China's Sovereign Wealth Fund : Weakness and Challenges

The establishment of sovereign wealth funds in large developing countries has generated hot debate among participants in the international financial market. When accumulated foreign exchange reserves surpass a sufficient and an appropriate level, the costs, risks and impacts on the macro-economy of countries holding reserves need to be considered. The Chinese Government established China Investment Corporation (CIC) in 2007 to diversify its investment of foreign reserves and to raise investment income. However, because of certain conflicts of interest and institution-design caveats, CIC possesses some internal weakness, including a vague orientation, mixed investment strategies and inefficient bureaucratic style. Although the subprime crisis has softened certain regulations and lessened rejection by the USA of CIC potential investments, the increased volatility and uncertainty of the market means that CIC is facing some new challenges in terms of its investment decisions. Moreover, CIC is competing with other Chinese investment institutions for injections of funds from the Chinese Government.CIC, external challenge, internal weakness, foreign exchange reserve management

Fault Location in Power Distribution Systems via Deep Graph Convolutional Networks

This paper develops a novel graph convolutional network (GCN) framework for fault location in power distribution networks. The proposed approach integrates multiple measurements at different buses while taking system topology into account. The effectiveness of the GCN model is corroborated by the IEEE 123 bus benchmark system. Simulation results show that the GCN model significantly outperforms other widely-used machine learning schemes with very high fault location accuracy. In addition, the proposed approach is robust to measurement noise and data loss errors. Data visualization results of two competing neural networks are presented to explore the mechanism of GCN's superior performance. A data augmentation procedure is proposed to increase the robustness of the model under various levels of noise and data loss errors. Further experiments show that the model can adapt to topology changes of distribution networks and perform well with a limited number of measured buses.Comment: Accepcted by IEEE Journal on Selected Areas in Communicatio

The Realization and Dectection of Weyl Semimetals and Chiral Anomaly in Cold Atomic Systems

In this work, we describe a method to realize 3D Weyl semimetal by coupling multilayers of honeycomb optical lattice in the presence of a pair of Raman lasers. The Raman lasers render each isolated honeycomb layer a Chern insulator. With finite interlayer coupling, the bulk gap of the system closes at certain out-of-plane momenta due to Raman assisted tunnelling and result in the Weyl semimetal phase. Using experimentally relevant parameters, we show that both one and two pairs of Weyl points can be realized by tuning the interlayer coupling strength. We suggest that Landau-Zener tunnelling can be used to detect Weyl points and show that the transition probability increases dramatically when Weyl point emerges. The realization of chiral anomaly by using a magnetic field gradient is also discussed.Comment: 6 pages, 5 figures. Comments are welcom