Pareto-improving congestion pricing and revenue refunding with multiple user classes

This study investigates Pareto-improving congestion pricing and revenue refunding schemes in general transportation networks, which make every road user better off as compared with the situation without congestion pricing. We consider user heterogeneity in value of time (VOT) by adopting a multiclass user model with fixed origin–destination (OD) demands. We first prove that an OD and class-based Pareto-improving refunding scheme exists if and only if the total system monetary travel disutility is reduced. In view of the practical difficulty in identifying individual user’s VOT, we further investigate class-anonymous refunding schemes that give the same amount of refund to all user classes traveling between the same OD pair regardless of their VOTs. We establish a sufficient condition for the existence of such OD-specific but class-anonymous Pareto-improving refunding schemes, which needs information only on the average toll paid and average travel time for trips between each OD pair.     

电子海图系统中叠加气象信息的矢量化方法研究

为了更好地保障船舶航行安全,将气象信息叠加到电子海图系统中,以便给航海人员提供决策依据。根据电子海图系统中图像数据的特点,文章提出一种将气象预报图等压线矢量化的方法。     

集装箱船能效运营指数研究

为了探寻国际海事组织船舶能效运营指数的影响因素,评价各种提高能效的措施,推导集装箱船船的能效运营指数估算公式,使用敏感性分析,量化航速、航程、载箱率、停泊时间等因素对指数的影响程度.结果表明,运营条件一定,船舶大型化有助于提高能效;在船型一定的前提下,采取降低航速,提高载箱率,增加港口效率等营运措施,有助于提高船舶运营效能.     

多Agent的船舶电力系统网络重构技术

Reconfigurability of the electrical network in a shipboard power system (SPS) after its failure is central to the restoration of power supply and improves survivability of an SPS. The navigational process creates a sequence of different operating conditions. The priority of some loads differs in changing operating conditions. After analyzing characteristics of typical SPS, a model was developed used a grade III switchboard and an environmental prioritizing agent (EPA) algorithm. This algorithm was chosen as it is logically and physically decentralized as well as multi-agent oriented. The EPA algorithm was used to decide on the dynamic load priority, then it selected the means to best meet the maximum power supply load. The simulation results showed that higher priority loads were the first to be restored. The system satisfied all necessary constraints, demonstrating the effectiveness and validity of the proposed method.     

大型舰船电力系统潮流计算方法(英文)

The effect of line voltage drop is considered larger on loads, especially on asynchronous motor, transformers and other non-linear load parameters in power system of large ships. A novel power flow method based on improved node voltage method is proposed, and a typical ship power system, which has 2 power stations and 10 nodes, with closed-loop design but open-loop operation, is taken as an example. Simulation results show that the improved power flow calculation method has achieved higher accuracy and better convergence.     

快艇气泡减阻的原理研究与相似比分析

分析了高速气泡船气液两相流动的特征,进而将气泡船复杂的三维流动简化为两维人工气泡绕流的两相流物理模型,并提出了两维人工气泡绕流的相似律.采用有限体积法和VOF方法,建立了两维人工气泡绕流的数学模型.应用该数学模型,研究了气泡船在无气泡、气泡封闭、气泡半开三种典型绕流时的气液流场特性,得到了气泡长度、气泡形状随来流速度、气泡腔压力、气体流量的变化规律,分析得出了在高速气泡船底部形成稳定气泡的力学条件.相关研究结果对高速气泡船底部气泡腔的设计具有指导意义.     

The Implementation of Mirror-Image Effect in MPEG-2 Compressed Video

Straightforward techniques for spatial domain digital video editing (DVE) of compressed video via decompression and recompression are computationally expensive. In this paper, a novel algorithm was proposed for mirror-image special effect editing in compressed video without full frame decompression and motion estimation.The results show that with the reducing of computational complexity, the quality of edited video in compressed domain is still close to the quality of the edited video in uncompressed domain at the same bit rate.     

PERFORMANCE EVALUATION OF CHINESE NEW FUNDS

Introduction　　 Recent years have witnessed rapid growth ininvestment funds all over the world. This hasmade the mutual fund a more popular investmentvehicle for more investors. And the managed fundperformance becomes a subject of increased inter-est. Many researches have been done in this field,but much controversy still exists in both the theo-retical and empirical results[1～ 9] .Chinese new funds were found in1 998,andafter that,they experienced dramatically growth.In 1 998,only 6closed-…     

公路工程建设中征地及重新安置计划编制概要

简要介绍了公路工程建设中征地及重新安置计划的编制概要 ,以供今后在其他公路工程项目实施时在此方面参考。     

模糊专家系统模型在远程教学中的应用研究

在远程教学系统中,为了判断学生的知识缺陷类型并有针对性的指导学生再学习,利用模糊知识框架表示属性值,并提出了模糊匹配隶属函数uAj(x)的计算方法.