Feature-based and objectoriented product information model for welding structure

Product information model for welding structure plays an important role for the integration of welding CAD/CAPP/CAM. However, existing CAD modeling systems are not capable of providing enough information for subsequent manufacturing activities such as CAPP and CAM. A new design approach using feature technique and object oriented programming method is put forward in this paper in order to create the product information model of welding structure. With this approach, the product information model is able to effectively support computer aided welding process planning, fixturing, assembling, path planning of welding robot and other manufacturing activities. The feature classification and representing scheme of welding structure are discussed. A prototype system is developed based on feature and object oriented programming. Its structure and functions are given in detail.

High level architecture evolved modular federation object model

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.

Coach Simplified Structure Modeling and Optimization Study Based on the PBM Method

For the coach industry, rapid modeling and efficient optimization methods are desirable for structure modeling and optimization based on simplified structures, especially for use early in the concept phase and with capabilities of accurately expressing the mechanical properties of structure and with flexible section forms. However, the present dimension-based methods cannot easily meet these requirements. To achieve these goals, the property-based modeling （PBM） beam modeling method is studied based on the PBM theory and in conjunction with the characteristics of coach structure of taking beam as the main component. For a beam component of concrete length, its mechanical characteristics are primarily affected by the section properties. Four section parameters are adopted to describe the mechanical properties of a beam, including the section area, the principal moments of inertia about the two principal axles, and the torsion constant of the section. Based on the equivalent stiffness strategy, expressions for the above section parameters are derived, and the PBM beam element is implemented in HyperMesh software. A case is realized using this method, in which the structure of a passenger coach is simplified. The model precision is validated by comparing the basic performance of the total structure with that of the original structure, including the bending and torsion stiffness and the first-order bending and torsional modal frequencies. Sensitivity analysis is conducted to choose design variables. The optimal Latin hypercube experiment design is adopted to sample the test points, and polynomial response surfaces are used to fit these points. To improve the bending and torsion stiffness and the first-order torsional frequency and taking the allowable maximum stresses of the braking and left turning conditions as constraints, the multi-objective optimization of the structure is conducted using the NSGA-II genetic algorithm on the ISIGHT platform. The result of the Pareto solution set is acquired, and the selection strategy of the final solution is discussed. The case study demonstrates that the mechanical performances of the structure can be well-modeled and simulated by PBM beam. Because of the merits of fewer parameters and convenience of use, this method is suitable to be applied in the concept stage. Another merit is that the optimization results are the requirements for the mechanical performance of the beam section instead of those of the shape and dimensions, bringing flexibility to the succeeding design.

Extended Object Model for Product Configuration Design

This paper presents an extended object model for case-based reasoning （CBR） in product configuration design. In the extended object model, a few methods of knowledge expression are adopted, such as constraints, rules, objects, etc. On the basis of extended object model, case representation model for CBR is applied to product configuration design system. The product configuration knowledge can be represented by the extended object. The model can support all the processes of CBR in product configuration design, such as case representation, indexing, retrieving, and case revising. The presented model is an extension of the traditional object-oriented model by including the relationship class used to express the relation between the cases, constraints class used in the product configuration knowledge representation, index class used in ease retrieving, and solution class used in case revising. Therefore, the product configuration knowledge used in the product configuration design can be represented by using this model. In the end, a metering pump product configuration design system is developed on the basis of the proposed product configuration model to support customized products.

批判性思维在车辆工程专业课程教学中的运用——以汽车电器与电子课程为例

批判性思维是以一种以合理的、反思的、心灵开放的方式进行思考,从而能够清晰准确地表达、逻辑严谨地推理、合理地论证,进而完成思辨精神培养的思维方式。在车辆工程专业新工科人才培养的过程中,培养学生这种思维方式和精神,具有普适性意义,有利于新工科专业教育内涵发展。该文基于批判性思维教学方法的基本理论,结合汽车电器与电子课程教学实践,在教学目标设计、教学内容设计、议题式教学模式和课后辅导等方面,进行批判性思维在车辆工程专业课程教学中运用的探索,以培养具有学习能力的学生,进而满足汽车行业对于复合型人才的需要。

