Research on passenger flow control at metro transfer stations based on real-time flow calculation of streamlines

Purpose – The volume of passenger traffic at metro transfer stations serves as a pivotal metric for theorchestration of crowd flow management. Given the intricacies of crowd dynamics within these stations andthe recurrent instances of substantial passenger influxes, a methodology predicated on stochastic processesand the principle of user equilibrium is introduced to facilitate real-time traffic flow estimation within transferstation streamlines.Design/methodology/approach – The synthesis of stochastic process theory with streamline analysisengenders a probabilistic model of intra-station pedestrian traffic dynamics. Leveraging real-time passengerflow data procured from monitoring systems within the transfer station, a gradient descent optimizationtechnique is employed to minimize the cost function, thereby deducing the dynamic distribution of categorizedpassenger flows. Subsequently, adhering to the tenets of user equilibrium, the Frank–Wolfe algorithm isimplemented to allocate the intra-station categorized passenger flows across various streamlines, ascertainingthe traffic volume for each.Findings – Utilizing the Xiaozhai Station of the Xi’an Metro as a case study, the Anylogic simulation softwareis engaged to emulate the intra-station crowd dynamics, thereby substantiating the efficacy of the proposedpassenger flow estimation model. The derived solutions are instrumental in formulating a crowd controlstrategy for Xiaozhai Station during the peak interval from 17:30 to 18:00 on a designated day, yielding crowdmanagement interventions that offer insights for the orchestration of passenger flow and operationalgovernance within metro stations.Originality/value – The construction of an estimation methodology for the real-time streamline traffic flowaugments the model’s dataset, supplanting estimated values derived from surveys or historical datasets withreal-time computed traffic data, thereby enhancing the precision and immediacy of crowd flow managementwithin metro stations.

Environmental monitoring and fuzzy synthetic evaluation of municipal solid waste transfer stations in Beijing in 2001-2006

Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW TSs.Discharged wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results of...

Optimal Operation for Baoying Pumping Station in East Route Project of South-to-North Water Transfer

Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes （namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge）, the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge.

Comparative Analysis on Observation Data of the Transfer Station in Nanning National Weather Station

[Objective] The research aimed to analyze difference of the observation data by transfer station in Nanning National Weather Station. [Method] By using observation data (atmospheric pressure, temperature, relative humidity, wind direction and speed, precipitation, sunshine, etc.) from January to December in 2000 at old and new Nanning National Weather Station, difference of the each meteorological factor was contrasted. Main reason for difference of the each meteorological factor was analyzed from altitude, underlying surface property and station environment. [Result] Atmospheric pressure and temperature at new station were both lower than that at old station, while relative humidity and wind speed were both higher than that at old station. Rainfall and sunshine had big differences at new and old stations, but variation did not have rule. Main reasons for obvious difference of the meteorological factor were that altitude, observation environment, terrain and underlying surface property at new and old stations were different. Influences of the altitude and observation environment were especially significant. [Conclusion] The research provided basis for continuity and homogeneity correction of the data sequence at Nanning National Weather Station.

Investigation and Analysis of Satisfaction of Rail Transit Transfer Station Facilities in Changchun

The comfort satisfaction of basic facilities of the rail transit transfer station will influence pedestrian choice of vehicle. Aiming at the problem of traffic jams in Changchun in China, we designed a satisfaction questionnaire to investigate the factors which might affect the pedestrian satisfaction in rail transit transfer station in Changchun. By using the statistical methods, including correlation analysis, factor analysis and comparative analysis of satisfaction and importance, we analyzed the survey data, and get the results of analysis. Some suggestions for rail transit transfer station based on the results are given.

