Cox’s proportional hazards model is the most commonly used model for regression analysis of failure time data and some methods have been developed for its variable selection under different ...situations. In this paper, we consider a general type of failure time data, case K interval-censored data, that include all of other types discussed as special cases, and propose a unified penalized variable selection procedure. In addition to its generality, another significant feature of the proposed approach is that unlike all of the existing variable selection methods for failure time data, the proposed approach allows dependent censoring, which can occur quite often and could lead to biased or misleading conclusions if not taken into account. For the implementation, a coordinate descent algorithm is developed and the oracle property of the proposed method is established. The numerical studies indicate that the proposed approach works well for practical situations and it is applied to a set of real data arising from Alzheimer’s Disease Neuroimaging Initiative study that motivated this study.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
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•Different cracking modes of pre-oxidised and vacuum-annealed Cr coatings were studied.•Crack resistance of Cr coating was greatly enhanced due to recrystallization effect.•The ...brittle diffusion layer was easier to generate micro-cracks under external loadings.•Oxygen transportation, inter-diffusion and phase transformation led to pre-failure of Cr coatings.
Chromium (Cr)-coated zirconium alloys have been considered as a promising candidate material for accident-tolerant fuel (ATF) cladding for nuclear reactors because of their superior oxidation resistance under accident conditions. However, the oxidation and diffusion behaviours that occur in the Cr coating–Zr substrate system at high temperatures significantly affect the microstructure and mechanical properties of the coating, leading to cracking modes that are distinct from those of the as-deposited coating. To understand the effects of oxidation and inter-diffusion on the fracture mechanisms of Cr-coated Zry-4 alloys, in situ three-point bending tests were conducted in this study. Crack initiation and propagation in the oxidised and vacuum-annealed coatings were observed in real time. The results showed that high-temperature exposure led to recrystallisation of the Cr coating (columnar grains transformed into equiaxed grains), which greatly enhanced the crack resistance of the Cr coating. However, a diffusion-induced intermetallic ZrCr2 layer and an α-Zr(O) layer (which transformed from β-Zr owing to oxygen transportation) formed simultaneously at the coating/substrate interface. The micro-cracks formed in these brittle layers rapidly penetrated all the layers under external load, leading to premature failure of the coated sample.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Green technology innovation is an effective way through which to achieve carbon neutrality and sustainable development. Based on provincial panel data of 30 provinces in China from 2005 to 2018, this ...work examines the tripartite relationship among green technology innovation, resource misallocation, and carbon emission performance by constructing panel regression models and a dynamic threshold panel model. The research results show that green technology innovation significantly improves carbon emission performance. Further analysis shows that both capital and labour misallocation have a negative impact on carbon emission performance and hinder the contribution of green technology innovation to the improvement of carbon emission performance. The regression results show that there is a threshold effect of green technology innovation on carbon emission performance: as the degree of resource misallocation increases, the positive impact of green technology innovation on carbon emission performance gradually decreases. This study provides an important reference for policy-makers in implementing policies to improve carbon emission performance. Policy-makers should continue to promote the level of green technology innovation and improve the efficiency of labour and capital allocation.
With the deteriorating ecological environment, green technological innovation (GTI) has become an effective way to strengthen environmental protection and promote economic development. Based on the ...2011–2019 panel data of 30 provinces in China, this study constructs a spatial Durbin model to examine the spatial spillover effect of environmental regulation and digital finance on green technological innovation. Meanwhile, a moderating effect model and threshold effect model are employed to explore the function of digital finance in terms of the impact of environmental regulation on green technological innovation. The empirical results show that: 1) environmental regulation has significantly promoted local GTI, green invention patents (GIP) and green utility model patents (GUP), while having had negative spatial spillover effects on those three things in neighboring regions. Digital finance promotes GTI and GIP in both local and neighboring areas, but digital finance’s direct and spatial spillover effects on GUP are not significant. 2) A regional analysis shows that different intensities of environmental regulation and different digital finance levels in different regions lead to the heterogeneity of green technological innovation’s response to them. 3) Digital finance produces a positive moderating effect on environmental regulation affecting GTI and GIP in local and neighboring regions. However, digital finance’s moderating effect in terms of the influence of environmental regulation on GUP is not significant. 4) When digital finance reaches a certain threshold, environmental regulation will have a stronger role in promoting GTI. Therefore, to improve regional green technology innovation and environmental governance, the government should strengthen the integration of digital technology and financial services, and promote the construction of environmental supervision systems and green innovation policy systems.
