船用低速柴油机数字电子调速器仿真研究

根据数字电子调速器的设计原理,在12K98MCC柴油机模型基础上,对数字电子调速器进行仿真研究,仿真实验采用VB编程语言,建立调速器模型,采用数字PID改进算法进行仿真实验,实验结果满足船用低速柴油机调速器性能要求。     

基于小生境遗传算法的单体船船型参数优化

针对船型参数优化中变量众多的特点,提出了一种基于小生境遗传算法和Holtrop总阻力计算公式的单体船船型参数优化方法.该方法中以总阻力作为目标函数,以主要船型参数为优化变量,在保持排水量不变的情况下优化主要船型参数,得出修长系数、水线面系数和宽吃水比均能收敛到相应的临界值,因此优化时可优先确定这些参数值.采用该方法对DTMB5415船的船型参数进行了优化,结果显示优化后的船型总阻力性能要明显优于原船型.该方法对于单体船船型参数优化具有较强的实用性.     

Routing and scheduling of RoRo ships with stowage constraints

Roll-on/Roll-off ships are used for international transport of vehicles and other rolling equipment. We consider the problem where a ship sails between two geographical regions, picking up cargo in the first and making deliveries to the second. Several variations are considered with optional cargoes, flexible cargo quantities, and ship stability restrictions. Decisions must be made regarding the route and schedule of the ship as well as the stowage of cargo onboard. The problem is modeled as a mixed integer program, which has been solved using Xpress. In addition, a tailor made heuristic procedure is built using components from tabu search and squeaky wheel optimization. Extensive computational results are presented, showing that the heuristic is able to handle realistically sized problem instances.     

Bus arrival time prediction at bus stop with multiple routes

Provision of accurate bus arrival information is vital to passengers for reducing their anxieties and waiting times at bus stop. This paper proposes models to predict bus arrival times at the same bus stop but with different routes. In the proposed models, bus running times of multiple routes are used for predicting the bus arrival time of each of these bus routes. Several methods, which include support vector machine (SVM), artificial neural network (ANN), k nearest neighbours algorithm (k-NN) and linear regression (LR), are adopted for the bus arrival time prediction. Observation surveys are conducted to collect bus running and arrival time data for validation of the proposed models. The results show that the proposed models are more accurate than the models based on the bus running times of single route. Moreover, it is found that the SVM model performs the best among the four proposed models for predicting the bus arrival times at bus stop with multiple routes.     

基于高频特性的发电机定子匝间短路故障信号检测

本文探讨了一种利用发电机定子匝间短路时产生的高频瞬时电压和电流进行故障检测的新方法,该方法通过对发电机定子匝间短路时因内部对称性被破坏而产生的高频瞬时电流和电压进行小波分析,找出判定故障的特征.通过仿真模拟与研究,证明发电机定子匝间短路时的高频瞬时电流是可以做为故障特征来判定的.     

船用磁悬浮隔振器建模和鲁棒性研究

振动噪声是影响海军舰船战斗力的一个重要因素,本文针对舰船舱室的特殊应用环境,得到了影响隔振器稳定性的主要外部因素是环境噪声干扰和冲击干扰,采用实验建模得到的磁悬浮主动隔振器初级通道和次级通道脉冲响应模型进行了滤波x-LMS算法控制下的鲁棒性仿真。仿真结果验证了脉冲响应模型的有效性,也证明了磁悬浮主动隔振器具有很强的鲁棒性。     

基于FPGA的水声信号检测系统设计

结合阵列信号处理技术,应用工程化的MUSIC算法,本文设计了一套基于FPGA的水声信号检测系统,对某些声纳检测系统的设计有一定参考价值。     

应用规则引擎构建舰艇作战决策系统方法研究

针对开发作战决策系统存在的问题,提出了基于规则引擎构建作战决策系统的方法。该方法使用开源Java规则引擎Drools作为决策系统的推理机,使决策规则与其它仿真软件代码分开,显著提高了系统开发效率,降低了系统维护的复杂度。Drools采用面向对象系统增强并优化的Rete算法实现推理机的模式匹配,可满足规则复杂的作战系统对决策时间的要求。实验表明,该方法能很好地完成复杂决策系统的构建。     

OFDM系统中定时同步算法的研究

正交频分复用（OFDM）对同步偏差十分敏感,同步偏差的产生会使OFDM系统性能大大降低。通过对训练符号在时域乘以特殊伪随机序列来消除定时同步中的峰值平台问题,仿真结果表明,与传统算法相比,改进算法在同步位置具有很尖锐的峰值,同步性能更好,符号定时更精确。     

基于变步长LMS的频域干扰抑制算法的研究

基于对时域变步长LMS算法、频域块LMS算法的研究分析,给出了一种新的基于变步长频域块LMS的干扰抑制算法,仿真结果和分析表明能实现更好的收敛速度和更小的有用信号损失,并且计算复杂度低,利于工程实现。