131 research outputs found
Semiblind Image Deconvolution with Spatially Adaptive Total Variation Regularization
A semiblind image deconvolution algorithm with spatially adaptive total variation (SATV) regularization is introduced. The spatial information in different image regions is incorporated into regularization by using the edge indicator called difference eigenvalue to distinguish flat areas from edges. Meanwhile, the split Bregman method is used to optimize the proposed SATV model. The proposed algorithm integrates the spatial constraint and parametric blur-kernel and thus effectively reduces the noise in flat regions and preserves the edge information. Comparative results on simulated images and real passive millimeter-wave (PMMW) images are reported
A Generalized Cluster-Free NOMA Framework Towards Next-Generation Multiple Access
A generalized downlink multi-antenna non-orthogonal multiple access (NOMA)
transmission framework is proposed with the novel concept of cluster-free
successive interference cancellation (SIC). In contrast to conventional NOMA
approaches, where SIC is successively carried out within the same cluster, the
key idea is that the SIC can be flexibly implemented between any arbitrary
users to achieve efficient interference elimination. Based on the proposed
framework, a sum rate maximization problem is formulated for jointly optimizing
the transmit beamforming and the SIC operations between users, subject to the
SIC decoding conditions and users' minimal data rate requirements. To tackle
this highly-coupled mixed-integer nonlinear programming problem, an alternating
direction method of multipliers-successive convex approximation (ADMM-SCA)
algorithm is developed. The original problem is first reformulated into a
tractable biconvex augmented Lagrangian (AL) problem by handling the non-convex
terms via SCA. Then, this AL problem is decomposed into two subproblems that
are iteratively solved by the ADMM to obtain the stationary solution. Moreover,
to reduce the computational complexity and alleviate the parameter
initialization sensitivity of ADMM-SCA, a Matching-SCA algorithm is proposed.
The intractable binary SIC operations are solved through an extended
many-to-many matching, which is jointly combined with an SCA process to
optimize the transmit beamforming. The proposed Matching-SCA can converge to an
enhanced exchange-stable matching that guarantees the local optimality.
Numerical results demonstrate that: i) the proposed Matching-SCA algorithm
achieves comparable performance and a faster convergence compared to ADMM-SCA;
ii) the proposed generalized framework realizes scenario-adaptive
communications and outperforms traditional multi-antenna NOMA approaches in
various communication regimes.Comment: 30 pages, 9 figures, submitted to IEEE TW
3D-IDS: Doubly Disentangled Dynamic Intrusion Detection
Network-based intrusion detection system (NIDS) monitors network traffic for
malicious activities, forming the frontline defense against increasing attacks
over information infrastructures. Although promising, our quantitative analysis
shows that existing methods perform inconsistently in declaring various unknown
attacks (e.g., 9% and 35% F1 respectively for two distinct unknown threats for
an SVM-based method) or detecting diverse known attacks (e.g., 31% F1 for the
Backdoor and 93% F1 for DDoS by a GCN-based state-of-the-art method), and
reveals that the underlying cause is entangled distributions of flow features.
