According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method...According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method of volume fracturing for fan-shaped well pattern is proposed considering the geomechanical modeling, induced stress calculation, hydraulic fracturing simulation, and post-frac productivity evaluation. Besides, we propose the differential fracturing design for the conventional productivity-area and the potential production area for fan-shaped horizontal wells. After the fracturing of the conventional production area for H1 fan-shaped well platform, the research shows that the maximum reduction of the horizontal principal stress difference in the potential productivity-area is 0.2 MPa, which cannot cause the stress reversal, but this reduction is still conducive to the lateral propagation of hydraulic fractures. According to the optimized fracturing design, in zone-Ⅰ of the potential production area, only Well 2 is fractured, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage;in zone-Ⅱ, Well 2 is fractured before Well 3, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage. The swept area of the pore pressure drop in the potential production area is small, showing that the reservoir is not well developed. The hydraulic fracturing in the toe area can be improved by, for example, properly densifying the fractures and adjusting the fracture distribution, in order to enhance the swept volume and increase the reservoir utilization.展开更多
Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output ...Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output (SISO) systems. To solve these problems, an integrated radar and communication system (IRCS) with multiple input multiple output (MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols, pulse repetition frequency (PRF) and length of cyclic prefix (CP). Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases. Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system.展开更多
In the case of the given design variables and constraint functions, this paper is concerned with the rapid overall parameters design of trajectory, propulsion and aerodynamics for long-range ballistic missiles based o...In the case of the given design variables and constraint functions, this paper is concerned with the rapid overall parameters design of trajectory, propulsion and aerodynamics for long-range ballistic missiles based on the index of the minimum take-off mass.In contrast to the traditional subsystem independent design, this paper adopts the research idea of the combination of the subsystem independent design and the multisystem integration design.Firstly, the trajectory, propulsion and aerodynamics of the subsystem are separately designed by the engineering design, including the design of the minimum energy trajectory, the computation of propulsion system parameters, and the calculation of aerodynamic coefficient and dynamic derivative of the missile by employing the software of missile DATCOM. Then, the uniform design method is used to simplify the constraint conditions and the design variables through the integration design, and the accurate design of the optimized variables would be accomplished by adopting the uniform particle swarm optimization(PSO) algorithm. Finally, the automation design software is written for the three-stage solid ballistic missile. The take-off mass of 29 850 kg is derived by the subsystem independent design, and 20 constraints are reduced by employing the uniform design on the basis of 29 design variables and 32 constraints, and the take-off mass is dropped by 1 850 kg by applying the combination of the uniform design and PSO. The simulation results demonstrate the effectiveness and feasibility of the proposed hybrid optimization technique.展开更多
The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience depend...The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method "Bi-Level Integrated System Collaborative Optimization (BLISCO)" is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.展开更多
Some key issues in supporting collaborative design in product data management(PDM ) system and 3D computer aided design(CAD) system integrated environment are analyzed. The general architecture of the integrated e...Some key issues in supporting collaborative design in product data management(PDM ) system and 3D computer aided design(CAD) system integrated environment are analyzed. The general architecture of the integrated environment is divided into five tiers and employs the transparently integrated mode, with the mode, function calling and information exchanging among independent PDM and CAD processes are carried out via message translation /parse approach. Product layout feature(PLF ) model definition is presented, PLF model is used to represent design intention at the preliminary design phase. The collaborative design methodology employing the PLF model in PDM/3D CAD integrated environment is analyzed. The design methodology can speed up the design process, reduce the investment and improve the product quality.展开更多
The basic indexes of all-optical integrated photonic circuits include high-density integration,ultrafast response and ultralow energy consumption.Traditional methods mainly adopt conventional micro/nano-structures.The...The basic indexes of all-optical integrated photonic circuits include high-density integration,ultrafast response and ultralow energy consumption.Traditional methods mainly adopt conventional micro/nano-structures.The overall size of the circuit is large,usually reaches hundreds of microns.Besides,it is difficult to balance the ultrafast response and ultra-low energy consumption problem,and the crosstalk between two traditional devices is difficult to overcome.Here,we propose and experimentally demonstrate an approach based on inverse design method to realize a high-density,ultrafast and ultra-low energy consumption integrated photonic circuit with two all-optical switches controlling the input states of an all-optical XOR logic gate.The feature size of the whole circuit is only 2.5μm×7μm,and that of a single device is 2μm×2μm.The distance between two adjacent devices is as small as 1.5μm,within wavelength magnitude scale.Theoretical response time of the circuit is 150 fs,and the threshold energy is within 10 fJ/bit.We have also considered the crosstalk problem.The circuit also realizes a function of identifying two-digit logic signal results.Our work provides a new idea for the design of ultrafast,ultra-low energy consumption all-optical devices and the implementation of high-density photonic integrated circuits.展开更多
