Optimal classification in sparse Gaussian graphic model

Consider a two-class classification problem where the number of features is much larger than the sample size. The features are masked by Gaussian noise with mean zero and covariance matrix $\Sigma$, where the precision matrix $\Omega=\Sigma^{-1}$ is unknown but is presumably sparse. The useful features, also unknown, are sparse and each contributes weakly (i.e., rare and weak) to the classification decision. By obtaining a reasonably good estimate of $\Omega$, we formulate the setting as a linear regression model. We propose a two-stage classification method where we first select features by the method of Innovated Thresholding (IT), and then use the retained features and Fisher's LDA for classification. In this approach, a crucial problem is how to set the threshold of IT. We approach this problem by adapting the recent innovation of Higher Criticism Thresholding (HCT). We find that when useful features are rare and weak, the limiting behavior of HCT is essentially just as good as the limiting behavior of ideal threshold, the threshold one would choose if the underlying distribution of the signals is known (if only). Somewhat surprisingly, when $\Omega$ is sufficiently sparse, its off-diagonal coordinates usually do not have a major influence over the classification decision. Compared to recent work in the case where $\Omega$ is the identity matrix [Proc. Natl. Acad. Sci. USA 105 (2008) 14790-14795; Philos. Trans. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci. 367 (2009) 4449-4470], the current setting is much more general, which needs a new approach and much more sophisticated analysis. One key component of the analysis is the intimate relationship between HCT and Fisher's separation. Another key component is the tight large-deviation bounds for empirical processes for data with unconventional correlation structures, where graph theory on vertex coloring plays an important role.Comment: Published in at http://dx.doi.org/10.1214/13-AOS1163 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Commentary on English Translation of “Wen Fu”

Since the middle of the 20th century, “Wen Fu” has been translated into the Western world by many Chinese and foreign translators, which vastly promoted the spread and acceptance of ancient Chinese literary theory in the West and was of great significance to facilitate the exchange and cooperation between Chinese and foreign academic circles on the study of “Wen Fu”. By the comparison of Sam Hamill’s and Stephen Owen’s English versions of “Wen Fu”, this paper is designed to explore the translators’ translation purpose, analyze the differences in translation strategies, and expound the discrepancies in word selection so as to extend the existing studies of “Wen Fu”

Research on Language Characteristics of Business Letter Writing

Business English letter writing is an important language skill especially for students majoring in English and business English. A large number of scholars both at home and abroad have already started researching on business letter writing, and the fields involved are quite extensive. However, the analysis of the language features of business English letter writing still has yet to fully tapped, which has a great value and space to explore. Especially in China which is increasingly open to the outside world with a booming economy, such a study will significantly promote the multilateral economic intercourse.This study would systematically summarize the relevant language features of business letter writing, supplemented by a number of examples of demonstration, to deepen the reader’s understanding of business letter writing. In addition, the results of this study will provide some inspirations and suggestions for the instruction of business letter writing

A Translation Study of “Saxon’s Heroes After the Calamity” From the Perspective of Brazilian Cannibalism

Brazilian scholars have proposed cannibalism to get rid of the cultural and spiritual colonization of strong cultural nations, which becomes an important branch of the post-colonial theory. In 1963, De Campos linked cannibalism with the translation theory in On Translation as Creation and Criticism. This thesis will study “Saxon’s Heroes after the Calamity” based on the translation theory of Brazilian cannibalism to provide the research of Lin Shu’s translations with a new perspective

The SPSS-based Analysis of Reading Comprehension—Take Grade Eight English Mid-term Test for Example

Based on some language testing theories, an analysis of an English Mid-term Examination of grade eight students of JingZhi Middle School is made in this paper. By means of SPSS statistical software, the former study firstly makes a whole analysis of the test paper, which covers descriptive statistics, reliability and validity. Subsequently, on the basis of the former study, this study mainly makes an analysis of the relationship of all the items in reading comprehension from the perspective of facility value, discrimination index, reliability and validity. The research aims to find some problems in reading comprehension in this test paper. Thus, according to the results of this analysis, the quality of test papers can be improved and some advice can be given to language teaching

Functional assessment of hydrophilic domains of lea proteins from distant organisms

Late embryogenesis abundant (LEA) proteins play a protective role during desiccation and oxidation stresses. LEA3 proteins are a major group characterized by a hydrophilic domain (HD) with a highly conserved repeating 11-amino acid motif. We compared four different HD orthologs from distant organisms: (i) DrHD from the extremophilic bacterium Deinococcus radiodurans; (ii) CeHD from the nematode Caenorhabditis elegans; (iii) YlHD from the yeast Yarrowia lipolytica; and (iv) BnHD from the plant Brassica napus. Circular dichroism spectroscopy showed that all four HDs were intrinsically disordered in phosphate buffer and then folded into a-helical structures with the addition of glycerol or trifluoroethanol. Heterologous HD expression conferred enhanced desiccation and oxidation tolerance to Escherichia coli. These four HDs protected the enzymatic activities of lactate dehydrogenase (LDH) by preventing its aggregation under desiccation stress. The HDs also interacted with LDH, which was intensified by the addition of hydrogen peroxide (H2O2), suggesting a protective role in a chaperone-like manner. Based on these results, the HDs of LEA3 proteins show promise as protectants for desiccation and oxidation stresses, especially DrHD, which is a potential ideal stress-response element that can be applied in synthetic biology due to its extraordinary protection and stress resistance ability. Please click Additional Files below to see the full abstract

