Optimal Preventive Maintenance Policy with Consideration of Production Wait

In this paper, we consider the replacement of a single unit with catastrophic failure mode. Besides replaced at a preset time, the unit is also replaced at failure time or if it encounters a production wait and its age has reached a threshold. The joint preventive maintenance interval and threshold optimization problem are formulated with the objective of minimizing the expected cost per unit time in long run. A numerical example is presented to illustrate the applicability of the model.     

The use of hydrogen as a fuel for inland waterway units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.     

基于蛙鸣博弈的我国绿色修船产业发展研究

随着我国航运业的迅速发展,船舶修理行业得到快速提升,同时船舶修理中的环境污染及相应的保护措施也成为严峻问题。从某种意义上看修船中的环境问题可以看作是修船产业的经济现象,因此有可能从修船产业内寻求节能环保的利益驱动机制。借鉴蛙鸣博弈模型对传统修船生产方式与绿色生产方式(即清洁生产)展开分析,给出各种情况下的稳定策略,并结合博弈结果,针对性地给出对策和建议,以期对修船产业转型产生些许启示。     

GIS技术在采油老区新型城镇化建设和管理中的应用

城镇化和信息化是我国发展的两个主要趋势,采油老区的城镇化势在必行。随着城镇化发展的规模不断增大,传统的城镇管理手段很难满足时代的要求,文中讨论采油老区城镇建设的意义和面临的困难,指出GIS在新型城镇化建设中的作用,从不同领域讨论地理信息技术在城镇规划、建设管理中的应用。     

提高205000DWT散货船舾装先行率的方法与措施

以提高205000 DWT散货船舾装先行率铁舾件的舾装先行率为目标,通过分析影响舾装先行率的因素,提出优化方案并实船验证,最终实现了缩短坞期、减少大型吊机的使用量、降低现场施工环境的危险度、减少补涂及相关施工量,从而满足PSPC等相关施工标准的目标要求.     

提高交通建设安全生产监督水平的途径研究

通过对当前交通基础设施建设市场现状、从业人员组成和特点、安全生产管理存在的问题等方面进行分析,提出提高安全生产监督管理水平的途径。     

甲烷风电闭锁在铁路瓦斯隧道中的应用

瓦斯隧道施工过程中,实行瓦斯监测监控是一项重要的安全技术措施。为提高技术管理水平,隧道施工中已普遍采用瓦斯监测监控系统。新建兰渝铁路梅岭关高瓦斯隧道选用KJ101N型煤矿安全监测监控系统,此监控系统具有连续监测功能,能实现风电自动闭锁、瓦斯超限自动断电、闭锁,给地面调度、指挥中心提供连续实时的瓦斯、一氧化碳、风量等数据,增强了灾害预报预防能力,是保障安全生产的重要装备。在预防隧道瓦斯事故中发挥了重要作用。     

自适应步长的细菌觅食优化算法研究

细菌觅食优化算法是一种群集智能优化算法,该文详细分析了细菌觅食优化算法中最重要的趋向性操作,其中步长对算法的效率和精度有很大影响;根据菌群中细菌个体间的位置信息,设计了动态步长估值函数,自适应的调整步长.通过经典函数的测试,说明改进细菌觅食优化算法在收敛速度和精度上比原有算法有极大提高.     

造船行业施行清洁生产的研究

为提高原料和能源的利用效率,实现造船行业的绿色环保发展,更好的保护人和环境。尝试将清洁生产的理论与方法导入造船业,提出造船行业清洁生产的概念,分析船舶工业清洁生产的意义、内涵、模式与途径。认为在船舶工业推广清洁生产,创建绿色造船企业,开展节能、降耗和再生利用,引进环境管理体系,加强清洁生产管理,能够增强船舶工业核心竞争力,促进船舶工业可持续发展。     

应用回归分析的方法建立劳动定额数学模型的不适应性分析

研究目的:在建立劳动定额数学模型的过程中,寻找符合劳动定额专业特点的建模方式和检验指标。研究方法:采用对比的方法,对回归分析和曲线拟合进行比较。研究结果:找出了回归分析与曲线拟合的相同点和不同点,从而提出了建立劳动定额数学模型质量的检验指标。研究结论:曲线拟合的方法更接近于劳动定额专业特点。建议在建立劳动定额数学模型并检验其实用性及精确度时,采用曲线拟合误差指标,而不再使用回归分析指标。