Performance enhancement of water bath heater at natural gas city gate station using twisted tubes

Natural gas is transported from producing regions to consumption regions by using transmission pipelines at high pressures. At consumption regions, the pressure of natural gas is reduced in city gate stations(CGSs). Before the pressure reduction process, the temperature of natural gas is increased usually by using a water bath heater,which burns natural gas as fuel, to protect against freezing of natural gas. These types of heat exchangers have a low efficiency and consume a lot of fuel to generate the required heat. In the current study, the twisted configuration of the heating coil is proposed and investigated to enhance the heat transfer through a water bath heater with a nominal capacity of 1000 m^3·h^-1. Firstly, the implementation procedure is validated with data collected from the CGS of Qaleh-Jiq(located in Golestan province of Iran). A very good agreement is achieved between the obtained results and the real data. Then, three different twist ratios are considered to examine the twisting effects. The proposed technique is evaluated in the terms of velocity, temperature, and pressure variations, and the results are compared with the conventional case, i.e. straight configuration. It is found that both the heat transfer rate and the pressure drop augment as the twist ratio is raised. Finally, it is concluded that the twisted tubes can reduce the length of the gas coil by about 12.5% for the model with low twist ratio, 18.75% for the model with medium twist ratio, and 25% for the model with high twist ratio as compared to the straight configuration.

The anomalous reactions of the geomagnetic horizontal field transfer functions before Tangshan earthquake

We have collected the data of variometers in period from 1972 through 1984 at Changli and Baijiatuan stations. The results calculated from 19 groups of data show: 1) There are no significant anomalies of A, B at Baijiatuan and that of B at Changli, but there are evident anomalous changes for A u, A v at Changli station. This result basically agrees to the a, b calculated using the method of measuring magnetograms, which demonstrates that the anomalies limited in the aftershock area and its neighbouring regions. 2) There are some changes of the inter station transfer functions of C u, C v, F u, F v before Tangshan earthquake, and the changes of the image parts C v, F v are more obvious, which is in agreement with the research results for Hualian earthquake. However, according to the results of Carlisle M =5.0 earthquake by Beamish(1982), the real parts F u, C u change more significantly.

On the problems concerned in“The subter－ranean electrical conductivity structure at the ChineseGreatWalStationonAntarctic（CG┐WSA）”byXiaopingZeng，YunfangLinandYuechenZhao

By means of the Capon spectral analysis technique calculated the frequency response of the geomagnetic transfer functions for the Chinese Great Wall Station on Antarctic, and made a preliminary inference for the underground electrical conductivity structure. In the present note, the writer considers that there are some problems concerned in their paper. Maybe it is worthwhile discussing these problems as below.

低频导波检测技术在输油场站应用的效果分析

本文主要是对低频导波检测技术原理和应用进行分析,进而选取本次最优开挖验证点,通过MsS长距离超声导波检测仪在姬塬外输总站管网腐蚀检测过程中的应用效果分析,判断其应用效果具有哪些局限性和优缺点,为后续输油场站常规检测工作提供参考依据。

城市轨道交通大型换乘车站应急防灾设计

[目的]鉴于大型城市轨道交通(以下简称“城轨”)换乘车站数量不断增加,以及该类车站具有埋深较大、人员密集、逃生救援场地受限的特征,应急防灾难度和压力十分突出,因此需要对此类型车站的应急防灾进行设计。[方法]以武汉光谷广场综合体工程作为实际案例,从火灾防护、大客流防护、洪涝防护、恐袭防护及突发疫情防护等5个重点方面,分析大型城市轨道交通车站所面临的灾害特征,结合方案设计、模拟仿真、计算分析等方式,对不同类型的灾害提出解决方案。[结果及结论]采用开放式的建筑布局和贯通的人行交通层,结合自然排烟与下沉广场设置准安全区,是困难条件下大型地下空间的有效消防措施;结合车站特点分析客流高峰情况,对不同时段、不同类型的使用人群进行分类,并设置相对独立、交叉少的流线,以有效地进行大客流防护;除常规的洪涝防护措施外,提高与周边地下空间的硬隔离措施,如增加防淹门是作为洪涝防护的必要手段;提高站内的通透性,快速疏解乘客,避免堵塞滞留可有效防护恐怖袭击;对于突发疫情防护,应严格按照我国相关管理规定,落实日常防控管理,适时采取一般疫情或较大疫情响应措施。

