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1.
针对集装箱港区陆域土地集约化利用问题,结合行业规范、相关规划布置理论,采用数值计算、估算、统计相结合的方法,提出了一种用于港区陆域面积估算的公式。选取国内部分港区进行验证,基于假设的计算结果与实际用地面积相比偏差在-19. 63%~24. 08%,其中总偏差在15%、10%、5%以内的数量分别占样本总数量的80%、71%和43%,验证了公式的有效性。基于公式参数讨论和典型港区共性因素分析,认为港区陆域土地集约利用可采取以下措施:提高设备覆盖率,提高水-水中转比例,布置自动化堆场,采用新一代信息技术提高货物周转速度,布置集约化辅助生产设施,优化道路系统减少道路面积占比等。  相似文献   

2.
Marine ecosystem models are becoming increasingly complex and sophisticated, and are being used to estimate the effects of future changes in the earth system with a view to informing important policy decisions. Despite their potential importance, far too little attention has been, and is generally, paid to model errors and the extent to which model outputs actually relate to real-world processes. With the increasing complexity of the models themselves comes an increasing complexity among model results. If we are to develop useful modelling tools for the marine environment we need to be able to understand and quantify the uncertainties inherent in the simulations. Analysing errors within highly multivariate model outputs, and relating them to even more complex and multivariate observational data, are not trivial tasks. Here we describe the application of a series of techniques, including a 2-stage self-organising map (SOM), non-parametric multivariate analysis, and error statistics, to a complex spatio-temporal model run for the period 1988–1989 in the Southern North Sea, coinciding with the North Sea Project which collected a wealth of observational data. We use model output, large spatio-temporally resolved data sets and a combination of methodologies (SOM, MDS, uncertainty metrics) to simplify the problem and to provide tractable information on model performance. The use of a SOM as a clustering tool allows us to simplify the dimensions of the problem while the use of MDS on independent data grouped according to the SOM classification allows us to validate the SOM. The combination of classification and uncertainty metrics allows us to pinpoint the variables and associated processes which require attention in each region. We recommend the use of this combination of techniques for simplifying complex comparisons of model outputs with real data, and analysis of error distributions.  相似文献   

3.
Shipping is a high-risk industry. The aims of this conceptual paper are to build a framework showing in what way safety onboard is influenced by trust, and to identify the main obstacles to trust-building within the shipping industry. To meet these aims, a literature review and a pilot study are conducted. The study shows that interpersonal trust from employees to managers, and among seafarers, seems to be a prerequisite and an indirect factor, or mediating variable, that influence safety-related organizational outcomes positively and seems to reduce human errors. Interpersonal trust seems to be most valuable in weak situations, which means situations that are not critical and when no exact guidance or incentives to behave in a particular way are needed. An optimal level of trust exists onboard, and because of the high-risk environment, this optimal level of trust is expected to be relatively high. The main obstacles to trust within the shipping industry seem to be the dual employment practice, the physical distance between onboard, crewing agency and onshore, the reduced competence requirements, the frequent reorganization of the crew and multiculturalism. The paper contributes to the trust and to the safety literature by a new framework and to the development of 11 hypotheses on trust and safety. Finally, the paper is indicating that trust may be the missing piece in the safety puzzle.  相似文献   

4.
大型水面舰艇生命力快速评估方法研究   总被引:2,自引:1,他引:1  
大型水面舰艇的生命力评估对于预见风险,采取措施减小生命力损失,提高作战能力具有重要意义。针对其体积庞大的特点,从强度角度入手采用类似于损管的分块方法,将主船体分为若干区域,沿船长及高度方向设定不同分块的参数。随机模拟被击中的位置以及武器数量和种类,计算相应情况下的破坏程度。设立评判准则分析生命力损失的情况,并且计算发生概率。通过以上措施,初步形成了快速评估生命力的方法,可以迅速地对大型水面舰艇的生命力状况做出估计,便于软件实现和应用。  相似文献   

