Aiming at the issues of poor scalability,single training modes,and missing platform foundation in current parachute training simulation systems,a method for a parachute training simulation system supporting the"1...Aiming at the issues of poor scalability,single training modes,and missing platform foundation in current parachute training simulation systems,a method for a parachute training simulation system supporting the"1+N+N"mode is proposed by building a flexible functional structure design based on four domains and two systems architecture,which can adapt to multiple working modes such as"1+N"and"1+N(*)".This method can effectively save the cost and time of upgrading and expanding system capacity,greatly increasing the lifespan and availability of the system.展开更多
Upper-lower computer mode is the main architecture design of the amphibious combat simulation system(ACSS)at present.Through continuous improvement of real-time performance,software and hardware infrastructure,the exp...Upper-lower computer mode is the main architecture design of the amphibious combat simulation system(ACSS)at present.Through continuous improvement of real-time performance,software and hardware infrastructure,the exponential growth of operational network data scale is realized,but the availability performance of ACSS declines.The reliability of the working host as the key node has become the bottleneck of the overall availability of network nodes in the ACSS.To optimize the network node architecture of ACSS,this paper presents an effective optimization solution by designing the dual redundancy warm-standby module of the mission computer and I/O port,the algorithm of selecting output path of the mission computer in network nodes,the decision-making algorithm upon the on-duty host and output,and the video output decision-making algorithm upon the upper host.Lastly,the complete process of operational data from the input to output and the opposite is implemented well to guarantee the overall availability of network nodes in the ACSS.It has great advantages of wide applicability,strong reliability and high real-time switching speed.展开更多
Service-oriented air combat simulation architecture is proposed.The core design goal is high agility which represents the ability to accommodate the simulation requirements change.Its main idea is to design model unit...Service-oriented air combat simulation architecture is proposed.The core design goal is high agility which represents the ability to accommodate the simulation requirements change.Its main idea is to design model units as services that can communicate and interoperate with any other services at runtime.A service is autonomous and is fully defined by a description contract which contains some combination of syntactic,semantic,and behavioral information.Based on the architecture,air combat simulation system can be described as an abstract composition of description contracts.It becomes concrete at run time as services that implement the constituent description contracts are discovered and bind.The whole process is a continuous run-time activity that responds to simulation needs and the availability of services.This provides benefits of implementation transparency and minimal dependency between models.Thus,simulation system can minimize the impact of change on it and increase the overall efficiency to respond to requirements change.展开更多
Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are g...Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology.展开更多
The development of complex products is essentially concerned with multidisciplinary knowledge. Running on Internet, integration based on muhilayer federation architecture and dynamic reuse of simulation resources are ...The development of complex products is essentially concerned with multidisciplinary knowledge. Running on Internet, integration based on muhilayer federation architecture and dynamic reuse of simulation resources are the major difficulties for complex product collaborative design and simulation. Since the traditional Run-Time Infrastructure (RTI) is not good at supporting these new requirements, an extended high level architecture (HLA) multilayer federation integration architecture (MLFIA), based on the resource management federation (RMF) and its supporting environment based Service-oriented architecture (SOA) and HLA (SOHLA) are proposed, The idea and realization of two key technologies, the dynamic creation of simulation federation based on RMF, TH RTI, an extensible HLA runtime infrastructure (RTI), used at Internet are emphasized. Finally, an industry case about multiple unit (MU) is given.展开更多
Virtual simulation teaching of architecture courses is a teaching mode based on the deep integration of information technology and design class in intelligent environment.Under the background of new engineering,relyin...Virtual simulation teaching of architecture courses is a teaching mode based on the deep integration of information technology and design class in intelligent environment.Under the background of new engineering,relying on a national virtual simulation laboratory,the exploration of green low-carbon simulation in architecture courses is of great importance for improving the dimension of scientific thinking of architecture undergraduates.In this study,based on the background of architecture curriculum construction,the practical content of the teaching reform of architecture courses based on virtual simulation was expounded from three dimensions of reshaping teaching objectives,updating teaching content and improving teaching evaluation.The practical paths of teaching reform of architecture courses were put forward under virtual simulation experiment teaching,namely building teaching teams,strengthening pilot courses,reforming teaching methods,optimizing classroom teaching content and evaluation methods,constructing practical classroom teaching form in line with the learning situation of architecture courses,building a smart learning platform,and closely combining resource construction,application and curriculum content.This study has important practical significance for optimizing and improving the teaching system of professional courses,adapting to the needs of the industry,enhancing competitiveness,and promoting the construction of first-class architecture courses.展开更多
