大型自主水下机器人全局静态与局部动态融合路径规划方法

针对大型自主水下机器人在做全局路径规划时面临环境建模复杂,算法求解能力弱以及面对局部动态障碍时自主性低,避障路径规划困难等问题,采用极坐标表示形成路径同心圆,在严格机动性约束下提出基于改进粒子群算法和速度障碍法的全局静态与局部动态相融合的路径规划方法。在极坐标表示的环境模型中,在全局静态规划中引入最优粒子"变异"过程提升算法求解能力;在局部动态规划中利用速度障碍法求解局部碰撞范围和安全路径区域以保证避障路径最优。实验结果表明,与传统粒子群和遗传算法相比,改进方法在全局静态规划中路径更短、求解能力更强,局部动态规划能够得到出最优避障路径。     

基于遗传算法规划路径的船舶避碰系统

为了更好地解决船舶避碰路径规划问题,寻找到船舶运动的最优最短的避碰路径,提出了遗传算法规划路径的船舶避碰系统,首先在遗传算法的选择、交叉和变异阶段,利用粒子群算法引入强化变异、改进交叉对象、变异淘汰机制,从而对遗传算法进行自我调整,避免遗传算法陷入局部最优,然后,将寻优得到的最优个体的位置与速度进行解码,得到最优的船舶避碰规划路径,最后进行了仿真实验。实验结果表明,本文算法不仅能够得到最优的船舶运动避碰路径,安全性高,而且整个求解所需时间最少,具有明显的优势,对于船舶运动避碰路径规划问题求解具有较好的可行性。     

改进遗传算法的舰船无线网络路由算法

针对原有舰船无线网络路由算法在使用后造成无线网络耗能较大的问题,引用改进遗传算法,设计基于改进遗传算法的舰船无线网络路由算法。设定舰船网络模型,获取网络中的链路重叠与干扰情况,计算无线网络信道分配数值。以上述计算结果为基础,引用改进遗传算法,设定无线网络的运行空间,根据遗传算法中的染色体计算技术,获取路由路径与数量的最优解。构建算法测试环节,通过与原有算法对比可知,此算法在使用后舰船无线网络的耗能低于原有算法。     

移动网络海上应急物流路径规划算法

传统算法缺乏海上应急物流路径规划网络数据库的构建,导致在对物资配送时时间过长,为此设计一种移动网络的海上应急物流路径规划算法。应用航行条件的属性信息,以矩阵形式构建海上应急物流路径规划网络数据库,根据数据库内信息确定海上路径可通行的难易程度,并对海上应急路径当量长度计算,寻求到最短配送路径进行静态路径规划,考虑船舶行驶中航行环境会发生变化,提出动态规划流程,完成海上应急物流路径的规划。实验中对多个物资点配送,结果表明此次设计的移动网络的海上应急物流路径规划算法的物资配送时间比传统算法的物资配送时间短。     

基于大数据与人工智能的舰船避碰路径优化调度算法

舰船航行路径中存在许多障碍物,当前舰船避碰路径优化调度算法存在障碍物识别正确率低、规划路径长,不仅无法获得最优的舰船航行路径,而且不能保证舰船航行的安全,为了获得最优的舰船航行路径,设计了基于大数据与人工智能的舰船避碰路径优化调度算法。首先分析当前舰船避碰路径优化调度算法的工作原理,找到弊端,然后引入大数据分析方法建立舰船避碰路径优化的数学模型,实现障碍物识别,并采用人工智能技术——遗传算法找到最优的舰船避碰路径,最后进行舰船避碰路径优化调度算法性能的仿真测试,结果表明,本文方法可以更快找到最优的舰船避碰路径,舰船避碰路径更短,不仅减少了舰船航行的时间和成本,而且可以准确识别各种舰船障碍物,具有显著的优越性。     

船舶自动航行中的多目标遗传算法应用

船舶自动航行是未来航海领域重要的关键技术,算法通过对船舶航行目标及安全水域的分析,自动的寻找船舶航行最佳路径,属于路径规划研究一类。标准遗传算法通过对遗传物质基因的继承和映射,来寻找自然进化过程中的最优解,也是解决路径规划类问题的重要方法,但是其最优解往往会陷入局部最优,需要进行优化。本文研究海上自动航行中的路径匹配模型,利用多目标遗传算法给出船舶路径规划图解决方法,并对算法进行仿真。     