安检模式对铁路客站换乘地铁效率的影响

随着新技术涌现和运用,铁路车站客流集散过程中的安检模式对于车站区域步行换乘效率的影响及其空间设计策略,正受到越来越多的关注。运用“MassMotion”软件对出站人流进行模拟,比较了采用“人脸识别无感出站”和“轨道交通安检互认”技术前后,对于不同空间节点人流出站情况的非均质影响及交互效应,并基于上述结果建立了出站空间人员压力速查表,为铁路车站前期设计评估提供参考。

主动配电网-充换电站群-智慧社区群分层优化调度策略

为解决配电网、社区、充换电站3个利益主体之间难以保障能量最优交换和信息安全问题,提出一种主动配电网充换电站群智慧社区群的分层优化调度策略。首先,结合用户侧的储能需求和电动汽车充换电站的运行优化需求,在满足配电网经济运行的前提下建立电动汽车充换电站、配电网和社区共同参与的共享储能模式,上层为主动配电网运行模型,下层为社区和充换电站运行模型;其次,考虑各储能充换电站之间的交通流、能量流的时空特性,利用卡车对各电动汽车充换电站间的电池进行灵活调度,建立基于移动式储能车的电池时空共享模型;然后,为解决多主体(即充换电站、配电网、社区)参与的调度框架难以实现总体最优的问题,引入交替方向乘子法(alternating direction method of multipliers,ADMM)设计了社区充换电站配电网的3层能量共享模型;最后使用MATLAB对模型仿真编码求解。仿真结果表明:所提出的策略能够保障共享储能系统中各个主体隐私的安全性和用能的经济性,使能量共享形式更加多样化;可提高储能电池的使用效率和用能经济性,系统总成本降低了18%。

传热学实验教学改革探索与实践

基于多年的传热学授课经验,系统分析了传热学课程的特点,深入讨论了传热学实验教学中存在的问题。针对实验教学的硬件条件和教学激励措施,探索了提高实验教学质量的途径。传热学实验教学改革改进了实验硬件条件,提高了师生对实验教学的重视程度,激发了师生对实验教学的兴趣。经过初步教学实践,传热学实验教学效果显著提升,为进一步深化传热学及其他能动专业课程教学改革提供了参考。

基于组合赋权-云模型的城市轨道交通换乘站运营安全评估研究

换乘站作为城市轨道交通联络线网的载体,其运营安全状况是影响整个线网运营的关键因素。针对现有换乘站安全评估影响因素不全面、评价标准不完善等问题,构建换乘站运营安全评估指标体系,并引入直觉模糊二元语义改进最优最劣法确定指标权重。同时,在充分考虑主观评价的犹豫性和模糊性的基础上,提出基于云模型的定性语言定量化的重构方法,并通过对比综合云与标准云的相似度给出评估结论。以上海地铁龙阳路换乘站为例,构建影响龙阳路站运营安全的指标体系,得出龙阳路站运营安全水平及设备因素对其运营安全影响最大的新结论,验证该评估方法的有效性,为准确掌握轨道交通换乘站运营安全现状,提高运营安全水平提供理论支撑。

空间站舱段平转式转位方案设计与验证

根据我国空间站实验舱在转位前后对天/地指向不变的任务需求,提出舱段平转式转位方案,设计基于转位机构的舱段转位实现方案。转位期间,空间站组合体采用重力梯度被动稳定姿态飞行,解决姿态主动停控时空间站稳定指向的难题。通过设计选取合适的转位任务窗口,确保转位全程测控链路畅通、光照充足,以提高任务安全性和可靠性。地面试验和在轨实验舱转位任务实施,全面验证了空间站舱段平转式转位方案的正确性。

地下空间长距离送风中转站通风设计

针对送风系统存在众多分支导致的阻力不均、风量减小等问题,提出了设置中转站的送风方式。本文以长方体送风中转站为例,采用模拟和实验相结合的方法,研究了送风中转站的空气分布特性与设计参数。结果表明:送风中转站可以将系统最不利出口的流量偏差由124.01%降低至33.14%;送风中转站的出口数量对其阻力与流量均匀性的影响较大。在此基础上,给出了送风中转站的设计方法。

