科研成果

2020
Huang H, Gao Y, Zhang H, Li B. Weighted Lasso Estimates for Sparse Logistic Regressions: Non-asymptotic Properties with Measurement Error. Acta Mathematica Scientia. 2020.Abstract
When we are interested in high-dimensional system and focus on classification performance, the $\ell_{1}$-penalized logistic regression is becoming important and popular. However, the Lasso estimates could be problematic when penalties of different coefficients are all the same and not related to the data. We proposed two types of weighted Lasso estimates depending on covariates by the McDiarmid inequality. Given sample size $n$ and dimension of covariates $p$, the finite sample behavior of our proposed methods with a diverging number of predictors is illustrated by non-asymptotic oracle inequalities such as $\ell_{1}$-estimation error and squared prediction error of the unknown parameters. We compare the performance of our methods with former weighted estimates on simulated data, then apply these methods to do real data analysis.
Conesa JC, Li Q. Welfare Implications of Switching to Consumption Taxation. Journal of Economic Dynamics and Control [Internet]. 2020. 访问链接Abstract
We evaluate a reform of the US tax system switching to consumption taxation instead of income taxation. We do so in an environment that allows for progressivity of consumption taxes through differential tax rates between basic and non-basic consumption goods. The consumption tax system that maximizes aggregate welfare involves a 4% subsidy on basic consumption goods and a 68% tax on non-basic goods. Such a tax scheme generates 10% higher output in the long run, with a small increase in inequality. Nonetheless, the bench- mark with progressive income taxes and mild consumption taxes provides higher welfare on aggregate in the steady state, and even more so if we consider the transition.
Zhao X, Hu H, Zhou Y, Bai Y. What Are the Long-term Effects of Child Loss on Parental Health? Social Integration as Mediator. Comprehensive Psychiatry [Internet]. 2020;100(152182):1-8. 访问链接Abstract
Background Some bereaved parents experience a decreasing trajectory of grief, while others fail to adapt over the long term and persistently suffer from negative health consequences. This study investigates the mediating role of social integration in the relationship between losing an only child and parental health in a family-oriented society. Method A sample of 1828 bereaved parents and 4739 non-bereaved parents was drawn from a 10-city survey in China. Regression methods were used to examine the impact of child loss on parental health, and Sobel test was applied to examine the mediating role of social integration. Results Bereaved parents who lost their only child have worse self-rated health and more negative affect than the non-bereaved parents, which lasted for years after the death of the only child. The Sobel test shows that 24.8% of the total effects on self-rated health and 6.7% of the total effects on negative affect can be explained via decreased social integration. The gender of parents and child as well as fertility intentions are important sources of heterogeneity in the Chinese culture. Limitation The results based on cross-sectional data may only reveal correlation rather than causality. The data was retrieved from self-reported questionnaires and there is a lack of objective measures of parental health. Moreover, the detailed mechanisms behind how child loss resulted in less social integration should be further explored. Conclusions Significant disparities in health outcomes and social integration were found for bereaved parents relative to the non-bereaved parents. Future work is needed to assess the health of bereaved parents, identify the vulnerable and disadvantaged groups, and design inclusive intervention programs.
ZHANG Y, LIN S, WANG R, WANG Y, Wang Y, QIAN W, HUANG R. When Sorting Network Meets Parallel Bitstreams: A Fault-Tolerant Parallel Ternary Neural Network (TNN) Accelerator based on Stochastic Computing, in 23rd Design, Automation and Test in Europe Conference (DATE). Grenoble, France; 2020:1287-1290.
Zhang L, Wang J, Zhang G, Huang Q. Whether climatic factors influence the frequency of punctual on-demand deliveries of groundwater for irrigation? Empirical study in the North China Plain. Climatic Change. 2020;159:269–287.
Gong Q, Liu C, Peng Q, Wang L. Will CEOs with banking experience lower default risks? Evidence from P2P lending platforms in China. Finance Research Letters. 2020;(10).
Wang J, Ma J, Wang Y, Wang N, Wang L, Zhang D, Wang F, Lv Q. Will online digital footprints reveal your relationship status? an empirical study of social applications for sexual-minority men. Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies. 2020;4:1–23.