Mega-constellation networks have recently gained significant research attention because of their potential for providing ubiquitous and high-capacity connectivity in future sixth-generation(6G)wireless communication s...Mega-constellation networks have recently gained significant research attention because of their potential for providing ubiquitous and high-capacity connectivity in future sixth-generation(6G)wireless communication systems.However,the high dynamics of network topology and large scale of a megaconstellation pose new challenges to constellation simulation and performance evaluation.To address these issues,we introduce Ultra Star,a high-fidelity and high-efficiency computer simulator to support the development of 6G wireless communication systems with low-Earth-orbit mega-constellation satellites.The simulator facilitates the design and performance analysis of various algorithms and protocols for network operation and deployment.We propose a systematic,scalable,and comprehensive simulation architecture for the high-fidelity modeling of network configurations and for performing highefficiency simulations of network operations and management capabilities,while providing users with intuitive visualizations.We capture heterogeneous topology characteristics by establishing an environment update algorithm that incorporates real ephemeris data for satellite orbit prediction,sun outages,and link handovers.For a realistic simulation of software and hardware configurations,we develop a Network Simulator 3 based network model to support networking protocol extensions.We propose a message passing interface-based parallel and distributed approach with multiple cores or machines to achieve high simulation efficiency in large and complex network scenarios.Experimental results demonstrate the high fidelity and efficiency of Ultra Star can help pave the way for 6G integrated space-ground networks.展开更多
Model-based system-of-systems(SOS)engineering(MBSoSE)is becoming a promising solution for the design of SoS with increasing complexity.However,bridging the models from the design phase to the simulation phase poses si...Model-based system-of-systems(SOS)engineering(MBSoSE)is becoming a promising solution for the design of SoS with increasing complexity.However,bridging the models from the design phase to the simulation phase poses significant challenges and requires an integrated approach.In this study,a unified requirement modeling approach is proposed based on unified architecture framework(UAF).Theoretical models are proposed which compose formalized descriptions from both topdown and bottom-up perspectives.Based on the description,the UAF profile is proposed to represent the SoS mission and constituent systems(CS)goal.Moreover,the agent-based simulation information is also described based on the overview,design concepts,and details(ODD)protocol as the complement part of the SoS profile,which can be transformed into different simulation platforms based on the eXtensible markup language(XML)technology and model-to-text method.In this way,the design of the SoS is simulated automatically in the early design stage.Finally,the method is implemented and an example is given to illustrate the whole process.展开更多
In this study,we simulated the thermal behavior of the mud-brick walls of a Nubian vault.We used EnergyPlus software for the simulation.The results obtained showed that the indoor temperature varies from 25.5℃ to 26....In this study,we simulated the thermal behavior of the mud-brick walls of a Nubian vault.We used EnergyPlus software for the simulation.The results obtained showed that the indoor temperature varies from 25.5℃ to 26.5℃ for the period of January 2018.It varies from 33.2℃ to 33.6℃ with an average value of 33.1℃ for the month of April 2018.For the period of July 2018,it varies from 30.3℃ to 32.2℃ with an average value of 31.2℃..Relative humidity for the period of July ranged from 62.3%to 73.5%,with an average value of 67.9%.The simulation enabled us to compare simulated and measured temperature and humidity values.We found that the level of thermal comfort in the Nubian vault is acceptable in both cool and hot periods.In view of these results,we can say that the Nubian vault is an architecture suited to our climate.The technical concept of the Nubian vault is adapted to the climatic conditions and traditional know-how of the Sahel.We also found that the use of raw earth,a locally available material,and the Nubian vault architectural process,contribute to thermal comfort and a reappropriation of local and adapted know-how.展开更多
