AsiaSim 2013

An efficient simulation execution engine is crucial for agent-based traffic simulation. Depending on the size of the simulation scenario the execution engine would have to update several thousand agents during a single time step. This update may also include route calculations which are computationally expensive. The ability to dynamically re-calculate the route of agents is a feature often not required in classical microscopic traffic simulations. However, for the agent-based traffic simulation which is part of the Scalable Electro-Mobility Simulation (SEMSim) platform, the routing ability of agents is an important feature. In this paper, we describe a multi-threaded simulation engine that explicitly supports routing capabilities for every agent. In addition, we analyse the efficiency and performance of our execution model in the context of a Singapore-based simulation scenario.

As the processor has entered the multi-core/many-core era, the parallel processing capability of a single processor can be improved in scale with increasing cores. However, for the high performance computation (HPC) clusters, the improvement of inter-node communication latency is far behind of the performance improvement of processors. As a result, communication latency often becomes the performance bottleneck of most HPC applications. This paper focuses on solving the communication latency problem of adjacent inter-action simulation on multi-core/many-core clusters, and pro-poses an optimized algorithm for adjacent interaction simula-tion on modern general purpose graphic many-core architec-tures and an O(B+2R) algorithm for inter-node latency-hiding. The theoretical analysis and experimental result show that the techniques proposed in this paper can effectively improve the performance of adjacent interaction simulation on multi-core/many-core clusters.

In order to verify and evaluate the C4ISR systems before they are built, this paper proposes an approach to make the architecture developed by DoDAF executable. The model transformation technologies in model driven architecture are used to transform the architecture products, such as composite structure diagram, state machine diagram, activity diagram and sequence diagram, to single Simulink models and comprehensive Simulink models. The proposed approach can also effectively reuse the existing simulation blocks in the Simulink library to strengthen the ability of the generated Simulink model from architecture. Through the execution of the generated Simulink models, the data from the simulation can be used for the verificaiton and evaluation of the CRISR architecture. The case study shows the feasibility of the proposed approach.

An agent based model (ABM) has been designed, developed, and implemented for the obesity epidemic. The Obesity ABM has been shown to serve as a decision support system as well as for running in-silico experiments. Eight in-silico experiment were run with different experimental parameter setups. The results suggest that food prices is an effective strategy to reduce obesity compared to exercise, individual encounter, number of food source allocations, and advertisements.

Agent based modeling and simulation is widely recognized as an effective tool for the analysis of complex systems. This paper proposes a novel approach to modeling and high-performance parallel simulation of scalable agent models based on actors and the

Theatre

agency. The approach aims to an exploitation of the computing power of modern clusters of multi-core machines. Key factors of the approach are (i) it allows to take advantage of the lock-free cooperative model of concurrency of actors even in a parallel/multi-threaded scenario, (ii) it avoids serialization of messages exchanged among actors residing on different theatres allocated on a same CPU. Achievable execution performance of the proposed simulation framework is demonstrated through the parallel/distributed simulation of a large-scale multi-agent system.

Creating complex and realistic crowd behaviors can be a difficult and time consuming task. By drawing the successful experiences of behavior-based AI and multi-agent simulation framework, this paper presents a behavior-based crowd simulation framework for riot controlling in city environment. A well-designed behavior-based prototype system is developed, which takes the advantages of the dynamics of interaction among the basis behaviors repertoires. The basis behaviors repertoires implemented by decision rules are composed of three parts, which correspond to the behaviors of the civilians, riots and soldiers respectively. Then these basis behaviors are combined into more complex behaviors by behavior selection mechanism. Eventually realistic crowd phenomena are created in the scenarios of riot controlling in city environment. We argue that this approach gives better results than conventional methods.

Based on the analysis of characteristics of simulation capability scheduling problem in cloud simulation platform, this paper gives its mathematical description and introduces a modified shuffled frog leaping algorithm (MSFL) to solve the above optimization problem with multi-mode constraint. The MFSL introduces GA to code the feasible solution space. During the random execution of coding, decoding and mutation, it increases three layers of coding constraints including simulation capability, task logic and feasible mode, to ensure the randomness of the solving process in the controllable scope. Thus it can reduce the search range of solution space, get rid of the meaningless illegal solution, and ultimately improve the convergence speed of the algorithm and avoid precocity.

For multi-aisle automated warehouse scheduling optimization problem, a mathematical model with constraints is established, and a new shuffled frog leaping algorithm is proposed. During the process of obtaining optimal solution, to enhance the local search ability, stepsize is adjusted adaptively, and the frog individuals are guided to update. Meanwhile, in order to maintain the diversity of the populations and strengthen the global search ability, heuristic mutation operation is embedded. This not only ensures the global optimization, but also enhances the convergence efficiency. To verify the performance of the proposed algorithm, it is compared with shuffled frog leaping algorithm (SFLA) and genetic algorithm (GA) through simulation combined the industrial real case. Results show that the proposed algorithm achieves good performance in terms of the solution quality and the convergence efficiency.

