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1.
为研究并构建一类考虑相邻跑道干扰的进离场航班排序多目标优化模型,该模型综合考虑了跑道运行模式、管制员工作负荷、飞机类型、航空器安全间隔等多种因素,以航班延误最少、跑道利用率最高为目标.根据该模型特征,设计出带精英策略的快速非支配排序遗传算法(NSGA-Ⅱ)求解该非线性问题,揭示了不同目标下Pareto最优解之间的关系,将航班分配给不同跑道,确定其进离场时间.最后,本文以某机场的航班进离场为例,给出了优化方案,并将改进后优化模型与传统模型进行了对比,同时,对模型的参数进行了灵敏度分析,从而验证了该模型的正确性.  相似文献   

2.
为缓解大面积、长时间的离场航班延误现状,研究了多目标离场航班优化排序问题,考虑连续航班对离场航班影响,建立了具有多个目标函数的混合整数规划模型,并基于多目标优化问题的Pareto最优解概念,设计了一种带精英策略的非支配排序遗传算法(NSGA-Ⅱ)求解模型.选取上海浦东机场3 h内离场航班进行仿真验证,并将仿真结果与其他算法优化方案比较,与FCFS策略相比,航班总延误降低了20. 1%,延误架次减少了20.较单一目标优化,该算法具有保持多个目标函数优异性的特点,且115架航班优化时间仅为302 s,能够较好的满足实际运行效率需求.所提方法能够有效解决离场航班多目标优化排序问题.  相似文献   

3.
当终端区比较拥挤的时候,就需要对到达流航班着陆顺序进行调整,以有效缓解终端区的压力、缩短队列完成时间、提高飞行的安全性.飞机排序问题(ASP)属于NP-hard问题,通过将飞机排序问题表示成单机调度问题,设计了求解ASP的蚁群算法,以减少飞机队列总的完成时间最小为优化目标.通过与FCFS调度方法进行对比来验证基于蚁群算法的单机调度问题在单跑道机场终端区到达流排序中具有更好的适用性.  相似文献   

4.
近年来,中国民航持续高速发展,预计“十四五”末期中国民航运输机场数量将达到270个以上,逐步实现运输机场网络化覆盖。然而,由于机场之间空间分布过于密集而形成的机场集群式效应,造成邻近空域之间存在着复杂的耦合作用关系,若不能在空间和时间上对机场群内各资源进行充分解耦,则难以提升整体运行安全和效率。当前运行优化技术主要侧重于各自局部单一资源的优化,并没有统筹考虑内部跨区域的约束条件以及跨业务的运行环境,因此仅能得到局部最优化管制策略。为解决机场群全局集中式运行协同规划的实际需求,对集成进离场与场面运行(integrated arrival and departure and surface operations, IADS)技术展开综述。首先,从进场、离场和场面局部运行优化技术出发,分析中外研究近况并指明现存问题及研究局限;其次,创新性地对集成进离场与场面运行概念与技术总-分结构进行阐述,系统性说明IADS内在成分和逻辑关联;最后,分别从宏-微观尺度详细描述IADS所涉及的联合进场-离场调度排序问题、机场场面运行管理问题、进-离场航线选择问题以及基于时间的过点时序管控问题的算法框架和模型,...  相似文献   

5.
针对大型枢纽机场日益严重的场面拥堵及由此导致的航班延误问题,推出率控制策略可利用机位等待代替滑行道及跑道口等待,控制场面离场航班的滑行数量,缓解场面拥挤.基于推出率控制策略同时结合场面滑行路径优化,提出了基于航班离场成本的离场航空器滑行策略.首先,构建了基于推出率控制策略的航班离场成本计算模型;然后,提出离场航空器滑行策略优化方法;最后,以航班离场成本最小为目标,采用遗传算法开展算例仿真,并选取三种策略进行对比分析.结果表明:基于航班离场成本的滑行策略不仅能减少离场航班的总滑行时间,提高场面运行效率,还能减少燃油消耗和气体排放量,具有一定的环保性.  相似文献   

6.
终端区飞机排序的人工蜂群算法   总被引:3,自引:0,他引:3  
摘 要:为缓解终端区空中交通压力,研究了人工蜂群算法在终端区飞机降落排序中的应用。建立以航班总延误时间最小为目标函数的规划模型,运用人工蜂群算法,对着陆飞机排序问题进行了仿真计算,并与先到先服务算法、模拟退火算法、蚁群算法进行了对比研究。仿真结果表明:在双跑道模型下,人工蜂群算法比先到先服务算法,延误减少了48%。与模拟退火算法和蚁群算法相比,人工蜂群算法求解的结果最优且用时最少。说明应用人工蜂群算法求解终端区飞机排序问题是可行的。  相似文献   

7.
针对育种算法虽然能解决手机键盘字母排序优化问题,但存在搜索时间长,收敛速度慢的问题,提出手机不适度模型.该模型引入夭折机制和进化变异系数等改进方法,对育种算法进行改进,很好地解决了这些问题,并将之应用于手机键盘字母优化排序中,极大地提高了中文输入的效率.仿真实验表明,改善算法具有更快的计算速度和更优的收敛值,并能很好地求解手机键盘字母优化排序问题,证明了改进算法的先进性.  相似文献   

8.
基于多子群海洋捕食者算法提出在探索与开发阶段动态地采用新系数,并针对追随者子群更新算法进行优化.通过自适应调整领导者子群、追随者子群和衔尾者子群的种群规模,在全局探索和局部开发需求之间取得平衡.采用多种算法进行对比试验,结果表明该策略在优化问题上取得了改进和成效,适用性更广,为后续的研究和应用提供了重要的参考与借鉴.  相似文献   

9.
面向实际运行的战略航班时刻优化技术   总被引:1,自引:0,他引:1  
为了对航班时刻进行科学合理的配置,以机位、跑道和走廊口构成的系统为研究对象,考虑航班在系统内的实际运行情况,通过滑行时间和飞行时间在各关键资源节点之间建立连接.以满足关键资源节点的容流匹配为前提,建立了面向实际运行的航班时刻优化模型.以5 min为步长的滑动时间窗,设计了面向精确解的高效最优化算法并使用MATLAB工具箱编程求解.对浦东机场班期时刻表进行实例优化,并应用AirTop软件进行仿真验证.研究结果表明,优化后平均离场延误降低了3.2 min,高峰离场延误降低了23 min,放行正常率提高了11.04%,证明了该模型和算法的有效性,可以为大型机场缓解延误、保障运行效率提供航班时刻配置方案的理论支持.  相似文献   

10.
基于现有排序算法的缺陷,提出了对大型数据库排序算法智能化的改进方案:定义了“有序度”函数描述待排数据的特点,并自适应地选择相应排序算法,极大地提高了对大量数据进行排序的效率.提出的新算法在一般情况下与“快速排序”效果相当;但在较差情况(待排数据基本上有序)下,效率则显著提高,是一种极具实用价值的算法.  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.
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   

18.
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   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
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