81 research outputs found
The impact of monetary policy shocks on income inequality: a tale of two countries
The easing monetary policy after the global financial crisis triggered
wide concerns on the responses of income inequality. In this paper,
we investigate impact of monetary policy shocks on income inequality.
We propose a general equilibrium model and show that monetary
policies could affect income inequality by affecting the earnings
of high-income households in financial markets and business operations.
Using a TVP-FAVAR model, we find contradictory distributional
effects of monetary policy shocks in China and the US. Specifically,
expansionary monetary policy shocks persistently increase income
inequality in China but decrease income inequality in the US.
Moreover, the impacts are volatile in the short-term, but stabilise
after 10 periods. The investigation on the responses of top 1% and
bottom 50% income share confirms the finding of contradictory distributional
effects of monetary policy shocks
Stochastic Constrained DRO with a Complexity Independent of Sample Size
Distributionally Robust Optimization (DRO), as a popular method to train
robust models against distribution shift between training and test sets, has
received tremendous attention in recent years. In this paper, we propose and
analyze stochastic algorithms that apply to both non-convex and convex losses
for solving Kullback Leibler divergence constrained DRO problem. Compared with
existing methods solving this problem, our stochastic algorithms not only enjoy
competitive if not better complexity independent of sample size but also just
require a constant batch size at every iteration, which is more practical for
broad applications. We establish a nearly optimal complexity bound for finding
an stationary solution for non-convex losses and an optimal
complexity for finding an optimal solution for convex losses.
Empirical studies demonstrate the effectiveness of the proposed algorithms for
solving non-convex and convex constrained DRO problems.Comment: 37 pages, 16 figure
An Integrated Approach for Assessing Aquatic Ecological Carrying Capacity: A Case Study of Wujin District in the Tai Lake Basin, China
Aquatic ecological carrying capacity is an effective method for analyzing sustainable development in regional water management. In this paper, an integrated approach is employed for assessing the aquatic ecological carrying capacity of Wujin District in the Tai Lake Basin, China. An indicator system is established considering social and economic development as well as ecological resilience perspectives. While calculating the ecological index, the normalized difference vegetation index (NDVI) is extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) time-series images, followed by spatial and temporal analysis of vegetation cover. Finally, multi-index assessment of aquatic ecological carrying capacity is carried out for the period 2000 to 2008, including both static and dynamic variables. The results reveal that aquatic ecological carrying capacity presents a slight upward trend in the past decade and the intensity of human activities still exceeded the aquatic ecological carrying capacity in 2008. In terms of human activities, population has decreased, GDP has quadrupled, and fertilizer application and industrial wastewater discharge have declined greatly in the past decade. The indicators representing aquatic ecosystem conditions have the lowest scores, which are primarily attributed to the water eutrophication problem. Yet the terrestrial ecosystem is assessed to be in better condition since topographic backgrounds and landscape diversity are at higher levels. Based on the work carried out, it is suggested that pollutant emission be controlled to improve water quality and agricultural development around Ge Lake (the largest lake in Wujin District) be reduced
Effect of institutional quality and foreign direct investment on economic growth and environmental quality: evidence from African countries
This study applies the method of the fully modified ordinary least
squares (FMOLS) method and the vector error correction model
(VECM) to explore whether institutional quality (IQ) and foreign
direct investment (FDI) promoted economic growth (EG) and
environmental quality (EQ) in oil-producing and non-oil-producing
African countries from 1999 to 2017. The FMOLS findings demonstrate that IQ significantly promoted EG and improved EQ in the
non-oil-producing countries, however it only improved EQ and
showed no significant impact on EG in oil-producing countries.
FDI significantly promoted EG to a higher extent in oil-producing
countries than in non-oil-producing countries, but it presented no
significant impact on EQ in both groups. The VECM results reveal
that (i) two-way causation among IQ and EG, IQ and EQ, FDI and
EG, and FDI and EQ was occurred in both groups, in the long-run.
