124 research outputs found
Non-Malleable Codes for Small-Depth Circuits
We construct efficient, unconditional non-malleable codes that are secure
against tampering functions computed by small-depth circuits. For
constant-depth circuits of polynomial size (i.e. tampering
functions), our codes have codeword length for a -bit
message. This is an exponential improvement of the previous best construction
due to Chattopadhyay and Li (STOC 2017), which had codeword length
. Our construction remains efficient for circuit depths as
large as (indeed, our codeword length remains
, and extending our result beyond this would require
separating from .
We obtain our codes via a new efficient non-malleable reduction from
small-depth tampering to split-state tampering. A novel aspect of our work is
the incorporation of techniques from unconditional derandomization into the
framework of non-malleable reductions. In particular, a key ingredient in our
analysis is a recent pseudorandom switching lemma of Trevisan and Xue (CCC
2013), a derandomization of the influential switching lemma from circuit
complexity; the randomness-efficiency of this switching lemma translates into
the rate-efficiency of our codes via our non-malleable reduction.Comment: 26 pages, 4 figure
The Space Experiment of the Exo-ecosystem
The experiment of exo-ecosystem and the exploration of extraterrestrial
habitability aims to explore the adaptation of terrestrial life in space
conditions for the manned space program and the future interstellar migration,
which shows great scientific significance and public interests. By our
knowledge the early life on Earth, archaea and extremophile have the ability to
adapt to extreme environmental conditions and can potentially habitat in
extraterrestrial environments. Here we proposed a design and framework for the
experiment on exo-ecosystem and extraterrestrial habitability. The conceptual
approach involves building an ecosystem based on archaea and extremophiles in a
simulated extraterrestrial environment, with a focus on assessing the
exobiological potential and adaptability of terrestrial life forms in such
conditions through controlled experiments. Specifically, we introduce the
Chinese Exo-Ecosystem Space Experiment (CHEESE), which investigates the
survivability and potential for sustained growth, reproduction, and ecological
interactions of methanogens under simulated Mars and Moon environments using
the China Space Station (CSS) as a platform. We highlight that the space
station provides unique yet relatively comprehensive conditions for simulating
extraterrestrial environments. In conclusion, space experiments involving
exo-ecosystems could pave the way for long-term human habitation in space,
ensuring our ability to sustain colonies and settlements beyond Earth while
minimizing our ecological impact on celestial bodies
GumDrop at the DISRPT2019 Shared Task: A Model Stacking Approach to Discourse Unit Segmentation and Connective Detection
In this paper we present GumDrop, Georgetown University's entry at the DISRPT
2019 Shared Task on automatic discourse unit segmentation and connective
detection. Our approach relies on model stacking, creating a heterogeneous
ensemble of classifiers, which feed into a metalearner for each final task. The
system encompasses three trainable component stacks: one for sentence
splitting, one for discourse unit segmentation and one for connective
detection. The flexibility of each ensemble allows the system to generalize
well to datasets of different sizes and with varying levels of homogeneity.Comment: Proceedings of Discourse Relation Parsing and Treebanking
(DISRPT2019
Chinese Discourse Annotation Reference Manual
This document provides extensive guidelines and examples for Rhetorical
Structure Theory (RST) annotation in Mandarin Chinese. The guideline is divided
into three sections. We first introduce preprocessing steps to prepare data for
RST annotation. Secondly, we discuss syntactic criteria to segment texts into
Elementary Discourse Units (EDUs). Lastly, we provide examples to define and
distinguish discourse relations in different genres. We hope that this
reference manual can facilitate RST annotations in Chinese and accelerate the
development of the RST framework across languages
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