513 research outputs found
The Seven Sins as told in verses by Edmund Spencer
https://digitalcommons.risd.edu/specialcollections_bookcontest9th2023/1002/thumbnail.jp
Ionospheric clutter models for high frequency surface wave radar
High frequency surface wave radar (HFSWR), operating at frequencies between 3 and
30 MHz, has long been employed as an important ocean remote sensing device. These high
frequency (HF) radars can provide accurate and real-time information for sea state monitoring
and hard-target detection, which is greatly beneficial for planning and executing
oceanographic projects, search and rescue events, and other commercial marine activities.
Ideally, in HFSWR operation, the radio waves may be coupled with ocean waves and propagate
along the curvature of the ocean surface with ranges well beyond 200 km. However,
during transmission, a portion of the radar radiation may travel upwards to the ionosphere
from the transmitting antenna. This may be partially reflected back to the receiving antennas
directly (vertical propagation) or via the ocean surface (mixed-path propagation). This
ionospheric clutter may significantly impact the performance of HFSWR. Furthermore, the
high intensity and random behaviour of the ionospheric spectral contamination of radar
echoes make the suppression of this kind of clutter challenging.
In this thesis, comprehensive theoretical models of the ionospheric clutter are investigated.
The physical influences of the ionospheric electron density on HF radar Doppler
spectra are taken into account in the ionospheric reflection coefficient. Next, based on previous
modeling involving the scattering of HF electromagnetic radiation from the ocean
surface and a first-order mixed-path propagation theory, the second-order received electric
field for mixed-path propagation is derived for a monostatic radar configuration. This is
done by considering the reflection from the ionosphere and scattering on the ocean surface
with second-order sea waves. Then, the field integrals are taken to the time domain, with
the source field being that of a vertically polarized pulsed dipole antenna. Subsequently, the second-order received power model is developed by assuming that the ocean surface and
the ionosphere may be modeled as stochastic processes.
The ionospheric clutter model including a pulsed radar source is further investigated for
the case of vertical propagation for a monostatic configuration and mixed-path propagation
for a bistatic configuration.
Next, a theoreticalmixed-path propagationmodel is developed by involving a frequencymodulated
continuous waveform (FMCW) radar source.
In order to investigate the power spectrum of the resulting ionospheric clutter and its
relative intensity to that of the first-order ocean clutter, the normalized ionospheric clutter
power is simulated. Numerical simulation results are provided to indicate the performance
of the ionospheric clutter under a variety of radar operating parameters, ionospheric conditions
and sea states
Use of Structural Equation Modelling and Neural Network to Analyse Shared Parking Choice Behaviour
The shared parking mode represents a feasible solution to the persistent problem of parking scarcity in urban areas. This paper aims to examine the shared parking choice behaviours using a combination of structural equation modelling (SEM) and neural network, taking into account both the parking location characteristics and the travellers’ characteristics. Data were collected from a commercial district in Nanjing, China, through an online questionnaire survey covering 11 factors affecting shared parking choice. The method involved two steps: firstly, SEM was applied to examine the influence of these factors on shared parking choice. Following this, the seven factors with the strongest correlation to shared parking choice were used to train a neural network model for shared parking prediction. This SEM-informed model was found to outperform a neural network model trained on all eleven factors across precision, recall, accuracy, F1 and AUC metrics. The research concluded that the selected factors significantly influence shared parking choice, reinforcing the hypothesis regarding the importance of parking location and traveller characteristics. These findings provide valuable insights to support the effective implementation and promotion of shared parking
A Book of Happiness
https://digitalcommons.risd.edu/bookcontest_supplementalcontent/1023/thumbnail.jp
Enhancing Deep Knowledge Tracing with Auxiliary Tasks
Knowledge tracing (KT) is the problem of predicting students' future
performance based on their historical interactions with intelligent tutoring
systems. Recent studies have applied multiple types of deep neural networks to
solve the KT problem. However, there are two important factors in real-world
educational data that are not well represented. First, most existing works
augment input representations with the co-occurrence matrix of questions and
knowledge components\footnote{\label{ft:kc}A KC is a generalization of everyday
terms like concept, principle, fact, or skill.} (KCs) but fail to explicitly
integrate such intrinsic relations into the final response prediction task.
Second, the individualized historical performance of students has not been well
captured. In this paper, we proposed \emph{AT-DKT} to improve the prediction
performance of the original deep knowledge tracing model with two auxiliary
learning tasks, i.e., \emph{question tagging (QT) prediction task} and
\emph{individualized prior knowledge (IK) prediction task}. Specifically, the
QT task helps learn better question representations by predicting whether
questions contain specific KCs. The IK task captures students' global
historical performance by progressively predicting student-level prior
knowledge that is hidden in students' historical learning interactions. We
conduct comprehensive experiments on three real-world educational datasets and
compare the proposed approach to both deep sequential KT models and
non-sequential models. Experimental results show that \emph{AT-DKT} outperforms
all sequential models with more than 0.9\% improvements of AUC for all
datasets, and is almost the second best compared to non-sequential models.
Furthermore, we conduct both ablation studies and quantitative analysis to show
the effectiveness of auxiliary tasks and the superior prediction outcomes of
\emph{AT-DKT}.Comment: Accepted at WWW'23: The 2023 ACM Web Conference, 202
Influence of chemical oxidant on degradation of benzo[a]pyrene metabolites by the bacterium-Zoogloea sp.
