Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 58
Filter
1.
Applied Economics ; : 1-13, 2022.
Article in English | Web of Science | ID: covidwho-1937500

ABSTRACT

This paper investigates the effects of trade regionalism in East Asia from 1995 to 2018, by applying a series of gravity models. An initial, basic gravity model is repeatedly augmented to account for a range of economic, geographical, cultural, and above all institutional factors representing free trade agreements in effect. Unlike previous studies, this investigation distinguishes between the bilateral and multilateral measures of regional trading arrangements. Two interesting findings are reported. First, the results confirm the impact of trade regionalism on the export flows between the economies of East Asia in the period under study. Second, the effects of multilateral trading agreements vary greatly depending on the agreement and on the particular country's range of influence, in particular cases showing no sufficient economic benefits. Overall, the results point to the complementarity of bilateral and multilateral trading arrangements in the region and to the emergence of a certain distinctive model of cooperation and integration in East Asia - which has been underpinned during the COVID-19 pandemic by the conclusion of the Regional Comprehensive Economic Partnership (RCEP), and which will be further verified in the post-COVID character of global trade and regional trading arrangements.

2.
Obstetrics and Gynecology ; 139(SUPPL 1):87S, 2022.
Article in English | EMBASE | ID: covidwho-1925191

ABSTRACT

INTRODUCTION: Pregnant women are at increased risk of severe disease with COVID-19. Despite strong recommendations from ACOG and the Society for Maternal-Fetal Medicine for vaccination, COVID-19 vaccination hesitancy persists. With this study, we aim to evaluate opinions about the COVID-19 vaccine in a cohort of high-risk pregnant patients. METHODS: Institutional review board approval was obtained. Patients attending a regional Maternal-Fetal Medicine clinic were surveyed about the COVID-19 vaccine using a standardized questionnaire. Demographic, obstetrical, and medical information were ed using medical records. The vaccinated and unvaccinated groups were evaluated using student t-tests and a hierarchical Bayesian logistic regression. RESULTS: Among the 157 participants, 38.2% received the vaccine. There were no significant differences between the groups in age, BMI, employment, race and ethnicity, gestational age, or gravity. There was no correlation with influenza or Tdap vaccination rates, nor tobacco or alcohol use. Education level was negatively correlated with vaccination status and had the largest effect size. Those with education at or less than eighth grade level were least likely to be vaccinated (95% CI, 24.46 to 20.41). Those with children in the home were less likely to be vaccinated (95% CI, 21.36 to 20.59). Unvaccinated patients chose lack of data in pregnancy (66%) as their primary concern. Most patients prefer to learn about vaccines via conversation with their doctor (46.7% for vaccinated and 59.8% for unvaccinated). CONCLUSION: The vaccination rate is low in our population. A provider-initiated conversation about COVID-19 vaccination included with routine prenatal care could increase the vaccination rate.

3.
International Journal of Simulation and Process Modelling ; 18(1):23-35, 2022.
Article in English | Scopus | ID: covidwho-1923730

ABSTRACT

The purpose of this study is to model, map, and identify why some areas present a completely different dispersion pattern of COVID-19, as well as creating a risk model, composed of variables such as probability, susceptibility, danger, vulnerability, and potential damage, that characterises each of the defined regions. The model is based on a risk conceptual model proposed by Bachmann and Allgower in 2001, based on the wildfire terminology, analysing the spatial distribution. Additionally, a model based on population growth, chaotic maps, and turbulent flows is applied in the calculation of the variable probability, based on the work of Bonasera (2020). The results for the Portuguese case are promising, regarding the fitness of the said models and the outcome results of a conceptual model for the epidemiological risk assessment for the spread of coronavirus for each region. © 2022 Inderscience Enterprises Ltd.. All rights reserved.

4.
2nd International Conference on Computer Science and Engineering, IC2SE 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1922619

ABSTRACT

Cleanliness is the most important thing. Especially in the conditions of the COVID-19 pandemic that hit almost all parts of Indonesia. But in reality, the problem of garbage accumulation is always present from year to year, and until now it has not been resolved. Batam City Government also has concern for waste banks so that the government has facilitated waste banks so that inorganic waste can be reused and no buildup causes unwanted impacts from piles of garbage. Currently, the points of accumulation of inorganic waste are not balanced, there are locations where there are too many landfills and some are mediocre due to ineffective location placement. So it is necessary to determine the best location in determining the distribution location of the waste bank. To overcome this, the researchers tried to find a way to find the right location using the gravity method seen from the coordinates via Google Maps in an area based on the address of the waste bank and the number of piles of garbage. The results of the study stated that the center of the waste bank should be in the area around the coordinates of 1°02'70.4"N 103°96'15.0"E, Sekupang District. © 2021 IEEE.

