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Predicting Credit Bond Default with Deep Learning: Evidence from China

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Journal of Social Computing 2024年第1期5卷 36-45页

作者： Ning Zhang Wenhe Li Haoxiang Chen Binshu Jia Pei Deng school of Information Central University of Finance and EconomicsBeijing 100081China SDIC Taikang Trust Co. Ltd.Beijing 100034China

China’s credit bond market has rapidly expanded in recent ***,since 2014,the number of credit bond defaults has been increasing rapidly,posing enormous potential risks to the stability of the financial *** study proposed a deep learning approach to predict credit bond defaults in the Chinese market.A convolutional neural network(CNN)was selected as the classification model and to reduce the extreme imbalance between defaulted and non-defaulted bonds,and a generative adversarial network(GAN)was used as the oversampling *** on 31 financial and 20 non-financial indicators,we collected Wind data on all credit bonds issued and matured or defaulted from 2014 to *** experimental results showed that our GAN+CNN approach had superior predictive performance with an area under the curve(AUC)of 0.9157 and precision of 0.8871 compared to previous research and other commonly used classification models-including the logistic regression,support vector machine,and fully connected neural network models-and oversampling techniques-including the synthetic minority oversampling technique(SMOTE)and Borderline SMOTE *** one-year predictions,indicators of solvency,capital structure,and fundamental properties of bonds are proved to be the most important indicators.

关键词： credit bond default prediction convolutional neural network imbalanced data processing generative adversarial network

Bolstering integrity in environmental data science and machine learning requires understanding socioecological inequity

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 171-179页

作者： Joe F.Bozeman III school of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA30332USA school of Public Policy Georgia Institute of TechnologyAtlantaGA30332USA

Socioecological inequity in environmental data science—such as inequities deriving from data-driven approaches and machine learning(ML)—are current issues subject to debate and *** is growing consensus around embedding equity throughout all research and design domains—from inception to administration,while also addressing procedural,distributive,and recognitional ***,practically doing so may seem onerous or daunting to *** current perspective helps to alleviate these types of concerns by providing substantiation for the connection between environmental data science and socioecological inequity,using the Systemic Equity Framework,and provides the foundation for a paradigmatic shift toward normalizing the use of equity-centered approaches in environmental data science and ML *** the integrity of environmental data science and ML is just beginning from an equity-centered tool development and rigorous application *** this end,this perspective also provides relevant future directions and challenges by overviewing some meaningful tools and strategies—such as applying the Wells-Du Bois Protocol,employing fairness metrics,and systematically addressing irreproducibility;emerging needs and proposals—such as addressing data-proxy bias and supporting convergence research;and establishes a ten-step path ***,the work that environmental scientists and engineers do ultimately affect the well-being of us all.

关键词： Equity Bias Machine Learning Data Science Justice Systemic Equity

Perturbations of Dirac operators,spectral Einstein functionals and the Noncommutative residue

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Acta Mathematica Sinica,English Series 2024年

作者： Sining WEI Yong Wang school of Data Science and Artificial Intelligence Dongbei University of Finance and Economics school of Mathematics and Statistics Northeast Normal University

In this paper, we introduce the spectral Einstein functional for perturbations of Dirac operators on manifolds with boundary. Furthermore, we provide the proof of the Dabrowski-SitarzZalecki type theorems associated with the spectral Einstein functionals for perturbations of Dirac operators, particularly in the cases of on 4-dimensional manifolds with boundary.

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Asymptotic Inferences in the Random Coefficient Autoregressive Model with Time-functional Variance Noises

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Acta Mathematicae Applicatae Sinica 2024年

作者： En-wen ZHU Zi-wei DENG Han-jun ZHANG Jun CAO Xiao-hui LIU Department of Mathematics and Statistics Changsha University of Science and Technology school of Statistics and Data Science and Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and Economics school of Mathematics and Computational Science Xiangtan University

This paper considers the random coefficient autoregressive model with time-functional variance noises, hereafter the RCA-TFV model. We first establish the consistency and asymptotic normality of the conditional least squares estimator for the constant coefficient. The semiparametric least squares estimator for the variance of the random coefficient and the nonparametric estimator for the variance function are constructed,and their asymptotic results are reported. A simulation study is presented along with an analysis of real data to assess the performance of our method in finite samples.

