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Multi-agent Based Hierarchy Simulation Models of Carrier-based Aircraft Catapult Launch 被引量:18
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作者 王维军 屈香菊 郭林亮 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第3期223-231,共9页
With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as ... With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system (MAS) is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes. 展开更多
关键词 multi-agent system (MAS) multi-agent based modeling (MABM) TENSOR carrier-based aircraft catapult launch hierarchy simulation model
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DELAY-TIME MODEL BASED ON IMPERFECT INSPECTION OF AIRCRAFT STRUCTURE WITHIN FINITE TIME SPAN 被引量:2
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作者 蔡景 左洪福 朱磊 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第2期159-163,共5页
According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfe... According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model. 展开更多
关键词 aircraft structure delay-time model imperfect inspection optimal maintenance finite time
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IMPROVED AERODYNAMIC APPROXIMATION MODEL WITH CASE-BASED REASONING TECHNIQUE FOR MDO OF AIRCRAFT
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作者 白振东 刘虎 +1 位作者 柴雪 武哲 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第3期187-193,共7页
To increase the efficiency of the multidisciplinary optimization of aircraft, an aerodynamic approximation model is improved. Based on the study of aerodynamic approximation model constructed by the scaling correction... To increase the efficiency of the multidisciplinary optimization of aircraft, an aerodynamic approximation model is improved. Based on the study of aerodynamic approximation model constructed by the scaling correction model, case-based reasoning technique is introduced to improve the approximation model for optimization. The aircraft case model is constructed by utilizing the plane parameters related to aerodynamic characteristics as attributes of cases, and the formula of case retrieving is improved. Finally, the aerodynamic approximation model for optimization is improved by reusing the correction factors of the most similar aircraft to the current one. The multidisciplinary optimization of a civil aircraft concept is carried out with the improved aerodynamic approximation model. The results demonstrate that the precision and the efficiency of the optimization can be improved by utilizing the improved aerodynamic approximation model with ease-based reasoning technique. 展开更多
关键词 aircraft aerodynamic approximation model case-based reasoning multidisciplinary optimization(MDO)
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Modeling of Carrier-based Aircraft Ski Jump Take-off Based on Tensor 被引量:8
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作者 刘伟伟 屈香菊 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2005年第4期326-335,共10页
A general mathematical model of carrier-based aircraft ski jump take-off is derived based on tensor. The carrier, the aircraft body and the movable parts of the landing gears are treated as independent entities. These... A general mathematical model of carrier-based aircraft ski jump take-off is derived based on tensor. The carrier, the aircraft body and the movable parts of the landing gears are treated as independent entities. These entities are assembled into a multi-rigid-body system with flexible links. Dynamical equations of each entity are derived on the basis of the Newton law and the Euler transformation. Using the invariance property of the tensor, the dynamical and kinematical equations are converted to tensor forms which are invariant under time-dependent coordinate transformations. Then the tensor-formed equations are expressed by the matrix operation. Differential equation group of the matrix form is formulated for the programming. The closure of the model is discussed, and the simulation results are given. 展开更多
关键词 mathematical model TENSOR carrier-based aircraft ski jump TAKE-OFF
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Implementation of a Sketch Based Approach to Conceptual Aircraft Design Synthesis and Modeling 被引量:8
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作者 刘虎 武哲 +1 位作者 王钢林 王新林 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2004年第4期207-214,共8页
In the context of applying computer aided design tools to aircraft conceptualdesign, a sketch based approach is proposed to help designers turn their original concepts intocomplex numerical models that are usable for ... In the context of applying computer aided design tools to aircraft conceptualdesign, a sketch based approach is proposed to help designers turn their original concepts intocomplex numerical models that are usable for further analysis and optimization. This approachemphasizes the integration of general configuration and the layout of such components as engines,payloads, fuel tanks and landing gears, and the representation of a design scheme as uniform planesketches and three dimensional models. This paper presents the measures adopted to implement theapproach in a prototype system, including the object-oriented data structure, friendly graphicaluser interfaces and basic features of relevant modules. Several examples generated in the prototypeand applications of the results are finally outlined to illustrate the effectiveness of theapproach. 展开更多
关键词 aircraft conceptual design SKETCH geometric modeling computer aided design
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Modeling Passengers Boarding in Aircraft Using Cellular Automata 被引量:5