应用无人机可见光影像和面向对象的随机森林模型对城市树种分类

为及时准确的了解城市树种空间分布信息,提升城市居民生活水平和推动城市生态系统可持续发展。以福州市仓山区城市森林为研究对象,应用无人机(UAV)监测城市树种空间分布及其动态变化的可见光影像,根据最佳尺度对影像进行分割,并提取分割对象的光谱、地形、指数、纹理和几何特征。通过对不同类型特征的组合构建不同的分类方案,利用递归特征消除法(RFE)筛选出优选特征子集,利用面向对象方法结合随机森林(RF)模型对城市树种进行分类。结果表明:在随机森林模型分类的过程中,利用光谱特征对树种分类的总体分类精度为82.12%;地形特征对树种分类的贡献度率为14.96%;指数特征和纹理特征的引入,在一定程度提高了树种的分类精度;几何特征的贡献较小,在分类过程中没有明显的贡献。特征优选子集的S10方案分类精度最高,总体精度达92.42%,Kappa系数为0.91。说明特征优选能够降低高维度特征的复杂性,在大幅减少数据冗余的同时提高了分类精度。在最优特征子集下,随机森林(RF)算法分类的总体精度比极致梯度提升(XGBoost)、轻量级梯度提升机(LightGBM)和k最近邻算法(KNN)分别提高了1.15%、1.81%和15.15%,Kappa系数分别提高了1%、2%和17%。

四个数值预报模式对四川强降水过程预报能力评估

为衡量数值模式对强降水过程的预报能力,选取欧洲中期天气预报中心(the European Centre for Medium-Range Weather Forecasts,ECMWF)数值预报产品、国家气象中心区域中尺度数值预报产品(China Meteorological Administration Mesoscale Model,CMA-MESO 3KM)、西南区域中心中尺度模式系统(Southwest Center WRF ADAS Real-time Modeling System,SWC)、国家气象中心全球数值预报系统(China Meteorological Administration for Global Forecast System,CMA-GFS)4个模式预报产品,利用目标对象检验法,对四川2018—2020年共93次强降水过程(≥25 mm·d^(-1))从降水位置、降水面积、降水强度等方面进行检验,在此基础上重点讨论36 h预报时效模式的预报能力。结果表明:(1)随着预报时效越临近,各模式预报平均水平越高,且整体对雨带位置把握较好,更具有参考性。(2)各模式对锋面降水过程预报能力较强,对暖区降水过程预报能力较差。(3)暖区强降水过程可在大尺度模式基础上结合本地中尺度模式进行订正;锋面降水过程则以ECMWF模式预报为基础,参考CMA-MESO 3KM模式对大雨及以上量级降水落区和量级进行调整。

基于IEC 61850的智能水电站建设研究

随着智能水电站的不断发展,水电站产生的海量数据因采用不同的通信标准导致数据孤岛问题加剧。为有效实现数据的共享与整合,研究基于IEC 61850通信标准建设智能水电站。从电站物理对象层级划分、信息对象建模、通信系统建设、一体化管控平台建设等过程阶段,研究基于IEC 61850的智能水电站全过程建设方案框架及流程方法,并从设备对象化建模、标准通信建设、一体化管控平台应用等方面详细阐述了基于IEC 61850的智能水电站全过程建设的关键技术。研究成果可为智能水电站建设打通数据底板基础,对智能水电站的建设及应用具有一定参考价值。

CBL-OSCE教学模式在微生物检验进修生带教中的应用探讨

微生物检验在公共卫生健康事业发展尤其是感染控制领域工作中担负着重要使命,通过加大微生物检验进修生培养力度,提高培养效果来扩充高素质人才是行业发展的必然要求。目前进修生带教缺乏参照标准,考核评价体系尚未建立,探索和研究与学科属性相匹配的进修生教学模式势在必行。在推进继续医学教育创新发展的指导思想下,本文对微生物检验进修生带教现状进行全面分析,探讨案例教学法(case-based learning, CBL)和客观结构化考试(objective structured clinical examination, OSCE)在微生物检验进修生带教和考核中的适用性,阐述将二者联合构建CBL-OSCE教学模式的可行性和实施方案,提出模式优化管理思路,强调模式的灵活应用、教师队伍培训和思政人文融合,保障教学模式顺利推进,为微生物检验人员综合能力提升和学科建设发展提供理论参考。

