1,521 research outputs found
Chattering-Free Robust Adaptive Sliding Mode Speed Control for Switched Reluctance Motor
This study describes an adaptive sliding mode control (ASMC) for the control of switched reluctance motor (SRM). The main objective is to minimize torque ripples with controller effort smoothness while the system is under perturbation by structured uncertainties, unknown parameters, and external disturbances. The control algorithm employs an adaptive approach to remove the need for prior knowledge within the bound of perturbations. This is suitable for tackling the chattering problem in the sliding motion of ASMC. In order to achieve control effort smoothness and more effective elimination of chattering, the algorithm then incorporates proper modifications in order to build a chattering-free robust adaptive sliding mode control (RASMC) using Lyapunov stability theory. A final advantage of the algorithm is that system stability and error convergence are guaranteed. The effectiveness of the proposed controller in improving robustness and minimizing ripples is demonstrated by numerical simulation. Experimental validation is used to demonstrate the efficiency of the proposed scheme. The results indicate that RASMC provides a superior performance with respect to speed tracking and disturbance rejection over the conventional sliding mode control (CASMC) in the face of uncertainties in model and dynamic loads
Investigating the effect of online service quality of internet duty-free shops on trust and behavioral intention
Purpose: This study seeks to identify the effect of service quality in internet duty-free shops on a customer’s trust and
behavioral intention.
Design/methodology: For this analysis, a survey was executed targeting customers who have used an internet duty-free
shop. A total of 210 questionnaires were analyzed using structural equation modeling.
Findings: The results revealed that a high online service quality experience using an internet duty-free shop had a positive
effect on the customers’ trust. In addition, trust also had a positive effect on the customers’ behavioral intention.
Originality/value: This study is the first paper that examines the effect of online service quality in internet duty-free shops
in Korea. Results of this study could be used as basic data to help establish day to day management strategies for internet
duty-free shops.Peer Reviewe
Robust Distributed Clustering Algorithm Over Multitask Networks
We propose a new adaptive clustering algorithm that is robust to various multitask environments. Positional relationships among optimal vectors and a reference signal are determined by using the mean-square deviation relation derived from a one-step least-mean-square update. Clustering is performed by combining determinations on the positional relationships at several iterations. From this geometrical basis, unlike the conventional clustering algorithms using simple thresholding method, the proposed algorithm can perform clustering accurately in various multitask environments. Simulation results show that the proposed algorithm has more accurate estimation accuracy than the conventional algorithms and is insensitive to parameter selection.11Ysciescopu
Style Blind Domain Generalized Semantic Segmentation via Covariance Alignment and Semantic Consistence Contrastive Learning
Deep learning models for semantic segmentation often experience performance
degradation when deployed to unseen target domains unidentified during the
training phase. This is mainly due to variations in image texture (\ie style)
from different data sources. To tackle this challenge, existing domain
generalized semantic segmentation (DGSS) methods attempt to remove style
variations from the feature. However, these approaches struggle with the
entanglement of style and content, which may lead to the unintentional removal
of crucial content information, causing performance degradation. This study
addresses this limitation by proposing BlindNet, a novel DGSS approach that
blinds the style without external modules or datasets. The main idea behind our
proposed approach is to alleviate the effect of style in the encoder whilst
facilitating robust segmentation in the decoder. To achieve this, BlindNet
comprises two key components: covariance alignment and semantic consistency
contrastive learning. Specifically, the covariance alignment trains the encoder
to uniformly recognize various styles and preserve the content information of
the feature, rather than removing the style-sensitive factor. Meanwhile,
semantic consistency contrastive learning enables the decoder to construct
discriminative class embedding space and disentangles features that are
vulnerable to misclassification. Through extensive experiments, our approach
outperforms existing DGSS methods, exhibiting robustness and superior
performance for semantic segmentation on unseen target domains.Comment: CVPR 202
Anti-Apoptotic Effects of SERPIN B3 and B4 via STAT6 Activation in Macrophages after Infection with Toxoplasma gondii
Toxoplasma gondii penetrates all kinds of nucleated eukaryotic cells but modulates host cells differently for its intracellular survival. In a previous study, we found out that serine protease inhibitors B3 and B4 (SERPIN B3/B4 because of their very high homology) were significantly induced in THP-1-derived macrophages infected with T. gondii through activation of STAT6. In this study, to evaluate the effects of the induced SERPIN B3/B4 on the apoptosis of T. gondii-infected THP-1 cells, we designed and tested various small interfering (si-) RNAs of SERPIN B3 or B4 in staurosporine-induced apoptosis of THP-1 cells. Anti-apoptotic characteristics of THP-1 cells after infection with T. gondii disappeared when SERPIN B3/B4 were knock-downed with gene specific si-RNAs transfected into THP-1 cells as detected by the cleaved caspase 3, poly-ADP ribose polymerase and DNA fragmentation. This anti-apoptotic effect was confirmed in SERPIN B3/B4 overexpressed HeLa cells. We also investigated whether inhibition of STAT6 affects the function of SERPIN B3/B4, and vice versa. Inhibition of SERPIN B3/B4 did not influence STAT6 expression but SERPIN B3/B4 expression was inhibited by STAT6 si-RNA transfection, which confirmed that SERPIN B3/B4 was induced under the control of STAT6 activation. These results suggest that T. gondii induces SERPIN B3/B4 expression via STAT6 activation to inhibit the apoptosis of infected THP-1 cells for longer survival of the intracellular parasites themselves
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