基于实船结构监测数据的异常检测及处理方法

目的 获得高质量实船结构监测数据,减少数据因外界干扰造成的异常现象,现开发一套面向真实海况的实船结构监测数据的异常处理方法。方法 将统计学中的Z-score异常检测方法与数据处理中常用的平均值计算法相结合,实现对船舶结构应力数据的异常处理。基于正常信号创建含有异常现象的验证数据,对新的异常处理方法进行精度验证。结果 相比Hampel滤波法、Smooth平滑函数等传统的信号处理方法,Z-score异常检测及平均值计算方法的异常处理精度最高,且以此为基础计算的结构信号统计值准确度较好。结论 Z-score异常检测及平均值计算方法可实现真实海况下的实船结构监测数据的异常处理,并在结构应力数据的价值挖掘上可提供有力支撑。     

垂直升船机初期火灾疏散路径人群流量分配研究∗

为合理分配垂直各疏散路径的人群流量,通过分析垂直升船机的结构特征,确定升船机综合使用电梯与楼梯进行垂直疏散的可行路径,分别计算从电梯向最近出口疏散、经楼梯向上游平台疏散、经楼梯向下游平台疏散等三条路径上的疏散时间,取三者较大值作为升船机垂直疏散时间,并以此时间最小化为目标函数,运用粒子群算法,仿真求解使用楼梯比例及向上游平台疏散比例等流量分配系数。结果表明:停靠高程∈[62,128]m时,楼梯使用比例可适当增大,使用楼梯向上游疏散比例为0;停靠高程∈[128,147]m时,楼梯使用比例可进一步增大;停靠高程∈[147,175]m时,楼梯使用比例可适当减小,使用楼梯向上游疏散比例为1,经流量分配后疏散时间被有效缩短。     

Two-Phase Transport Model for the Pyrolysis Process of a Vertical Wood Cylinder,Including the Surrounding Flow Field

This paper describes a mathematical model for the pyrolysis of a small dry pine wood cylinder. The computational domain is axisymmetric and involves the heating chamber, with the wood cylinder vertically situated in the centre of the chamber. The model simulates the laminar flow around the particle and the laminar flow inside the wood/char matrix by applying a two-phase transport model where the solid wood/char matrix acts as one phase and the various gases produced from the pyrolysis process is assembled in the other phase.

Convective, conductive and thermal radiation transfer modes are included in the model. A two-step pyrolysis reaction scheme is used for the modelling of the conversion from wood to tar and gas. Both the thermal conductivity and the permeability of the wood/char matrix are modelled anisotropically in order to capture the directional differences in heat and mass transport, existing in real wood.

Results from simulations are compared with measurements from literature for the centre core solid temperature and the conversion from wood to char, tar and pyrolysis gas in the particle during heating. The results show very good agreement with the measured temperature profile. The simulated conversion profile shows an overall good agreement with the measurements, however with discrepancies in the early stage of the process. Besides the successful validation with the experimental data, it provides us with all the details of the distribution of the migrating pyrolysis gas and tar, the temperature, the velocity flow field and pressure in the wood/char cylinder.     

船舶引航员可靠性评价体系研究

为有效预测船舶引航员作业中的安全可靠性,预防引航事故,基于其职业特点,提出了情绪状态、注意力、心情状态等动态和静态评价指标各5个,并采用专家评价或自评的方式对指标赋值。采用专家调查、DEMATEL方法,研究、验证了指标的合适性和指标间关系的正确性,并确定了各指标的权重。结果表明:引航员心情状态的权重最大(0.123 6),基本生理素质的权重最小(0.082 6);最后通过案例分析,得到某一级引航员的可靠性值为91.342 5。引航员在工作中有良好的心理和生理状态以及良好的操作技能,有助于引航员可靠性的提高,从而减少引航事故的发生。     

Efficacy of a Voluntary Area to Be Avoided to Reduce Risk of Lethal Vessel Strikes to Endangered Whales

