scholarly journals Improving the Capacity and Level of Service at the Sixth Circle in Jordan by Using Traffic Signals and Roundabout Metering Approach

2021 ◽  
Vol 15 (1) ◽  
pp. 69-80
Author(s):  
Ibrahim Khliefat ◽  
Mohammed Naser ◽  
Fadi Alhomaidat ◽  
Shadi Hanandeh
Keyword(s):  
Traffic Flow ◽  
Queue Length ◽  
Cycle Length ◽  
Heavy Traffic ◽  
Traffic Signals ◽  
Level Of Service ◽  
The Third ◽  
Cycle Lengths ◽  
C Program ◽  
Opening And Closing

Background and Objective: This study aims to improve the capacity and level of service at the sixth circle in Jordan by using traffic signals and a roundabout metering approach. Methods: VISSIM software and C++ program were used to improve the capacity and level of service. The site area (Sixth circle) was located near Crown Plaza and the Jordan Gate Towers project, which causes congestion due to heavy traffic flow. Therefore, this paper assesses the traffic in the sixth circle and presents the possible solutions to reduce the daily traffic flow for the users of this circle. Results: Four signals were placed at the roundabout in the second scenario, which was connected to each other with different cycle lengths. 90-second cycle length gives D value of the level of service. The third scenario was placed adaptive signals on the roundabout, which connects traffic signals with ground detectors placed at a certain distance before the signal and based on the queue length of the flow cars that pass the detector. Conclusion: The adaptive signals worked on the opening and closing and were designed according to the language simulation and the adoption of the language C++. The first two signals were opened considering the Swefieh road with the reference of King Faisal for a period of 45 seconds. It was then closed for 45 seconds to open the signal from the next street from the fifth circle with Zahran street.

Organization Optimization of Traffic Engineering in Urban CBD

2013 ◽  
Vol 579-580 ◽  
pp. 890-893
Author(s):  
Mei Mei Huang ◽  
Qing Yang ◽  
Shang Lin Xiao
Keyword(s):  
Traffic Flow ◽  
Traffic Engineering ◽  
Queue Length ◽  
Motor Vehicle ◽  
Heavy Traffic ◽  
Optimization Methods ◽  
Difficult Problem ◽  
Signal Timing ◽  
Total Capacity ◽  
Business District

Orderly organization of traffic engineering in the urban CBD (Center Business District) is a difficult problem, with crowding people flow, heavy traffic flow and complex surrounding situation. This paper set CBD along Xinhua Street in Jinhua city center as an example, focused on the organization optimization process of traffic engineering in CBD. Through the survey on traffic engineering status of sections and intersections, it analyzed road congestion characteristics and intersection signal timing with Vissim software emulation, proposed traffic optimization methods as road channelization, intersection signal timing adjustment of Xinhua-Liberation Road. In Xinhua Street section, it can effectively canalized traffic flow by broadening 2 two-way lanes, adding four pedestrian crossing refuges, and separating Motor vehicle and non-motor vehicle separation barrier. It took queue length, number of stops, delay time three indicators as the objective function with the application of Synchro software adjusting the intersection signal timing. As a result, the total queue length could be reduced from 708.5m to 586.6m and total capacity from 2041 pcu/ h to 2838 pcu/ h.

Estimating Pedestrian Impact on Coordination of Urban Corridors

2019 ◽  
Vol 2673 (7) ◽  
pp. 265-280 ◽  
Author(s):  
Sharmin-E-Shams Chowdhury ◽  
Aleksandar Stevanovic ◽  
Nikola Mitrovic
Keyword(s):  
Cycle Length ◽  
Network Performance ◽  
Traffic Signals ◽  
High Fidelity ◽  
Vehicular Traffic ◽  
Traffic Demand ◽  
Advantages And Disadvantages ◽  
Street Traffic ◽  
Pedestrian Impact ◽  
Signal Operations

Pedestrian walk timings at most U.S. traffic signals are run in concurrence with relevant signal phases for vehicular traffic. This usually means that signal operations coordinated for the major street can be interrupted by a pedestrian call. Such an interruption may in practice last for a few minutes, thus causing increased delays and stops for major traffic flows. An alternative to this design is to increase the cycle length and embed pedestrian timings within the ring-barrier structure of the prevailing coordination plan. Both approaches have advantages and disadvantages. A fresh approach offered by this study is a comprehensive experimental design and holistic performance evaluation perspectives. The study examines the two abovementioned treatments of pedestrian timings for a small corridor of five intersections in Utah. The experiments have been done in a high-fidelity microsimulation environment with the Software-in-the-Loop version of the field controller (Econolite ASC/3). Findings show that either approach works well for very low traffic demands. When the traffic demand increases findings cannot be generalized as they differ for major coordinated movements versus overall network performance. While major-street traffic prefers no interruption of the coordinated operations, the overall network performance is better in the other case. This can be explained by the fact that avoiding interruptions is usually achieved at the expense of longer cycle length, which increases delay for everyone in the network.

