scholarly journals A Paradox of the Average Waiting Time for the Case of a Single Bottleneck on the Commuters’ Route

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hakan Özaktaş ◽  
Nureddin Kırkavak ◽  
Ayşe Nilay Alpay
Keyword(s):  
Waiting Time ◽  
Performance Indicators ◽  
Random Variable ◽  
Interarrival Time ◽  
Deterministic Case ◽  
Exponential Distributions ◽  
Average Waiting Time ◽  
Statistical Verification ◽  
Basic Performance ◽  
Interarrival Times

Average waiting time is considered as one of the basic performance indicators for a bottleneck zone on a route for commuter traffic. It turns out that the average waiting time in a queue remains paradoxically unchanged regardless of how fast the queue dissolves for a single bottleneck problem. In this study, the paradox is verified theoretically for the deterministic case with constant arrival and departure rates. Consistent results with the deterministic case have also been obtained by simulation runs for which vehicle interarrival time is a random variable. Results are tabulated for interarrival times which have uniform, triangular, normal, and exponential distributions along with a statistical verification of the average waiting time paradox.

AN ANALYSES ON PATIENTS’ QUEUING SYSTEM AT MUHAMMAD ABDULLAHI WASE SPECIALIST HOSPITAL, KANO

2021 ◽  
Vol 5 (2) ◽  
pp. 344-350
Author(s):  
Yunusa Ojirobe ◽  
Abubakar Yahaya ◽  
Muhammad Abdulkarim
Keyword(s):  
Waiting Time ◽  
Performance Indicators ◽  
Goodness Of Fit ◽  
Primary Data ◽  
Single Server ◽  
Utilization Factor ◽  
Average Waiting Time ◽  
Number Of Patients ◽  
Multi Server ◽  
System Average

A major cause for concern in hospitals is congestion, which brings about untoward hardship to patients due to long queues and delay in service delivery. This paper seeks to minimize the waiting time of patients by comparing the performance indicators of a single server and multi-server model at the Paediatrics Department of Muhammad Abdullahi Wase Specialist Hospital Kano (MAWSHK). In order to achieve this, primary data was obtained through direct observation which in turn is subjected to the test of goodness of fit to ascertain the distribution that best describes the data. The performance indicators comprising utilization factor, average number of patients in the queue, average number of patients in the system, average waiting time in queue and average waiting time in system for a single server and multi-server model were computed and analyzed respectively. Our findings indicate that the G/G/4 model performs better compared to the G/G/1 model as it minimizes the waiting time of patients

On Queues with Interarrival Times Proportional to Service Times

1996 ◽  
Vol 10 (1) ◽  
pp. 87-107 ◽  
Author(s):  
Israel Cidon ◽  
Roch Guréin ◽  
Asad Khamisy ◽  
Moshe Sidi
Keyword(s):  
Waiting Time ◽  
Service Time ◽  
Queueing Systems ◽  
Random Variable ◽  
Interarrival Time ◽  
Time Interval ◽  
Equivalent System ◽  
Stieltjes Transform ◽  
Switched Networks ◽  
Associated Solutions

We analyze a family of queueing systems where the interarrival time In+1 between customers n and n + 1 depends on the service time Bn of customer n. Specifically, we consider cases where the dependency between In+1 and Bn is a proportionality relation and Bn is an exponentially distributed random variable. Such dependencies arise in the context of packet-switched networks that use rate policing functions to regulate the amount of data that can arrive to a link within any given time interval. These controls result in significant dependencies between the amount of work brought in by customers/packets and the time between successive customers. The models developed in the paper and the associated solutions are, however, of independent interest and are potentially applicable to other environments.Several scenarios that consist of adding an independent random variable to the interarrival time, allowing the proportionality to be random and the combination of the two are considered. In all cases, we provide expressions for the Laplace-Stieltjes Transform of the waiting time of a customer in the system. Numerical results are provided and compared to those of an equivalent system without dependencies.

SET-VALUED PERFORMANCE APPROXIMATIONS FOR THE QUEUE GIVEN PARTIAL INFORMATION

2020 ◽  
pp. 1-23
Author(s):  
Yan Chen ◽  
Ward Whitt
Keyword(s):  
Steady State ◽  
Decay Rate ◽  
Waiting Time ◽  
Partial Information ◽  
Upper And Lower Bounds ◽  
Interarrival Time ◽  
Limited Information ◽  
Wide Range ◽  
The Mean ◽  
Third Moment

