scholarly journals Embedding-Based Complex Feature Value Coupling Learning for Detecting Outliers in Non-IID Categorical Data

2019 ◽  
Vol 33 ◽  
pp. 5541-5548 ◽  
Author(s):  
Hongzuo Xu ◽  
Yongjun Wang ◽  
Zhiyue Wu ◽  
Yijie Wang
Keyword(s):  
Outlier Detection ◽  
Categorical Data ◽  
State Of The Art ◽  
High Order ◽  
Detection Methods ◽  
Order Complex ◽  
Value Network ◽  
Learning Framework ◽  
A Value ◽  
Real World Datasets

Non-IID categorical data is ubiquitous and common in realworld applications. Learning various kinds of couplings has been proved to be a reliable measure when detecting outliers in such non-IID data. However, it is a critical yet challenging problem to model, represent, and utilise high-order complex value couplings. Existing outlier detection methods normally only focus on pairwise primary value couplings and fail to uncover real relations that hide in complex couplings, resulting in suboptimal and unstable performance. This paper introduces a novel unsupervised embedding-based complex value coupling learning framework EMAC and its instance SCAN to address these issues. SCAN first models primary value couplings. Then, coupling bias is defined to capture complex value couplings with different granularities and highlight the essence of outliers. An embedding method is performed on the value network constructed via biased value couplings, which further learns high-order complex value couplings and embeds these couplings into a value representation matrix. Bidirectional selective value coupling learning is proposed to show how to estimate value and object outlierness through value couplings. Substantial experiments show that SCAN (i) significantly outperforms five state-of-the-art outlier detection methods on thirteen real-world datasets; and (ii) has much better resilience to noise than its competitors.

scholarly journals MLRDA: A Multi-Task Semi-Supervised Learning Framework for Drug-Drug Interaction Prediction

2019 ◽  
Author(s):  
Xu Chu ◽  
Yang Lin ◽  
Yasha Wang ◽  
Leye Wang ◽  
Jiangtao Wang ◽  
...  
Keyword(s):  
Supervised Learning ◽  
State Of The Art ◽  
Multiple Drug ◽  
Prediction Methods ◽  
Learning Models ◽  
Preventable Hospitalizations ◽  
Interaction Prediction ◽  
Learning Framework ◽  
Task Learning ◽  
Real World Datasets

Drug-drug interactions (DDIs) are a major cause of preventable hospitalizations and deaths. Recently, researchers in the AI community try to improve DDI prediction in two directions, incorporating multiple drug features to better model the pharmacodynamics and adopting multi-task learning to exploit associations among DDI types. However, these two directions are challenging to reconcile due to the sparse nature of the DDI labels which inflates the risk of overfitting of multi-task learning models when incorporating multiple drug features. In this paper, we propose a multi-task semi-supervised learning framework MLRDA for DDI prediction. MLRDA effectively exploits information that is beneficial for DDI prediction in unlabeled drug data by leveraging a novel unsupervised disentangling loss CuXCov. The CuXCov loss cooperates with the classification loss to disentangle the DDI prediction relevant part from the irrelevant part in a representation learnt by an autoencoder, which helps to ease the difficulty in mining useful information for DDI prediction in both labeled and unlabeled drug data. Moreover, MLRDA adopts a multi-task learning framework to exploit associations among DDI types. Experimental results on real-world datasets demonstrate that MLRDA significantly outperforms state-of-the-art DDI prediction methods by up to 10.3% in AUPR.

scholarly journals Image-Based Malware Classification Using VGG19 Network and Spatial Convolutional Attention

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2444
Author(s):  
Mazhar Javed Awan ◽  
Osama Ahmed Masood ◽  
Mazin Abed Mohammed ◽  
Awais Yasin ◽  
Azlan Mohd Zain ◽  
...  
Keyword(s):  
High Performance ◽  
State Of The Art ◽  
Malware Detection ◽  
Detection Methods ◽  
Learning Framework ◽  
Malware Classification ◽  
Proposed Model ◽  
Communication Devices ◽  
Digital Assets

In recent years the amount of malware spreading through the internet and infecting computers and other communication devices has tremendously increased. To date, countless techniques and methodologies have been proposed to detect and neutralize these malicious agents. However, as new and automated malware generation techniques emerge, a lot of malware continues to be produced, which can bypass some state-of-the-art malware detection methods. Therefore, there is a need for the classification and detection of these adversarial agents that can compromise the security of people, organizations, and countless other forms of digital assets. In this paper, we propose a spatial attention and convolutional neural network (SACNN) based on deep learning framework for image-based classification of 25 well-known malware families with and without class balancing. Performance was evaluated on the Malimg benchmark dataset using precision, recall, specificity, precision, and F1 score on which our proposed model with class balancing reached 97.42%, 97.95%, 97.33%, 97.11%, and 97.32%. We also conducted experiments on SACNN with class balancing on benign class, also produced above 97%. The results indicate that our proposed model can be used for image-based malware detection with high performance, despite being simpler as compared to other available solutions.