In this paper, we consider the problem of rescheduling human resources in a battalion where new activities are assigned to the battalion by higher headquarters, requiring modification of an existing original schedule. The problem is modeled as a multi-criteria optimization problem with three objectives: (i) maximizing the number of tasks that are performed, (ii) minimizing the number of high-priority tasks that are missed, and (iii) minimizing the differences between the original schedule and the modified one. In order to solve the optimization model, we adopt Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The accuracy of NSGA-II in this context is verified by considering a small-sized problem where it is easy to verify solutions. Furthermore, we consider a realistic problem instance for a battalion with 400 agents and 66 tasks in the initial schedule. We present the computational results of rescheduling when unpredictable activities emerge.

Missile seeker’s stabilization platform, also called coordinator was one of the key parts of seeker. In this study, an ADAMS/Matlab co-simulation environment for the design of seeker’s stabilization platform was proposed. First, the mechanical model of coordinator is analyzed, virtual prototype model of the coordinator was built through SolidWorks and ADAMS, and the control model of the coordinator was built through MATLAB and Simulink toolbox. Then co-simulation model was achieved through ADAMS/Control block and Matlab/Simulink port. At last, model accuracy was verified by using coordinator’s real data. With all of these, control system of the coordinator was designed in the co-simulation environment, and isolation performance of the coordinator was tested in this co-simulations environment. Simulation results show that the coordinator’s design work based on the ADAMS/Matlab co-simulation environment is feasible, effective and practical, and it has advantages such as higher fidelity of controlled objective, easier for modeling and debugging compared with traditional design strategy of mathematical methods, and provided a new design approach for high performance coordinator.

Patient-to-image registration is a fundamental step of Image Guided Neurosurgery System. In this paper, we propose an automatic technique to register the patient space with the preoperative images based on fiducial markers. Our technique includes three parts. First, we identify the markers in the image space based on multi-scale features and then cluster all this features to find marker centers. And in patient space, we combine Trajkovic’s and Harris’s algorithm to detect the corners in the center of the markers and then reconstruct 3D coordinates based on binocular stereo vision. At last, we register these two sets of centers using RANSAC. Experiments show that the marker centers can be localized precisely and the two space can be perfectly registered.

The creditability of simulation model is validated by the classical method of Theil’s inequality coefficient though analyzing the consistency between the simulation output and reference output. The reference output is not treated as the benchmark for comparison in the classical method and the difference of trend between the simulation output and reference output is not considered. For solving the problems, the algorithm of Theil’s inequality coefficient was improved, the models for describing the coincident degrees of position and trend between the simulation output and reference output were given and the simulation model validation method based on principal component analysis was proposed. The rationality and efficiency of the method were validated in the application.

Data compression is always needed in large-scale time-varying volume visualization. In some recent application cases, the compression method is also required to provide a low-cost decompression process. In the present paper, we propose a compression scheme for large-scale time-varying volume data using the spatio-temporal features. With this compression scheme, we are able to provide a proper compression ratio to satisfy many system environments (even a low-spec environment) by setting proper compression parameters. After the compression, we can also provide a low-cost and fast decompression process for the compressed data. Furthermore, we implement a specialized particle-based volume rendering (PBVR) [2] to achieve an accelerated rendering process for the decompressed data. As a result, we confirm the effectiveness of our compression scheme by applying it to the large-scale time-varying turbulent combustion data.

In order to let administrators know their QOS of wireless LAN both in convenience and safety of service range, an interactive and immersive visualization of high frequency electromagnetic wave propagation on the CAVE has been studied with authors, which represents the propagation as the volume data defined by the beam tracing technique with sets of three rays. In the previous study, we used distributed computing on the tracing and successive algorithm to generate the volume data. Through this way, the authors reduced the waiting time largely. However, the accuracy of generated beam need to be improved. Especially the method of division of beam which is from one zone enter the another zone must be improved. In the previous system, we just stack the intensity of electromagnetic wave which enter into the new zone, but have not considered about the direction of the ray. Therefore in this paper, we aim at making the method of division to get better.

In medical, scientific and other fields, transparent surface visualization is useful to investigate inner 3D structures. Such visualization usually uses the polygon graphics, where the polygons must be sorted along the line of sight. The sorting, however, requires long computation time for large-scale data. Besides order of polygons in the sorting often becomes indefinite especially for intersecting surfaces. On the other hand, the particle-based volume rendering was proposed as a transparent-rendering method which does not require sorting. In addition, the important feature of this method is to generate the particles first only once. The purpose of this paper is to execute the surface rendering with the opacity by using the volume texture. Furthermore, we show the 3D fused image, such as volume-surface.

Hardware-in-the-loop simulation is necessary for the development of missile’s flight control system. The influence of the simulation equipment errors to simulation results cannot be ignored. This paper introduces both the composition of hardware-in-the-loop simulation system and the clock synchronization strategy in particular for a certain missile. Major errors, which mostly affect the precision of simulation, are studied. Through theoretical derivation and experimental verification, the error models of communication time delay, three-axis rotary table, load simulator and data acquisition are established. Finally, based on mathematical simulation the influence of errors on simulation results is confirmed, and the validity of the error models is verified by contrast with hardware-in-the-loop simulation test results. The experimental results show that each error model can meet the demand of the simulation accuracy analysis. It can provide the theory basis for analysis, measurement and error compensation for hardware-in-the-loop simulation system.