Impact of Turning Lane Storage Length and Turning Proportions on Throughput at Oversaturated Signalized Intersections

2021 ◽  
pp. 036119812110171
Author(s):  
A. M. Tahsin Emtenan ◽  
Christopher M. Day
Keyword(s):  
Flow Rate ◽  
Cycle Length ◽  
Signal Timing ◽  
Real World Data ◽  
Left Turn ◽  
Common Response ◽  
Cycle Lengths ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
Timing Strategies

During oversaturated conditions, common objectives of signal timing are to maximize vehicle throughput and manage queues. A common response to increases in vehicle volumes is to increase the cycle length. Because the clearance intervals are displayed less frequently with longer cycle lengths and fewer cycles, more of the total time is used for green indications, which implies that the signal timing is more efficient. However, previous studies have shown that throughput reaches a peak at a moderate cycle length and extending the cycle length beyond this actually decreases the total throughput. Part of the reason for this is that spillback caused by the turning traffic may cause starvation of the through lanes resulting in a reduction of the saturation flow rate within each lane. Gaps created by the turning traffic after a lane change may also reduce the saturation flow rate. There is a relationship between the proportions of turning traffic, the storage length of turning lanes, and the total throughput that can be achieved on an approach for a given cycle length and green time. This study seeks to explore this relationship to yield better signal timing strategies for oversaturated operations. A microsimulation model of an oversaturated left-turn movement with varying storage lengths and turning proportions is used to determine these relationships and establish a mathematical model of throughput as a function of the duration of green, storage length, and turning proportion. The model outcomes are compared against real-world data.

Heavy traffic queue length scaling in switches with reconfiguration delay

2021 ◽  
Author(s):  
Chang-Heng Wang ◽  
Siva Theja Maguluri ◽  
Tara Javidi
Keyword(s):  
Queue Length ◽  
Heavy Traffic ◽  
Length Scaling

Modelling the egg components and internal cycle length of laying hens

2019 ◽  
Vol 59 (3) ◽  
pp. 420 ◽  
Author(s):  
H. C. P. Bendezu ◽  
N. K. Sakomura ◽  
E. B. Malheiros ◽  
R. M. Gous ◽  
N. T. Ferreira ◽  
...  
Keyword(s):  
Cycle Length ◽  
Egg Production ◽  
Laying Hens ◽  
Experimental Period ◽  
Experimental Unit ◽  
Egg Weight ◽  
Cycle Lengths ◽  
Predicted Values ◽  
Egg Components ◽  
Over Time

A model that can estimate the changes that occur to the composition of egg components over time is an important tool for the nutritionists, since it can provide information about the nutrients required by a laying hen to achieve her potential egg output. In this context, the present study was aimed to model the potential egg production of laying hens during the egg-production period. One hundred and twenty Hy-Line W36 and ISA-Brown layers were used from 18 to 60 weeks of age, with each bird being an experimental unit. The birds were housed in individual cages during the experimental period. Egg production (%), egg weight (g) and the weight of egg components were recorded for each bird. The data were used to calculate the parameters of equations for predicting the weights of yolk, albumen and shell, and for predicting internal cycle length. The predicted results were evaluated by regressing residual (observed minus predicted) values of the predicted values centred of their average value. The equations for predicting mean yolk weight with age are for Hy-Line W36 (y1) and ISA-Brown (y2) respectively. Albumen and shell weights for Hy-Line W36 were described by the equations 15.07 × (yolk weight)0.37 and 0.70 × (yolk + albumen weight)0.50 respectively, and for ISA-Brown, 21.99 × (yolk weight)0.24 and 1.60 × (yolk + albumen weight)0.34 respectively. The average internal cycle length over time for Hy-Line W36 (ICL1) is described by the model 22.95 + 5.24 × (0.962t) + 0.02 × t and for ISA-Brown by 24.01 + 10.29 × (0.94t) + 0.004 × t, where t is the age at first egg (days). The assessment of the results indicated that the equations for predicting egg weight were more accurate for Hy-Line W36 but less precise for both strains, whereas the equation models for predicting the internal cycle lengths were more accurate and precise for ISA-Browns. The models could predict the potential weight of egg components and the rate of laying associated with the internal cycle lengths, and, on the basis of this information, it is possible to improve the nutrient requirement estimated.

scholarly journals A Simple Porcine Model of Inducible Sustained Atrial Fibrillation

2016 ◽  
Vol 11 (1) ◽  
pp. 76-78 ◽  
Author(s):  
Anson M. Lee ◽  
Jacob R. Miller ◽  
Rochus K. Voeller ◽  
Andreas Zierer ◽  
Shelly C. Lall ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Animal Model ◽  
Cycle Length ◽  
Porcine Model ◽  
New Technologies ◽  
Median Sternotomy ◽  
Manual Stimulation ◽  
History Of ◽  
Cycle Lengths ◽  
Rapid Pacing

