scholarly journals We Are on the Way: Analysis of On-Demand Ride-Hailing Systems

2020 ◽  
Author(s):  
Guiyun Feng ◽  
Guangwen Kong ◽  
Zizhuo Wang
Keyword(s):  
Waiting Time ◽  
Heuristic Method ◽  
Problem Definition ◽  
Lower Efficiency ◽  
Average Waiting Time ◽  
On Demand ◽  
Trade Offs ◽  
Matching Mechanism ◽  
Service Paradigm ◽  
The Impact

Problem definition: Recently, there has been a rapid rise of on-demand ride-hailing platforms, such as Uber and Didi, which allow passengers with smartphones to submit trip requests and match them to drivers based on their locations and drivers’ availability. This increased demand has raised questions about how such a new matching mechanism will affect the efficiency of the transportation system—in particular, whether it will help reduce passengers’ average waiting time compared with traditional street-hailing systems. Academic/practical relevance: The on-demand ride-hailing problem has gained much academic interest recently. The results we find in the ride-hailing system have a significant deviation from classic queueing theory where en route time does not play a role. Methodology: In this paper, we shed light on this question by building a stylized model of a circular road and comparing the average waiting times of passengers under various matching mechanisms. Results: We discover the inefficiency in the on-demand ride-hailing system when the en route time is long, which may result in nonmonotonicity of passengers’ average waiting time as the passenger arrival rate increases. After identifying key trade-offs between different mechanisms, we find that the on-demand matching mechanism could result in lower efficiency than the traditional street-hailing mechanism when the system utilization level is medium and the road length is long. Managerial implications: To overcome the disadvantage of both systems, we further propose adding response caps to the on-demand ride-hailing mechanism and develop a heuristic method to calculate a near-optimal cap. We also examine the impact of passenger abandonments, idle time strategies of taxis, and traffic congestion on the performance of the ride-hailing systems. The results of this research would be instrumental for understanding the trade-offs of the new service paradigm and thus enable policy makers to make more informed decisions when enacting regulations for this emerging service paradigm.

scholarly journals Exploring the Performance of Different On-Demand Transit Services Provided by a Fleet of Shared Automated Vehicles: An Agent-Based Model

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Senlei Wang ◽  
Goncalo Homem de Almeida Correia ◽  
Hai Xiang Lin
Keyword(s):  
Waiting Time ◽  
System Capacity ◽  
Great Promise ◽  
Agent Based Model ◽  
Automated Vehicles ◽  
Time Service ◽  
Agent Based ◽  
Transit Service ◽  
Average Waiting Time ◽  
On Demand

Automated vehicles used as public transport show a great promise of revolutionizing current transportation systems. Still, there are many questions as to how these systems should be organized and operated in cities to bring the best out of future services. In this study, an agent-based model (ABM) is developed to simulate the on-demand operations of shared automated vehicles (SAVs) in a parallel transit service (PTS) and a tailored time-varying transit service (TVTS). The proposed TVTS system can switch service schemes between a door-to-door service (DDS) and a station-to-station service (SSS) according to what is best for the service providers and the travelers. In addition, the proposed PTS system that allows DDS and SSS to operate simultaneously is simulated. To test the conceptual design of the proposed SAV system, simulation experiments are performed in a hypothetical urban area to show the potential of different SAV schemes. Simulation results suggest that SAV systems together with dynamic ridesharing can significantly reduce average waiting time, the vehicle kilometres travelled and empty SAV trips. Moreover, the proposed optimal vehicle assignment algorithm can significantly reduce the empty vehicle kilometres travelled (VKT) for the pickups for all tested SAV systems up to about 40% and improve the system capacity for transporting the passengers. Comparing the TVTS system, which has inconvenient access in peak hours, with the PTS systems, which always makes available door-to-door transport, we conclude that the latter could achieve a similar system performance as the former in terms of average waiting time, service time and system capacity.

scholarly journals Impact of battery-powered orthopedic drills on the practice of orthopedic surgery in a resource limited country

2018 ◽  
Vol 5 (3) ◽  
pp. 954
Author(s):  
Paa K. Baidoo ◽  
Agbeko Ocloo ◽  
Velarie Ansu ◽  
Joojo N. Baidoo
Keyword(s):  
Operating Room ◽  
Waiting Time ◽  
Post Intervention ◽  
Average Waiting Time ◽  
Resource Limited ◽  
Major Teaching Hospital ◽  
Average Patient ◽  
Major Teaching ◽  
Patient Waiting Time ◽  
The Impact

Background: The study aimed at assessing the impact of the availability of battery-powered drills on the management of orthopedic cases presenting to the orthopedic unit of the department of surgery at a major teaching hospital serving the southern part of Ghana.Methods: This study was a single center retrospective study. Authors examined the total number of cases, average time spent on cases in the operating room, and the average patient waiting time for surgery between January 2012 and December 2014. A paired sample t-test was used to evaluate the effectiveness of the orthopedic drills for the pre-and post-intervention periods.Results: There were statistical significant differences in the total number of cases (p<0.01), the average time spent on cases in the operating room (p<0.01), and the average waiting time for surgery (p<0.05) between January 2012 to June 2013 when manual hand drills were in use and July 2013 to December 2014 when the battery-powered drills were introduced.Conclusions: The introduction of the battery-powered drills led to a significant improvement in the total number of cases done. There was a reduction in time spent per case in the operating room as well as the average waiting time to having surgery. 