5.
Studies in Systems, Decision and Control ; 435:341-363, 2022.
Article in English | Scopus | ID: covidwho-1919595

ABSTRACT

In recent years, palm oil has been established as the most-produced oilseed oil in the world—its production volume has increased from 41 million tons in the 2007/08 season to more than 76 million tons in the 2018/19 season—and a crucial part of the Latin American agro-industrial sector. However, following a slowdown in export growth due to the 2020 COVID-19 lockdown, there is a vital need for sustainable expansion alternatives such as the production of value-added oil-palm products. This chapter presents the business process integration methodology and strategies pursued by a palm oil producer in Peru to optimize the vertical growth of its operational processes within the Latin American palm oil agro-industrial sector, based on the SAP S/4Hana Business Modules: Materials Management (for purchasing), Production Planning (for making), Sales and Distribution (for selling), Controlling (for tracking) and Human Capital Management (for managing staff). © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

6.
Int J Health Plann Manage ; 2022 Jul 01.
Article in English | MEDLINE | ID: covidwho-1919283

ABSTRACT

The COVID-19 has heightened the focus of medical services. Scientifically evaluating the efficiency of medical services and defining their spatial transmission relationship is crucial for the rational allocation of health resources and the accomplishment of balanced regional medical service growth. We used a Stochastic Frontier Model to calculate medical service performance in Chinese provinces and the Gravity Model to study the spatial relationship of medical service performance across provinces using data from 2009 to 2018. We discover that: (1) population density and proportion of technical personnel are significantly positively correlated with the efficiency of regional medical services, whereas health institution density has a significantly negative influence. Their respective influence coefficients were 1.717, 0.647, and 0.407. (2) In China, the regional development of medical service efficiency is unbalanced. The east, middle, and west multi-year average medical service efficiency were 0.65, 0.46, and 0.53, respectively, and their gaps were narrowing; the south and north average efficiency were 0.591, 0.516, respectively, and their gaps were widening. (3) Our medical efficiency network is not yet widespread in the country. Hubei, Henan, Shandong, Jiangsu, Zhejiang, and Beijing were at the centre of the medical efficiency network, driving and connecting the nation's medical service. Our findings offer specific recommendations for better understanding and improving the efficiency of medical services.

7.
International Journal of Advanced and Applied Sciences ; 9(6):90-95, 2022.
Article in English | Web of Science | ID: covidwho-1918248

ABSTRACT

This paper uses the modified gravity model to measure the intensity of tourism economic connection in 11 prefecture-level cities in Shanxi Province from 2016 to 2020. From the perspective of the social network, the density and core-periphery area of the tourism economic network's spatial structure are explored. The research shows that: From 2016 to 2020, the overall tourism economic connection in Shanxi Province shows a growing trend, and the differentiation phenomenon between the central region and the southern and northern regions is more obvious. There is an unbalanced spatial structure of the tourism economy in all prefecture-level cities in Shanxi province. On the whole, the network density shows a growing trend. The various indexes of Taiyuan, the capital city of Shanxi Province, are obviously better than other cities' indexes. The number of core areas of the tourism economy changes little. These areas are closely connected but the strengthening trend is not obvious. The relations within the periphery region are not strong, and the connection between the periphery region and the core region is also weak. The connection of the regional tourism economy is strongly dependent on tourism resources endowment and transportation accessibility. The spatial structure of the tourism economy network is under the great influence of policy suggestions and planning. This study provides a certain theoretical basis for the formulation of tourism economic development strategy in Shanxi Province. The limitation is that the impact of COVID-19 on tourism development has not been specifically analyzed. (C) 2022 The Authors. Published by IASE.

8.
Organizations and Markets in Emerging Economies ; 13(1):139-162, 2022.
Article in English | Web of Science | ID: covidwho-1918180

ABSTRACT

In this paper I apply the gravity model to analyse structural changes of Lithuania's export during the first pandemic year. Lithuania was selected as a case of a small open economy with relatively high numbers of Covid-19 cases, on one hand, and a rather small decrease of its GDP growth in 2020, on the other. The research aims to fill the gap in the current literature by investigating heterogeneity in the goods export in terms of both product groups and export destinations*. I also analyse whether the importance of distance and other export determining factors changed during the pandemic year. Results suggest that Lithuania's export is resilient to economic shocks. Although the effects of Covid-19 were heterogeneous, the pandemic year had only a negligible impact on Lithuania's export structure. The influence of distance or other export determinants on Lithuania's export structure did not change during 2020.