The surgical management of atrial fibrillation (AF) is an evolving field with a history of testing various lesion sets and ablation technologies. Previous animal models of AF require a chronic intervention to make AF reliably inducible. Our objective was to create an acute, reliable, and reproducible porcine model of sustained AF. To accomplish this, 21 adult domestic pigs underwent median sternotomy. Methods to induce AF were then performed sequentially: manual stimulation, rapid pacing (200 beats per minute), and then rapid pacing of 8 beats with a cycle length of 300 milliseconds, followed by an extra stimulus at decreasing cycle lengths. If AF was not induced, burst pacing was performed at a cycle length of 90 milliseconds for 30 seconds. If AF was still not induced, intravenous neostigmine was administered, and the process was repeated. Atrial fibrillation was considered sustained after 1 minute. Attempts at AF induction were successful in 18 (86%) of 21. Atrial fibrillation was induced during manual stimulation in four (19%), during rapid pacing in five (24%), during burst pacing in five (24%), and after the administration of neostigmine in four (19%). Mean (SD) duration of AF was 3.6 (2.6) minutes. Of the 18, 14 (78%) reverted to sinus rhythm spontaneously and 4 (22%) required an antiarrhythmic. This technique of inducing AF can easily be used to evaluate new technologies and lesion sets without the need for creating a chronic animal model.

A Traffic Capacity Model of Lane Occupation

2014 ◽  
Vol 599-601 ◽  
pp. 2083-2087
Author(s):  
Yi Xuan He
Keyword(s):  
Traffic Flow ◽  
Queue Length ◽  
Production Condition ◽  
Modern Society ◽  
Traffic Jam ◽  
Traffic Flow Theory ◽  
Related Data ◽  
Traffic Capacity ◽  
Capacity Model ◽  
Big City

In modern society, traffic jam has already become a major problem which curbs the development of big city. And lane occupation is an important reason why traffic jam happens. After studying on the production condition, time and queue length of traffic jam after lane occupation happens, we propose a model based on famous traffic flow theory and we use related data to verify the rightness of our model. Result shows that our model can predict the development of traffic jam caused by lane occupation

Demonstration of hysteresis in refractoriness of canine ventricular myocardium

1988 ◽  
Vol 255 (6) ◽  
pp. H1342-H1348
Author(s):  
C. Giorgi ◽  
M. Vermeulen ◽  
R. Cardinal ◽  
P. Savard ◽  
R. Nadeau ◽  
...  
Keyword(s):  
Pulse Width ◽  
Cycle Length ◽  
Ventricular Myocardium ◽  
Ventricular Muscle ◽  
Cycle Lengths ◽  
Long Pulse ◽  
Basic Cycle Length ◽  
Canine Ventricular Myocardium

The properties and determinants of hysteresis during ventricular effective refractory period (VERP) measurements by an extrastimulus technique were determined in 15 anesthetized open-chest dogs as well as in isolated ventricular muscle (n = 6). VERP was determined both by decreasing the S1-S2 interval and also by increasing S1S2. Hysteresis was then calculated by subtracting the VERP obtained with the decreasing S1S2 from the VERP obtained with the increasing S1S2. The effects of basic cycle length, pulse width, stimulation intensity, and the number of basic drives on VERP and hysteresis were evaluated. VERP was shorter for long pulse width, high stimulation intensities, and shorter basic cycle lengths. These modifications were not associated with significant changes of hysteresis. VERP was shorter during decreasing S1S2 than during increasing S1S2. Hysteresis was greater with 6 basic drive cycles than with 12 (P less than 0.001) in both in vivo and in vitro preparations. The data suggest that 1) hysteresis occurs during VERP measurements; 2) hysteresis is independent of stimulation modality; and 3) hysteresis decreases with the number of basic drive cycles.

scholarly journals Pathwise optimality of the exponential scheduling rule for wireless channels

2004 ◽  
Vol 36 (04) ◽  
pp. 1021-1045 ◽  
Author(s):  
Sanjay Shakkottai ◽  
R. Srikant ◽  
Alexander L. Stolyar
Keyword(s):  
Queue Length ◽  
Wireless Channels ◽  
Unique Feature ◽  
Heavy Traffic ◽  
Wireless Channel ◽  
Service Rate ◽  
Resource Pooling ◽  
Scheduling Policy ◽  
Multiple Data ◽  
Heavy Traffic Limit

We consider the problem of scheduling the transmissions of multiple data users (flows) sharing the same wireless channel (server). The unique feature of this problem is the fact that the capacity (service rate) of the channel varies randomly with time and asynchronously for different users. We study a scheduling policy called the exponential scheduling rule, which was introduced in an earlier paper. Given a system withNusers, and any set of positive numbers {an},n= 1, 2,…,N, we show that in a heavy-traffic limit, under a nonrestrictive ‘complete resource pooling’ condition, this algorithm has the property that, for each timet, it (asymptotically) minimizes maxnanq̃n(t), whereq̃n(t) is the queue length of usernin the heavy-traffic regime.

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