海洋保护地规划中生态系统模型的应用探究

海洋保护地是海洋生态环境管理的重要措施,科学有效的海洋保护地空间规划能够加强对海洋生物多样性和生态系统健康的保护。探讨面向对象的海洋生态系统评估(Object-oriented simulator of marine ecosystem exploitation,OSMOSE)模型在海洋保护地空间规划中的应用前景,通过深入分析模型原理、关键过程和研究进展,以及结合模型特征及其功能实现,对模型在海洋保护地空间规划中能够发挥的多方面优势进行了重点探究;同时与现有海洋保护地空间规划方法的对比以及与实际海洋保护地案例结合,探讨了OSMOSE模型与现有的海洋保护地空间规划技术方法的异同及有机结合的潜在可能。结果表明,OSMOSE模型在模拟海洋生态系统动态、预测管理策略效果方面展现出的显著优势,模型对多物种相互作用以及时空分布的精准模拟,可以为海洋保护地空间规划提供丰富的数据支撑和决策依据。模型的合理应用不仅为我国海洋保护地建设提供了新视角,还有助于提升海洋保护地的空间规划合理性与管理措施有效性,对促进我国海洋生态保护具有重要作用和应用前景。

SEMANTIC CONSTRAINT MODELER FOR 2D AND 3D GEOMETRY

Design changes for 2D & 3D geometry are the most important features in the process of product design.Constraint modeling for variationl geometry based on geometric reasoning is one of the best approaches for this goal.However,it is difficult for the proposed systems to maintain or handle the consistency and completeness of the constraint model of the design objects.To change this situation,a semantic model and its control approach are presented,aiming at the integration of the data,knowledge and method related to design objects.Aconstraint definition system for in- teractively defining the semantic model and a prototype modeler based on the semantic model are also implemented to examine the idea which is extended to 3D geometric design too.

PBL—雨课堂—OSCE多元化教学模式在临床药学专业本科教学中的应用研究

临床药学专业是一门以合理用药为核心的综合性应用科学,教学结构不仅包含药学专业相关知识,还涉及临床医学的多门课程。如何通过有限的课时将药学理论知识与临床用药问题有机融合,提升本科生的药学综合服务能力是亟待探索的教学问题。本研究将问题驱动教学法(PBL)—雨课堂—客观结构化临床考试(OSCE)相结合,探索出多元化教学模式并应用于临床药学专业教学中,培养学生临床思维的同时提高其药学综合服务能力,是一种值得推广的新型教学模式。

Tracking of Non-Rigid Object in Complex Wavelet Domain

In this paper we have proposed an object tracking method using Dual Tree Complex Wavelet Transform (DTCxWT). The proposed method is capable of tracking the moving object in video sequences. The object is assumed to be deform-able under limit i.e. it may change its shape from one frame to another. The basic idea in the proposed method is to decompose the image into two components: a two dimensional motion and a two dimensional shape change. The motion component is factored out while the shape is explicitly represented by storing a sequence of two dimensional models. Each model corresponds to each image frame. The proposed method performs well when the change in the shape in the consecutive frames is small however the 2-D motion in consecutive frames may be large. The proposed algorithm is capable of handling the partial as well as full occlusion of the object.

离散ADMM方法下像素与对象基元协同优化的遥感影像无监督语义分割

语义分割是遥感影像分析中的重要技术之一。现有方法(如基于深度卷积神经网络的方法等)虽然在语义分割中取得了显著进展,但往往需要大量训练数据。基于图模型的马尔可夫随机场模型(Markov random field model,MRF)提出了一种不依赖训练数据的无监督语义分割思路,可以有效地刻画地物空间关系,并对地物空间分布的统计规律进行建模。但现有的MRF模型方法通常建立在基于像素或对象的单一粒度基元上,难以充分利用影像信息,语义分割效果不佳。针对上述问题,引入交替方向乘子法(alternative direction method of multiplier,ADMM)并将其离散化,提出了一种像素与对象基元协同的MRF模型无监督语义分割方法(MRF-ADMM)。首先构建像素基元和对象基元两个概率图,其中像素基元概率图用于刻画影像的细节信息,保持语义分割的边界;对象基元概率图用于描述较大范围的空间关系,以应对遥感影像地物内部的高异质性,使分割结果中地物内部具有良好的区域完整性。在模型求解过程中,针对像素和对象基元的特点,提出了一种离散化的ADMM方法,并将其用于两种基元类别标记的传递与更新,实现像素基元细节信息和对象基元区域信息的协同优化。高分二号和航拍影像等不同数据库不同类型遥感影像的语义分割实验结果表明,相较于现有的MRF模型,提出的MRF-ADMM方法能有效地协同不同粒度基元的优点,优化语义分割结果。

