scholarly journals The Supermarket Model with Bounded Queue Lengths in Equilibrium

2018 ◽  
Vol 173 (3-4) ◽  
pp. 1149-1194
Author(s):  
Graham Brightwell ◽  
Marianne Fairthorne ◽  
Malwina J. Luczak
Keyword(s):  
Supermarket Model ◽  
Queue Lengths

scholarly journals Queue Length Forecasting in Complex Manufacturing Job Shops

Forecasting ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 322-338
Author(s):  
Marvin Carl May ◽  
Alexander Albers ◽  
Marc David Fischer ◽  
Florian Mayerhofer ◽  
Louis Schäfer ◽  
...  
Keyword(s):  
Operations Management ◽  
Queue Length ◽  
Manufacturing Systems ◽  
Production Control ◽  
Data Sets ◽  
Job Shops ◽  
Static Data ◽  
Queue Lengths ◽  
Operational Excellence

Currently, manufacturing is characterized by increasing complexity both on the technical and organizational levels. Thus, more complex and intelligent production control methods are developed in order to remain competitive and achieve operational excellence. Operations management described early on the influence among target metrics, such as queuing times, queue length, and production speed. However, accurate predictions of queue lengths have long been overlooked as a means to better understanding manufacturing systems. In order to provide queue length forecasts, this paper introduced a methodology to identify queue lengths in retrospect based on transitional data, as well as a comparison of easy-to-deploy machine learning-based queue forecasting models. Forecasting, based on static data sets, as well as time series models can be shown to be successfully applied in an exemplary semiconductor case study. The main findings concluded that accurate queue length prediction, even with minimal available data, is feasible by applying a variety of techniques, which can enable further research and predictions.

A Kalman Filter-Based Queue Length Estimation Method with Low-Penetration Mobile Sensor Data at Signalized Intersections

2018 ◽  
Vol 2672 (45) ◽  
pp. 253-264 ◽  
Author(s):  
Juyuan Yin ◽  
Jian Sun ◽  
Keshuang Tang
Keyword(s):  
Kalman Filter ◽  
Queue Length ◽  
Estimation Method ◽  
Mobile Internet ◽  
Internet Technology ◽  
Sensor Data ◽  
Linear Regression Method ◽  
Mobile Sensor ◽  
Length Estimation ◽  
Queue Lengths

Queue length estimation is of great importance for signal performance measures and signal optimization. With the development of connected vehicle technology and mobile internet technology, using mobile sensor data instead of fixed detector data to estimate queue length has become a significant research topic. This study proposes a queue length estimation method using low-penetration mobile sensor data as the only input. The proposed method is based on the combination of Kalman Filtering and shockwave theory. The critical points are identified from raw spatiotemporal points and allocated to different cycles for subsequent estimation. To apply the Kalman Filter, a state-space model with two state variables and the system noise determined by queue-forming acceleration is established, which can characterize the stochastic property of queue forming. The Kalman Filter with joining points as measurement input recursively estimates real-time queue lengths; on the other hand, queue-discharging waves are estimated with a line fitted to leaving points. By calculating the crossing point of the queue-forming wave and the queue-discharging wave of a cycle, the maximum queue length is also estimated. A case study with DiDi mobile sensor data and ground truth maximum queue lengths at Huanggang-Fuzhong intersection, Shenzhen, China, shows that the mean absolute percentage error is only 11.2%. Moreover, the sensitivity analysis shows that the proposed estimation method achieves much better performance than the classical linear regression method, especially in extremely low penetration rates.

scholarly journals Quantitative Analysis of Queue Length of Falah Roundabout (UAE, Sharjah)

2018 ◽  
Vol 3 (4) ◽  
pp. 6
Author(s):  
Emran Al Otaibi ◽  
Mohammed Refaei ◽  
Nadia Nassif ◽  
Anas Naqawa
Keyword(s):  
Queue Length ◽  
Factors Affecting ◽  
True Value ◽  
Data Regression ◽  
Field Data Collection ◽  
Term Paper ◽  
The Will ◽  
Queue Lengths ◽  
Rule Method ◽  
A Minor

Roundabouts have faced a huge development in terms of designing and operation, the reason behind that is to get the most safe and functional design. The functionality is affected by different factors e.g. line width, diameter of the roundabout etc., when the capacity of the roundabout is fully utilized, queue length starts to form in the different approaches, which indicates of a minor or major issue that should be studied. This paper discusses the different factors affecting the queue length of an approach on the roundabout (Al Falah roundabout), after obtaining the data, regression analysis was done to provide a model that can be used for estimating the volume capacity ratio from queue lengths or vice versa. Two other methods were used to compare the obtained model (HCM 2010 Method and Two Minute Rule Method), in addition to a field data collection of the actual timing needed to pass that queue length, which was assigned as the true value of the models and comparing depending on it. Finally, the discussion of the term paper, will include the different concepts of advanced statistical analysis, the will (as expected) contain different types of distributions and the coloration between the keys of the roundabouts design, and will study the limitation and how it can be improved in future.