Critical infrastructure networks include the highly complex and interconnected systems that are so vital to a city or state that any sudden disruption can result in debilitating impacts on human life, the economy and the society as a whole. Some of the interdependencies among infrastructure components are perhaps unforeseen and methods for vulnerability analysis of infrastructure networks should therefore incorporate the possibility of potential unforeseen interdependencies in such networks. This paper proposes using an optimization approach to iteratively search for potential unforeseen interdependencies and failures that can maximize connectivity loss in infrastructure networks due to cascading failures. In order to illustrate the proposed approach, an agent based model of an infrastructure network and its known interdependencies has been presented, with a genetic algorithm applied to search for potential unforeseen interdependencies as well as node failures that can result in the maximum loss of infrastructure network connectivity.

Multi-resolution modeling (MRM) is widely used in manufacture industry, environment science (climate, geometry, map), science (material, biology) and so on. Dozens of theories and methods are proposed to MRM. However, most of these MRMs are not designed for simulation, which leads to MRM failures in terms of information loss, consistency maintenance and resolution changes. To solve these failures, this paper introduces

C

onnector-

o

riented

Re

solution

S

tate Chart-based

S

ystem (CORES): a novel MRM approach with emphasis on choosing appropriate resolutions for simulation. In CORES, Resolution State chart, a UML state chart, is modeled to specify the resolution changes. And Connector, the connection of different resolutions, is proposed as a standby part to fulfill the four requirements on relationships between models of different resolutions. Finally, a dimension-variable linear system is modeled to demonstrate CORES approach, and the numerical results verify our approach.

Detailed simulation models have to incorporate random effects. Since the generation of randomness is subject to several shortcomings, this needs to be considered for the setup and evaluation of simulations. On the basis of well-known metrics for the domain of V2X communication we will evaluate the influences of differently generated random sequences on the simulation. We will show that it is important to pay attention to avoid skewed results caused by random number generation and ensure the statistical relevance of the simulation series. It can be stated that well established random number generators are suitable. Meaningful simulation results rely rather on a sufficient number of simulation runs which in turn will depend on the applied models.

Threshold bootstrap is a modified bootstrap method that resamples data from the autocorrelated simulation outputs. The threshold bootstrap calculate the ensemble average of sample as an estimator for population mean as do other bootstrap methods. Sometimes, however, an estimator of simulation output is generated by the concept of time average such as mean queue size in queueing system. In this situation, to analyze the simulation output more efficiently, we introduce a method of generating the confidence intervals for time averaged estimators using the threshold bootstrap. Numerical examples are provided to verify the confidence interval produced by our method.

This paper adopted the system configuration to assess the reliability of a target system instead of making a fault tree (FT), which is a traditional method to analyze reliability of a certain system; this is the reliability block diagram (RBD) method. The RBD method is a graphical presentation of a system diagram connecting the subsystems of components according to their functions or reliability relationships. The equipment model for the reliability simulation is modeled based on the discrete event system specification (DEVS) formalism.

In this paper, the composite nonlinear feedback (CNF) technique is applied for yaw tracking control of active front steering system with the objectives to improve the transient performance of yaw rate response. For lateral and yaw dynamics analysis, nonlinear and linear vehicle models are utilized as actual vehicle plant and for controller design respectively. The designed controller is evaluated using J-turn cornering manoeuvre condition in computer simulation. The simulation results demonstrate that the application of CNF for yaw rate tracking control improves the yaw stability and vehicle handling performances.

A new method of epistemic uncertainty reduction is investigated according to the uncertainty of modeling and simulation. First, technical background of the uncertainty propagation in modeling and simulation is introduced. Uncertainty propagation procedure is divided into three major steps. Next, an epistemic uncertainty reduction method based on two-stage nested sampling uncertainty propagation is proposed, Monte Carlo Simulation method for the inner loop is applied to propagate the aleatory uncertainties and method based on optimization method is applied for the outer loop to propagate the epistemic uncertainties. The optimization objective function is the difference between the result of inner loop and the experiment data. Finally, the thermal challenge problem is given to validate the reasonableness and effectiveness of the proposed method.

This paper presents two intelligent identification approaches for rotor resistance of an indirect vector controlled induction motor drive. First approach is based on fuzzy logic control (FLC) able to compensate for variations and errors, FLC scheme was employed to overcome the lack of a precise mathematical model of the process. In the second approach is based on artificial neural networks (ANNs), the error between the rotor flux linkages based on a neural network model and a voltage model is back propagated to adjust the weights of the neural network model for the rotor resistance estimation. The performances of the two intelligent approaches are investigated and compared in simulation.

