scholarly journals Service-Oriented Load Balancing Approach to Alleviating Peak-Hour Congestion in a Metro Network Based on Multi-Path Accessibility

2019 ◽  
Vol 11 (5) ◽  
pp. 1293 ◽  
Author(s):  
Zhiyuan Huang ◽  
Ruihua Xu ◽  
Wei Fan ◽  
Feng Zhou ◽  
Wei Liu
Keyword(s):  
Load Balancing ◽  
Line Segments ◽  
Safety Risks ◽  
Effective Manner ◽  
Service Oriented ◽  
Metro Systems ◽  
Deletion Algorithm ◽  
Alternative Routes ◽  
Shanghai Metro ◽  
Metro Network

To further improve the service quality and reduce safety risks in current congested metro systems during peak hours, this paper presents a load balancing (LB) approach so that available capacity can be utilized more effectively in order to alleviate peak hour congestion. A set of under-utilized yet effective alternative routes were searched using a deletion algorithm (DA) in order to share the passenger loads on overcrowded metro line segments. An optimization model was constructed based on an improved route generalized time utility function considering the penalties of both in-vehicle congestion and transfers. A detailed load balancing solution was generated based on the proposed algorithm. A real-world example of three overloaded metro line segments in the Shanghai metro network were selected and used to verify the feasibility and validity of the developed load balancing method. The results show that the load balancing method can effectively reduce the overcrowding situation to a great extent. Finally, two prospective inducing schemes are discussed to help implement the load balancing solution in the actual metro system in an efficient and effective manner.

Some Aspects of Reliability Estimation of Loosely Coupled Web Services in Clustered Load Balancing Web Server

2020 ◽  
pp. 198-209
Author(s):  
Abhijit Bora ◽  
Tulshi Bezboruah
Keyword(s):  
Load Balancing ◽  
Goodness Of Fit ◽  
Web Server ◽  
Experimental System ◽  
Reliability Estimation ◽  
Loosely Coupled ◽  
Server Side ◽  
Quality Aspects ◽  
Service Execution ◽  
Service Oriented

Reliability of loosely coupled services through the paradigm of service-oriented computing and observing their fault tolerance against massive load in clustered load balancing web server plays an important role while evaluating the quality aspects of software-as-a-service (SaaS), grid, and distributed systems. This chapter shows some aspects of service execution while observing their failure records against massive execution of server-side instruction. A novel reliability estimation framework is proposed that can be deployed for evaluating the reliability of service execution over clustered load balancing web server. A load generating tool is used to generate massive load over the service execution. In this study we will discuss an experimental system and its architecture by using clustered load balancing web server, the reliability estimation framework along with the goodness of fit study through statistical analysis. The overall assessment of the work will validate the applicability of the proposed framework for the loosely coupled service in clustered load balancing web server.

scholarly journals Optimization of Bus Bridging Service under Unexpected Metro Disruptions with Dynamic Passenger Flows

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jiadong Wang ◽  
Zhenzhou Yuan ◽  
Yonghao Yin
Keyword(s):  
Disruption Management ◽  
Unexpected Events ◽  
Nsga Ii ◽  
Fleet Size ◽  
Proposed Model ◽  
Passenger Flows ◽  
Metro Systems ◽  
Bridging Strategy ◽  
Vehicle Capacity ◽  
Shanghai Metro

A metro disruption is a situation where metro service is suspended for some time due to unexpected events such as equipment failure and extreme weather. Metro disruptions reduce the level of service of metro systems and leave numerous passengers stranded at disrupted stations. As a means of disruption management, bus bridging has been widely used to evacuate stranded passengers. This paper focuses on the bus bridging problem under operational disruptions on a single metro line. Unlike previous studies, we consider dynamic passenger flows during the disruption. A multi-objective optimization model is established with objectives to minimize total waiting time, the number of stranded passengers and dispatched vehicles with constraints such as fleet size and vehicle capacity. The NSGA-II algorithm is used for the solution. Finally, we apply the proposed model to Shanghai Metro to access the effectiveness of our approaches in comparison with the current bridging strategy. Sensitivity analysis of the bus fleet size involved in the bus bridging problem was conducted.

