Statistical Learning
The Geometric Occam's Razor Implicit in Deep Learning
Dherin, Benoit, Munn, Michael, Barrett, David G. T.
In over-parameterized deep neural networks there can be many possible parameter configurations that fit the training data exactly. However, the properties of these interpolating solutions are poorly understood. We argue that over-parameterized neural networks trained with stochastic gradient descent are subject to a Geometric Occam's Razor; that is, these networks are implicitly regularized by the geometric model complexity. For one-dimensional regression, the geometric model complexity is simply given by the arc length of the function. For higher-dimensional settings, the geometric model complexity depends on the Dirichlet energy of the function. We explore the relationship between this Geometric Occam's Razor, the Dirichlet energy and other known forms of implicit regularization. Finally, for ResNets trained on CIFAR-10, we observe that Dirichlet energy measurements are consistent with the action of this implicit Geometric Occam's Razor.
Beyond Importance Scores: Interpreting Tabular ML by Visualizing Feature Semantics
Ghorbani, Amirata, Berenbaum, Dina, Ivgi, Maor, Dafna, Yuval, Zou, James
Interpretability is becoming an active research topic as machine learning (ML) models are more widely used to make critical decisions. Tabular data is one of the most commonly used modes of data in diverse applications such as healthcare and finance. Much of the existing interpretability methods used for tabular data only report feature-importance scores -- either locally (per example) or globally (per model) -- but they do not provide interpretation or visualization of how the features interact. We address this limitation by introducing Feature Vectors, a new global interpretability method designed for tabular datasets. In addition to providing feature-importance, Feature Vectors discovers the inherent semantic relationship among features via an intuitive feature visualization technique. Our systematic experiments demonstrate the empirical utility of this new method by applying it to several real-world datasets. We further provide an easy-to-use Python package for Feature Vectors.
A Comprehensive Survey on the Convergence of Vehicular Social Networks and Fog Computing
Miri, Farimasadat, Pazzi, Richard
In recent years, the number of IoT devices has been growing fast which leads to a challenging task for managing, storing, analyzing, and making decisions about raw data from different IoT devices, especially for delay-sensitive applications. In a vehicular network (VANET) environment, the dynamic nature of vehicles makes the current open research issues even more challenging due to the frequent topology changes that can lead to disconnections between vehicles. To this end, a number of research works have been proposed in the context of cloud and fog computing over the 5G infrastructure. On the other hand, there are a variety of research proposals that aim to extend the connection time between vehicles. Vehicular Social Networks (VSNs) have been defined to decrease the burden of connection time between the vehicles. This survey paper first provides the necessary background information and definitions about fog, cloud and related paradigms such as 5G and SDN. Then, it introduces the reader to Vehicular Social Networks, the different metrics and the main differences between VSNs and Online Social Networks. Finally, this survey investigates the related works in the context of VANETs that have demonstrated different architectures to address the different issues in fog computing. Moreover, it provides a categorization of the different approaches and discusses the required metrics in the context of fog and cloud and compares them to Vehicular social networks. A comparison of the relevant related works is discussed along with new research challenges and trends in the domain of VSNs and fog computing.
HRNET: AI on Edge for mask detection and social distancing
Sengupta, Kinshuk, Srivastava, Praveen Ranjan
The purpose of the paper is to provide innovative emerging technology framework for community to combat epidemic situations. The paper proposes a unique outbreak response system framework based on artificial intelligence and edge computing for citizen centric services to help track and trace people eluding safety policies like mask detection and social distancing measure in public or workplace setup. The framework further provides implementation guideline in industrial setup as well for governance and contact tracing tasks. The adoption will thus lead in smart city planning and development focusing on citizen health systems contributing to improved quality of life. The conceptual framework presented is validated through quantitative data analysis via secondary data collection from researcher's public websites, GitHub repositories and renowned journals and further benchmarking were conducted for experimental results in Microsoft Azure cloud environment. The study includes selective AI-models for benchmark analysis and were assessed on performance and accuracy in edge computing environment for large scale societal setup. Overall YOLO model Outperforms in object detection task and is faster enough for mask detection and HRNetV2 outperform semantic segmentation problem applied to solve social distancing task in AI-Edge inferencing environmental setup. The paper proposes new Edge-AI algorithm for building technology-oriented solutions for detecting mask in human movement and social distance. The paper enriches the technological advancement in artificial intelligence and edge-computing applied to problems in society and healthcare systems. The framework further equips government agency, system providers to design and constructs technology-oriented models in community setup to Increase the quality of life using emerging technologies into smart urban environments.
New Datasets for Dynamic Malware Classification
Düzgün, Berkant, Çayır, Aykut, Demirkıran, Ferhat, Kayha, Ceyda Nur, Gençaydın, Buket, Dağ, Hasan
Nowadays, malware and malware incidents are increasing daily, even with various anti-viruses systems and malware detection or classification methodologies. Many static, dynamic, and hybrid techniques have been presented to detect malware and classify them into malware families. Dynamic and hybrid malware classification methods have advantages over static malware classification methods by being highly efficient. Since it is difficult to mask malware behavior while executing than its underlying code in static malware classification, machine learning techniques have been the main focus of the security experts to detect malware and determine their families dynamically. The rapid increase of malware also brings the necessity of recent and updated datasets of malicious software. We introduce two new, updated datasets in this work: One with 9,795 samples obtained and compiled from VirusSamples and the one with 14,616 samples from VirusShare. This paper also analyzes multi-class malware classification performance of the balanced and imbalanced version of these two datasets by using Histogram-based gradient boosting, Random Forest, Support Vector Machine, and XGBoost models with API call-based dynamic malware classification. Results show that Support Vector Machine, achieves the highest score of 94% in the imbalanced VirusSample dataset, whereas the same model has 91% accuracy in the balanced VirusSample dataset. While XGBoost, one of the most common gradient boosting-based models, achieves the highest score of 90% and 80%.in both versions of the VirusShare dataset. This paper also presents the baseline results of VirusShare and VirusSample datasets by using the four most widely known machine learning techniques in dynamic malware classification literature. We believe that these two datasets and baseline results enable researchers in this field to test and validate their methods and approaches.
