具有线性变价格物资的库存优化模型

讨论一类带线性变价格物资的库存系统。以订购次数n为主要变量，分别就不允许缺货与允许缺货两种情形建立相应的库存优化模型。给出模型最优解存在的条件。并导出最优解的形式。     

(R,Q)库存策略下消耗件的协同订购方案优化

制定合理备件订购方案是降低消耗件库存费用,提高装备供应效能的有效途径. 针对目前军事装备典型的三级供应模式,根据协同供应链系统订购理论,以装备可用度为中心,建立了(R,Q)库存策略下的备件协同订购模型. 在随机订购延误时间情况下,通过引入拉格朗日因子对模型进行分解,采用启发式算法对模型进行优化求解. 通过算例给出了优化结果,对各项影响因素进行了分析. 优化结果符合实际,该方法能够为备件管理人员制定合理的备件方案提供决策依据.      

基于核心企业的三级库存优化控制模型

研究了基于核心企业的三级库存优化控制问题．假设一种产成品由多种原材料制成，市场需求在一定条件范围内与产品价格成线性关系，综合考虑各级的订购费、存贮费、缺货损失费，并适当考虑批量运输费用，以总费用最小为目标，建立三级库存优化模型来确定最佳订购时点和最优订货批量，并用穷举法来调整价格，让需求在适当范围内变动，找出最佳价格条件下的需求量，使供应链上总的库存费用最低、利润最高．     

定期信用支付期影响价格折扣的最优订购模型

针对支付期滞后和资金具有时值的情况,将基于订货间隔期约束的最优订购模型转化为一个无约束的费用最小化问题,对模型构建过程进行了简化,进而给出定期信用支付期影响价格折扣的最优订购模型,并推导了该模型的最优解,最后通过一个简单的算例进行了验证     

基于核心企业的三级库存优化控制模型

研究了基于核心企业的三级库存优化控制问题.假设一种产成品由多种原材料制成,市场需求在一定条件范围内与产品价格成线性关系,综合考虑各级的订购费、存贮费、缺货损失费,并适当考虑批量运输费用,以总费用最小为目标,建立三级库存优化模型来确定最佳订购时点和最优订货批量,并用穷举法来调整价格,让需求在适当范围内变动,找出最佳价格条件下的需求量,使供应链上总的库存费用最低、利润最高.     

需求依赖库存的生产库存系统的最优控制

针对现实生活中存在的库存刺激需求的现象,建立了生产库存系统的最优控制模型。模型中生产率和价格为控制变量,库存为状态变量,并且生产率是有界的,需求率同时依赖于库存和价格。运用最大值原理对模型进行求解,根据模型参数的不同取值,获得了三种可能的解,并对其进行了详细分析。最后将模型应用于具体算例,得到了系统状态的具体变化过程,通过与需求不依赖于库存的情形相比较,得到了需求依赖于库存所产生的影响。     

社区团购易耗农产品库存决策及协调策略

为解决易耗农产品在社区团购中的库存与协调决策问题,分析易耗农产品的社区团购模式及其库存特点,研究易耗农产品在社区团购中的库存决策问题,建立基于订货批量和再订购点的库存总成本模型.首先,分析订货提前期的影响,计算订货周期长度,改进存储模型并建立库存总成本模型;其次,针对模型特点,改进梯度下降算法,求解该成本模型的极值解,并通过线性回归法对模型参数进行灵敏度分析;最后,以某农产品为例进行参数敏感性分析.结果表明:产品高需求率对库存总成本的影响较明显,成本利用率随着产品日均需求率的增加而提高.     

供应链中时变需求的多种变质商品订购策略

针对供应链中时变需求的变质商品,建立了多品种的库存模型,通过该模型分别求得单独订购策略、统一定购策略和联合订购策略下的总成本函数,经过对这些总成本函数性质的分析,提出了多种变质商品的最优订购策略.最后给出了算例.算例结果表明:当附加订购成本占订购成本的比例较大时,集聚效应明显,最优的订购策略趋于联合订购;当附加订购成本占订购成本的比例很小时,最优的订购策略趋于统一订购;当订购成本增大时,订购次数减少,供应链中的循环库存增加;当库存成本或变质成本增大时,订购次数增大,供应链中的循环库存减少.     

邢台煤矿综采库物资合理库存方法的研究

本论文讨论了怎样用库存论解决煤矿物资库存问题,这个问题具有重要的经济意义。按邢台煤矿每年实际物资消耗量进行了A、B、C分类,该矿A+B类物资占总数的13.35％,而占用资金却占总资金额的95.88％,因此,研究的重点为A,B类物资。邢台煤矿物资消耗量是随机变化的,对统计资料进行分析发现:综采库物资消耗量94％服从负指数分布,只有6％服从正态分布。笔者参照国内外经验、根据邢台煤矿实际情况提出了A+B类物资采用(T、Q、SS、S)库存控制方法,而C类采用(T、S、S)库存控制方法。     

变库存费的变质性物品的EOQ模型

研究需求依赖于库存的变质性物质的存贮模型。考虑库存费的两种可能：A库存费的变化率为存储时间的函数;B库存费的变化率为存贮量的函数,讨论模型解的存在性和唯一性,找到了最优存贮策略。     

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.     

Design and analysis of generic LBS application developing platform

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.     

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