城市轨道交通BOT融资模式中的政府职能

阐述建设-运营-移交(BOT)项目成功的重要条件之一在于政府的积极参与和支持.结合我国第一个运用BOT融资模式建设的城市轨道交通的项目--深圳轨道交通4号线,从法律法规和监管角度,对轨道交通BOT实施过程中政府职能进行探讨,提出应该注意的问题和建议.     

保税物流园区设计

结合工程实例着重分析保税仓库建筑设计要点及保税物流园区的城市功能等.     

采用双互易边界元法进行三维声场特征值分析的近似函数研究

该文对应用双互易边界元法进行三维声场特征值分析时所用的近似函数进行了研究和讨论.分别以RBF函数、TPS函数和扩展的RBF和TPS函数作为近似函数对一长方体封闭空间声特征值进行了计算.计算结果表明:TPS函数得出的结果与其它函数相比是比较精确的,且收敛速度较快,但高次的TPS函数并没有显示出优势;TPS函数、扩展的TPS函数和RBF函数对于域内点的选取不太敏感.     

The econometric estimation of airports’ cost function

The econometric estimation of cost functions has been proposed in the literature as a suitable approach in order to obtain estimations of marginal costs, efficiency levels and scale elasticities for transport industries. However, regarding the airport industry, no significant attention has been paid in developing an airport-specific estimation methodology rather than adapting the procedures applied to other industries. The lack of comparable airport data is one of the causes which could explain the scarcity of this literature in the past, as well as the use of very limited approaches to explain airport technology. This paper tries to overcome these limitations by developing an airport-specific methodology to estimate a multi-output long-run cost function using an unbalanced pooled database on 161 airports worldwide. The specification of hedonically-adjusted aircraft operations, domestic and international passengers, cargo and commercial revenues in the output vector, as well as the calculation of input prices are discussed. Both technical and allocative inefficiencies are specified in the model using a Stochastic Frontier method that has been estimated through Bayesian Inference and Markov Chain Monte Carlo methods.     

A CONVERGENCE THEOREM ON THE MULTIVARIATE INTERPOLATING RATIONAL FUNCTIONS

１　ＴｈｅＵｎｉｖａｒｉａｔｅＣｏｎｖｅｒｇｅｎｃｅＴｈｅｏｒｅｍｏｎＲａｔｉｏｎａｌＩｎｔｅｒｐｏ－ｌａｔｉｏｎＡｒａｔｉｏｎａｌｆｕｎｃｔｉｏｎｒｎｍ（ｚ）ｉｓｓａｉｄｔｏｈａｖｅｔｙｐｅ（ｎ／ｍ）ｉｆｉｔｈａｓｔｈｅｆｏｒｍｒｎｍ（ｚ）＝ｐｎ（ｚ）／ｑｍ（ｚ），ｑｍ（ｚ）０ｗｈｅｒｅｐｎ（ｚ）ｉｓａｐｏｌｙｎｏｍｉａｌｏｆｄｅｇｒｅｅａｔｍｏｓｔｎａｎｄｑｍ（ｚ）ｉｓａｐｏｌｙｎｏｍｉａｌｏｆｄｅｇｒｅｅａｔｍｏｓｔｍ．Ｃｏｎｃｅｒｎｉｎｇｔｈｅｃｏｎｖｅｒｇｅｎｃｅｏｆｔｈｅ（ｎ／ｍ）…     

《史记》之谶

＂谶＂是能够灵验预测未来事情的图记和文字符号,往往被认为是上天表达灾祥的预言启示。文章归纳了《史记》之谶的类型,阐述了《史记》之谶的功用。     

南海神庙旅游资源开发中的地方政府职能定位

南海神庙是我国现存规模最大、保存最完整、“级别”最高的海神庙,但其旅游资源开发面临重重困难．本文深入分析神庙旅游资源开发中存在的问题,进而突出了地方政府在神庙旅游资源开发中应发挥积极作用．地方政府作用的发挥重点在：编制和执行南海神庙及周边环境保护规划,加大神庙及周边旅游配套设施建设,打造神庙旅游品牌、加强神庙旅游的宣传力度,地方政府应发挥南海神庙的日常营运管理职能等四个方面．     

Mental flexibility impairment in drivers with early Alzheimer's disease: A simulator-based study

After memory impairment, one of the most common troubles of early Alzheimer's disease (AD) is the impairment of executive functioning. However, it can have major consequences on daily life, notably on the driving activity. The present study focused on one important executive function involved in driving: mental flexibility; and considered how this impairment can affect driving. Ten patients with early AD were matched with 29 healthy older drivers. All participants were given an evaluation of mental flexibility through neuropsychological tests and an experimental test developed on a static driving simulator. The experiment was divided in two conditions; one without mental flexibility and another condition with a mental flexibility demand. AD patients showed impairments in the neuropsychological tests evaluating mental flexibility. These deficits are linked to the deficits they showed in the driving simulator flexibility tests. This study contributes to the understanding of mental flexibility mechanisms and on their role in driving activity. It also confirms that the driving simulator is a suitable tool to explore cognitive disorders and driving ability.     

Application of H∞ control in rudder/flap vector robust control of a ship''s course

Given the uncertainty of parameters and the random nature of disturbances that effect a ships course, a robust course controller should be designed on the basis of rudder/flap vector control. This paper analyzes system uncertainty, and the choice of weighting functions is also discussed. When sea waves operate on a ship, the energy-concentrating frequency varies with the angle of encounter. For different angles of encounter, different weighting functions are designed. For the pole of a nominal model existing in an imaginary axis, the bilinear-transform method is used. The "2-Riccati" equation is adopted to solve the H∞ controller. A system simulation is given, and the results show that, compared with a PID controller, this system has higher course precision and more robust performance. This research has significant engineering value.     

Application of H~∞ control in rudder/flap vector robust control of a ship's course

Given the uncertainty of parameters and the random nature of disturbances that effect a ships course, a robust course controller should be designed on the basis of rudder/flap vector control. This paper analyzes system uncertainty, and the choice of weighting functions is also discussed. When sea waves operate on a ship, the energy-concentrating frequency varies with the angle of encounter. For different angles of encounter, different weighting functions are designed. For the pole of a nominal model existing in an imaginary axis, the bilinear-transform method is used. The "2-Riccati" equation is adopted to solve the H∞ controller. A system simulation is given, and the results show that, compared with a PID controller, this system has higher course precision and more robust performance. This research has significant engineering value.