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1.
为了研究船舶长度和速度对船舶领域的影响,基于AIS数据,建立受限水域内船舶动态领域模型。首先选取目标船舶,统计每一时刻他船到目标船的距离和相对方位,获得单船船位分布图,然后根据船舶长度和速度对目标船进行分类,对同一类型单船船位分布图进行叠加,采用数理统计方法确定船舶领域的边界,最终建立受限水域船舶动态领域模型。以舟山港螺头水道为例,共挖掘出15种不同类型的船舶动态领域模型。结果表明:船舶领域的长度随着船长,船速的增加而增加,当船舶长度相等时,船舶速度越大,船舶领域增加的幅度越大;船舶领域长度与船舶长度的比值并非为定值,而是随着船长,船速的增加而递减,船速越大,递减的幅度越大。  相似文献   

2.
为了保证船舶航行操纵中使用电子海图显示与信息系统(ECDIS)时,能更精确地标绘出本船与它船构成的危险程度.首先分析了航海雷达和卫星定位导航数据的原理和作用,然后再根据雷达、北斗和GPS卫星导航数据,在操纵船舶避碰时能恰当地选用更高精度的设备.船舶是根据未来船位进行预估危险然后采取行动避碰,卡尔曼滤波方式可预估出未来时刻的船位,通过Matlab仿真得出卡尔曼预估的船位基本上与实际船位误差符合航海要求,因此可用卡尔曼滤波方式进行预判两船是否存在危险.  相似文献   

3.
Kalman滤波技术在船舶动力定位技术中的应用   总被引:2,自引:0,他引:2  
提出了Kalman滤波技术在船舶动力定位中的应用方法,并以300m救生母船为实例分析了如何根据船舶的运动方程船舶运动的数学模型,并设计了Kalman滤波器,通过计算机仿真试验说明该滤波器能够较好地估计出船舶的真实船位和艏向。  相似文献   

4.
随着现代化科技的发展,AIS被船舶广为应用,在AIS基础上的AIS监控系统越来越多的被应用到引航监控、海事监管、代理和船舶公司调度等各个领域.在船舶安全和提高工作效率等方面发挥着重要的作用,也是引航实现"智能引航"必不可少的技术.引航中心AIS监控系统是通过对船舶动态监控利用安全预警、安全信息收发、轨迹回放、视频监控等功能实现对引航船舶安全监控,从而提高和完善其对引航安全的作用和效率,减少引航违章、违法和事故发生.  相似文献   

5.
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   

6.
根据当前船舶自动化和嵌入式系统的发展趋势,以ARM7处理器和μC/OS-Ⅱ操作系统设计CAN总线的节点,提出一种基于嵌入式系统和CAN总线的船舶机舱监控系统.进行船舶机舱监控系统的网络结构设计,给出嵌入武CAN总线节点和PC-CAN适配卡的设计方法.设计内容作为模拟机舱监控系统的重要组成部分得到了实际应用.  相似文献   

7.
为了准确识别异常航行轨迹的船舶,以船舶AIS信息为数据源,利用统计学中曲线拟合的最小二乘法对训练集船舶轨迹点进行拟合,得到船舶典型航行轨迹的数学表达模型,以此作为标准,通过计算监控船舶轨迹点与典型轨迹间的距离是否大于典型轨迹95%置信区间的范围,从而对轨迹异常的船舶进行识别.实验结果表明,该方法可以有效地识别轨迹异常船舶.将该方法运用到监控系统中可以提高海上交通监控效率.  相似文献   

8.
鉴于船舶结构的复杂性和环境的特殊性,船舶一旦发生火灾,很难得到及时有效的消防外援,其危害程度远远大于陆地上火灾,船舶火灾智能监控系统肩负着探测火灾隐患、保障人们生命和财产安全的重任,该文简要介绍了船舶火灾的成因及特点,对船舶火灾智能监控系统的研究现状及发展趋势进行了讨论,研制超早期、人性化的智能火灾防控系统对船舶安全具有重大意义。  相似文献   

9.
船舶自动识别系统(AIS)的出现极大地提高了海事管理机构的工作效率,保障了船舶的海上运输安全。但受限于船舶自动识别系统的工作半径,只有海岸线附近区域的船舶可以得到有效的监管调度。卫星AIS系统可有效弥补岸基AIS的弱点,AIS卫星可以在海事交通管理领域提供全天候、大范围的监控服务,实现对船舶实时动态的多要素、全方位监测。该文针对我国AIS卫星星座方案进行了研究,提出了我国AIS卫星发展路线的建议和AIS卫星分步组网的思路,并分析了其效能,为将来我国AIS卫星计划的实施提供了借鉴。  相似文献   

10.
通过对国内外动态质量管理系统现状进行分析,介绍了沥青混合料动态质量监控系统的特点和作用,分析了沥青混合料动态质量监控系统在工程应用中产生的经济和社会效益,通过无限网络传输,实现对沥青混合料的实时动态监控,以达到控制沥青路面质量的目的。通过实际工程应用,动态监控管理系统在沥青路面质量管理体系中的重要性和优越性得到了充分体现。  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 Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
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   

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