In china,many students are unable to do experiments in computer architecture courses,which is very important in helping them to understand many key points.The reason is that the cost of the hardware required is too mu...In china,many students are unable to do experiments in computer architecture courses,which is very important in helping them to understand many key points.The reason is that the cost of the hardware required is too much.Besides,it is very difficult to do research study in hardware experiments.In our course,we adopted an alternative way to deal with the problem: to use software simulators,and designed a set of virtual experiments based on these simulators,which are described in detail in this paper.展开更多
The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel par...The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel parallel scheme for accelerating FDS targeted at multicore architectures.Para-FDS integrates three key optimizations:(1)an adaptive grid partitioning algorithm to enhance scalability,(2)a communication localization optimization approach to reduce overhead between computing nodes,and(3)a NUMA-aware process mapping strategy to improve core utilization within Non-Uniform Memory Access(NUMA)architecture.Implemented on the Tianhe next-generation supercomputer,Para-FDS achieves a speedup of up to 214×on a practical example.It further reduces communication overhead by up to 38%and execution time by up to 22%,significantly improving FDS scalability and efficiency.展开更多
System of systems architecture(SoSA) has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensur...System of systems architecture(SoSA) has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensure requirements have been met.Multiple qualities are discussed in the literature of SoSA evaluation, while research on functionality is scarce. In order to assess SoSA functionality, an extended influence diagram(EID) is developed in this paper. Meanwhile, a simulation method is proposed to elicit the conditional probabilities in EID through designing and executing SoSA. An illustrative anti-missile architecture case is introduced for EID development, architecture design, and simulation.展开更多
Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is ...Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is the retention of genetic diversity of conserved populations in a long-term perspective. However, numerous factors may affect evolution of genetic diversity of a conserved population. Among those factors, the genetic architecture of conserved populations is little considered in current conservation strategies. In this study, we investigated the dynamic changes of genetic diversity of conserved populations with two scenarios on initial genetic architectures by computer simulation in which thirty polymorphic microsatellite loci were chosen to represent genetic architecture of the populations with observed heterozygosity (Ho) and expected heterozygosity (He), observed and mean effective number of alleles (Ao and Ae), number of polymorphic loci (NP) and the percentage of polymorphic loci (PP), number of rare alleles (RA) and number of non-rich polymorphic loci (NRP) as the estimates of genetic diversity. The two scenarios on genetic architecture were taken into account, namely, one conserved population with same allele frequency (AS) and another one with actual allele frequency (AA). The results showed that the magnitude of loss of genetic diversity is associated with genetic architecture of initial conserved population, the amplitude of genetic diversity decline in the context AS was more narrow extent than those in context AA, the ranges of decline of Ho and Ao were about 4 and 2 times in AA compared with that in AS, respectively, the occurrence of first monomorphic locus and the time of change of measure NP in scenario AA is 20 generations and 23 generations earlier than that in scenario AS, respectively. Additionally, we found that NRP, a novel measure proposed by our research group, was a proper estimate for monitoring the evolution of genetic diversity in a closed conserved population. Our study suggested that current managements of conserved populations should emphasize on initial genetic architecture in order to make an effective and feasible conservation scheme.展开更多
Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protoc...Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protocol( AMQP) is proposed to integrate naval distributed tactical training simulation system after serious consideration with current information exchange features of military combat system. Transferring layer in traditional user datagram protocol is implemented by publishing and subscribing scheme of message middleware. By creating message model to standardize message structure,integration architecture is formulated to resolve potential information security risks from inconsistent data type and express data transmission. Meanwhile,a communication model is put forward based on AMQP,which is in the center position of the whole transmission framework and responsible for reliably transferring battlefield data among subsystems. Experiments show that the method can accurately post amounts of data to the subscriber without error and loss,and can get excellent real-time performance of data exchange.展开更多