Taking velocitydirectional measure and dynamic directional measure as the jumping performance evaluation indexes, the improvement of jumping performance of the jumping robot is pursued in the point view of mechanism design. On the basis of the jumping robot mechanism model, the kinematic and dynamic equations in take-off phase are established, and the velocity mapping relationship from the joint space to the centroid movement space and the acceleration mapping relationship from the joint driving torque space to the centroid acceleration space are obtained. In order to improve the robot’s jumping performance, velocitydirectional measure and dynamic directional measure combining with the optimal algorithm are used to optimize the mechanism parameters of the jumping robot. Through the calculation of example, the optimal results show that the study on the mechanism parameters optimal design of the jumping robot is feasible by introducing the theory of velocity directional measure and dynamic directional measure.

Widely used in the static/dynamic stiffness test of aircraft actuation systems, Motor-driven load simulator (MDLS) simulates the aerodynamic load and exerts the load on actuation system. MDLS endures position coupling disturbance from active motion of actuation system, and this inherent disturbance is called extra torque. However, to eliminate the influence of extra torque is the key issue regarding to the MDLS controller design, as the extra torque may degrade the performance of MDLS seriously. A compound torque control algorithm based on tracking differentiator (TD) is proposed for MDLS in this paper. This algorithm reflects the essential characteristics of MDLS and guarantees transient tracking performance as well as final tracking accuracy. In detail, firstly, the mathematical models of MDLS are derived, and the influence of the extra torque is also studied. Tracking differential filter is then utilized to identify the actuator’s velocity, acceleration and jerk, which can compensate the extra torque. Finally, based on the structural invariability theory, a compound controller is developed, which consists of forward path corrector, feed-forward controller and differential tracking filter. Simulation and experiment comparative results are obtained to verify the high-performance nature of the proposed control strategy; the tracking accuracy and bandwidth are greatly improved.

Noise generation during decompressing hydrogen in fuel cell vehicles is an issue requiring technological solution. This paper studies noise reducing effect and the flow characteristic of radial slits installed in a pressure reducing valve. Simulation is carried out to estimate the pressure–flow characteristic of the radial slit as a noise reducing mean. The simulation indicates a decrease of Reynolds number in the downstream-side of the radial slits structure, which causes noise reduction. Moreover, we proposed installing radial slits to the downstream of a conventional valve. Noise reduction by this new design was verified with a series of experiments. As a result, the valve with radial slits has a noise reduction effect of about 12.1 dB (A) compared with the conventional valve.

Assembly quality control is a vital problem in large gas turbine manufacturing. Assembly quality may not meet the requirements though each manufactured part’s precision is within its range. The paper discusses the assembly quality analysis and control in large gas turbine manufacturing. An intelligent assembly quality control solution using symbiotic simulation is proposed, which combines ON-line Simulation Module (ONSM) with OFF-line Simulation Module (OFFSM). Its mechanisms and partial techniques are discussed. In the end, a measurement simulation of a corporation’s gas turbine using

Virtual Assembly Supported System

(VASS) is realized, which verifies the mechanisms of the solution.

Partitioning is a crucial factor in VLSI distributed simulation. This paper focuses on the partitioning problem for asynchronous handshake circuits generated by the Balsa asynchronous hardware synthesis environment. A quantitative analysis is presented for multilevel partitioning, as exemplified by the

metis

library.

In this paper, we propose new product-type iterative methods by introducing the BiCGSafe strategy, i.e., utilization of associate residual in place of residual, to the variants of GPBiCG. We refer to BiCGStar (BiCG with stabilization of associate residual) and its improved version of BiCGStar method. BiCGStar and BiCGStar-plus methods outperform compared with the conventional iterative methods. Moreover, our proposed methods are suited to parallel computer with distributed memory systems, since they require single global synchronization per one iteration.

To meet the requirement of interaction and real time modeling in simulation scenarios, a strategy for scenarios construction is proposed. We take advantage of the technique of augmented reality to study. In order to constitute the scene we reconstruct fluid surface from video combining the fluid motion vectors with LBM (Lattice Boltzmann Method) and refine the height field by interpolating distribution of the fluid particle. Based on the purpose of virtual and real object combination, this study proposes a method of tracing the gold feature points between frames using continuity of particle movement. The strategy of dichotomy is taken to refine the camera intrinsic parameters and SBA (Sparse Bundle Adjustment) method is taken to optimize the intrinsic and extrinsic parameters. Further experiment results demonstrate that it is a valid and efficient method for simulation environment constructing.

In this paper, we present a novel mediate-based framework for ABS (Agent-based simulation) which integrates common functions for commanders and operational entities in military analytic simulation. This framework aims to provide architecture for agents that run faster than real-time. Traditional “sense-think-action” cycle for multi-agent is extended to “sense-think-lookahead-action” cycle to reduce computation complexity and avoid possible loss of interactions. And a simulation platform with three mediators is designed for typical actions of military agents. The initial implementation of sense mediator is described and the spending of time for a simple scenario is compared with traditional approaches.