Panoptic Segmentation Meets Remote Sensing
de Carvalho, Osmar Luiz Ferreira, Júnior, Osmar Abílio de Carvalho, Silva, Cristiano Rosa e, de Albuquerque, Anesmar Olino, Santana, Nickolas Castro, Borges, Dibio Leandro, Gomes, Roberto Arnaldo Trancoso, Guimarães, Renato Fontes
Panoptic segmentation combines instance and semantic predictions, allowing the detection of "things" and "stuff" simultaneously. Effectively approaching panoptic segmentation in remotely sensed data can be auspicious in many challenging problems since it allows continuous mapping and specific target counting. Several difficulties have prevented the growth of this task in remote sensing: (a) most algorithms are designed for traditional images, (b) image labelling must encompass "things" and "stuff" classes, and (c) the annotation format is complex. Thus, aiming to solve and increase the operability of panoptic segmentation in remote sensing, this study has five objectives: (1) create a novel data preparation pipeline for panoptic segmentation, (2) propose an annotation conversion software to generate panoptic annotations; (3) propose a novel dataset on urban areas, (4) modify the Detectron2 for the task, and (5) evaluate difficulties of this task in the urban setting. We used an aerial image with a 0,24-meter spatial resolution considering 14 classes. Our pipeline considers three image inputs, and the proposed software uses point shapefiles for creating samples in the COCO format. Our study generated 3,400 samples with 512x512 pixel dimensions. We used the Panoptic-FPN with two backbones (ResNet-50 and ResNet-101), and the model evaluation considered semantic instance and panoptic metrics. We obtained 93.9, 47.7, and 64.9 for the mean IoU, box AP, and PQ. Our study presents the first effective pipeline for panoptic segmentation and an extensive database for other researchers to use and deal with other data or related problems requiring a thorough scene understanding.
Towards Axiomatic, Hierarchical, and Symbolic Explanation for Deep Models
Ren, Jie, Li, Mingjie, Chen, Qirui, Deng, Huiqi, Zhang, Quanshi
This paper proposes a hierarchical and symbolic And-Or graph (AOG) to objectively explain the internal logic encoded by a well-trained deep model for inference. We first define the objectiveness of an explainer model in game theory, and we develop a rigorous representation of the And-Or logic encoded by the deep model. The objectiveness and trustworthiness of the AOG explainer are both theoretically guaranteed and experimentally verified. Furthermore, we propose several techniques to boost the conciseness of the explanation.
The Essence of Logistic Regression
Logistic Regression aim is to assign a probability to an event occuring or a sample belonging to a certain class given some features. This is analogous to a boolean valued output. An example problem is determining whether a student passes an exam or not. Let's assign a pass (success) as 1 and a fail as 0. Now, let's assume we know how long they have spent studying for their exam, call this X_1, and whether they passed their previous exam, X_2. Where Y is the target, that should take values between 0 and 1, and the β values are the unknown coefficients that we need to compute to fit the model.
Understanding your performance metrics for clustering
Clustering is categorized under unsupervised learning, which forms the niche part of machine learning. Unlike supervised learning which is more common in most common machine learning study, classification tasks learn from the provided labeled data and makes class predictions. However, this does not cause the clustering method to be less desirable, as clustering algorithms are essential in discovering unexplored insights. Thus, it is important to understand the performance of the clustering task and to decide whether the clusters formed are trustable. Silhouette Analysis is the most common method as it is more straightforward compared to others.
Changepoint Analysis of Topic Proportions in Temporal Text Data
Bose, Avinandan, Mukherjee, Soumendu Sundar
Changepoint analysis deals with unsupervised detection and/or estimation of time-points in time-series data, when the distribution generating the data changes. In this article, we consider \emph{offline} changepoint detection in the context of large scale textual data. We build a specialised temporal topic model with provisions for changepoints in the distribution of topic proportions. As full likelihood based inference in this model is computationally intractable, we develop a computationally tractable approximate inference procedure. More specifically, we use sample splitting to estimate topic polytopes first and then apply a likelihood ratio statistic together with a modified version of the wild binary segmentation algorithm of Fryzlewicz et al. (2014). Our methodology facilitates automated detection of structural changes in large corpora without the need of manual processing by domain experts. As changepoints under our model correspond to changes in topic structure, the estimated changepoints are often highly interpretable as marking the surge or decline in popularity of a fashionable topic. We apply our procedure on two large datasets: (i) a corpus of English literature from the period 1800-1922 (Underwoodet al., 2015); (ii) abstracts from the High Energy Physics arXiv repository (Clementet al., 2019). We obtain some historically well-known changepoints and discover some new ones.