315 research outputs found
Restricted Minimum Error Entropy Criterion for Robust Classification
The minimum error entropy (MEE) criterion has been verified as a powerful
approach for non-Gaussian signal processing and robust machine learning.
However, the implementation of MEE on robust classification is rather a vacancy
in the literature. The original MEE only focuses on minimizing the Renyi's
quadratic entropy of the error probability distribution function (PDF), which
could cause failure in noisy classification tasks. To this end, we analyze the
optimal error distribution in the presence of outliers for those classifiers
with continuous errors, and introduce a simple codebook to restrict MEE so that
it drives the error PDF towards the desired case. Half-quadratic based
optimization and convergence analysis of the new learning criterion, called
restricted MEE (RMEE), are provided. Experimental results with logistic
regression and extreme learning machine are presented to verify the desirable
robustness of RMEE
Performance and requirements of GEO SAR systems in the presence of Radio Frequency Interferences
Geosynchronous Synthetic Aperture Radar (GEO SAR) is a possible next generation SAR system, which has the excellent performance of less than one-day revisit and hundreds of kilometres coverage. However, Radio Frequency Interference (RFI) is a serious problem, because the specified primary allocation frequencies are shared by the increasing number of microwave devices. More seriously, as the high orbit of GEO SAR makes the system have a very large imaging swath, the RFI signals all over the illuminated continent will interfere and deteriorate the GEO SAR signal. Aimed at the RFI impact in GEO SAR case, this paper focuses on the performance evaluation and the system design requirement of GEO SAR in the presence of RFI impact. Under the RFI impact, Signal-to-Interference-plus-Noise Ratio (SINR) and the required power are theoretically deduced both for the ground RFI and the bistatic scattering RFI cases. Based on the theoretical analysis, performance evaluations of the GEO SAR design examples in the presence of RFI are conducted. The results show that higher RFI intensity and lower working frequency will make the GEO SAR have a higher power requirement for compensating the RFI impact. Moreover, specular RFI bistatic scattering will give rise to the extremely serious impact on GEO SAR, which needs incredible power requirements for compensations. At last, real RFI signal behaviours and statistical analyses based on the SMOS satellite, Beidou-2 navigation satellite and Sentinel-1 A data have been given in the appendix
The Effect of Race/Ethnicity on the Age of Colon Cancer Diagnosis
ABSTRACT
BACKGROUND: Colorectal cancer is the third most commonly diagnosed cancer in the United States. Notably, racial/ethnic disparities exist in both incidence and mortality.
PURPOSE: The aim of this case study was to investigate the impact of race/ethnicity on age at diagnosis of colorectal cancer in a defined population in Suffolk County, NY.
METHODS: Data were retrospectively collected on race/ethnicity, health insurance status, age at diagnosis, stage at diagnosis, gender, smoking status, alcohol intake, tumor location, and body mass index for colorectal cancer patients with medical records in the Stony Brook University Medical Center database (2005-2011). Population-based data on Hispanic and non-Hispanic Whites were obtained from the Surveillance, Epidemiology, and End Results registry of New York State for an overlapping time period. Permutation-based ANCOVA and logistic regression with stepwise variable selection were conducted to identify covariates and first-order interactions associated with younger age at diagnosis and cancer stage as a dependent categorical variable. RESULTS: Of 328 colorectal cancer patients, Hispanics were diagnosed at a median younger age of 57y vs. 67y than non-Hispanic Whites (FDR = 0.001). Twenty-six percent of Hispanics were diagnosed with colorectal cancer prior to the recommended age (50y) for colorectal cancer surveillance compared to 11% of non-Hispanic Whites (FDR =0.007). Analysis of New York State registry data corroborated our findings that Hispanic colorectal cancer patients were diagnosed at a median younger age than non-Hispanic Whites. Permutation-based ANCOVA identified race/ethnicity and health insurance as significantly associated with age of diagnosis (P=0.001). Logistic regression selected (younger) age at diagnosis as being significantly associated with stage IV disease. The limitations of the case study reside in the use of self-reporting of race and ethnicity and in the small sample sizes.
CONCLUSIONS: Hispanics may be at higher risk for colorectal cancer (y) and younger age at diagnosis is associated with advanced disease
MCNS: Mining Causal Natural Structures Inside Time Series via A Novel Internal Causality Scheme
Causal inference permits us to discover covert relationships of various
variables in time series. However, in most existing works, the variables
mentioned above are the dimensions. The causality between dimensions could be
cursory, which hinders the comprehension of the internal relationship and the
benefit of the causal graph to the neural networks (NNs). In this paper, we
find that causality exists not only outside but also inside the time series
because it reflects a succession of events in the real world. It inspires us to
seek the relationship between internal subsequences. However, the challenges
are the hardship of discovering causality from subsequences and utilizing the
causal natural structures to improve NNs. To address these challenges, we
propose a novel framework called Mining Causal Natural Structure (MCNS), which
is automatic and domain-agnostic and helps to find the causal natural
structures inside time series via the internal causality scheme. We evaluate
the MCNS framework and impregnation NN with MCNS on time series classification
tasks. Experimental results illustrate that our impregnation, by refining
attention, shape selection classification, and pruning datasets, drives NN,
even the data itself preferable accuracy and interpretability. Besides, MCNS
provides an in-depth, solid summary of the time series and datasets.Comment: 9 pages, 6 figure
Sensing as a Service in 6G Perceptive Mobile Networks: Architecture, Advances, and the Road Ahead
Sensing-as-a-service is anticipated to be the core feature of 6G perceptive
mobile networks (PMN), where high-precision real-time sensing will become an
inherent capability rather than being an auxiliary function as before. With the
proliferation of wireless connected devices, resource allocation in terms of
the users' specific quality-of-service (QoS) requirements plays a pivotal role
to enhance the interference management ability and resource utilization
efficiency. In this article, we comprehensively introduce the concept of
sensing service in PMN, including the types of tasks, the
distinctions/advantages compared to conventional networks, and the definitions
of sensing QoS. Subsequently, we provide a unified RA framework in
sensing-centric PMN and elaborate on the unique challenges. Furthermore, we
present a typical case study named "communication-assisted sensing" and
evaluate the performance trade-off between sensing and communication procedure.
Finally, we shed light on several open problems and opportunities deserving
further investigation in the future
Partial Maximum Correntropy Regression for Robust Trajectory Decoding from Noisy Epidural Electrocorticographic Signals
The Partial Least Square Regression (PLSR) exhibits admirable competence for
predicting continuous variables from inter-correlated brain recordings in the
brain-computer interface. However, PLSR is in essence formulated based on the
least square criterion, thus, being non-robust with respect to noises. The aim
of this study is to propose a new robust implementation for PLSR. To this end,
the maximum correntropy criterion (MCC) is used to propose a new robust variant
of PLSR, called as Partial Maximum Correntropy Regression (PMCR). The
half-quadratic optimization is utilized to calculate the robust projectors for
the dimensionality reduction, and the regression coefficients are optimized by
a fixed-point approach. We evaluate the proposed PMCR with a synthetic example
and the public Neurotycho electrocorticography (ECoG) datasets. The extensive
experimental results demonstrate that, the proposed PMCR can achieve better
prediction performance than the conventional PLSR and existing variants with
three different performance indicators in high-dimensional and noisy regression
tasks. PMCR can suppress the performance degradation caused by the adverse
noise, ameliorating the decoding robustness of the brain-computer interface
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