This paper deals with the modelling and simulation of aircraft systems, in particular for power transmission and control. It is intended to review, propose and disseminate best practices for making model-based/simulat...This paper deals with the modelling and simulation of aircraft systems, in particular for power transmission and control. It is intended to review, propose and disseminate best practices for making model-based/simulation-aided engineering more efficient at any phase of the system life cycle. The proposals are aimed at creating value, not only by increasing the performance of the product under study but also by shortening the time to market, capitalizing knowledge, mitigating risks and facilitating concurrent engineering. The needs associated with the engineering activities are firstly identified to define a set of requirements for the models. Then, these requirements are used to drive the considerations leading to model development, focusing in particular on the process,modelled physical effects, modelling level, model architecting and concurrent engineering. The third part deals with the model implementation, giving special consideration to the different types of models, causalities, parameterization, implementation and verification. Each part is illustrated by examples related to safety critical actuators.展开更多
Large eddy simulation (LES) using the Smagorinsky eddy viscosity model is added to the two-dimensional nine velocity components (D2Q9) lattice Boltzmann equation (LBE) with multi-relaxation-time (MRT) to simul...Large eddy simulation (LES) using the Smagorinsky eddy viscosity model is added to the two-dimensional nine velocity components (D2Q9) lattice Boltzmann equation (LBE) with multi-relaxation-time (MRT) to simulate incompressible turbulent cavity flows with the Reynolds numbers up to 1 × 10^7. To improve the computation efficiency of LBM on the numerical simulations of turbulent flows, the massively parallel computing power from a graphic processing unit (GPU) with a computing unified device architecture (CUDA) is introduced into the MRT-LBE-LES model. The model performs well, compared with the results from others, with an increase of 76 times in computation efficiency. It appears that the higher the Reynolds numbers is, the smaller the Smagorinsky constant should be, if the lattice number is fixed. Also, for a selected high Reynolds number and a selected proper Smagorinsky constant, there is a minimum requirement for the lattice number so that the Smagorinsky eddy viscosity will not be excessively large.展开更多
To improve the agility,dynamics,composability,reusability,and development efficiency restricted by monolithic federation object model(FOM),a modular FOM is proposed by high level architecture(HLA)evolved product devel...To improve the agility,dynamics,composability,reusability,and development efficiency restricted by monolithic federation object model(FOM),a modular FOM is proposed by high level architecture(HLA)evolved product development group.This paper reviews the state-of-the-art of HLA evolved modular FOM.In particular,related concepts,the overall impact on HLA standards,extension principles,and merging processes are discussed.Also permitted and restricted combinations,and merging rules are provided,and the influence on HLA interface specification is given.The comparison between modular FOM and base object model(BOM)is performed to illustrate the importance of their combination.The applications of modular FOM are summarized.Finally,the significance to facilitate compoable simulation both in academia and practice is presented and future directions are pointed out.展开更多
The HLA(high level architecture)-based distributed interactive simulation uses interest management mechanism to reduce the traffic on network and improve the system scalability. Making region updating occur only when ...The HLA(high level architecture)-based distributed interactive simulation uses interest management mechanism to reduce the traffic on network and improve the system scalability. Making region updating occur only when needed can improve the interest management. Typically a static threshold is defined before simulation to trigger the region updating. Now a dynamic threshold is used to trigger region updating , the threshold is adapted by the real-time massage in simulation, named as update lifetime. The result of experiment shows that this policy can overcome the weak point of static threshold and can meet the requirements of bandwidth and simulation correctness.展开更多
In this letter,we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible f...In this letter,we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation,and software/systems engineering. Finally, two specific simulation frameworks are studied as examples.展开更多
To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop(HITL) simulation was employed.HITL simulation methods was classified into three categories,of which the merits an...To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop(HITL) simulation was employed.HITL simulation methods was classified into three categories,of which the merits and shortages were compared.Combing system-in-the-loop(SITL) simulation principle with high level architecture(HLA),an HITL simulation model of asynchronous transfer mode(ATM) network was constructed.The throughput and end-to-end delay of all-digital simulation and HITL simulation was analyzed,which showed that HITL simulation was more reliable and effectively improved the simulation credibility of communication network.Meanwhile,HLA-SITL method was fast and easy to achieve and low-cost during design lifecycle.Thus,it was a feasible way to research and analyze the large-scale network.展开更多
摘要Aiming at the issues of poor scalability,single training modes,and missing platform foundation in current parachute training simulation systems,a method for a parachute training simulation system supporting the"1+N+N"mode is proposed by building a flexible functional structure design based on four domains and two systems architecture,which can adapt to multiple working modes such as"1+N"and"1+N(*)".This method can effectively save the cost and time of upgrading and expanding system capacity,greatly increasing the lifespan and availability of the system.