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MATHEMATICAL MODELING AND BIFURCATION ANALYSIS FOR A BIOLOGICAL MECHANISM OF CANCER DRUG RESISTANCE

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Acta Mathematica Scientia 2024年第3期44卷 1165-1188页

作者：包康博梁桂珍田天海张兴安 school of Information Engineering and Artificial Intelligence Lanzhou University of Finance and EconomicsLanzhou730020China school of Mathematics and Statistics Central China Normal UniversityWuhan430079China school of Mathematics and Information Science Xinxiang UniversityXinxiang453003China school of Mathematical Sciences Monash UniversityMelbourneVIC3800Australia

Drug resistance is one of the most intractable issues in targeted therapy for cancer *** has also been demonstrated to be related to cancer heterogeneity,which promotes the emergence of treatment-refractory cancer cell *** on how cancer cells develop resistance during the encounter with targeted drugs and the immune system,we propose a mathematical model for studying the dynamics of drug resistance in a conjoint heterogeneous tumor-immune *** analyze the local geometric properties of the equilibria of the *** simulations show that the selectively targeted removal of sensitive cancer cells may cause the initially heterogeneous population to become a more resistant ***,the decline of immune recruitment is a stronger determinant of cancer escape from immune surveillance or targeted therapy than the decay in immune predation *** analysis of model parameters provides insight into the roles of the immune system combined with targeted therapy in determining treatment outcomes.

关键词： mathematical model drug resistance cancer heterogeneity immune system targeted therapy

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The impact of the COVID-19 prevention and economic interventions on express delivery industry:Evidence from China

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Journal of Management Science and Engineering 2024年第1期9卷 16-37页

作者： Juan Liu Jiafu Tang Minghe Sun school of Economics Dongbei University of Finance&Economics(DUFE)Dalian116025China school of Management Science&Engineering Dongbei University of Finance&Economics(DUFE)Dalian116025China Department of Management Science and Statistics College of BusinessThe University of Texas at San AntonioSan AntonioUSA

As a fundamental logistics service,the express delivery(ED)industry provides production and consumption activities to maintain efficient supply chain *** plays an important role in promoting industrial development and maintaining daily life and *** study examined the effects of COVID-19 on the ED industry using ED package delivery data from 31 provinces(autonomous regions and municipalities)in *** a difference-in-differences method,the COVID-19 outbreak was found to have a positive effect and epidemic prevention and control(EPC)policies were found to have negative effects on the development of the ED *** addition to EPC policies,the Chinese government has implemented other short-term economic interventions(SEI),such as the resumption of work and production(RWP),policies to balance economic growth,and epidemic *** study divided the pandemic period into three stages to analyze the different impacts of EPC and SEI policy changes on the ED *** RWP policies adopted during the pandemic positively impacted the volume and income of packages delivered to the ED *** conclusions of this study are significant for the ED industry in addressing public health emergencies and for the Chinese government to formulate EPC and SEI policies during epidemic periods.