Simulation is an important approach to the study of scenarios of confrontation among antagonistic groups. It remains a research issue to explore the influence of the crowd size and imbalance between groups’ sizes on the process of confrontation. In this study, a multi-agent simulation system has been developed with functional programming model (FPM). FPM can easily formulate the simultaneous behaviors/actions of individuals. It also provides “communication backbone” for agents’ interactions. A timing system has been designed to drive the simulation procedure. Our simulations focus on whether/how a confrontational scenario may remain stable. Experimental results indicate that with the increment of the overall size of the crowd in confrontation, the possibility of the scenario getting out of control rises. A relatively small scale of crowd is much more controllable.

Pitched at problems needing to be solved for evaluating the digitized force’s command & control (DF C2) system, this paper proposes the major contents and processes for evaluating the C2 system’s effectiveness based on simulation experimentation, lays down the Measures of Efficiencies(MoEs) system of effectiveness evaluation (EE) for the C2 system, and analyzes, through the design of experiment samples and the planning of the evaluation process, how to use the simulation-experiment approaches of comparison and statistics to conduct effectiveness evaluation, contribution analysis and optimization analysis of the C2 system.

Rapid innovations of ICT enable ubiquitous, mobile and smart computer applications almost anywhere at any time. Permanently growing pervasiveness of these systems and applications at reasonable costs leads to significant changes of learning and training platforms and environments. While virtual simulation and virtual reality have played a dominant role as training platforms over past years, serious games are now receiving more and more attention due to added visualization, AI capabilities, and their availability on smart mobile devices.

As design and development of a smart game is extremely complex and expensive, its sale depends on its attraction for a broad gamer community (ranging from “digital nerds” to novice users) and on multiple usability. Therefore, the cost-effective development of a game-based learning and training platform for very specific domains like in our case for military, medical or first aid applications with limited number of potential users require the design of flexible, cost-effective game architectures for multiple use. This paper proposes such a flexible serious game architecture as first aid and medical emergency training platform for military personal. It reports on a research project sponsored by the German Federal Armed Forces (Bundeswehr).

With recent development of personal computer, interactive learning tools for educational purposes have evolved, from the use of blackboard and physical objects to the recent use of graphical animations on Personal Computers and Tablet PCs. The use of technology not only increases the effectiveness of personal computer as an educational tool, it also helps in engaging a learner. In this paper we attempt to create a computerized version of the popular beer program albeit with the use of 3D animation using an off-shelf simulation tool namely Flexsim

TM

Simulation System. The approach has expanded the usage of an industrial simulation tool from just a simulation and modelling tool to be used as a platform for interactive game development for educational purpose. With the built-in feature in 3D graphic animation it also shorten the time required to develop the game model.

We present an efficient framework for fluid-solid coupling, including both rigid and elastic bodies. Based on a unified particle model, we apply different coupling scheme for fluid-solid and solid-solid coupling respectively. Realistic and versatility are achieved by coupling all the objects adaptively. With the help of GPU accelerating, we gain a real-time simulation.

Outlier in simulation can help people to know the defect of simulation system. With the rapid expansion of data scale, conventional outlier detection methods begin to have trouble dealing with large datasets. In this paper, we propose an Entropy based Fast Detection (EFD) algorithm which incorporates the new ideas in handling big data. The algorithm takes the information entropy measure as the core, with attribute frequency value as the auxiliary. By means of rapid computation of decreased entropy, the outliers can be got quickly. The results show that EFD algorithm can detect the outliers in high efficiency without obvious loss of accuracy.

In this paper, we built simulation model of the production line from one car engine parts plant in Beijing, in order to find proper solutions to raise productivity. The method of Discrete Event Simulation was used to construct the simulation model on account of the fact that production line was a typical discrete event system. Besides, worker heterogeneity, stochastic environment and the effect of worker learning and forgetting were introduced into simulation model to make it closer to reality. We proposed different schedule policies to manage the running of production line with the verification from simulation experiments. Then, by taking advantage of the simulation results obtained previous, we built the optimization model by applying Markov Decision Process (MDP) to seek for the best policy promoting the productivity of production line.

The simulation practice in discrete event logistics system (DELS) domain lacks objective and operable methods in fidelity evaluation and management which leads to high costs or inadequate effectiveness of simulations. This paper provides an approach to evaluate the fidelity of simulation models for DELS. Simulation Fidelity is composed of experiment fidelity and model fidelity. Model fidelity is described by the ratio between the simulation model and the understood reality model. Next, fidelity is divided into four dimensions: structural, correlational, temporal and sensorial. Then a three-step operable approach to evaluate fidelity using Fidelity Evaluation Scale is presented by decomposing and analyzing the model in Fidelity Template, enumerating and calculating the indicators of the dimensions. An example is given showing how the approach is used in simulation practice in logistics context. This approach provides an operable and quantitative evaluation of fidelity which will benefit the trade-off between the costs and effectiveness of simulations of DELS.

Since its introduction in the Workshop on Grand Challenges for Modeling and Simulation in Dagstuhl 2002, Symbiotic Simulation has proven its versatility in many diverse areas ranging from manufacturing to pedestrian evacuation. This paper presents a new application of Symbiotic Simulation in the simulation and generation of traffic incident management strategies. The framework for the generation and evaluation of incident management strategies is used in which Symbiotic Simulation is the core technique of the Strategy Generation Module. Preliminary experimental result shows the effectiveness of Symbiotic Simulation in helping to simulate and select the best strategy to improve the traffic condition. Challenges are also highlighted with potential research direction.