(ii) two-way causation among FDI and EQ and one-way causation
from FDI to EG was observed in non-oil-producing countries in
the short-run. Moreover, two-way causation among IQ and EG,
and one-way causation from IQ to EQ were observed in non-oilproducing countries. To realize the sustainable development of
economy and environment, a series of policy suggestions have
been discussed
Pharmacodynamics, metabolomics and pathological studies on mechanisms of traditional benefits of Angelica sinensis in blood circulation
Angelica sinensis is a rich source of medically important active molecules that need in-depth understanding on its action mechanisms. Therefore, through pharmacodynamics, metabolomics, and network pharmacology, the traditional benefits of A. sinensis in blood circulation was studied using 24 randomly selected Sprague-Dawley (SD) rats. Measurement of the blood rheological parameters for whole blood viscosity (WBV) and plasma viscosity (PV), and inspection of the heart and lung tissues pathological changes were undertaken using molecular and bioinformatic techniques. Multivariate statistical analysis and establishment of the model of the relationship between metabolite expression and sample categories to test the prediction of sample categories were performed. Screening was undertaken to find the potential metabolites for A. sinensis to treat blood stasis syndrome and find related metabolic pathways. Active ingredients of A. sinensis and targets and building of an “effect component-target” network was undertaken, A. sinensis was confirmed to improve blood stasis syndrome in rats and improve heart and lung pathology to varying degrees. Compared with the blood stasis model group, A. sinensis significantly reduced WBV and PV in hemorheology (p<0.05, p<0.01) and regulated blood stasis-induced changes in 22 metabolites including alpha-D-glucose, L-isoleucine, creatine and acetylcarnitine, which are involved in the metabolism of linoleic acid, linolenic acid, phenylalanine, ascorbic acid and uronic acid. Using the network pharmacology to build a "component-target-pathway" network of A. sinensis, 62 active ingredients, 169 active proteins and 18 metabolic pathways were obtained, among which linoleic acid metabolism, ascorbic acid and uronic acid metabolism were consistent with the metabolic pathways obtained by metabolomics
The Characteristics, Long-Term Outcomes, Risk Factors, and Antithrombotic Therapy in Chinese Patients With Atrial Fibrillation and Bioprosthetic Valves
Introduction: There were few data about the clinical profiles and long-term outcomes in Chinese patients with atrial fibrillation (AF) and bioprosthetic valves.Methods: The retrospective study enrolled 903 patients with bioprosthetic valve replacement at our hospital and discharged with a diagnosis of AF from January 2010 to December 2018.Results: The median age was 65.6 (61.9–69.1) years, and 548 (60.7%) patients were women. During a follow-up period of 3.84 (2.64–5.51) years, 68 (1.8 per 100 person-years) patients died, 81 (2.1 per 100 person-years) patients developed thromboembolism, and 23 (0.6 per 100 person-years) patients experienced major bleeding. The CHA2DS2-VASc score, as a categorical variable (low, moderate, or high risk), predicted the risk of thromboembolism with the C-statistic of 0.6 (95% CI: 0.511–0.689, p = 0.046). The incidence of the CHA2DS2-VASc score increment was 11.6 per 100 person-years, and the annual reclassification rate of stroke risk (from a low or moderate group to a higher group) was 12.7%. The current proportion of oral anticoagulants was 52.3, 59, and 63.2%, respectively, in the low, moderate, and high stroke risk groups. Age (OR: 1.04, 95% CI: 1.01–1.06, p = 0.01), left atrial size (OR: 1.05, 95% CI: 1.03–1.08, p < 0.001), and rheumatic heart disease (OR: 1.49, 95% CI: 1.05–2.10, p = 0.025) were positively associated with the use of oral anticoagulants. The history of chronic kidney disease (OR: 0.20, 95% CI: 0.05–0.76, p = 0.018), prior surgical ablation (OR: 0.33, 95% CI: 0.24–0.47, p < 0.001), and antiplatelet agent use (OR: 0.08, 95% CI: 0.05–0.13, p < 0.001) were inversely related to the use of oral anticoagulants. Higher admission estimated glomerular filtration rate (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01), left ventricular ejection fraction (HR: 0.961, 95% CI: 0.931–0.992, p = 0.014), concomitant surgical ablation (HR: 0.348, 95% CI: 0.171–0.711, p = 0.004), and rheumatic heart disease history (HR: 0.515, 95% CI: 0.311–0.853, p = 0.01) were associated with a lower risk of death. Surgical ablation (HR: 0.263, 95% CI: 0.133–0.519, p < 0.001) and oral anticoagulants (HR: 0.587, 95% CI: 0.375–0.918, p = 0.019) were related to a lower risk of thromboembolism.Conclusion: Chinese patients with AF and bioprosthetic valve(s) were relatively young and had a high prevalence of rheumatic heart disease with few comorbidities. The percentage of mitral bioprosthetic valve replacement was high. The proportion of concomitant surgical ablation or surgical left atrial appendage occlusion or exclusion was relatively low. The thromboembolic events were the major long-term adverse events. The anticoagulation therapy was underused in patients at moderate or high stroke risk. The CHA2DS2-VASc score was verified to be used for predicting stroke risk in this population. The stroke risk dynamically changed; it needed to be reestimated once the risk factor changed
Fault location in a marine low speed two stroke diesel engine using the characteristic curves method
