247 research outputs found
Exponential Mixing for Retarded Stochastic Differential Equations
In this paper, we discuss exponential mixing property for Markovian
semigroups generated by segment processes associated with several class of
retarded Stochastic Differential Equations (SDEs) which cover SDEs with
constant/variable/distributed time-lags. In particular, we investigate the
exponential mixing property for (a) non-autonomous retarded SDEs by the
Arzel\`{a}--Ascoli tightness characterization of the space \C equipped with
the uniform topology (b) neutral SDEs with continuous sample paths by a
generalized Razumikhin-type argument and a stability-in-distribution approach
and (c) jump-diffusion retarded SDEs by the Kurtz criterion of tightness for
the space \D endowed with the Skorohod topology.Comment: 20 page
MSMG-Net: Multi-scale Multi-grained Supervised Metworks for Multi-task Image Manipulation Detection and Localization
With the rapid advances of image editing techniques in recent years, image
manipulation detection has attracted considerable attention since the
increasing security risks posed by tampered images. To address these
challenges, a novel multi-scale multi-grained deep network (MSMG-Net) is
proposed to automatically identify manipulated regions. In our MSMG-Net, a
parallel multi-scale feature extraction structure is used to extract
multi-scale features. Then the multi-grained feature learning is utilized to
perceive object-level semantics relation of multi-scale features by introducing
the shunted self-attention. To fuse multi-scale multi-grained features, global
and local feature fusion block are designed for manipulated region segmentation
by a bottom-up approach and multi-level feature aggregation block is designed
for edge artifacts detection by a top-down approach. Thus, MSMG-Net can
effectively perceive the object-level semantics and encode the edge artifact.
Experimental results on five benchmark datasets justify the superior
performance of the proposed method, outperforming state-of-the-art manipulation
detection and localization methods. Extensive ablation experiments and feature
visualization demonstrate the multi-scale multi-grained learning can present
effective visual representations of manipulated regions. In addition, MSMG-Net
shows better robustness when various post-processing methods further manipulate
images
Higher-order Oscillatory Planar Hall Effect in Topological Kagome Metal
Exploration of exotic transport behavior for quantum materials is of great
interest and importance for revealing exotic orders to bring new physics. In
this Letter, we report the observation of exotic prominent planar Hall effect
(PHE) and planar anisotropic magnetoresistivity (PAMR) in strange kagome metal
KVSb. The PHE and PAMR, which are driven by an in-plane magnetic field
and display sharp difference from other Hall effects driven by an out-of-plane
magnetic field or magnetization, exhibit exotic higher-order oscillations in
sharp contrast to those following empirical rule only allowing twofold
symmetrical oscillations. These higher-order oscillations exhibit strong field
and temperature dependence and vanish around charge density wave (CDW)
transition. The unique transport properties suggest a significant interplay of
the lattice, magnetic and electronic structure in KVSb. This interplay
can couple the hidden anisotropy and transport electrons leading to the novel
PHE and PAMR in contrast to other materials
Magneto-Transport Properties of Kagome Magnet TmMnSn
Kagome magnet usually hosts nontrivial electronic or magnetic states drawing
great interests in condensed matter physics. In this paper, we report a
systematic study on transport properties of kagome magnet TmMnSn. The
prominent topological Hall effect (THE) has been observed in a wide temperature
region spanning over several magnetic phases and exhibits strong temperature
and field dependence. This novel phenomenon due to non-zero spin chirality
indicates possible appearance of nontrival magnetic states accompanying with
strong fluctuations. The planar applied field drives planar Hall effect(PHE)
and anistropic magnetoresisitivity(PAMR) exhibiting sharp disconnections in
angular dependent planar resistivity violating the empirical law. By using an
effective field, we identify a magnetic transition separating the PAMR into two
groups belonging to various magnetic states. We extended the empirical formula
to scale the field and temperature dependent planar magnetoresistivity and
provide the understandings for planar transport behaviors with the crossover
between various magnetic states. Our results shed lights on the novel transport
effects in presence of multiple nontrivial magnetic states for the kagome
lattice with complicated magnetic structures
Structural and electronic origin of the magnetic structures in hexagonal LuFeO
Using combined theoretical and experimental approaches, we studied the
structural and electronic origin of the magnetic structure in hexagonal
LuFeO. Besides showing the strong exchange coupling that is consistent with
the high magnetic ordering temperature, the previously observed spin
reorientation transition is explained by the theoretically calculated magnetic
phase diagram. The structural origin of this spin reorientation that is
responsible for the appearance of spontaneous magnetization, is identified by
theory and verified by x-ray diffraction and absorption experiments.Comment: 5 pages, 2 tables and 4 figures, Please contact us for the
supplementary material. Accepted in Phys. Rev. B, in productio
Aftertreatment control and adaptation for automotive lean burn engines with HEGO sensors
Control of aftertreatment systems for lean burn technology engines represents a big challenge, due to the lack of on-board emission measurements and the sensitivity of the hardware components to ageing and sulphur poisoning. In this paper, we consider the control and adaptation of aftertreatment systems involving lean NO x trap (LNT). A phenomenological LNT model is presented to facilitate the model-based control and adaptation. A control strategy based on the LNT model and HEGO (heated exhaust gas oxygen) sensor feedback is discussed. A linear parametric model, which is derived by exploiting the physical properties of the LNT is used for adaptation of trap capacity and feedgas NO x emission models. The conditions under which parameter convergence will be achieved are derived for the proposed adaptive scheme. Simulation results for different scenarios are included to demonstrate the effectiveness of control and adaptation. Copyright © 2004 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35013/1/786_ftp.pd
Time-shared channel identification for adaptive noise cancellation in breath sound extraction
Abstract: Noise artifacts are one of the key obstacles in applying continuous monitoring and conrputer-assisted analysis of lung sounds. Traditional adaptive noise cancellation (ANC) methodologies work reasonably well when signal and noise are stationary and independent. Clinical lung sound auscultation encounters an acoustic environment in which breath sounds are not stationary and often correlate with noise. Consequently, capability of ANC becomes significantly compromised. This paper introduces a new methodology for extracting authentic lung sounds from noise-corrupted measurements. Unlike traditional noise cancellation methods that rely on either frequency band separation or sig3M/noise independence to achieve noise reduction, this methodology combines the traditional noise canceling n{ethods with the unique feature of time-split stages in breathing sounds. By employing a multi-sensor system, the method first employs a high-pass filter to elhninate the off-hand noise, and then performs time-shared blind identification and noise cancellation with recursion from breathing cycle to cycle. Since no frequency separation or signal/noise independence is required, this method potentially has a robust and reliable capability of noise reduction, complementing the traditional methods
Identifying Plant Pentatricopeptide Repeat Coding Gene/Protein Using Mixed Feature Extraction Methods
Motivation: Pentatricopeptide repeat (PPR) is a triangular pentapeptide repeat domain that plays a vital role in plant growth. In this study, we seek to identify PPR coding genes and proteins using a mixture of feature extraction methods. We use four single feature extraction methods focusing on the sequence, physical, and chemical properties as well as the amino acid composition, and mix the features. The Max-Relevant-Max-Distance (MRMD) technique is applied to reduce the feature dimension. Classification uses the random forest, J48, and naïve Bayes with 10-fold cross-validation.Results: Combining two of the feature extraction methods with the random forest classifier produces the highest area under the curve of 0.9848. Using MRMD to reduce the dimension improves this metric for J48 and naïve Bayes, but has little effect on the random forest results.Availability and Implementation: The webserver is available at: http://server.malab.cn/MixedPPR/index.jsp
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