228 research outputs found
Integrated Water Quality Monitoring of Skaneateles Lake Tributaries
Skaneateles Lake is the drinking water source for the City of Syracuse and surrounding areas. Harmful algal blooms (HABs) have been occurring in Skaneateles Lake every year since 2017 and posing a great threat to water quality and drinking water safety. Although the exact cause of the HABs is still unclear, sunlight, quiescent conditions, warm temperature, and elevated concentrations of nitrogen and phosphorus seem to favor the development of such blooms. In this study, a custom-built, low-cost, multi-parameter sensor unit was designed, built, and deployed on a third-order tributary. The unit collected high-frequency data for stage, temperature, pH, and dissolved oxygen. The unit successfully captured the variability in stream discharge calculated from stage measurements and temperature. The pH and dissolved oxygen sensors performed well during low-flow periods but deviated during high-flow events. Overheating of electronics also contributed to instability in sensor measurements.Grab water samples were collected from nine tributaries and analyzed for total and dissolved organic carbon, phosphorus species, and nitrogen species. Nutrient analysis suggested export of phosphorus and nitrogen during high flow events. Analysis of physical watershed characteristics such as stream order, watershed area, and basin slope, implied that hydrologic flow paths were controlling the concentrations of some carbon, nitrogen, and phosphorus species. This study could provide a blueprint for building low-cost water monitoring systems in non-navigational rivers and contribute to the understanding of how hydrological and nutrient dynamics influences HABs in lakes
An Online Parallel and Distributed Algorithm for Recursive Estimation of Sparse Signals
In this paper, we consider a recursive estimation problem for linear
regression where the signal to be estimated admits a sparse representation and
measurement samples are only sequentially available. We propose a convergent
parallel estimation scheme that consists in solving a sequence of
-regularized least-square problems approximately. The proposed scheme
is novel in three aspects: i) all elements of the unknown vector variable are
updated in parallel at each time instance, and convergence speed is much faster
than state-of-the-art schemes which update the elements sequentially; ii) both
the update direction and stepsize of each element have simple closed-form
expressions, so the algorithm is suitable for online (real-time)
implementation; and iii) the stepsize is designed to accelerate the convergence
but it does not suffer from the common trouble of parameter tuning in
literature. Both centralized and distributed implementation schemes are
discussed. The attractive features of the proposed algorithm are also
numerically consolidated.Comment: Part of this work has been presented at The Asilomar Conference on
Signals, Systems, and Computers, Nov. 201
Stretched Exponential Relaxation of Glasses at Low Temperature
The question of whether glass continues to relax at low temperature is of
fundamental and practical interest. Here, we report a novel atomistic
simulation method allowing us to directly access the long-term dynamics of
glass relaxation at room temperature. We find that the potential energy
relaxation follows a stretched exponential decay, with a stretching exponent
, as predicted by Phillips' diffusion-trap model. Interestingly,
volume relaxation is also found. However, it is not correlated to the energy
relaxation, but is rather a manifestation of the mixed alkali effect
Does Immigration Cause Crime? Evidence from the United States
Donald Trump announced that immigration should be responsible for higher crime incidents in the United States, and he in turn aimed to strengthen his anti-immigrant policies. Recently, his entire anti-immigrant agenda has triggered debates all over the United States. There are not too many previous studies focusing on empirical evidence, and they have never reached a consensus. This paper investigates the relationship between three kinds of immigration and crime in different regional groups to provide an updated assessment, including unauthorized immigrants, foreign population and Mexican unauthorized immigrants.
State level cross-sectional data in 2014 is analyzed using multivariate regression. The results of the regression analysis reveal that immigration has significantly positive effects on violent crime. Compared with foreign population, the influence of unauthorized immigration appears to be stronger. Compared with foreign population and Mexican unauthorized immigrants, the influence of unauthorized immigration appears to be stronger. Contrary to inland state group, the study reveals that immigration accounts for crime. The evidence in fact shows that poverty rate increases the amount of violent crime and crime rate significantly. In the end, the findings provide important implications for the concerned authorities and policymakers
Region based Ensemble Learning Network for Fine-grained Classification
As an important research topic in computer vision, fine-grained
classification which aims to recognition subordinate-level categories has
attracted significant attention. We propose a novel region based ensemble
learning network for fine-grained classification. Our approach contains a
detection module and a module for classification. The detection module is based
on the faster R-CNN framework to locate the semantic regions of the object. The
classification module using an ensemble learning method, which trains a set of
sub-classifiers for different semantic regions and combines them together to
get a stronger classifier. In the evaluation, we implement experiments on the
CUB-2011 dataset and the result of experiments proves our method s efficient
for fine-grained classification. We also extend our approach to remote scene
recognition and evaluate it on the NWPU-RESISC45 dataset.Comment: 6 pages, 3 figures, 2018 Chinese Automation Congress (CAC
FedEdge AI-TC: A Semi-supervised Traffic Classification Method based on Trusted Federated Deep Learning for Mobile Edge Computing
As a typical entity of MEC (Mobile Edge Computing), 5G CPE (Customer Premise
Equipment)/HGU (Home Gateway Unit) has proven to be a promising alternative to
traditional Smart Home Gateway. Network TC (Traffic Classification) is a vital
service quality assurance and security management method for communication
networks, which has become a crucial functional entity in 5G CPE/HGU. In recent
years, many researchers have applied Machine Learning or Deep Learning (DL) to
TC, namely AI-TC, to improve its performance. However, AI-TC faces challenges,
including data dependency, resource-intensive traffic labeling, and user
privacy concerns. The limited computing resources of 5G CPE further complicate
efficient classification. Moreover, the "black box" nature of AI-TC models
raises transparency and credibility issues. The paper proposes the FedEdge
AI-TC framework, leveraging Federated Learning (FL) for reliable Network TC in
5G CPE. FL ensures privacy by employing local training, model parameter
iteration, and centralized training. A semi-supervised TC algorithm based on
Variational Auto-Encoder (VAE) and convolutional neural network (CNN) reduces
data dependency while maintaining accuracy. To optimize model light-weight
deployment, the paper introduces XAI-Pruning, an AI model compression method
combined with DL model interpretability. Experimental evaluation demonstrates
FedEdge AI-TC's superiority over benchmarks in terms of accuracy and efficient
TC performance. The framework enhances user privacy and model credibility,
offering a comprehensive solution for dependable and transparent Network TC in
5G CPE, thus enhancing service quality and security.Comment: 13 pages, 13 figure
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