In complex product design enterprise, different departments establish private simulation centers (including computing clusters, application software, job scheduling system etc.), and the resource utilization of each simulation cluster is uneven. So the whole enterprise simulation resources cannot be fully effective used,resulting in low efficiency of simulation and long time waiting. This paper proposed a method of simulation job cooperative scheduling on the clusters with heterogeneous systems, in order to reduce the waiting time after submitting jobs, so it can achieve efficient use of simulation resources in whole enterprise. The instance of one actual simulation problem in this paper shown the job execution time is reduced, and the scheduling method is highly efficient and reliable.

In order to solve the problem that the heterogeneous knowledge in aircraft design is difficult to share, reuse and support to reason each other, a ontology model of knowledge, based on the unified description framework, was proposed. Firstly, the formats of representation for all kinds of knowledge in aircraft design knowledge were studied, and then a unified description framework for this knowledge was proposed. Secondly, the ontology model of knowledge was studied. In this model, basic cell for modeling was defined, which could be used to modeling directly. At last, an example, modeling of pneumatic knowledge in aircraft design verified the validity of the modeling method in this paper.

The visualization system of pollutant distribution contributes to scientific decision-making in the emergency pollution affairs. In this paper, we propose a framework which supports 3D visualization for real-time distribution and situation forecast of atmospheric chemical pollution. The core of our framework is a distributed system infrastructure, which is designed for massive data storage and parallel computing. The stored data includes terrain elevation, vector maps, satellite maps, meteorological data and concentration data from gas sensors. High-performance computing generates gridded data for visualization. Web-based 3D visual applications with B/S structure support cross-platform terminal access.

Against the defect detection problem of simulation credibility, a method based on Sobol’ method and orthogonal design is proposed. Firstly, taking acceptable range of simulation credibility as measurement standard, then credible indexes and incredible indexes of simulation system are determined. Secondly, experiment scheme is arranged according to an extended table transformed from orthogonal table, and incredible index’s defect rank is judged by experimental result analysis combining with membership function of defect rank. Thirdly, Latin Hypercube sampling is taken from relevant indexes of incredible index, and then sensitivity coefficients of relevant indexes are calculated using Sobol’ method. Finally an example is given to validate the effectiveness of the proposed method.

For the further study of advanced radar emitter signals (RES) feature, the distribution of advanced RES features was deeply analysis. Normality test method of RES feature distribution was proposed based on the Mahalanobis distance. First, it realized normality test of one-dimensional feature through the calculation of skewness and kurtosis, and then, through the calculation of Mahalanobis distance, it realized the normality test of RES multi-dimensional feature vectors. Simulation results show that, the distribution of RES feature vector doesn’t have the standard normal characteristics. This conclusion can provide the theoretical support for the further analysis of RES features.

In this study, we propose a method of designing IMC-PID based on approximation of polynomial equations. In the industrial field, IMC-PID is used by many engineers, because it has a good robustness and a good performance. However, the design of the conventional IMC-PID controller is complex. To solve this problem, in this paper, we design IMC-PID controller by using polynomial equations approximation. Our simulation results show that the proposed method has a better performance than that of the conventional IMC-PID.

We propose a digital redesign method for plants with input time delay. When a network system is controlled, it is necessary to take into account the time-delay, and to keep the system stable. In this paper, we use the digital redesign and Internal Model Control (IMC). The system is able to compensate input time delay, input side disturbance, and to maintain the stability by combining IMC and input time delay using digital redesign. We confirmed superior performance by simulation study.

Probability density function (PDF) method is implemented in direct numerical simulation (DNS) to simulate turbulent reactive flows (DNS–PDF method). In the DNS–PDF method, a flow field and a non reactive scalar are predicted by the DNS, whereas reactive scalars are predicted by the Lagrangian PDF method, in which a transport equation of joint PDF of reactive scalars is solved by using a large number of notional particles. A mixing time scale for a mixing model used in the PDF method is directly estimated from the DNS result. In the present model for the mixing time scale, the effect of distance between notional particles is implicitly taken into account. The DNS–PDF method is applied to a planar jet with a second-order chemical reaction. The results show that the DNS–PDF method can accurately predict the rms value of mixture fraction fluctuation, and the present model for the mixing time scale is valid. It is also found that the DNS–PDF method can accurately predict mean concentrations of reactive species.