As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude deter...As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude determination.The error influence of different benchmarks and the disintegration mode between the star sensor and the gyro is analyzed in theory.The integrated design of the star sensor and the gyro on the same benchmark can effectively avoid the error influence and improves the spacecraft attitude determination accuracy.Simulation results indicate that when the stars sensor optical axis vectors overlap the reference coordinate axis of the gyro in the same benchmark,the attitude determination accuracy improves.展开更多
As an important element in sustainable building design, the building envelope has been witnessing a constant shift in the design approach. Integrating multi-objective optimization(MOO) into the building envelope desig...As an important element in sustainable building design, the building envelope has been witnessing a constant shift in the design approach. Integrating multi-objective optimization(MOO) into the building envelope design process is very promising, but not easy to realize in an actual project due to several factors, including the complexity of optimization model construction, lack of a dynamic-visualization capacity in the simulation tools and consideration of how to match the optimization with the actual design process. To overcome these difficulties, this study constructed an integrated building envelope design process(IBEDP) based on parametric modelling, which was implemented using Grasshopper platform and interfaces to control the simulation software and optimization algorithm. A railway station was selected as a case study for applying the proposed IBEDP, which also utilized a grid-based variable design approach to achieve flexible optimum fenestrations. To facilitate the stepwise design process, a novel strategy was proposed with a two-step optimization, which optimized various categories of variables separately. Compared with a one-step optimization,though the proposed strategy performed poorly in the diversity of solutions, the quantitative assessment of the qualities of Pareto-optimum solution sets illustrates that it is superior.展开更多
This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oi...This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.展开更多
The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound alg...The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme isproposed to solve this problem. The integrated layout method is applied to re-layout the gear pumpshop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout methodcan concurrently provide good solutions of the cell layouts and the flow path layouts.展开更多
In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called &...In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called "civil aircraft assisted SAGIN(CAA-SAGIN)". The assistance of civil aircrafts can reduce the stress of satellite networks, improve the performance of SAGIN, decrease the construction cost and save space resources. Taking the Chinese mainland as an example, this paper has analyzed the distribution of civil aircrafts, and obtained the coverage characteristics of civil aircraft assisted networks(CAAN). Taking Starlink as the benchmark, this paper has calculated the service gap of CAAN, and designed the joint coverage constellation. The simulation results prove that the number of satellites in CAASAGIN can be greatly reduced with the assistance of civil aircrafts at the same data rate.展开更多
With the accelerated development and utilization of urban underground space,the underground space design of complex based on rail transit has attracted much attention.By sorting out the integration concept and constru...With the accelerated development and utilization of urban underground space,the underground space design of complex based on rail transit has attracted much attention.By sorting out the integration concept and constructing the logical framework of integrated design,the integrated design strategy is proposed from the aspects of function,transportation,space and environment on the urban scale,and the evaluation points of integrated design effect are put forward from the aspects of accessibility,coordination,openness and symbolism.展开更多
The integration of entire supply and value chain into a closed loop network is gaining more importance in recent times in order to ensure a business to be economically and environmentally sustainable with the changing...The integration of entire supply and value chain into a closed loop network is gaining more importance in recent times in order to ensure a business to be economically and environmentally sustainable with the changing trends in business and social environments, growing environmental consciousness in the society and government legislations to protect the environment as well as the business. In this context, this paper considers a multi-echelon closed loop supply chain network design with forward and reverse logistics components. An attempt has been made to develop a mixed integer non-linear programming model for this problem with different costs so that the sum of the total cost is minimized subject to different constraints pertaining to capacities of the entities of the system, demands of first customers and second customers. A generalized model is presented and then its application is illustrated using an example problem by solving the model using LINGO14. This model forms as a tool to compare future meta-heuristics to check the closeness of their solutions with corresponding optimal solutions.展开更多
Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate vario...Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.展开更多
An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating mo...An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance(C_(TI)/C_(BI)).Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.展开更多
Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra d...Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.展开更多
