scholarly journals Path Optimization in 3D Concrete Printing to Minimize Weak Bonds Formation

2019 ◽  
Vol 50 (2) ◽  
pp. 163-168
Author(s):  
Fatima AlSakka ◽  
Mohammad Hasan Senan ◽  
Abdallah Abou Yassin ◽  
Farook Hamzeh
Keyword(s):  
Energy Use ◽  
Structural Integrity ◽  
Rupture Strength ◽  
Discrete Event ◽  
Cost Optimization ◽  
Printing Process ◽  
Event Simulation ◽  
3D Printed ◽  
Adhesion Level

3D concrete printing has proven to be a highly favorable construction method in terms of time reduction, cost optimization, architectural flexibility, sustainability, energy use, and others. However, the quality of the final product certainly has a priority over all of these attractive features of the technology. Yet research has given little consideration to investigating the structural integrity of 3D printed concrete structures. Research states that printed structures exhibit sufficient strength as compared to traditionally built structures. Nevertheless, the fact that this strength is sensitive to numerous factors including the machine setup, the printing process, existing conditions (e. g. temperature) and others, should be studied. A major determinant of the reliability and quality of printed structures is the adhesion level between subsequent layers. Poorly adhered concrete surfaces result in weak bonds that in turn reduce rupture strength. The time elapsed between printing successive concrete layers should be bounded to ensure that concrete is flowable enough to adhere to previous layers. For a given concrete mixture design, this time is a function of travel distance and speed. Thus, this research aims at finding the optimum printing path that minimizes the formation of weak bonds without compromising buildability for a given structure and a defined speed. The research employs Discrete Event Simulation to model the printing process for numerous possible travel paths and assess their adequacy by comparing travel time to allowable time limits.

scholarly journals Discrete event simulation for problem solving in the context of an emergency department

2020 ◽  
Vol 11 (5) ◽  
pp. 1515
Author(s):  
Letícia Ali Figueiredo Ferreira ◽  
Igor Leão dos Santos ◽  
Ana Carla De Souza Gomes dos Santos ◽  
Augusto Da Cunha Reis
Keyword(s):  
Length Of Stay ◽  
Discrete Event Simulation ◽  
Waiting Times ◽  
Discrete Event ◽  
Saturation Point ◽  
Event Simulation ◽  
Emergency Care System ◽  
Patient Arrival ◽  
The Subject

Emergency departments (ED) are responsible for the immediate care and stabilization of patients in critical health conditions. Several factors have caused overcrowding in the emergency care system, but the variability of patient arrival and the triage process requires special attention. The criticality of these components and their configuration directly impact the waiting times, length of stay and quality of service, being the subject of several studies. So, this paper aims to understand by means of Discrete Event Simulation how ED works with the variation of patient arrival and how this variation highlights the bottlenecks of the triage process. Varying the patient arriving interval between 0.1 and 7.6 in a 4-hour scenario,  the system saturation point was established in β = 1.1. Besides, with the variation in the number of triages points, a considerable decrease in the total length of stay spent and the waiting times were noticed, mainly when there was two triage points operating simultaneously.

Characterising Enterprise Application Integration Solutions as Discrete-Event Systems

2016 ◽  
pp. 261-288 ◽  
Author(s):  
Sandro Sawicki ◽  
Rafael Z. Frantz ◽  
Vitor Manuel Basto Fernandes ◽  
Fabricia Roos-Frantz ◽  
Iryna Yevseyeva ◽  
...  
Keyword(s):  
Discrete Event ◽  
Enterprise Application Integration ◽  
Application Integration ◽  
Art Integration ◽  
Event Simulation ◽  
Domain Specific ◽  
Enterprise Application ◽  
Software Engineers ◽  
Exchange Data

It is not difficult to find an enterprise which has a software ecosystem composed of applications that were built using different technologies, data models, operating systems, and most often were not designed to exchange data and share functionalities. Enterprise Application Integration provides methodologies and tools to design and implement integration solutions. The state-of-the-art integration technologies provide a domain-specific language that enables the design of conceptual models for integration solutions. The analysis of integration solutions to predict their behaviour and find possible performance bottlenecks is an important activity that contributes to increase the quality of the delivered solutions, however, software engineers follow a costly, risky, and time-consuming approach. Integration solutions shall be understood as a discrete-event system. This chapter introduces a new approach based on simulation to take advantage of well-established techniques and tools for discrete-event simulation, cutting down cost, risk, and time to deliver better integration solutions.