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作者 Themistoklis Giitsidis Georgios Ch.Sirakoulis 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI 2016年第4期365-384,共20页
Aircraft are profitable to their owners as long as they are in the air transporting passengers to their destinations;therefore it is vital to minimize as much as possible their preparation time on the ground.In this p... Aircraft are profitable to their owners as long as they are in the air transporting passengers to their destinations;therefore it is vital to minimize as much as possible their preparation time on the ground.In this paper we simulate different boarding strategies with the help of a model based on cellular automata parallel computational tool,attempting to find the most efficient way to deliver each passenger to her/his assigned seat.Two seat arrangements are used,a small one based on Airbus A320/ Boeing 737 and a larger one based on Airbus A380/ Boeing777-300.A wide variety of parameters,including time delay for luggage storing,the frequency by which the passengers enter the plane,different walking speeds of passengers depending on sex,age and height,and the possibility of walking past their seat,are simulated in order to achieve realistic results,as well as monitor their effects on boarding time.The simulation results indicate that the boarding time can be significantly reduced by the simple grouping and prioritizing of passengers.In accordance with previous papers and the examined strategies,the outside-in and reverse pyramid boarding methods outperform all the others for both the small and large airplane seat layout.In the latter,the examined strategies are introduced for first time in an analogous way to the initial small seat arrangement of Airbus A320/ Boeing737 aircraft family.Moreover,since in real world scenarios,the compliance of all the passengers to the suggested group division and boarding strategy cannot be guaranteed,further simulations were conducted.It is clear that as the number of passengers disregarding the priority of the boarding groups increases,the time needed for the boarding to complete tends towards that of the random boarding strategy,thus minimizing the possible advantages gained by the proposed boarding strategies. 展开更多
关键词 Cellular automata aircraft boarding modelING crowd dynamics
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Bayesian-MCMC-based parameter estimation of stealth aircraft RCS models 被引量:2
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作者 夏威 代小霞 冯圆 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期616-622,共7页
When modeling a stealth aircraft with low RCS(Radar Cross Section), conventional parameter estimation methods may cause a deviation from the actual distribution, owing to the fact that the characteristic parameters ... When modeling a stealth aircraft with low RCS(Radar Cross Section), conventional parameter estimation methods may cause a deviation from the actual distribution, owing to the fact that the characteristic parameters are estimated via directly calculating the statistics of RCS. The Bayesian–Markov Chain Monte Carlo(Bayesian-MCMC) method is introduced herein to estimate the parameters so as to improve the fitting accuracies of fluctuation models. The parameter estimations of the lognormal and the Legendre polynomial models are reformulated in the Bayesian framework. The MCMC algorithm is then adopted to calculate the parameter estimates. Numerical results show that the distribution curves obtained by the proposed method exhibit improved consistence with the actual ones, compared with those fitted by the conventional method. The fitting accuracy could be improved by no less than 25% for both fluctuation models, which implies that the Bayesian-MCMC method might be a good candidate among the optimal parameter estimation methods for stealth aircraft RCS models. 展开更多
关键词 stealth aircraft radar cross section fluctuation model Bayesian–Markov Chain Monte Carlo
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Real-Time Four-Dimensional Trajectory Generation Based on Gain-Scheduling Control and a High-Fidelity Aircraft Model 被引量:3
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作者 Olusayo Obajemu Mahdi Mahfouf +3 位作者 Lohithaksha M.Maiyar Abrar Al-Hzndi Michal Weiszer Jun Chen 《Engineering》 SCIE EI 2021年第4期495-506,共12页
Aircraft ground movement plays a key role in improving airport efficiency,as it acts as a link to all other ground operations.Finding novel approaches to coordinate the movements of a fleet of aircraft at an airport i... Aircraft ground movement plays a key role in improving airport efficiency,as it acts as a link to all other ground operations.Finding novel approaches to coordinate the movements of a fleet of aircraft at an airport in order to improve system resilience to disruptions with increasing autonomy is at the center of many key studies for airport airside operations.Moreover,autonomous taxiing is envisioned as a key component in future digitalized airports.However,state-of-the-art routing and scheduling algorithms for airport ground movements do not consider high-fidelity aircraft models at both the proactive and reactive planning phases.The majority of such algorithms do not actively seek to optimize fuel efficiency and reduce harmful greenhouse gas emissions.This paper proposes a new approach for generating efficient four-dimensional trajectories(4DTs)on the basis of a high-fidelity aircraft model and gainscheduling control strategy.Working in conjunction with a routing and scheduling algorithm that determines the taxi route,waypoints,and time deadlines,the proposed approach generates fuel-efficient 4DTs in real time,while respecting operational constraints.The proposed approach can be used in two contexts:①as a reactive decision support tool to generate new trajectories that can resolve unprecedented events;and②as an autopilot system for both partial and fully autonomous taxiing.The proposed methodology is realistic and simple to implement.Moreover,simulation studies show that the proposed approach is capable of providing an up to 11%reduction in the fuel consumed during the taxiing of a large Boeing 747-100 jumbo jet. 展开更多
