Local Cyber-physical Attack with Leveraging Detection in Smart Grid

A well-designed attack in the power system can cause an initial failure and then results in large-scale cascade failure. Several works have discussed power system attack through false data injection, line-maintaining attack, and line-removing attack. However, the existing methods need to continuously attack the system for a long time, and, unfortunately, the performance cannot be guaranteed if the system states vary. To overcome this issue, we consider a new type of attack strategy called combinational attack which masks a line-outage at one position but misleads the control center on line outage at another position. Therefore, the topology information in the control center is interfered by our attack. We also offer a procedure of selecting the vulnerable lines of its kind. The proposed method can effectively and continuously deceive the control center in identifying the actual position of line-outage. The system under attack will be exposed to increasing risks as the attack continuously. Simulation results validate the efficiency of the proposed attack strategy.Comment: Accepted by IEEE SmartGridComm 201

Interaction-induced first order correlation between spatially-separated 1D dipolar fermions

We calculate the ground-state properties of fermionic dipolar atoms or molecules in a one-dimensional double-tube potential by using the Luttinger liquid theory and the density matrix renormalization-group calculation. When the external field is applied near a magic angle with respect to the double-tube plane, the long-ranged dipolar interaction can generate a spontaneous correlation between fermions in different tubes, even when the bare intertube tunneling rate is negligibly small. Such interaction-induced correlation strongly enhances the contrast of the interference fringes and therefore can be easily observed in the standard time-of-flight experiment.Comment: Same as the published versio

Characteristics of the global copper raw materials and scrap trade systems and the policy impacts of China's import ban

Copper raw materials (CRM) and copper waste and scrap (CWS) are the two main sources of copper manufactured products. Due to the uneven geographical distribution of copper production and consumption, international CRM and CWS trade developed. However, no study has explored the complicated interdependencies between CRM trade and CWS trade or investigated the characteristics of this multiplex trade system. This study uses trade records from 1988 to 2017 to construct multiplex trade networks: a global CRM trade network and a global CWS trade network. The evolution of copper trade from 1988 to 2017 is reviewed, and the intricate relationships in the multiplex trade network are identified. It is found that CWS trade has a highly positive correlation with CRM trade, but there are obvious differences between CWS trade and CRM trade in the multilateral trade structure. Multilateral trade structures driven by core exporting countries and core importing countries are prominent in CRM trade and CWS trade, respectively. In addition, the impacts of China's restrictive policies on the multiplex trade system are analyzed. The results provide policy implications for countries regarding copper resource security strategies and safeguarding the multiplex trading system.</p