摘要：
A two-step hydrothermal process was used to successfully create Ti3+, N, and B co-doped TiO2 modified with nitrogen doped graphene quantum dots (Ti3+/N/B-TiO2@NGQDs (TNBTN)) composite photocatalyst for photodegradation of bisphenol A (BPA) and methyl orange (MO) under visible-light illumination. The prepared TNBTN composite demonstrated significantly enhanced visible light catalytic performance. Especially, the apparent rate constant of BPA degradation with TNBTN was approximately 56.9 times that of pure TiO2, which was attributed to broader visible light absorbance and faster transmission and separation of photoinduced charge. In addition, the mechanism of BPA and MO degradation with TNBTN was distinct.
关键词：
long memory;regime switching;FIEGARCH;MRS-FIEGARCH
摘要：
Recent research suggests that long memory can be caused by regime switching and is easily confused with it. However, if the causes of confusion were properly controlled, they could be distinguished. Motivated by this idea, our study aims to distinguish between the long memory and regime switching of financial volatility. We firstly modeled the long memory and regime switching of volatility using the Fractionally Integrated Exponential GARCH (FIEGARCH) and Markov Regime-Switching EGARCH (MRS-EGARCH) frameworks, respectively, and performed a simulation study on their finite-sample properties when innovations followed a non-normal distribution. Subsequently, we demonstrated the confusion between the FIEGARCH and MRS-EGARCH processes using simulations. A recent study theoretically proved that the time-varying smoothing probability series can induce the presence of significant long memory in the regime-switching process. To control for its effect, the two-stage two-state FIEGARCH and MRS-FIEGARCH frameworks are proposed. The Monte Carlo studies showed that both frameworks can effectively distinguish between the pure FIEGARCH and pure MRS-EGARCH processes. When the MRS-FIEGARCH model was further employed to fit series generated with the MRS-FIEGARCH process, it outperformed the ordinary FIEGARCH model. Finally, an empirical study of NASDAQ index return was conducted to demonstrate that our MRS-FIEGARCH model can provide potentially more reliable long-memory estimates, identify the volatility states and outperform both the FIEGARCH and MRS-EGARCH models.
作者机构：
[Chen, Zhongwen] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421002, Peoples R China.;[Shi, Yanlin] Macquarie Univ, Dept Actuarial Studies & Business Analyt, Sydney, NSW 2109, Australia.;[Shu, Ao] Hunan Univ, Business Sch, Changsha 410012, Peoples R China.
通讯机构：
[Ao Shu] B;Business School, Hunan University, Changsha 410012, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
mortality rates;Lee–Carter model;time-varying coefficients;rotated age pattern;life expectancy
摘要：
Influential existing research has suggested that rather than being static, mortality declines decelerate at young ages and accelerate at old ages. Without accounting for this feature, the forecast mortality rates of the popular Lee-Carter (LC) model are less reliable in the long run. To provide more accurate mortality forecasting, we introduce a time-varying coefficients extension of the LC model by adopting the effective kernel methods. With two frequently used kernel functions, Epanechnikov (LC-E) and Gaussian (LC-G), we demonstrate that the proposed extension is easy to implement, incorporates the rotating patterns of mortality decline and is straightforwardly extensible to multi-population cases. Using a large sample of 15 countries over 1950-2019, we show that LC-E and LC-G, as well as their multi-population counterparts, can consistently improve the forecasting accuracy of the competing LC and Li-Lee models in both single- and multi-population scenarios.
期刊：
IEEE Transactions on Engineering Management,2023年:1-19 ISSN：0018-9391
通讯作者：
Wang, ZR
作者机构：
[Liu, Xin] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421007, Peoples R China.;[Wang, Zongrun; Zhou, Yanju] Cent South Univ, Sch Business, Changsha 410017, Peoples R China.;[Kumar, Ajay] EMLYON Business Sch, F-69130 Ecully, France.;[Biswas, Baidyanath] Trinity Coll Dublin, Trinity Business Sch, Dublin D02 F6N2, Ireland.
通讯机构：
[Wang, ZR ] C;Cent South Univ, Sch Business, Changsha 410017, Peoples R China.