9.
Nephrology Dialysis Transplantation ; 37(SUPPL 3):i695, 2022.
Article in English | EMBASE | ID: covidwho-1915791

ABSTRACT

BACKGROUND AND AIMS: COVID-19 is a life-threatening infection among elderly, comorbid patients or transplanted patients. In our recently published paper (Campise, M.;Alfieri, C.M.;et al. Pathogens 2021, 10, 964), we described our single Centre experience with 82 adult kidney-transplant patients (KTxp) with COVID-19 infection during the previous two pandemic outbreaks: 27 KTxp (first outbreak) and 65 (second). We observed a relatively low and possibly underestimated incidence of infection (5.1%) with a incidence of death almost four times higher than in general population (13%). The availability of COVID-19 vaccines has undoubtedly changed the outcome of the infection in both immunocompetent and immunosuppressed patients. Aim of this second ongoing observational and descriptive study, is to evaluate if the vaccination performed extensively among our KTxp, has modified the incidence and gravity of COVID-19 infection. METHOD: Data on KTxp with COVID-19 infection (COV+) from the 29 October 2021 to 31 December 2021 were collected. Particularly, we focused our anthropometric, clinical and therapeutic aspects. In the statistical analyses, continuous variables were expressed as median and interquartile range (25%-75%), and nominal variables were reported as percentage of cases. RESULTS: From the 29 October 2021 to the 31 December 2021, 33 KTxp developed COVID-19 infection, 60% were male. Median age was 50[29-58] years. Transplant vintage was 57[27-163] months. Median serum creatinine was 1.30[1.0-1.9] mg/dL and body mass index was 23[21-28] kg/m2. Immunosuppressive schedule included: CNI inhibitors, steroids and mycophenolate (MMF) in 97-90 and 70% of COV + respectively. In 50% of cases native vitamin D supplementation was present, whereas only 30% of cases were treated with renin-angiotensin inhibitors. Only one had insulin dependent diabetes. At the moment of nasopharyngeal swab positivity 64% of COV + had already received three doses of vaccine (Comirnaty (BNT162b2)®) and 30% 2 doses. Only 3% of pts had received a single dose. One patient had refused vaccination for personal reasons. Antigenic nasopharyngeal swab was performed in 70% of COV + and molecular swab in 60%. Thirty-five % of COV + were tested with both methods. The most frequent symptoms were: fever (70%), cough (75%) and headache (40%). In the previous outbreaks dyspnea was present in 33% of cases dropping to 13% in this cohort. Smell and taste alteration were present in 25% and 28% respectively. We did not perform the COVID-19 sequence. But, on the base of the symptoms referred, we are confident that 17 patients had delta variant and remaining had omicron. The first therapeutic approaches were the increase of the daily steroid dosage up to 25 mg (60% of cases) together with MMF temporarily withdrawing in 70% of cases and halving in 10%. Forty % of pts were also treated with monoclonal antibodies (Ronapreve®) upon infectious disease specialist evaluation. During the first two outbreaks, hospitalization was necessary in 45% of cases, and 13% of pts died. In the present cohort only 10% of patients required oxygen support and hospitalization. Nobody died. CONCLUSION: Although very preliminary, our results indicate that the vaccination campaign has noticeably ameliorated the incidence, the clinical presentation and the outcome of COVID-19 in KTxp. This comforting data should further sensitize the medical community on vaccination counseling in KTxp as soon as possible. Study with higher number of patients are needed to further clarify the individual response on antibody production and sensitivity to this still life-threatening infection.

10.
Annals of Tourism Research ; 95:103440, 2022.
Article in English | ScienceDirect | ID: covidwho-1914140

ABSTRACT

This study investigated whether regional differences in economic, socio-psychological, and environmental distance affect tourists' destination choices. Taking Hangzhou, China, as a case, macro- and micro-level data were integrated to examine the effects of multi-dimensional distance on the city's tourism demand via a panel gravity model. All six distance variables were identified as influencing factors, but their effects varied in size and direction. Tourists' behavior has changed since COVID-19;as such, distance effects before and after its emergence were identified. Tourists were less sensitive to economic distance and price differences following the pandemic and tended to favor more culturally and climatically different destinations. The terror management theory was introduced to explain the shift in tourists' choices. Findings provide implications for destination management and marketing amid the pandemic.

