Server Queue Research Articles

Outpatient visits and treatment methods of patients with hand and wrist injuries in Vreden National Medical Research Center of Traumatology and Orthopedics

Background. Number of injuries of the hand and wrist is constantly growing from year to year. Inpatient treatment of these patients increases both time and financial costs for healthcare organizations. Thus, analysing the structure of patients who applied to the emergency department would make it possible to take more objective decisions on the organization of healthcare delivery. The aim — to analyse outpatient visits and treatment methods of patients with hand and wrist injuries who applied to the emergency department of the Vreden National Medical Research Center of Traumatology and Orthopedics. Methods. A sample of 18.848 patients who applied to the emergency department with hand and wrist injury in the period from 2020 to 2023 was drawn in the database of the Medialog medical information system of the Center. Results. The most common types of hand and wrist injuries were: metacarpal and phalangeal fractures, damage to the skin and subcutaneous tissue, damage to the finger flexor tendons and nerves. Of the operations performed, K-wire osteosynthesis and primary suture of the extensor or flexor tendons of the fingers were most often used. Significantly less common were the following operations: primary surgical debridement, suture of nerves and blood vessels, replantation and revascularization. About 20% of patients with hand injuries can receive emergency medical care in emergency rooms of Saint Petersburg, thereby reducing the queue for surgical service in the Center’s emergency department. Conclusion. Treatment of patients with hand and wrist injuries requires comprehensive approach involving doctors of various specialties at each stage of the treatment. Proper organization of such patients’ treatment will significantly improve the quality of medical care and the treatment outcomes.

Limiting distribution for infinite-server batch service queues

Nakamura and Phung-Duc (2023) conjectured that, for an infinite-server batch service queue with Poisson arrivals, the central limit theorem for the number of busy servers, conditioned on the number of waiting customers and the size of the batch to be served, holds as the arrival rate goes to infinity. In this paper, we resolve this conjecture using the theory of Markov regenerative processes and further extend the result to renewal arrival models.

Comprehensive tuning guide: IBM MDM, PME algorithm, services, and configurations

The research paper provides comprehensive guidance on tuning specifics to maximize the efficiency of IBM MDM, particularly in high-performance environments. It addresses several advanced topics and tuning guidelines, focusing on the architectural framework and the details required for sustained performance. Including the recommendations to Handle Long-Chained Duplicates in Suspect Duplicate Processing (SDP), Minimize Deadlocks During Duplicate Processing, and Advanced Database Configurations for High-Performance WebSphere Application Server (WAS) Java Virtual Machine (JVM) and Cache Optimization, and Thread and session management, upgrading the Java version to hava8, Garbage Collection (GC) and Heap Memory Settings, servlet caching, and reduced application logging, MDM Workbench recommendations, Services tuning, and Batch processor tuning. IBM Messaging Queue’s Max server connections and Queue Connection Factory Settings.

Management of the Portfolio of Works For A Public Hospital Complex

Objectives: The main objective of this research is to develop a decision-making support model for prioritizing works projects in a public hospital complex, establishing criteria for characterizing and evaluating these projects. Theoretical reference: Strategic management; management control; project portfolio management; multi-criteria analysis; hospital works projects. Method: This is a quantitative exploratory research based on the Multi-Criterion Decision Support Methodology (MCDA), whose primary data are derived from semi-structured questionnaires. This methodology makes it possible to carry out a multi-criterion analysis of a large quantity of information, involving conflicting interests amongst themselves in decision-making contexts of high uncertainty and high complexity. Results and Discussion: A model for evaluating demands was developed, consisting of 16 criteria for analysis (descriptors), grouped into four thematic groups, whose measurement scales, once transformed into cardinal quantities, present the performance of each characteristic under study and make possible the construction of a global model for evaluating demands. These criteria are based on the decision-makers' perceptions of the institutional needs of works projects, revealing their concerns about the infrastructure problems in the body's buildings. Implications of Research: The implementation of this model leads to the creation of a service queue for the demands of works projects that materializes the priority actions in the area of infrastructure from the objectives, expectations and preferences of the decision makers. In the end, the model developed makes it possible, starting from the attribution and weighting of values, to define institutional priorities. Originality/Value: The research points to a path for overcoming major challenges in the decision-making on the prioritization of works projects in a public hospital, highlighting the high volume of demands, conflicts of interest, resource constraint and obsolescence of buildings and equipment.