舰船信息网络物流配送最优路径选取方法研究

利用基于神经网络或基于遗传算法等传统方法进行舰船信息网络中物流配送最优路径选取,选取质量较差,使得物流配送时间长,导致运输成本过高,降低了客户满意度。针对上述问题,提出一种基于Dijkstra算法的物流配送最优路径选取方法。该方法主要分为两步:对Dijkstra算法选取最优物流配送路径原理进行分析;在该原理基础上构建物流配送最优路径选取模型,包括问题描述、求加权矩阵、建立距离矩阵、确立需求量与配送距离之间的线性关系、构建Dijkstra算法模型等流程。结果表明:按照本方法选取出的最优路径进行物流配送,平均时间为55.69 h,按照基于神经网络或基于遗传算法等传统方法选取出的最优路径进行物流配送,平均时间为58.62 h和62.42 h。前者与后两者对比,配送时间大大缩短,由此证明本方法选取质量更好,能大大缩短物流配送时间,降低运输成本,提高客户满意度。     

结合免疫算法的船舶运输路径优化方法研究

为选取出港口船舶运输的最优路径,相关研究者将近几年兴起的智能算法,如禁忌搜索算法、遗传算法应用其中,但是这些算法均视最短路径为最佳路径,未从多个角度进行选取,导致选取出的路径虽然最短,但安全性较低、成本相对较高,整体运输路线质量不高。针对上述问题,研究一种基于免疫算法的船舶运输路径优化方法。该方法先需要对船舶运输路径优化问题进行描述,从多个角度进行约束,后利用免疫算法求取路径优化问题的最优解,完成最优路径搜索。结果表明,与基于禁忌搜索算法、遗传算法的港口船舶运输路径优化方法相比,本算法运行下,选取出的路径距离虽然并不是最短的,但是在时间、安全性以及成本方面均最佳,因此通过综合评估得出本方法选出的运输路径最优,证明了本方法的性能。     

基于改进人工蜂群进化算法的移动机器人路径规划与仿真分析

针对经典人工蜂群算法在机器人路径规划中易于陷入局部极值,且寻优过程收敛速度较慢等问题,提出了一种基于约束优化的改进人工蜂群算法.通过设计变异算子来增大极值在陷入局部最优时的跳出概率,提高机器人路径规划的收敛能力.在机器人路径规划上,对文中方法、遗传算法、A*算法以及经典人工蜂群算法进行性能评估.实验结果表明,文中方法能有效避免路径规划中的局部极值,减少机器人路径规划时间损耗,提高了路径规划效率.     

基于云计算技术的舰船通信网络路由算法研究

利用单一路由算法进行舰船通信网络信息传递时,存在信息传递效率低的情况。针对上述问题,提出一种基于云计算技术的舰船通信网络路由算法。该算法是一种由蚁群算法和遗传算法结合在一起的混合算法。首先利用蚁群算法搜索出所有能够实现信息传递的路径,然后利用遗传算法减少计算量,在所有路径中快速选出最佳路径,以实现信息的快速传递。结果表明:利用混合算法找出来的最佳路径进行信息传递比利用其余2种单一算法(蚁群算法和遗传算法)找出来的最佳路径进行信息传递,时间耗费分别减少了2 s和4 s,由此可知信息传递效率有了很大提高,说明了该混合算法的有效性。     

33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

Catalyzing Coastal Management in Kenya and Zanzibar: Building Capacity and Commitment

Site-based projects were initiated in Chawka Bay-Paje, Zanzibar, and Nyali-Bamburi-Shanzu, Kenya, to demonstrate the benefits of an integrated coastal management (ICM) approach for addressing coastal issues such as tourism development and enhancement of resource-dependent village economies in eastern Africa. A two-year, multidonor project used three primary strategies to make rapid, but sustainable, progress toward ICM. These included using interagency government teams for ICM planning, adopting an internationally recognized framework for ICM as a project ''road map,'' and explicitly incorporating capacity-building strategies into all aspects of the project. Within two years, integrated ICM action strategies, prepared through participatory processes, were being implemented at both sites, and both teams were working to expand the scale and scope of ICM in their nation. More importantly, the project helped create committed, capable, interagency groups that continue to work together to address urgent ICM issues.     

