Study of hierarchical federation architecture using multi-resolution modeling

This paper aims at finding a solution to the problem aroused in complex system simulation, where a specific functional federation is coupled with other simulation systems. In other words, the communication information within the system may be received by other federates that participated in this united simulation. For the purpose of ensuring simulation system unitary character, a hierarchical federation architecture (HFA) is taken. Also considering the real situation, where federates in a complicated simulation system can be made simpler to an extent, a multi-resolution modeling (MRM) method is imported to implement the design of hierarchical federation. By utilizing the multiple resolution entity ( MRE ) modeling approach, MRE for federates are designed out. When different level training simulation is required, the appropriate MRE at corresponding layers can be called. The design method realizes the reuse feature of the simulation system and reduces simulation complexity and improves the validity of system Simulation Cost (SC). Taking submarine voyage training simulator (SVTS) for instance, a HFA for submarine is constructed in‘this paper, which approves the feasibility of studied approach.     

面向自动驾驶的仿真场景自动生成方法综述

随着自动驾驶测试验证对虚拟仿真场景依赖程度的增加,传统基于专家经验的场景枚举生成方法已无法满足测试需求.数字虚拟仿真场景自动生成方法在场景多样性、危险性、可解释性、生成效率等方面存在巨大技术优势,是提高汽车自动驾驶技术测试验证安全性和可靠性的关键,已成为当前汽车智能化领域的研究热点.在广泛调研场景自动生成方法领域研究成...     

基于BIM技术的岩土工程三维地质模型创建方法研究

为了解决岩土工程中的三维地质信息模型可直接应用于指导设计、施工过程的问题,通过对常用BIM软件在三维地质信息模型创建方法、适用性的对比分析,总结出岩土工程三维地质信息模型创建的高效方法,并通过工程实际应用证明该方法高效、便捷、直观、模型信息齐全、可操作性强,基本满足设计及施工的需求。     

基于CATIA软件的楔形盾构隧道管片参数化建模与排版

为提高楔形盾构隧道管片拼装拟合设计效率,基于达索CATIA V6软件平台,分析管片几何结构模型建模与隧道设计曲线拟合原理。通过盾构管片参数换算,建立楔形盾构隧道管片环参数化建模标准库,设计函数运算关系并编辑脚本,然后以局部坐标系转换的方式实现隧道曲线参数化拟合,编写排版拟合程序,并应用排版程序分析不同楔形量对通用楔形盾构管片隧道曲线拟合精度的影响。最后,依托杭州市艮山快速路下沙段提升改造工程,对工程初设中直径为14 m的盾构管片进行建模排版模拟,结果表明排版程序计算结果满足工程需求,能为实际工程提供一定依据。     

船舶电子装备研制质量风险建模与评价方法

船舶电子装备的发展水平是船舶工业竞争力的重要衡量标准,由于船舶电子装备研制过程繁琐、探索性极强且成本高,导致研制过程中的风险防控难度非常高,为减少损失,对船舶电子装备项目研制中的质量风险进行建模与评价是必不可少的。本文针对这些问题,首先对船舶电子装备项目研制过程中的风险进行了研究,其次给出了船舶电子装备研制项目质量风险建模方法,然后根据风险控制目标要素的特点抽取决策变量建模,并根据模型选择合适的风险评价方法进行评价。最后以某所的综合船桥系统的研制为例,对上述所提出的方法进行验证,结果表明,在该系统研制过程中该方法风险识别的覆盖率为100%,风险评价的拟合度均超过80%。     

BIM技术在重力式方块码头工程设计施工中的应用

针对北方某重力式方块码头工程设计及施工过程中存在的构件碰撞、工程量计算精度低、技术交底效率低等问题,进行BIM技术在重力式方块码头工程设计施工中的应用研究.通过创建三维信息模型进行碰撞检查、工程算量、进度模拟以及可视化工艺技术交底,有效解决了以上问题,得出如下结论:BIM技术可视化降低了沟通成本,为工程精细化管理提供了技术手段;利用BIM技术在设计阶段解决碰撞问题,降低施工时的返工风险;基于BIM模型的工程算量更加直观,具有完整、快捷、精确等特点;利用BIM技术对施工进度计划进行可视化预演,可辅助施工技术人员对施工方案进行优化.     

Methods for forecasting the market penetration of electric drivetrains in the passenger car market

Current car technologies will not solve upcoming challenges of mitigating greenhouse gas emissions in road transport. Projections of the market penetration by alternative drive train technologies are controversial regarding both forecast market shares and applied scientific methods. Accepting this latter challenge, we provide a (so far missing) overview of methods applied in this field and give some recommendations for further work. Our focus is to classify the applied methods into a convenient pattern and to analyse models from the recent scientific literature which consider the electrification of light-duty vehicles. We differentiate the following bottom-up approaches: Econometric models with disaggregated data (such as discrete choice), and agent-based simulation models. The group of top-down models are subdivided into econometric models with aggregated data (e.g. vehicle stock data), system dynamics, as well as integrated assessment models with general equilibrium models. It becomes obvious that some methods have a stronger methodological background whereas others require comprehensive data sets or can be combined more flexibly with other methods. Even though there is no dominant method, we can identify a trend in the literature towards data-driven hybrid approaches, which considers micro and macro aspects influencing the market penetration of electric vehicles.     

Investigating scalability in population synthesis: a comparative approach

In this paper, we investigate the influence of scalability on the accuracy of different synthetic populations using both fitting and generation-based approaches. Most activity-based models need a base-year synthetic population of agents with various attributes. However, when several attributes need to be synthesized, the accuracy of the synthetic population may decrease due to the mixed effects of scalability and dimensionality. We analyze two population synthesis methods for different levels of scalability, i.e. two to five attributes and different sample sizes – 10%, 25% and 50%. Results reveal that the simulation-based approach is more stable than Iterative Proportional Fitting (IPF) when the number of attributes increases. However, IPF is less sensitive to changes in sample size when compared to the simulation-based approach. We also demonstrate the importance of choosing the appropriate metric to validate the synthetic populations as the trends in terms of RMSE/MAE are different from those of SRMSE.     

离岸深水码头波浪力作用下顶高程对码头损伤的影响

针对剪胀性海洋地基,建立了地基-桩-上部结构和波浪动荷载作用的三维动力响应数值模型。将损伤本构模型应用于码头结构,分析了不同码头顶高程下码头结构和地基的动力响应规律。研究结果显示:高桩码头受到波浪冲击,相对净空ΔhH为0. 33左右时内力最大,损伤最严重;相对净空为0. 5时损伤和内力明显减小;相对净空大于0. 42时桩基内最大等效应力随顶高程增加明显减小。虽然桩基周围土层的影响范围变化不是很大,但上部结构具有较大的动力放大效应,即使是小量的地基变形量变化也可能引起上部结构内较大的破坏,因此设计时应考虑地基-桩-上部结构-波浪的相互协同作用效应。针对海洋性地基的非线性变形特性,建议建立整体模型进行分析,使设计更加科学可靠。     

BIM建模技术在海事码头结构设计中的应用

针对目前我国海事码头结构设计模块化程度较低的问题,基于两项在建海事码头工程,采用BIM建模技术进行结构设计,建立构件和设施模型,赋予设计参数,进行结构配筋,检验构造和功能,输出设计图纸和施工组织方案,获得模块化的设计成果,实现"实体工程"和"数字工程"的双移交。结果表明:BIM建模技术能以模块化的设计方法显著提高海事码头工程结构设计的质量和效率,实现成果共享,但建模标准尚未统一,行业内未能形成资源共享。