Analysis of a Markovian Queue of Single Server Performing in MultiPhase Subject to Disaster, Recovery and Repair

In this paper, we can study about Markovian single-server queue with servers in distinct phases of disaster and repair. The server can stay in full-active Phase or passive Phase randomly and alternately. The server is set to serve in two Phases, such as the full active Phase and passive Phase. When the server operates in full active Phase, the customers arrive and served in First Come: First Serve (FCFS) queue discipline. However, when the server switches from full active to passive Phase, it can only offer to provide service at a rate lower than that of the server in full active Phase. During passive Phase, customers are not allowed to join the system. The server moves to repair Phase immediately after the last customer is served, irrespective of the Phase. The customers will be restricted from joining the queue in repair Phase. After the repair Phase, the server will enter the full active Phase. The server remains in the system for a random period of time. In the event of a disaster, in full active and passive Phases, all customers in system aredropped out, and system moves to repair Phase. The expressions for the steady state probabilities and some key performance metrics are obtained. A numerical illustration is made to study the effects of server shifting from full active phase to passive phase that affects the customers in the system and the occurrence of disaster which has an adverse effect on the customers in that phase.

Cost Optimization in Sintering Process on the Basis of Bulk Queueing System with Diverse Services Modes and Vacation

This research investigated a single bulk server queuing model where service modes and server vacations are dependent on the number of clients. The server operates in three different service modes: single service, fixed batch service, and variable batch service. Modes will be determined by queue length. The service starts only when the minimum number of customers, say ‘a’, has accumulated in the queue. At this point, the server selects one of three service modes. Transitions between duty modes are permitted only at the beginning of a duty period. At the end of the service, the server can go on vacation if the queue length drops below ‘a’. When returning from vacation, if threshold ‘a’ is not reached, the server will remain inactive until it is reached. A special technique called the Supplementary Variables Technique (SVT) was used to determine the probability-generating function when estimating the queue size at a given time. Appropriate numerical examples exemplify the method developed in the paper. An optimal cost analysis was performed to set the threshold values for different server modes with the intention of minimizing the aggregate average cost.

Research of Options for Constructing Information Management Systems Based on Network Models of Queuing Systems

The use of information management systems (IMSs) for the management of technical facilities is currently one of the directions for further improvement and increase in the effectiveness of the use of technical facilities in solving their target tasks. The existing modern IMSs are a set of hardware and software tools designed for collecting, processing and storing information and management. In the presence of a large amount of information and contradictory factors affecting the quality of management, making informed and timely decisions in the management process is impossible without the use of IMSs. The IMSs currently being developed are, for the most part, specialized systems and are designed to solve specific tasks. In this regard, the development and design of IMSs should be carried out taking into account the relationship with the target indicators and features of the management facilities, the results of a comprehensive analysis of information about the IMS elements in the process of functioning, and structural and algorithmic parameters that affect performance indicators. The use of mathematical models for the study of options for the construction of an IMS is the basis for the design and development of devices and subsystems of an IMS. The IMS models currently being developed make it possible to conduct research for single-stage management processes with the presence of similar service facilities in the system. At the same time, modern technical facilities and control systems are complex complexes with cyclically repeating control processes of various types of means. As a rule, such complexes have a set of parallel operating devices (control channels) that provide control of different types of objects at various stages of information processing. In this case, the structure of the IMS must be represented as a multiphase multichannel technical system in which the process of simultaneous management of several objects of various types takes place. In this regard, the purpose of the article is to develop a mathematical model of an IMS with two phases of management and the presence of an arbitrary number of serviced different types of management facilities. The basis of the model is a multiphase CFR network model with a limited waiting time for an application in the service queue. The study on the model allows choosing an option for building an IMS, in particular, choosing the optimal number of control channels for various types of objects according to the criterion of optimality and restrictions on the cost and time of management. An algorithm for selecting an option for building an IMS has been developed, and an example of calculating the number of control channels for managing three types of objects is given.

SPSC: Stream Processing Framework Atop Serverless Computing for Industrial Big Data.

