Research on performance enhancement for electromagnetic analysis and power analysis in cryptographic LSI

制度:新 ; 報告番号:甲3785号 ; 学位の種類:博士(工学) ; 授与年月日:2012/11/19 ; 早大学位記番号:新6161Waseda Universit

A Corpus-based Study of Shields in Conversations of Chinese EFL Learners

As an important part of the fuzzy language, hedges have become a common linguistic phenomenon and frequently applied in daily spoken language. In this study, the authors investigated the shields-using frequency of Chinese EFL learners from the Multi-modal Spoken English Corpus of Chinese Learners-Science & Engineering Majors (MSECCL-SEM). In this study, the classification of Prince et al. (1982) will be adopted. Six shields that are frequently used in spoken English have been searched, namely, “I think”, “in my opinion”, “maybe”, “according to”, “as we (all) know”, “it is said that”. Data are analyzed by the application of Wordsmith 6.0 and SPSS 25.0. Through this study, we attempt to explore the characteristics of shields in spoken English of EFL learners, especially the differences in terms of gender, various language proficiency and two different kinds of shields. Through this research, the authors hope to guide second language teaching and learning by finding out the use of shields in EFL students' daily spoken language and analyzing its potential causes

The Impact of the COVID-19 on Online Food Delivery Service: Evidence from China

The COVID-19 has had a profound effect on society as a whole. To examine the effect of the COVID-19 on online food delivery services, we collected sales data from a large online food delivery platform in 195 Chinese cities from November 2019 to July 2020. Interrupted time series analysis and time-varying difference-in-difference methods were used to estimate the impact of the COVID-19 and city lockdown policies on online food delivery services. The COVID-19 had a considerable negative effect on the online food delivery services. Lockdown policies caused further disruptions. As the pandemic and lockdown policies ended, the negative impacts dissipated. This finding reflected digital channels’ resilience to the catering industry during the pandemic and helped it withstand its impact. There were significant differences among urban characteristics. The government can formulate relevant policies to deal with potential public health risks in the future based on these findings

Correlation Power Analysis with Companding Methods

AbstractCompanding methods have been profoundly applied in signal processing for quantization. And various companding schemes have been proposed to improve the PAPR (Peak to Average Power Ratio) of OFDM systems. In this paper, based on the exploration of the features of μ-law functions, we propose Correlation Power Analysis (CPA) with μ-law companding methods. μ-law expanding function is used to preprocess the power traces collected during AES encryption on ASIC and FPGA respectively. Experiments show that it reduces the number of power traces to recover all the key bytes as much as 25.8% than the conventional CPA