223 research outputs found
Robust consensus control of uncertain multi-agent systems with input delay: a model reduction method
Design and Simulation Analysis of Bolt Group Connection of BS-Type Flange Cast Steel Right-Angle Sea Valve
BS type flanged cast steel right-angle sea valve is an important valve used to stop the backflow of medium in the ship pipeline system. The valve and the pipeline are connected by a bolt connection. To ensure the reliability of the bolt connection, the theoretical calculation and finite element method are used to verify the reliability of the design of bolt connection. The theoretical result and the result of finite element analysis (using ANSYS) show that the largest stress on the bolt is located in the middle of the bolt. This paper provides solutions for the verifying the design of bolt connection in valves based on comparing the results of theoretical calculation and finite element analysis
Design and Simulation Analysis of Bolt Group Connection of BS-Type Flange Cast Steel Right-Angle Sea Valve
BS type flanged cast steel right-angle sea valve is an important valve used to stop the backflow of medium in the ship pipeline system. The valve and the pipeline are connected by a bolt connection. To ensure the reliability of the bolt connection, the theoretical calculation and finite element method are used to verify the reliability of the design of bolt connection. The theoretical result and the result of finite element analysis (using ANSYS) show that the largest stress on the bolt is located in the middle of the bolt. This paper provides solutions for the verifying the design of bolt connection in valves based on comparing the results of theoretical calculation and finite element analysis
Entity-Aspect-Opinion-Sentiment Quadruple Extraction for Fine-grained Sentiment Analysis
Product reviews often contain a large number of implicit aspects and
object-attribute co-existence cases. Unfortunately, many existing studies in
Aspect-Based Sentiment Analysis (ABSA) have overlooked this issue, which can
make it difficult to extract opinions comprehensively and fairly. In this
paper, we propose a new task called Entity-Aspect-Opinion-Sentiment Quadruple
Extraction (EASQE), which aims to hierarchically decompose aspect terms into
entities and aspects to avoid information loss, non-exclusive annotations, and
opinion misunderstandings in ABSA tasks. To facilitate research in this new
task, we have constructed four datasets (Res14-EASQE, Res15-EASQE, Res16-EASQE,
and Lap14-EASQE) based on the SemEval Restaurant and Laptop datasets. We have
also proposed a novel two-stage sequence-tagging based Trigger-Opinion
framework as the baseline for the EASQE task. Empirical evaluations show that
our Trigger-Opinion framework can generate satisfactory EASQE results and can
also be applied to other ABSA tasks, significantly outperforming
state-of-the-art methods. We have made the four datasets and source code of
Trigger-Opinion publicly available to facilitate further research in this area
Consensus disturbance rejection for Lipschitz nonlinear multi-agent systems with input delay: a DOBC approach
In this paper, a new predictor-based consensus disturbance rejection method is proposed for high-order multi agent systems with Lipschitz nonlinearity and input delay. First, a distributed disturbance observer for consensus control is developed for each agent to estimate the disturbance under the delay constraint. Based on the conventional predictor feedback approach, a non-ideal predictor based control scheme is constructed for each agent by utilizing the estimate of the disturbance and the prediction of the relative state information. Then, rigorous analysis is carried out to ensure that the extra terms associated with disturbances and nonlinear functions are properly considered. Sufficient conditions for the consensus of the multi-agent systems with disturbance rejection are derived based on the analysis in the framework of Lyapunov-Krasovskii functionals. A simulation example is included to demonstrate the performance of the proposed control scheme. (C) 2016 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [61673034]SCI(E)ARTICLE1,SI298-31535
Learning to Detect Noisy Labels Using Model-Based Features
Label noise is ubiquitous in various machine learning scenarios such as
self-labeling with model predictions and erroneous data annotation. Many
existing approaches are based on heuristics such as sample losses, which might
not be flexible enough to achieve optimal solutions. Meta learning based
methods address this issue by learning a data selection function, but can be
hard to optimize. In light of these pros and cons, we propose
Selection-Enhanced Noisy label Training (SENT) that does not rely on meta
learning while having the flexibility of being data-driven. SENT transfers the
noise distribution to a clean set and trains a model to distinguish noisy
labels from clean ones using model-based features. Empirically, on a wide range
of tasks including text classification and speech recognition, SENT improves
performance over strong baselines under the settings of self-training and label
corruption
The role of upfront primary tumor resection in asymptomatic patients with unresectable stage IV colorectal cancer: A systematic review and meta-analysis
BackgroundControversy exists over the role of upfront primary tumor resection (PTR) in asymptomatic patients with unresectable stage IV colorectal cancer (CRC). The purpose of this study was to evaluate the effect of upfront PTR on survival outcomes and adverse outcomes.MethodsSearches were conducted on PubMed, EMBASE, Web of Science, and Cochrane Library from inception to August 2021. Studies comparing survival outcomes with or without adverse outcomes between PTR and non-PTR treatments were included. Review Manager 5.3 was applied for meta-analyses with a random-effects model whenever possible.ResultsOverall, 20 studies with 3,088 patients were finally included in this systematic review. Compared with non-PTR, upfront PTR was associated with better 3-year (HR: 0.69, 95% CI, 0.57–0.83, P = 0.0001) and 5-year overall survival (OS) (HR: 0.77, 95% CI, 0.62–0.95, P = 0.01), while subgroup analysis indicated that there was no significant difference between upfront PTR and upfront chemotherapy (CT) group. In addition, grade 3 or higher adverse effects due to CT were more frequent in the PTR group with marginal significance (OR: 1.74, 95% CI, 0.99–3.06, P = 0.05), and other adverse outcomes were comparable.ConclusionsPTR might be related to improved OS for asymptomatic patients with unresectable stage IV CRC, whereas receiving upfront CT is a rational alternative without detrimental influence on survival or adverse outcomes compared with upfront PTR.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=27267
Risk prediction model establishment with tri-phasic CT image features for differential diagnosis of adrenal pheochromocytomas and lipid-poor adenomas: Grouping method
ObjectivesThe purpose of this study was to establish a risk prediction model for differential diagnosis of pheochromocytomas (PCCs) from lipid-poor adenomas (LPAs) using a grouping method based on tri-phasic CT image features.MethodsIn this retrospective study, we enrolled patients that were assigned to a training set (136 PCCs and 183 LPAs) from two medical centers, along with an external independent validation set (30 PCCs and 54 LPAs) from another center. According to the attenuation values in unenhanced CT (CTu), the lesions were divided into three groups: group 1, 10 HU < CTu ≤ 25 HU; group 2, 25 HU < CTu ≤ 40 HU; and group 3, CTu > 40 HU. Quantitative and qualitative CT imaging features were calculated and evaluated. Univariate, ROC, and binary logistic regression analyses were applied to compare these features.ResultsCystic degeneration, CTu, and the peak value of enhancement in the arterial and venous phase (DEpeak) were independent risk factors for differential diagnosis of adrenal PCCs from LPAs. In all subjects (groups 1, 2, and 3), the model formula for the differentiation of PCCs was as follows: Y = -7.709 + 3.617*(cystic degeneration) + 0.175*(CTu ≥ 35.55 HU) + 0.068*(DEpeak ≥ 51.35 HU). ROC curves were drawn with an AUC of 0.95 (95% CI: 0.927–0.973) in the training set and 0.91 (95% CI: 0.860–0.929) in the external validation set.ConclusionA reliable and practical prediction model for differential diagnosis of adrenal PCCs and LPAs was established using a grouping method
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