scholarly journals Managing Recurrent Congestion of Subway Network in Peak Hours with Station Inflow Control

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Qingru Zou ◽  
Xiangming Yao ◽  
Peng Zhao ◽  
Fei Dou ◽  
Taoyuan Yang
Keyword(s):  
Large Scale ◽  
Practical Applications ◽  
C Programming Language ◽  
Passenger Flow ◽  
Assignment Model ◽  
C Programming ◽  
Subway System ◽  
And Control ◽  
Internal Relationship

Station inflow control (SIC) is an important and effective method for reducing recurrent congestion during peak hours in the Beijing, Shanghai, and Guangzhou subway systems. This work proposes a practical and efficient method for establishing a static SIC scheme in normal weekdays for large-scale subway networks. First, a traffic assignment model without capacity constraint is utilized to determine passenger flow distributions on the network. An internal relationship between station inflows and section flows is then constructed. Second, capacity bottlenecks are identified by considering the transport capacity of each section. Then, a feedback-based bottleneck elimination strategy is established to search target control stations and determine their control time and control strength. To validate the effectiveness of the proposed approach, a decision support system coded in the C# programming language was developed, and the Beijing subway was used as a case study. The results indicate that the proposed method and tool are capable of practical applications, and the generated SIC plan has better performance over the existing SIC plan. This study provides a practical and useful method for operation agencies to construct SIC schemes in the subway system.

The Big-headed Ant Pheidole megacephala: a new threat to monsoonal northwestern Australia

1998 ◽  
Vol 4 (3) ◽  
pp. 250 ◽  
Author(s):  
Benjamin D. Hoffmann
Keyword(s):  
Agricultural Production ◽  
Large Scale ◽  
Foraging Ecology ◽  
Potential Threat ◽  
Pheidole Megacephala ◽  
Realistic Option ◽  
Northwestern Australia ◽  
Nature Park ◽  
And Control

The Big-headed Ant Pheidole megacephala is a major threat to native invertebrate assemblages and to agricultural production world-wide. This paper reviews its known biology including its foraging ecology, colony founding and dispersal behaviour. A case study is presented to illustrate its potential conservation significance for northern Australia. At Howard Springs Nature Park in the Darwin region of the Northern Territory, an infestation of P. megacephala was found to cover 25 ha and is continuing to spread, with its distribution centred on a rainforest patch. The abundance of P. megacephala within the rainforest was 37?110 times that of total native ant abundance at uninfested sites. Only two individuals of a single native ant species were found in the highest abundance of P. megacephala and abundance of other invertebrates was only 15% of natural levels. Pheidole megacephala is a serious potential threat to native biodiversity in monsoonal Australia. Successful eradication on a large scale is a realistic option and control methods are discussed, including chemicals and fire.

scholarly journals Monte Carlo Simulation Experiments for Engineering Optimisation

2015 ◽  
Vol 2 (1) ◽  
pp. 97
Author(s):  
Robert Anderson ◽  
Zhou Wei ◽  
Ian Cox ◽  
Malcolm Moore ◽  
Florence Kussener
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Tolerance Analysis ◽  
Simulation Experiments ◽  
Practical Applications ◽  
Study Approach ◽  
Good Set ◽  
Robust Process ◽  
And Control

Design of Experiments (DoE) is widely used in design, manufacturing and quality management. The resulting data is usually analysed with multiple linear regression to generate polynomial equations that describe the relationship between process inputs and outputs. These equations enable us to understand how input values affect the predicted value of one or more outputs and find good set points for the inputs. However, to develop robust manufacturing processes, we also need to understand how variation in these inputs appears as variation in the output. This understanding allows us to define set points and control tolerances for the inputs that will keep the outputs within their required specification windows. Tolerance analysis provides a powerful way of finding input settings and ranges that minimise output variation to produce a process that is robust. In many practical applications, tolerance analysis exploits Monte Carlo simulation of the polynomial model generated from DoE’s. This paper briefly describes tolerance analysis and then shows how Monte Carlo simulation experiments using space-filling designs can be used to find the input settings that result in a robust process. Using this approach, engineers can quickly and easily identify the key inputs responsible for transferring undesired variation to their process outputs and identify the set points and ranges that make their process as robust as possible. If the process is not sufficiently robust, they can rationally investigate different strategies to improve it. A case study approach is used to aid explanation and understanding.