流固耦合作用下泵站大体积混凝土结构振动特性分析

在泵站运行过程中,由转轮和导叶之间水体的动静干扰所引起的压力脉动是引起泵站混凝土结构及机组振动的主要原因。现有关于泵站及水电站厂房的研究中,仅以数值参数形式表达脉动,并未真实反映流体与导叶间的相互水力干涉。采用有限元软件ADINA建立泵站混凝土结构、流道和流体的耦合三维模型,特别将机架、轴流泵等金属结构建入模型中,真实反映流体与固定导叶间的相互水力干涉,模拟脉动传递路径。分析了泵站大体积混凝土结构的振动特性,并对泵站运行安全性作出评价分析。研究结果可为工程实践提供参考。

考虑公交换乘的地铁常态化限流站点识别方法研究

目前地铁常态化限流站点选择的研究,未考虑线路运输能力限制以及客流损失问题,脱离实际运营而难以推广使用。为平衡地铁公司和车站的决策标准,减少常态化限流站点的数量,提出一种考虑公交换乘疏散客流的地铁常态化限流站点识别方法。首先构建由地铁-公交耦合网络拓扑模型,并分别从地铁网络化运营和公交换乘减少客流损失2个角度设计7个地铁站关键程度量化指标;验证系统的线性时不变特性,基于子网生成策略设计站点识别算法;最后以2018年1月某工作日北京市的乘客出行链数据为例,验证指标和算法设计的合理性,研究每10 min时变客流分布规律,对比2018年的实际方案,结果表明:初始网络可控性为0.057 5,识别准确度趋近于80%,准确率高且误判率低的限流站数量分别为67,70,73,78。将常态化限流站分为固定和备选2类,并提出了结合公交换乘引导、分批次限流的措施,从而为大城市地铁车站高峰时段的常态化限流方案决策提供参考。

地铁既有站换乘改造通信系统升级方案研究

地铁已形成网络化运营模式,换乘节点越来越多。因为规划等原因,建设较早的地铁线路没有预留后期换乘接入条件。因此,在新线建设过程中,往往伴随着新建站带来的既有车站换乘改造和升级。其中,通信传输系统的改移和升级建设是重点工作之一。通信系统是城市轨道的交通神经,包括公安通信系统,民用通信系统和专用通信系统等,支持控制中心与车站、车辆的信息往来,并为乘客提供稳定的通信服务。针对在既有线运行条件下,换乘站改造带来的通信设备改移以及通信扩容需求等问题进行方案探讨,提出公安传输系统增强型MSTP建设方案和骨干传输系统OTN建设方案。以北京地铁10号线西土城站为例进行方案设计,10号线西土城站与新建地铁昌平线南延(简称昌南线)相交,换乘站建筑结构及功能的改变,对通信系统的设备升级、机房部署等都提出了新的要求,本文将设计方案应用于该换乘项目,验证了所提方案的合理性,研究成果以期为其他既有站换乘改造的通信系统升级提供参考。

面向站口行人检测的改进型Yolov5s算法

针对现有站口行人检测方法难以在实时性与准确性之间均衡的问题,提出一种改进型的Yolov5s模型用于高效地检测站口行人.首先,基于EfficientNetV1改进提出轻量化主干网络EfficientNet_c,优化网络结构和基本单元堆叠次数,提高模型在浅层对小尺寸目标的特征提取能力和提取速度;其次,通过调整宽度因子为基础模型的1/2,改变模型特征层通道数,在较小的精度损失情况下降低模型参数量;再次,增加小目标检测层,优化模型特征提取能力,提高模型对小目标的敏感度和准确性;最后,利用迁移学习的方式优化模型,增强模型泛化能力,降低学习成本,进一步提升模型精度.在课题组收集的数据集上的实验结果表明,所提算法准确率为92.2%,模型参数量仅为1.4 M.在Tesla P100 GPU上的平均推理速度为7.7 ms,实现模型准确率和推理速度的提升.研究结果为地铁和火车站口的行人检测和流量统计提供了一种可行的解决方案.