关键词 aircraft model Intelligent taxiing OPTIMIZATION Four-dimensional trajectory
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Winning Probability Estimation Based on Improved Bradley-Terry Model and Bayesian Network for Aircraft Carrier Battle 被引量:1
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作者 Yuhui Wang Wei Wang Qingxian Wu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第2期39-44,共6页
To provide a decision-making aid for aircraft carrier battle,the winning probability estimation based on Bradley-Terry model and Bayesian network is presented. Firstly,the armed forces units of aircraft carrier are cl... To provide a decision-making aid for aircraft carrier battle,the winning probability estimation based on Bradley-Terry model and Bayesian network is presented. Firstly,the armed forces units of aircraft carrier are classified into three types,which are aircraft,ship and submarine. Then,the attack ability value and defense ability value for each type of armed forces are estimated by using BP neural network,whose training results of sample data are consistent with the estimation results. Next,compared the assessment values through an improved Bradley-Terry model and constructed a Bayesian network to do the global assessment,the winning probabilities of both combat sides are obtained. Finally,the winning probability estimation for a navy battle is given to illustrate the validity of the proposed scheme. 展开更多
关键词 aircraft carrier battle BP neural network Bradley-Terry model Bayesian networks
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Modelling and Backstepping Motion Control of the Aircraft Skin Inspection Robot 被引量:1
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作者 Junjun Jiang Congqing Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第7期105-121,共17页
Aircraft skin health concerns whether the aircraft can fly safely.In this paper,an improved mechanical structure of the aircraft skin inspection robot was introduced.Considering that the aircraft skin surface is a cur... Aircraft skin health concerns whether the aircraft can fly safely.In this paper,an improved mechanical structure of the aircraft skin inspection robot was introduced.Considering that the aircraft skin surface is a curved environment,we assume that the curved environment is equivalent to an inclined plane with a change in inclination.Based on this assumption,the Cartesian dynamics model of the robot is established using the Lagrange method.In order to control the robot’s movement position accurately,a position backstepping control scheme for the aircraft skin inspection robot was presented.According to the dynamic model and taking into account the problems faced by the robot during its movement,a position constrained controller of the aircraft skin inspection robot is designed using the barrier Lyapunov function.Aiming at the disturbances in the robot,we adopt a fuzzy system to approximate the unknown dynamics related with system states.Finally,the simulation results of the designed position constrained controller were compared with the sliding mode controller,and prove the validity of the position constrained controller. 展开更多
关键词 aircraft SKIN inspection robot dynamics modelLING BACKSTEPPING CONTROL fuzzy system barrier LYAPUNOV function motion CONTROL
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Global optimization for ducted coaxial-rotors aircraft based on Kriging model and improved particle swarm optimization algorithm 被引量:1
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作者 杨璐鸿 刘顺安 +1 位作者 张冠宇 王春雪 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1315-1323,共9页
To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example an... To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example and Fluent software was applied to the virtual prototype simulations. Through simulation sample points, the total lift of the ducted coaxial-rotors aircraft was obtained. The Kriging model was then constructed, and the function was fitted. Improved particle swarm optimization(PSO) was also utilized for the global optimization of the Kriging model of the ducted coaxial-rotors aircraft for the determination of optimized global coordinates. Finally, the optimized results were simulated by Fluent. The results show that the Kriging model and the improved PSO algorithm significantly improve the lift performance of ducted coaxial-rotors aircraft and computer operational efficiency. 展开更多
关键词 ducted coaxial rotors aircraft Kriging model particle swarm optimization global optimization
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Hierarchical Colored Timed Petri Nets for Maintenance Process Modeling of Civil Aircraft 被引量:1
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作者 FU Cheng-cheng SUN You-chao LU Zhong 《International Journal of Plant Engineering and Management》 2008年第3期159-166,共8页