Zuo A, Wang J, Huang Q. Willingness to accept compensation for land fallowing: results from a survey of village representatives in Northern China. Australian Journal of Agricultural and Resource Economics. 2020;64:845–866.
Wang HC, Chen XR, Lu KD, Tan ZF, Ma XF, Wu ZJ, Li X, Liu YH, Shang DJ, Wu YS, et al. Wintertime N2O5 uptake coefficients over the North China Plain. Science Bulletin. 2020;65:765-774.Abstract
The heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) plays an important role in regulating NOx. The N2O5 uptake coefficient, c(N2O5), was determined using an iterative box model that was constrained to observational data obtained in suburban Beijing from February to March 2016. The box model determined 2289 individual c(N2O5) values that varied from <0.001 to 0.02 with an average value of 0.0046 +/- 0.0039 (and a median value of 0.0032). We found the derived winter c(N2O5) values in Beijing were relatively low as compared to values reported in previous field studies conducted during winter in Hong Kong (average value of 0.014) and the eastern U.S. coast (median value of 0.0143). In our study, field evidence of the suppression of c(N2O5) values due to pNO3 content, organics and the enhancement by aerosol liquid water content (ALWC) is in line with previous laboratory study results. Low ALWC, high pNO3 content, and particle morphology (inorganic core with an organic shell) accounted for the low c (N2O5) values in the North China Plain (NCP) during wintertime. The field-derived c(N2O5) values are well reproduced by a revised parameterization method, which includes the aerosol size distribution, ALWC, nitrate and organic coating, suggesting the feasibility of comprehensive parameterization in the NCP during wintertime. (C) 2020 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.
Sandanov DV, Liu Y, Wang Z, Korolyuk YA. Woody and Herbaceous Plants of Inner Asia: Species Richness and Ecogeorgraphic Patterns. Contemporary Problems of Ecology. 2020;13:360-369.Abstract
The diversity of vascular plants in Inner Asia has been researched; the main environmental factors determining the distribution of species belonging to various life forms and having different distribution range sizes have been identified. The key factors determining species diversity in Inner Asia are past climate changes and precipitation parameters. By contrast, the temperature conditions of the current climate do not affect the species richness significantly. The following current climatic parameters are important for woody plants: precipitation seasonality, mean precipitation in winter and spring, and diurnal range of temperature. Quite the opposite, the species richness of herbaceous plants is determined by climate-change velocity from the mid-Holocene and Last Glacial Maximum, the spatial heterogeneity of precipitation, and mean summer temperatures. Over time, distribution ranges of rare plants in the studied region may be reduced due to the increasing aridization.
Xun Pang and Chong Chen, “The Hirschman Effect of China’s Bilateral Cross-Currency SWAP Agreements”. World Economy and Politics (in Chinese). 2020.Abstract
Bilateral cross-currency SWAP agreements (BSAs) were rejuvenated during the GFC by the Federal Reserve of the United States to provide liquidity to selected governments in dire financial straits. After the crisis, BSAs rapidly and widely spread around the globe and become a major component of the global financial safety net. Interestingly, it is not the United States but China which occupies the center of the global BSA network. China has signed BSAs with a diverse pool of states since 2009, and has far more partners than any other countries. While existing studies mainly focus on the motivations driving China and its partner states to enter BSAs, this paper is intended to evaluate foreign policy consequences of China’s BSAs. Asymmetric interdependence and asymmetric information, as two key features of the economic relationship between China and its partner states in BSAs, are expected to make other countries be more supportive to China’s position in global affairs, leading to a convergence of their foreign policy preferences. This is the classic “Hirschman effect”. To empirically identify the “Hirschman effect”, we use measures of states’ foreign policy ideal points based on votes in the United States General Assembly. We apply a quantitative analysis to estimate the average effect and conduct a case study to trace and explain the development of the effect over time. In the large-N study, we draw data on 191 countries between 2009 and 2018 and specify a multilevel model with varying intercepts to control for unobserved heterogeneity in the dimension of time and space. Empirical evidence suggests that BSAs significantly drive the foreign policy preferences of China and other states to converge. Then we focus on Argentina as an in-depth case study. Different from conventional case studies, we conduct a “quantitative case study” and apply the Synthetic Control Method to estimate and quantify the causal effect of signing a BSA with China in 2009 on the distance between foreign policy ideal points of Argentina and China. The case study confirms the presence of the “Hirschman effect” suggested by theory and found in the regression analysis. It further reveals several suggestive but interesting points, including 1) activating SWAP lines may strengthen the effect, whereas the effect may be weakened by the provision of emergency liquidity assistance from the US or the IMF; 2) BSAs with China may impact on left-wing governments more strongly than right-wing governments; and 3) the Chinese government may strengthen the effect by changing the size of the committed SWAP line.
