首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
海事救助系统主要分为船舶自动识别系统、全球海上遇险与安全系统、船载航行数据记录仪、中国船舶报告系统、电子海图显示与信息系统等部分组成,对海上搜救和事故调查起着重要的促进作用。该文则主要基于我国海事救助通讯现状分析我国海事救助系统下属子系统,并根据系统提出需改进部分,希望以此作为提高海事工作的参考依据。  相似文献   

2.
综述电子海图导航系统的标准化历程和应用现状,从多维化、一体化、开放化、服务化以及移动化等维度分析电子海图导航系统的进化,介绍多维电子海图、船联网、S-100标准、E-Navigation、智能服务和移动导航APP等相关关键技术.结合智能船舶的发展趋势,分析环境感知、增强现实、VDES和自动驾驶等技术与电子海图导航系统相结合的应用前景.  相似文献   

3.
在海上台风预警搜救系统中,存在数据丢失现象,为了能够正确地、实时地显示船舶在电子海图上的当前位置,应用半P-集合,提出F-导航数据与F-匹配度概念,给出辨识F-导航数据的定理、F-导航数据的恢复定理、导航数据的稳态匹配度定理、导航数据在电子海图路径上的匹配准则,最后给出F-导航数据在电子海图上的路径匹配应用。  相似文献   

4.
海上救助工作中救助船舶的优选原则与方法   总被引:2,自引:0,他引:2  
船舶遇险后,正确选择求助船舶的方法是保证成功救助的关键。通过对海上船舶遇形及可能造成后果进行分类及分析,提出了海上救助船舶的择优造字以原则与方法,试图主管机关协调救助行动有所帮助。  相似文献   

5.
在海上台风预警搜救系统中,存在数据丢失现象,为了能够正确地、实时地显示船舶在电子海图上的当前位置,应用半P-集合,提出■-导航数据与■-匹配度概念,给出辨识■-导航数据的定理、■-导航数据的恢复定理、导航数据的稳态匹配度定理、导航数据在电子海图路径上的匹配准则,最后给出■-导航数据在电子海图上的路径匹配应用。  相似文献   

6.
刘厂  高峰 《应用科技》2010,37(6):50-55
基于GIS组件开发已经成为地理信息应用系统开发的主流,我国已经具备了生产国际标准电子海图数据的能力,但目前市场上还没有支持国际标准电子海图数据的GIS组件.在研究了电子海图国际标准和COM组件的基础上,分析了电子海图显示平台的组成结构,完成了显示平台组件的结构设计.在Visual C++ 6.0下利用ATL技术,实现了显示平台组件,验证了这种开发方法的可行性.  相似文献   

7.
基于电子海图的船舶动态监控系统设计与实现   总被引:9,自引:0,他引:9  
介绍了基于电子海图的船舶动态监控系统的结构、功能、特点及部分实现技术,系统综合运用高精度差分GPS定位技术,通话技术,数据处理技术,电子海图显示技术,CRACLE数据库管理技术,对在航船舶进行跟踪、监控和管理,实践表明,该系统能够有效地保障在航船舶在受限水域以及能见度不良情况下的航行安全。  相似文献   

8.
针对江苏预警报服务与渔船安全救助结合的难题,提出了一种电子海图综合信息系统系统的设计方案.该系统以电子海图为基础,通过CDMA、AIS、GPS/GPRS等通讯手段自动采集渔船的动静态信息,并能够在电子海图上将渔船分布信息与预警报产品相叠加,实时显示预警报海域的渔船情况,自动识别渔船风险并发送警报信息,最大限度地减少和避免渔船员伤亡和经济损失.  相似文献   

9.
为了使船舶航行更加安全,采用自动识别系统技术、网络电子海图技术、无线通信技术及数据库技术,利用监测的航标数据及AIS船舶数据,结合航标基础数据,在WEB-ECDIS航标助航信息管理平台上,整合其他航标助航信息,通过AIS电文6、8、12、14、21进行发布,以实现航标助航信息服务.  相似文献   

10.
电子海图系统中船舶避碰的神经网络方法的研究   总被引:3,自引:0,他引:3  
提出用神经网络方法来研究电子海图系统中的船舶避碰,使用神经网络型建立船舶会遇的碰撞危险性识别及最优避碰方案决策系统,利用电子海图技术在模拟海上环境的基础上,考虑船舶操纵特性及其海况影响,提出一种解决船舶避碰的新方法,取得了满意的效果。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号