11.
Exp Physiol ; 2021 Jul 09.
Article in English | MEDLINE | ID: covidwho-1909549

ABSTRACT

NEW FINDINGS: What is the topic of this review? The use of proning for improving pulmonary gas exchange in critically ill patients. What advances does it highlight? Proning places the lung in its 'natural' posture, and thus optimises the ventilation-perfusion distribution, which enables lung protective ventilation and the alleviation of potentially life-threatening hypoxaemia in COVID-19 and other types of critical illness with respiratory failure. ABSTRACT: The survival benefit of proning patients with acute respiratory distress syndrome (ARDS) is well established and has recently been found to improve pulmonary gas exchange in patients with COVID-19-associated ARDS (CARDS). This review outlines the physiological implications of transitioning from supine to prone on alveolar ventilation-perfusion ( V ̇ A -- Q ̇ ) relationships during spontaneous breathing and during general anaesthesia in the healthy state, as well as during invasive mechanical ventilation in patients with ARDS and CARDS. Spontaneously breathing, awake healthy individuals maintain a small vertical (ventral-to-dorsal) V ̇ A / Q ̇ ratio gradient in the supine position, which is largely neutralised in the prone position, mainly through redistribution of perfusion. In anaesthetised and mechanically ventilated healthy individuals, a vertical V ̇ A / Q ̇ ratio gradient is present in both postures, but with better V ̇ A -- Q ̇ matching in the prone position. In ARDS and CARDS, the vertical V ̇ A / Q ̇ ratio gradient in the supine position becomes larger, with intrapulmonary shunting in gravitationally dependent lung regions due to compression atelectasis of the dorsal lung. This is counteracted by proning, mainly through a more homogeneous distribution of ventilation combined with a largely unaffected high perfusion dorsally, and a consequent substantial improvement in arterial oxygenation. The data regarding proning as a therapy in patients with CARDS is still limited and whether the associated improvement in arterial oxygenation translates to a survival benefit remains unknown. Proning is nonetheless an attractive and lung protective manoeuvre with the potential benefit of improving life-threatening hypoxaemia in patients with ARDS and CARDS.

12.
Expert Systems with Applications ; 205, 2022.
Article in English | Scopus | ID: covidwho-1889400

ABSTRACT

Many studies propose methods for finding the best location for new stores and facilities, but few studies address the store closing problem. As a result of the recent COVID-19 pandemic, many companies have been facing financial issues. In this situation, one of the most common solutions to prevent loss is to downsize by closing one or more chain stores. Such decisions are usually made based on single-store performance;therefore, the under-performing stores are subject to closures. This study first proposes a multiplicative variation of the well-known Huff gravity model and introduces a new attractiveness factor to the model. Then a forward–backward approach is used to train the model and predict customer response and revenue loss after the hypothetical closure of a particular store from a chain. In this research the department stores in New York City are studied using large-scale spatial, mobility, and spending datasets. The case study results suggest that the stores recommended being closed under the proposed model may not always match the single store performance, and emphasizes the fact that the performance of a chain is a result of interaction among the stores rather than a simple sum of their performance considered as isolated and independent units. The proposed approach provides managers and decision-makers with new insights into store closing decisions and will likely reduce revenue loss due to store closures. © 2022 Elsevier Ltd

13.
The North American Journal of Economics and Finance ; 62:101719, 2022.
Article in English | ScienceDirect | ID: covidwho-1886004

ABSTRACT

Real interest rates have fallen dramatically since the early 1980s. Economic theory states that lower real rates discourage savings while promoting spending. However, today, in the world economy, we face a global saving glut problem in which, even in negative real rates, economic agents keep saving. This situation leads to excess demand for safe assets (US Treasuries), lower bond yields, and higher equity valuations. Thus, the world economy has become more dependent on major economies, especially the United States. In this research, we aim to measure the dependency of the world economy on United States monetary policy. We called this new methodology “financial gravity” and tried to quantify the nature by using panel data analysis. We define monetary dependency (financial gravity) by US Investment flows and their reaction against International Reserves, Credit Default Spreads (CDS), and Foreign Exchange Rates. Our empirical findings support that financial gravity is positively related to international reserves and negatively related to Credit Default Swap Spreads (CDS) and Foreign Exchange rates. We also analyzed the COVID-19 period and found that pandemics positively contributed to world reserve accumulation due to economic lock-down measures, fiscal stimulus packages (unemployment benefits), and decreased global spending.

