考虑内腔空气影响的高速磁浮轨道箱梁日照温度场研究

高速磁浮混凝土轨道梁在日照作用下温度分布不均匀,易引起梁体变形、开裂,影响行车安全.本文以上海浦东地区的气候条件为基础,研究了日照辐射下高速磁浮混凝土轨道箱梁的温度分布规律.首先基于固体传热和流体传热理论计算了浦东地区的太阳辐射值,然后建立了混凝土轨道箱梁有限元模型,并在考虑箱梁内腔空气传热效应的前提下计算了轨道梁整体...     

CRM中Apriori 算法的应用研究

Apriori算法作为一种典型的关联规则算法,将其应用在CRM中,对于促进CRM进一步向智能化发展,提升CRM价值起到非常重要的作用.本文从关联规则的概念、算法着手,介绍关联规则的概念与关联规则的几种方法;然后对Apriori算法的基本原则、方法的步骤,以及在CRM中应用的流程进行了论述;最后结合例子对Apriori算法的应用进行了探讨,介绍了具体的应用方法以及应用范围.     

乘客触发全自动驾驶列车车门紧急手柄的防护措施研究

针对乘客触发全自动驾驶列车车门紧急手柄的情况,分析车门及其紧急装置的特性,在车载ATC和车辆接口中增加保持门关闭信号作为车门打开的最终授权,通过研究各种场景下车载ATC和车辆之间信号或信息的时序,保持门关闭信号可以对触发车门紧急手柄的情况起到防护作用.     

Experimental study of drillship resistance performance in open and closed state of moonpool北大核心CSCD

[Objective] This paper carries out an experimental study of a multi-function dirllship model with moonpool structure in towing tank, aiming at analyzing the effects of the moonpool structure on the ship resistance in open and closure condition.[Methods]Taking a dirllship as the research object, the ship motion response in regular and irregular waves is investigated. The resistance of the ship in hydrostatic water and waves is measured with tension sensors, and the acceleration characteristics of the bow, midship and stern are analyzed by acceleration sensors.[Results]The results indicate that hull resistance under light load conditions is greater when open moonpool, while hydrostatic water resistance with closed moonpool is greater under design load conditions. The closed moonpool in regular waves reduces stern acceleration by 58.2%, bow resistance by 46.7% and heave response by 41.8%. The peak of resistance at the bow in irregular waves is about ten times higher than that at the stern, and the peak of resistance occurs more often when the moonpool is open at the same time.[Conclusions]The experimental study shows that the difference in load conditions changes the waterplane area and affects the hull resistance in hyrostatic water. In contrast, the closure of the moonpool not only reduces acceleration and resistance, but also improves surge and heave. As such, this paper can provide references for the structural design of drillships with moonpools. © 2023 Journal of Nanjing Agricultural University. All rights reserved.