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891.
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893.
单点系泊系统作为浮式生产储油卸油装置(Floating Production Storage and Offloading,FPSO)的核心组成部分,需在FPSO进入安装现场之前完成安装,随后FPSO进入安装现场进行回接。以我国南海某具体工程项目为背景,全面、系统地介绍FPSO悬链腿单点系泊系统的安装及回接方法,并采用OrcaFlex分析软件对各个施工步骤进行相关的模拟分析。该单点系泊系统的整个安装过程可分为抓地锚安装、下段锚腿铺设、锚腿张紧、上段锚腿铺设、单点浮筒拖航及就位和锚系回接单点浮筒等6个阶段。 相似文献
894.
A new approach for improving the performance of freight train timetabling for single-track railways is proposed. Using the idea of a fixed-block signaling system, we develop a matrix representation to express the occupation of inter- and intra-station tracks by trains illustrating the train blocking time diagram in its entirety. Train departure times, dwell times, and unnecessary stopping are adjusted to reduce average train travel time and single train travel time. Conflicts between successive stations and within stations are identified and solved. A fuzzy logic system is further used to adjust the range of train departure times and checks are made to determine whether dwell times and time intervals can be adjusted for passenger and freight trains at congested stations to minimize train waiting times. By combining manual scheduling expertise with the fuzzy inference method, timetable efficiency is significantly improved and becomes more flexible. 相似文献
895.
文章分析了我国典型航线典型船舶排放特征,以船舶自动识别系统数据为基础,收集整理所选研究船舶排放参数,结合船舶实际航行资料,采用动力法估算了秦皇岛港—广州港航线某散货船一个航行周期的排放清单,并分析了靠港、停泊、港内机动、巡航4个船舶状态下的排放特征,绘制了2 km×2 km分辨率的空间排放特征图。结果表明,该典型航线上典型散货船舶一个航行周期排放的SOx、NOx、PM10、PM2.5总量分别为18.88吨、30.87吨、1.85吨和1.69吨。排放源分析表明从在船舶的主机、辅机和锅炉3种排放源中,主机是主要排放源。航行状态上巡航工况排放量最大;船舶排放污染物的空间分析表明,船舶在进出港口区域是污染物排放最密集的区域。 相似文献
896.
为了评价城市绿色交通,建立了城市绿色交通评价体系,包括环保性指标等3个评价项目和道路绿化率等8个评价指标,文章通过案例分析发现,价值函数法适用于城市绿色交通评价。采用专家打分法确定指标权重系数,并对指标进行无量纲化、同趋向化等处理,采用价值函数法计算评价体系得分。 相似文献
897.
《运输规划与技术》2012,35(8):868-880
ABSTRACTAnalysis of elevator traffic in high rise buildings is critical to the performance evaluation of elevator group control systems (EGCS). Elevator dispatching methods or parking algorithms in an EGCS can be designed or modified according to analyses of traffic flow. However, interpretation of traffic flow based solely on numerical data may not be explicit and transparent for EGCS experts as well as for other non-expert building administration. In this study, we present a model for visualization and analysis of elevator traffic. First, we present an alternative approach for traffic analysis which we call route visualization. In the proposed approach, we initially decompose elevator traffic into its component parts and investigate each component independently. Then, using superposition of components we obtain a reconstructed model of overall traffic. This modeling approach provides component-based traffic analysis and representation of routes with intensities through data visualization. In the second part we introduce a multi-dimensional analysis of time parameters in ECGS. This approach provides a comparative analysis of several control algorithms such as dispatch or park algorithms for different combinations of traffic components. 相似文献
898.
Augmented Reality “AR” is a promising paradigm that can offer users with real-time, high-quality visualization of a wide variety of information. In AR, virtual objects are added to the real-world view in real time. The AR technology can offer a very realistic environment for enhancing drivers’ performance on the road and testing drivers’ ability to react to different road design and traffic operations scenarios. This can be achieved by adding virtual objects (people, vehicles, hazards, and other objects) to the normal view while driving an actual vehicle in a real environment. This paper explores a new Augmented Reality Vehicle “ARV” system and attempts to apply this new concept to a selected traffic engineering application namely the left-turn maneuver at two-way stop-controlled “TWSC” intersection. This TWSC intersection experiment, in addition to testing the feasibility of the application, tries to quantify the size of gaps accepted by different driver’s characteristics (age and gender). The ARV system can be installed in any vehicle where the driver can see the surrounding environment through a Head Mounted Display “HMD” and virtual objects are generated through a computer and added to the scene. These different environments are generated using a well defined set of scenarios. The results from this study supported the feasibility and validity of the proposed ARV system and they showed promise for this system to be used in the field-testing for the safety and operation aspects of transportation research. Results of the left-turn maneuver study revealed that participants accepted gaps in the range of 4.0-9.0 s. This finding implies that all gaps below 4 s are rejected and all gaps above 9 s are likely to be accepted. The mean value of the left-turn time was 4.67 s which is a little bit higher than reported values in the literature (4.0-4.3 s). Older drivers were found to select larger gaps to make left turns than younger drivers. The conservative driving attitude of older drivers indicates the potential presence of reduced driving ability of elderly. Drivers’ characteristics (age and gender) did not significantly affect the left-turn time. Based on the survey questions that were handed to participants, most participants indicated good level of comfort with none or small level of risk while driving the vehicle with the ARV system. None of the participants felt any kind of motion sickness and the participants’ answers indicated a good visibility and realism of the scene with overall good system fidelity. 相似文献
899.
文章以新世纪大桥主桥钢桁架上构施工为例,对施工所需缆索吊装系统的承重主索、塔架、地锚、扣挂体系进行了介绍,并阐述了利用缆索吊装系统进行钢桁架拱桥上构施工的工艺流程及技术要点。 相似文献
900.