scholarly journals Modeling the Impact of School-Based Universal Depression Screening on Additional Service Capacity Needs: A System Dynamics Approach

Author(s):  
Aaron R. Lyon ◽  
Melissa A. Maras ◽  
Christina M. Pate ◽  
Takeru Igusa ◽  
Ann Vander Stoep
2020 ◽  
Vol 68 (6) ◽  
pp. 1648-1667
Author(s):  
Jinting Wang ◽  
Zhongbin Wang ◽  
Yunan Liu

Customer retrials commonly occur in many service systems, such as healthcare, call centers, mobile networks, computer systems, and inventory systems. However, because of their complex nature, retrial queues are often more difficult to analyze than queues without retrials. In “Reducing Delay in Retrial Queues by Simultaneously Differentiating Service and Retrial Rates”, J. Wang, Z. Wang, and Y. Liu develop a service grade differentiation policy for queueing models with customer retrials. They show that the average waiting time can be reduced through strategically allocating the rates of service and retrial times without needing additional service capacity. Counter to the intuition that higher service variability usually yields a larger delay, the authors show that the benefits of this simultaneous service-and-retrial differentiation (SSRD) policy outweigh the impact of the increased service variability. To validate the effectiveness of the new SSRD policy, the authors provide (i) conditions under which SSRD is more beneficial, (ii) closed-form expressions of the optimal policy, (iii) asymptotic reduction of customer delays when the system is in heavy traffic, and (iv) insightful observations/discussions and numerical results.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ganna Rozhnova ◽  
Christiaan H. van Dorp ◽  
Patricia Bruijning-Verhagen ◽  
Martin C. J. Bootsma ◽  
Janneke H. H. M. van de Wijgert ◽  
...  

AbstractThe role of school-based contacts in the epidemiology of SARS-CoV-2 is incompletely understood. We use an age-structured transmission model fitted to age-specific seroprevalence and hospital admission data to assess the effects of school-based measures at different time points during the COVID-19 pandemic in the Netherlands. Our analyses suggest that the impact of measures reducing school-based contacts depends on the remaining opportunities to reduce non-school-based contacts. If opportunities to reduce the effective reproduction number (Re) with non-school-based measures are exhausted or undesired and Re is still close to 1, the additional benefit of school-based measures may be considerable, particularly among older school children. As two examples, we demonstrate that keeping schools closed after the summer holidays in 2020, in the absence of other measures, would not have prevented the second pandemic wave in autumn 2020 but closing schools in November 2020 could have reduced Re below 1, with unchanged non-school-based contacts.


2006 ◽  
Vol 25 (1) ◽  
pp. 13-29
Author(s):  
Nikitas A. Assimakopoulos ◽  
Anastasios N. Riggas

The starting point for establishing a Virtual Enterprise is a set of existing enterprises which might contribute with some of their functionalities (core competencies) to the formation of the virtual entity. The most important issue, in this formation, is the rapid integration of the business processes of the participating companies. The architecture of the VE must assist companies desiring to enter into a virtual relationship by defining the functions and interfaces of critical business processes, thus allowing for a more rapid and efficient integration of the expertise which will be contributed by each partner in the virtual enterprise. While the integration of computer and communication technologies are no doubt critical issues, the successful attainment of the business goals of the virtual enterprise often depends on its ability to align the business processes and practices of partner enterprises. Focus of this paper, is the presentation of Structured System Dynamics (SSPS) multi-methodology for the design and the evaluation of a Virtual Enterprise Architecture. SSPS uses Systems Thinking and System Dynamics principles as launch pad for its approach. The Systemic Methodologies of Problem Structuring Methodology (PSM) and SAST are also integrated in this new Multi-Methodology. SSPS is a new practical and scientific tool in designing and evaluating a VE architecture providing the ability to determine the impact, reliability, success of the Architectures' models created, refine them and identify potential process improvements. A framework for the rapid and efficient integration of the business processes of the participating companies in the virtual enterprise is provided. For this multi-methodology, a real-life application is also presented for a Virtual Enterprise that constructs Wireless Payment Mechanisms.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ka Chun Chong ◽  
Hong Fung ◽  
Carrie Ho Kwan Yam ◽  
Patsy Yuen Kwan Chau ◽  
Tsz Yu Chow ◽  
...  

Abstract Background The elderly healthcare voucher (EHCV) scheme is expected to lead to an increase in the number of elderly people selecting private primary healthcare services and reduce reliance on the public sector in Hong Kong. However, studies thus far have reported that this scheme has not received satisfactory responses. In this study, we examined changes in the ratio of visits between public and private doctors in primary care (to measure reliance on the public sector) for different strategic scenarios in the EHCV scheme. Methods Based on comments from an expert panel, a system dynamics model was formulated to simulate the impact of various enhanced strategies in the scheme: increasing voucher amounts, lowering the age eligibility, and designating vouchers for chronic conditions follow-up. Data and statistics for the model calibration were collected from various sources. Results The simulation results show that the current EHCV scheme is unable to reduce the utilization of public healthcare services, as well as the ratio of visits between public and private primary care among the local aging population. When comparing three different tested scenarios, even if the increase in the annual voucher amount could be maintained at the current pace or the age eligibility can be lowered to include those aged 60 years, the impact on shifts from public-to-private utilization were insignificant. The public-to-private ratio could only be marginally reduced from 0.74 to 0.64 in the first several years. Nevertheless, introducing a chronic disease-oriented voucher could result in a significant drop of 0.50 in the public-to-private ratio during the early implementation phase. However, the effect could not be maintained for an extended period. Conclusions Our findings will assist officials in improving the design of the EHCV scheme, within the wider context of promoting primary care among the elderly. We suggest that an additional chronic disease-oriented voucher can serve as an alternative strategy. The scheme must be redesigned to address more specific objectives or provide a separate voucher that promotes under-utilized healthcare services (e.g., preventive care), instead of services designed for unspecified reasons, which may lead to concerns regarding exploitation.


Author(s):  
Taulant Kerci ◽  
Mohammed Ahsan Adib Murad ◽  
Ioannis Dassios ◽  
Federico Milano

2020 ◽  
Vol 12 (4) ◽  
pp. 1578 ◽  
Author(s):  
Hongxia Sun ◽  
Yao Wan ◽  
Huirong Lv

Exhaust pollution and energy crises are worsening worldwide. China has become the largest motor vehicle producer; thus, promoting the use of new energy vehicles (NEVs) in China has important practical significance. In this paper, considering the limited rationality of governments, NEV enterprises and consumers, we study the subsidy policy of the China NEV market using the evolutionary game and system dynamics (SD) methods. First, a tripartite evolutionary game model is developed and the replicator dynamics equations and Jacobian matrix are obtained. A SD simulation of the model was conducted to further clarify the impact of the initial market proportion and three variables used in the model. The results show that the initial market proportion affects the evolution speed but does not affect the evolution result when the three group players all choose a mixed strategy. For governments, they should not hastily cancel price subsidies provided to consumers; rather, they should dynamically adjust the rate of the subsidy decrease and increase the consumers’ extra cost for purchasing fuel vehicles (FVs). NEV enterprises should appropriately increase their investments in the research and development (R&D) of NEVs.


2011 ◽  
Vol 52 (5) ◽  
pp. 433-440 ◽  
Author(s):  
Sanjeev Sockalingam ◽  
Diana Blank ◽  
Abdulqader Al Jarad ◽  
Fahad Alosaimi ◽  
Gideon Hirschfield ◽  
...  

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