This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architectu...This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architecture of a 3D CAD/PDM integrated system is organized as five tiers. Multi-agent technology is applied with a collaborative design environment. The rule-based product family architecture ( PFA ) and tabular layouts of article characteristics (TLAC) technique are applied to represent the knowledge for product families. They make the knowledge understandable, simplified and can be exchanged among heterogeneous information systems. A transparently concentric integrated mode is put forward to enable the heterogeneous processes to interact and communicate regardless of the language used to construct each process. With the mode, function calling and information exchanging among different processes are carried out via message translation/parse approach. Currently, the integrated system is implemented in the platform of Windows NT and 2000.展开更多
Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- ...Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.展开更多
The authors begin with traditional architectural design methodology,review basic theories and development trends of architectural designs from the ancient times to the present.On the basis of combining traditional ori...The authors begin with traditional architectural design methodology,review basic theories and development trends of architectural designs from the ancient times to the present.On the basis of combining traditional oriental integral view,modern architectural design and landscape design theories,current construction of building facilities in scenic areas are analyzed,integrated design of the building facilities is proposed,and"integrated design system"further analyzed to offer effective references and theoretical support for the design and construction of building facilities in scenic areas.展开更多
Presents the design scheme developed for design of software for Integrated Passive and Active Vibration Control(IPAVC) and the coding of a prototyne system, and the selection of the famous finite element program MSC/N...Presents the design scheme developed for design of software for Integrated Passive and Active Vibration Control(IPAVC) and the coding of a prototyne system, and the selection of the famous finite element program MSC/NASTRAN as an important module of software to deal with large and complicated structures and systems with an example to demonstrate the prototype system.展开更多
基金Supported by National Natural Science Foundation of China (52104029,U2139204)PetroChina Science and Technology Innovation Foundation (2021 DQ02-0501)。
文摘According to the variable toe-to-heel well spacing, combined with the dislocation theory, discrete lattice method, and finite-element-method(FEM) based fluid-solid coupling, an integrated geological-engineering method of volume fracturing for fan-shaped well pattern is proposed considering the geomechanical modeling, induced stress calculation, hydraulic fracturing simulation, and post-frac productivity evaluation. Besides, we propose the differential fracturing design for the conventional productivity-area and the potential production area for fan-shaped horizontal wells. After the fracturing of the conventional production area for H1 fan-shaped well platform, the research shows that the maximum reduction of the horizontal principal stress difference in the potential productivity-area is 0.2 MPa, which cannot cause the stress reversal, but this reduction is still conducive to the lateral propagation of hydraulic fractures. According to the optimized fracturing design, in zone-Ⅰ of the potential production area, only Well 2 is fractured, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage;in zone-Ⅱ, Well 2 is fractured before Well 3, with a cluster spacing of 30 m and an injection rate of 12 m^(3)/min per stage. The swept area of the pore pressure drop in the potential production area is small, showing that the reservoir is not well developed. The hydraulic fracturing in the toe area can be improved by, for example, properly densifying the fractures and adjusting the fracture distribution, in order to enhance the swept volume and increase the reservoir utilization.
基金supported by the National Natural Science Foundation of China(6123101761671352)
文摘Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output (SISO) systems. To solve these problems, an integrated radar and communication system (IRCS) with multiple input multiple output (MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols, pulse repetition frequency (PRF) and length of cyclic prefix (CP). Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases. Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system.
文摘In the case of the given design variables and constraint functions, this paper is concerned with the rapid overall parameters design of trajectory, propulsion and aerodynamics for long-range ballistic missiles based on the index of the minimum take-off mass.In contrast to the traditional subsystem independent design, this paper adopts the research idea of the combination of the subsystem independent design and the multisystem integration design.Firstly, the trajectory, propulsion and aerodynamics of the subsystem are separately designed by the engineering design, including the design of the minimum energy trajectory, the computation of propulsion system parameters, and the calculation of aerodynamic coefficient and dynamic derivative of the missile by employing the software of missile DATCOM. Then, the uniform design method is used to simplify the constraint conditions and the design variables through the integration design, and the accurate design of the optimized variables would be accomplished by adopting the uniform particle swarm optimization(PSO) algorithm. Finally, the automation design software is written for the three-stage solid ballistic missile. The take-off mass of 29 850 kg is derived by the subsystem independent design, and 20 constraints are reduced by employing the uniform design on the basis of 29 design variables and 32 constraints, and the take-off mass is dropped by 1 850 kg by applying the combination of the uniform design and PSO. The simulation results demonstrate the effectiveness and feasibility of the proposed hybrid optimization technique.
