A Timescale Decomposed Threshold Regression Downscaling Approach to Forecasting South China Early Summer Rainfall

A timescale decomposed threshold regression （TSDTR） downscaling approach to forecasting South China early summer rainfall （SCESR） is described by using long-term observed station rainfall data and NOAA ERSST data. It makes use of two distinct regression downscaling models corresponding to the interannual and interdecadal rainfall variability of SCESR. The two models are developed based on the partial least squares （PLS） regression technique, linking SCESR to SST modes in preceding months on both interannual and interdecadal timescales. Specifically, using the datasets in the calibration period 1915-84, the variability of SCESR and SST are decomposed into interannual and interdecadal components. On the interannual timescale, a threshold PLS regression model is fitted to interannual components of SCESR and March SST patterns by taking account of the modulation of negative and positive phases of the Pacific Decadal Oscillation （PDO）. On the interdecadal timescale, a standard PLS regression model is fitted to the relationship between SCESR and preceding November SST patterns. The total rainfall prediction is obtained by the sum of the outputs from both the interannual and interdecadal models. Results show that the TSDTR downscaling approach achieves reasonable skill in predicting the observed rainfall in the validation period 1985-2006, compared to other simpler approaches. This study suggests that the TSDTR approach, considering different interannual SCESR-SST relationships under the modulation of PDO phases, as well as the interdecadal variability of SCESR associated with SST patterns, may provide a new perspective to improve climate predictions.

Tourism dependence and poverty alleviation thresholds in Chinese ethnic tourism

Questions persist on the relationship between tourism dependence and economic growth in ethnic tourism areas.This study addresses such gaps by constructing a threshold regression model based on socio-economic data from 2006 to 2019 for nine sites in Enshi Prefecture of central China.Arc GIS and other open-source data were also used to visualize changing tourism resources in the region.Findings suggest that tourism dependence(the ratio of tourism-based GDP to overall GDP)significantly promotes economic growth in ethnic minority areas.However,the positive influence of tourism dependence on economic growth appears dynamic and non-linear–rising at first before falling when tourism dependence exceeded a threshold of 34%,with effects varying by site and year.Methods and findings make crucial theoretical contributions to understanding tourism dependence and poverty alleviation linkages.This paper also highlights the importance of political support and balanced investment in diverse industries to minimize decreasing returns beyond tourism dependence thresholds in destinations worldwide.

Short Term Load Forecasting Using Subset Threshold Auto Regressive Model

The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is proposed and applied to model and forecast power load. Numerical example verifies that desirable accuracy of short term load forecasting can be achieved by using the SSTAR model.

Regional differences and threshold characters of the impact of energy use efficiency on energy scarcity in China

The improvement of the technical efficiency of energy use has been widely seen as an important way to alleviate energy scarcity.However,the energy rebound effect demonstrates the vulnerability and unsustainability of alleviating energy scarcity relying on technology.Under the background of the consistent development of energy factor market,it is of great importance to explore the paths and differences of energy source allocation constrained by technology and cost to promote the sustainable use of energy.This study analyzed the regional differences and threshold characteristics in the impact of the technical and cost efficiency of energy use on energy scarcity using the instrumental variable-two-stage least square method,based on the panel data of Chinese provinces from 2003 to 2017.The results showed that:①Technology and price were the critical forces of the technical and cost efficiency of energy use.They changed the degree of use of surplus production factors by affecting the complementary and replacement demand relationship between energy and non-energy factors.Meanwhile,the impact of energy use efficiency on energy scarcity showed regional and time features due to the different technology capabilities and different levels of market development in different regions and different time.②The alleviation of energy scarcity at the national level relied on the improvement of energy cost efficiency.At the regional level,the alleviation of energy scarcity in central China came from the improvement of the technical efficiency of energy use.However,the alleviation of energy scarcity in the eastern and western regions was due to the improvement of energy cost efficiency.③Constrained by the economic development,openness,science and technology input and the industrial development structure,the impact of the technical and cost efficiency of energy use on energy scarcity demonstrated a nonlinear feature.And structural mutation occurred after passing a specific‘inflection point’,which showed a significant threshold feature.Therefore,energy price should play an important role in energy use and it is necessary to pay attention to the regional differences and time characteristics of energy economic development to promote the sustainable development of energy resources.