The Phillips spectrum is widely used in the real-time scene simulation of ocean waves. Structural analysis has shown the Phillips spectrum to be an instantaneous spatial spectrum. Its frequency spectrum agrees with the spectrum form raised by Neumann, and is close to the P-M spectrum. Its directional distribution function is in the form recommended by the International Towing Tank Conference. However, the Phillips spectrum has two problems in application. First, neither the value nor the calculation method of the spectral constant

A

is given. Second, the height above ocean surface of the spectral wind speed is not provided. The spectral constant

A

is calculated on the hypothesis that the wave energy per unit area of the Phillips spectrum equals that of the P-M spectrum, and the height is specified with reference to the P-M spectrum. Apart from the Phillips spectrum, other spectrum should be considered, so we use the JONSWAP-Poisson spectrum. The spectrum has the JONSWAP spectrum as its frequency spectrum, and its distribution function is the Poisson form. The two spectra are applied for ocean wave scene simulation. A comparison of the simulation results of the two spectra shows that wind speed and fetch length can affect the shape of the generated ocean wave. The simulated ocean waves of the Phillips spectrum can reflect the wind speed and direction influence on the wave, but they cannot reflect the fetch length effect. The simulated waves of the JONSWAP-Poisson spectrum can embody the effect of the wind speed, wind direction, and fetch length on the wave. The frame rates of the two spectra are equal. To sum up, for wave spectrum selection of wave scene simulation in the maritime simulator, the wind parameter of the spectrum should contain the wind speed, wind direction, and fetch length, and the wave generated by the spectrum should be in (-(,(] of the wind direction. Thus, the JONSWAP-Poisson spectrum is more suitable than the Phillips spectrum. The method has been used in the maritime simulator.

Subthreshold resonance oscillations are observed in many excitatory/inhibitory neurons in our brain. Although they have been thought to play an important role in behavioral or perceptual states in animals, detail properties of these phenomena have not been clarified, yet. It is necessary to understand first these oscillatory features to clarify the contribution of these rhythmic oscillations to higher brain function, such as short-term memory, the working memory, long-term potentiation and long-term depression. Among various voltage-dependent channels thought to be involved in the generation of these oscillations, hyperpolarization-activated potassium channel (h channel) and persistent inactivating sodium channel (NaP) are considered, because these two voltage-dependent channels are closely related to the sustained oscillatory activity observed in Entorhinal cortex and other Neocortex regions. This feature article considers a compartmental neuron model with an h-channel and a NaP-channel. The NaP-channel contribution to the property of subthreshold resonance oscillation is examined by computer simulation of this neuron model.

This paper presents an OM mapping based federation development and execution process for overlapped federation executions. The proposed process includes four main stages: Scenario Analysis, Requirements Analysis, Collaboration Preparation and Federation Execution. It uses mapped OMs to represent collaboration knowledge for overlapped federations in a simple and flexible way. This OM construction and manipulating mechanism improves efficiency and flexibility of overlapped HLA federations and reduces workload without the loss of accuracy and consistency. This paper also discusses some mapping based OM modeling and manipulating issues under the situation of overlapped federation executions, which includes OM mapping template and OM mapping architecture. In the end, the implementation is discussed on the basis of TH_RTI, a RTI version developed by National CIMS ERC, Tsinghua University, China. The proposed approach has great potential to improve efficiency of FEDEP for overlapped federation executions, reduce the work load for dynamic collaborations among overlapped federations, and enhance the applicability and flexibility of HLA systems.

The Base Object Model, BOM, is specially identified as a reusable and composable model component for quick development of simulation models, which is very helpful for multi-resolution system.This paper proposes a framework named BMRSS including the process of components developement, management and simulation. BOMs library and components library are seen as special cases of web services, which further support the models reuse. MDA and XSLT technology are applied for codes auto-generation, and simulation components are generated directly from model documents. The key part of the framework is a 3-level resolution control mechanism: Resolution state chart is used to define the global resolution state, attribute dependency graph captures relationships among attributes between neighboring resolutions, connection BOM defines the entities and interplays related to resolutions. To support the Multi-Resolution component simulation, a dual-engine simulation is designed with an Internal Exchange Service Server (IESS) for each federate and the bottom supporting RTI. An air-to-air attack and defense scenarios which is built including red-side federates and blue-side federates demonstrates the effectiveness of the approach and corresponding tools.

VTF (Virtual Test Framework) is a useful infrastruction for virtual-testing applications. The existed models and applications are mostly built upon HLA specification. In order to make use of these accumulated achievements, it is necessary to interconnect VTF applications and HLA simulation systems using gateway. Since the application interfaces of VTF models is generated according to VFL (VTF Language) file, the gateway should be dynamically re-generated when interconnecting to a new VTF application. The architecture interfaces or time management of exsited gateway is not entirely suitable for VTF. To address these problems, a VTF Gateway generated method is proposed in the paper. After setting mapping relations between VTF data and HLA data by users, VGCT (VTF Gateway Generation and configuration Tool) can generate Runtime Gateway automatically. We also propose a solution for synchronizing the two equivalent heterogeneous systems. Experimental results demonstrate that VTF Gateway is valid and correct.

In recent years, with the development of aviation technology, the airship has many advantages compared to conventional aircraft by the concern in many countries. United States, Germany, Russia, China and many other countries show great interests in the potential applications of the airship. Because the airships volume is very huge, so the landing process will inevitably cause a threat to the security of airline and ground facilities, especially the use of non-forming recovery method of stratospheric airship, the landing of security control is more important. This paper analyzes the forces on airship, modeling the airship non-forming decline model, and establishing a drop in direct sunlight, ground reflection, infrared radiation, convection exchange thermal model. According to the parameters of a test platform, the paper simulates the airship track of non-forming declining. Use the experiment data to analyze the simulation results and verify the validity of the model.