5.
在双向曲率板线加热成型及滚压成型的工艺设计研究中,一项十分重要的工作就是依据所需目标形状计算应变分布并以此确定加工路径和工艺参数,因此应变分布计算的精度直接影响到加工路径和工艺参数的准确性.本文介绍了一种基于力学方法的应变分布计算方法,首先对平板施加节点位移场进行弹塑性计算,由于存在回弹现象,需对节点位移场进行反变形修正,本文将得到的形状与目标进行对比后,再利用两者偏差对位移场进行迭代修正,直到两者偏差满足精度要求,最后将得到的应变场以初应变的形式输入到平板模型上,用初应变法的结果对应变的计算方法进行验证,证明该方法的精度,为后续加工路径和工艺参数的准确确定提供基础.  相似文献   

6.
为了提高造船效率、降低造船成本、提高造船质量,造船行业需要引入先进的智能制造理念。船舶制造作为典型的离散型制造行业,其传统的船舶设计、制造模式在一定程度上限制了智能制造技术的大范围推广应用,从船体零部件标准化设计角度,研究如何利用标准化设计手段来扩大船厂智能制造应用范围和场景。形成船体零部件标准化、批量化设计原则和标准,达到降低船舶智能制造技术难度,最终实现船舶制造向连续型生产模式转变的目的。  相似文献   

7.
周然 《造船技术》2023,(3):52-59
以某国内大型风电平台上层建筑分段吊装为例,对新设计的一体式上层建筑分段进行吊装方案编制并借助有限元计算软件进行方案校核。在吊装计算中,主要从2个方面进行考虑:一是如何高质量地完成计算分析,保证计算符合实际情况,得到真实的结构响应;二是对吊装布置和加强方案进行分析,根据有限元分析结果为基地建造部门提出建议,保证吊装方案科学合理。给出一种新的有限元分析方法,并比较其与常规方法的加载方式。比较2种方法的计算结果,验证新方法可真实有效地模拟吊装的受力情况。分析结果可为造船企业今后提升海洋平台建造分段吊装工艺水平提供参考和借鉴。  相似文献   

8.
马誉贤 《船海工程》2012,41(3):128-130
结合企业计算机应用的实际,以及造船生产劳动强度大、劳动环境恶劣、船用配件和材料种类繁多等特点,介绍在造船工业中,将设计、制造、管理等集为一体纳入计算机综合管理的集成系统,目的在于寻求一种采用计算机技术挖掘企业内部潜力,提高工作效率、推进企业信息化、加快企业生产和管理现代化、提升企业综合竞争力的新途径。  相似文献   

9.
Associated with the rapid increase in the production of cultured marine shrimp has been large‐scale conversion of mangroves to shrimp ponds. Production in many regions has proved to be unsustainable, largely due to inappropriate construction methods, poor environmental conditions, overstocking, and disease. A number of shrimp ponds consequently are unproductive and lie idle. Accurate assessments of pond disuse are difficult to obtain; however, unofficial estimates have suggested that as many as 70% of ponds may be disused after a period in production. Pond construction, shrimp culture, and pond disuse lead to alterations to the physical and chemical properties of soil, hydrological conditions, and the flora and fauna composition of the pond area. The case for restoration, or rehabilitation to a sustainable use, is strong. Consideration must be given to the causes of production failure, the environmental conditions remaining following disuse, the needs and preferences of pond owners and coastal managers, and technical constraints.  相似文献   

10.
叉车技术的发展趋势   总被引:2,自引:0,他引:2  
现代叉车技术发展的主要趋势是,充分考虑舒适性、安全可靠性和可维护性,产品专业化、系列化、多样化,大量应用新技术,完善操控系统,重视节能和环保,全面提升产品的性能和品质.  相似文献   

11.
针对船舶航行安全的薄弱环节,在故障树分析船舶搁浅事故成因的基础上,运用贝叶斯网络对事件之间的多态性和逻辑性进行了研究。得到了事件的后验概率值,分析了导致事故发生的薄弱环节,推理得出最可能引起事故发生的事件组合,结果与统计资料一致,为提高船舶运营的安全和运营管理提供了科学依据。  相似文献   