This motivates us to propose 3D-IDS, a novel method that aims to tackle the
above issues through two-step feature disentanglements and a dynamic graph
diffusion scheme. Specifically, we first disentangle traffic features by a
non-parameterized optimization based on mutual information, automatically
differentiating tens and hundreds of complex features of various attacks. Such
differentiated features will be fed into a memory model to generate
representations, which are further disentangled to highlight the
attack-specific features. Finally, we use a novel graph diffusion method that
dynamically fuses the network topology for spatial-temporal aggregation in
evolving data streams. By doing so, we can effectively identify various attacks
in encrypted traffics, including unknown threats and known ones that are not
easily detected. Experiments show the superiority of our 3D-IDS. We also
demonstrate that our two-step feature disentanglements benefit the
explainability of NIDS.Comment: Accepted and appeared in the proceedings of the KDD 2023 Research
Trac
Giving formulary and drug cost information to providers and impact on medication cost and use: a longitudinal non-randomized study
BackgroundProviders wish to help patients with prescription costs but often lack drug cost information. We examined whether giving providers formulary and drug cost information was associated with changes in their diabetes patients' drug costs and use. We conducted a longitudinal non-randomized evaluation of the web-based Prescribing Guide ( www.PrescribingGuide.com ), a free resource available to Hawaii's providers since 2006, which summarizes the formularies and copayments of six health plans for drugs to treat 16 common health conditions. All adult primary care physicians in Hawaii were offered the Prescribing Guide, and providers who enrolled received a link to the website and regular hardcopy updates.MethodsWe analyzed prescription claims from a large health plan in Hawaii for 5,883 members with diabetes from 2007 (baseline) to 2009 (follow-up). Patients were linked to 299 "main prescribing" providers, who on average, accounted for >88 % of patients' prescriptions and drug costs. We compared changes in drug costs and use for "study" patients whose main provider enrolled to receive the Prescribing Guide, versus "control" patients whose main provider did not enroll to receive the Prescribing Guide.ResultsIn multivariate analyses controlling for provider specialty and clustering of patients by providers, both patient groups experienced similar increases in number of prescriptions (+3.2 vs. +2.7 increase, p = 0.24), and days supply of medications (+141 vs. +129 increase, p = 0.40) averaged across all drugs. Total and out-of-pocket drug costs also increased for both control and study patients. However, control patients showed higher increases in yearly total drug costs of 792 vs. +9.40 vs. +41 vs + 0.23 vs. -$0.19 decrease, p = 0.996).ConclusionGiving formulary and drug cost information to providers was associated with lower increases in total drug costs but not with lower out-of-pocket costs or greater medication use. Insurers and health information technology businesses should continue to increase providers' access to formulary and drug cost information at the point of care
Semantic Entropy Can Simultaneously Benefit Transmission Efficiency and Channel Security of Wireless Semantic Communications
Recently proliferated deep learning-based semantic communications (DLSC)
focus on how transmitted symbols efficiently convey a desired meaning to the
destination. However, the sensitivity of neural models and the openness of
wireless channels cause the DLSC system to be extremely fragile to various
malicious attacks. This inspires us to ask a question: "Can we further exploit
the advantages of transmission efficiency in wireless semantic communications
while also alleviating its security disadvantages?". Keeping this in mind, we
propose SemEntropy, a novel method that answers the above question by exploring
the semantics of data for both adaptive transmission and physical layer
encryption. Specifically, we first introduce semantic entropy, which indicates
the expectation of various semantic scores regarding the transmission goal of
the DLSC. Equipped with such semantic entropy, we can dynamically assign
informative semantics to Orthogonal Frequency Division Multiplexing (OFDM)
subcarriers with better channel conditions in a fine-grained manner. We also
use the entropy to guide semantic key generation to safeguard communications
over open wireless channels. By doing so, both transmission efficiency and
channel security can be simultaneously improved. Extensive experiments over
various benchmarks show the effectiveness of the proposed SemEntropy. We
discuss the reason why our proposed method benefits secure transmission of
DLSC, and also give some interesting findings, e.g., SemEntropy can keep the
semantic accuracy remain 95% with 60% less transmission.Comment: 13 pages, 12 figure
Modeling and simulation of equivalent second-order pendulum model of casting crane based on liquid slosh
Because the load of the foundry crane is the molten metal of high temperature liquid, the liquid in the load will produce different amplitude sloshing during the operation process, showing a complex solid-liquid coupling phenomenon. The conventional modeling method of treating the load as a solid can no longer meet the control requirements. In order to solve this problem, the equivalent second-order pendulum model of liquid sloshing is established in this paper. On this basis, the dynamic equation of casting bridge crane is derived by Lagrange method. Then a sliding mode variable structure controller is designed and simulated. The experimental results verify the dynamic characteristics and effectiveness of the nonlinear model, and realize the precise positioning of the trolley and the effective anti-swing of the load
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