基金Supported by the National Natural Science Foundation of China(61401496)
摘要Upper-lower computer mode is the main architecture design of the amphibious combat simulation system(ACSS)at present.Through continuous improvement of real-time performance,software and hardware infrastructure,the exponential growth of operational network data scale is realized,but the availability performance of ACSS declines.The reliability of the working host as the key node has become the bottleneck of the overall availability of network nodes in the ACSS.To optimize the network node architecture of ACSS,this paper presents an effective optimization solution by designing the dual redundancy warm-standby module of the mission computer and I/O port,the algorithm of selecting output path of the mission computer in network nodes,the decision-making algorithm upon the on-duty host and output,and the video output decision-making algorithm upon the upper host.Lastly,the complete process of operational data from the input to output and the opposite is implemented well to guarantee the overall availability of network nodes in the ACSS.It has great advantages of wide applicability,strong reliability and high real-time switching speed.
摘要Service-oriented air combat simulation architecture is proposed.The core design goal is high agility which represents the ability to accommodate the simulation requirements change.Its main idea is to design model units as services that can communicate and interoperate with any other services at runtime.A service is autonomous and is fully defined by a description contract which contains some combination of syntactic,semantic,and behavioral information.Based on the architecture,air combat simulation system can be described as an abstract composition of description contracts.It becomes concrete at run time as services that implement the constituent description contracts are discovered and bind.The whole process is a continuous run-time activity that responds to simulation needs and the availability of services.This provides benefits of implementation transparency and minimal dependency between models.Thus,simulation system can minimize the impact of change on it and increase the overall efficiency to respond to requirements change.
基金supported by the National Natural Science Foundation of China(61273198)
摘要Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology.
基金Supported by the National High Technology Research and Development Programme of China (No. 2006AA04Z160).
摘要The development of complex products is essentially concerned with multidisciplinary knowledge. Running on Internet, integration based on muhilayer federation architecture and dynamic reuse of simulation resources are the major difficulties for complex product collaborative design and simulation. Since the traditional Run-Time Infrastructure (RTI) is not good at supporting these new requirements, an extended high level architecture (HLA) multilayer federation integration architecture (MLFIA), based on the resource management federation (RMF) and its supporting environment based Service-oriented architecture (SOA) and HLA (SOHLA) are proposed, The idea and realization of two key technologies, the dynamic creation of simulation federation based on RMF, TH RTI, an extensible HLA runtime infrastructure (RTI), used at Internet are emphasized. Finally, an industry case about multiple unit (MU) is given.
基金the Second Batch of Enterprise-university Cooperative Education Project of the Ministry of Education in 2022(220603608281219)Teacher Education Reform and Teacher Development Research Project of Shaanxi Province in 2023(SJS2023YB040)+3 种基金New Liberal Arts Research and Reform Practice Project of Xi’an University of Science and TechnologyHumanities and Social Science Project of Ministry of Education of China(23YJCZH194)Social Science Foundation of Shaanxi Province,China(2022J052)Natural Science Foundation for Young Scholars of Shaanxi Province,China(2024JC-YBQN-0493).
摘要Virtual simulation teaching of architecture courses is a teaching mode based on the deep integration of information technology and design class in intelligent environment.Under the background of new engineering,relying on a national virtual simulation laboratory,the exploration of green low-carbon simulation in architecture courses is of great importance for improving the dimension of scientific thinking of architecture undergraduates.In this study,based on the background of architecture curriculum construction,the practical content of the teaching reform of architecture courses based on virtual simulation was expounded from three dimensions of reshaping teaching objectives,updating teaching content and improving teaching evaluation.The practical paths of teaching reform of architecture courses were put forward under virtual simulation experiment teaching,namely building teaching teams,strengthening pilot courses,reforming teaching methods,optimizing classroom teaching content and evaluation methods,constructing practical classroom teaching form in line with the learning situation of architecture courses,building a smart learning platform,and closely combining resource construction,application and curriculum content.This study has important practical significance for optimizing and improving the teaching system of professional courses,adapting to the needs of the industry,enhancing competitiveness,and promoting the construction of first-class architecture courses.
