Analysis on the impact of vehicle pollutant emission control based on system dynamics

2021 ◽  
Author(s):  
Chen Zhang
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.


Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1604
Author(s):  
Tao Zhu ◽  
Furong Li ◽  
Wenfeng Niu ◽  
Zijun Gao ◽  
Yiwei Han ◽  
...  

Monitoring of toxic and hazardous air pollutants (HAPs) in a petrochemical company in the Beijing-Tianjin-Hebei region of China to assess the impact of HAPs on the health risks of workers in the petrochemical company. The samples were tested by solid-phase adsorption thermal desorption/gas chromatography-mass spectrometry (HJ734-2014), and the pollutant emission list was obtained. According to the pollutant emission inventory, it can be seen that benzene, toluene and xylene are the main components of toxic and harmful air pollutants emitted by the petrochemical enterprise. The method of combining actual monitoring and CALPUFF model prediction was used to evaluate the impact of the toxic and harmful air pollutants emitted by the enterprise on the health of workers. The risk characterization results show that when benzene is the maximum concentration value predicted by the model, it will pose a carcinogenic risk to the factory workers. Therefore, based on the results of this study, it is recommended not to allow residents to live within the predicted concentration range of the model. The results of this study can enable China’s oil refining industry to better understand the characteristics of pollutant emissions from petrochemical companies in the Beijing-Tianjin-Hebei region. Moreover, the results of this study can be used as a policy basis for improving the health of workers in petrochemical enterprises, and are of great significance to the protection of public health.


Author(s):  
Hassan Qudrat-Ullah

System dynamics models can facilitate the understanding of complex and dynamic biomedical systems such as in HIV/AIDS. Untangling the dynamics among various population stocks (e.g., susceptible population, infected population, HIV population, AIDS population) can be used to investigate the effective points of interventions in the HIV/AIDS cycle. With that in mind, the authors have developed a system dynamics model that can be used to examine various policy decisions for the prevention and the treatment of HIV/AIDS. The specific objectives of their study was to examine the growing number of AIDS-related deaths in Canada. They used the authors’ dynamic simulation model to evaluate the impact of various HIV/AIDS policy intervention scenarios centred on the reduction of the number of AIDS deaths in Canada. Their analysis suggests that more lives will be saved if effective preventive and treatment programs are implemented simultaneously. A simultaneous implementation of these programs will also result in a much smaller HIV-infected and AIDS populations.


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