electrostrictive strain,electrocaloric,dielectric energy storage or permittivity performances,and cover the noticeable developments and relevant physical mechanisms.Finally,perspectives and challenges on future research issues are featured.This review proposes to exert the significant guidance and service for material design of BT-based and other lead-free perovskite materials with superior functionalities.展开更多
A set of semiconductor laser pulse seed sources based on an embedded chip is proposed.The greatest feature is that the optical pulse frequency and width can be independently adjusted in real time.The pulse seed source...A set of semiconductor laser pulse seed sources based on an embedded chip is proposed.The greatest feature is that the optical pulse frequency and width can be independently adjusted in real time.The pulse seed sources can be switched independently and online from the gain-switched mode to the quasi-continuous wave mode to obtain optimal optical parameters for specific applications.To explore the physical mechanism of the semiconductor laser source,the rate equation that describes the carrier-photon transient change in a semiconductor laser cavity is numerically derived and solved.Subsequently,problems that need to be considered while designing the drive circuit are identified.The system evaluation indicates that the optical pulse frequency adjustment range is 250 Hz to 42 MHz,and the narrowest optical pulse output width is 80 ps.The pulse seed source can drive semiconductor lasers with different central wavelengths(1064,1550,and 1970 nm),and can also simultaneously drive two semiconductor lasers and output dual-band optical pulses.It can be used as a seed source for general high-power optical systems,and exhibits good application value and extensive market prospects.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51709170 and 51979167)the Ministry of Industry and Information Technology of China(Mooring position technology:floating support platform engineering(II))the Shanghai Sailing Program(Grant No.17YF1409700)
文摘In this paper,a methodology for designing mooring system deployment for vessels at varying water depths is proposed.The Non-dominated Sorting Genetic Algorithm-II(NSGA-II)is combined with a self-dependently developed vessel-mooring coupled program to find the optimal mooring system deployment considering both station-keeping requirements and the safety of the mooring system.Two case studies are presented to demonstrate the methodology by designing the mooring system deployments for a very large floating structure(VLFS)module and a semi-submersible platform respectively at three different water depths.It can be concluded from the obtained results that the mooring system can achieve a better station-keeping ability with relatively shorter mooring line when deployed in the shallow water.The safety factor of mooring line is mainly dominated by the maximum instantaneous tension increment in the shallow water,while the pre-tension has a decisive influence on the safety factor of the mooring line in the deep water.
基金Supported by the National High Technology Research and Development 863 Program of China under Grant No.2007AA01Z114.
文摘The Godson-2G microprocessor is a high performance SOC which integrates a four-issue 64-bit high performance CPU core (called GS464), a DDR2/3 controller, a HyperTransport controller, a PCI/PCI-X controller, etc. It is physically implemented in 65 nm CMOS process and reaches the frequency of 1GHz with power consumption less than 4 W. The main challenges of Godson-2G physical implementation include nanometer process technology effects, high performance design targets, and tight schedule. This paper describes the key innovative features of physical design methodology which had been used in Godson-2G physical implementation, with particular emphasis on interconnect driven floorplan generation (ICD-FP), adapted boundary constraints design optimization (ABC-OPT), automatic register group clock tree generation methodology (ARG-CTS).
文摘This paper deals with a design methodology of permanent magnets(PM)generators used for fixed-pitch tidal turbines in a marine renewable energy context.In the case of underwater turbines,fixed-pitch tidal turbines could be very attractive and interesting to reduce maintenance operation by avoiding using such a complex electromechanical system for blade-pitching.In this technological case,one of the main control challenges is to ensure power limitation at high tidal current velocities.This control mode can be achieved using the generator flux-weakening.In this context,this paper proposes an original and systemic design methodology to optimize the generator design taking into account the tidal turbine power limitation for high tidal currents velocities.
文摘This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and stiffness.Testing involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the control.Failures typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51521003)the National Natural Science Foundation of China(Grant Nos.51975140,52005122)+1 种基金the“111”Project of China(Grant No.B07018)the Harbin Institute of Technology Key Project Research and Development Grant of China(Grant No.HIT2021005).
文摘The planned missions to explore the surfaces of the Moon and Mars require high exploration efficiency,thus imposing new demands on the mobility system of planetary rovers.In this paper,a design method for a high-speed planetary rover(HPR)is proposed,and the representative configurations are modeled and simulated.First,the influence of the planetary surface environment on the design of HPRs is analyzed,and the design factors for HPRs are determined by studying a single-wheel suspension.Second,a design methodology for HPRs is proposed.The adaptive suspension mechanisms of a four-wheeled rover are synthesized using the all-wheel-attachment condition and position and orientation characteristics theory,which are expressed in the form of a graph theory for the increase in elastic components and active joints.Finally,a dynamic model is built,and a simulation is carried out for the proposed rover.The validity of the proposed method and rover is verified,thus highlighting their potential application in future planetary exploration.
文摘This paper systematically evaluates and compares three well-engineered and popular multi-objective optimization algorithms for the design of switched reluctance machines.The multi-physics and multi-objective nature of electric machine design problems are discussed,followed by benchmark studies comparing generic algorithms(GA),differential evolution(DE)algorithms and particle swarm optimizations(PSO)on a 6/4 switched reluctance machine design with seven independent variables and a strong nonlinear multi-objective Pareto front.To better quantify the quality of the Pareto fronts,five primary quality indicators are employed to serve as the algorithm testing metrics.The results show that the three algorithms have similar performances when the optimization employs only a small number of candidate designs or ultimately,a significant amount of candidate designs.However,DE tends to perform better in terms of convergence speed and the quality of Pareto front when a relatively modest amount of candidates are considered.
