运动舰船的电场测量

从理论和实验上对起源于防腐措施的舰船电场已进行了一些研究,但主要是针对近场,实测也是在静态进行．对运动舰船的电场分布、数量级及信号形式尚未见到文献报道．作者根据一次对海上运动舰船的电场测量结果,对上述问题作了一些研究．依据实验现象和测量到的信号特征,提出初步理论分析．理论分析与实验数据基本符合,说明运动舰船产生的感应电场是可以测量的．     

基于主动式轴接地系统的舰船轴频电场抵消方法

为减小轴频电场信号,基于轴频电场产生的机理对主动式轴接地(active shaft grounding,ASG)系统的原理进行了分析,并自主研制了原理样机,完成了实验室的船模试验。试验验证结果表明:所研制的ASG系统能有效地抑制滑环和碳刷接触电阻变化所引起的轴频电场信号,抵消效果可达90%以上。     

基于响应平面法的压力容器可靠性评定

针对压力容器制造、使用过程中各种参数的不确定性,提出了一种基于响应平面的随机分析方法.根据某压力容器的结构特点,确定性有限元分析采用了接触有限元,结合中心组合抽样设计构建了容器最大应力的响应平面,以此为基础对压力容器应力分布进行了随机分析.可靠性分析中引入应力—强度干涉模型,并分别对容器壁面和接管处进行了可靠性评定.实...     

基于探雷信息的火箭深弹炸雷效能研究

针对火箭深弹传统炸雷方式中存在的盲目性、危险性及耗弹量大等问题,提出了火箭深弹与探雷声纳协同定点炸除水雷的方法,建立了基于随机模拟的火箭深弹炸雷效能评估模型。实例解算结果表明,火箭深弹对水雷毁伤概率随着射距的增加而增大;在同一射距下,毁伤概率随射向与探测方向夹角的增加而增大,但在最优(大)夹角附近毁伤概率变化不大。通过该模型能有效解算出火箭深弹对水雷的毁伤效果,进而得到最优射击诸元和最大毁伤概率,对火箭深弹炸雷技术实施提供了理论基础。     

一种基于广义Hough变换的遥感图像船舶横波自动检测与速度估计方法

从Kelvin横波航迹的形成原理出发,详细推导了Kelvin横波波峰模型,提出一种基于广义Hough变换的遥感图像船舶横波自动检测方法,取得了较好的检测效果,并依据检测结果对船舶速度进行了估计。所述方法对海上船舶运输和港口管理等具有重要意义。     

Quay crane scheduling at container terminals to minimize the maximum relative tardiness of vessel departures

In this paper, we study the problem of scheduling quay cranes (QCs) at container terminals where incoming vessels have different ready times. The objective is to minimize the maximum relative tardiness of vessel departures. The problem can be formulated as a mixed integer linear programming (MILP) model of large size that is difficult to solve directly. We propose a heuristic decomposition approach to breakdown the problem into two smaller, linked models, the vessel‐level and the berth‐level models. With the same berth‐level model, two heuristic methods are developed using different vessel‐level models. Computational experiments show that the proposed approach is effective and efficient. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

Transit vessel scheduling

A transit vessel traffic scheduling algorithm has been developed to limit the negative effects on cargo volume throughput in two‐way waterways where separation distances between transiting vessels must be maintained and passage restrictions may hold. It runs in time that is polynomial in the number of ships involved in the computation and finds schedules which increase the utilization of waterways. Three examples illustrate its use. The first example is situated in the Sunda Strait where the algorithm is used to enhance the safety of merchant shipping against a terrorist threat. It illustrates important features of the algorithm and demonstrates how it can be used with cross traffic. The second example is situated in the Strait of Istanbul and offers a comparison between the developed algorithm and the transit vessel scheduling algorithm of Ulusçu et al., J Navig 62 (2009), 59–77. This was done using a plausible model of the Strait of Istanbul. The third and last example shows how the algorithm can be used to schedule transit vessel traffic in two‐way waterways with junctions. This feature is especially useful in congested waters with a high risk of collisions like the Inland Sea of Japan. An extreme test case proves that the developed algorithm is a practical algorithm ready for such use. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 225–248, 2017     

Study on dynamic response of multi-degree-of-freedom explosion vessel system under impact load

In order to study the dynamic response and calculate the axial dynamic coefficient of the monolayer cylindrical explosion vessel, the wall of vessel is simplified as a multi-degree-of-freedom (MDoF) undamped elastic foundation beam. Decoupling the coupled motion equation and using Duhamel's integrals, the solutions in generalized coordinates of the equations under exponentially decaying loads, square wave loads and triangular wave loads are calculated. These solutions are consistent in form with the solutions of single-degree-of-freedom (SDoF) undamped forced vibration simplified model. Based on the model, equivalent MDoF design method (also called MDoF dynamic coefficient method) of cylindrical explosion vessel is proposed. The traditional method can only predict the dynamic coefficient of torus portion around the explosion center, but this method can predict that of the vessel wall at any axial n dividing point position. It is verified that the prediction accuracy of this model is greatly improved compared with the SDoF model by comparing the results of this model with SDoF model and numerical simulation in different working conditions. However, the prediction accuracy decreases as the scaled distance decreases and approaches the end of the vessel, which is related to the accuracy of the empirical formula of the implosion load, the simplification of the explosion load direction, the boundary conditions, and the loading time difference.     

基于粒子滤波改进的VTS微弱目标检测前跟踪算法

舰船交通服务系统是民用雷达的信息集成系统,探测微弱目标存在RCS小、回波弱、杂波强等问题,导致信噪比低,难以实现有效检测跟踪。基于粒子滤波的检测前跟踪技术对低信噪比下微弱目标信息积累和探测有良好效果。通过采集单设备实测数据,构建遗忘因子和收敛因子以增加重采样的效率,引入虚拟采样保持粒子的多样性,提升粒子滤波对微弱目标的探测能力。仿真试验表明,改进后的算法可实现舰船交通服务系统对微弱目标的有效探测,并能获得较精准的目标状态估计值。     

几种排水型高性能船阻力性能对比研究

采用阻力理论计算方法,以高速圆舭艇的阻力性能为基准,对高速圆舭艇、深V型船、穿浪双体船以及高速三体船的阻力性能进行了对比研究,对比较结果进行了分析,给出了各船型的最适用航速范围.