With the advance of smart manufacturing and information technologies, the volume of data to process is increasing accordingly. Current solutions for big data processing resort to distributed stream processing systems, such as Apache Flink and Spark. However, such frameworks face challenges of resource underutilization and high latency in big data application scenarios. In this article, we propose SPSC, a serverless-based stream computing framework where events are discretized into the atomic stream and stateless Lambda functions are taken as context-irrelevant operators, achieving task parallelism and inherent data parallelism in processing. Also, we implement a prototype of the framework on Amazon Web service (AWS) using AWS Lambda, AWS simple queue service, and AWS DynamoDB. The evaluation shows that compared with Alibaba's real-time computing Flink version, SPSC outperforms by 10.12% when the overhead is close.

Pendampingan Penyampaian SPT Tahunan PPh Melalui Program Relawan Pajak Di Kantor Pelayanan Pajak Pratama Pondok Aren

Formal tax compliance through the submission of Annual Income Tax Returns needs to be improved to support the achievement of tax revenue targets. Even though the government provides a convenient way of reporting annual income tax returns using e-filling, many taxpayers still do not report tax returns due to a lack of understanding of how to utilize this tool. The Tax Volunteer Program, which is a collaboration between DJP and universities, is a solution to assist taxpayers in reporting tax returns. The community service team's mentoring process was carried out at KPP Pratama Pondok Aren using e-filling. As a result, many taxpayers have obtained Electronic Proof of Receipt as proof that formal obligations have been fulfilled while reducing service queues at KPP Pratama Pondok Aren as the end of the Annual Income Tax Return reporting period approaches.

Analytic computation for stationary distributions of D-BMAP/D -MSP(a,b)/1 queueing system

ABSTRACT This paper analyses single server correlated batch arrival and correlated batch service queue with innumerable waiting space in discrete-time. The arrival and service processes are governed by discrete batch Markovian arrival process and discrete Markovian service process with general bulk service rule, respectively. Observing two consecutive random epochs, we construct general structure transition probability matrix and it is then reblocked to the desired M/G/1 structure. The UL-type RG-factorization approach combined with spectral expansion method is adopted to unravel the queue length distribution at random epoch. The relationships are undertaken to obtain the queue length distributions at pre-arrival, outside observer's, intermediate and post-departure epochs. Our most challenging effort is to derive the probability mass functions of waiting time and service batch size for arbitrary customer in an arriving batch. We address the warehouse management process for finished products from dealer to retailer as a potential practical use of our batch queue with correlation in both arrival and service, and provide the effect of our queueing behaviour in this application based on our analytical and computational investigation. Based on the implementation of parametrized numeric experiments with numerous categories, we impart our computational results to validate the analytical findings reported in this investigation.

Methodical approach to determining the main parameters of the evacuation system for the wounded with the use of different types of transport

The timeframe for evacuating the wounded is a critical factor that largely determines the fate of a wounded soldier. Even at the initial stage of the war waged by the russian federation against Ukraine, there were almost no frontline ambulances, and there was a critical shortage of ambulances. At present, despite significant efforts to provide the Armed Forces of Ukraine with weapons and military equipment, as well as material and technical means, including medical equipment and property, in particular through international technical assistance, the problem of the lack of the required number of specialised medical evacuation vehicles has not been fully resolved. From this point of view, the issue of correct formulation of requirements for the rational composition and specially equipped various types of vehicles (including sanitary transporters, ambulances), including general use, the system of evacuation of the wounded, and determining the possibility of its further improvement through the methodological apparatus is relevant. The purpose of the article is to present a methodological approach to determining the main parameters of the system of evacuation of the wounded of an operational group of troops with the involvement of various types of transport. The formation of a model of the casualty evacuation system as a mass service network (MSN) will minimise the time spent waiting for medical care by wounded personnel, determine the rational composition of forces and means of the tactical casualty evacuation system. To model the system and processes of evacuation of the wounded from the battlefield during hostilities, including their transportation to medical facilities located in the depths of the third logistics zone, the mathematical apparatus of the theory of mass service was used. In particular, we are talking about the devices of queuing systems (QS) and MSN. The existing system of military evacuation of the wounded and sick is a four-tier system in which all wounded with moderate and severe severity are evacuated. Based on this, the system of evacuation of the wounded can be represented as an MSN, which has a number of features. First of all, this MSN is an open queuing network (OQN), i.e. the flow of requests to enter the network is unlimited, homogeneous and comes from an external independent source. As a result of the calculations, data were obtained on the values of network parameters (average number of applications in queues – 119.47 applications/hour, average number of applications in the network – 158.53 applications/hour, average waiting time for applications in queues for service – 11.95 hours, average time of application stay in the network – 15.85 hours) and the parameters of each QS operating in the MSN – transmission coefficient, incoming flow intensity, load factor, average number of busy channels, average number of applications per QS, average queue length, average waiting time for an application in the service queue, average time for an application to stay in the QS. Analysing the calculated data, from the point of view of creating a rational OQN, the casualty evacuation system achieves maximum efficiency when its productivity in processing the incoming flow of requests is maximised, and the minimum values of such parameters as the number of requests for service in the queue and the number of service channels operating in the network are minimal.

