Design and Evaluation of a Differential Accelerometer for Drop-Tower Equivalence Principle Test with Rotating Masses

A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth＇s gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle （NEP）. We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.

Hybrid Meta-Model Based Design Space Differentiation Method for Expensive Problems

In this work,a hybrid meta-model based design space differentiation（HMDSD）method is proposed for practical problems.In the proposed method,an iteratively reduced promising region is constructed using the expensive points,with two different search strategies respectively applied inside and outside the promising region.Besides,the hybrid meta-model strategy applied in the search process makes it possible to solve the complex practical problems.Tested upon a serial of benchmark math functions,the HMDSD method shows great efficiency and search accuracy.On top of that,a practical lightweight design demonstrates its superior performance.

Design of all-optical temporal differentiator using a Moir fiber grating

We design and demonstrate an all-optical temporal differentiator based on a simple Moire fiber grating operated in reflection. The simulation results prove that a single Moire fiber grating with only one π-phase shifted point can act as the first-order temporal differentiator and that a Moire fiber grating incorporating two symmetrical π-phase shifted points can act as the second-order temporal differentiator. A practical Moire fiber grating is fabricated, thereby proving that such a grating can act as the first-order temporal differentiator. Our results verify the feasibility, flexibility, and accuracy of the proposed method.

An AES chip with DPA resistance using hardware-based random order execution

This paper presents an AES（advanced encryption standard） chip that combats differential power analysis （DPA） side-channel attack through hardware-based random order execution.Both decryption and encryption procedures of an AES are implemented on the chip.A fine-grained dataflow architecture is proposed,which dynamically exploits intrinsic byte-level independence in the algorithm.A novel circuit called an HMF（Hold-MatchFetch） unit is proposed for random control,which randomly sets execution orders for concurrent operations.The AES chip was manufactured in SMIC 0.18μm technology.The average energy for encrypting one group of plain texts（128 bits secrete keys） is 19 nJ.The core area is 0.43 mm^2.A sophisticated experimental setup was built to test the DPA resistance.Measurement-based experimental results show that one byte of a secret key cannot be disclosed from our chip under random mode after 64000 power traces were used in the DPA attack.Compared with the corresponding fixed order execution,the hardware based random order execution is improved by at least 21 times the DPA resistance.