基金supported in part by the Major Program of the National Natural Science Foundation of China(62495021 and 62495020)in part by the Natural Sciences and Engineering Research Council of Canada(NSERC)。
摘要Mega-constellation networks have recently gained significant research attention because of their potential for providing ubiquitous and high-capacity connectivity in future sixth-generation(6G)wireless communication systems.However,the high dynamics of network topology and large scale of a megaconstellation pose new challenges to constellation simulation and performance evaluation.To address these issues,we introduce Ultra Star,a high-fidelity and high-efficiency computer simulator to support the development of 6G wireless communication systems with low-Earth-orbit mega-constellation satellites.The simulator facilitates the design and performance analysis of various algorithms and protocols for network operation and deployment.We propose a systematic,scalable,and comprehensive simulation architecture for the high-fidelity modeling of network configurations and for performing highefficiency simulations of network operations and management capabilities,while providing users with intuitive visualizations.We capture heterogeneous topology characteristics by establishing an environment update algorithm that incorporates real ephemeris data for satellite orbit prediction,sun outages,and link handovers.For a realistic simulation of software and hardware configurations,we develop a Network Simulator 3 based network model to support networking protocol extensions.We propose a message passing interface-based parallel and distributed approach with multiple cores or machines to achieve high simulation efficiency in large and complex network scenarios.Experimental results demonstrate the high fidelity and efficiency of Ultra Star can help pave the way for 6G integrated space-ground networks.
基金Fifth Electronic Research Institute of the Ministry of Industry and Information Technology(HK07202200877)Pre-research Project on Civil Aerospace Technologies of CNSA(D020101)+2 种基金Zhejiang Provincial Science and Technology Plan Project(2022C01052)Frontier Scientific Research Program of Deep Space Exploration Laboratory(2022-QYKYJHHXYF-018,2022-QYKYJH-GCXD-001)Zhiyuan Laboratory(ZYL2024001)。
摘要Model-based system-of-systems(SOS)engineering(MBSoSE)is becoming a promising solution for the design of SoS with increasing complexity.However,bridging the models from the design phase to the simulation phase poses significant challenges and requires an integrated approach.In this study,a unified requirement modeling approach is proposed based on unified architecture framework(UAF).Theoretical models are proposed which compose formalized descriptions from both topdown and bottom-up perspectives.Based on the description,the UAF profile is proposed to represent the SoS mission and constituent systems(CS)goal.Moreover,the agent-based simulation information is also described based on the overview,design concepts,and details(ODD)protocol as the complement part of the SoS profile,which can be transformed into different simulation platforms based on the eXtensible markup language(XML)technology and model-to-text method.In this way,the design of the SoS is simulated automatically in the early design stage.Finally,the method is implemented and an example is given to illustrate the whole process.
摘要In this study,we simulated the thermal behavior of the mud-brick walls of a Nubian vault.We used EnergyPlus software for the simulation.The results obtained showed that the indoor temperature varies from 25.5℃ to 26.5℃ for the period of January 2018.It varies from 33.2℃ to 33.6℃ with an average value of 33.1℃ for the month of April 2018.For the period of July 2018,it varies from 30.3℃ to 32.2℃ with an average value of 31.2℃..Relative humidity for the period of July ranged from 62.3%to 73.5%,with an average value of 67.9%.The simulation enabled us to compare simulated and measured temperature and humidity values.We found that the level of thermal comfort in the Nubian vault is acceptable in both cool and hot periods.In view of these results,we can say that the Nubian vault is an architecture suited to our climate.The technical concept of the Nubian vault is adapted to the climatic conditions and traditional know-how of the Sahel.We also found that the use of raw earth,a locally available material,and the Nubian vault architectural process,contribute to thermal comfort and a reappropriation of local and adapted know-how.
摘要In china,many students are unable to do experiments in computer architecture courses,which is very important in helping them to understand many key points.The reason is that the cost of the hardware required is too much.Besides,it is very difficult to do research study in hardware experiments.In our course,we adopted an alternative way to deal with the problem: to use software simulators,and designed a set of virtual experiments based on these simulators,which are described in detail in this paper.