14.
Revue Medicale Suisse ; 17(726):334-337, 2021.
Article in French | EMBASE | ID: covidwho-1885057

ABSTRACT

Children appeared to be initially spared by the SARS-CoV-2 pandemic, however, in spring 2020, a new clinical entity was described related to the SARS-CoV-2 infection and named multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome (PIMS). The gravity of this inflammatory syndrome, the time interval between infection and MIS-C, the response to the various immunomodulatory treatments are all suggestive of an immunologic reaction rather than a virus-mediatred phenomenon. The pathophysiological mechanisms and possible risk factors for MIS-C have not been elucidated. In this article, we summarize what is known to date about the immune response to SARS-CoV-2 in children and about the immune response to SARSCoV-2 in children and about the MIS-C.

15.
World Econ ; 2022 Jun 23.
Article in English | MEDLINE | ID: covidwho-1868700

ABSTRACT

Given the importance of services for economic activity in general and the salience of reducing service link costs for overcoming the economic and health challenges emanating from COVID-19, we examine the effect of the pandemic on services trade in the original group of ASEAN+6 countries that began negotiating the RCEP agreement. Stylised facts show that ASEAN+6 commercial services' exports and imports declined by 19.7% and 22.1%, respectively, on a YoY basis during 2020, with considerable heterogeneity across countries and sectors. ASEAN+6 announced greenfield investment in services also fell by a third during 2020, with the intra-ASEAN+6 decline being more severe at 41.8%. Meanwhile, structural gravity estimates suggest that the stringency of containment measures imposed in the wake of the pandemic may have reduced ASEAN+6 services exports by 61.6%.

16.
Operations and Supply Chain Management ; 15(2):205-217, 2022.
Article in English | Scopus | ID: covidwho-1848104

ABSTRACT

A key strategy to winning the war against the COVID-19 pandemic involves acquiring sufficient vaccination coverage of the population to attain herd immunity. Such a task is highly daunting for many countries, especially for those whose significant portions of the population have limited access to vaccination services. One way to overcome this challenge is by implementing an outreach program, which involves setting up new outreach sites in remote and sparsely populated areas to improve the vaccination access for people residing there. This paper presents a novel approach to the planning of such outreach sites systematically and optimally. Our approach comprises a two-step Greenfield Analysis (GFA) procedure implemented using supply chain design software. The first step involves the design of the vaccination network to find the number and location of outreach sites that maximize the vaccination coverage for people residing within a threshold distance from the outreach sites. This is followed by the design of the vaccine supply network between the health centers and the outreach sites to determine the required vaccine doses that need to be kept at the vaccination sites. The required number of vaccinators and their ancillary supply kits can also be determined accordingly based on the supply network. We have tested our approach on a case study involving the COVID-19 vaccination scheme for Bali Province in Indonesia. We obtained the optimal number and locations of outreach sites for each regency in Bali and the whole province. © 2022 Operations and Supply Chain Management Forum. All rights reserved.

17.
J Clin Med ; 11(9)2022 May 01.
Article in English | MEDLINE | ID: covidwho-1847353

ABSTRACT

Hand movements are particularly impaired in patients with Parkinson's Disease (PD), contributing to functional disability and difficulties in activities of daily living. Growing evidence has shown that robot-assisted therapy may be considered an effective and reliable method for the delivery of the highly repetitive training that is needed to trigger neuroplasticity, as intensive, repetitive and task-oriented training could be an ideal strategy to facilitate the relearning of motor function and to minimize motor deficit. The purpose of this study is to evaluate the improvement of hand function with semi-autonomous exercises using an upper extremity exoskeleton in patients with PD. A multicenter, parallel-group, randomized clinical trial was then carried out at the IRCCS Centro Neurolesi Bonino-Pulejo (Messina, Italy). Thirty subjects with a diagnosis of PD and a Hoehn-Yahr score between 2 and 3 were enrolled in the study. Patients were 1:1 randomized into either the experimental group (ERT), receiving 45 min training daily, 6 days weekly, for 8 weeks with Armeo®Spring (Volketswil, Switzerland) (a gravity-supporting device), or the control group (CPT), which was subjected to the same amount of conventional physical therapy. Motor abilities were assessed before and after the end of the training. The main outcomes measures were the Nine-hole peg test and the motor section of the UPDRS. All patients belonging to ERT and 9 out of 15 patients belonging to the CPT completed the trial. ERT showed a greater improvement in the primary outcome measure (nine-hole peg test) than CPT. Moreover, a statistically significant improvement was found in ERT concerning upper limb mobility, and disease burden as compared to CPT. Using an upper extremity exoskeleton (i.e., the Armeo®Spring) for semi-autonomous training in an inpatient setting is a new perspective to train patients with PD to improve their dexterity, executive function and, potentially, quality of life.

