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991.
结合栾家口港区2×5万吨级散杂货泊位设计,介绍了靠山临海老港区在狭窄陆域和已有航道条件下总平面布置的特点,提出了设计中注意结合原港区的功能分区进行平面布置,码头轴线的确定和进港航道的选取等问题。同时针对港口总体规划,在引堤宽度、陆域面积、航道规划方面提出了建议。  相似文献   
992.
Over the past few years, much attention has been paid to computing flows for multi-class network equilibrium models that exhibit uniqueness of the class flows and proportionality (Bar-Gera et al., 2012). Several new algorithms have been developed such as bush based methods of Bar-Gera (2002), Dial (2006), and Gentile (2012) that are able to obtain very fine solutions of network equilibrium models. These solutions can be post processed (Bar-Gera, 2006) in order to ensure proportionality and class uniqueness of the flows. Recently developed, the TAPAS, algorithm (Bar Gera, 2010) is able to produce solutions that have proportionality embedded, without requiring post processing. It was generally accepted that these methods for solving UE traffic assignment are the only way to obtain unique path and class link flows. The purpose of this paper is to show that the linear approximation method and some of its variants satisfy these conditions as well. In addition, some analytical results regarding the relation between steps of the linear approximation algorithm and the path flows entropy are presented.  相似文献   
993.
This paper proposes a bi-level passenger transport market model taking into account competition between air and high-speed rail (HSR) in a domestic market. The paper discusses the characteristics of the relationship between market share and connectivity in domestic and international markets. The result suggests that because of the dominance of HSR in the domestic market, when connectivity between air and HSR is good, international passenger’s welfare can be improved. Finally, when considering profitability of the players, there is an incentive for airlines to cooperate with HSR, but there is no incentive for HSR to cooperate with airlines.  相似文献   
994.
This paper presents an integrated simulator “CUIntegration” to evaluate routing strategies based on energy and/or traffic measures of effectiveness for any Alternative Fuel Vehicles (AFVs). The CUIntegration can integrate vehicle models of conventional vehicles as well as AFVs developed with MATLAB-Simulink, and a roadway network model developed with traffic microscopic simulation software VISSIM. The architecture of this simulator is discussed in this paper along with a case study in which the simulator was utilized for evaluating a routing strategy for Plug-in Hybrid Electric Vehicles (PHEVs) and Electric Vehicles (EVs). The authors developed a route optimization algorithm to guide an AFV based on that AFV driver’s choice, which included; finding a route with minimum (1) travel time, (2) energy consumption or (3) a combination of both. The Application Programming Interface (API) was developed using Visual Basic to simulate the vehicle models/algorithms developed in MATLAB and direct vehicles in a roadway network model developed in VISSIM accordingly. The case study included a section of Interstate 83 in Baltimore, Maryland, which was modeled, calibrated and validated. The authors considered a worst-case scenario with an incident on the main route blocking all lanes for 30 min. The PHEVs and EVs were represented by integrating the MATLAB-Simulink vehicle models with the traffic simulator. The CUIntegration successfully combined vehicle models with a roadway traffic network model to support a routing strategy for PHEVs and EVs. Simulation experiments with CUIntegration revealed that routing of PHEVs resulted in cost savings of about 29% when optimized for the energy consumption, and for the same optimization objective, routing of EVs resulted in about 64% savings.  相似文献   
995.
996.
In this paper we use simulation to analyze how flight routing network structure may change in different world regions, and how this might impact future traffic growth and emissions. We compare models of the domestic Indian and US air transportation systems, representing developing and mature air transportation systems respectively. We explicitly model passenger and airline decision-making, capturing passenger demand effects and airline operational responses, including airline network change. The models are applied to simulate air transportation system growth for networks of 49 airports in each country from 2005 to 2050. In India, the percentage of connecting passengers simulated decreases significantly (from over 40% in 2005 to under 10% in 2050), indicating that a shift in network structure towards increased point-to-point routing can be expected. In contrast, very little network change is simulated for the US airport set modeled. The simulated impact of network change on system CO2 emissions is very small, although in the case of India it could enable a large increase in demand, and therefore a significant reduction in emissions per passenger (by nearly 25%). NOx emissions at major hub airports are also estimated, and could initially reduce relative to a case in which network change is not simulated (by nearly 25% in the case of Mumbai in 2025). This effect, however, is significantly reduced by 2050 because of frequency competition effects. We conclude that network effects are important when estimating CO2 emissions per passenger and local air quality effects at hub airports in developing air transportation systems.  相似文献   
997.

Sea space planning and congestion management is receiving more attention. However, little work on sea space capacity and strategy analyses can be found in the literature. Compared to other transportation systems, a sea space system has some special features that require consideration. The system capacity also depends on the pattern of traffic using the system. In this paper, we model a sea space as a directional network and capacity models for berthing areas, anchorage areas, fairways and their intersections, as well as the entire sea space system are developed. These models can be used to compute capacity for any given traffic pattern which can be extracted from vessel trip records or from traffic forecasts. To implement these models, a software system called Sea Space Capacity and Strategy Analysis System (SCSAS) has been developed in Visual C + + and is now being used in Singapore.  相似文献   
998.
The paper focuses on Network Traffic Control based on aggregate traffic flow variables, aiming at signal settings which are consistent with within-day traffic flow dynamics. The proposed optimisation strategy is based on two successive steps: the first step refers to each single junction optimisation (green timings), the second to network coordination (offsets). Both of the optimisation problems are solved through meta-heuristic algorithms: the optimisation of green timings is carried out through a multi-criteria Genetic Algorithm whereas offset optimisation is achieved with the mono-criterion Hill Climbing algorithm. To guarantee proper queuing and spillback simulation, an advanced mesoscopic traffic flow model is embedded within the network optimisation method. The adopted mesoscopic traffic flow model also includes link horizontal queue modelling. The results attained through the proposed optimisation framework are compared with those obtained through benchmark tools.  相似文献   
999.
通信系统的建设遵循技术成熟、经济适用、同时满足发展需要的原则,网络结构满足运营维护管理体制的要求,传输系统必须具备较高的网络保护和恢复能力。基于寿平铁路通信传输系统组网及益羊线既有运营维护管理体制,本次工程通信传输系统组网旨在保证业务的高度可靠。通过参照子网连接保护(SNCP)已广泛用于传输系统的组网案例,其适用于各种网络拓扑结构,倒换速度快,可实时切换工作通道和保护通道。为此,选用基于业务的SNCP作为本线传输系统的网络保护方式,以双发选收的原则保证通信传输业务的高度可靠,并在优化网络结构的同时,一定程度上提高益羊线传输系统的通道利用率。  相似文献   
1000.
陈恺  张银苗  韩非非 《水运工程》2013,(10):128-132
进港航道是港口水域平面设计中重要的环节,航道平面布置选线是港口航道设计的关键;液化天然气码头因其 货种特殊性,对船舶进出港航行安全保障要求高。结合实际工程,列出液化天然气码头进港航道平面布置设计思路;综合 考虑航道布置的平面约束因素,提出方案并进行比选,最后确定推荐方案,研究方法可为类似工程提供参考。  相似文献   
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