Modeling design of military equipment operational concepts by MBSE北大核心CSCD

［Objectives］In order to give full play to role of "operational concepts" in the engineering process of military equipment development, it is necessary to understand and form standardized operational concept documents (OCD), and study the modeling design of OCD in order to implement the transformation of the system engineering process from document-centric to model-centric. ［Methods］This study analyzes the US military's definition of operational concepts and introduces its hierarchical operational concepts, especially the bottom level ConOps or OpsCon, usually as a part of equipment acquisition and requirement engineering. Lessons are then drawn from the relevant theories and standards such as IEEE 29148:2018 and ANSI/AIAA G-043B-2018 of the operational concepts document outline in order to design the specifications of the OCD. Finally, key technologies are studied, including SysML-based OpsCon modeling, UML Profile-based OpsCon framework design and MSDL/C-BML-based operational scenario development.［Result］The results indicate the effectiveness of implementing the modeling design of OCDs. ［Conclusions］In the process of equipment requirement engineering, the results of this study can help to improve the efficiency of equipment requirement demonstration through an ambiguous operational concept model and an engineering environment for all stakeholders of the system. © 2022 Journal of Clinical Hepatology. All rights reserved.     

基于组合校正的城市轨道交通列车轮轨黏着控制方法研究

为提高城市轨道交通列车轮轨黏着力的控制,针对传统组合校正法存在的缺点,对参考速度进行延时补偿、筛选及步长限制,尽可能保证参考速度的准确性;对加速度提取采用低通加高通滤波器的方法,以降低噪声影响;黏着控制过程中,根据设定周期时间内速度差估算当前轨面黏着情况,实时调整下一周期判据阈值;根据上一调节周期触发空转时刻锁存转矩和当前加速度,以及转速差采用分段斜率的方法进行转矩调节。试验结果表明:上述控制方法转矩波动小,列车运行平稳,黏着利用率得到有效提高。     

阿布扎比哈里发港集装箱码头二期项目平面工艺设计要点

阿布扎比哈里发港集装箱码头二期项目是“一带一路”重要节点工程。根据集装箱自动化码头建设要求,研究了自动化模式选择、平面和工艺布置方案。通过对自动化程度、交通组织、堆场能力、人员投入、建设工期、工程投资等多方面比选,确定选用堆场平行码头布置的自动化码头(ARMG+集卡)模式。通过集约布置辅助设施、单悬臂ARMG背靠背布置模式等扩大堆场能力。方案技术可靠、先进、可拓展性强,建设周期短,工程投资低。     

High-Speed Rail Operations on an Existing Network: An Assessment Model for China

High-speed rail operations have the potential to reduce the long-term decline in rail passenger travel demand for the medium to long distance inter-urban markets. Such decline has been evident through most of the industrialized countries where air and road transport tend to be the dominant modes. In China, the operations of long distance high-speed rail on fully dedicated track is not very easy to implement, due to the high proportion of passengers who travel between high-speed and conventional railways. An alternative approach would be to allow for mixed operations with trains of various speeds on the same track. This article puts forward a simulation model designed to allow an evaluation of the most efficient distance for high-speed rail operations under mixed train speed scenarios. The model takes into account the main operating parameters such as passenger volumes, train speeds, capital and maintenance costs, train operating costs and energy consumption. The distance of high-speed train running on conventional rail that will yield the most economic benefit can be estimated using the model. The article includes the results of using the model for a specific example. It is concluded that large-scale high-speed trains have the potential to be successfully operated on conventional rail networks.     

谈高职生思想政治教育工作的系统性

针对目前高职生思想政治教育研究存在的问题,本文从教育主体、教育对象、教育内容、方式手段四个方面,全面阐释了新形势下高职生思想政治教育工作的内涵,形成系统,以期有益于高职院校思想政治工作实践。     

40万吨矿砂船货舱段局部强度分析

介绍了基于DNV规范对一艘40万吨矿砂船的结构强度进行有限元分析.应用DNV的Sesam和Nauticus Hull软件对该船屈服、屈曲强度进行分析评估,并依据结果对船体结构型式和尺寸进行了优化和加强.其分析结果与加强方案对超大型矿砂船结构的强度分析具有一定的参考价值.     

使用30°楔形防松螺纹安装扭矩的建议

为明确30°楔形防松螺纹在同样的施加扭矩下所获得的轴力。试验了30°楔形防松螺纹和普通螺纹经振动防松试验轴力的衰减情况和同扭矩下扭矩系数及轴力的比对试验。从而获得在施加相同扭矩下,30°楔形防松螺纹所获得的轴力比普通螺纹所获得的轴力低。     

知识管理中科技成果管理与知识产权保护问题的研究

本文在分析知识管理特征的基础上,阐明了知识管理体系中科技成果管理与知识产权保护的目的及意义,然后阐述了两者之间的相同点与不同点关系,最后提出实施知识管理的战略对策。     

基于3D打印技术的两轴变速器教具开发

基于3D打印技术的灵活性、方便性等优点,3D打印技术在许多领域得到广泛的应用;因此引来诸多关注,并在自制教具模型方面得到推广。目前汽车变速器空间结构复杂、难以拆卸,所以在教学中存在抽象、枯燥等现象。为了提高"教、学、做"一体化教学效果,利用3D打印技术打印变速器教具模型,满足汽车专业教学需求。同时提高了学生的实践技能、还为教学节约了成本,还提高了课堂的趣味性及效率。