关键词： COVID-19 Epidemic prevention and control policy Resumption of work and production Express delivery industry Quasi-experiment Difference-in-differences

Study on Path Selection and Implementation Effect of Counselors in College Students’Career Planning Education

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Journal of Contemporary Educational Research 2024年第5期8卷 59-64页

作者： Fang Guo Shujun Luo Weihan Li school of finance and Economics Shenzhen Institute of Information TechnologyShenzhen 518000Guangdong ProvinceChina

Under the background of a severe job market and fierce talent competition,the career planning education of college students is of great *** this study,a combination of quantitative and qualitative research methods was used;500 students in Shenzhen Polytechnic of Information Technology were surveyed by questionnaire,and 40 counselors were interviewed in depth to comprehensively analyze the role and practical effect of counselors in career planning *** research showed that the role positioning of counselors includes the guide of students’career development,emotional support,and job-hunting strategy,and the specific path selection involves the strengthening of professional knowledge,the construction of interpersonal relationship networks,and personalized *** on the survey and interview data,this paper constructed a model for enhancing the role of counselors in career planning education and put forward a set of targeted work paths.

关键词： College counselors Career planning Role positioning Path selection Implementation effect

Influence of ambient temperature on the CO_(2)emitted of light-duty vehicle

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Journal of Environmental Sciences 2024年第6期140卷 59-68页

作者： Dan Tan Yachao Wang Jianwei Tan Jiachen Li Changyu Wang Yunshan Ge school of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China

Because of global warming,people have paid more attention to greenhouse gas emitted by *** quantify the impact of temperature on vehicle CO_(2)emissions,this study was conducted using the world light vehicle test cycle on two light-duty E10 gasoline vehicles a ambient temperatures of-10,0,23,and 40℃,and found that CO_(2)emission factors of Vehicle1 in the low-speed phase were 22.07%and 20.22%higher than those of Vehicle 2 at cold star and hot start under-10℃.The reason was vehicle 1 had a larger displacement and more friction pairs than vehicle *** was the highest CO_(2)emission at the low-speed phase due to low average speed,frequent acceleration,and *** CO_(2)temperature factor and the ambient temperature had a strong linear correlation(R2=0.99).According to CO_(2)temperature factors and their relationships,CO_(2)emission factors of other ambien temperatures could be calculated when the CO_(2)emission factor of 23℃was obtained,and the method also could be used to obtain the CO_(2)temperature factors of different *** separate the effect of load setting and temperature variation on CO_(2)emission quantitatively a method was *** results showed that the load setting was dominant for the CO_(2)emission *** with 23℃,the CO_(2)emission for vehicle 1 caused by load setting variation were 62.83 and 47.42 g/km,respectively at-10 and 0℃,while those fo vehicle 2 were 45.01 and 35.63 g/km,respectively.

关键词： CO_(2)emission Ambient temperature E10 gasoline Light-duty vehicle WLTC

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Effect of the vortical structures on the hydrodynamic performance of a pitching hydrofoil

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Journal of Hydrodynamics 2024年第2期36卷 406-420页

作者： Rui Yuan Hui-yun Hao Qin Wu Yun-qing Liu Biao Huang school of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

The objective is to study the vortical structural behaviors of a transient pitching hydrofoil and their effects on the hydrodynamic performance. The pitching motion of the hydrofoil is set to pitch up with an almost constant rate from 5° to 15° and then back to 5°, with the Reynolds number 4.4×10^(5) and the frequency 2 Hz. The results show that the main coherent structures around the pitching hydrofoil include small-scale laminar separation bubble (LSB), large-scale second vortex (SV) and trailing edge vortex (TEV) which are all vortical. The relationship between the vortical structure and the lift is investigated with the finite-domain impulse theory. It indicates that the major part of the lift is contributed by the LSB, whereas the shedding and the formation of the SV and TEV cause the fluctuation of the lift. The proper orthogonal decomposition (POD) method is applied to capture the most energetic modes, revealing that the LSB mode occupies a large amount of energy in the flow field. The dynamic mode decomposition (DMD) method accurately extracts the dominant frequency and modal characteristics, with the first mode corresponding to the mean flow, the second mode corresponding to the LSB structure and the third and fourth modes corresponding to the vortex shedding.

关键词： Hydrodynamics vortical structures finite-domain impulse theory proper orthogonal decomposition(POD) dynamic mode decomposition(DMD) Pitching hydrofoil