关键词：
Analytical models;Big data analytics;Cognition;Costs;Data mining;data science in healthcare;Diseases;healthcare technology;Medical diagnostic imaging;Medical services;online medicine;PQDR-LDA model;text mining
摘要：
Disease information mining is one of the critical factors affecting users' perception of the disease and has attracted extensive attention from the information management community in recent years. If the mined disease information is incompatible with the disease information perceived by the user, it will eventually lead to the loss of users from the online medical consultation platform, degrading its operation and management. Using existing models to mine disease information leads to significant errors when users perceive the disease. Therefore, this research extends the latent Dirichlet allocation (LDA) and Twitter-LDA models to propose an intelligent topic model, PQDR-LDA. Compared with the Twitter-LDA model, the proposed model has a smaller perplexity value, stronger generalization ability, greater coherence value, lower correlation between topics, and stronger ability in extracting the disease information. It is found that the accuracy of disease diagnosis is very low, and the user's need for perceiving the disease will be reduced while using the traditional model to mine only the text of user questions on an online medical consultation platform. The accuracy of disease diagnosis does not decrease while only mining the doctor's reply text. Disease information that is more suitable for the consultation text can be obtained, which in fact cannot meet the user's real appeal for health, and reduces the users’ needs in perceiving the disease. These findings have important management implications for the platform's operation and decision-making. Besides, users will ask questions in more medical texts simultaneously, which makes things more complicated. Unique management insights are obtained based on the disease information mining of user consultation texts through multiple consultation texts and multiple doctor replies. IEEE
通讯机构：
[Li, C ] W;Wuhan Univ Sci & Technol, Evergrande Sch Management, Wuhan 430081, Hubei, Peoples R China.;Hengyang Normal Univ, Coll Econ & Management, Hengyang 421010, Hunan, Peoples R China.
关键词：
dual channel supply chain;evolutionary game;Quality and safety traceability of agricultural products;spillover effect
摘要：
Quality and Safety Traceability (QST) is an effective means of ensuring the quality and safety of agricultural products and requires the simultaneous, continuous and rapid involvement of all stakeholders in the agricultural supply chain. Therefore, we first constructed a tripartite evolutionary game model consisting of producers, supermarkets and e-commerce platforms. Second, we analysed the dynamic evolutionary process of the three players and the conditions for stable strategy choice. Finally, Matlab R2021a is used for simulation to analyse the choice of stabilisation strategies for different decision makers under changes in key parameters. The research results show that: (1) if the benefits of participating in QST exceed the spillover effects of other stakeholders in the supply chain participating in QST, all stakeholders in the dual channel agricultural supply chain will eventually voluntarily participate in QST. (2) With the same initial intention, supermarkets/e-commerce platforms reach equilibrium and stability earlier than producers. The stronger the initial willingness of stakeholders to participate, the shorter the time it takes to reach equilibrium and stability. (3) The higher the traceability cost-benefit conversion rate of producers/supermarkets/e-commerce platforms, the faster they can participate in QST. However, the higher the traceability cost-benefit conversion rate of supermarkets/e-commerce platforms, the faster the supermarkets/e-commerce platforms can participate in QST and the slower the producers can participate in QST. (4) The lower the spillover benefits received by stakeholders, the faster they participate in QST. However, at the same level of spillovers, the more stakeholders participate in QST, the slower the speed at which producers, supermarkets and e-commerce platforms participate in QST. Based on evolutionary game analysis and simulation results, we propose suggestions for producers, supermarkets and e-commerce platforms to participate in QST simultaneously, continuously and rapidly in stages.
摘要：
Urban clusters are important carriers for cities to participate in international competition and cooperation, and a booster for urban sustainable development. This study measured the degree of urban clusters by utilizing the panel data of 278 cities in China during 2004-2016. Then, an extended meta-frontier data envelopment analysis (EM-DEA) model was applied to estimate the total-factor ecological performance (UTEP) and decompose it into two sub-index from the perspective of "resource conservation" and "environmental friendliness". On these bases, we employed a dynamic panel data approach to examine and demonstrate the relationship between urban cluster and UTEP in two dimensions, and further explored transmission channels of urban clusters on UTEP by adding the mediating effect. The results show that resource conservation increases first and then decreases with the increasing of urban clustering level, while environmental friendliness showed the opposite trend, making the latter become the main way for urban clusters to improve the UTEP. Industrial structure supererogation and rationalization are transmission channels for environmental friendliness rather than resource conservation in the way of improvement of UTEP. Technology innovation, as well as technology diffusion, also improves UTEP to some extent. In addition, urban clusters in eastern and central China have the greatest improvement in UTEP, while such effects are not the case in western China. Urban clusters in the second half sample period are more conducive to the improvement of the UTEP, with these potentially being the gains from the improvement of the level and quality of urban clusters.