Simulation of Service Queue for Dental Doctor Patients at Kindergarten Hospital. IV 01.07.02 Binjai Using the Exponential Method

One of the systems that can be simulated is a queue. The queuing system consists of a collection of customer servers, a queue that regulates service to customers. The utilization of queuing simulations is to optimize services by designing service resources so that services can be effective and efficient. In the queuing system there are several problems that often occur, for example queuing queues, the number of queues will cause problems such as bored customers, and discomfort will make customers dissatisfied with the service. The Application of the Exponensial Method in the Dentist Patient Service Queuing System There are 28 general populations in this study, namely all consumers at the Kesrem Binjai Hospital, while the target population is the population that is actually used as a data source for patients who queue at the Kesrem Binjai Hospital to get the best service. is the target population in this study.

Information Freshness in Service Queues With Strategic Customers

We examine a scenario in which a service provider updates its queue length information to customers at a specific frequency. Customers decide whether to join the queue based on the most recent update. Our objective is to determine the optimal updating frequency that benefits both the service provider and customers. Using a two-dimensional continuous-time Markov process, we model the actual and announced queue length processes. By proving the identical distributions of these two processes under a Poisson updating scheme, we derive closed-form solutions for customers’ utility functions. Our findings demonstrate that customers adopt a generalized mixed-threshold strategy at equilibrium, and their certainty about whether to join the queue or balk does not always increase with fresher information. Furthermore, we reveal that due to customers’ different sensitivities to information freshness, system performance metrics such as throughput and total customer utility exhibit non-monotonic behavior in response to the updating frequency. Consequently, providing fresher information does not necessarily lead to improved system performance. To address this, we propose algorithms to determine the optimal updating frequency for each system performance metric and identify the conditions under which different updating frequencies are optimal. We demonstrate that any positive updating frequency can achieve customer utility no worse than the no-information system. Additionally, in systems with high customer arrival rates, updating with a positive updating frequency can improve throughput. Furthermore, we prove conditions under which a positive and finite updating frequency can yield higher throughput and total customer utility compared to real-time information systems.

Enhancing queuing theory realism: analysis of reneging behavior impact on M/M/1 drive-thru service system

Individuals seeking services through drive-thru queuing and waiting, anticipate speedy service. However, long queues often prompt customers' impatience, leading to reneging and the early departure from a queue due to perceived excessive waiting. Reneging behavior is often disregarded in queuing analysis, undermining the accuracy and management of queues, resulting in a misrepresentation of real-world scenarios. This study delves into an extensive analysis of a 123-h M/M/1 drive-thru service queue, examining reneging probability and its correlation with customers’ sensitivity to arrival times. Findings reveal that the time between reneging events follows an Exponential distribution, challenging the assumption of a Poisson distribution for reneging rates. The traditional calculation of queue intensity neglects reneging and service abandonment, necessitating modifications to core queuing theory equations for practicality. Integrating reneging behavior enhances the theory’s applicability to real-life queuing dilemmas, improving accuracy and interpretability for effective queue management analysis and strategies, thus directly benefiting business management of queuing systems.

A Bayesian approach to determine sample size in Erlang single server queues

An essential aspect of the practical application of Erlang single-server queues is the statistical inference of their parameters, notably traffic intensity. This metric is crucial as it serves as a fundamental performance indicator, allowing the derivation of other significant measures, including the mean queue size and the expected number of customers in the system. Additionally, it provides the proportion of time the queue system is occupied. This article explores algorithms for calculating sample sizes for these estimations, based on the number of customers who arrived during service periods, a highly intuitive approach, allowing data collection without concerns about correlations among data points. For this purpose, we have considered two forms of informative priors: Gauss hypergeometric and beta priors. Additionally, a non conjugate and objective prior, known as Jeffreys prior, has been taken into account. We present tables with sample sizes for specific configurations and abacuses for more general configurations obtainable through approximate interpolations.