基于高分辨率遥感影像的面向对象建筑物分级提取方法

数字表面模型(Digital Surface Model,DSM)辅助的基于规则的分类算法对高分辨率卫星遥感影像进行面向对象建筑物提取时存在如下不足:(1)多尺度分割在复杂场景下分割效果差,导致建筑物提取精度较低;(2)影像范围较大时,无法直接通过DSM数据的单一阈值提取建筑物。为克服上述问题,文章提出了一种DSM辅助的父子对象层交互处理的建筑物分级提取方法。该方法首先结合DSM数据先后两次应用多尺度分割生成父子对象层;然后,通过样本分级极值法将子对象层中的植被、水体及阴影剔除,并通过建筑物分级提取方法筛选建筑物种子节点;最后,将种子对象映射至父对象层中,结合上下文特征对父对象层中的建筑物种子对象进行区域生长,生长结果重新继承至子对象层中,完成建筑物提取。遥感影像建筑物提取实验结果显示,文中提出方法的F1-Score和IoU指标在实验区A中分别达到了95.9%和92.2%,在实验区B中分别达到了94.1%和92.2%,均优于支持向量机算法(Support Vector Machine,SVM)的结果,证明该方法可以有效提取遥感影像中复杂场景下的建筑物。

基于改进YOLOv5和DBSCAN聚类的变电站压板识别方法

本文提出了一种基于改进YOLOv5和DBSCN聚类方法的变电站压板智能识别方法,旨在实现压板开关状态的智能监控和高效管理。针对压板开关目标较小、分布密集的特点,对原生YOLOv5网络进行改进,增加检测头以提升小目标检测能力,并采用EIOU损失函数优化目标框定位精度。结合DBSCAN聚类方法,对检测出的目标框中心点进行聚类,并根据相对位置排列每个压板的目标框。通过比对“四表一指南”中的开合状态,实现所有压板开关的智能比对,该方法可提高监控准确性和管理效率,降低人工干预成本,为电力系统的安全稳定运行提供有力支持。

基于模型测试方法在模拟器客观评估中的应用

逼真度反映飞行模拟器与真实飞机特性的一致性程度。客观评估是一种通过模拟器与系统实际行为的测试比较来评估逼真度的工程方法。飞行模拟器分为工程模拟器和训练模拟器。用于飞行训练的训练模拟器构型很少变化,其测试用例由适航标准指导,而用于设计验证的工程模拟器,根据飞机研制进展经常需要升级或更改,其测试用例也会随之变化。在当今民用飞机技术日趋复杂的背景下,亟需高效方法开展这一类型模拟器的逼真度客观评估测试。在实验框架和系统实体结构和模型库框架的基础上,提出了一种基于模型测试的方法,在工程模拟器的客观评估的应用中,该方法可以实现测试用例的自动生成和执行,工作效率提升,流程具备灵活性和适应性,有助于在研飞机的定型或取证。

人机共站并行拆卸线平衡问题建模与混合教学优化算法

针对现有人机共站拆卸问题研究对任务间影响关系约束的不足,提出人机共站并行拆卸线平衡问题,以工作站开启数、空闲时间均衡指标、操作者总数和拆卸成本为优化目标,构建了其多目标混合整数规划模型。并提出一种混合教学优化算法求解,算法在原始教学优化算法的基础上融入自学操作和模拟退火操作,以保持种群多样性并避免算法陷入局部最优。应用数学规划软件LINGO精确求解所提问题的中小规模算例并与算法求解结果对比,验证了所建模型正确性与算法的有效性。最后,将所建模型与所提算法应用至大规模人机共站并行拆卸线实例中,通过与多种算法进行不同的对比试验,进一步验证了所提算法求解性能和求解质量的优越性。

作战概念及其建模研究综述

作战概念是未来智能化战争设计的关键,而作战概念建模运用语言、符号、表格、图形等对作战概念这一想象的真实战争系统进行抽象和简化描述,可为不同领域的专家提供沟通桥梁.梳理总结作战概念内涵、体系框架和开发等相关内容.分析基于模型的系统工程与概念建模,描述作战概念建模内涵,归纳其特征与原则,构建建模流程.探讨总结相关建模语言和方法的利弊及其在作战概念建模中的应用,并建立了一种作战概念建模的综合集成方法,以期能够为未来作战概念及其建模研究提供一定参考和借鉴。