舰艇反鱼雷技术

对目前舰艇反鱼雷技术中的非杀伤、软杀伤和硬杀伤等比较先进的手段进行了阐述,并在此基础上分析研究了舰艇反鱼雷技术的发展趋势。     

A simplified method for reliability- and integrity-based design of engineering systems and its application to offshore mooring systems

This paper presents a simplified method for the reliability- and the integrity-based optimal design of engineering systems and its application to offshore mooring systems. The design of structural systems is transitioning from the conventional methods, which are based on factors of safety, to more advanced methods, which require calculation of the failure probability of the designed system for each project. Using factors of safety to account for the uncertainties in the capacity (strength) or demands can lead to systems with different reliabilities. This is because the number and arrangement of components in each system and the correlation of their responses could be different, which could affect the system reliability. The generic factors of safety that are specified at the component level do not account for such differences. Still, using factors of safety, as a measure of system safety, is preferred by many engineers because of the simplicity in their application. The aim of this paper is to provide a simplified method for design of engineering systems that directly involves the system annual failure probability as a measure of system safety, concerning system strength limit state. In this method, using results of conventional deterministic analysis, the optimality factors for an integrity-based optimal design are used instead of generic safety factors to assure the system safety. The optimality factors, which estimate the necessary change in average component capacities, are computed especially for each component and a target system annual probability of system failure using regression models that estimate the effect of short and long term extreme events on structural response. Because in practice, it is convenient to use the return period as a measure to quantify the likelihood of extreme events, the regression model in this paper is a relationship between the component demands and the annual probability density function corresponding to every return period. This method accounts for the uncertainties in the environmental loads and structural capacities, and identifies the target mean capacity of each component for maximizing its integrity and meeting the reliability requirement. In addition, because various failure modes in a structural system can lead to different consequences (including damage costs), a method is introduced to compute optimality factors for designated failure modes. By calculating the probability of system failure, this method can be used for risk-based decision-making that considers the failure costs and consequences. The proposed method can also be used on existing structures to identify the riskiest components as part of inspection and improvement planning. The proposed method is discussed and illustrated considering offshore mooring systems. However, the method is general and applicable also to other engineering systems. In the case study of this paper, the method is first used to quantify the reliability of a mooring system, then this design is revised to meet the DNV recommended annual probability of failure and for maximizing system integrity as well as for a designated failure mode in which the anchor chains are the first components to fail in the system.     

Community-Based Management for Sustainable Fisheries Resources in Phang-nga Bay,Thailand

Fishing communities, the Government of Thailand Department of Fisheries, local nongovermnental organizations, universities, the Food and Agriculture Organization of the United Nations (FAO), and FAO's Bay of Bengal Program have undertaken a partnership in management of Phang-nga Bay's coastal resources. It is the first project of its kind in Thailand, and although still in the early stages, offers insights that may contribute to our knowledge of how we can improve our management of coastal resources, including the importance of (1) building relationships within the governance process; (2) combining education, enforcement, and economic incentives to achieve compliance; (3) implementing solutions early; and (4) government support of community-based decisions. These insights reinforce trends emerging in other coastal management projects in the Asian region.     

含裂纹钢板复合材料修补强度和刚度数值分析

用ANSYS有限元分析软件对复合材料补片修复含边裂纹和中心裂纹钢板的强度和刚度进行了数值分析.引入相对刚度的概念,研究了钻有止裂孔裂纹的长度对损伤钢板相对刚度的影响,分析了损伤钢板刚度复合材料贴片修补效果;引入屈服载荷提高率的概念,分析了损伤钢板强度的修复效果.     

混凝土道路、堆场面层裂缝的产生与防治

从混凝土道路、堆场的各个结构层分析裂缝产生的原因,并针对性地说明预防措施,阐述裂缝维修方法。     

单相PWM整流器的建模与仿真分析

文章详细分析了单相VSR型PWM整流器的整流原理,建立了电流内环,电压外环的单相VSR型PWM整流控制器的数学模型和逻辑框图。在MATLAB／Simulink软件环境中进行了仿真,分析了模型的可行性。