In order to understand queueing performance given only partial information about the model, we propose determining intervals of likely values of performance measures given that limited information. We illustrate this approach for the mean steady-state waiting time in the $GI/GI/K$ queue. We start by specifying the first two moments of the interarrival-time and service-time distributions, and then consider additional information about these underlying distributions, in particular, a third moment and a Laplace transform value. As a theoretical basis, we apply extremal models yielding tight upper and lower bounds on the asymptotic decay rate of the steady-state waiting-time tail probability. We illustrate by constructing the theoretically justified intervals of values for the decay rate and the associated heuristically determined interval of values for the mean waiting times. Without extra information, the extremal models involve two-point distributions, which yield a wide range for the mean. Adding constraints on the third moment and a transform value produces three-point extremal distributions, which significantly reduce the range, producing practical levels of accuracy.

scholarly journals The assessment of target value of performance indicators of small and medium-sized companies’ financial management with industry and regional environmental features

2019 ◽  
Vol 81 (2) ◽  
pp. 290-300 ◽  
Author(s):  
N. N. Muraveva ◽  
N. S. Talalaeva
Keyword(s):  
Performance Indicators ◽  
Financial Management ◽  
Medium Size ◽  
Small Range ◽  
Economic Agents ◽  
Environmental Features ◽  
Target Values ◽  
Basic Performance ◽  
Long Time ◽  
Standard Values

The efficient financial management in profit organizations are the getting their specific values of basic performance indicators (efficiency criteria), which characterize the solvability, financial capability, profitability of the economic agents. It’s not correct to use standard values estimating the efficiency of small and medium-sized companies’ financial management, being that such enterprises carry on business in the specific industry (there are not the diversification of business) in one specific region, having a small range of activity and sales. This determines the fundamental inequality conditions and objective preconditions their business, being reflected in financial status and results. The research takes into consideration the industry and regional environmental features, using the financial data reporting of profit-making small and medium-size enterprises of the Volgograd Region, which do business in distributive trade, manufacture, building and construction sector. Logics of research based on reference approach to estimate the efficiency of financial management: the values of basic performance indicators of enterprise getting profit a long time in spite of changing in the region’s economic climate, should be taken as the target values corresponding to efficient financial management. Based on research numerical values of industry-specific performance indicators were got. Those indicators are not equal to standard values. The target level of financial indicators serves as a guidemark for small and medium-sized companies to get the efficient financial management and be reaching profitability.

scholarly journals Super Smart Optimized Round Robin

2016 ◽  
Vol 2 (2) ◽  
pp. 19-21
Author(s):  
Achmad Teguh Wibowo
Keyword(s):  
Waiting Time ◽  
Turnaround Time ◽  
Round Robin ◽  
Priority Scheduling ◽  
Average Waiting Time ◽  
First Come First Serve ◽  
Time Average ◽  
Average Turnaround Time

Aspek penting dalam sistem operasi adalah multiprogramming. Multiprogramming adalah proses atau metode yang digunakan untuk mengekssekusi beberapa proses secara bersamaan dalam memori. Tujuan utamanya adalah untuk meminimalkan Average Waiting Time, Average Turnaround Time, dan memaksimalkan penggunaan CPU. Ada berbagai algoritma yang digunakan dalam multiprogramming seperti First Come First Serve (FCFS), Shortest Job First (SJF), Priority Scheduling (PS) dan Round Robin(RR). Diantara semua itu yang paling sering digunakan adalah Round Robin. Round Robin merupakan algoritma penjadwalan yang optimal dengn sistem timeshared. Dalam RR, waktu kuantum bersifat statis dan algoritma ini bergantung pada besarnya kuantum yang dipilih/digunakan. Kuantum inilah yang berpengaruh pada Average Waiting Time dan Average Turnaround Time nantinya. Tujuan dari makalah ini adalah mengusulkan algoritma yang lebih baik daripada Round Robin sederhana dan Smart Optimized Round Robin sebelumnya.

scholarly journals Inter-Machine Exchange of Real Time in Distributed Computer Systems

2020 ◽  
pp. short50-1-short50-8
Author(s):  
Vladimir Bogatyrev ◽  
Stanislav Bogatyrev ◽  
Anatoly Bogatyrev
Keyword(s):  
Real Time ◽  
Analytical Model ◽  
Waiting Time ◽  
Computer Systems ◽  
Delivery Time ◽  
Network Nodes ◽  
Average Waiting Time ◽  
Service Delays ◽  
Distributed Computer Systems

The possibilities of increasing the likelihood of timely service and reducing the average waiting time for requests for inter-machine exchange in distributed real-time computer systems are investigated. The analyzed effect is achieved as a result of redundant multi-way transmissions of packets that are critical to delays, which provide for the replication of transmitted packets with the task for each replica of the path (route) of the sequential passage of network nodes. The condition for the timeliness of the reserved transmissions is that the accumulated waiting in the queues of the nodes making up the path, at least for one of the replicas, does not exceed the maximum permissible time. An analytical model is proposed for estimating the average delays of multi-path redundant transmissions, when determined by the average delivery time of the first of the replicas transmitted in different ways. For requests critical to service delays, the influence of the frequency of reservation (replication) of requests on the probability of their timely service and the average waiting time accumulated at the nodes of the path for the replica delivered first was analyzed.

