Development of a parallel semi-implicit two-dimensional plasma fluid modeling code using finite-volume method

In this paper, the development of a two-dimensional plasma fluid modeling code using the cell-centered finite-volume method and its parallel implementation on distributed memory machines is reported. Simulated discharge currents agree very well with the measured data in a planar dielectric barrier discharge (DBD). Parallel performance of simulating helium DBD solved by the different degrees of overlapping of additive Schwarz method (ASM) preconditioned generalized minimal residual method (GMRES) for different modeling equations is investigated for a small and a large test problem, respectively, employing up to 128 processors. For the large test problem, almost linear speedup can be obtained by using up to 128 processors. Finally, a large-scale realistic two-dimensional DBD problem is employed to demonstrate the capability of the developed fluid modeling code for simulating the low-temperature plasma with complex chemical reactions.     

基于Matlab的远距离输电线的数字仿真

Simulink是Matlab中强大的动态仿真工具，它具有构造模型简单、实现系统控制容易、修改参数方便、界面友好、功能强大等优点，成为动态系统建模与仿真应用最广泛的软件包之一。将Simulink用于电力系统的仿真研究近几年逐渐成为人们研究的热点。文中根据双回远距离高压传输线模块的数学模型，并利用Simulink的数学模块，提出了一种基于Mat1ab Simulink软件包的仿真方法，实现对双回传输线正常状态的数字仿真。仿真结果表明，所提出的模型和方法是正确的，实现起来简洁、方便。     

车辆动态称重模型建立与分析

利用ADAMS对便携式轴重仪的动态称重系统建模并验证模型的可靠性.首先根据实际称重传感器结构和建模原理进行建模,控制单一变量仿真称重过程,得到不同速度、重量下的仿真称重数据.然后利用相同参数的便携称重系统实现实际测量,并与相同条件下仿真结果比较分析.实验结果表明,在30 km/h以下,仿真数值与实测数值相差不超过5％,验证了动态称重模型可靠性,为仿真数据取代现场实测提供可行性,为今后称重信号补偿奠定了理论基础.     

MATLAB在电力系统仿真研究中的应用

随着科学技术的发展,电力系统变得越来越复杂,电气工程师掌握一种好的能对电力系统进行仿真的软件是学习和研究的需要。文章简要介绍了MATLAB发展历史、组成和强大的功能,并用两个简单例子分别就编程仿真和框图式仿真两方面分析了MATLAB这种软件在电力系统仿真研究中的具体应用。在充分利用已有模型的基础上,对MATLAB中这两者仿真方式进行有机结合或采取等效电路法,就能对特殊、复杂地电气系统地进行高效仿真研究,因此,掌握编程仿真和框图式仿真是电气工程师学好MATLAB的基础。与众多专门的电力系统仿真软件相比,MATLAB软件具有易学、功能强大和开放性好,是电力系统仿真研究的有力工具。     

DBD lamp converter design using an electrical model of the load

This paper presents a design process of the power supply for a dielectric barrier discharge (DBD) lamp; this design is based on an electrical model of DBD lamps. An identification algorithm is used to find the values of the parameters of the model, on the basis of several experimental waveforms. With the identified model, the design phase of the power supply is simplified and improved, thanks to the simulation of the entire system: the converter along with the lamp. This model also helps to correlate the UV radiation with the current which actually flows into the gas: the latter, being a variable which is not directly measurable, is calculated offline.     

开关磁阻风力发电系统研究

针对传统的基于异步发电机、双馈发电机和永磁同步发电机的风力发电系统稳定性较差,风力发电系统的实验研究需要诸多条件、不易实现的问题,提出了一种在不具备风场实验条件情况下进行基于开关磁阻发电机的风力发电系统研究的方法,即采用直流电动机模拟风力机来进行开关磁阻发电系统的实验。建立了直流电动机模拟风力机的仿真模型,介绍了基于该模型的开关磁阻风力发电系统最大输出功率闭环控制方案。仿真结果表明,该控制方案能使所建立的发电系统快速进行功率调节并进入稳态工作。     

Vega Prime结合OpenGL的导弹尾焰实时模拟

研究基于Vega Prime的导弹作战系统仿真实验,针对使用Vega Prime的粒子特效模拟高速飞行导弹尾焰会出现尾焰不连续而影响仿真可视化效果的问题,提出将Vega Prime与OpenGL相结合的方法.基于粒子系统基本原理,对导弹尾焰进行建模;依据Vega Prime的事件发布订阅机制将OpenGL引入到Vega Prime中.模拟的尾焰形态逼真,动感十足,满足仿真实时性与真实性要求,解决了Vega Prime模拟导弹尾焰存在缺陷的问题.     

