数字开关电源技术的发展分析

介绍数字开关电源的性能及其特点,简述数字开关电源、电源产品、应用,论述数字开关电源的发展分析。     

舰艇原动机及其调速系统的研究

本文介绍了汽轮机、柴油机的原动机及调速系统的特性和模型。基于DCS500B实现了汽轮机、柴油机的原动机及调速系统外特性模拟。     

斯里兰卡Hambantota港口项目港址选择及一期工程设计介绍

对斯里兰卡Hambantota港口项目工程港址选择、港口功能定位、一期工程平面布置,泻湖内建设大型围堰,及在干地施工条件下实施的码头工程进行介绍.     

转发式GPS干扰机抗反辐射攻击武器研究

通过分析GPS导航定位系统的定位原理、特点与缺陷,提出转发式GPS干扰机抗反辐射攻击武器思路,采用仿真方法具体论证了转发式干扰信号干扰j欺骗GPS接收机的可行性,论证了转发式GPS干扰机抗反辐射攻击武器的可行性。     

Fault diagnosis of steam power system based on convolutional neural network北大核心CSCD

[Objectives]In order to improve the fault diagnosis level of marine power systems, this paper studies the real-time fault diagnosis of a marine supercharged boiler based on a convolutional neural network (CNN).[Methods]First, the simulation program of the marine supercharged boiler is developed based on the GSE platform, and the simulation fault data is obtained. The fault diagnosis model of the boiler is then established using the CNN method. Next, through the change trends of temperature, flow and other parameters, combined with a priori knowledge and the machine learning method, fault identification is carried out. Lastly, the performance of the method is evaluated against criteria such as confusion matrix and accuracy. [Results]According to the comparison results between the feature extracted dataset and the original dataset, the stability of the model output results and the generalization ability of the model are optimized and improved, with an overall fault classification accuracy reaching 99.53%.[Conclusion]The results of this study can provide valuable references for the intelligent monitoring of marine power systems. © 2022 Chinese Medical Journals Publishing House Co.Ltd. All rights reserved.     

某船舶推进系统的固有振动特性计算与分析

以某船整个推进系统为研究对象,基于有限元方法,建立了推进系统的有限元模型,计算分析了该推进系统固有振动特性,得到其固有频率和固有振型.结果分析表明:该推进系统的模态振型以螺旋桨和艉轴弯曲变形为主,在52.2 r/min的转速下,该推进系统发生共振.这为推进系统的结构优化提供了参考.     

基于FAHP法的造船起重机结构安全性评价研究

针对目前国内外造船起重机安全性评价方法的不足,研究基于模糊层次综合评判法(FAHP)的造船起重机金属结构安全性评价方法,采用层次分析法(AHP)确定指标权重,将模糊综合评判理论运用于起重机金属结构综合评估中。以造船门座起重机为例,建立多指标、多层次安全性评价模型,对指标状态值进行无量纲化处理,运用层次分析法确定权重值,采用模糊综合评判理论计算各层评价值,并最终得到整机金属结构安全指数,为起重机使用企业和特检部门开展工作提供参考依据。     

滑行艇高速航行时的数值模拟(英文)

Planing vessels are applied widely in civil and military situations.Due to their high speed,the motion of planning vessels is complex.In order to predict the motion of planning vessels,it is important to analyze the hydrodynamic performance of planning vessels at high speeds.The computational fluid dynamic method(CFD) has been proposed to calculate hydrodynamic performance of planning vessels.However,in most traditional CFD approaches,model tests or empirical formulas are needed to obtain the running attitude of the planing vessels before calculation.This paper presents a new CFD method to calculate hydrodynamic forces of planing vessels.The numerical method was based on Reynolds-Averaged Navier-Stokes(RANS) equations.The volume of fluid(VOF) method and the six-degrees-of-freedom equation were applied.An effective process was introduced to solve the numerical divergence problem in numerical simulation.Compared with experimental results,numerical simulation results indicate that both the running attitude and hydrodynamic performance can be predicted well at high speeds.     

千岛湖大桥V形墩有限元分析和施工研究

介绍了千岛湖大桥主桥的墩座、V形墩斜腿、箱梁、箱梁预应力各部分的结构设计方案。通过对大桥主桥结构进行整体平面杆系有限元分析及对墩梁结合部进行空间有限元分析,验证整体结构和局部结构的受力合理性,提出了全桥施工方案,进一步确保V形墩结构的安全和质量。     

基于龙芯的Windows软件运行环境的设计与实现

龙芯处理器在国产处理器市场占有重要地位。由于龙芯采用的是MIPS指令集且主要支持Linux操作系统,然而目前在该平台上的应用软件还相对匮乏,且很多传统Windows软件也无法在该平台上直接运行,这使得龙芯处理器的推广与应用受到了影响。针对这一问题,提出了一种在龙芯平台上基于Wine来提供Windows 虚拟执行环境,并通过将Wine和Bochs模拟器相结合完成X86指令集到MIPS指令集翻译的解决方案。该方案能够实现Windows程序在零修改情况下直接运行在龙芯平台上,可支持Delphi ,C,C＋＋等多种语言开发的程序,以及网络、数据库等多种功能。测试表明：该系统运行稳定,但还存在不可忽略的性能影响。