Evaluating intensive care unit admission and discharge policies using a discrete event simulation model

SIMULATION ◽  
2020 ◽  
Vol 96 (6) ◽  
pp. 501-518 ◽  
Author(s):  
Imran Hasan ◽  
Esmaeil Bahalkeh ◽  
Yuehwern Yih
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Discrete Event Simulation ◽  
Waiting Time ◽  
Discrete Event ◽  
Wait Time ◽  
Average Waiting Time ◽  
Event Simulation ◽  
The Impact ◽  
Patient Mix

The efficient utilization and management of a scarce resource such as the intensive care unit (ICU) is critical to the smooth functioning of a hospital. This study investigates the impact of a set of operational policies on ICU behavior and performance. Specifically, the implemented policies are (a) wait time thresholds on how long patients can wait for an ICU bed, (b) the time windows during which patient discharges and transfers take place, and (c) different patient mix combinations. The average waiting time of patients for ICU beds and the admission ratio, the ratio of admitted patients to total ICU bed requests, are the performance measures under consideration. Using discrete event simulation, followed by analysis of variance and post hoc tests (Tukey multiple comparison), it is shown that increasing discharge windows has a statistically significant impact on the total number of admissions and average patient wait times. Moreover, average waiting time increased when wait time thresholds increased, especially when the number of emergency surgeries in the mix increased. In addition, larger proportions of elective surgery patients in the patient mix population can lead to significantly reduced ICU performance.

scholarly journals EP.WE.338Ambulatory Ultrasound Scans Reduce Inpatient Admissions During COVID-19: A Need for the Expansion of Ambulatory Services

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
L Cornett ◽  
S Davidson ◽  
K McElvanna
Keyword(s):  
Emergency Department ◽  
Waiting Time ◽  
Retrospective Review ◽  
First Line ◽  
Average Waiting Time ◽  
Number Of Patients ◽  
Line Imaging ◽  
Ambulatory Services ◽  
The Impact

Abstract Aim With the increased need to manage patients out of hospital during COVID-19, it was anticipated that need for ambulatory imaging would increase. This study aimed to assess the demand for ambulatory ultrasounds (US) during the COVID-19 pandemic and the impact on inpatient admissions. Methods A retrospective review of patients presenting to the Emergency Department (ED) between 12th July – 23rd August 2020 who required an US as first line imaging. Electronic Care Records were used to collect data regarding type of US i.e., inpatient, or ambulatory, time taken for ambulatory US and outcome after imaging. The same period in 2019 was assessed for comparison. Results In 2020, 100 patients required an US compared to 88 in 2019. 37% (37/100) of which were discharged for an ambulatory US, compared to 14.8% (13/88) in 2019 (p = 0.006). The average waiting time for an ambulatory US in 2019 was 2 days, this increased to 7 days in 2020. Following ambulatory US in 2020 43.2% (16/37) required further outpatient imaging or assessment; similar outcomes were seen in 2019 with 46.2% (6/13). Overall, there was a 150% increase in the use of ambulatory US, with a 26% decrease in admissions in 2020 vs. 2019. Conclusions There was a significant increase in the number of patients discharged from ED to undergo an ambulatory US resulting in reduced inpatient admissions. This increase in demand is reflected by the prolonged waiting time highlighting the requirement for expansion of ambulatory services to meet this clinical need.

scholarly journals The impact of differing frames on early stages of intersectoral collaboration: the case of the First 1000 Days Initiative in the Western Cape Province

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Ida Okeyo ◽  
Uta Lehmann ◽  
Helen Schneider
Keyword(s):  
Problem Definition ◽  
Intersectoral Collaboration ◽  
Western Cape ◽  
Western Cape Province ◽  
Policy Problem ◽  
Documentary Analysis ◽  
Trade Offs ◽  
Problems And Solutions ◽  
Disciplinary Background ◽  
The Impact