Abstract: Ocean‐going vessels pose a threat to large whales worldwide and are responsible for the majority of reported deaths diagnosed among endangered North Atlantic right whales (Eubalaena glacialis). Various conservation policies have been implemented to reduce vessel‐strike mortality in this species. The International Maritime Organization adopted the Roseway Basin Area to be avoided on the Scotian Shelf as a voluntary conservation initiative to reduce the risk of lethal vessel strikes to right whales. We initiated the Vessel Avoidance & Conservation Area Transit Experiment to evaluate the efficacy of this initiative because the effectiveness of the avoidance scheme in reducing risk without the imposition of vessel‐speed restrictions depends entirely on vessel‐operator compliance. Using a network of automatic identification system receivers, we collected static, dynamic, and voyage‐related vessel data in near real time from the Roseway Basin region for 12 months before and 6 months after the implementation of the area to be avoided. Using pre‐ and post‐implementation vessel navigation and speed data, along with right whale sightings per unit effort data, all resolved at 3′N latitude by 3′W longitude, we estimated the post‐implementation change in risk of lethal vessel strikes. Estimates of vessel‐operator voluntary compliance ranged from 57% to 87% and stabilized at 71% within the first 5 months of implementation. Our estimates showed an 82% reduction in the risk of lethal vessel strikes to right whales due to vessel‐operator compliance. We conclude that the high level of compliance achieved with this voluntary conservation initiative occurred because the area to be avoided was adopted by the International Maritime Organization. Our results demonstrate that international shipping interests are able and willing to voluntarily alter course to protect endangered whales.     

船舶压载水处理技术的应用与研究进展

船舶压载水在船舶航行的安全保障和稳定性提升方面起着至关重要的作用,然而压载水直接排放也造成了海洋污染和外来生物入侵等负面影响.通过研究各国压载水的水质特点及处理现状,总结了当前常用于压载水处理的物理、化学和生物等方法及其原理和特点,介绍了几种现阶段中国自主开发的压载水处理技术和装置以及对各装置的性能及特点进行分析,并提出了各压载水处理设备在使用中应注意的问题.通过总结近年压载水处理所产生的问题对未来压载水处理领域提出一些建议.     

舰船结冰预报方法研究

目的：为在可能导致舰船结冰的海区航行的舰船提供结冰预报模型,保证船舶的航行安全。方法基于结冰表面热平衡理论,给出舰船结冰预报模型和预报工具。结果给出中等舰船结冰危险等级,结冰强度小于1.5 t/h为弱结冰风险等级,1.5～4.0 t/h时为中等结冰风险等级,大于4.0 t/h为强结冰风险等级。结论提出的结冰预报方法和工具简便易行,对于保障舰船在高纬海区的安全航行具有重大意义。     

基于二维灰云模型的LNG动力船航行过程风险推理*

针对风险多维属性问题及船舶航行多种风险表现,提出基于二维灰云模型的LNG动力船航行过程风险推理方法。针对LNG使用及船舶航行2种作业方式,采用系统方法识别安全风险影响因素体系,确定2种作业方式下各风险体系指标变化权重,描述LNG动力船航行过程中LNG使用和船舶航行发生事故概率及后果;通过引入云模型,综合计算2种作业方式下概率及后果组合风险,并采用灰云推理2种作业方式同时存在时LNG动力船航行过程风险。结果表明:LNG动力船航行过程中LNG使用和船舶航行风险耦合,风险程度受控;二维灰云模型可有效分析多维属性下风险评估问题,以及不同作业下风险耦合作用。研究结果可为船舶航行过程风险定量评估提供依据。     

非线性在特大型船闸运行水污染控制中的应用

应用非线性动力学、分形理论、混沌学，研究了特大型船闸运行水污染系统，结合葛洲坝特大型船闸运行系统自组织特征和水污染事件，论述了船闸水污染非线性、分形特征，建立了动力方程、水质预测预报模型，指出常规理论方法研究中存在的问题，提出了水污染系统非线性研究是今后着重需要深入探讨研究的领域，具有重要的实用价值。     

2013年中国海域船舶大气污染物排放对空气质量的影响

基于2013年中国海域船舶排放清单和空气质量数值模拟平台（WRF-SMOKE-CMAQ）,利用敏感性分析方法定量识别了中国海域船舶排放对沿海地区空气质量的影响特征. 结果表明：船舶排放对不同污染物的贡献特征空间差异显著,就SO₂、NO₂和PM_2.5而言,在沿海省份的年均贡献率分别为5%、7%、2%（1.1、1.7、0.9 μg·m^-3）,其中,珠三角和长三角地区受影响较大,SO₂、NO₂和PM_2.5贡献分别可达30%、31%、8%（7.7、9.2、2.7 μg·m^-3）和14%、13%、4%（3.7、5.3、1.9 μg·m^-3）.其次,船舶排放对空气质量影响季节性差异显著,尤其表现在PM_2.5的空间分布上,三大城市群中,船舶排放对污染物贡献的季节间最大差异倍数为SO₂（1.3~2.0）,NO₂（1.2~4.0）,PM_2.5（1.8~7.5）.值得关注的是,船舶排放对PM_2.5的浓度贡献表现出了明显的区域性（长距离传输）和复合性.本研究结果,一方面弥补了我国船舶排放对空气质量影响的量化特征认识不足,另一方面可为后续船舶排放的健康影响及控制费效分析等评估研究提供数据支撑.