基金supported by the Major Program of Xiangjiang Laboratory(No.22XJ01004)NSFC-FDCT(62361166662)+7 种基金National Key R&D Program of China(2023YFC3503400,2022YFC3400400)The Innovative Research Group Project of Hunan Province(2024JJ1002)Top 10 Technical Key Project in Hunan Province(2023GK1010)Key R&D Program of Hunan Province(2023GK2004,2023SK2059,2023SK2060)Key Technologies R&D Program of Guangdong Province(2023B1111030004)The National Natural Science Foundation of China(41875121,42305170),and the Natural Science Foundation of Hunan Province(2023JJ40678)The Funds of State Key Laboratory of Chemo/Biosensing and Chemometricsthe National Supercomputing Center in Changsha(http://gffzz1c48815de92e4f0bhc5kqqffuw6u669np.ffgz.tsg.suse.edu.cn/),and Peng Cheng Lab.
摘要The Fire Dynamics Simulator(FDS)is widely used for fire simulation but faces scalability challenges due to its limited grid partitioning capabilities.To address this issue,we propose Para-FDS,a scalable multilevel parallel scheme for accelerating FDS targeted at multicore architectures.Para-FDS integrates three key optimizations:(1)an adaptive grid partitioning algorithm to enhance scalability,(2)a communication localization optimization approach to reduce overhead between computing nodes,and(3)a NUMA-aware process mapping strategy to improve core utilization within Non-Uniform Memory Access(NUMA)architecture.Implemented on the Tianhe next-generation supercomputer,Para-FDS achieves a speedup of up to 214×on a practical example.It further reduces communication overhead by up to 38%and execution time by up to 22%,significantly improving FDS scalability and efficiency.
基金supported by the National Natural Science Foundation of China(71571189)
摘要System of systems architecture(SoSA) has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensure requirements have been met.Multiple qualities are discussed in the literature of SoSA evaluation, while research on functionality is scarce. In order to assess SoSA functionality, an extended influence diagram(EID) is developed in this paper. Meanwhile, a simulation method is proposed to elicit the conditional probabilities in EID through designing and executing SoSA. An illustrative anti-missile architecture case is introduced for EID development, architecture design, and simulation.
基金partly supported by the program for Changjiang Scholar and Innovation Research Team in University, China (IRT1191)the Beijing Science and Technology Project, China (Z080005022208015)the Chinese Universities Scientific Fund (2012YJ058)
摘要Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is the retention of genetic diversity of conserved populations in a long-term perspective. However, numerous factors may affect evolution of genetic diversity of a conserved population. Among those factors, the genetic architecture of conserved populations is little considered in current conservation strategies. In this study, we investigated the dynamic changes of genetic diversity of conserved populations with two scenarios on initial genetic architectures by computer simulation in which thirty polymorphic microsatellite loci were chosen to represent genetic architecture of the populations with observed heterozygosity (Ho) and expected heterozygosity (He), observed and mean effective number of alleles (Ao and Ae), number of polymorphic loci (NP) and the percentage of polymorphic loci (PP), number of rare alleles (RA) and number of non-rich polymorphic loci (NRP) as the estimates of genetic diversity. The two scenarios on genetic architecture were taken into account, namely, one conserved population with same allele frequency (AS) and another one with actual allele frequency (AA). The results showed that the magnitude of loss of genetic diversity is associated with genetic architecture of initial conserved population, the amplitude of genetic diversity decline in the context AS was more narrow extent than those in context AA, the ranges of decline of Ho and Ao were about 4 and 2 times in AA compared with that in AS, respectively, the occurrence of first monomorphic locus and the time of change of measure NP in scenario AA is 20 generations and 23 generations earlier than that in scenario AS, respectively. Additionally, we found that NRP, a novel measure proposed by our research group, was a proper estimate for monitoring the evolution of genetic diversity in a closed conserved population. Our study suggested that current managements of conserved populations should emphasize on initial genetic architecture in order to make an effective and feasible conservation scheme.
基金Supported by the National Natural Science Foundation of China(No.61401496)
摘要Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protocol( AMQP) is proposed to integrate naval distributed tactical training simulation system after serious consideration with current information exchange features of military combat system. Transferring layer in traditional user datagram protocol is implemented by publishing and subscribing scheme of message middleware. By creating message model to standardize message structure,integration architecture is formulated to resolve potential information security risks from inconsistent data type and express data transmission. Meanwhile,a communication model is put forward based on AMQP,which is in the center position of the whole transmission framework and responsible for reliably transferring battlefield data among subsystems. Experiments show that the method can accurately post amounts of data to the subscriber without error and loss,and can get excellent real-time performance of data exchange.