18.
IOP Conference Series. Earth and Environmental Science ; 1015(1):012014, 2022.
Article in English | ProQuest Central | ID: covidwho-1830933

ABSTRACT

The COVID-19 pandemic influences human health and activities in many regions in Indonesia. East Java is an area with high community interaction, and mobility is one of the provinces that implements a regional restriction policy. The people mobility among regions makes it necessary to control the people interaction during the pandemic. The regional restriction strategy is one way to reduce and avoid the spread of COVID-19 in the Surabaya Metropolitan Area (Surabaya, Gresik, and Sidoarjo). This study aims to assess the COVID-19 control policy based on the interaction of activities between regions. The analysis uses a projected model of the spread of COVID-19 and a spatial interaction model based on the spread pattern of COVID-19 in the Surabaya Metropolitan Area. The research variables consisted of the health facilities, population, case data in a certain period, positive case data, patient treatment, and road network. The data were analyzed using the SurgeCDC Model and the Gravity Model furthermore. The results of the study provide the effectiveness of the policies to be carried out, predictions of the end of the pandemic in an area, descriptions of cases when using policy interventions, and conditions of spatial interaction. There needs to be an anticipation of the demand for health facilities such as medical personnel, medicine, and care rooms.

19.
Vet Sci ; 9(5)2022 Apr 28.
Article in English | MEDLINE | ID: covidwho-1820458

ABSTRACT

The continuous threat of foreign animal disease (FAD) is real and present for the U.S. swine industry. Because of this, the industry has developed plans to ensure business continuity during a FAD outbreak. A core aspect of these plans is regional standstill orders of swine movements to prevent disease spread following a FAD introduction. Unfortunately, there is a dearth of information about the impact of such practices on animal movements throughout the remaining swine marketing channel. This study utilizes a simplified gravity model, to understand the effects of standstill orders on individual states. The effect of each closure on the established trade patterns is determined by monitoring changes in a PPML regression coefficients of the model. Model validation compared the predicted impact of the closure of a terminal processing facility against a real-life closure dataset collected during the SARS-CoV-2 pandemic. The analysis determined that both the population size and location of the closure affected the observed trade patterns. These findings suggest that using a regional stop movement order may complicate disease introduction preparation as each policy comes with its own potential outcome, shifting the geospatial distribution of area risk posed by these cull populations.

20.
ISPRS International Journal of Geo-Information ; 11(4):267, 2022.
Article in English | ProQuest Central | ID: covidwho-1809936

ABSTRACT

The cross-impact of environmental pollution among cities has been reported in more research works recently. To implement the coordinated control of environmental pollution, it is necessary to explore the structural characteristics and influencing factors of the PM2.5 spatial correlation network from the perspective of the metropolitan area. This paper utilized the gravity model to construct the PM2.5 spatial correlation network of ten metropolitan areas in China from 2019 to 2020. After analyzing the overall characteristics and node characteristics of each spatial correlation network based on the social network analysis (SNA) method, the quadratic assignment procedure (QAP) regression analysis method was used to explore the influence mechanism of each driving factor. Patent granted differences, as a new indicator, were also considered during the above. The results showed that: (1) In the overall network characteristics, the network density of Chengdu and the other three metropolitan areas displayed a downward trend in two years, and the network density of Wuhan and Chengdu was the lowest. The network density and network grade of Hangzhou and the other four metropolitan areas were high and stable, and the network structure of each metropolitan area was unstable. (2) From the perspective of the node characteristics, the PM2.5 spatial correlation network all performed trends of centralization and marginalization. Beijing-Tianjin-Hebei and South Central Liaoning were “multi-core” metropolitan areas, and the other eight were “single-core” metropolitan areas. (3) The analysis results of QAP regression illustrated that the top three influencing factors of the six metropolitan areas were geographical locational relationship, the secondary industrial proportion differences, respectively, and patent granted differences, and the other metropolitan areas had no dominant influencing factors.

SELECTION OF CITATIONS
SEARCH DETAIL