Poverty and exclusion in urban China

This paper discusses how widespread poverty and exclusion are in urban China during the period of transition from central planning to a market economy. Two poverty lines have been employed to measure poverty rates in urban areas: a diagnostic poverty line calculated by the Asian Development Bank (ADB) experts and a benefit poverty line used in the Minimum Living Allowance Program of the Chinese government. Both sets of estimates show marked variations by province. According to the former standard, the poverty headcount of China in 1998 was estimated as 14.8 million, with a poverty rate of 4.7 percent. According to the later standard, the poverty headcount for 2007 is estimated as 22.7 million, amounting to a poverty rate of 3.9 percent. Poor people are generally not living in absolute poverty, as their basic needs in food, clothing and shelter can largely be met. However, they have low incomes and restricted consumption potential. Economic constraints also entail adverse consequences like poor health, poor education and limited social contacts. Two groups of people are here considered as the new poor: unemployed or laid-off workers and labor migrants. This means that China now has two new forms of urban poverty which are caused by different factors and are combined with different forms of deprivation. Therefore, policy programs designed to eradicate poverty in urban areas have to be tailored carefully to the poor people's special needs. Job creation and a comprehensive social protection system are here proposed as two effective instruments in the fight against urban poverty. --

Topological Soliton with Nonzero Hopf Invariant in Yang-Mills-Higgs Model

We propose a topological soliton or instanton solution with nonzero Hopf invariant to the 3+1D non-Abelian gauge theory coupled with scalar fields. This solution, which we call Hopf soliton, represents a spacetime event that makes a $2\pi$ rotation of the monopole. Although the action of this Hopf soliton is logarithmically divergent, it may still give relevant contributions in a finite-sized system. Since the Chern-Simons term for the unbroken $U(1)$ gauge field may appear in the low energy effective theory, the Hopf soliton may possibly generate fractional statistics for the monopoles.Comment: 16 pages, 1 figure

A Survey on Bayesian Deep Learning

A comprehensive artificial intelligence system needs to not only perceive the environment with different `senses' (e.g., seeing and hearing) but also infer the world's conditional (or even causal) relations and corresponding uncertainty. The past decade has seen major advances in many perception tasks such as visual object recognition and speech recognition using deep learning models. For higher-level inference, however, probabilistic graphical models with their Bayesian nature are still more powerful and flexible. In recent years, Bayesian deep learning has emerged as a unified probabilistic framework to tightly integrate deep learning and Bayesian models. In this general framework, the perception of text or images using deep learning can boost the performance of higher-level inference and in turn, the feedback from the inference process is able to enhance the perception of text or images. This survey provides a comprehensive introduction to Bayesian deep learning and reviews its recent applications on recommender systems, topic models, control, etc. Besides, we also discuss the relationship and differences between Bayesian deep learning and other related topics such as Bayesian treatment of neural networks.Comment: To appear in ACM Computing Surveys (CSUR) 202