摘要This paper deals with the modelling and simulation of aircraft systems, in particular for power transmission and control. It is intended to review, propose and disseminate best practices for making model-based/simulation-aided engineering more efficient at any phase of the system life cycle. The proposals are aimed at creating value, not only by increasing the performance of the product under study but also by shortening the time to market, capitalizing knowledge, mitigating risks and facilitating concurrent engineering. The needs associated with the engineering activities are firstly identified to define a set of requirements for the models. Then, these requirements are used to drive the considerations leading to model development, focusing in particular on the process,modelled physical effects, modelling level, model architecting and concurrent engineering. The third part deals with the model implementation, giving special consideration to the different types of models, causalities, parameterization, implementation and verification. Each part is illustrated by examples related to safety critical actuators.
基金supported by College of William and Mary,Virginia Institute of Marine Science for the study environment
摘要Large eddy simulation (LES) using the Smagorinsky eddy viscosity model is added to the two-dimensional nine velocity components (D2Q9) lattice Boltzmann equation (LBE) with multi-relaxation-time (MRT) to simulate incompressible turbulent cavity flows with the Reynolds numbers up to 1 × 10^7. To improve the computation efficiency of LBM on the numerical simulations of turbulent flows, the massively parallel computing power from a graphic processing unit (GPU) with a computing unified device architecture (CUDA) is introduced into the MRT-LBE-LES model. The model performs well, compared with the results from others, with an increase of 76 times in computation efficiency. It appears that the higher the Reynolds numbers is, the smaller the Smagorinsky constant should be, if the lattice number is fixed. Also, for a selected high Reynolds number and a selected proper Smagorinsky constant, there is a minimum requirement for the lattice number so that the Smagorinsky eddy viscosity will not be excessively large.
基金supported by the National Natural Science Foundation of China(6067406960574056).
摘要To improve the agility,dynamics,composability,reusability,and development efficiency restricted by monolithic federation object model(FOM),a modular FOM is proposed by high level architecture(HLA)evolved product development group.This paper reviews the state-of-the-art of HLA evolved modular FOM.In particular,related concepts,the overall impact on HLA standards,extension principles,and merging processes are discussed.Also permitted and restricted combinations,and merging rules are provided,and the influence on HLA interface specification is given.The comparison between modular FOM and base object model(BOM)is performed to illustrate the importance of their combination.The applications of modular FOM are summarized.Finally,the significance to facilitate compoable simulation both in academia and practice is presented and future directions are pointed out.
摘要The HLA(high level architecture)-based distributed interactive simulation uses interest management mechanism to reduce the traffic on network and improve the system scalability. Making region updating occur only when needed can improve the interest management. Typically a static threshold is defined before simulation to trigger the region updating. Now a dynamic threshold is used to trigger region updating , the threshold is adapted by the real-time massage in simulation, named as update lifetime. The result of experiment shows that this policy can overcome the weak point of static threshold and can meet the requirements of bandwidth and simulation correctness.
基金Project (Nos.60574056 and 60674069) supported by the National Natural Science Foundation of China
摘要In this letter,we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation,and software/systems engineering. Finally, two specific simulation frameworks are studied as examples.
基金Supported by the National Natural Science Foundation of China (61101129)Specialized Research Fund for the Doctoral Program of Higher Education(20091101110019)
摘要To enhance the fidelity and accuracy of the simulation of communication networks,hardware-in-the-loop(HITL) simulation was employed.HITL simulation methods was classified into three categories,of which the merits and shortages were compared.Combing system-in-the-loop(SITL) simulation principle with high level architecture(HLA),an HITL simulation model of asynchronous transfer mode(ATM) network was constructed.The throughput and end-to-end delay of all-digital simulation and HITL simulation was analyzed,which showed that HITL simulation was more reliable and effectively improved the simulation credibility of communication network.Meanwhile,HLA-SITL method was fast and easy to achieve and low-cost during design lifecycle.Thus,it was a feasible way to research and analyze the large-scale network.