Congestion spill effects of Heathrow and Frankfurt airports on connection traffic in European and Gulf hub airports

We develop two stage fixed-effects single-spill and double-spill models for congestion connection spills of London Heathrow and Frankfurt airports on 9 hub airports in Europe and the Gulf. Our panel data covers connection traffic from 1997 to 2013 for Heathrow and 1997 to 2011 for Frankfurt. The single-spill results support strongly that the connection spills from Heathrow’s capacity limitations do strengthen competing hub airports of major alliance groups and to a lesser degree one Gulf hub. The double-spill model for Heathrow and Frankfurt shows nearly asymmetric overall spill characteristics between the two airports. Our results underline the influence of airline network strategies on congestion spills as European airline networks are shaped by alliances and umbrella mergers. Thus, the airline network perspective in airport capacity expansion decisions needs to play a greater role, as indicated by our asymmetric results for overall spill effects between Heathrow and Frankfurt airports.     

海洋保障基地码头设计要点

以某海洋保障基地码头设计为案例,分析该类码头的功能、特点,提出"设计要满足后方保障条件尽量完善,作业天数和港内安全停靠天数要尽量多,要设置防台锚地,有别于一般港口码头",为今后同类型码头设计提供借鉴。     

随机-区间混合不确定性下FRP桁架桥多尺度可靠性分析

桁架结构是FRP材料在新建桥梁结构中应用的主要形式之一,然而由于缺乏设计规范、分析方法和数据信息等,FRP桥梁结构存在真实安全度模糊的问题.针对FRP桁架桥在细-宏观尺度参数均存在不确定性,且同时存在随机不确定性和由于概率信息缺乏而表达为非概率不确定性的问题,提出一种多尺度混合可靠性分析方法,该方法能够处理在概率和非概...     

Extreme value prediction of nonlinear ship loads by FORM using Prolate Spheroidal Wave Functions

In this study, a method for predicting the extreme value distribution of the Vertical Bending Moment (VBM) in a flexible ship under a given short-term sea state is presented. The First Order Reliability Method (FORM) is introduced to evaluate the Probability of Exceedances (PoEs) of extreme VBM levels. The Karhunen-Loeve (KL) representation of stochastic ocean wave is adopted in lieu of the normal wave representation using the trigonometric components, by introducing the Prolate Spheroidal Wave Functions (PSWFs) to formulate the wave elevations. By this means, reduction of the number of stochastic variables to reproduce ocean wave is expected, which in turn the number of computations required during FORM based prediction phases is significantly reduced. In this study, the Reduced Order Model (ROM), which was developed in our previous studies, is used to yield the time-domain VBMs along with the hydroelastic (whipping) component in a ship. Two different short-term sea states, moderate and severe ones, are assumed. The FORM based predictions using PSWF for normal wave-induced VBM are then validated by comparing with those using the normal trigonometric wave representation and Monte Carlo Simulations (MCSs). Through a series of numerical demonstrations, the computational efficiency of the FORM based prediction using PSWF is presented. Then, the validation is extended to the severe sea state where the whipping vibration contributes to the extreme VBM level to a large degree, and finally the conclusions are given.     

一种采用输移浓度为主要参数的泥石流流量计算新方法

根据沟床水力条件对泥石流浓度的调节作用和泥石流浆体浓度对沟槽输移能力所具有的重要影响。建立了由流域产沙条件来估计浆体浓度，再由沟槽输移浓度来确定泥石流流量的新方法。经过比检验。计算流量与形态调查流量相近，平均相对误差为－６．９％，最大相对误差为－１４％。     

高维欧氏空间上无界连续函数逼近的渐近公式

利用扩展乘数法讨论了高维氏空间上线性正算子改造为逼近多元无界连续函数的渐近估计，给出了具有一般性的渐近公式，作为实例研究了多元非乘积型的Landau多项算子逼近多元无界连续函数的渐近估计式，推广了前人的若干结论。     

新时期西部高速公路养护管理发展问题研究

从管理体制、技术规范方面梳理、剖析了我国高速公路养护管理发展过程中的问题；对美国、日本、法国等国外高速公路养护管理体制现状科学深入分析，并以借鉴；基于再次分析，按管养经费核算、作业关系、管理职能分类考察，对我国高速公路养护管理制度做出多线性的把握。提出进一步研究的方向，在市场运行机制下更好地为道路使用者服务的养护管理体制和科学可行的评价体系奠定基础。     

一种转印新工艺在贴花上的应用

考虑到摩托车的使用方式和使用环境，要求转印贴花必须具有耐久性、耐腐蚀及耐汽油性，因而油墨的选择及印刷过程控制与原转印工艺要求存在较大不同，同时水转印工艺的粘贴过程与现行贴花粘贴工艺过程也存在差异。经与转印生产厂家的进一步协调，按照现行喷漆及粘贴工艺对水转印工艺作适应性改进和提高，做出的成品外观相对于传统工艺有了质的改变，现阶段正在做耐久性实验，相信不久，中国摩托车贴花将以新的面孔面市。     

阻尼车轮减振降噪的试验研究

对国内标准客车车轮外侧表面进行约束型阻尼处理,试制出由基层(KKD型标准客车车轮)、阻尼层和约束层3部分组成的阻尼车轮样品。在实验室实测标准车轮、阻尼车轮的振动传递函数和噪声级,分析阻尼车轮的减振降噪效果。试验结果表明:阻尼车轮具有良好的减振降噪效果,在1 200~5 000 Hz频段内,阻尼车轮较标准车轮的振动传递函数幅值有较大幅度下降,沿车轮结构传递的振动减小;在径向和轴向激励条件下,总噪声级降低达10 dB以上。该阻尼车轮在制作上工艺简单,无须对结构进行改造,具有良好的应用前景。     

一类奇异积分算子与无界连续函数逼近

利用扩展乘数法建立了Мцракъян算子逼近全实轴上任意无界连续函数的收敛性定理，给出了具有一般性的结论，从而推广了前人的若干重要定理．