3,199 research outputs found
Distributed Robust Learning
We propose a framework for distributed robust statistical learning on {\em
big contaminated data}. The Distributed Robust Learning (DRL) framework can
reduce the computational time of traditional robust learning methods by several
orders of magnitude. We analyze the robustness property of DRL, showing that
DRL not only preserves the robustness of the base robust learning method, but
also tolerates contaminations on a constant fraction of results from computing
nodes (node failures). More precisely, even in presence of the most adversarial
outlier distribution over computing nodes, DRL still achieves a breakdown point
of at least , where is the break down point of
corresponding centralized algorithm. This is in stark contrast with naive
division-and-averaging implementation, which may reduce the breakdown point by
a factor of when computing nodes are used. We then specialize the
DRL framework for two concrete cases: distributed robust principal component
analysis and distributed robust regression. We demonstrate the efficiency and
the robustness advantages of DRL through comprehensive simulations and
predicting image tags on a large-scale image set.Comment: 18 pages, 2 figure
Continuous Authentication for Voice Assistants
Voice has become an increasingly popular User Interaction (UI) channel,
mainly contributing to the ongoing trend of wearables, smart vehicles, and home
automation systems. Voice assistants such as Siri, Google Now and Cortana, have
become our everyday fixtures, especially in scenarios where touch interfaces
are inconvenient or even dangerous to use, such as driving or exercising.
Nevertheless, the open nature of the voice channel makes voice assistants
difficult to secure and exposed to various attacks as demonstrated by security
researchers. In this paper, we present VAuth, the first system that provides
continuous and usable authentication for voice assistants. We design VAuth to
fit in various widely-adopted wearable devices, such as eyeglasses,
earphones/buds and necklaces, where it collects the body-surface vibrations of
the user and matches it with the speech signal received by the voice
assistant's microphone. VAuth guarantees that the voice assistant executes only
the commands that originate from the voice of the owner. We have evaluated
VAuth with 18 users and 30 voice commands and find it to achieve an almost
perfect matching accuracy with less than 0.1% false positive rate, regardless
of VAuth's position on the body and the user's language, accent or mobility.
VAuth successfully thwarts different practical attacks, such as replayed
attacks, mangled voice attacks, or impersonation attacks. It also has low
energy and latency overheads and is compatible with most existing voice
assistants
Phase diagram of Kondo-Heisenberg model on honeycomb lattice with geometrical frustration
We calculated the phase diagram of the Kondo-Heisenberg model on
two-dimensional honeycomb lattice with both nearest-neighbor and
next-nearest-neighbor antiferromagnetic spin exchanges, to investigate the
interplay between RKKY and Kondo interactions at presence of magnetic
frustration. Within a mean-field decoupling technology in slave-fermion
representation, we derived the zero-temperature phase diagram as a function of
Kondo coupling and frustration strength . The geometrical frustration
can destroy the magnetic order, driving the original antiferromagnetic (AF)
phase to non-magnetic valence bond state (VBS). In addition, we found two
distinct VBS. As is increased, a phase transition from AF to Kondo
paramagnetic (KP) phase occurs, without the intermediate phase coexisting AF
order with Kondo screening found in square lattice systems. In the KP phase,
the enhancement of frustration weakens the Kondo screening effect, resulting in
a phase transition from KP to VBS. We also found a process to recover the AF
order from VBS by increasing in a wide range of frustration strength. Our
work may provide deeper understanding for the phase transitions in
heavy-fermion materials, particularly for those exhibiting triangular
frustration
Monotonicity Results for Arithmetic Means of Concave and Convex Functions
By majorization approaches, some known results on monotonicity
of the arithmetic means of convex and concave functions are proved and
generalized once again
A Correlational Study of Language Learning Motivation and Strategies of Chinese Undergraduate
Since the 1960s the focus of research in second language acquisition has shifted from teaching to learning, and language learners become the center of language teaching and learning. As to learners, language learning motivation and language learning strategies are two main research topics. The present study investigates Chinese college students’ motivation types and strategy use as well as the relationships between language learning motivation and language learning strategies. The study aims to show whether motivation is related to learning strategies, and to shed light on the study of learning motivation, learning strategies, and pedagogy. Key Words: language learning motivation; language learning strategies; gender; correlatio
A Preliminary Study on Stylistic Features of The Rainbow
Every writer has their individual qualities and writing styles. The Rainbow, one masterpiece of D.H. Lawrence, can really reflect his writing styles. In this paper, the analysis will be made respectively in terms of four categories: lexical categories, grammatical categories, figures of speech, and cohesion and context. A conclusion can be drawn that Lawrence's style is simplicity and directness and he dislikes complicating the superficial account, and turns to the natural and the essential tools to reveal the most original and animalized nature of the human being which, in his mind, is the most important and the essence of the nature rules. Key Words: stylistic features; lexical categories; grammatical categories; figures of speech; cohesion; contex
- …