Dietary Supplementation of Astaxanthin Improved the Growth Performance, Antioxidant Ability and Immune Response of Juvenile Largemouth Bass (Micropterus salmoides) Fed High-Fat Diet

High-fat diet (HFD) usually induces oxidative stress and astaxanthin is regarded as an excellent anti-oxidant. An 8-week feeding trial was conducted to investigate the effects of dietary astaxanthin supplementation on growth performance, lipid metabolism, antioxidant ability, and immune response of juvenile largemouth bass (Micropterus salmoides) fed HFD. Four diets were formulated: the control diet (10.87% lipid, C), high-fat diet (18.08% lipid, HF), and HF diet supplemented with 75 and 150 mg kg−1 astaxanthin (HFA1 and HFA2, respectively). Dietary supplementation of astaxanthin improved the growth of fish fed HFD, also decreased hepatosomatic index and intraperitoneal fat ratio of fish fed HFD, while having no effect on body fat. Malondialdehyde content and superoxide dismutase activity were increased in fish fed HFD, astaxanthin supplementation in HFD decreased the oxidative stress of fish. The supplementation of astaxanthin in HFD also reduced the mRNA levels of Caspase 3, Caspase 9, BAD, and IL15. These results suggested that dietary astaxanthin supplementation in HFD improved the growth performance, antioxidant ability and immune response of largemouth bass.publishedVersio

A Fast and Scalable Authentication Scheme in IoT for Smart Living

Numerous resource-limited smart objects (SOs) such as sensors and actuators have been widely deployed in smart environments, opening new attack surfaces to intruders. The severe security flaw discourages the adoption of the Internet of things in smart living. In this paper, we leverage fog computing and microservice to push certificate authority (CA) functions to the proximity of data sources. Through which, we can minimize attack surfaces and authentication latency, and result in a fast and scalable scheme in authenticating a large volume of resource-limited devices. Then, we design lightweight protocols to implement the scheme, where both a high level of security and low computation workloads on SO (no bilinear pairing requirement on the client-side) is accomplished. Evaluations demonstrate the efficiency and effectiveness of our scheme in handling authentication and registration for a large number of nodes, meanwhile protecting them against various threats to smart living. Finally, we showcase the success of computing intelligence movement towards data sources in handling complicated services.Comment: 15 pages, 7 figures, 3 tables, to appear in FGC

Sparse data-extended fusion method for sea surface temperature prediction on the East China Sea.

The accurate temperature background field plays a vital role in the numerical prediction of sea surface temperature (SST). At present, the SST background field is mainly derived from multi-source data fusion, including satellite SST data and in situ data from marine stations, buoys, and voluntary observing ships. The characteristics of satellite SST data are wide coverage but low accuracy, whereas the in situ data have high accuracy but sparse distribution. For obtaining a more accurate temperature background field and realizing the fusion of measured data with satellite data as much as possible, we propose a sparse data-extended fusion method to predict SST in this paper. By using this method, the actual observed sites and buoys data in the East China Sea area are fused with Advanced Very High Resolution Radiometer (AVHRR) Pathfinder Version 5.0 SST data. Furthermore, the temperature field in the study area were predicted by using Long Short-Term Memory (LSTM) and Gate Recurrent Unit (GRU) deep learning methods, respectively. Finally, we obtained the results by traditional prediction methods to verify them. The experimental results show that the method we proposed in this paper can obtain more accurate prediction results, and effectively compensate for the uncertainty caused by the parameterization of ocean dynamic process, the discrete method, and the error of initial conditions

Fine-grained Private Knowledge Distillation

Knowledge distillation has emerged as a scalable and effective way for privacy-preserving machine learning. One remaining drawback is that it consumes privacy in a model-level (i.e., client-level) manner, every distillation query incurs privacy loss of one client's all records. In order to attain fine-grained privacy accountant and improve utility, this work proposes a model-free reverse $k$-NN labeling method towards record-level private knowledge distillation, where each record is employed for labeling at most $k$ queries. Theoretically, we provide bounds of labeling error rate under the centralized/local/shuffle model of differential privacy (w.r.t. the number of records per query, privacy budgets). Experimentally, we demonstrate that it achieves new state-of-the-art accuracy with one order of magnitude lower of privacy loss. Specifically, on the CIFAR-$10$ dataset, it reaches $82.1\%$ test accuracy with centralized privacy budget $1.0$; on the MNIST/SVHN dataset, it reaches $99.1\%$/$95.6\%$ accuracy respectively with budget $0.1$. It is the first time deep learning with differential privacy achieve comparable accuracy with reasonable data privacy protection (i.e., $\exp(\epsilon)\leq 1.5$). Our code is available at https://github.com/liyuntong9/rknn