Simulation of home-hospital impacts on crowding – FM implications

Facilities ◽  
2016 ◽  
Vol 34 (13/14) ◽  
pp. 748-765 ◽  
Author(s):  
John Fard ◽  
Kathy O. Roper ◽  
Jeremy Hess
Keyword(s):  
Discrete Event ◽  
Facility Management ◽  
Content Type ◽  
Hospital Capacity ◽  
Event Simulation ◽  
Hospital Facility ◽  
Ed Crowding ◽  
The Impact

Purpose This study aims to evaluate home-hospital implications for facility management (FM) and, in particular, ED crowding. Home-hospital programs, in which select patients receive hospital-level care at home, can extend hospital facility capacity. Emergency department (ED) crowding, a sensitive hospital capacity indicator, is associated with unsafe operations and reduced quality of care. Design/methodology/approach The impact of a home-hospital program on crowding was analyzed with a discrete-event simulation model using one month of historical data from a case hospital. Time ED patients waited for inpatient beds was the primary endpoint. Five scenarios with different levels of patient suitability for home-hospital were each run 30 times. Differences were evaluated using paired t-tests. Findings Implementing home-hospital reduced ED crowding by up to 3 per cent. Additionally, the simulation yielded insights regarding advantages and limitations of various home-hospital arrangements, suggested which hospital types may be the best candidates for home-hospital and highlighted the role of bed-cleaning turnaround times and environmental services staffing schedules in operations. Research limitations/implications This research examined home-hospital and crowding at one hospital. Developing a model that accounts for all hospital types requires significant data and many hospital partnerships but could allow for more informed decisions regarding implementation of such programs. Social implications This research has implications for ensuring access to ED care, an important source of acute care generally and particularly for the underserved. Originality/value This research systematically evaluates home-hospital’s impact on ED crowding. Simulation modeling resulted in analytical results and allowed for evaluation of what-if scenarios providing recommendations for hospital FMs on their role in decreasing ED boarding.

scholarly journals Practical Benefits of Aspect-Oriented Programming Paradigm in Discrete Event Simulation

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Meriem Chibani ◽  
Brahim Belattar ◽  
Abdelhabib Bourouis
Keyword(s):  
Discrete Event Simulation ◽  
Discrete Event ◽  
Separation Of Concerns ◽  
Quality Factors ◽  
Crosscutting Concerns ◽  
Simulation Tools ◽  
Event Simulation ◽  
Aspect Oriented Modeling ◽  
Simulation Systems

Aspect-oriented modeling and simulation is a new approach which uses the separation of concerns principle to enhance the quality of models and simulation tools. It adopts the separation of concerns (SOC) principle. Thus, crosscutting concerns such as processes synchronization, steady state detection, and graphical animation could be separated from simulation functional modules. The capture of crosscutting concerns in a modular way is carried out to cope with complexity and to achieve the required engineering quality factors such as robustness, modularity, adaptability, and reusability. This paper provides a summary of aspect-oriented paradigm with its usage in simulation by illustrating the main crosscutting concerns that may infect simulation systems. A practical example is given with the use of the Japrosim discrete event simulation library.

scholarly journals Optimising Outpatient Pharmacy Staffing to Minimise Patients Queue Time using Discrete Event Simulation

2021 ◽  
Vol 7 (2) ◽  
pp. 102
Author(s):  
Putri Amelia ◽  
Artya Lathifah ◽  
Muhammad Dliya'ul Haq ◽  
Christoph Lorenz Reimann ◽  
Yudi Setiawan
Keyword(s):  
Waiting Time ◽  
Discrete Event ◽  
Outpatient Service ◽  
Simulation Method ◽  
Quality Of Services ◽  
Discrete Simulation ◽  
Event Simulation ◽  
Unit System ◽  
Effectiveness Analysis

Background: To remain relevant in the customer-oriented market, hospitals must pay attention to the quality of services and meet customers' expectations from admission to discharge stage. For an outpatient customer, pharmacy is the last unit visited before discharge. It is likely to influence patient satisfaction and reflect the quality of hospital's service. However, at certain hospitals, the waiting time is long. Resources need to be deployed strategically to reduce queue time. Objective: This research aims to arrange the number of staff (pharmacists and workers) in each station in the pharmacy outpatient service to minimise the queue time.Methods: A discrete simulation method is used to observe the waiting time spent at the pharmacy. The simulation run is valid and effective to test the scenario. Results: It is recommended to add more personnel for the non-compounding medicine and packaging to reduce the waiting time by 22.41%Conclusion: By adding personnel to non-compounding and packaging stations, the system performance could be improved. Cost-effectiveness analysis should be done to corroborate the finding. Keywords: Discrete Event Simulation, Hospital, Outpatient Service, Pharmacy Unit, System AnalysisBackground: To remain relevant in the customer-oriented market, hospitals must pay attention to the quality of services and meet customers' expectations from admission to discharge stage. For an outpatient customer, pharmacy is the last unit visited before discharge. It is likely to influence patient satisfaction and reflect the quality of hospital's service. However, at certain hospitals, the waiting time is long. Resources need to be deployed strategically to reduce queue time. Objective: This research aims to arrange the number of staff (pharmacists and workers) in each station in the pharmacy outpatient service to minimise the queue time.Methods: A discrete simulation method is used to observe the waiting time spent at the pharmacy. The simulation run is valid and effective to test the scenario. Results: It is recommended to add more personnel for the non-compounding medicine and packaging to reduce the waiting time by 22.41%Conclusion: By adding personnel to non-compounding and packaging stations, the system performance could be improved. Cost-effectiveness analysis should be done to corroborate the finding. Keywords:Discrete Event Simulation, Hospital, Outpatient Service, Pharmacy Unit, System Analysis

