217 research outputs found
Forward Private Searchable Symmetric Encryption with Optimized I/O Efficiency
Recently, several practical attacks raised serious concerns over the security
of searchable encryption. The attacks have brought emphasis on forward privacy,
which is the key concept behind solutions to the adaptive leakage-exploiting
attacks, and will very likely to become mandatory in the design of new
searchable encryption schemes. For a long time, forward privacy implies
inefficiency and thus most existing searchable encryption schemes do not
support it. Very recently, Bost (CCS 2016) showed that forward privacy can be
obtained without inducing a large communication overhead. However, Bost's
scheme is constructed with a relatively inefficient public key cryptographic
primitive, and has a poor I/O performance. Both of the deficiencies
significantly hinder the practical efficiency of the scheme, and prevent it
from scaling to large data settings. To address the problems, we first present
FAST, which achieves forward privacy and the same communication efficiency as
Bost's scheme, but uses only symmetric cryptographic primitives. We then
present FASTIO, which retains all good properties of FAST, and further improves
I/O efficiency. We implemented the two schemes and compared their performance
with Bost's scheme. The experiment results show that both our schemes are
highly efficient, and FASTIO achieves a much better scalability due to its
optimized I/O
The dependence of the structure of planet-opened gaps in protoplanetary disks on radiative cooling
Planets can excite density waves and open annular gas gaps in protoplanetary
disks. The depth of gaps is influenced by the evolving angular momentum carried
by density waves. While the impact of radiative cooling on the evolution of
density waves has been studied, a quantitative correlation to connect gap depth
with the cooling timescale is lacking. To address this gap in knowledge, we
employ the grid-based code Athena++ to simulate disk-planet interactions,
treating cooling as a thermal relaxation process. We establish quantitative
dependences of steady-state gap depth (Eq. 36) and width (Eq. 41) on planetary
mass, Shakura-Sunyaev viscosity, disk scale height, and thermal relaxation
timescale . We confirm previous results that gap opening is the
weakest when thermal relaxation timescale is comparable to local dynamical
timescale. Significant variations in gap depth, up to an order of magnitude,
are found with different . In terms of width, a gap is at its narrowest
around , approximately to narrower compared to the
isothermal case. When , it can be wider, and higher
viscosity enhances this effect. We derive possible masses of the gas
gap-opening planets in AS 209, HD 163296, MWC 480, and HL Tau, accounting for
the uncertainties in local thermal relaxation timescale.Comment: 19 pages, 16 figures, 4 tables, accepted for publication in Ap
Direct Displacement-based Seismic Design of Glulam Frames with Buckling Restrained Braces
This paper presents a direct displacement-based design (DDBD) approach for the buckling restrained braces (BRBs) braced glue-laminated timber (glulam) frame (BRBGF) structures. First, the critical design parameters of the DDBD approach were derived for BRBGFs. Then, using experimentally verified numerical models, pushover analyses and nonlinear time-history analyses (NLTHAs) were conducted on a series of one-storey BRBGFs to calibrate the stiffness adjustment factor λ for BRB-timber connections and the spectral displacement reduction factor η. Finally, the DDBD approach was verified as a prospective approach for the seismic design of multi-storey BRBGF buildings by NLTHAs of the case study buildings
Interactive Contrastive Learning for Self-supervised Entity Alignment
Self-supervised entity alignment (EA) aims to link equivalent entities across
different knowledge graphs (KGs) without seed alignments. The current SOTA
self-supervised EA method draws inspiration from contrastive learning,
originally designed in computer vision based on instance discrimination and
contrastive loss, and suffers from two shortcomings. Firstly, it puts
unidirectional emphasis on pushing sampled negative entities far away rather
than pulling positively aligned pairs close, as is done in the well-established
supervised EA. Secondly, KGs contain rich side information (e.g., entity
description), and how to effectively leverage those information has not been
adequately investigated in self-supervised EA. In this paper, we propose an
interactive contrastive learning model for self-supervised EA. The model
encodes not only structures and semantics of entities (including entity name,
entity description, and entity neighborhood), but also conducts cross-KG
contrastive learning by building pseudo-aligned entity pairs. Experimental
results show that our approach outperforms previous best self-supervised
results by a large margin (over 9% average improvement) and performs on par
with previous SOTA supervised counterparts, demonstrating the effectiveness of
the interactive contrastive learning for self-supervised EA.Comment: Accepted by CIKM 202
Semantic Segmentation to Extract Coronary Arteries in Invasive Coronary Angiograms
Accurate semantic segmentation of each coronary artery using invasive coronary angiography (ICA) is important for stenosis assessment and coronary artery disease (CAD) diagnosis. In this paper, we propose a multi-step semantic segmentation algorithm based on analyzing arterial segments extracted from ICAs. The proposed algorithm firstly extracts the entire arterial binary mask (binary vascular tree) using a deep learning-based method. Then we extract the centerline of the binary vascular tree and separate it into different arterial segments. Finally, by extracting the underlying arterial topology, position, and pixel features, we construct a powerful coronary artery segment classifier based on a support vector machine. Each arterial segment is classified into the left coronary artery (LCA), left anterior descending (LAD), and other types of arterial segments. The proposed method was tested on a dataset with 225 ICAs and achieved a mean accuracy of 70.33% for the multi-class artery classification and a mean intersection over union of 0.6868 for semantic segmentation of arteries. The experimental results show the effectiveness of the proposed algorithm, which provides impressive performance for analyzing the individual arteries in ICAs
Semantic Segmentation to Extract Coronary Arteries in Invasive Coronary Angiograms
Accurate semantic segmentation of each coronary artery using invasive coronary angiography (ICA) is important for stenosis assessment and coronary artery disease (CAD) diagnosis. In this paper, we propose a multi-step semantic segmentation algorithm based on analyzing arterial sements extraced from ICAs. The proposed algorithm firstly extracts the entire arterial binary mask (binary vascular tree) using a deep learning-based method. Then we extract the centerline of the binary vascular tree and separate it into different arterial segments. Finally, by extracting the underlyingarterial topology, position, and pixel features, we construct a powerful coronary artery segment classifier based on a support vector machine. Each arterial segment is classified into the left coronary artery (LCA), left anterior descending (LAD), and other types of arterial segments. The proposed method was tested on a dataset with 225 ICAs and achieved a mean accuracy of 70.33% for the multi-class artery classification and a mean intersection over union of 0.6868 for semantic segmentation of arteries. The experimental results show the effectiveness of the proposed algorithm, which provides impressive performance for analyzing the individual arteries in ICAs
Semantic Segmentation to Extract Coronary Arteries in Invasive Coronary Angiograms
Accurate semantic segmentation of each coronary artery using invasive coronary angiography (ICA) is important for stenosis assessment and coronary artery disease (CAD) diagnosis. In this paper, we propose a multi-step semantic segmentation algorithm based on analyzing arterial sements extraced from ICAs. The proposed algorithm firstly extracts the entire arterial binary mask (binary vascular tree) using a deep learning-based method. Then we extract the centerline of the binary vascular tree and separate it into different arterial segments. Finally, by extracting the underlyingarterial topology, position, and pixel features, we construct a powerful coronary artery segment classifier based on a support vector machine. Each arterial segment is classified into the left coronary artery (LCA), left anterior descending (LAD), and other types of arterial segments. The proposed method was tested on a dataset with 225 ICAs and achieved a mean accuracy of 70.33% for the multi-class artery classification and a mean intersection over union of 0.6868 for semantic segmentation of arteries. The experimental results show the effectiveness of the proposed algorithm, which provides impressive performance for analyzing the individual arteries in ICAs
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