A SDN-SFC-based service-oriented load balancing for the IoT applications

2018 ◽  
Vol 114 ◽  
pp. 88-97 ◽  
Author(s):  
Wei-Che Chien ◽  
Chin-Feng Lai ◽  
Hsin-Hung Cho ◽  
Han-Chieh Chao
Keyword(s):  
Load Balancing ◽  
Iot Applications ◽  
Service Oriented

Shanghai Metro Flow: Multiple Perspectives into a Subway System

Leonardo ◽  
2017 ◽  
Vol 50 (5) ◽  
pp. 511-512
Author(s):  
Till Nagel ◽  
Benedikt Groß
Keyword(s):  
Urban Mobility ◽  
Multiple Perspectives ◽  
Aesthetic Form ◽  
Subway System ◽  
Shanghai Metro ◽  
The City ◽  
Metro Network

One of the main characteristics of cities is the large amount of people moving around. These flows are reflected in all the subways dashing through the city. With the authors’ work, they strive to give an impression of this pulse of the city. They present Shanghai Metro Flow, consisting of an animated visualization composed of three scenes, each giving another perspective into the metro network, and an accompanying poster showing subway line details. Each visualization combines established techniques with a highly aesthetic form in order to attract people to observe and dwell on different aspects of urban mobility.

Elastic Optical Network Service-Oriented Architecture (SOA) Used for Cloud Computing and Its Resource Mapping Optimization Scheme

2020 ◽  
Vol 15 (4) ◽  
pp. 442-449
Author(s):  
Xun Xia ◽  
Ling Chen
Keyword(s):  
Cloud Computing ◽  
Load Balancing ◽  
Resource Utilization ◽  
Service Oriented Architecture ◽  
Optical Network ◽  
Spectrum Utilization ◽  
Mapping Algorithm ◽  
Resource Mapping ◽  
Elastic Optical Network ◽  
Service Oriented

In this study, starting from the elastic optical network, the layered and function isolated service-oriented architecture (SOA) is introduced, so as to propose an elastic optical network SOA for cloud computing, and further study the resource mapping of optical network. Linear mapping model, random routing mapping algorithm, load balancing mapping algorithm and link separation mapping algorithm are introduced respectively, and the resource utilization effect of different mapping algorithms for the proposed optical network is compared. During the experiment, firstly, the elastic optical network is tested. It is found that the node utilization and spectrum utilization of the underlying optical fiber level network are significantly improved. Within the average service time of 0.312 s∼0.416 s, the corresponding node utilization and spectrum utilization are 90% and 80% respectively. In the resource mapping experiment, load balancing algorithm and link separation algorithm can effectively improve the mapping success rate of services. Among them, the link separation mapping algorithm can improve the spectrum resource utilization of optical network by 15.6%. The elastic optical network SOA proposed in this study is helpful to improve the use of network resources.

scholarly journals An Integrated Energy-Efficient Operation Methodology for Metro Systems Based on a Real Case of Shanghai Metro Line One

Energies ◽  
2014 ◽  
Vol 7 (11) ◽  
pp. 7305-7329 ◽  
Author(s):  
Cheng Gong ◽  
Shiwen Zhang ◽  
Feng Zhang ◽  
Jianguo Jiang ◽  
Xinheng Wang
Keyword(s):  
Energy Efficient ◽  
Real Case ◽  
Efficient Operation ◽  
Metro Systems ◽  
Shanghai Metro

scholarly journals Cascading Failure Analysis on Shanghai Metro Networks: An Improved Coupled Map Lattices Model Based on Graph Attention Networks

2021 ◽  
Vol 19 (1) ◽  
pp. 204
Author(s):  
Haonan Ye ◽  
Xiao Luo
Keyword(s):  
Failure Analysis ◽  
Emergency Management ◽  
Cascading Failure ◽  
Coupled Map Lattices ◽  
Dynamic Behaviors ◽  
Attention Networks ◽  
Model Based ◽  
Metro Networks ◽  
Shanghai Metro ◽  
Metro Network

