Traditionally, the contact between the end-effector and the target is modeled as a parallel spring-damp model, which requires a time-consumed tuning of values of stiffness and damping factor and an extra force sensor fixed on the end-effector. The above drawbacks inspire the application of complementary problem to uniformly describe the unilateral contact for space robot. A dynamical equation of the space robot with unilateral contact is derived, and a numerical method is developed utilizing the Lemke algorithm. By numerical calculation of a planar 3 degree-of-freedom (DOF) manipulator fastened on a 3 DOF floating base, the effectiveness of the dynamical model is verified.

A non-invasive, high-efficient and low-cost fault attack is realized on FPGA-based cryptographic applications. Based on the setup failures in critical paths, faults are injected into the FPGA devices by lowering the supply voltage. Then the encryption key can be retrieved efficiently with an appropriate fault model. In the attack experiments, the full 128-bit key of AES is retrieved correctly with only 8 pairs of correct and faulty ciphertexts within a few minutes, by using a power supply and a personal computer, based on the FPGA platform.

Radio frequency identification (RFID) suffers extremely limited chip area and energy resource. A novel elliptic curve cryptographic (ECC) processer based on generalized binary Hessian curve (GBHC) is designed and implemented. The authors employ Montgomery Ladder scalar-multiplication algorithm and optimized w-coordinate method for accelerating the computing timing, and well-design circular shift register (CSR) architecture and clock gating technology for reducing the consumption of area and energy. The results show that the proposed processer has fast computing speed, minimal chip area and ultra-low energy consumption, and is capable to resist some types of side channel attack (SCA) such as simple power analysis (SPA).

The authors discuss the performance and area of different large-scale Booth multipliers with high radices used in Montgomery algorithm using secondary encoded scheme. The modular multiplication is implemented with SMIC 0.13μm technology at the frequency of 160 MHz and 125 MHz respectively based on the 128-bit multiplier and 256-bit multiplier with Booth 64, 128 and 256 encoding. Experiment result shows that the multiplier with Booth 64, 128 and 256 can achieve the same timing performance, while the area rises as radix rises due to the complexity in pre-computation and partial product generation.

A snowstorm event caused by explosive cyclone happened in Liaoning Province in March 3-5, 2007. The cyclone caused heavy snow, strong winds and low visibility, which had large influences onthetraffic, particularly on aviation. The authors analyze the process fromthe large-scale circulation, mobile path and intensity of the cyclone, moisture conditions, cold and warm air, etc. The results show that strong baroclinic wave is the main reason for the development of the explosive cyclone, and that high potential vorticity in the stratosphere promote the development, too. High-and low-level jets, divergence field, vertical movement constitute a strong secondary circulation. The snowstorm in Shenyang is closely related to the movement of cyclones path, water vapor transport and the degree of vertical movement.