Stability of a Queue Fed by Scheduled Traffic at Critical Loading

Performance of a queueing system with scheduled arrivals A scheduled arrival sequence is one in which customers are scheduled to arrive at constant interarrival times, but each customer’s actual arrival time is perturbed from her scheduled arrival time by a random perturbation. In “Stability of a Queue Fed by Scheduled Traffic at Critical Loading”, V.F. Araman and P.W. Glynn consider a single server queue with deterministic service times in which customers arrive following a scheduled arrival process. Unlike a queue fed by renewal traffic, this queue is shown to be stable even when the utilization is equal to one. It is also shown that for finite mean perturbations, a necessary and sufficient condition for stability is when the positive part of the perturbation has bounded support, with no requirement on the negative part of the perturbation. Perhaps surprisingly, this criterion is not reversible, in the sense that such a queue can be stable for a scheduled traffic process in forward time, but unstable for the time-reversal of the same traffic process.

Time-dependent behaviour of an M/M/3 heterogeneous server queueing system with multiple vacations subject to system disaster

This research paper investigates the dynamic behaviour of a heterogeneous three-server queuing model with multiple vacation. The model also accounts for the possibility that a disaster could occur during busy periods or on vacation, in which case the restoration process would begin immediately. The time-dependent probabilities of system size are presented in the work with explicit equations computed in terms of modified Bessel functions, employing generating functions. To support the theoretical conclusions, numerical examples are given.

Penerapan Model Multi Channel Single Phase dalam Optimisasi Layanan Restoran Cepat Saji

A queue is a waiting line from a service facility. Long queues are caused by the number of consumers who come more than the number of service facilities, it is necessary to apply a queuing model to overcome long queues. This research was conducted at Mc Donald's Jimbaran fast food restaurant because the fast food restaurant is located in a tourist and lecture area, causing queues. The current condition at Mcdonald’s Jimbaran there are more than one service facility, the discipline of the first come first service (FCFS) queue is in accordance with the single-phase multi-channel. After analyzed with data from 31 May 2022 to 06 June 2022 for 7 days. Based on the results of the analysis obtained, it can be concluded that at lunch time requires 4 services while at dinner time only requires 2 service.

Performance evaluation of an appointment-based medical service system with no-shows and emergency arrivals

In an appointment-based service system, patients usually experience two types of delays: appointment delay (virtual wait) and service delay (physical wait). Managers want to give patients more opportunities to make appointments and also want to increase the number of patients served. For this purpose, schedulers allow as many patients as possible to make appointments to wait virtually. Meanwhile, more patients are permitted to wait physically in the waiting room. Do these methods work? We define a discrete time tandem queueing system to analyse the performance measures (patients’ opportunities to make appointments, number of patients served, two waiting times, and utilization of the medical resources) in such a system. These performance measures are obtained by combining an absorbing Markov Chain and two embedded Markov Chains. The parameter sensitivity analysis suggests that increasing the number of patients waiting in the appointment queue and service queue cannot increase their opportunities to make appointments and to be served. Increasing the number of patients is detrimental to the service system. The comparative analysis is carried out to determine the proper model parameters for different management targets. A proper time between consecutive appointments can improve the utilization of medical resources, control patient flow, and increase patients’ access to services.

Analisis Sistem Antrean untuk Mengoptimalkan Pelayanan pada Coffeeshop Teman Sejalan .Co di Karanganyar

Teman Sejalan.co is a Coffeeshop located in Karanganyar and was established in December 2022. Operations in the Teman Sejalan.co Coffeeshop business certainly include from the initial order to pickup. This is related to the queuing system which must improve its service so that customers do not leave if there is a queue. This research uses the Single Channel Multiphase method which is in accordance with the current conditions of Teman Sejalan.co's servers and services. This data was obtained by going directly to the research object during the "Makgedebrews" event by calculating the customer queue time with the number of customers at that time being 103 customers. The results of the research regarding the server line service queue system with H1 and H2 were not proven to be true because the number of customers who were enthusiastic about the event held by Teman Sejalan.co. The use of 1 server lane is not optimal at events that are quite popular with customers which causes queues to pile up, so it is better to use 2 lanes at future events so that it is effective when it is busy.