Improving green energy efficiency (GEE) and promoting green economic transformation are important goals for China to achieve sustainable economic development in the post-COVID-19 era. Based on panel ...data of 27 manufacturing industries in China, this paper uses GMM model and threshold model to study the impact of environmental regulation and technological innovation on green energy efficiency. Our findings show that technological innovation promotes green energy efficiency in both pollution-intensive and clean industries, and its promotion effect is more pronounced in pollution-intensive industries. Environmental regulation not only directly improves the green energy efficiency of polluting industries and clean industries, but also plays a positive intermediary role between technology and green energy efficiency. The impact of technological innovation on GEE has a threshold effect of environmental regulation. When environmental regulation did not cross the threshold, technological innovation does not significantly promote GEE. The promotion effect of technological innovation on GEE will increase with the strengthening of environmental supervision. Therefore, the government should formulate reasonable environmental regulations according to the industry heterogeneity to vigorously promote the green energy efficiency of the manufacturing industry.
We consider a regression analysis of multivariate interval-censored failure time data where the censoring may be informative. To address this, an approximated maximum likelihood estimation approach ...is proposed under a general class of semiparametric transformation models, and in the method, the frailty approach is employed to characterize the informative interval censoring. For the implementation of the proposed method, we develop a novel EM algorithm and show that the resulting estimators of the regression parameters are consistent and asymptotically normal. To evaluate the empirical performance of the proposed estimation procedure, we conduct a simulation study, and the results indicate that it performs well for the situations considered. In addition, we apply the proposed approach to a set of real data arising from an AIDS study.
Considering China's green credit policy (GCP) as a quasi-natural experiment, this study discusses the effect of GCP on enterprise green innovation (GI) using a difference-in-difference method based ...on data from Chinese listed companies from 2009 to 2020. The results indicate that green credit enhances the strategic GI of heavy polluters while significantly inhibiting essential GI, thus suggesting the nonexistence of the Porter effect. In addition, the inhibition effect is attributed to an increase in financing constraints and a reduction in government subsidies, firm research and development investment, and employment scale. This disincentive effect is particularly pronounced in privately owned firms, small cities, and capital-intensive low-profitability firms. Resource misallocation caused by the GCP fails to stimulate the green transformation of heavily polluting industries through the Porter effect. Hence, governments should establish a diversified green financial system, integrate green venture capital and GI elements, and guide the flow of social capital toward green industries.
As an emerging financial tool, green bonds can broaden the financing channels of enterprises and stimulate the green innovation of enterprises. Based on the A-share data of Chinese listed companies ...from 2012 to 2020, this paper analyzes the impact of green bonds on green technology innovation by using a method of Difference in Difference with Propensity Score Matching (PSM-DID). We found that green bonds can significantly improve enterprise green technology innovation. Its positive impact is attributed to increases in media attention and R&D capital investment and a reduction in financing constraints. Green bonds play a greater role in the green innovation of strong financial constraints enterprises, non-SOEs and large-scale enterprises. Our findings have important reference significance for the improvement of the resource allocation role of green bonds and achievement of sustainable growth.
With the development of the Internet economy, online shopping has become the main way for consumers to obtain goods, especially for organic infant milk. Do millennials who grew up in the era of ...Internet prefer online purchasing channel? Or are they stickier to online channel than offline channel? To solve these issues, we conduct the regression analysis of a latent class and the model of Quadratic Engel Almost Ideal Demand System aimed at the user stickiness in China. Moreover, we further analyze the environmental social governance effect of multi-channel stickiness, which is able to further explore the impact of environmental social governance investment strategy on consumers’ purchasing behavior. Through these analyses, we confirm the online channel stickiness and platform stickiness of Taobao. Results also indicate that (i) The primary factor influencing the inertia of consumption and trade volume is the channel and platform stickiness, the latter positively affects the former. (ii) The ESG rating index plays a positively moderating role in the consumers’ user stickiness. (iii) Environment and Social Score have a significant positive impact on online platform stickiness.
As a way for the government to integrate funds and make up for fiscal deficits, bond issuance plays an important role in environmental governance and thus impacts environmental quality. Based on the ...panel data of 30 provinces in China from 2011 to 2019, this study utilizes spatial econometric and threshold panel models to investigate the influence of local government debt on environmental pollution. The empirical results are as follows: 1) Both environmental pollution and local government debt have a significant positive spatial agglomeration effect. 2) The relationship between local government debt and environmental pollution presents a nonlinear U-shaped curve. Specifically, when the debt scale is less than the threshold value, local government debt plays a role in restraining environmental pollution, and when the debt scale exceeds the threshold value, the influence of local government debt on environmental pollution plays a promoting role. 3) A regional heterogeneity test suggests that in the eastern region, the influence of local government debt on environmental pollution is always restraining, while in the central and western regions, this influence is consistent with the national level, showing a U-shaped feature. This study provides a reference for policy-makers in improving environmental quality from the perspective of local government debt. Policy-makers should keep the scale of government debt within a moderate range to avoid the deterioration of environmental quality caused by excessive debt.
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