Association rule learning to improve deficiency inspection in port state control

ABSTRACT

The inspection of foreign ships in national ports is a critical measure in port state control (PSC), preventing substandard ships from entering national ports. Multifarious inspection items, limited inspection time and inspector manpower are challenging PSC inspection. This research applies data mining to analyze historical PSC inspection records in Taiwan’s major ports to extract potential valuable information for PSC onboard inspections. Using the Apriori Algorithm, the analysis identifies many useful association rules among PSC deficiencies in terms of specific ship characteristics, such as ship types, societies, and flags. The general rules identified show that the items ‘Water/Weathertight conditions’ and ‘Fire safety’ are significantly related. Besides, in the analysis of the various ship types, several different rules are found. After comparing the analysis of ship types and ship societies, it can be observed that the association rules for specific ship types, such as oil tankers, have a better effect than those for individual ship societies do. These identified rules can not only help inspectors effectively spot the associated deficiencies, but also improve the efficiency of PSC inspection. The ports other than Taiwan’s ports can apply a similar analysis method to identify corresponding association rules suitable for their own inspections.     

基于船舶碰撞事故调查报告的人的因素数据挖掘

船舶碰撞事故发生率居高不下与人为失误有关，而人为失误的发生又受到包括个人因素、环境因素、船舶因素以及组织因素的影响。根据一般的事故统计数据能够初步识别出引发碰撞的人为失误行为，但要进一步建立影响因素与人为失误之间的对应关系却一直是令研究人员困惑的事情。一方面是因为缺少数据，另一方面是缺少方法。我们在收集100个碰撞事故调查报告的基础上，利用数据挖掘技术中的关联规则对人为失误与其影响因素之间的关系进行了挖掘，初步确定了船舶避碰过程中人为失误与引发因素之间的对应关系。     

Rough集理论及其在汽车故障诊断中的应用

Ｒｏｕｇｈ集理论是一种处理不确定或模糊的知识的重要工具。文章介绍了Ｒｏｕｇｈ集理论的概念和方法，提出了可以应用于汽车故障诊断领域的一些Ｒｏｕｇｈ集方法，并且用实例说明了Ｒｏｕｇｈ集方法在汽车故障领域中知识发现方面的具体应用。     

广州轨道交通沿线岩溶形成和发育特征及对隧道施工的影响

广州地区轨道交通沿线岩溶是在有利的地层条件、地质构造条件和水文地质条件下形成的。溶洞高度大多数小于3m,溶洞埋藏较浅,溶洞顶板较薄等。岩溶分布规律与发育程度主要受岩性、地质构造、地下水位变化等因素的控制。查明岩溶形成条件、分布规律和特征,对于隧道施工风险防范具有重要意义。     

关联规则挖掘在研究生个人学习计划制定中的应用

介绍了关联规则挖掘算法Apriori及其在研究生专业课程间的关联规则发现中的应用，所发现的规则用于辅助新研究生进行个人学习计划制定。可减少研究生在个人学习计划制定中的盲目性，提高所选课程与学科专业研究方向的吻合度。     

城市客车自动离合器接合规律仿真及应用

分析了城市客车离合器接合过程,设计了自动离合器的接合规律,计算了一档起步、行驶换档和爬坡行驶等行驶特性下自动离合器的控制参数,并运用Cruise软件进行了汽车建模和仿真。仿真结果表明,该接合规律在保证汽车加速性的条件下,达到了满足汽车起步平顺、减小摩擦功和降低冲击度等性能指标。     

船舶检验与规则规范分类

船舶及其产品的检验分为法定检验和入级检验。在法定检验规则中，重点介绍了IMO的公约、规则、决议和通函的性质和特点，将与船舶有关的ILO第92号、第133号公约与MLC2006进行了比较，列出了各国部分法定检验机构的缩写。在入级检验规范中，涉及IACS共同规范、HCSR、统一要求和统一解释，并简要阐明13个IACS会员船级社的中英文全称、缩写、网址和E-mail。值得注意的是，规则和规范均处于不断修正中，必须采用合同签字日已生效的现行有效文本。     

国际海事组织MEPC委员会第59次会议概览

国际海事组织下属的MEPC委员会第59次会议于2009年7月13日至17日在伦敦举行。本次会议对于MARPOL73/78公约的附则Ⅰ中油轮间海上转驳货油、残油（油泥）在船处理、为保护南极水域采取特殊措施的修正案分别获得通过和认可;附则VI中增加＂排放控制区域＂,＂挥发性有机化合物＂管理计划等提案也达到认可或通过。另外,涉及环保拆船、压载水处理,船舶噪声危害、人为因素、有害的船舶防污涂层等方面的提案都得到了认可和重视。对上述具体内容,文中进行了详细的归纳整理。     

A study on scantling formulae of plate members due to lateral pressure under the effect of axial loads

Existing rule scantling formulae of plate members are based on conventional plastic design theory, and do not necessarily reflect complicated plate bending phenomena under axial loads. In this study, we first formulated the effect of axial load on the fully plastic moment based on the von Mises yield criterion for longitudinally stiffened plate in addition to the well-known formula for transversely stiffened plate. In addition, we derived a theoretical formulation of the lateral pressure corresponding to 2-point hinge and 3-point hinge formation taking account of the effect of the additional lateral force due to the axial loads on the deflected plating, using a simple plate strip bending model assuming a long plate with a large aspect ratio.Then, a series of elastic-plastic FE analyses was carried out to verify the structural behavior and the effect of axial load on the plate plastic bending strength. The plate strength was evaluated based on the residual deflection criteria of two cases (0.26 mm and 4.0 mm), and the results were compared with the theoretical derivation. As a result, it was found that assumption of linear strength reduction to the axial stress can cover the transversely stiffened plate under compressive axial stress conservatively. As to the transversely stiffened plate under tensile axial stress and the longitudinally stiffened plate, the strength reduction was in accordance with the reduction in the fully plastic moment based on the von Mises yield criterion in the conservative side. Finally, based on the findings, the required plate thickness coefficients were proposed on an empirical basis both for transversely and longitudinally stiffened plate under compressive and tensile axial loads.     

无锡地铁运行引起上马墩站振动的现场试验研究

高频次的地铁运营引发的超量振动对于周边生活和工作造成了明显的负面影响,为了获取地铁诱发振动的传播规律,在无锡地区进行从车站到上盖物业的现场振动实测。在上马墩站搭建整套加速度信号振动测试系统,获取各测点3个方向时域加速度信号,分析结构在时域和频域的基本特征,对地铁运行造成上马墩站振动影响进行评价。研究发现： 1）垂向振动在通常情况下明显占优,横向、纵向振动相当; 2）上盖物业振动主要集中为25~50 Hz; 3）车站的Z振级接近规范规定白天限值,超出了夜间限值,有必要采取结构优化或减振措施对地铁运行引起的振动进行控制。