基金financially supported by the National Natural Science Foundation of China(Grant No.51109132)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110073120015)
文摘The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method "Bi-Level Integrated System Collaborative Optimization (BLISCO)" is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.
基金Supported by the National High Technology Re-search and Development Programof China(2003AA411011)
文摘Some key issues in supporting collaborative design in product data management(PDM ) system and 3D computer aided design(CAD) system integrated environment are analyzed. The general architecture of the integrated environment is divided into five tiers and employs the transparently integrated mode, with the mode, function calling and information exchanging among independent PDM and CAD processes are carried out via message translation /parse approach. Product layout feature(PLF ) model definition is presented, PLF model is used to represent design intention at the preliminary design phase. The collaborative design methodology employing the PLF model in PDM/3D CAD integrated environment is analyzed. The design methodology can speed up the design process, reduce the investment and improve the product quality.
基金the National Key Research and Development Program of China under Grant No.2018YFB2200403the National Natural Science Foundation of China under Grant Nos.11734001,91950204,92150302.
文摘The basic indexes of all-optical integrated photonic circuits include high-density integration,ultrafast response and ultralow energy consumption.Traditional methods mainly adopt conventional micro/nano-structures.The overall size of the circuit is large,usually reaches hundreds of microns.Besides,it is difficult to balance the ultrafast response and ultra-low energy consumption problem,and the crosstalk between two traditional devices is difficult to overcome.Here,we propose and experimentally demonstrate an approach based on inverse design method to realize a high-density,ultrafast and ultra-low energy consumption integrated photonic circuit with two all-optical switches controlling the input states of an all-optical XOR logic gate.The feature size of the whole circuit is only 2.5μm×7μm,and that of a single device is 2μm×2μm.The distance between two adjacent devices is as small as 1.5μm,within wavelength magnitude scale.Theoretical response time of the circuit is 150 fs,and the threshold energy is within 10 fJ/bit.We have also considered the crosstalk problem.The circuit also realizes a function of identifying two-digit logic signal results.Our work provides a new idea for the design of ultrafast,ultra-low energy consumption all-optical devices and the implementation of high-density photonic integrated circuits.
文摘As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude determination.The error influence of different benchmarks and the disintegration mode between the star sensor and the gyro is analyzed in theory.The integrated design of the star sensor and the gyro on the same benchmark can effectively avoid the error influence and improves the spacecraft attitude determination accuracy.Simulation results indicate that when the stars sensor optical axis vectors overlap the reference coordinate axis of the gyro in the same benchmark,the attitude determination accuracy improves.
基金supported by the National Natural Science Foundation of China (No. 51338006)
文摘As an important element in sustainable building design, the building envelope has been witnessing a constant shift in the design approach. Integrating multi-objective optimization(MOO) into the building envelope design process is very promising, but not easy to realize in an actual project due to several factors, including the complexity of optimization model construction, lack of a dynamic-visualization capacity in the simulation tools and consideration of how to match the optimization with the actual design process. To overcome these difficulties, this study constructed an integrated building envelope design process(IBEDP) based on parametric modelling, which was implemented using Grasshopper platform and interfaces to control the simulation software and optimization algorithm. A railway station was selected as a case study for applying the proposed IBEDP, which also utilized a grid-based variable design approach to achieve flexible optimum fenestrations. To facilitate the stepwise design process, a novel strategy was proposed with a two-step optimization, which optimized various categories of variables separately. Compared with a one-step optimization,though the proposed strategy performed poorly in the diversity of solutions, the quantitative assessment of the qualities of Pareto-optimum solution sets illustrates that it is superior.
文摘This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.
基金This project is supported by National Natural Science Foundation of China (No.59990470)Doctoral Foundation of Ministry of Education, China(No.20010487024).