It is neither comprehensive nor appropriate that the bioremediation of a benzo[a]pyrene (BaP)-contaminated environment be assessed only by its high degradation extent because its metabolites\u27 chemical structures are similar to the parent compound and maybe equally toxic. Therefore, further degradation of BaP metabolites is significant. Three methods, combining the Zoogloea sp. with potassium permanganate, combining the Zoogloea sp. with H2O2, Zoogloea sp. alone, were investigated to degrade cis-BP4,5-dihydrodiol and cis-BP7,8-dihydrodiol, which are the metabolites of BaP formed by bacterium-Zoogloea sp. Optimum parameters of degradation in the best method are that: of the three methods, coupling the Zoogloea sp. and KMnO4 is the best; compared with cis-BP7,8-dihydrodiol, cis-BP4,5-dihydrodiol is the more liable to be accumulated in pure cultures; the degradation effect of the two metabolites is optimal when the initial concentration of KMnO4 in the cultures is 0.05%; initial concentration of cis-BP4,5-dihydrodiol and cis-BP7,8-dihydrodiol is 4 mg L−1, 8 mg L−1, respectively; cometabolic substance is salicylic acid or sodium succinate. The degradation extent of cis-BP4,5-dihydrodiol and cis-BP7,8-dihydrodiol using combining the Zoogloea sp. and KMnO4 reach 76.1% and 85.9% after 12 days of cultivation, respectively, which were more than twice compared with conventional method.<br /
Pipeline for precise insoluble matrisome coverage in tissue extracellular matrices
The extracellular matrix (ECM) is assembled by hundreds of proteins orchestrating tissue patterning and surrounding cell fates via the mechanical–biochemical feedback loop. Aberrant ECM protein production or assembly usually creates pathological niches eliciting lesions that mainly involve fibrogenesis and carcinogenesis. Yet, our current knowledge about the pathophysiological ECM compositions and alterations in healthy or diseased tissues is limited since the methodology for precise insoluble matrisome coverage in the ECM is a “bottleneck.” Our current study proposes an enhanced sodium dodecyl sulfonate (E-SDS) workflow for thorough tissue decellularization and an intact pipeline for the accurate identification and quantification of highly insoluble ECM matrisome proteins. We tested this pipeline in nine mouse organs and highlighted the full landscape of insoluble matrisome proteins in the decellularized ECM (dECM) scaffolds. Typical experimental validations and mass spectrometry (MS) analysis confirmed very little contamination of cellular debris remaining in the dECM scaffolds. Our current study will provide a low-cost, simple, reliable, and effective pipeline for tissue insoluble matrisome analysis in the quest to comprehend ECM discovery proteomic studies
Wavelet Entropy and Complexity Analysis for Drinkers' EEG
This paper investigates the influence of alcohol on brain complexity. Considering electroencephalogram (EEG) has the nonlinear dynamics characteristic of time-varying and non-stationary, the wavelet entropy (WE) analysis is introduced. The EEG data of drinkers' and normal people's is analyzed using the wavelet entropy. The results show that the EEG wavelet entropy of drinkers' is markedly greater than the EEG wavelet entropy of normal people's, The EEG complexity of drinkers' is higher and the brain of drinkers' is in a more chaotic state
Multiple Naïve Bayes Classifiers Ensemble for Traffic Incident Detection
This study presents the applicability of the Naïve Bayes classifier ensemble for traffic incident detection. The standard Naive Bayes (NB) has been applied to traffic incident detection and has achieved good results. However, the detection result of the practically implemented NB depends on the choice of the optimal threshold, which is determined mathematically by using Bayesian concepts in the incident-detection process. To avoid the burden of choosing the optimal threshold and tuning the parameters and, furthermore, to improve the limited classification performance of the NB and to enhance the detection performance, we propose an NB classifier ensemble for incident detection. In addition, we also propose to combine the Naïve Bayes and decision tree (NBTree) to detect incidents. In this paper, we discuss extensive experiments that were performed to evaluate the performances of three algorithms: standard NB, NB ensemble, and NBTree. The experimental results indicate that the performances of five rules of the NB classifier ensemble are significantly better than those of standard NB and slightly better than those of NBTree in terms of some indicators. More importantly, the performances of the NB classifier ensemble are very stable
Prioritizing protein complexes implicated in human diseases by network optimization.
BACKGROUND: The detection of associations between protein complexes and human inherited diseases is of great importance in understanding mechanisms of diseases. Dysfunctions of a protein complex are usually defined by its member disturbance and consequently result in certain diseases. Although individual disease proteins have been widely predicted, computational methods are still absent for systematically investigating disease-related protein complexes.
RESULTS: We propose a method, MAXCOM, for the prioritization of candidate protein complexes. MAXCOM performs a maximum information flow algorithm to optimize relationships between a query disease and candidate protein complexes through a heterogeneous network that is constructed by combining protein-protein interactions and disease phenotypic similarities. Cross-validation experiments on 539 protein complexes show that MAXCOM can rank 382 (70.87%) protein complexes at the top against protein complexes constructed at random. Permutation experiments further confirm that MAXCOM is robust to the network structure and parameters involved. We further analyze protein complexes ranked among top ten for breast cancer and demonstrate that the SWI/SNF complex is potentially associated with breast cancer.
CONCLUSIONS: MAXCOM is an effective method for the discovery of disease-related protein complexes based on network optimization. The high performance and robustness of this approach can facilitate not only pathologic studies of diseases, but also the design of drugs targeting on multiple proteins
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