scholarly journals Scheduling Schemes in Dynamic Multilevel Packet Scheduling in WSN

2019 ◽  
Vol 8 (2) ◽  
pp. 3800-3804
Keyword(s):  
Real Time ◽  
Waiting Time ◽  
Packet Scheduling ◽  
Turnaround Time ◽  
Priority Level ◽  
Average Waiting Time ◽  
Level 3 ◽  
Overall Performance ◽  
The Individual ◽  
Priority Levels

As focusing on the scheduling schemes, there are many scheduling schemes for multilevel. So the paper is concentrating to compare the scheduling schemes and producing the average waiting time and turnaround time. If it is minimized then the overall performance may shoot up. In this paper comparison is done between three scheduling schemes Enhanced Dynamic Multilevel Packet scheduling (EDMP), Circular Wait Dynamic Multilevel Packet scheduling (CW-DMP) and Starvation-Free Dynamic Multilevel Packet scheduling (SF-DMP). In all the above schemes there are three priority levels say priority level 1(Pr1), priority level 2(Pr2) and priority level 3(Pr3). Pr1 will comprise the real time tasks, Pr2 containing the non real time remote tasks and non real time local tasks are there in Pr3. In each and every scheme, each and every priority level will be using the individual scheduling technique to schedule the tasks. Also the comparison is done based on waiting time and the turnaround time of the task thereby the average waiting time and the average turnaround time are calculated.

scholarly journals EP.WE.727Upper GI Surgery Clinic Referrals; Can We Improve the Patient Experience?

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Mohamed Abouelazayem ◽  
Raluca Belchita
Keyword(s):  
Patient Experience ◽  
Waiting Time ◽  
Waiting Times ◽  
Patient Records ◽  
Electronic Patient Records ◽  
Post Discharge ◽  
Average Waiting Time ◽  
Upper Gi

Abstract Aim To review the new referrals to the Upper GI surgery clinic for appropriateness, investigations requested, and waiting times and to identify potential pathways to reduce waiting times and improve the patient experience. Method Patients who attended the UGI clinic over 2 months period were identified. Data were collected from GP referrals and Electronic Patient Records. Follow up, post-discharge appointments, and Did Not Attends were excluded. Data collected included time from referral to first clinic, symptoms, investigations requested, suitability for a pathway, and appropriateness of referral. A first clinic outcome was concluded from reading the GP referral, there were 5 outcomes to choose from; direct to another specialty, discharge back to GP, clinic, surgery, pre-investigate and clinic. Results 147 referrals were analysed. The average waiting time from referral to the first clinic was 51 days (range 7-119 days). 73% of the referrals were GP referrals and 27% from other specialties. The most common referral was for gallstones and the most common 2 outcomes were Pre-investigate and surgery. Conclusion Most of the investigations and outcomes suggested from the project were the same as those from clinic letters. The following pathways can be developed to cut waiting times and costs for the trust:

The Study on Production Performances of Part Transporter in Flexible Manufacturing System by Using Simulation Method

2012 ◽  
Vol 576 ◽  
pp. 714-717
Author(s):  
Mohammad Iqbal ◽  
Muhammad Ridwan Andi Purnomo ◽  
Muhammad Ammar Bin Mohd Imra ◽  
Mohamed Konneh ◽  
A.N. Mustafizul Karim
Keyword(s):  
Waiting Time ◽  
Flexible Manufacturing ◽  
Material Handling ◽  
Manufacturing System ◽  
Flexible Manufacturing System ◽  
Arrival Rate ◽  
Simulation Method ◽  
Simulation Software ◽  
Average Waiting Time ◽  
Processing Times

Material handling is one of major components in Flexible Manufacturing System (FMS). Any improvement of material handling capability is to affect the performance of the whole system. This paper discusses the simulation study on the effect of part arrival rate and dispatching rules to the average waiting time and production rate of the FMS. The facilities of the system were modeled into simulation environment by using Arena Simulation Software. The production parameters such as machine processing times, part transportation speed and type of products were put into the model to represent the behaviors of the real system. Two rules have been considered in the study, i. e. first come first served (FCFS), and shortest processing time (SPT). Average waiting time and productivity were taken into account as performance measures of the system. The result of the study showed that SPT rule gives shorter average waiting time and higher productivity. Based on this result, the SPT rules would be used to control part transporter in order to have a better performance of the FMS.

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