文摘The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme isproposed to solve this problem. The integrated layout method is applied to re-layout the gear pumpshop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout methodcan concurrently provide good solutions of the cell layouts and the flow path layouts.
基金supported by National Nature Science Foundation of China (No. 61871155)。
文摘In this paper, we propose a novel AIenabled space-air-ground integrated networks(SAGIN). This new integrated networks architecture consists of LEO satellites and civil aircrafts carrying aerial base stations, called "civil aircraft assisted SAGIN(CAA-SAGIN)". The assistance of civil aircrafts can reduce the stress of satellite networks, improve the performance of SAGIN, decrease the construction cost and save space resources. Taking the Chinese mainland as an example, this paper has analyzed the distribution of civil aircrafts, and obtained the coverage characteristics of civil aircraft assisted networks(CAAN). Taking Starlink as the benchmark, this paper has calculated the service gap of CAAN, and designed the joint coverage constellation. The simulation results prove that the number of satellites in CAASAGIN can be greatly reduced with the assistance of civil aircrafts at the same data rate.
文摘With the accelerated development and utilization of urban underground space,the underground space design of complex based on rail transit has attracted much attention.By sorting out the integration concept and constructing the logical framework of integrated design,the integrated design strategy is proposed from the aspects of function,transportation,space and environment on the urban scale,and the evaluation points of integrated design effect are put forward from the aspects of accessibility,coordination,openness and symbolism.
文摘The integration of entire supply and value chain into a closed loop network is gaining more importance in recent times in order to ensure a business to be economically and environmentally sustainable with the changing trends in business and social environments, growing environmental consciousness in the society and government legislations to protect the environment as well as the business. In this context, this paper considers a multi-echelon closed loop supply chain network design with forward and reverse logistics components. An attempt has been made to develop a mixed integer non-linear programming model for this problem with different costs so that the sum of the total cost is minimized subject to different constraints pertaining to capacities of the entities of the system, demands of first customers and second customers. A generalized model is presented and then its application is illustrated using an example problem by solving the model using LINGO14. This model forms as a tool to compare future meta-heuristics to check the closeness of their solutions with corresponding optimal solutions.
基金financially supported by the FDCT Project 0029/2018/A1the University of Macao Research Grants(MYRG2019-00041-ICMS)performed in part at the High-Performance Computing Cluster(HPCC)which is supported by Information and Communication Technology Office(ICTO)of the University of Macao。
文摘Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.
基金Supported by the National Key Research and Development Program of China under Grant No 2017YFA0204600the National Natural Science Foundation of China under Grant No 61404002the Science and Technology Project of Hunan Province under Grant No 2015JC3041
文摘An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors(a-IGZO TFTs)with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance(C_(TI)/C_(BI)).Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.
文摘Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.
基金This paper is supported by National High-Tech Research and Development Plan Foundation in China(2005AA4Z3060) and Electronic Development Fund in 2003.
文摘This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architecture of a 3D CAD/PDM integrated system is organized as five tiers. Multi-agent technology is applied with a collaborative design environment. The rule-based product family architecture ( PFA ) and tabular layouts of article characteristics (TLAC) technique are applied to represent the knowledge for product families. They make the knowledge understandable, simplified and can be exchanged among heterogeneous information systems. A transparently concentric integrated mode is put forward to enable the heterogeneous processes to interact and communicate regardless of the language used to construct each process. With the mode, function calling and information exchanging among different processes are carried out via message translation/parse approach. Currently, the integrated system is implemented in the platform of Windows NT and 2000.
文摘Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.
基金Sponsored by The National Natural Science Fund(51078314)
文摘The authors begin with traditional architectural design methodology,review basic theories and development trends of architectural designs from the ancient times to the present.On the basis of combining traditional oriental integral view,modern architectural design and landscape design theories,current construction of building facilities in scenic areas are analyzed,integrated design of the building facilities is proposed,and"integrated design system"further analyzed to offer effective references and theoretical support for the design and construction of building facilities in scenic areas.
文摘Presents the design scheme developed for design of software for Integrated Passive and Active Vibration Control(IPAVC) and the coding of a prototyne system, and the selection of the famous finite element program MSC/NASTRAN as an important module of software to deal with large and complicated structures and systems with an example to demonstrate the prototype system.