Associations of Time Spent on Study and Sleep with Anxiety and Depressive Symptoms in Junior High School Students:Report from the Large-Scale Monitoring of Basic Education Data in China

In the context of the COVID-19 pandemic and under the pressure of high competitiveness for higher education in China,junior high school students’mental health is facing greater challenges.Understanding the time allocation of study and sleep is necessary for developing effective prevention and treatment programs.Based on a survey of 31,057 junior high school students in 47 junior high schools in Gansu Province,China's Mainland,the study analyzed the associations of time spent on study and sleep with anxiety and depressive symptoms among junior high school students through chi-square test,ANOVA,logistic regression model and threshold regression model.It was found that 18.4%–21.1%of junior high school students had mild and above anxiety and depressive symptoms.Female junior high school students were more likely to have anxiety and depressive symptoms.In addition,time spent on study was significantly and positively associated with anxiety and depressive symptoms and time spent on sleep was significantly and negatively associated with anxiety and depressive symptoms.Late sleepers were more likely to suffer from anxiety and depressive tendencies.Reducing after-school study time appropriately and getting more sleep are beneficial in reducing anxiety and depression,but it is more important to ensure time of sleep.For the reduction of anxiety and depressive symptoms,the maximum time spent on study after school should not exceed 1.92 h,the minimum time spent on sleep at night should be more than 7 h and a 40-min lunch break should be guaranteed at noon.

Poverty Reduction Effects of China’s Aid and Investment to Developing Countries

The Chinese approach to poverty reduction is a government-led and marketbased approach that gives priority to infrastructure and combines fiscal subsidy with development as an antidote to poverty.These characteristics are also evident in China’s cooperation with other developing countries on poverty reduction.China supports other developing countries to reduce poverty via aid and investment mainly in the field of infrastructure.While the government and SOEs take the lead in foreign aid and investment,China also invites other sources of capital to participate in market-based development in partnership with recipient countries.Our empirical research finds that aid and investment from China are generally conducive to reducing poverty incidence in recipient developing countries,but their poverty reduction effects vary across different types of aid and investment.The elements characteristic of the Chinese approach to poverty reduction proved to be effective in helping other developing countries reduce poverty as well.Nevertheless,the effectiveness of aid and investment in reducing poverty is subject to the governance and market efficiency of recipient countries.In order for the Chinese experience to work in less developed countries,future cooperation on poverty reduction must put a premium on governance and market systems.

Mathematical modelling of nonlinear behaviour of seismicity

In this paper,the nonlinear behaviour of seismic activities has been studied by means of the threshold autoregressive model and the exponential autoregressive model. The contents are as follows: ① The theories and modelling methods of this two models have been studied.② One kind of explanation for the seismic cycle and order structure are given by means of the threshold autoregressive model.③ According to the exponential autoregressive model,an inherent structure of the magnitude series are discussed,the different relations between magnitude and frequency in active period and quiet period are also explained in this paper.

The Threshold Effect of Factor Price Distortion on Technological Content of Exports:Evidence from China

Using panel data from 31 provinces in China,covering the period from 2003 to 2017,this article analyzes the threshold effect of factor price distortion on the technological content of exports.The results show that factor price distortion does not necessarily impede improvement in the quality of the technological content of exports.Instead,the adverse ejfect can be weakened when the value of per capita GDP is higher than RMB13,154 or the value of FDI goes beyond RMB480.9 billion.This is because a high regional economic development level alleviates the adverse effect of factor price distortion on the technological content of exports.Our results are robust when the dependent variable and sample years are changed.This article also addresses the endogeneity issue.We also consider the underlying mechanism through which factor price distortion affects the technological content of exports.

