492 research outputs found
Does generalization performance of regularization learning depend on ? A negative example
-regularization has been demonstrated to be an attractive technique in
machine learning and statistical modeling. It attempts to improve the
generalization (prediction) capability of a machine (model) through
appropriately shrinking its coefficients. The shape of a estimator
differs in varying choices of the regularization order . In particular,
leads to the LASSO estimate, while corresponds to the smooth
ridge regression. This makes the order a potential tuning parameter in
applications. To facilitate the use of -regularization, we intend to
seek for a modeling strategy where an elaborative selection on is
avoidable. In this spirit, we place our investigation within a general
framework of -regularized kernel learning under a sample dependent
hypothesis space (SDHS). For a designated class of kernel functions, we show
that all estimators for attain similar generalization
error bounds. These estimated bounds are almost optimal in the sense that up to
a logarithmic factor, the upper and lower bounds are asymptotically identical.
This finding tentatively reveals that, in some modeling contexts, the choice of
might not have a strong impact in terms of the generalization capability.
From this perspective, can be arbitrarily specified, or specified merely by
other no generalization criteria like smoothness, computational complexity,
sparsity, etc..Comment: 35 pages, 3 figure
The Impact of Enterprise Social Media Use on Overload: The Moderating Role of Communication Visibility
Prior research has mainly focused on the positive effects of information technology (IT) use. However, emerging research begins to highlight the importance of considering the dark side of IT use. This study examines how enterprise social media (ESM) use (i.e., work- and social- related use) affects employees’ perceived overload (i.e., information and social overload). In addition, we propose that communication visibility moderates the nonlinear relationship between ESM use and overload. The theoretical and practical implications are also discussed
ASPIE: A Framework for Active Sensing and Processing of Complex Events in the Internet of Manufacturing Things
Rapid perception and processing of critical monitoring events are essential to ensure healthy operation of Internet of Manufacturing Things (IoMT)-based manufacturing processes. In this paper, we proposed a framework (active sensing and processing architecture (ASPIE)) for active sensing and processing of critical events in IoMT-based manufacturing based on the characteristics of IoMT architecture as well as its perception model. A relation model of complex events in manufacturing processes, together with related operators and unified XML-based semantic definitions, are developed to effectively process the complex event big data. A template based processing method for complex events is further introduced to conduct complex event matching using the Apriori frequent item mining algorithm. To evaluate the proposed models and methods, we developed a software platform based on ASPIE for a local chili sauce manufacturing company, which demonstrated the feasibility and effectiveness of the proposed methods for active perception and processing of complex events in IoMT-based manufacturing
SpectralDiff: A Generative Framework for Hyperspectral Image Classification with Diffusion Models
Hyperspectral Image (HSI) classification is an important issue in remote
sensing field with extensive applications in earth science. In recent years, a
large number of deep learning-based HSI classification methods have been
proposed. However, existing methods have limited ability to handle
high-dimensional, highly redundant, and complex data, making it challenging to
capture the spectral-spatial distributions of data and relationships between
samples. To address this issue, we propose a generative framework for HSI
classification with diffusion models (SpectralDiff) that effectively mines the
distribution information of high-dimensional and highly redundant data by
iteratively denoising and explicitly constructing the data generation process,
thus better reflecting the relationships between samples. The framework
consists of a spectral-spatial diffusion module, and an attention-based
classification module. The spectral-spatial diffusion module adopts forward and
reverse spectral-spatial diffusion processes to achieve adaptive construction
of sample relationships without requiring prior knowledge of graphical
structure or neighborhood information. It captures spectral-spatial
distribution and contextual information of objects in HSI and mines
unsupervised spectral-spatial diffusion features within the reverse diffusion
process. Finally, these features are fed into the attention-based
classification module for per-pixel classification. The diffusion features can
facilitate cross-sample perception via reconstruction distribution, leading to
improved classification performance. Experiments on three public HSI datasets
demonstrate that the proposed method can achieve better performance than
state-of-the-art methods. For the sake of reproducibility, the source code of
SpectralDiff will be publicly available at
https://github.com/chenning0115/SpectralDiff
Uncertainty Quantification for Hyperspectral Image Denoising Frameworks based on Low-rank Matrix Approximation
Sliding-window based low-rank matrix approximation (LRMA) is a technique
widely used in hyperspectral images (HSIs) denoising or completion. However,
the uncertainty quantification of the restored HSI has not been addressed to
date. Accurate uncertainty quantification of the denoised HSI facilitates to
applications such as multi-source or multi-scale data fusion, data
assimilation, and product uncertainty quantification, since these applications
require an accurate approach to describe the statistical distributions of the
input data. Therefore, we propose a prior-free closed-form element-wise
uncertainty quantification method for LRMA-based HSI restoration. Our
closed-form algorithm overcomes the difficulty of the HSI patch mixing problem
caused by the sliding-window strategy used in the conventional LRMA process.
The proposed approach only requires the uncertainty of the observed HSI and
provides the uncertainty result relatively rapidly and with similar
computational complexity as the LRMA technique. We conduct extensive
experiments to validate the estimation accuracy of the proposed closed-form
uncertainty approach. The method is robust to at least 10% random impulse noise
at the cost of 10-20% of additional processing time compared to the LRMA. The
experiments indicate that the proposed closed-form uncertainty quantification
method is more applicable to real-world applications than the baseline Monte
Carlo test, which is computationally expensive. The code is available in the
attachment and will be released after the acceptance of this paper.Comment: Accepted for publication by IEEE Transactions on Geoscience and
Remote Sensing. IEEE Transactions on Geoscience and Remote Sensing (TGRS
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