期刊：
Journal of Advanced Transportation,2020年2020 ISSN：0197-6729
通讯作者：
Fu, Zhuo
作者机构：
[Tang, Qiong; Fu, Zhuo; Zhang, Dezhi] Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;[Tang, Qiong] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421002, Peoples R China.;[Tang, Qiong; Fu, Zhuo; Zhang, Dezhi] Smart Transport Key Lab Hunan Prov, Changsha 410075, Peoples R China.;[Qiu, Meng] Chinese Univ Hong Kong, Inst Data & Decis Analyt, Shenzhen 518172, Peoples R China.;[Li, Minyi] RMIT Univ, Sch Sci, Melbourne, Vic 3000, Australia.
通讯机构：
[Fu, Zhuo] C;[Fu, Zhuo] S;Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;Smart Transport Key Lab Hunan Prov, Changsha 410075, Peoples R China.
摘要：
In this paper, a single-vehicle static partial repositioning problem (SPRP) is investigated, which distinguishes the user dissatisfaction generated by different stations. The overall objective of the SPRP is to minimize the weighted sum of the total operational time and the total absolute deviation from the target number of bikes at all stations. An iterated local search is developed to solve this problem. A novel loading and unloading quantity adjustment operator is proposed to further improve the quality of the solution. Experiments are conducted on a set of instances from 30 to 300 stations to demonstrate the effectiveness of the proposed customized solution algorithm as well as the adjustment operator. Using a small example, this paper also reveals that the unit penalty cost has an effect on the repositioning strategies.
作者机构：
[Tang, Qiong; Fu, Zhuo; Zhang, Dezhi] Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;[Tang, Qiong] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421002, Peoples R China.;[Tang, Qiong; Fu, Zhuo; Zhang, Dezhi] Smart Transport Key Lab Hunan Prov, Changsha 410075, Peoples R China.;[Guo, Hao] Jinan Univ, Sch Management, Guangzhou 510632, Peoples R China.;[Li, Minyi] RMIT Univ, Sch Sci, Melbourne, Vic 3000, Australia.
通讯机构：
[Fu, Zhuo] C;[Fu, Zhuo] S;Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;Smart Transport Key Lab Hunan Prov, Changsha 410075, Peoples R China.
摘要：
In this paper, a bike repositioning problem with stochastic demand is studied. The problem is formulated as a two-stage stochastic programming model to optimize the routing and loading/unloading decisions of the repositioning truck at each station and depot under stochastic demands. The goal of the model is to minimize the expected total sum of the transportation costs, the expected penalty costs at all stations, and the holding cost of the depot. A simulated annealing algorithm is developed to solve the model. Numerical experiments are conducted on a set of instances from 20 to 90 stations to demonstrate the effectiveness of the solution algorithm and the accuracy of the proposed two-stage stochastic model.
摘要：
A kind of coenzyme A (CoA)-silver coordination complex (CoA-Ag) was in-situ developed and verified to accelerate the electron transferring and electrochemical catalysis of H2O2 decomposition to enhance the cathode ECL intensity of CdTe@CdS QDs. Afterward, a convenient label-free signal-on ECL approach was constructed for CoA detection with excellent specificity. In addition, the unique ECL enhancing phenomenon was also proposed to assay the enzymatic activity of histone acetyltransferases (HAT) and screen relevant inhibitors, exhibiting a promising potential in the practical application of biochemical research, disease diagnosis and drug discovery.
摘要：
This article constructs an environmental logistics performance index (ELPI) for assessing the overall performance in green transportation and logistics practices of 112 countries. The index is measured by logistics performance index (LPI), CO2 emissions and oil consumption from the transport sector, using a range-adjusted measure (RAM) of the data envelopment analysis (DEA). ELPI effectively reflects the tradeoff between logistics efficiency and environmental protection in transportation. This article analyzes the impact of income and region on ELPI scores and discusses those countries’ reduction potential in oil consumption intensity and carbon intensity. The main finding of the research work is that ELPI is strongly correlated with LPI, and countries with high performance in LPI generally perform well in ELPI. Similar to the characteristics of LPI, ELPI is also closely related to income and region. During our study period, high income countries performed best, while Sub-Saharan Africa countries performed worst. However, some exceptions such as Venezuela, RB and Benin, indicate that the level of development of logistics performance and green transportation can outperform or lag behind their income or region group peers.