Analysis of the robustness and vulnerability of metro networks has great implications for public transport planning and emergency management, particularly considering passengers’ dynamic behaviors. This paper presents an improved coupled map lattices (CMLs) model based on graph attention networks (GAT) to study the cascading failure process of metro networks. The proposed model is applied to the Shanghai metro network using the automated fare collection (AFC) data, and the passengers’ dynamic behaviors are simulated by GAT. The quantitative cascading failure analysis shows that Shanghai metro network is robust to random attacks, but fragile to intentional attacks. Moreover, there is an approximately normal distribution between instant cascading failure speed and time step and the perturbation in a station which leads to steady state is approximately a constant. The result shows that a station surrounded by other densely distributed stations can trigger cascading failure faster and the cascading failure triggered by low-level accidents will spread in a short time and disappear quickly. This study provides an effective reference for dynamic safety evaluation and emergency management in metro networks.

scholarly journals A Real-Time Timetable Rescheduling Method for Metro System Energy Optimization under Dwell-Time Disturbances

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guang Yang ◽  
Junjie Wang ◽  
Feng Zhang ◽  
Shiwen Zhang ◽  
Cheng Gong
Keyword(s):  
Real Time ◽  
Energy Optimization ◽  
Control Model ◽  
Random Disturbance ◽  
Chain Reactions ◽  
Metro Systems ◽  
Regenerative Energy ◽  
Shanghai Metro ◽  
Proper Solutions ◽  
Metro System

Automatic Train Systems (ATSs) have attracted much attention in recent years. A reliable ATS can reschedule timetables adaptively and rapidly whenever a possible disturbance breaks the original timetable. Most research focuses the timetable rescheduling problem on minimizing the overall delay for trains or passengers. Few have been focusing on how to minimize the energy consumption when disturbances happen. In this paper, a real-time timetable rescheduling method (RTTRM) for energy optimization of metro systems has been proposed. The proposed method takes little time to recalculate a new schedule and gives proper solutions for all trains in the network immediately after a random disturbance happens, which avoids possible chain reactions that would attenuate the reuse of regenerative energy. The real-time feature and self-adaptability of the method are attributed to the combinational use of Genetic Algorithm (GA) and Deep Neural Network (DNN). The decision system for proposing solutions, which contains multiple DNN cells with same structures, is trained by GA results. RTTRM is upon the foundation of three models for metro networks: a control model, a timetable model and an energy model. Several numerical examples tested on Shanghai Metro Line 1 (SML1) validate the energy saving effects and real-time features of the proposed method.

Vulnerability Analysis of Link-Weighted Shanghai Metrorail Transit Network

2018 ◽  
Author(s):  
Yanjie Zhang ◽  
Yalda Saadat ◽  
Dongming Zhang ◽  
Bilal M. Ayyub ◽  
Hongwei Huang
Keyword(s):  
Network Topology ◽  
Structural Features ◽  
Network Size ◽  
Global Network ◽  
Interval Length ◽  
Network Efficiency ◽  
Multiple Characteristic ◽  
Shanghai Metro ◽  
Metro System ◽  
Metro Network

With the degradation of metrorail facilities and the increase in network size, it is urgently needed to perform vulnerability assessment to ensure the safe operation of the metro system. In this paper, a link-weighted network model is proposed by considering the physical interval length between neighboring metro stations as link weight factor. Firstly, the metro network was essentially mapped into a bipartite topological diagram that consists of nodes denoting metro stations and links representing metro routes including any tunnels or bridges. After analyzing the network for its complexity level, it was revealed that the metro network topology can be appropriately constructed by using the Space L method. On this basis, multiple characteristic indexes of the network were calculated to characterize network topology structural features. We then tested the state of Shanghai metro network under different failure scenarios by removing a fraction of nodes from the network. Quantitative vulnerability analyses were conducted according to the change in the topological structure of Shanghai metro network and the change in the corresponding global network efficiency due to disruptions. Finally, both the network efficiency of link-weighted and unweighted Shanghai metro network topology were calculated and compared. This study has identified the vulnerable metro stations, which could provide support for the reasonable resource allocation of maintenance work and the decision-making in emergency treatment after failure. In order to increase the adaptability to emergencies and improve the operational efficiency, it was proposed that during the planning, construction, and operation of the metro system, the management and protection of the vulnerable stations should be given increased attention.

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