Parameter identification of a compliant nonlinear SDOF system in random ocean waves by reverse MISO method

The determination of the drag and inertia coefficients, which enter into the wave force model given by Morison's equation, is particularly uncertain and difficult when a linear spectral model is used for ocean waves, and the structure is compliant and has nonlinear dynamic response. In this paper, a nonlinear System Identification method, called Reverse Multiple Inputs–Single Output (R–MISO) is applied to identify the hydrodynamic coefficients as well as the nonlinear stiffness parameter for a compliant single-degree-of-freedom system. Four different types of problems have been identified for use in various situations and the R–MISO has been applied to all of them. One of the problems requires iterative solution strategy to identify the parameters. The method has been found to be efficient in predicting the parameters with reasonable accuracy and has the potential for use in the laboratory experiments on compliant nonlinear offshore systems.     

A new type of Shipboard Meteorological Satellite Receiving-processing System

INTRODUCTIONTheSMSRPSisstalledontheshipnavigatingovertheseaandreceivessatellitecloudmapsatanytimetoprovidereliablereal-timedataofmeteorologyandocean.Itisanimportantequipmentforsafeguardofshipnavigation.Chinahasthousandsofoceanicships.Butalmostallships,withonlyveryfewexception,arenotstalledbySMSRPS.Thecausesareasfollows:1.Thetechniqueisverycomplicated.2.Thedevelopmentcostisveryhigh.3.Ifweintroduceforeignequipment,thecostistooexpensive.4.Foreignequipmentanditssoftwarearecompletelyclo…     

关于海域面积精确计算的若干问题探讨

海域面积精确计算是实现海洋功能区划的基础和关键之一。本文通过对江苏省海洋功能区划工作中误差的分析 ,并针对其产生原因 ,在地图投影的选择和坐标的变换、扫描精度的控制、配准精度的控制、图象的数字化和图形编辑等方面 ,提出了相应的优化处理方法 ,提高了海域面积计算的精度 ,将其中误差控制在估计值范围内 ,从而在实际工作中有一定的应用价值。     

Are invasive species most successful in habitats of low native species richness across European brackish water seas?

European brackish water seas (Baltic Sea, Black Sea and Sea of Azov, Caspian Sea) are subject to intense invasion of non-indigenous species (NIS). In these seas, salinity is the most important range limiting factor and native species seem to reach a minimum species richness at intermediate salinities. This trend, revealed by Remane in 1934 and later on confirmed by many other scientists, was compared to the salinity range of already established NIS in the European brackish water seas. It turned out that most NIS are well adapted to the salinities holding lowest native species richness, already in their native area, and that NIS richness maximum in brackish water seas occurs in the salinity intervals of native species richness minimum. A predictable pattern in the salinity range of NIS can be used as a tool in initial risk assessment of future invasions in brackish water seas, especially when mapping highly potential donor and recipient areas. A product of empty niches, suitable environmental conditions, and availability of proper vectors might be the most effective predictor for the invasibility of brackish water areas.     

用Matlab中的Neural Network Toolbox仿真赤道东太平洋SST的预报模型

基于ＮＣＥＰ／ＮＣＡＲ再分析资料和ＣＯＡＤＳ海洋资料中的全球月平均海平面气压场、８５０hPa纬向风场及海洋温度场，利用Ｍatlab中的Ｎeural Network Toolbox仿真环境和ＢＰ模型改进算法比较准确地仿真和反演出了南方涛动指数、赤道纬向风指数和滞后的赤道东太平洋海温之间的动力结构和预报模型。该模型具有很好的拟合精度和可行的预报效果。可在一定时效内预测赤道东太平洋月平均海温的变化趋势。由于所建系统是具有直接因果关系的预报模型，因此不仅可直接用于预测，而且可有效避免类拟非线性微分方程组在积分过程中由于对初值敏感性而可能产生的对预报结果的不确定性。     

Heavy metals in marine sediments of Taranto Gulf (Ionian Sea, Southern Italy)

Al, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Ti and Zn concentrations have been determined in surface sediment samples collected in the Taranto Gulf (Ionian Sea, Southern Italy) in order to evaluate their levels and spatial distribution in this important area of the Mediterranean Sea. For various metals, the geoaccumulation index has been calculated as a criterion to assess if their concentrations represent contamination levels or can be considered as background levels. The results show that metals concentrations in sediments can be considered near the background levels found in the Mediterranean Sea.Analytical results have been elaborated by using a Geographical Information System (GIS) software to show metals accumulation areas. Using multivariate statistical analysis, we evaluate the possibility to distinguish the sampling stations, in relation to their geographical position. Results have showed metals distribution in the Taranto Gulf is principally influenced by industrial and urban wastes, located mostly in the northern coastal area of the Ionian Sea. Rivers in the Basilicata region and prevailing anticlockwise marine currents are further factors influencing metal accumulation in sediments.     

红河断裂构造带在东南亚的延伸特征及其大地构造意义

根据地质、地貌及地球物理资料分析,探讨展布于云南边陲哀牢山两侧的北西向断裂组成的红河断裂构造带,在东南亚的延伸特征。提出在该延伸带两侧沉积建造、构造活动,地球物理场和大地构造发展上均有显著差异。并进一步探讨该断裂构造带在大地构造上的意义。     

GIS新引擎——“真图”数据解决方案

提出了一种基于移动测量系统技术的"真图"数据解决方案。一方面极大地丰富了GIS数据源,另一方面通过相应的真图影像数据管理软件及开发包扩展GIS功能,为各行业应用提供了地理信息数据解决方案。     

关于城市交通地理信息系统模型设计的思考与改进

GIS—T模型是建立城市交通地理信息系统的主体,本文对现有GIS—T模型进行了简单的分析与评价,并且为了增加政府与公众做出决策的正确性,提出了路径畅通可靠度模型、城市交通综合指数模型、交通出行指数模型三个数学模型,以达到量化城市交通与完善GIS—T模型的目的。     

北京市地理空间框架基准体系建设与应用

重点介绍了北京市地理空间框架基准体系的实现过程,包括空间坐标基准、高程基准、似大地水准面和全球卫星定位测绘服务系统建设。基准体系检测结果表明,北京市地理空间框架基准体系达到设计要求,在国内率先实现了测绘基准的现代化建设。