Design for a Closed-Loop Supply Chain System With Sensor-Embedded Refrigerators

2019 ◽  
pp. 1-24
Author(s):  
Mehmet Talha Dulman ◽  
Surendra M. Gupta
Keyword(s):  
Supply Chain ◽  
Embedded Systems ◽  
Discrete Event Simulation ◽  
Closed Loop ◽  
Discrete Event ◽  
Supply Chain System ◽  
Event Simulation ◽  
Closed Loop Supply Chains

This chapter presents a methodology to evaluate the benefit of using sensors in closed-loop supply chains. Sensors can be embedded into products to collect helpful information during their use and end-of-life (EOL) phases. This information can subsequently be employed to estimate the remaining lives of components and products and to ensure that proper maintenance is provided to avoid premature failures. The information is also useful in determining the quality of the components and products when planning EOL operations such as disassembly, inspection, and remanufacturing. To statistically illustrate these benefits, discrete event simulation is employed to a case study consisting of regular and sensor-embedded refrigerator systems. A design of experiments study is then employed where experiments are run to compare the two systems. The results reveal that the sensor-embedded systems perform much better than the regular systems in terms of disassembly costs, inspection costs, and EOL profits generated by selling the remanufactured products and components.

DIMINISHING CAPACITY REQUIREMENT FOR MOBILITY DATABASE IN WIRELESS ATM

2004 ◽  
Vol 13 (02) ◽  
pp. 271-291
Author(s):  
KUEN-LIANG SUE ◽  
CHI-CHUN LO
Keyword(s):  
Discrete Event ◽  
Wireless Atm ◽  
Event Simulation ◽  
Location Register ◽  
Mobility Database ◽  
Visitor Location Register ◽  
Key Factor ◽  
The Cost ◽  
Second Chance

In wireless ATM, Visitor Location Register (VLR) is the database that supports mobility management. In case the number of roaming users exceeds the VLR supports, the arriving users cannot receive any service. To solve the problem, the Random Replacement (RR) policy randomly selects a victim record in VLR to be replaced with the record of the arriving user. The quality of services for the victim user will certainly drop. Therefore, the proportion of affected users is not allowed to exceed a tolerable threshold. Apparently, VLR size is the key factor of the threshold. The cost for maintaining a VLR increases significantly as its size grows. So, how to utilize the capacity efficiently is an important issue in VLR planning. We propose a Second Chance Replacement (SCR) policy to reduce the requirements for VLR capacity. As compared with the RR policy, the discrete-event simulation results show that the SCR policy can save 2.5% to 28% VLR size under various QoS thresholds.

scholarly journals The Effectiveness of Using Discrete Event Simulation to Optimize the Quality of Service of Outpatient in Iraq: A Case Study

2021 ◽  
Vol 8 (1) ◽  
pp. 40-49
Author(s):  
Maysoon A. Mohammed ◽  
Shaymaa Kadhim Mohsin ◽  
Sarah Jasim Mohammed
Keyword(s):  
Waiting Time ◽  
Discrete Event ◽  
Outpatient Clinics ◽  
Discrete Events ◽  
Event Simulation ◽  
Dental Clinics ◽  
Long Time ◽  
Rich Material

One of the most important healthcare institutions in Iraq is Outpatient clinic that requires a lot of thinking to improve the way to provide services and the nature of care. Outpatient clinics are increasingly keen to meet the needs of care, and this has been recognized as a fundamental issue related to service quality. Therefore, many researchers in various fields have taken this matter as a basis for their research, as it is considered a rich material for research due to the problems these institutions contain. The most important problems faced by outpatient clinics are the waiting time and the insufficient number of clinic staff to perform the various tasks. The aim of this paper is to reduce the waiting time by building a model for the clinic environment, especially dental clinics, and trying to benefit from all the existing medical staff and exploit their experiences. Since the patient spends a long time between registration, returning to the doctor and finally the result or process that the doctor performs, building such a model might help in identifying and improving the problem. The simulation model built in this research for the clinic is based on modelling the discrete events inside the dental clinic using the Arena software. This form is used to assess the quality of services provided by dental outpatient clinics in Iraq.