Based on the ideology of cyber physical systems and combining the requirements of aircraft flexible assembly, this paper puts forward ACPS (Assembly-oriented Cyber Physical Systems) and demonstrates its architecture via contrasting between ACPS and traditional assembly system. By taking aircraft components docking as an example, this paper also introduces ACPS’s software and hardware requirements, system composition, functional module division of assembly simulation control system, as well as key issues to resolve. ACPS then will be actualized to improve the level of aircraft assembly as well as provide theoretical and experimental support for next generation smart assembly systems.

Research on factors affecting carrier landing performance of small UAV has vital significance to ensure the safe landing of UAV. The influences of external environmental disturbance and UAV lateral attributes change are studied. First, Small UAV lateral carrier landing system is constructed. Comprehensive computer models, which include ship dynamics, airwake, navigational error, and airplane dynamics and kinematics, dynamic airplane control structure based on improved LQR with frontal compensator, are then designed to simulate unmanned carrier landings. Second, aircraft lateral attributes are varied and landing performance statistics are recorded for each configuration. Finally, the aircraft preliminary design limits are generated. Simulation results show that severe sea condition has the greatest impact on landing dispersion, and in lateral aerodynamic attributes, side force coefficient with sideslip angle which is generally negative is the most important factor. Increasing its absolute value with physical constraints will significantly improve landing performance.

Field mill instruments are widely employed for the measurement of atmospheric electric fields, dc voltages, and electric fields around electric transmission line. The key point of an electric field sensor is calibration. There is some shortcoming in traditional manual calibration. A set of automatic calibration system is simulated and designed herein based on the virtual instrument technology and applied to improve the calibration efficiency and accuracy of the field mill.

To investigate applicability of the eXtended Element-Free Galerkin method (X-EFG) to realistic problems, the X-EFG has been applied to an electrostatic problem in a dielectric composite material. Numerical experiments show that the electrostatic potential obtained by the X-EFG is naturally distributed in the dielectric composite material, and the accuracy of the numerical solution obtained by the X-EFG is almost the same as that of the Standard EFG (S-EFG). In addition, the condition numbers of the coefficient matrices of the linear systems generated by the X-EFG are considerably less than those of the S-EFG.

Space plasma is a collisionless, multi-scale, and highly nonlinear medium. Computer simulations with the first-principle kinetic equation are essential for studying multi-scale processes in space plasma. We develop a parallel Vlasov (collisionless Boltzmann) simulation code for practical use on currently-existing supercomputer systems. The weak-scaling benchmark test shows that our parallel Vlasov code achieves a high performance and a high scalability. The parallel Vlasov code is applied to various physical problems in space plasma, such as cross-scale coupling between fluid scales and particle kinetic scales.

To use the massively parallel scalar type supercomputer for the large scale numerical magnetospheric simulation, we made performance evaluation of a three-dimensional Magnetohydrodynamic (MHD) simulation code for space plasma simulations of planetary magnetosphere on the K computer with 262,144 cores at RIKEN. For parallelization of the MHD code, we use four different methods, i.e., regular one-dimensional, two-dimensional, three-dimensional domain decomposition methods and a cache-hit type of three-dimensional domain decomposition method. We found that the one-dimensional decomposition and cache-hit type of three-dimensional decomposition achieves the best performance and our MHD code can scale over 200,000 processes on the K computer.

Construction of urban rail transit requires large investment and long cycle, so unified planning and phased construction are generally adopted. Operation of a new line would bring the variation of passenger flow in the transfer station. Urban rail transfer station is a station with two lines or more, which is the important node in the network planning. Whether the current facilities in the station could meet new passenger demand, adaptability pre-assessment needs to be undertaken. This study firstly introduces the definition and content of adaptability assessment in urban rail transit station, and advances two assessment approaches: stationary index analysis and dynamic simulation experiment. Then through the case study, elaborate the specific process and method application. At last, put forward path optimization schemes, ensuring high operational efficiency and service level.

The dynamic behavior of an activated sludge system is highly complex and uncertain. To efficiently control and operate the system, a reliable model capable of accurately describing the several time-varying parallel processes of the system is needed. Most of the existing models are too complex to use for design or control purposes. This paper presents a feed-forward neural network model for the system. The model validation was achieved through the use of appropriate international accepted data of the benchmark simulation model no. 1 (BSM1). Simulation studies revealed that the neural network model exhibited an outstanding performance in predicting the effluent quality, root mean square error (RMSE) of 0.0464, mean absolute deviation (MAD) of 0.0347, correlation coefficient (R) of 0.979 for chemical oxygen demand (COD) and RMSE of 0.1103, MAD of 0.0794, R of 0.841 for the total nitrogen (TN) could be acheived. The model is quite effective and suitable tool for the activated sludge system.