243 research outputs found
On the Characteristics of Ground Motion and the Improvement of the Input Mode of Complex Layered Sites
It is a hot research topic to perform the dynamic interaction analysis between the engineering structure and the soil by using the time-domain method. This paper studies the seismic behaviour of the layered sites and the seismic response of the structures using the viscous-spring artificial boundary theory. The artificial boundary model of viscous-spring is initially based on homogeneous foundation. For the layered site (Foundation), the traditional homogeneous model or equivalent load input mode is not suitable, which may bring great error. By introducing the changes of coefficients and phases of reflection and transmission of seismic waves at the interface between layers, an improved method of equivalent load input mode of traditional viscous-spring artificial boundary model is proposed. This new wave model can simulate the propagation law of seismic wave in layered site more accurately, which is available for the seismic performance of engineering structure under the condition of large and complex layered site. At last, the simplified homogeneous model, the equivalent load input method and the improved layered model input method are used to study the seismic response of the engineering example. It is shown that the results calculated by the three methods are different, which shows that the homogeneous foundation model and the conventional equivalent load input method of seismic wave cannot simulate the seismic force accurately, whereas the improved wave input model can better reflect the characteristic of traveling wave in layered sites
The Simple Criteria of SLOCC Equivalence Classes
We put forward an alternative approach to the SLOCC classification of
entanglement states of three-qubit and four-qubit systems. By directly solving
matrix equations, we obtain the relations satisfied by the amplitudes of
states. The relations are readily tested since in them only addition,
subtraction and multiplication occur.Comment: The original version was submitted to PRA in Feb. 2005, the paper No.
is AA10020. 14 pages for the present version. No figure
Rank-Aware Negative Training for Semi-Supervised Text Classification
Semi-supervised text classification-based paradigms (SSTC) typically employ
the spirit of self-training. The key idea is to train a deep classifier on
limited labeled texts and then iteratively predict the unlabeled texts as their
pseudo-labels for further training. However, the performance is largely
affected by the accuracy of pseudo-labels, which may not be significant in
real-world scenarios. This paper presents a Rank-aware Negative Training (RNT)
framework to address SSTC in learning with noisy label manner. To alleviate the
noisy information, we adapt a reasoning with uncertainty-based approach to rank
the unlabeled texts based on the evidential support received from the labeled
texts. Moreover, we propose the use of negative training to train RNT based on
the concept that ``the input instance does not belong to the complementary
label''. A complementary label is randomly selected from all labels except the
label on-target. Intuitively, the probability of a true label serving as a
complementary label is low and thus provides less noisy information during the
training, resulting in better performance on the test data. Finally, we
evaluate the proposed solution on various text classification benchmark
datasets. Our extensive experiments show that it consistently overcomes the
state-of-the-art alternatives in most scenarios and achieves competitive
performance in the others. The code of RNT is publicly available
at:https://github.com/amurtadha/RNT.Comment: TACL 202
Importance-Aware Image Segmentation-based Semantic Communication for Autonomous Driving
This article studies the problem of image segmentation-based semantic
communication in autonomous driving. In real traffic scenes, detecting the key
objects (e.g., vehicles, pedestrians and obstacles) is more crucial than that
of other objects to guarantee driving safety. Therefore, we propose a vehicular
image segmentation-oriented semantic communication system, termed VIS-SemCom,
where image segmentation features of important objects are transmitted to
reduce transmission redundancy. First, to accurately extract image semantics,
we develop a semantic codec based on Swin Transformer architecture, which
expands the perceptual field thus improving the segmentation accuracy. Next, we
propose a multi-scale semantic extraction scheme via assigning the number of
Swin Transformer blocks for diverse resolution features, thus highlighting the
important objects' accuracy. Furthermore, the importance-aware loss is invoked
to emphasize the important objects, and an online hard sample mining (OHEM)
strategy is proposed to handle small sample issues in the dataset. Experimental
results demonstrate that the proposed VIS-SemCom can achieve a coding gain of
nearly 6 dB with a 60% mean intersection over union (mIoU), reduce the
transmitted data amount by up to 70% with a 60% mIoU, and improve the
segmentation intersection over union (IoU) of important objects by 4%, compared
to traditional transmission scheme.Comment: 10 pages, 8 figure
Automatic Deduction Path Learning via Reinforcement Learning with Environmental Correction
Automatic bill payment is an important part of business operations in fintech
companies. The practice of deduction was mainly based on the total amount or
heuristic search by dividing the bill into smaller parts to deduct as much as
possible. This article proposes an end-to-end approach of automatically
learning the optimal deduction paths (deduction amount in order), which reduces
the cost of manual path design and maximizes the amount of successful
deduction. Specifically, in view of the large search space of the paths and the
extreme sparsity of historical successful deduction records, we propose a deep
hierarchical reinforcement learning approach which abstracts the action into a
two-level hierarchical space: an upper agent that determines the number of
steps of deductions each day and a lower agent that decides the amount of
deduction at each step. In such a way, the action space is structured via prior
knowledge and the exploration space is reduced. Moreover, the inherited
information incompleteness of the business makes the environment just partially
observable. To be precise, the deducted amounts indicate merely the lower
bounds of the available account balance. To this end, we formulate the problem
as a partially observable Markov decision problem (POMDP) and employ an
environment correction algorithm based on the characteristics of the business.
In the world's largest electronic payment business, we have verified the
effectiveness of this scheme offline and deployed it online to serve millions
of users
Traffic-aware multiple mix zone placement for protecting location privacy
Abstract—Privacy protection is of critical concern to Location-Based Service (LBS) users in mobile networks. Long-term pseudonyms, although appear to be anonymous, in fact em-power third-party service providers to continuously track users’ movements. Researchers have proposed the mix zone model to allow pseudonym changes in protected areas. In this paper, we investigate a new form of privacy attack to the LBS system that an adversary reveals a user’s true identity and complete moving tra-jectory with the aid of side information. We propose a new metric to quantify the system’s resilience to such attacks, and suggest using multiple mix zones to tackle this problem. A mathematical model is presented that treats the deployment of multiple mix zones as a cost constrained optimization problem. Furthermore, the influence of traffic density is also taken into account to enhance the protection effectiveness. The placement optimization problem is NP-hard. We therefore design two heuristic algorithms as practical and effective means to strategically select mix zone locations, and consequently reduce the privacy risks of mobile users trajectories. The effectiveness of our proposed solutions is demonstrated through extensive simulations on real-world mobile user data traces. I
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