Civil aircraft maintenance process simulation model is an effective method for analyzing the maintainability of a civil aircraft. First, we present the Hierarchical Colored Timed Petri Nets for maintenance process mod... Civil aircraft maintenance process simulation model is an effective method for analyzing the maintainability of a civil aircraft. First, we present the Hierarchical Colored Timed Petri Nets for maintenance process modeling of civil aircraft. Then, we expound a general method of civil aircraft maintenance activities, determine the maintenance level for decomposition, and propose the methods of describing logic of relations between the maintenance activities based on Petri Net. Finally, a time Colored Petri multi-level network modeling and simulation procedures and steps are given with the maintenance example of the landing gear burst tire of a certain type of aircraft. The feasibility of the method is proved by the example. 展开更多
关键词 hierarchical timed colored petri nets (HTCPN) civil aircraft maintenance process model MAINTAINABILITY
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A time-optimal aircraft-following model based on Pontryagin's minimum principle 被引量:3
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作者 Linghang MENG Xiaohao XU Zengxian GENG 《Journal of Modern Transportation》 2011年第4期268-273,共6页
A time-optimal aircraft-following model is introduced to address air traffic flow interference by velocity reduction. The objective function is set up as minimizing the recovery time during which the separation minima... A time-optimal aircraft-following model is introduced to address air traffic flow interference by velocity reduction. The objective function is set up as minimizing the recovery time during which the separation minima are not infringed and the separation of the air traffic flow returns to the initial separation at the terminal time. Pontryagin's minimum principle is used to solve the optimum aircraft-following velocity control law. An analytical minimum safe following separation is also provided under the time-optimal control law. The simulation results show that the precision first-order tracking accuracy is achieved without losing the separation. 展开更多
关键词 air traffic flow aircraft-following model time-optimal control safe following separation
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DESIGN OBJECT MODEL AND DESIGN PROCESS MODEL OF COMPUTER AIDED AIRCRAFT CONCEPTUAL DESIGN SYSTEM
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作者 Shen Zhang(Aircraft CAD Research Center, Beijing University of Aeronautics andAstronautics, Beijing, China, 100083) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1995年第3期198-204,共7页
DESIGNOBJECTMODELANDDESIGNPROCESSMODELOFCOMPUTERAIDEDAIRCRAFTCONCEPTUALDESIGNSYSTEMShenZhang(AircraftCADRese... DESIGNOBJECTMODELANDDESIGNPROCESSMODELOFCOMPUTERAIDEDAIRCRAFTCONCEPTUALDESIGNSYSTEMShenZhang(AircraftCADResearchCenter,Beijin... 展开更多
关键词 computer aided design aircraft design models
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Inverse Model Control for a Quad-rotor Aircraft Using TS-fuzzy Support Vector Regression
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作者 Zhiyu Li Hanxin Chen +1 位作者 Congqing Wang Kaijia Xue 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第6期73-79,共7页
An inverse model control based on TS-fuzzy support vector regression( TS-fuzzy SVR) for a quadrotor aircraft is developed. The TS-kernel is the product of linear combination of input and a cluster of output correspond... An inverse model control based on TS-fuzzy support vector regression( TS-fuzzy SVR) for a quadrotor aircraft is developed. The TS-kernel is the product of linear combination of input and a cluster of output corresponding to a cluster of TS-type fuzzy rules. The output of TS-fuzzy SVR is a linear weighted sum of the TSkernels. The dynamical model of the quad-rotor aircraft is derived. A new control scheme combined with TSfuzzy SVR inverse model control and PID control is presented so that the TS-fuzzy SVR inverse model control enhances capabilities of disturbance rejection and the robustness while the PID control enhances fast responsiveness and reliability of the system. Simulation results show the capabilities of the developed control for the attitude system of quad-rotor aircraft. 展开更多
关键词 support vector regression TS-fuzzy SVR INVERSE model CONTROL quad-rotor aircraft ATTITUDE CONTROL
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Refined Aerodynamic Test of Wide-Bodied Aircraft and Its Application 被引量:1
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作者 Dawei Liu Zhiwei Jin +2 位作者 Xin Peng Gang Liu Yue Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期2691-2713,共23页
The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic ... The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft. 展开更多
关键词 Wide-bodied aircraft standard model wind tunnel test REFINEMENT aerodynamic characteristics
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Parametric CAD Modelling of Aircraft Wings for FEA Vibration Analysis
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作者 Shengyong Zhang Mike Mikulich 《Journal of Applied Mathematics and Physics》 2021年第5期889-900,共12页
Excessive vibration of aircraft wings during flight is harmful and may cause propagation of existing cracks in the material, leading to catastrophic failures as a result of material fatigue. This study investigates th... Excessive vibration of aircraft wings during flight is harmful and may cause propagation of existing cracks in the material, leading to catastrophic failures as a result of material fatigue. This study investigates the variations of modal characteristics of aircraft wings with respect to changes in the structural configurations. We develop parametric Computer-Aided Design (CAD) models to capture new design intend on the aircraft wing architectures. Subsequent Finite Element Analysis (FEA) based vibration analysis is performed to study the effects of architecture changes on the wing’s natural frequencies and mode shapes. It is concluded that the spar placement and the number of ribs have significant influence on the wing’s natural vibration properties. Integrating CAD modelling and FEA vibration analysis enables designers to develop alternative wing architectures to implement design requirements in the preliminary design stage. 展开更多