scholarly journals Thermofluid Modelling of Large-Scale Orchards for Optimal Design and Control of Active Frost Prevention Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 378
Author(s):  
Ercan Atam ◽  
Se-Woon Hong ◽  
Alessia Arteconi
Keyword(s):  
Optimal Design ◽  
Control Systems ◽  
Large Scale ◽  
Initial Conditions ◽  
Minimum Energy ◽  
Prunus Armeniaca ◽  
Thermal Dynamics ◽  
Heating Systems ◽  
And Control

Accurate modelling and simulation of temperature dynamics in large-scale orchards is important in many aspects, including: (i) for the calculation of minimum energy required to be used in optimal design of active frost prevention energy systems (fully renewable or partially renewable) to prevent freezing of fruit flowers, buds, or leaves; (ii) for testing frost prevention control systems before real-implementation which regulate active heating systems inside orchards targeted to prevent frost. To that end, in this study, first, a novel and sophisticated parametric computational thermofluid dynamics (CTFD) model for orchard air thermal dynamics for different orchard parameters (such as fruit type, climate, number of trees, their sizes, and distance between them) and boundary/initial conditions was developed and validated with field data from the literature. Next, the use of the developed parametric CTFD model was demonstrated through a case study to calculate the minimal thermal energy required to prevent frost under different frost levels in a test Prunus armeniaca orchard located in Malatya, Turkey, which is the world capital for dry apricot production.

Distributed Cross-Direction Control System Based on CAN-Bus

2014 ◽  
Vol 705 ◽  
pp. 345-349
Author(s):  
Xian Cheng Shi ◽  
Yu Cheng Feng ◽  
Jin Song Zeng ◽  
Ke Fu Chen
Keyword(s):  
Control System ◽  
Large Scale ◽  
Can Bus ◽  
Monitoring Station ◽  
Paper Machine ◽  
Practical Applications ◽  
Cross Direction ◽  
Direction Control ◽  
Opc Technology ◽  
And Control

A distributed cross-direction control system based on CAN-bus was designed to solve the large-scale cross-direction control problem for paper machine. Multiple Master-Slave CAN networks were constructed in parallel to coordinate and control multiple array actuators, and the Ethernet/CAN converter was used to connect the monitoring station with the field intelligent actuators. The monitoring station accesses measured data and field data via OPC technology. A CAN application layer protocol and corresponding underlying communication software were designed according to the characteristics of the cross-direction control processes. Finally, the feasibility and reliability of the system were verified with practical applications.

Reactive tracers reveal hydraulic and control instabilities in full-scale activated sludge plant

2008 ◽  
Vol 57 (7) ◽  
pp. 1001-1007 ◽  
Author(s):  
D. Braun ◽  
W. Gujer
Keyword(s):  
Large Scale ◽  
Oxygen Sensor ◽  
Electrochemical Sensors ◽  
Aeration Tank ◽  
Control Loop ◽  
Reactive Tracers ◽  
And Control ◽  
Present Case Study ◽  
Aeration Control

The hydraulic characteristics of aeration tanks in WWTPs have a major impact on the degradation of pollutants, as well as on the control of the aeration. In particular in long reactors, which are not separated by baffles, hydraulic shortcuts or large scale recirculation can lead to a loss of performance. This work demonstrates that reactive tracers such as ammonium and oxygen can be used to investigate the hydraulics of aeration tanks in detail. With the use of electrochemical sensors it is possible to investigate effects in a broad range of time scales. In the present case study a slow oscillation of the aeration control loop was investigated. Large scale recirculation in the aeration tank and fast fluctuations of the ammonium concentrations close to the oxygen sensor were identified as the cause of these oscillations. Both, the recirculation as well as the fluctuation of the ammonium have a substantial influence on the performance of the aeration tank and the aeration control loop.

scholarly journals Power monitoring and control for large scale projects: SKA, a case study

2016 ◽  
Author(s):  
Domingos Barbosa ◽  
João Paulo Barraca ◽  
Dalmiro Maia ◽  
Bruno Carvalho ◽  
Jorge Vieira ◽  
...  
Keyword(s):  
Large Scale ◽  
Monitoring And Control ◽  
Power Monitoring ◽  
And Control

scholarly journals Performance comparison of asymmetric cryptography (case study-mail message)