Two-tier end-edge collaborative computation offloading for edge computing

2021 ◽  
pp. 1-12
Author(s):  
Yong Xiao ◽  
Ling Wei ◽  
Junhao Feng ◽  
Wang En
Keyword(s):  
Computing System ◽  
End Users ◽  
Edge Computing ◽  
Computation Offloading ◽  
Iot Applications ◽  
Delay Sensitive ◽  
Task Processing ◽  
Queue Lengths ◽  
The Stability ◽  
The Cost

Edge computing has emerged for meeting the ever-increasing computation demands from delay-sensitive Internet of Things (IoT) applications. However, the computing capability of an edge device, including a computing-enabled end user and an edge server, is insufficient to support massive amounts of tasks generated from IoT applications. In this paper, we aim to propose a two-tier end-edge collaborative computation offloading policy to support as much as possible computation-intensive tasks while making the edge computing system strongly stable. We formulate the two-tier end-edge collaborative offloading problem with the objective of minimizing the task processing and offloading cost constrained to the stability of queue lengths of end users and edge servers. We perform analysis of the Lyapunov drift-plus-penalty properties of the problem. Then, a cost-aware computation offloading (CACO) algorithm is proposed to find out optimal two-tier offloading decisions so as to minimize the cost while making the edge computing system stable. Our simulation results show that the proposed CACO outperforms the benchmarked algorithms, especially under various number of end users and edge servers.

Bosporus Bridge Toll Plaza in Istanbul, Turkey

2005 ◽  
Vol 1910 (1) ◽  
pp. 99-107
Author(s):  
Ismail Sahin ◽  
Güzin Akyıldız
Keyword(s):  
Traffic Management ◽  
Analysis Tool ◽  
Electronic Payment ◽  
Traffic Flows ◽  
Peak Period ◽  
Payment Methods ◽  
Queue Lengths ◽  
Flow Changes ◽  
Toll Plaza ◽  
Afternoon Peak

The Bosporus Bridge in Istanbul, Turkey, is the first of the two highway crossings connecting Asia and Europe over the Bosporus Strait. Drivers must pay their toll in the Europe-to-Asia direction at a toll plaza comprising 15 lanes. Manual and electronic payment methods are available in the plaza. The analysis of data showed that several factors affect both the throughput of the plaza and the traffic flows approaching it. Among the factors were whether a particular toll lane was in service, the contraflow lane operation toward the plaza, the lane operators’ performance, and the queue lengths in the plaza area. Rescaled cumulative vehicle count curves were used as the analysis tool. This allowed observation of (a) flow changes at particular points along the section of the highway studied and (b) propagation of the kinematic waves upstream of the plaza. The observations could be used for improving the performance of the plaza and for traffic management decisions associated with the afternoon peak period.

scholarly journals A Method for Queue Length Estimation in an Urban Street Network Based on Roll Time Occupancy Data

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Dongfang Ma ◽  
Dianhai Wang ◽  
Yiming Bie ◽  
Feng Sun ◽  
Sheng Jin
Keyword(s):  
Queue Length ◽  
Estimation Model ◽  
Link Length ◽  
Urban Street ◽  
City Street ◽  
Lane Width ◽  
Relation Model ◽  
Queue Lengths ◽  
Pass Through ◽  
The Relationship

A method estimating the queue length in city street networks was proposed using the data of roll time occupancy. The key idea of this paper is that when the queue length in front of the queue detector becomes longer, the speeds of the following vehicles to pass through the detector will become smaller, resulting in higher occupancy with constant traffic intensity. Considering the relationship between queue lengths and roll time occupancy affected by many factors, such as link length, lane width, lane number, and bus ratio, twelve different conditions were designed, and the traffic data under different conditions was obtained using VISSIM simulation. Based on the analysis of simulation data, an S-type logistic model was decided to develop for the relationship between queue lengths and roll time occupancy, and the fitting equations were obtained under the twelve simulation situations. The average model for the relationship between queue lengths and roll time occupancy was presented by successive multiple linear regression with the fitting equation parameters and simulation parameters, and the estimation model for queue length was presented through analyzing the equation of the average relation model.

scholarly journals M/G/∞ POLLING SYSTEMS WITH RANDOM VISIT TIMES

2007 ◽  
Vol 22 (1) ◽  
pp. 81-106 ◽  
Author(s):  
M. Vlasiou ◽  
U. Yechiali
Keyword(s):  
Service Time ◽  
Probability Generating Function ◽  
Expected Value ◽  
Polling Systems ◽  
Service Time Distribution ◽  
Polling System ◽  
Stieltjes Transform ◽  
Polling Model ◽  
Queue Lengths ◽  
Number Of Customers

We consider a polling system where a group of an infinite number of servers visits sequentially a set of queues. When visited, each queue is attended for a random time. Arrivals at each queue follow a Poisson process, and the service time of each individual customer is drawn from a general probability distribution function. Thus, each of the queues comprising the system is, in isolation, anM/G/∞-type queue. A job that is not completed during a visit will have a new service-time requirement sampled from the service-time distribution of the corresponding queue. To the best of our knowledge, this article is the first in which anM/G/∞-type polling system is analyzed. For this polling model, we derive the probability generating function and expected value of the queue lengths and the Laplace–Stieltjes transform and expected value of the sojourn time of a customer. Moreover, we identify the policy that maximizes the throughput of the system per cycle and conclude that under the Hamiltonian-tour approach, the optimal visiting order isindependentof the number of customers present at the various queues at the start of the cycle.

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