Performance Analysis
Hyperdimensional Feature Fusion for Out-Of-Distribution Detection
Wilson, Samuel, Sünderhauf, Niko, Dayoub, Feras
We introduce powerful ideas from Hyperdimensional Computing into the challenging field of Out-of-Distribution (OOD) detection. In contrast to most existing work that performs OOD detection based on only a single layer of a neural network, we use similarity-preserving semi-orthogonal projection matrices to project the feature maps from multiple layers into a common vector space. By repeatedly applying the bundling operation $\oplus$, we create expressive class-specific descriptor vectors for all in-distribution classes. At test time, a simple and efficient cosine similarity calculation between descriptor vectors consistently identifies OOD samples with better performance than the current state-of-the-art. We show that the hyperdimensional fusion of multiple network layers is critical to achieve best general performance.
Researchers explain why they believe Facebook mishandles political ads
Facebook has worked for years to revamp its handling of political ads -- but researchers who conducted a comprehensive audit of millions of ads say the social media company's efforts have had uneven results. The problems, they say, include overcounting political ads in the U.S. -- and undercounting them in other countries. And despite Facebook's ban on political ads around the time of last year's U.S. elections, the platform allowed more than 70,000 political ads to run anyway, according to the research team that is based at the NYU Cybersecurity for Democracy and at the Belgian university KU Leuven. Their research study was released early Thursday. They also plan to present their findings at a security conference next August.
How AI could help screen for autism in children
For children with autism spectrum disorder (ASD), receiving an early diagnosis can make a huge difference in improving behavior, skills and language development. There is no lab test and no single identified genetic cause--instead, clinicians look at the child's behavior and conduct structured interviews with the child's caregivers based on questionnaires. But these questionnaires are extensive, complicated and not foolproof. "In trying to discern and stratify a complex condition such as autism spectrum disorder, knowing what questions to ask and in what order becomes challenging," said USC University Professor Shrikanth Narayanan, Niki and Max Nikias Chair in Engineering and professor of electrical and computer engineering, computer science, linguistics, psychology, pediatrics and otolaryngology. "As such, this system is difficult to administer and can produce false positives, or confound ASD as other comorbid conditions, such as attention deficit hyperactivity disorder (ADHD)."
A survey on multi-objective hyperparameter optimization algorithms for Machine Learning
Morales-Hernández, Alejandro, Van Nieuwenhuyse, Inneke, Gonzalez, Sebastian Rojas
Hyperparameter optimization (HPO) is a necessary step to ensure the best possible performance of Machine Learning (ML) algorithms. Several methods have been developed to perform HPO; most of these are focused on optimizing one performance measure (usually an error-based measure), and the literature on such single-objective HPO problems is vast. Recently, though, algorithms have appeared which focus on optimizing multiple conflicting objectives simultaneously. This article presents a systematic survey of the literature published between 2014 and 2020 on multi-objective HPO algorithms, distinguishing between metaheuristic-based algorithms, metamodel-based algorithms, and approaches using a mixture of both. We also discuss the quality metrics used to compare multi-objective HPO procedures and present future research directions.
A Comparative Analysis of Machine Learning Techniques for IoT Intrusion Detection
Vitorino, João, Andrade, Rui, Praça, Isabel, Sousa, Orlando, Maia, Eva
The digital transformation faces tremendous security challenges. In particular, the growing number of cyber-attacks targeting Internet of Things (IoT) systems restates the need for a reliable detection of malicious network activity. This paper presents a comparative analysis of supervised, unsupervised and reinforcement learning techniques on nine malware captures of the IoT-23 dataset, considering both binary and multi-class classification scenarios. The developed models consisted of Support Vector Machine (SVM), Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), Isolation Forest (iForest), Local Outlier Factor (LOF) and a Deep Reinforcement Learning (DRL) model based on a Double Deep Q-Network (DDQN), adapted to the intrusion detection context. The most reliable performance was achieved by LightGBM. Nonetheless, iForest displayed good anomaly detection results and the DRL model demonstrated the possible benefits of employing this methodology to continuously improve the detection. Overall, the obtained results indicate that the analyzed techniques are well suited for IoT intrusion detection.
Differentially Private Ensemble Classifiers for Data Streams
Gondara, Lovedeep, Wang, Ke, Carvalho, Ricardo Silva
To further add to the challenge, data streams from many domains involve sensitive, personal information about contributing Learning from continuous data streams via classification/regression users, such as patients' records and user data in mobile applications, is prevalent in many domains. Adapting to evolving data characteristics protection of which is of paramount interest. While concept (concept drift) while protecting data owners' private information drift and privacy have been extensively studied in isolation, works is an open challenge. We present a differentially private considering both are in infancy. See more discussion in Section ensemble solution to this problem with two distinguishing features: 2. In this work, our goal is to allow machine learning models to it allows an unbounded number of ensemble updates to deal with deal with concept drift when training on potentially never-ending the potentially never-ending data streams under a fixed privacy data streams involving sensitive data, where the model(s) learned budget, and it is model agnostic, in that it treats any pre-trained can be published without disclosing sensitive information.
Prediction of Adverse Biological Effects of Chemicals Using Knowledge Graph Embeddings
Myklebust, Erik B., Jiménez-Ruiz, Ernesto, Chen, Jiaoyan, Wolf, Raoul, Tollefsen, Knut Erik
We have created a knowledge graph based on major data sources used in ecotoxicological risk assessment. We have applied this knowledge graph to an important task in risk assessment, namely chemical effect prediction. We have evaluated nine knowledge graph embedding models from a selection of geometric, decomposition, and convolutional models on this prediction task. We show that using knowledge graph embeddings can increase the accuracy of effect prediction with neural networks. Furthermore, we have implemented a fine-tuning architecture which adapts the knowledge graph embeddings to the effect prediction task and leads to a better performance. Finally, we evaluate certain characteristics of the knowledge graph embedding models to shed light on the individual model performance.
Naive Bayes Classifier Spam Filter Example : 4 Easy Steps
In probability, Bayes is a type of conditional probability. It predicts the event based on an event that has already happened. You can use Naive Bayes as a supervised machine learning method for predicting the event based on the evidence present in your dataset. In this tutorial, you will learn how to classify the email as spam or not using the Naive Bayes Classifier. Before doing coding demonstration, Let's know about the Naive Bayes in a brief.
Every Single Way You Can Tell Trump World Is Lying About Its Latest COVID Scandal
Donald Trump and his former White House chief of staff Mark Meadows are peddling a new story about the ex-president's coronavirus infection. Their first story was that Trump didn't test positive until Oct. 1, 2020, two days after he debated Joe Biden. Then Meadows admitted in his new book, The Chief's Chief, that Trump actually tested positive on Sept. 26, three days before the debate. That admission was problematic, since Trump never informed Biden--or hundreds of other unwitting people who interacted closely with the maskless president in the intervening five days--about the test result. So now Trump and Meadows have concocted yet another story: The Sept. 26 result was a "false positive."