Key Terms to Understand Reform and Opening Up

The China Academy of Translation has analyzed prevailing terms concerning the reform and opening-up policy and translated them into a number of foreign languages.The research institute is affiliated with the China International Publishing Group,the country’s leading international publisher.

Key Terms to Understand Reform and Opening Up

The China Academy of Translation has analyzed prevailing terms concerning the reform and opening-up policy and translated them into a number of foreign languages. The research institute is affiliated with the China International Publishing Group, the country’s leading international publisher. In each issue,Beijing Review presents a selection of these keywords to help readers more deeply understand this program.

Side-Channel Analysis for the Re-Keying Protocol of Bluetooth Low Energy

In the era of the Internet of Things,Bluetooth low energy(BLE/BTLE)plays an important role as a wellknown wireless communication technology.While the security and privacy of BLE have been analyzed and fixed several times,the threat of side-channel attacks to BLE devices is still not well understood.In this work,we highlight a side-channel threat to the re-keying protocol of BLE.This protocol uses a fixed long term key for generating session keys,and the leakage of the long term key could render the encryption of all the following(and previous)connections useless.Our attack exploits the side-channel leakage of the re-keying protocol when it is implemented on embedded devices.In particular,we present successful correlation electromagnetic analysis and deep learning based profiled analysis that recover long term keys of BLE devices.We evaluate our attack on an ARM Cortex-M4 processor(Nordic Semiconductor nRF52840)running Nimble,a popular open-source BLE stack.Our results demonstrate that the long term key can be recovered within only a small amount of electromagnetic traces.Further,we summarize the features and limitations of our attack,and suggest a range of countermeasures to prevent it.

Quantum dots-labeled polymeric scaffolds for in vivo tracking of degradation and tissue formation

The inevitable gap between in vitro and in vivo degradation rate of biomaterials has been a challenging factor in the optimal designing of scaffold’s degradation to be balanced with new tissue formation.To enable non-/minimum-invasive tracking of in vivo scaffold degradation,chemical modifications have been applied to label polymers with fluorescent dyes.However,the previous approaches may have limited expandability due to complicated synthesis processes.Here,we introduce a simple and efficient method to fluorescence labeling of polymeric scaffolds via blending with near-infrared(NIR)quantum dots(QDs),semiconductor nanocrystals with superior optical properties.QDs-labeled,3D-printed PCL scaffolds showed promising efficiency and reliability in quantitative measurement of degradation using a custom-built fiber-optic imaging modality.Furthermore,QDs-PCL scaffolds showed neither cytotoxicity nor secondary labeling of adjacent cells.QDs-PCL scaffolds also supported the engineering of fibrous,cartilaginous,and osteogenic tissues from mesenchymal stem/progenitor cells(MSCs).In addition,QDs-PCL enabled a distinction between newly forming tissue and the remaining mass of scaffolds through multi-channel imaging.Thus,our findings suggest a simple and efficient QDs-labeling of PCL scaffolds and minimally invasive imaging modality that shows significant potential to enable in vivo tracking of scaffold degradation as well as new tissue formation.

Recursive Least Squares Algorithm for a Nonlinear Additive System with Time Delay

This paper proposes a recursive least squares algorithm for a nonlinear additive system with time delay.By the Weierstrass approximation theorem and the key term separation principle, the model can be simplified as an identification model. Based on the identification model, a recursive least squares identification algorithm is used to estimate all the unknown parameters of the time-delayed additive system. An example is provided to show the effectiveness of the proposed algorithm.