12.
This paper aims to present and explain the work undertaken at the SSRC on the Safety of Bulk Carriers in extreme weather conditions over the past 3 years, to draw conclusions deriving there from, concerning key influencing design, operational and environmental parameters and to offer recommendations regarding the rule development process and on the way forward considering research, development and implementation to ship design and operation with the view to improving the safety of these ships cost-effectively. In severe storms, hatch covers of low freeboard vessels such as bulk carriers are the first-line of protection against flooding. Present methods of hatch covers design are still empirical because impact loads due to green seas and structural behaviour due to this type of loads have not been examined, hence not known accurately. The loading due to green seas is implicitly non-linear and, as model test results demonstrated, bulk carriers in extreme conditions are exposed to significant loads, which in some cases exceed current design standards. Since the consequences of hatch cover failure are potentially catastrophic, the risk of this happening should be quantified in probabilistic terms as required by modern safety standards. To this end, the paper aims to propose and implement a methodology for estimating probabilities of deck wetness and impact loads due to green seas as a function of key design and operational parameters.  相似文献   

13.
船舶发动机盖外板与内板之间常涂覆一层防震密封胶,但具体涂胶形态难以观测,常用机器视觉手段获取产品涂胶图片。针对涂胶区域分割和检测精度低,效率慢的问题,提出一种新的边缘提取算法获取涂胶区域。为了避免传统Canny边缘检测方法易受噪声干扰的缺点,采用具有保边特性的加权最小二乘法滤波器对图像滤波去燥,增加45°和135°两个方向计算图像梯度,利用改进后的Canny算法获取边缘,对获取到的边缘点用区域生长方式将涂胶区域提取出来,最后将提取到的涂胶区域与标准涂胶区域进行配准和减影,得到减影结果即为涂胶缺陷。试验仿真表明:本算法能够很好的提取到胶水区域,并且获取胶水缺陷。  相似文献   

14.
隔振器对舰船基座振动特性的影响   总被引:1,自引:1,他引:0  
为了研究隔振器类型及布置方式对舰船基座振动特性的影响,针对舰船设备普遍采用隔振器与基座相连的连接方式,首先分析了隔振器刚度、阻尼等参数对舰船基座激扰力特性的影响,并以某船舶发电机组为例,基于有限元方法讨论了隔振器类型及布置方式对舰船基座振动特性的影响。研究表明,一方面,设备向基座传递的激扰力与隔振器刚度、阻尼及设备—隔振器—基座系统固有频率等密切相关;另一方面,隔振器类型及布置方式对基座振动特性也有较大影响。当激励频率较低时,隔振器布置方式对基座振动特性的影响相对较小;而当激励频率较高时,隔振器布置方式对基座振动特性的影响则相对较大。  相似文献   

15.
人类工业化历史经历了从手工作业到流水线生产再到柔性制造3个发展阶段,其中,大规模流水线生产是标准化运用的巅峰,因为流水线生产对标准化的要求最高,其对产品的设计标准化、工艺标准化和生产标准化等都提出了严格要求.然而,伴随着中国工业化程度的进一步加深,市场竞争愈发激烈,同质化产品越来越多,为了进一步提高自身产品的竞争力,越...  相似文献   

16.
大型豪华邮轮结构设计的难点及对策分析   总被引:1,自引:1,他引:0  
简述了大型豪华邮轮的结构特点,介绍了大型豪华邮轮的特殊要求,指出了结构设计中存在的困难和问题,研究了解决困难的对策和方法,对于大型豪华邮轮的结构设计,关键在于特定结构设计水平的提升,薄板加工焊接变形的控制,振动和噪声的预防,结构细节的处理,结构与设施的协调等。  相似文献   