R&D,innovation and productivity relationships:Evidence from threshold panel model

This study investigates the nonlinear relationship between R&D expenditures,innovation,productivity,high-tech export products.Previous empirical research used linear standard structures to deal with these kinds of specifications,and it has shown that the linearity is frequently conditioned by other macroeconomic factors such as the level of development and the financial openness.Based on these arguments,our study investigates this question in econometric specification using panel smooth threshold regression methodology proposed by Gonzalez et al.in 2005.Our findings suggest that there is a threshold effect within the links between R&D expenditures,innovation,and productivity.The effect of R&D expenditures,innovation,productivity,and medium and high technology product exports is mixed.However,both positive and negative effects are found,depending on which innovation indicators are used or on which level of threshold variable is the most appropriate.The results advocate that the level of economic development can be considered as target indicators to conduct an innovation policy.

Digital economy and carbon dioxide emissions:Examining the role of threshold variables

Considering that previous literature has mainly focused on the impact of the digital economy(DE)on environmental degradation,ignoring the role of natural resources,this study uses two key factors(natural resource rent and anticorruption regulation)as threshold variables to reveal the effect of natural resources on the association between DE and carbon dioxide(CO_(2))emissions.In doing so,the study covers 97 countries,uses annual data between 2003 and 2019,and applies a panel threshold model.The outcomes present that the influence of the DE on CO_(2)emissions has a single-threshold effect(i.e.,there is an inverted U-shaped link between the DE and CO_(2)emissions)when natural resource rent is the threshold variable.Specifically,the DE significantly increases CO_(2)emissions when the natural resource rent is at a low-to-medium level,but the DE suppresses CO_(2)emissions growth when natural resource rent exceeds the threshold.Moreover,the DE drives overall CO_(2)emissions growth when anticorruption regulation is the threshold variable and there are double thresholds for its impact on CO_(2)emissions.Specifically,a rise in anticorruption regulation initially exacerbates the contribution of DE impact on CO_(2)emissions and then weakens it over time.Based on the results,the study proposes various implications,such as formulating a DE development strategy,considering natural resources in the development of the DE,and strengthening anti-corruption efforts in the field of environmental protection.

A study of the correlation between per capita income and the proportion of the service industry during China’s economic transition

Based on a provincial panel threshold regression model with per capita GDP as the threshold variable,this paper explores the correlation between per capita GDP and the proportion of employment in the service industry in different stages of China’s economic development.The results show that no matter the development stage,there is always a positive correlation between the two.The results also show that the more advanced the economic development stage,the bigger and more obvious is the regression coefficient.The empirical results based on stochastic frontier analysis(SFA)modeling indicate that the development of the service industry can always contribute to the improvement of national economic efficiency by creating employment opportunities and enhancing efficiencies in related industries.The more developed an economy is,the more significant is the effect.The results of descriptive statistics suggest that there is no empirical factual basis to support the belief that it is normal for China to have a low service industry proportion at its current economic development stage.This paper seeks to illustrate the negative influence of an underdeveloped service industry on China’s economy,and to encourage leapfrog development of the service industry in China.

Research on Modern Nonlinear Dynamic Model of Five-Elements Theory

This article studied on five elements system and set general and strict model expectations combining with Traditional Chinese Medicine Zang-fu organs theory,in which absolute stable state,conditional stable state or transient stability and instability in mathematical models were corresponding to human healthy state,sub-healthy state(pathological plateau phase) and health deterioration state respectively.Model parameters were set up according to the mutual generation and restriction relations among five elements.The dynamic model of Five-Elements System was built,of which impulse responses were corresponding to human response under TCM treatment.Analyses of initial value and excitation response were conducted by numerical simulation and results turned out to meet the requirements of general model expectation:five elements system dynamic model had self-organization function;there existed only one non-global stable point and instability region in the five-dimensional space consisting of variables,in which instability was corresponding to pathological deterioration;system stable region was an unbounded domain and it included the stable sub-regions of special straight line-type,ray-type and line segment-type.Among those ray-types,some contained "Regression Peak" were classed as conditional stable regions while others as absolute ones.The existence of this peak indicates that our body must exceed a "Regression Threshold" when transiting from sub-healthy state(pathological plateau phase) to healthy state through self-regulation mechanism.Impulse excitation can reduce certain threshold and then increase the system health level,which is complied with the operating principle of Five-Elements System and the empirical rule of TCM clinical practice.This model has revealed qualitatively the inherent movement law of Five-Elements System and thus provides a new analysis tool for basic theoretical study on TCM.