2020 ◽  
Vol 4 (3) ◽  
pp. 105-111
Author(s):  
Zarni Sann ◽  
Thi Thi Soe ◽  
Kaythi Wyut Mhone Knin ◽  
Zin May Win
Keyword(s):  
Data Encryption ◽  
Performance Comparison ◽  
C Programming Language ◽  
Cpu Time ◽  
Asymmetric Cryptography ◽  
Mail Server ◽  
C Programming ◽  
Elgamal Encryption ◽  
Server System

Data encryption is well known as essential for today’s technology. ElGamal encryption and RSA algorithmis made before storing mails to mail server. ElGamal decryption and RSA decryption is made after retrieving mailsfrom mail server. This system is implemented to secure mail server system for local government’s important mailmessages. These algorithms consume a considerable amount of time and resources of memory, CPU time, andcomputation time to encrypt and decrypt data. This paper discuss the results comparison of these algorithms in termof encryption time, decryption time, and memory usage over variable file sizes. The results show that RSA does fasterencryption process in compare with ElGamal. However, ElGamal decryption process is quicker than RSA. This systemis also expressed comparison of storage Size between RSA and ElGamal. Both of these algorithms are cryptographicpublic-key algorithms but have roles in different techniques. This system is using C# programming language and SQLServer to store mail messages.

scholarly journals A decomposition algorithm of Petri net utilizing index function

Filomat ◽  
2020 ◽  
Vol 34 (15) ◽  
pp. 5085-5094
Author(s):  
Kai-Qing Zhou ◽  
Li-Ping Mo ◽  
Chang-Feng Chen ◽  
Wei Jiang
Keyword(s):  
Petri Net ◽  
Large Scale ◽  
Dynamic Properties ◽  
Decomposition Algorithm ◽  
State Explosion ◽  
Decomposition Approach ◽  
Index Function ◽  
Knowledge Based ◽  
And Control

Recently, it is difficult to simulate, analyze and control a real knowledge-based system using the correspondence Petri net (PN) when there exist many current states. To overcome the state explosion problem of PN, an efficient decomposition algorithm is presented to divide a large-scale PN into a series of corresponding sub-PNs by keeping the consistency of dynamic properties. In this novel decomposition approach, an index function is defined to judge the subnet needs to be decomposed or not. Furthermore, an exhaustive analysis on the consistency of related dynamic properties is also discussed between the original PN and the corresponding sub-PNs. Finally, a case study is carried out to illustrate the feasibility and validity of the proposed approach.

scholarly journals Into the thirteenth Month: A Case Study on the Outbreak Analytics and Modeling the spread of SARS-CoV-2 Infection in Pune City, India

2021 ◽  
Author(s):  
Joy Monteiro ◽  
Bhalchandra Pujari ◽  
Sarika Maitra Bhattacharrya ◽  
Anu Raghunathan ◽  
Ashwini Keskar ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Information Dissemination ◽  
Public Access ◽  
Accurate Information ◽  
Time Data ◽  
Outbreak Response ◽  
First Case ◽  
And Control

With more than 140 million people infected globally and 3 million deaths, the COVID 19 pandemic has left a lasting impact. A modern response to a pandemic of such proportions needs to focus on exploiting all available data to inform the response in real-time and allow evidence-based decision-making. The intermittent lockdowns in the last 13 months have created economic adversity to prevent anticipated large-scale mortality and relax the lockdowns have been an attempt at recovering and balancing economic needs and public health realities. This article is a comprehensive case study of the outbreak in the city limits of Pune, Maharashtra, India, to understand the evolution of the disease and transmission dynamics starting from the first case on March 9, 2020. A unique collaborative effort between the Pune Municipal Corporation (PMC), a government entity, and the Pune knowledge Cluster (PKC) allowed us to layout a context for outbreak response and intervention. We report here how access to granular data for a metropolitan city with pockets of very high-density populations will help analyze, in real-time, the dynamics of the pandemic and forecasts for better management and control of SARS-CoV-2. Outbreak data analytics resulted in a real-time data visualization dashboard for accurate information dissemination for public access on the epidemic's progress. As government agencies craft testing and vaccination policies and implement intervention strategies to mitigate a second wave, our case study underscores the criticality of data quality and analytics to decode community transmission of COVID-19.

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