关键词 Parametric modelling CAD aircraft Wings FEA Vibration Analysis
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Modeling and Verification of Aircraft Takeoff Through Novel Quantum Nets
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作者 Maryam Jamal Nazir Ahmad Zafar +3 位作者 Atta-ur-Rahman Dhiaa Musleh Mohammed A.Gollapalli Sghaier Chabani 《Computers, Materials & Continua》 SCIE EI 2022年第8期3331-3348,共18页
The formal modeling and verification of aircraft takeoff is a challenge because it is a complex safety-critical operation.The task of aircraft takeoff is distributed amongst various computer-based controllers,however,... The formal modeling and verification of aircraft takeoff is a challenge because it is a complex safety-critical operation.The task of aircraft takeoff is distributed amongst various computer-based controllers,however,with the growing malicious threats a secure communication between aircraft and controllers becomes highly important.This research serves as a starting point for integration of BB84 quantum protocol with petri nets for secure modeling and verification of takeoff procedure.The integrated model combines the BB84 quantum cryptographic protocol with powerful verification tool support offered by petri nets.To model certain important properties of BB84,a new variant of petri nets coined as Quantum Nets are proposed by defining their mathematical foundations and overall system dynamics,furthermore,some important system properties are also abstractly defined.The proposed QuantumNets are then applied for modeling of aircraft takeoff process by defining three quantum nets:namely aircraft,runway controller and gate controller.For authentication between quantum nets,the use of external places and transitions is demonstrated to describe the encryptiondecryption process of qubits stream.Finally,the developed takeoff quantum network is verified through simulation offered by colored petri-net(CPN)Tools.Moreover,reachability tree(RT)analysis is also performed to have greater confidence in feasibility and correctness of the proposed aircraft takeoff model through the Quantum Nets. 展开更多
关键词 aircraft takeoff BB84 quantum cryptography PETRI-NETS quantum nets formal modeling and verification
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Comparison of aircraft observations with ensemble forecast model results in terms of the microphysical characteristics of stratiform precipitation
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作者 FU Yuan LEI Hengchi +2 位作者 YANG Jiefan GUO Jiaxu ZHU Jiangshan 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第5期452-461,共10页
The prediction of the particle number concentration and liquid/ice water content of cloud is significant for many aspects of atmospheric science.However,given the uncertainties in the initial and boundary conditions a... The prediction of the particle number concentration and liquid/ice water content of cloud is significant for many aspects of atmospheric science.However,given the uncertainties in the initial and boundary conditions and imperfections of microphysical schemes,the accurate prediction of these microphysical properties of cloud is still a big challenge.The ensemble approach may be a viable way to reduce forecast uncertainties.In this paper,a large-scale stratiform cloud precipitation process is studied by comparing results of a 10-member ensemble forecast model with aircraft observation data.By means of the ensemble average,the prediction of bulk parameters such as liquid water content and ice water content can be improved in comparison with the control member,but the particle number concentrations are still one to two orders of magnitude less than those from observations.Intercomparison of raindrop size spectra reveals a big distinction between observations and predictions for particles with a diameter less than 1000μm. 展开更多
关键词 aircraft observation ensemble forecast model particle number concentration liquid/ice water content
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Multi-Domain Parallel Computing for Strength Analysis of Whole Aircraft Model
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作者 Xiuhua Chen Hai Wang Yubo Ding 《Journal of Software Engineering and Applications》 2011年第9期546-549,共4页
In the Windows XP 64 bit operating system environment, several common PC were used to build a cluster system, establishing the distributed memory parallel (DMP) computing system. A finite element model of whole aircra... In the Windows XP 64 bit operating system environment, several common PC were used to build a cluster system, establishing the distributed memory parallel (DMP) computing system. A finite element model of whole aircraft with about 260 million degrees of freedom (DOF) was developed using three-node and four-node thin shell element and two-node beam element. With the large commercial finite element software MSC.MARC and employing two kinds of domain decomposition method (DDM) respectively, realized the parallel solving for the static strength analysis of the whole aircraft model, which offered a high cost-effective solution for solving large-scale and complex finite element models. 展开更多
关键词 Parallel Computing WHOLE aircraft model STATIC Strength DOMAIN DECOMPOSITION
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