基于多属性决策的PCAS-SNIF关键节点分析

预先计划的近距空中支援(PCAS)是一种典型的空军进攻作战样式,在现代战争中有着举足轻重的作用,研究PCAS信息流转过程对于提高PCAS的作战效能具有重要意义。针对PCAS作战过程难以建模分析的问题,引入超网络理论,通过研究PCAS作战的基本流程以及作战网络中各节点之间的交互关系,构建了“两层五网”的PCAS信息流转超网络模型。之后,仿真分析了PCAS信息流转超网络节点的度中心性、介数、聚类系数和接近中心性4个方面的拓扑特性,通过多属性决策节点重要性综合评价方法得出网络关键节点。最后,通过网络攻击实验验证了超网络模型和多属性决策算法的合理性和有效性,为研究作战信息流转问题提供了新的思路。     

基于改航策略的空域流量管理研究

为减少危险天气下的航班延误现象,结合地面等待以及改航策略实施空域流量管理.将受危险天气影响的扇区视为流量约束区,根据扇区受危险天气影响的情况,以最小总延误成本为目标,流量约束扇区容量、起飞机场容量、流量约束扇区进入点的安全时间间隔为约束,建立基于改航策略的空域流量管理模型,并采用遗传算法对模型求解.通过算例进行仿真,仿真结果表明,基于改航策略的空域流量管理可以有效减少航班延误时间,提高航班运行的总体经济效益.     

互通立交单车道入口小客车运行速度模型

为了确定高速公路互通式立交单车道入口小客车运行速度特征,计算小客车在高速公路互通式立交入口处的运行速度模型,确保车辆在衔接段运行速度之间的协调,使车辆安全运行,在分析高速公路互通立交单车道入口处小客车运行速度实测数据基础上,得出小客车在入口处运行规律。使用链式开普勒雷达测速仪对入口处小客车速度进行实时采集,选取8条匝道特征点(合流鼻、合流点以及加速车道终点)处自由流状态下小客车速度作为分析样本,采用K-S检验对所取样本进行正态分布检验,在满足检验要求并分析三角区段和加速换道段速度及加速度特性后,确定自变量参数。最后利用SPSS软件进行回归分析,分别建立了小客车在合流点及加速车道终点处运行速度预测模型,并用4条匝道对模型进行了验证。研究结果表明:合流点处车辆运行速度与合流鼻速度及三角区段长度呈正相关,与平曲线半径倒数呈负相关;加速车道终点处运行速度与合流鼻速度及加速换道段长度呈正相关,与平曲线半径倒数呈负相关;模型通过了回归等式及回归参数显著性和平均相对误差检验,模型预测值与实测值相对误差平均值均小于10%,所建模型满足精度要求。研究结果对《公路项目安全性评价规范》(JTG B05—2015)中车辆运行速度相关规定进行补充说明,为高速公路安全性评价及设计提供理论支撑与参考。     

基于PCA的对等网络流量时空特性监测

在对等网络中,节点可以动态地进入和离开网络,增加了业务监测的难度。该文提出了采用主成分分析(PCA)方法检测并分析对等网络流量特征,解释了流量协方差矩阵最大特征值和最大特征矢量的物理意义,同时定义权重矢量作为流量观测指标,利用流量的协方差矩阵最大特征值和特征向量给出了全网的P2P流量时间和空间的动态特性。仿真结果表明,该方法能够很好地识别P2P流量的动态时间和空间特性,为互联网流量检测提供了一种有效方法。     

空中高速路匝口流量控制

空中高速路系统有助于缓解日益严重的空中交通拥挤问题.从空中高速路及其匝口的基本概念入手,基于元胞传输理论建立了空中高速路匝口流量控制模型,通过对模型进行仿真求解,建立匝口元胞连接图,得到系统最短时间、系统清空时间、最优匝口流量分布等,结果表明:该模型既能够满足空中高速路匝口流量控制建模的需要,又能反映空中高速路系统中交通流的动态特性.     

城市快速路交通事故特性分析与安全评价

通过分析济南市快速路交通事故统计数据,分别从时空分布、事故形态、事故发生原因等角度探究了城市快速路交通事故的特性。通过提取事故发生前5 min内的车型比数据和交通流量数据,并分析其与交通事故之间的规律性特征,构建基于色阶图的事故风险安全评价表,根据概率统计模型推算出事故发生的临界流量,最后综合以上数据分析构建快速路事故风险安全评价模型。数据拟合结果表明,根据当前交通流量和车型比例实时评估快速路的交通流运行安全风险,可以通过调控当前交通流量对可能发生的事故进行预警。针对快速路交通事故规律和特点,提出了事故预防及安全管理对策与措施,以达到预防事故发生、提升快速路运行安全水平的目的。     

基于管制员决策过程的空中高速路匝口控制模型

空中高速路系统有助于缓解日益严重的空中交通拥挤问题。依据管制员工作负荷首次将高速路设定服务水平,选定服务水平后即得到高速路的最大容量,通过计算高速路的最大容量与高速路实际流量差额来寻求最佳入口匝口流量调节率。同时针对控制周期内匝口处飞机到达数、匝口等待区容量以及总的交通需求情况,从管制员决策过程角度对匝口调节率进行修正,得到最终匝口调节率计算模型。通过对模型仿真表明:该模型能够满足空中高速路匝口流量控制,相比较时隙分配模型更符合实际管制工作中的流量控制需求。     

高速公路入口匝道合流区的CP-CS融合模型

为有效地评估高速公路现有或预建入口匝道合流区的交通安全性,提出了一种综合考虑冲突概率(CP)与冲突严重性(CS)的CP-CS融合模型。首先,考虑车辆微观运行特征对交通冲突的影响,构建了冲突概率模型;然后,利用统计数据集成冲突概率与冲突严重性,建立了CP-CS融合模型;最后,结合实测交通数据,采用SSAM交通冲突仿真分析验证所建模型的有效性,并基于案例研究揭示合流区风险系数演变机理,明确不同优化方案下合流区的安全状态。实验结果表明:文中模型有助于提高现有或预建入口匝道的安全水平;当主线车流速度小于27 m/s,每小时流量低于1 000辆时,合流区具有较高的通行效率与安全水平。     

最小费用最大流维度拓展及其在反洗钱中的应用研究

本文借助最小费用最大流理论对时间压力下最小风险最大流问题进行了研究,分析了最小风险、最大流路径下的最短时间,构建了基于时间压力条件下的最小风险最大流模型,利用多目标规划方法给出了求解该模型的算法,最后通过实例验证了该方法的有效性.     

基于管制移交的多机场终端区离港航班时刻优化

针对多机场终端区飞行流量大,空域资源紧张的现状,结合基于航迹运行理论,提出基于管制移交间隔优化离港航班时刻的模型。模型以时刻调整成本最小化为目标,使离港航班在出港点处能够建立符合移交条件的纵向间隔,使用遗传算法求解,利用北京终端区下辖三座机场的历史运行数据验证模型的适用性。结果表明,优化后的时刻可使98.15%的离港航班在出港点处建立符合移交条件的间隔,有效降低了因不满足移交间隔造成的飞行冲突,提高了航班流的有序性。     

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.     

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.     

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