A BIM-based simulation framework for fire safety management and investigation of the critical factors affecting human evacuation performance

Fire hazards are a big threat to human life and property safety. The U.S. fire statistics reveal that, in 2017 alone, 1,319,500 fires caused 3400 deaths and 14,670 injuries, which resulted in a loss of $23 billion [1]. Effective evacuation planning in densely occupied buildings should be primarily put in place if both the number of injuries/fatalities and the level of property loss are to be minimized. However, it is not realistic, and is unethical to study human evacuation performance under a burning building. For this reason, computational tools tend to be the best approach for simulating fire growth as well as human response to fire hazards. This study aims to develop a BIM-based simulation framework that implements the Fire Dynamic Simulator (FDS) and agent-based modeling (ABM) for simulating fire growth and evacuation performance for different building layout scenarios. An experimental implementation is conducted to validate the proposed framework, which verified the benefits of (1) using BIM to offer a platform for conducting simulation design and visualizing the simulation results of (a) hazardous fire zones and (b) effective escape routes; (2) simulating fire growth using the FDS tool; (3) developing an agent-based model that accounts for the critical factors affecting evacuation performance; and (4) applying a statistical analysis for investigating the effects of influential parameters from the proposed model. As a result, the simulation outputs can be used to optimize the building design and to investigate the influential factors on human evacuation efficiency. The proposed framework contributes to building fire safety management by enabling to minimize both injuries/fatalities and property loss.     

ANSYS二次开发在PIM充模流动模拟中的应用

论文介绍了ANSYS所具有的针对不同需求、特点和应用范围的多种二次开发技术;根据PIM充模喂料流体的幂律模型,基于ANSYS用户可编程特性中对其FLOTRAN模块流体特性中的粘度模型进行了二次开发,用所开发的幂律模型对I型拉伸试样的PIM充模二维流动进行了数值模拟,模拟结果与实验结果吻合很好;并将二次开发的方法推广到PIM喂料的密度、导热系数、比热等的修改,为将ANSYS强大的计算流体力学功能广泛应用于PIM充模流动模拟的研究奠定了基础。     

卫星电源分系统的联合仿真

卫星电源分系统的仿真涉及多学科领域,依靠传统的单领域、电路级仿真会在元件建模与算法控制之间产生矛盾.为解决元件模型与算法控制的有机统一问题,利用多领域动态系统仿真软件VTB建立卫星电源分系统的模型,并调用Matlab/Simulink中搭建蓄电池充电控制模块,在VTB中实现联合仿真.仿真结果表明:锂离子蓄电池组实现了恒流恒压充电,母线电压始终调节在28V,太阳电池阵和蓄电池组的功率、电流、电压输出都符合在轨卫星的供电要求,基于VTB与Simulink的联合仿真适用于卫星电源分系统的仿真.     

An investigation into the sensory application of DBD plasma actuators for pressure measurement

This paper investigates the effect of air pressure on the current used by dielectric barrier discharge (DBD) plasma actuators and the voltage limits for plasma production in these actuators. The purpose of this research was to determine whether DBD plasma actuators have potential for application as a pressure sensor at sub-atmospheric pressure conditions. It was found that these actuators were sensitive to air pressure and possessed a distinct, non-linear relationship between the electrical current consumed by them and ambient pressure. It was also found that lower and upper voltage limits for plasma production increased approximately linearly with pressure.     

MATLAB在模型参考模糊自适应控制系统仿真中的应用

该文详细介绍了用MATLAB（SIMULINK）语言对模型参考模糊自适应控制（MRFAC）系统进行仿真的步骤和方法，可以看出SIMULINK工具箱是控制系统动态仿真的有力工具，而且相对于以往任何一种仿真方法，MATLAB语言更方便，高效，具有无可比拟的优越性。     

Comparative performance evaluation of latency and link dynamic power consumption modelling algorithms in wormhole switching networks on chip

The simulation of interconnect architectures can be a time-consuming part of the design flow of on-chip multiprocessors. Accurate simulation of state-of-the art network-on-chip interconnects can take several hours for realistic application examples, and this process must be repeated for each design iteration because the interactions between design choices can greatly affect the overall throughput and latency performance of the system. This paper presents a series of network-on-chip transaction-level model (TLM) algorithms that provide a highly abstracted view of the process of data transmission in priority preemptive and non-preemptive networks-on-chip, which permit a major reduction in simulation event count. These simulation models are tested using two realistic application case studies and with synthetic traffic. Results presented demonstrate that these lightweight TLM simulation models can produce latency figures accurate to within mere flits for the majority of flows, and more than 93% accurate link dynamic power consumption modelling, while simulating 2.5 to 3 orders of magnitude faster when compared to a cycle-accurate model of the same interconnect.     

