潜艇均衡系统自流注水调节阀稳态噪声试验研究

本文模拟建立了潜艇均衡系统自流注水试验系统,对不同假海压力、不同系统流量、不同出口背压及串联2台调节阀时自流注水稳定过程振动噪声进行研究。结果表明:潜艇均衡注水振动噪声随着假海深度的增大而增大;空气噪声随流量调节阀开度的增大而增大,在流量调节阀开度为60°-70°之间,振动加速度及水动力噪声产生峰值;在出口背压为0-0.5 MPa之间时,振动噪声值均大于无背压状态,峰值为0.2 MPa;串联2台流量调节阀可大幅降低自流注水振动噪声。     

浅谈FAS双中心建设及设备维护

重点分析了西安局集团公司由2K数调主系统组网更新改造为FAS双中心网络的建设方法,并根据日常维护经验,列举了调度台通道故障处理、FASB简易故障判断及计表倒换试验、FASA和FASB系统与MSC之间的业务故障处理等.     

Development and calibration of a long-distance passenger traffic assignment model

This paper studies the assignment of long-distance passenger traffic on a highway corridor network. First, we propose a traditional model for the long-distance traffic assignment considering interactions with local commuter traffic. It addresses the effect of local networks on highway corridors. An iterative algorithm is developed to solve for the exact solution. Then, to address the potential computational issues that arise therein, a decomposition method is proposed by introducing a new concept of corridor elasticity. An assignment procedure for long-distance passenger traffic is developed accordingly. Numerical tests show that the proposed decomposition method makes significant improvements in computational performance at a small loss of optimality. This decomposition method well approximates the exact assignment from the traditional formulation, especially when the highway corridors are near-saturation. The proposed decomposition method appears practical for application.     

景观道路的设计实践——广阳岛环岛路设计

广阳岛环岛路的主要功能是服务性景观路,跟环岛滨江公园一起,共同构筑广阳岛的滨江景观带。尝试引进了国外的宁静化设计,尽可能推行最生态的工程做法,努力创造人与自然相和谐的环境,并竭尽全力地将这些构想付诸实施。为了实现以上目标,道路、交通、排水、结构、桥梁和电照专业,在景观专业的组织下,共同展开了这条景观路的设计尝试。     

Tradable network permits: A new scheme for the most efficient use of network capacity

Akamatsu et al. (2006) proposed a new transportation demand management scheme called “tradable bottleneck permits” (TBP), and proved its efficiency properties for a single bottleneck model. This paper explores the properties of a TBP system for general networks. An equilibrium model is first constructed to describe the states under the TBP system with a single OD pair. It is proved that equilibrium resource allocation is efficient in the sense that the total transportation cost in a network is minimized. It is also shown that the “self-financing principle” holds for the TBP system. Furthermore, theoretical relationships between TBP and congestion pricing (CP) are discussed. It is demonstrated that TBP has definite advantages over CP when demand information is not perfect, whereas both TBP and CP are equivalent for the perfect information case. Finally, it is shown that the efficiency result also holds for more general demand conditions.     

公路建设项目征地拆迁补偿费用确定与控制方法研究

文中以广东省公路建设项目征地拆迁费用的确定为例,以现行实施的征地拆迁补偿相关规定为基础,探讨征地数量和标准的计量、计算方法,建立征地拆迁标准动态数据库,以期对征地拆迁费用的确定和控制提供思路和实际操作指导。     

考虑横向漂移的船舶路径跟踪自抗扰控制

针对船舶运动系统中内部动态不确定和外部干扰等问题,进行了欠驱动船舶路径跟踪的自抗扰方法研究。利用Backstepping设计参考航向角,并通过线性扩张状态观测器对流干扰和横向运动引起的横向漂移进行估计。其次,根据自抗扰算法对航向进行控制,采用线性扩张状态观测器对外界干扰及内部不确定项进行估计。最后仿真结果表明,在风流干扰下所设计的控制器仍能使船准确地跟踪上参考路径,验证了所提控制方案的有效性。     

基于多旅行商问题的应急设施服务区划分模型

基于多旅行商问题，增设集散中心需求及应急服务设施资源容量约束条件，以最小化遍历区域内全部集散中心的综合旅行时间成本为优化目标，构建一种应急设施服务区划分模型，确定各应急设施的服务区范围.设计一种复合算法求解模型，首先基于P-中值选址模型的优化理念，形成初始方案；继而加入禁忌搜索算法，结合LKH求解器对模型进行迭代优化求得最优解.基于宁波市北仑区实际拓扑网络进行案例分析，验证了模型和求解方法的有效性.