scholarly journals A simulation based performance evaluation of optical ethernet switch

2020 ◽  
Vol 17 (3) ◽  
pp. 1639
Author(s):  
Dawit Hadush Hailu ◽  
Gebrehiwet Gebrekrstos Lema ◽  
Gebremichael T. Tesfamariam ◽  
Tole Sutikno
Keyword(s):  
Quality Of Service ◽  
Discrete Event ◽  
Access Network ◽  
Packet Delay ◽  
Event Simulation ◽  
Cloud Radio Access Network ◽  
Radio Access ◽  
Simulation Based ◽  
Ethernet Switch

<p class="FigureCaption"><span>With the advent of several new cloud radio access network (C-RAN) technologies, today’s networking environment is dramatically altered and is experiencing a rapid transformation. One of the most important is ethernet based C-RAN, in support of which many products such as optical Ethernet switches have recently appeared on the market. This paper presents the performance analysis of such switches with respect to packet loss ratio (PLR), latency and packet delay variation (PDV). We employed the Simula based on discrete event modelling on Simula (DEMOS), a context class for discrete event simulation to simulate a cut-through optical ethernet switch under two types of traffics: high priority (HP) traffic and low priority (LP) traffic. In this way, the paper evaluates the optical Ethernet switch performance quantitatively. The results obtained from the simulator showed that the high quality of service was reflected on HP traffic and the low quality of service in LP traffic. Hence, HP traffic can be used for transporting radio over ethernet (RoE) traffic while LP traffic can used for transporting time insensitive application. It is also found that HP traffic experiences a PDV equals to the duration of maximum sized LP traffic in Optical Ethernet switch.</span></p>

scholarly journals Developing an Approach to Quantify Nurse Workload and Quality of Care Using Discrete Event Simulation

2021 ◽  
Author(s):  
Sadeem Munawar Qureshi
Keyword(s):  
Quality Of Care ◽  
Discrete Event Simulation ◽  
Discrete Event ◽  
Patient Acuity ◽  
Event Simulation ◽  
Number Of Patients ◽  
Nurse Workload ◽  
Care Demands ◽  
Des Model

Intensive workload for nurses due to high demands directly impacts the quality of care and nurses’ health. To better manage workload, it is necessary to understand the drivers of workload. This multidisciplinary research provides an adaptable nurse-focused approach to discrete event simulation (DES) modelling that can quantify the effects of changing technical design and operational policies in terms of nurse workload and quality of care. In the first phase of this research, a demonstrator model was developed that explored the impact of nurse-patient ratios. As the number of patients per nurse (nurse-patient ratio) increased, nurse workload increased, and the quality of care deteriorated. In the second phase of this research, the DES model tested the interaction of patient acuity and nurse-patient ratios. As the levels of patient acuity and number of patients per nurse increased, nurse workload increased, and quality of care deteriorated – a result that was not surprising but an ability to quantify this proactively, was conceived. In the third phase of this research, the DES model was validated by means of an external field validation study by adapting the model to a real-world unit. The DES model showed excellent consistency between modelling and real-world outcomes (Intraclass iv Correlation Coefficient = 0.85 to 0.99; Spearman Rank-order Correlation Coefficient = 0.78). The fourth phase of this research used the validated simulation model to test the design implication of geographical patient bed assignment. As nurses were assigned to patient beds further away from the center of the unit or spread further apart, nurse workload increased as the nurse had to walk more leading to a deterioration in the quality of care. The DES modelling capability showed that both aspects of assignment were important for patient bed assignment. The fifth phase of this research combined Digital Human Modelling (DHM) and DES to produce a time-trace of biomechanical load and peak biomechanical load (‘activity’) for a full shift of nursing work. As the nurse was assigned to beds further away from the center of the unit, the cumulative biomechanical load decreased as the nurse spent more time walking yielding a reduced biomechanical load in comparison to the task group ‘activity’. As patient acuity is increased, a decrease in L4/L5 moment is observed as the task duration and frequency of most care task increase. Due to increased care demands, nurses must now spend more time delivering care. Since the care demands are much higher than the current capability of nurses, quality of care is deteriorated. As number of patients per nurse, increased a ‘ceiling’ effect on biomechanical load can be observed as nurses do not have the time to attend to this extra demand for care. The use of this adaptable DES modeling approach can assist decision makers by providing quantifiable information on the potential impact of these decisions on nurse workload and quality of care. Thereby, assisting decision makers to create technical design and operational policies for hospital units that do not compromise patient safety and health of nurses. Keywords: Behavioural operations research; Discrete Event Simulation; Nurse Workload; Quality of care; Healthcare Ergonomics; Human Factors Engineering; Nurses; Healthcare policy

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