One More Weight is Enough: Toward the Optimal Traffic Engineering with OSPF

Traffic Engineering (TE) leverages information of network traffic to generate a routing scheme optimizing the traffic distribution so as to advance network performance. However, optimize the link weights for OSPF to the offered traffic is an known NP-hard problem. In this paper, motivated by the fairness concept of congestion control, we firstly propose a new generic objective function, where various interests of providers can be extracted with different parameter settings. And then, we model the optimal TE as the utility maximization of multi-commodity flows with the generic objective function and theoretically show that any given set of optimal routes corresponding to a particular objective function can be converted to shortest paths with respect to a set of positive link weights. This can be directly configured on OSPF-based protocols. On these bases, we employ the Network Entropy Maximization(NEM) framework and develop a new OSPF-based routing protocol, SPEF, to realize a flexible way to split traffic over shortest paths in a distributed fashion. Actually, comparing to OSPF, SPEF only needs one more weight for each link and provably achieves optimal TE. Numerical experiments have been done to compare SPEF with the current version of OSPF, showing the effectiveness of SPEF in terms of link utilization and network load distribution

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