曲天书, 吴玺宏, 王奕文.; 2020. 一种基于声传递函数学习的非监督声源定向方法. China patent CN ZL202010485452.9.
曲天书, 吴玺宏, 高山.; 2020. 一种基于移动麦克风阵列的房间边界估计方法. China patent CN ZL202010010360.5.
曲天书, 吴玺宏, 彭超.; 2020. 一种基于说话人嵌入空间的竞争说话人数量估计方法及系统. China patent CN ZL202010009945.5.
曲天书, 吴玺宏, 陈建非.; 2020. 一种室内早期反射声定位方法及系统. China patent CN ZL202010010386.X.
曲天书, 吴玺宏, 林晶.; 2020. 一种抗高频空间混叠的3D音频系统及实现方法. China patent CN ZL202010009944.0.
谢小荣, 满九方, 陈垒.; 2020. 一种柔性直流宽频带振荡的广谱自适应阻塞控制方法. China patent CN ZL 202010994876.8.
曲天书, 吴玺宏, 彭超.; 2020. 一种说话人数未知的多通道语音分离方法. China patent CN ZL202010796279.4.
雷瑭洵. 上古汉语“告”的音义、句法及其演变. In: 语言学论丛. Vol. 61. 北京: 商务印书馆; 2020.Abstract
“告”属于言告类双及物动词,主要有去声(长入)、入声(短入)两读,既往的研究多认为读音差别是上下等级性的反映。本文认为,去声读法表示“训告、告诫”之义,入声读法表示“言告、礼告”之义。在《左传》时期,入声读法的“言告”和“礼告”义的句法表现有别:前者的间接宾语(IO,言说对象)不需用“于/於”引出,进入“告+IO+DO”(双宾式);后者的间接宾语IO需要用“于”引出,进入“告+DO+于/於IO”(“于/於”字式)。“礼告”义与甲骨文中祭祀动词“告”的用法一脉相承,在战国时期随着社会变化逐渐消失,与言告合流。去声读法的“训告,告诫”义,其间接宾语IO不需用“于/於”引出,但在早期文献中,直接宾语(DO,言说内容)可以用“于”引出。“告”的去入两读的音义对立在唐代口语中可能已经变得模糊,合并读为去声。“告”的读音去入之别不是上下方向的改变,因此也不可能是由表使动的-s尾引起。
刘霄, 邱文琪, 杨钋. 专业硕士资助政策能否缓解扩招引发的教育不公平——基于首都22所高校的三次研究生调查. 教育发展研究. 2020;40(21):47-55.Abstract
本文利用"北京大学首都高等教育质量与学生发展调查项目"在2010年、2012年和2014年针对22所首都高校15417位硕士研究生的调查数据,通过双重差分的方法,研究了专业硕士扩招和资助政策改革对教育公平的影响。结果发现,随着政策的实施,虽然专业硕士尤其是精英院校专业硕士的生源质量提高了,但专业硕士扩张的同时也带来了一定程度的教育不公平问题。与MMI假设和EMI假设一致,专业硕士的扩招优先满足了高学历家庭学生的入学机会。然而,与资助理论相悖,虽然资助政策在不断变革,但专业硕士项目并未显著招收到更多来自低收入家庭的学生。 

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