由粗到精的多尺度散焦模糊检测

目的 散焦模糊检测致力于区分图像中的清晰与模糊像素，广泛应用于诸多领域，是计算机视觉中的重要研究方向。待检测图像含复杂场景时，现有的散焦模糊检测方法存在精度不够高、检测结果边界不完整等问题。本文提出一种由粗到精的多尺度散焦模糊检测网络，通过融合不同尺度下图像的多层卷积特征提高散焦模糊的检测精度。方法 将图像缩放至不同尺度，使用卷积神经网络从每个尺度下的图像中提取多层卷积特征，并使用卷积层融合不同尺度图像对应层的特征；使用卷积长短时记忆（convolutional long-short term memory，Conv-LSTM）层自顶向下地整合不同尺度的模糊特征，同时生成对应尺度的模糊检测图，以这种方式将深层的语义信息逐步传递至浅层网络；在此过程中，将深浅层特征联合，利用浅层特征细化深一层的模糊检测结果；使用卷积层将多尺度检测结果融合得到最终结果。本文在网络训练过程中使用了多层监督策略确保每个Conv-LSTM层都能达到最优。结果 在DUT （Dalian University of Technology）和CUHK （The Chinese University of Hong Kong）两个公共的模糊检测数据集上进行训练和测试，对比了包括当前最好的模糊检测算法BTBCRL （bottom-top-bottom network with cascaded defocus blur detection map residual learning），DeFusionNet （defocus blur detection network via recurrently fusing and refining multi-scale deep features）和DHDE （multi-scale deep and hand-crafted features for defocus estimation）等10种算法。实验结果表明：在DUT数据集上，本文模型相比于DeFusionNet模型，MAE （mean absolute error）值降低了38.8%，F_0.3值提高了5.4%；在CUHK数据集上，相比于LBP （local binary pattern）算法，MAE值降低了36.7%，F_0.3值提高了9.7%。通过实验对比，充分验证了本文提出的散焦模糊检测模型的有效性。结论 本文提出的由粗到精的多尺度散焦模糊检测方法，通过融合不同尺度图像的特征，以及使用卷积长短时记忆层自顶向下地整合深层的语义信息和浅层的细节信息，使得模型在不同的图像场景中能得到更加准确的散焦模糊检测结果。     

A fully automated reconfigurable calculation engine dedicated to the real-time simulation of high switching frequency power electronic circuits

Real-time simulation allows rapid deployment and thorough testing of prototyped hardware in the automotive and aerospace industries. However, the simulation of power electronic circuits (PECs) in the context of PC-based simulations is challenging for several reasons, and imposes a limit in the 1–5 kHz range to the achievable switching frequencies. As FPGA devices gain computing power, conducting the real-time simulation of PECs on chip becomes an attractive alternative. This paper demonstrates the feasibility of high-performance floating-point calculation engines aimed for the real-time simulation of PECs on high-end and low-cost FPGAs as well. The paper discusses emerging paradigms for reconfigurable floating-point computing that favor optimal performance and offer near double precision arithmetic at a minimal hardware cost. The effectiveness of the approach is demonstrated by considering three different circuit topologies and simulating their high-frequency stimulation (20 kHz) using the same automated calculation engine. The considered circuits are a boost converter, a two-level three-phase bridge, and a two-level-three-phase bridge driven by a boost converter.     

巡航导弹惯导系统数学仿真

针对常用惯导仿真方法对模拟长时间复杂条件下工作的巡航导弹惯导系统存在一定难度的问题,在分析平台惯导系统数学模型的基础上,通过设计巡航导弹典型飞行航迹,建立惯导器件误差仿真模型,对含有误差的惯导系统进行导航解算,构建了完整的巡航导弹惯导系统仿真模型 .利用MATLAB/Simulink工具对模型进行了仿真与误差统计分析.得到的导航位置误差和速度误差与实际情况基本相符,证明仿真模型建立正确,方法使用得当.为进行惯导及组合导航研究提供了一种实用方法.     

VHDL硬件仿真结果的MATLAB分析法

使用硬件描述语言VHDL以及相应的仿真工具已成为硬件系统设计的流行方法。在一般情况下，通过仿真工具的仿真就可以验证硬件系统的功能是否正确。但是，在有些应用场合，这种方法还不能直观地看出仿真结果的正确性。本文介绍了一种采用MATLAB对VHDL仿真结果进行进一步分析的方法。并结合铁路信号系统中的一个实例介绍了这种分析方法的过程及其应用场合。     

基于MATLAB的模糊电力系统稳定器设计与仿真

该文介绍了如何由模糊逻辑工具箱和Simulink来设计模糊电力系统稳定器，仿真结果表明：该文所设计的模糊电力系统稳定器(FPSS)相比传统的电力系统稳定器(CPSS)能更有效地抑制系统低频振荡，且模糊稳定器的设计与调试过程非常方便、高效。     

基于S-函数的异步电动机变频调速系统的仿真建模

根据电动机的电气状态方程及机械方程，该文给出了利用系统函数(S-函数)创建的异步电动机仿真模型，通过在正弦波脉宽调制(SPWN)变频调速系统的仿真研究，验证了模型的正确性，给出了控制系统的仿真结果。结果表明：这种模型简洁，具有可扩展性和交互式特点，可以作为研究交流调速系统的基础仿真平台。     

A bond graph approach to the modeling and simulation of switch regulated DC-to-DC power supplies

A bond graph approach is proposed for the modeling and simulation of switched DC-to-DC power converters of the boost type, regulated by means of a pulse-width-modulation (PWM) strategy. An average bond graph model of the PWM regulated DC-to-DC power converter is derived using ideal lossless transformer elements. The proposed bond graph model constitutes an “input” to a computer aided package, called DESIS, which automatically generates the system model as a set of differential equations with explicit control parameters. The computer package is also capable of simulating both the average and the actual discontinuous PWM regulated responses of the DC-to-DC power converter for a given feedback duty ratio policy.