17.
李军 《船舶工程》2020,42(11):16-20
为使编制的计划具有良好的可执行性,利用虚拟仿真技术建模和优化,对编制的计划作出预测评估和可行性分析。通过Plant simulation仿真工具,参照车间实际布局,从车间层到单元设备,逐层次建模,根据设计输出BOM所确定的中间产品物量及工艺流向,结合场地资源、设备资源和劳动力资源等约束条件,把船厂生产信息完整的映射到仿真平台。通过仿真所得到的可视化分析结果,利用GA遗传算法优化仿真结果,评价计划编制的合理性和可执行,为计划编制提供基于可动态实时调整的参考方案。  相似文献   

18.
为适应天津港GIS系统建设需求,将传统的CAD数据转换为GIS格式的数据已经成为必需.而由于长期的绘图手段和绘图习惯,CAD数据存在着点、线不合规范,面不闭合,层与层内的图形混乱等现象,使CAD数据与GIS数据的结构存在很大差异,不能将CAD数据完整地向GIS数据迁移.在分析目前CAD数据到GIS数据迁移中存在问题的基础上,深入探讨天津港基础地形图数据转移为GIS数据的逻辑结构、分层设计和属性设计等解决方法.  相似文献   

19.
The objective of this article is to analyse the factors that affect port competitiveness from the perspective of the agents and companies that operate in one of the Mediterranean ports most active in container traffic: the Port of Algeciras Bay (PAB). It is essential to understand the perspective of the suppliers of port services, in order to apply the necessary judgment when formulating policies to strengthen the competitive position of a port. The model selected to meet the objective outlined is based on the 'extended diamond' of Porter. The universe for the study comprises all the institutions and companies involved in the containerization process in the Port of Algeciras Bay. Within this methodology, two procedures are utilised. First, from the quantitative perspective, a survey has been conducted to obtain responses to two groups of questions, one dealing with situation and the other with perceptions. Second, and from a qualitative perspective, several open interviews have been conducted to corroborate the responses obtained to the questionnaire. From the data obtained in the survey, a model has been estimated that minimises the sum of the residuals in absolute value, utilizing the L1 regression; this model enables the competitive advantages and disadvantages of the PAB, from the point of view of the port operators, to be determined by an analysis of residuals. This analysis demonstrates that the variables representing greater competitive advantages are associated with trans-shipment, and with the maritime accessibility of the Port to vessels, whereas those generating greater disadvantages are associated with rail transport (which, according to those surveyed, has resulted in the diversion of significant volumes of traffic to other Spanish or European ports with better communications, particularly Valencia, Barcelona and Gioia-Tauro, and with the state of competition in container trans-shipment activities.  相似文献   

20.
The objective of this article is to analyse the factors that affect port competitiveness from the perspective of the agents and companies that operate in one of the Mediterranean ports most active in container traffic: the Port of Algeciras Bay (PAB). It is essential to understand the perspective of the suppliers of port services, in order to apply the necessary judgment when formulating policies to strengthen the competitive position of a port. The model selected to meet the objective outlined is based on the ‘extended diamond’ of Porter. The universe for the study comprises all the institutions and companies involved in the containerization process in the Port of Algeciras Bay. Within this methodology, two procedures are utilised. First, from the quantitative perspective, a survey has been conducted to obtain responses to two groups of questions, one dealing with situation and the other with perceptions. Second, and from a qualitative perspective, several open interviews have been conducted to corroborate the responses obtained to the questionnaire. From the data obtained in the survey, a model has been estimated that minimises the sum of the residuals in absolute value, utilizing the L1 regression; this model enables the competitive advantages and disadvantages of the PAB, from the point of view of the port operators, to be determined by an analysis of residuals. This analysis demonstrates that the variables representing greater competitive advantages are associated with trans-shipment, and with the maritime accessibility of the Port to vessels, whereas those generating greater disadvantages are associated with rail transport (which, according to those surveyed, has resulted in the diversion of significant volumes of traffic to other Spanish or European ports with better communications, particularly Valencia, Barcelona and Gioia-Tauro, and with the state of competition in container trans-shipment activities.  相似文献   

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