具有相依变量成批到达排队系统等待时间的注记

研究了成批到达排队系统G(X)/G/1的基本变量具有相依关系时,等待时间的随机比较性质.证明了当到达批量与到达间隔的相依关系越强时,相应的等待时间越短;当服务时间和到达间隔的相依关系越强时,相应的等待时间越短.同时探讨了基本变量相依时成批到达排队系统的等待时间的界.     

有一般重试时间的Geo[X]/G/1重试排队系统

研究了重试时间是一般分布的批量到达的离散时间的Geo[X]/G/1重试排队系统.假定一旦顾客发现服务台忙就依先到先服务规则进入重试区域,并且只允许重试区域队首顾客请求重试服务.计算出稳态时系统和重试区域队长以及系统的其他各种指标.证明了所研究的离散时间重试排队系统可以逼近连续的具有一般重试时间的M[X]/G/1重试排队系统.     

具有二次多选择服务的M/G/1可修重试排队系统

研究了一个具有二次多选择服务和不可靠服务台的M/G/1 重试排队系统.所有到达系统的顾客都需要接受首次主要服务,而只有部分顾客选择接受由同一服务台提供的二次服务.假设两个服务阶段的服务时间和服务台维修时间均服从一般分布,应用补充变量法,得到了各种稳态排队指标和可靠性指标.     

预拌混凝土泵送施工系统的排队仿真与配置优化

基于排队理论研究预拌混凝土泵送施工系统的综合性能与配置优化.运用仿真工具建立混凝土泵送施工系统排队仿真模型,探讨混凝土泵车数量变化对系统综合性能的影响规律,发现随着泵车数量的增大,系统性能逐渐变好,泵车繁忙率降低,排队队长和排队时间降低,可服务的混凝土运输车数量增多,且存在一个最优泵车数量值.通过构建混凝土泵送系统最优配置模型,探讨泵车数量、泵车效率、混凝土运输车间隔时间之间的关系,指出提高混凝土泵送施工系统性能的措施.该排队系统仿真模型与实验结果对施工管理具有一定的理论和实践意义.     

过饱和信号交叉口的多目标控制模型

过饱和条件下信号交叉口优化控制往往是采用可以接受的最大信号周期,忽略了其他性能指标,并非真正意义上的最优.以典型的十字交叉口、四相位信号控制为例,根据车辆初始排队长度、车辆实时到达率和离开率,通过对各进口道的延误、通行能力及排队长度分析,建立了过饱和条件下以平均车辆延误最小、通行能力最大、平均车辆排队长度最小为目标函数的多目标信号优化控制模型.该模型以实时交通流的到达情况为依据进行实时优化,不仅考虑了交叉口的交通效率,还考虑了其效益指标,为研究过饱和条件下交叉口的多目标分析提供了有用信息.     

非强占优先权的离散时间排队系统分析

考虑了非强占优先机制的离散排队系统.高优先权和低优先权顾客分别以几何分布到达系统,服务时间服从一般分布.求出了系统存在稳态分布的充分必要条件.利用补充变量法,求出了系统稳态时高优先队列和低优先队列队长的概率母函数以及其他一些排队指标.     

一种收费站排队模型的模拟实现

对于简单的排队系统,可以直接用排队理论的相关公式来研究,当排队系统到达间隔时间和服务时间的概率分布很复杂时,就需用计算机模拟来求解.利用交通流量对时间的函数F(t),对排队模型进行计算机模拟,并给出了相应的算法和仿真实现.     

具有服务优先级别的动态离散泊位调度优化

研究具有不同服务优先级别的船舶动态到达情形下的离散泊位调度问题.以泊位分派和船舶作业开始时间为决策变量,为优化码头作业效率和船公司客户满意度,以最小化船舶总在港时间与加权延迟时间之和为目标建立数学模型.采用基于修改后的先到先服务等规则的启发式算法生成初始解,以此为基础设计结合禁忌深度搜索和模拟退火算法框架的混合算法对问题进行优化求解.不同问题规模下的数据仿真试验表明,该算法可以快速、有效地解决此类问题.     

过饱和信号交叉口的多目标控制模型

过饱和条件下信号交叉口优化控制往往是采用可以接受的最大信号周期,忽略了其他性能指标,并非真正意义上的最优。本文以典型的十字交叉口、四相位信号控制为例,根据车辆初始排队长度、车辆实时到达率和离开率,通过对各进口道的延误、通行能力及排队长度分析,建立了过饱和条件下以平均车辆延误最小、通行能力最大、平均车辆排队长度最小为目标函数的多目标信号优化控制模型。该模型以实时交通流的到达情况为依据进行实时优化,不仅考虑了交叉口的交通效率,还考虑了其效益指标,为研究过饱和条件下交叉口的多目标分析提供了有用信息。     

带有等待时间窗的补给运输船航路规划

在渔船补给运输工作过程中,补给运输方案的选择对运输成本和效率有着至关重要的作用.为了降低补给运输的成本和提高运输效率,提出了一种以减少运输距离和运输作业时间为目标的航路规划方法.首先分析了渔船补给运输船的工作方式,以"送报男孩"方式作为补给策略.在此基础上,采用回归分析法预测渔船完成生产任务的初始等待时间,建立了以最短航路和最少补给时间为目标的多目标优化模型.鉴于模型决策变量的多维性,设计了模型求解的禁忌搜索算法,最后通过算例仿真验证了模型的可行性.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the