航班超售与舱位控制综合优化

舱位控制是航空收益管理的核心问题。运用动态规划方法,以收益最大化为目标函数,建立了考虑超售策略下的航班动态舱位分配控制模型,通过对模型的性质分析,证明了模型存在最优解。在乘客到达服从一定分布下,选取不同参数对模型进行分析,求解得到总超售数量及每一个舱位等级的预订限制。算例结果表明:航班乘客到达率对于总超售数量具有显著影响,控制最优超售数量可减少拒载现象的发生,有效的超售策略对航空公司提高经济效益和信誉具有重要的作用。     

基于航线网络的定价、超售与舱位控制策略研究

在单航段及多航段机票定价、超售与舱位控制模型基础上,将航线网络拆分为单航段与多航段组合形式,利用重叠航段旅客流量一定的特点,建立各航班机票销量间联系,将单航段和多航段模型有机结合,实现航线网络的机票定价、超售与舱位控制.针对两种简单的组合形式进行了推导和讨论,证明了控制策略的可行性,并建立对应管理模型,实现了航线网络定价、超售与舱位分配同步控制.     

团队与散客一体化舱位控制方法

团队控制问题对于亚洲航空市场,尤其是东南亚市场非常重要。在目前航空公司收益管理研究中,缺乏团队旅客的舱位控制问题研究。团队与散客的舱位控制是相互影响而不能割裂的,应将团队与散客的舱位控制问题综合起来研究。设计了一个数学模型,确定团队与散客的座位分配。由于模型是一个非线性模型,缺乏合适的求解算法。设计了一个分枝搜索算法。通过实例证明算法有效,研究结果可以提高航空公司收益。     

基于风险规避的航班舱位分配控制研究

本文从风险规避的角度研究航班舱位分配控制问题,基于风险规避的舱位分配控制研究能更好地说明未来收益的不确定性。本文采用的风险度量方法是引入期望收益的风险规避系数,表示收益的变化情况,分别建立单航段与多航段舱位分配控制模型。通过仿真分析,得到不同风险规避系数下单航段与多航段模型的舱位分配数量、期望收益及收益标准差,并通过风险规避系数的变化来分析对期望收益及不同舱位等级的座位分配所产生的影响,比较了单航段与多航段模型的求解结果,其结论证明了本文模型的有效性和创新性。     

航班计划的优化设计研究

以航空公司的正常营运和最大收益为目标,结合统计数据和目标要求,建立航班计划动态规划模型,采用贪婪算法对其进行求解,得到航空公司的航班计划、飞机数量的规划,从而为航空公司编制和优化航班计划提供一定的理论依据和方法支持.以某航空公司特定机型的航班计划数据进行实证,验证了该模型和算法的可行性.     

基于作业成本法的航空公司成本费用核算的优化分析

随着航空公司内外部竞争环境的日趋激烈,降低运营成本成为航空公司不可回避的主要课题。成本核算作为成本管理工作的重要组成部分,是企业开展成本决策和经营决策的一种有效方法。本文对当前航空公司成本核算方法的现状、特征分析基础上,围绕存在的问题,基于作业成本法从旅客、航班、航线、网络、机型等五大方面进行作业成本核算分析,从而为航空公司成本管理提供了一条有益的思路。     

考虑碳排放和班轮联盟合作的航线网络优化模型

【目的】考虑到碳税的征收和班轮联盟运营成为主流，对该趋势下航线网络设计问题进行研究。【方法】采用合作博弈和逆优化理论，构建混合整数规划模型。该模型基于班轮联盟承运人之间的舱位交易活动，同步决策班轮航线网络设计方案、船队设计方案、航速方案、货物运输方案以及各承运人之间的舱位交易价格，该价格可确保各承运人按联盟整体收益最大的货物运输方案运营时，都能获得自身最大收益，从而确保了联盟合作的达成。采用遗传算法框架，设计模型的求解算法。【结果】基于亚欧航线实际运营数据，设置不同运价和碳税费率的案例，进行了灵敏度分析，结果显示不同情境下的航线网络方案中，碳税支出和联盟合作方案有所不同。【结论】运价对联盟网络结构和收益分配有明显影响：随着运价的提升，网络结构复杂性增强，市场份额高的承运人投资收益率更高；征收碳税明显改变了船舶运营策略：随着碳税费率的升高，船舶短途运输航程明显增加，承运人倾向于选择增加船舶数量，降低航速运营。     

基于动态博弈的补贴模式对机场群航线网络结构的影响研究

为探讨不同补贴模式对机场群航线网络结构的影响，本文构建了关于机场、航空公司和乘客之间的动态博弈模型，通过逆向归纳法得到了纳什均衡条件. 研究结果发现：（1）不同的补贴模式对多机场航线网络结构产生重要影响，低补贴模式促使机场群倾向于形成点对点航线网络结构，反之，在高补贴模式下机场群易于形成枢纽辐射航线网络； （2）在较低的空铁联运总运营成本环境下，补贴竞争使得航空公司倾向于选择系统内的大型机场作为枢纽机场；反之，如果空铁联运总运营成本相对较高，补贴竞争使得航空公司倾向于选择小机场作为枢纽节点； （3）随航班固定成本和空铁联运总运营成本的增大，大型机场作为枢纽节点的概率逐渐减少，而小机场被选为枢纽节点的概率将逐渐增大. 随着机场群内大型机场腹地服务人口比例的增大，航空公司选择点对点航线网络的概率在减小. 研究结论能够为民航管理部门科学制定和应用航线补贴政策提供决策依据.     

新冠疫情和双碳战略背景下班轮运输多目标优化

针对新冠疫情与"双碳战略"背景下的航线配船和货物分配问题,为满足班轮公司对船队运输效率、经济效益、服务质量和环保效益平衡发展的要求,以船队平均舱位利用率和营运利润最大以及货物时间价值损失与单箱碳排放量最小为目标,建立班轮航线配船与货物分配多目标优化模型.根据子问题间的内在联系,将模型分解为双层模型,上层采用混合整数非线...     

多航段舱位控制与定价策略

针对航空运输中的多航段航线舱位控制及动态定价策略问题,提出统一分析模型。采用最大凹向包络理论从给定的价格集合中确定出最优价格子集,再利用连续控制系统动态规划理论,建立哈密尔顿-雅克比控制方程并求解,并对求解算法进行稳定性分析。最后,进行了算例验证分析。研究结果表明:采用本文模型所得到的收益明显大于最低价和最高价策略。同时,分析了最优价格策略的售票特性,可供航空公司作参考。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

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.     

Jane Eyre——A Feminist In The 19th Century

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-