文摘A design methodology for multi-agent systems is proposed. The systemicframework of CAPP and scheduling integrated multi-agent system according to design methodology isresearched. Agent model, composition model and cooperation model are discussed respectively in themulti-agent system. Static composition model and dynamic running model of CAPP and schedulingintegrated system are presented in composition model. Communication model, language model andprotocol model are discussed in corporation model. CSIMAS, CAPP and scheduling integratedmulti-agent prototype system, is developed to illuminate system model. Multiple non-rotational partsare tested in distributed process planning and scheduling environment of CSIMAS.
基金the National Natural Science Foundation of China (Grant No. 60736030)
文摘This paper overviews design for manufacturing (DFM) for IC design in nano-CMOS technologies. Process/device issues relevant to the manufacturability of ICs in advanced CMOS technologies will be presented first before an exploration on process/device modeling for DFM is done. The discussion also covers a brief introduction of DFM-aware of design flow and EDA efforts to better handle the design-manufacturing interface in very large scale IC design environment.
文摘The present study introduces an innovative aerodynamic redesign of an axial flow fan based on constant diffusion factor and radial equilibrium.All input design parameters such as mass flow rate,hub to tip ratio,aspect ratio,tip diameter and angular velocity are taken from NASA Rotor 67 as a conventional axial flow fan.A computer program is developed to extract the three-dimensional geometry of a fan and to estimate the span-wise distribution of parameters.The new designed fan flow field is investigated in detail by CFD tool at both design and off design conditions.Finally,a turbofan cycle analysis is conducted based on thermodynamic and gas dynamic principles to evaluate the fan performance in a turbofan engine in comparison to NASA Rotor 67.Achieving a higher total pressure ratio,meeting the target pressure ratio in lower rotational speed with higher efficiency,delivering more bypass air in a constant diameter and less fuel consumption for the same specific thrust force are the main advantages for the new design strategy in comparison to the conventional designed fans such as Rotor 67.However,efficiency reduction in fan over speed is the main disadvantage.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2012ZX07212001)the National Natural Science Foundation of China(No.31570505)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.2014TS05)
文摘Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09 mg/L/hr.Temperature, p H, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model(R^2= 0.9821) being obtained, the highest biodegradation efficiency of 19.03 mg/L/hr was reached compared to previous reports under the optimal conditions(30.71°C, pH 7.14, 4.23%(V/V) inoculum size and 157.1 mg/L initial atrazine concentration).Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.
基金supported by the National Basic Research 973 Program of China under Grant No.2005CB321600the National High Technology Research & Development 863 Program of China under Grant Nos.2008AA110901,2009AA01Z125 and 2007AA01Z114the National Natural Science Foundation of China under Grant Nos.60803029,60673146,60736012.
文摘The Godson-3A microprocessor is a quad-core version of the scalable Godson-3 multi-core series. It is physically implemented based on the 65 nm CMOS process. This 174 mm2 chip consists of 425 million transistors. The maximum frequency is 1GHz with a maximum power consumption of 15 W. The main challenges of Godson-3A physical implementation include very large scale, high frequency requirement, sub-micron technology effects and aggressive time schedule. This paper describes the design methodology of the physical implementation of Godson-3A, with particular emphasis on design methods for high frequency, clock tree design, power management, and on-chip variation (OCV) issue.
基金Key Technologies Research and Development Program of Sichuan Province,Grant/Award Number:2018JY0007National Natural Science Foundation of China,Grant/Award Number:51722208。
文摘Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives.Barium titanate(BaTiO3,BT)ceramics,the first discovered perovskite ferroelectrics,were widely employed to fabricate dielectric capacitors from 1950s.Since a piezoelectric breakthrough was achieved via chemical modification,intensive researches have been performed embracing lead-free BT-based piezoelectrics and their extensional functionalities.In this review,we encompass the stateof-the-art progress on chemical modification tuning phase structure toward advanced electrical properties in BT-based ceramics.Generally,modulated regularity of cations substitution on phase transition is summarized and clarified.Then,we highlight the common methodologies of phase structure(phase boundary,relaxor phase,room-temperature phase transition,etc.)design for optimizing piezoelectricity,electrostrictive strain,electrocaloric,dielectric energy storage or permittivity performances,and cover the noticeable developments and relevant physical mechanisms.Finally,perspectives and challenges on future research issues are featured.This review proposes to exert the significant guidance and service for material design of BT-based and other lead-free perovskite materials with superior functionalities.
基金Project supported by the Basic Research Foundation of Knowledge Innovation Program of Shenzhen City,China(No.JCYJ20180301-171044707)the University-Enterprise Cooperation Research and Development Project of Shenzhen Technology University,China(Nos.2018010802002,2018010802005,and 2019310103001)。
文摘A set of semiconductor laser pulse seed sources based on an embedded chip is proposed.The greatest feature is that the optical pulse frequency and width can be independently adjusted in real time.The pulse seed sources can be switched independently and online from the gain-switched mode to the quasi-continuous wave mode to obtain optimal optical parameters for specific applications.To explore the physical mechanism of the semiconductor laser source,the rate equation that describes the carrier-photon transient change in a semiconductor laser cavity is numerically derived and solved.Subsequently,problems that need to be considered while designing the drive circuit are identified.The system evaluation indicates that the optical pulse frequency adjustment range is 250 Hz to 42 MHz,and the narrowest optical pulse output width is 80 ps.The pulse seed source can drive semiconductor lasers with different central wavelengths(1064,1550,and 1970 nm),and can also simultaneously drive two semiconductor lasers and output dual-band optical pulses.It can be used as a seed source for general high-power optical systems,and exhibits good application value and extensive market prospects.