Abstract Background While intersectoral collaboration is considered valuable and important for achieving health outcomes, there are few examples of successes. The literature on intersectoral collaboration suggests that success relies on a shared understanding of what can be achieved collectively and whether stakeholders can agree on mutual goals or acceptable trade-offs. When health systems are faced with negotiating intersectoral responses to complex issues, achieving consensus across sectors can be a challenging and uncertain process. Stakeholders may present divergent framings of the problem based on their disciplinary background, interests and institutional mandates. This raises an important question about how different frames of problems and solutions affect the potential to work across sectors during the initiating phases of the policy process. Methods In this paper, this question was addressed through an analysis of the case of the First 1000 Days (FTD) Initiative, an intersectoral approach targeting early childhood in the Western Cape Province of South Africa. We conducted a documentary analysis of 34 policy and other documents on FTD (spanning global, national and subnational spheres) using Schmidt’s conceptualisation of policy ideas in order to elicit framings of the policy problem and solutions. Results We identified three main frames, associated with different sectoral positionings — a biomedical frame, a nurturing care frame and a socioeconomic frame. Anchored in these different frames, ideas of the problem (definition) and appropriate policy solutions engaged with FTD and the task of intersectoral collaboration at different levels, with a variety of (sometimes cross) purposes. Conclusions The paper concludes on the importance of principled engagement processes at the beginning of collaborative processes to ensure that different framings are revealed, reflected upon and negotiated in order to arrive at a joint determination of common goals.

scholarly journals 805 A Dangerous Wait: The Impact of Prolonged Waiting Times in Endocrine Surgery

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
R Shuttleworth ◽  
F Eatock
Keyword(s):  
Patient Safety ◽  
Northern Ireland ◽  
Waiting Time ◽  
Safety Concern ◽  
Waiting Times ◽  
Waiting List ◽  
Endocrine Surgery ◽  
Day Case ◽  
Average Waiting Time ◽  
The Impact

Abstract Aim In Northern Ireland on 31/12/19 90,514 patients were awaiting admission/day case procedure. The 2019/2020 Ministerial waiting time target states that by March 2020, 55% of patients should not wait longer than 13 weeks for inpatient/day case treatment, and no patient should wait longer than 52 weeks. This audit investigates the impact of long waiting times in endocrine surgery and how they impact patient safety. Method Data was collected from the endocrine surgery waiting list in the Royal Victoria Hospital, Belfast, up to 6/2/20. Number of days spent on the waiting list, disease complications and the number of days before they occurred were collated. Results 118 patients were awaiting endocrine surgery. The average waiting time was 533 days. 21 patients experience 27 complications related to their endocrine disease whilst waiting for surgery. The average duration before complications was 490 days; 4 required admission, 11 required medical intervention and 3 required a surgical intervention. Conclusions The average waiting time for endocrine surgery is greater than 52 weeks. In Northern Ireland no one should be waiting more than 52 weeks. The length of the waiting list has resulted in 1 in 5 experiencing complications and prolonged suffering from under-treated disease. This is a significant patient safety concern. Urgent action to address waiting lists is required and the disruption caused by COVID-19 should be used as a catalyst for reform.

Reading Between the Stars: Understanding the Effects of Online Customer Reviews on Product Demand

2021 ◽  
Author(s):  
Hallie S. Cho ◽  
Manuel E. Sosa ◽  
Sameer Hasija
Keyword(s):  
Choice Model ◽  
Online Reviews ◽  
Causal Link ◽  
Problem Definition ◽  
Exogenous Shock ◽  
Customer Reviews ◽  
Product Demand ◽  
On Demand ◽  
The Impact ◽  
Positive Effect

Problem definition: Many studies have examined quantitative customer reviews (i.e., star ratings) and found them to be a reliable source of information that has a positive effect on product demand. Yet the effect of qualitative customer reviews (i.e., text reviews) on demand has been less thoroughly studied, and it is not known whether (or how) the sentiment expressed in text reviews moderates the influence of star ratings on product demand. We are therefore led to examine how the interplay between review sentiment and star ratings affects product demand. Academic/practical relevance: Consumer perceptions of product quality and how they are shared via customer reviews are of extreme relevance to the firm, but we still do not understand how product demand is affected by the quantitative and qualitative aspects of customer reviews. Our paper seeks to fill this critical gap in the literature by analyzing star ratings, the sentiment of customer reviews, and their interaction. Methodology: Using 2002–2013 data for the U.S. automobile market, we investigate empirically the impact of star ratings and review sentiment on product demand. Thus, we estimate an aggregated multinomial choice model after performing a machine learning–based sentiment analysis on the entire corpus of customer reviews included in our sample. We take advantage of a quasi-exogenous shock to establish a causal link between online reviews and product demand. Results: We find robust empirical evidence that (i) review sentiment and star ratings both have a decreasingly positive effect on product demand and (ii) the effect (on demand) of their interaction suggests that the two components of reviews are complements. Positive sentiments in text reviews increase the positive effect of ratings when the effect of ratings is decidedly positive while they also compensate for the tendency of consumers to discount extremely high star ratings. Managerial implications: The firm should pay greater attention to quantitative and qualitative customer reviews to better understand how consumers perceive the quality of its offerings.

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