When a malfunction occurs in a marine main engine system, the impact of the anomaly will propagate through the system, affecting the performance of all relevant components in the system. The phenomenon of fault propagation in the system caused by induced factors can interfere with fault localization, making the latter a difficult task to solve. This paper aims at showing how the "characteristic curves method" is able to properly locate malfunctions also when more malfunctions appear simultaneously. To this end, starting from the working principle of each component of a real marine diesel engine system, comprehensive and reasonable thermal performance parameters are chosen to describe their characteristic curves and include them in a one-dimensional thermodynamic model. In particular, the model of a low-speed two stroke MAN 6S50 MC-C8.1 diesel engine is built using the AVL Boost software and obtaining errors lower than 5% between simulated values and test bench data. The behavior of the engine is simulated considering eight multi-fault concomitant phenomena. On this basis, the fault diagnosis method proposed in this paper is verified. The results show that this diagnosis method can effectively isolate the fault propagation phenomenon in the system and quantify the additional irreversibility caused by the Induced factors. The fault diagnosis index proposed in this paper can quickly locate the abnormal components
DeePMD-kit v2: A software package for Deep Potential models
DeePMD-kit is a powerful open-source software package that facilitates
molecular dynamics simulations using machine learning potentials (MLP) known as
Deep Potential (DP) models. This package, which was released in 2017, has been
widely used in the fields of physics, chemistry, biology, and material science
for studying atomistic systems. The current version of DeePMD-kit offers
numerous advanced features such as DeepPot-SE, attention-based and hybrid
descriptors, the ability to fit tensile properties, type embedding, model
deviation, Deep Potential - Range Correction (DPRc), Deep Potential Long Range
(DPLR), GPU support for customized operators, model compression, non-von
Neumann molecular dynamics (NVNMD), and improved usability, including
documentation, compiled binary packages, graphical user interfaces (GUI), and
application programming interfaces (API). This article presents an overview of
the current major version of the DeePMD-kit package, highlighting its features
and technical details. Additionally, the article benchmarks the accuracy and
efficiency of different models and discusses ongoing developments.Comment: 51 pages, 2 figure
Spatiotemporal Distribution and Driving Factors of Forest Biomass Carbon Storage in China: 1977–2013
Increasing forest vegetation is important for carbon dynamics and to maintain the ecological and environmental balance in China. However, there is little understanding of how socioeconomic factors affect forest biomass carbon storage (FBCS). Here, we used continuous functions for biomass expansion factors and China’s seven completed forest inventories to estimate the changes in FBCS for 31 provinces in mainland China between 1977 and 2013. We developed a model that decomposes the contribution of the different socioeconomic factors driving FBCS. We found China’s FBCS increased from 4972 TgC (1 Tg = 1012g) in 1977–1981 to 7435 TgC in 2009–2013, with a mean growth of 77 TgC/a, and the average forest carbon density increased from 36.0 to 38.9Mg/ha (1 Mg = 106g), mainly due to the arbor forest contribution. Among the seven regions in China, the southwestern region currently accounts for the highest proportion (37.3%) of national FBCS, followed by northeastern (19.7%), northern (12.5%) and eastern region (10.8%). The main socio-economic factors affecting FBCS were forest land dependence, industrial structure and economic development level. Optimizing forest type and age structure, improving forest productivity, and strengthening forest management are feasible options to further increase China’s FBCS
Environmental Pollution Liability Insurance Pricing and the Solvency of Insurance Companies in China: Based on the Black–Scholes Model
Environmental pollution liability insurance is becoming increasingly important for China to achieve its emission reduction targets. Insurance pricing is a crucial factor restricting the market share of environment pollution liability insurance, from the perspective of the Black–Scholes pricing model, which in turn has influenced the solvency of insurance companies in China. Firstly, this study analyzes the problems existing in compulsory liability insurance for environmental pollution in China. It proceeds with analyzing the price of compulsory environmental pollution liability insurance using the Black–Scholes pricing model, and derives a high premium insurance rate of 2.44%. Moreover, it performs a multivariate regression analysis using the asset and liability data, taken from the annual report, to identify three key factors affecting the solvency adequacy ratio, namely, capital debt ratio, reflecting the company asset structure; net interest rate on assets, reflecting the asset scale with actual solvency; and claim ratio, reflecting the business quality. Based on the results of regression analysis and robustness test for the China Insurance Clauses (CIC) company, People’s Insurance Company of China (PICC), and Asia-Pacific Property & Casualty Insurance (API) company, it is shown that the effect of total asset, total debt, capital debt ratio, claim ratio, and net interest rate on assets on the solvency adequacy ratio is significant, with respect to the size of the coefficients. Based on the Black–Scholes pricing model found in the previous cycle of liability insurance, and keeping in view the existing problems of environmental pollution liability insurance expenditure, this paper presents suggestions that are conducive to improving the solvency of insurance companies in China
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