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1.
指出现有不定期航航次估 存在的问题。通过大量的统计调研,分析某航区出现大风的概率及其对不定期船航次产生的影响,验证不定期船一个航次遇k次大风而停泊的总天数的概率由。计算出不定期船航次每天净化收益的望期值,从而作出不定期船航次估算的风险概率决策。实例证明结果可靠,符合实际。  相似文献   

2.
航运企业经营管理DSS研究   总被引:1,自引:0,他引:1  
在系统地调查我国航运企业在经营管理决策中所 存在的问题基础上,针对航运企业经营决策,航运投资,船舶更新,不定期船,班轮经营,陆上产业等急待解决的问题,结合我国以企业管理的一般特点,对航运企业生产、技术,企划,经营活动在其决策过程中所存在的实际问题进行了系统地分析。  相似文献   

3.
张颖 《科技信息》2007,(32):64-65
无船承运人在国际贸易运输过程中具有双重身份,他既是海运提单的托运人,也是无船承运人提单的承运人.无船承运人的出现,沟通了货主和远洋公共承运人之间的信息,活跃了国际海运市场,在某种程度上降低了中小货主的运输成本.但是,另一方面由于无船承运人参与整个运输过程,阻断了货主与远洋公共承运人之间的法律联系,并有可能增加货主的风险.本文对无船承运人的涵义、特征、责任,以及目前我国对无船承运人宏观管理中存在的主要问题进行了初步探讨,并在此基础上,对发展我国"无船承运人"业务提出了若干建议.  相似文献   

4.
基于集合划分的航速可变不定期船舶调度模型   总被引:1,自引:0,他引:1  
基于不定期船多货物、多船舶、多挂靠港口和多航线的运营组织特征,综合考虑船速对航次时间、航次成本的非线性影响,提出了不定期船舶调度的非线性网络规划模型,用于解决航速可变的船舶选线与调度规划问题.针对模型的结构特点,设计了基于集合划分方法的两阶段求解算法.通过案例计算验证了模型和算法的效果.计算结果表明:考虑船速可变,制定的船舶调度方案能使营运收益提高10%~25%.新建立的模型能够对船舶运行计划、货载选择、包运货物运输组织方式和船速等进行统筹规划,制定详细的船舶运行时刻表,为不定期船舶调度实务提供决策支持.  相似文献   

5.
运用微观经济学的基本原理,分析不定期船即期航运市场的特征。通过运费率,运输技术,航次时间以及船舶航速之间关系的研究,推导出船舶边际收益等于边际成本的最大利润原则,从而作出不定期船即期航运市场的最佳效能分析。  相似文献   

6.
为了提高货主满意度的同时船公司能获得更好的经济效益,对不定期船调度与航速联合优化问题进行了研究,利用模糊时间窗刻画货主满意度,考虑自有船舶与租用船舶配置情况、航速等因素对船舶调度计划的影响,以航行成本、港口成本、时间成本、租船成本之和最小为目标,建立模糊时间窗下多船型不定期船调度与航速优化模型.提出一种变邻域遗传模拟退火算法进行求解:先将船型与货物匹配,再根据时间约束生成路径,最后采用邻域搜索策略提高求解质量.算例验证表明:船舶调度与航速联合优化可降低航行成本;注重货主的时间要求可提高其满意度.研究成果拓展了船舶调度及航速优化的相关理论,可为船公司优化不定期船调度及航速提供理论指导.  相似文献   

7.
为解决远洋测量船在海上缺少精度校准目标的问题,就光电经纬仪采用海上跟踪恒星的方式,从选星、引星和数据解算 3 个方面对远洋测量船上惯性导航设备提供的航向数据校准的相关技术进行了分析研究,并基于现有条件和技术提出一种结合正弦波拟合方式对船摇数据进行滤波和外推的算法。该算法通过对船摇数据进行抛物线差值细分,再经过最小二乘法获得正弦曲线拟合参数。在随“远望”号测量船出海期间对此方法进行了验证,实验结果证明该方法可有效提高船摇隔离度、增强空间目标跟踪能力,且在解算航向误差时具有较高的准确性和一致性。  相似文献   

8.
船舶机舱监测报警系统的设计   总被引:1,自引:1,他引:0  
针对我国现有远洋船舶的实际情况,为中远总公司船舶“丰台山”号研制了船舶机船监测报警系统,进行了硬件设计,软件设计并解决了与该船原系统之间的切换,为旧船机舱报警系统的改造和更新换代,开辟了一条新途径。  相似文献   

9.
今年9月,《人民日报》曾报道了我国家海洋局向阳红16号远洋科学考察船圆满结束太平洋锰结核综合调查,胜利返回上海的消息,这是我国向开发海洋资源进军的又一项重大措施。  相似文献   

10.
界定了GDSS信息收集的内涵;构建了信息流图描述群体决策过程决策成员与决策环境、决策任务以及决策成员之间的信息流动途径;最后,针对GDSS信息收集流,利用多智能主体的问题合作解技术,建立基于Multi-agents的信息收集模型。  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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