SAND

2021 ◽  
Vol 14 (10) ◽  
pp. 1717-1729
Author(s):  
Paul Boniol ◽  
John Paparrizos ◽  
Themis Palpanas ◽  
Michael J. Franklin
Keyword(s):  
Anomaly Detection ◽  
Domain Knowledge ◽  
State Of The Art ◽  
Data Distribution ◽  
Detection Methods ◽  
Current State ◽  
Normal Behavior ◽  
Real World Datasets ◽  
Increasing Demand ◽  
Entire Dataset

With the increasing demand for real-time analytics and decision making, anomaly detection methods need to operate over streams of values and handle drifts in data distribution. Unfortunately, existing approaches have severe limitations: they either require prior domain knowledge or become cumbersome and expensive to use in situations with recurrent anomalies of the same type. In addition, subsequence anomaly detection methods usually require access to the entire dataset and are not able to learn and detect anomalies in streaming settings. To address these problems, we propose SAND, a novel online method suitable for domain-agnostic anomaly detection. SAND aims to detect anomalies based on their distance to a model that represents normal behavior. SAND relies on a novel steaming methodology to incrementally update such model, which adapts to distribution drifts and omits obsolete data. The experimental results on several real-world datasets demonstrate that SAND correctly identifies single and recurrent anomalies without prior knowledge of the characteristics of these anomalies. SAND outperforms by a large margin the current state-of-the-art algorithms in terms of accuracy while achieving orders of magnitude speedups.

scholarly journals Selective oversampling approach for strongly imbalanced data

2021 ◽  
Vol 7 ◽  
pp. e604
Author(s):  
Peter Gnip ◽  
Liberios Vokorokos ◽  
Peter Drotár
Keyword(s):  
Outlier Detection ◽  
Real World ◽  
State Of The Art ◽  
Imbalanced Data ◽  
Prediction Performance ◽  
Classifier Performance ◽  
Real World Applications ◽  
Real World Datasets ◽  
Synthetic Datasets ◽  
Representative Samples

Challenges posed by imbalanced data are encountered in many real-world applications. One of the possible approaches to improve the classifier performance on imbalanced data is oversampling. In this paper, we propose the new selective oversampling approach (SOA) that first isolates the most representative samples from minority classes by using an outlier detection technique and then utilizes these samples for synthetic oversampling. We show that the proposed approach improves the performance of two state-of-the-art oversampling methods, namely, the synthetic minority oversampling technique and adaptive synthetic sampling. The prediction performance is evaluated on four synthetic datasets and four real-world datasets, and the proposed SOA methods always achieved the same or better performance than other considered existing oversampling methods.

scholarly journals Earthquake Damage Region Detection by Multitemporal Coherence Map Analysis of Radar and Multispectral Imagery

2021 ◽  
Vol 13 (6) ◽  
pp. 1195
Author(s):  
Mahdi Hasanlou ◽  
Reza Shah-Hosseini ◽  
Seyd Teymoor Seydi ◽  
Sadra Karimzadeh ◽  
Masashi Matsuoka
Keyword(s):  
Damage Detection ◽  
State Of The Art ◽  
Low Cost ◽  
Detection Methods ◽  
Atmospheric Conditions ◽  
Region Detection ◽  
Learning Framework ◽  
Radar Images ◽  
Measure Analysis ◽  
Map Analysis

Earth, as humans’ habitat, is constantly affected by natural events, such as floods, earthquakes, thunder, and drought among which earthquakes are considered one of the deadliest and most catastrophic natural disasters. The Iran-Iraq earthquake occurred in Kermanshah Province, Iran in November 2017. It was a 7.4-magnitude seismic event that caused immense damages and loss of life. The rapid detection of damages caused by earthquakes is of great importance for disaster management. Thanks to their wide coverage, high resolution, and low cost, remote-sensing images play an important role in environmental monitoring. This study presents a new damage detection method at the unsupervised level, using multitemporal optical and radar images acquired through Sentinel imagery. The proposed method is applied in two main phases: (1) automatic built-up extraction using spectral indices and active learning framework on Sentinel-2 imagery; (2) damage detection based on the multitemporal coherence map clustering and similarity measure analysis using Sentinel-1 imagery. The main advantage of the proposed method is that it is an unsupervised method with simple usage, a low computing burden, and using medium spatial resolution imagery that has good temporal resolution and is operative at any time and in any atmospheric conditions, with high accuracy for detecting deformations in buildings. The accuracy analysis of the proposed method found it visually and numerically comparable to other state-of-the-art methods for built-up area detection. The proposed method is capable of detecting built-up areas with an accuracy of more than 96% and a kappa of about 0.89 in overall comparison to other methods. Furthermore, the proposed method is also able to detect damaged regions compared to other state-of-the-art damage detection methods with an accuracy of more than 70%.

scholarly journals Unsupervised Feature Selection for Outlier Detection on Streaming Data to Enhance Network Security

2021 ◽  
Vol 11 (24) ◽  
pp. 12073
Author(s):  
Michael Heigl ◽  
Enrico Weigelt ◽  
Dalibor Fiala ◽  
Martin Schramm
Keyword(s):  
Feature Selection ◽  
Outlier Detection ◽  
Data Streams ◽  
State Of The Art ◽  
Streaming Data ◽  
Detection Methods ◽  
Unsupervised Feature Selection ◽  
Detection Algorithms ◽  
Efficient Detection ◽  
Selection For

Over the past couple of years, machine learning methods—especially the outlier detection ones—have anchored in the cybersecurity field to detect network-based anomalies rooted in novel attack patterns. However, the ubiquity of massive continuously generated data streams poses an enormous challenge to efficient detection schemes and demands fast, memory-constrained online algorithms that are capable to deal with concept drifts. Feature selection plays an important role when it comes to improve outlier detection in terms of identifying noisy data that contain irrelevant or redundant features. State-of-the-art work either focuses on unsupervised feature selection for data streams or (offline) outlier detection. Substantial requirements to combine both fields are derived and compared with existing approaches. The comprehensive review reveals a research gap in unsupervised feature selection for the improvement of outlier detection methods in data streams. Thus, a novel algorithm for Unsupervised Feature Selection for Streaming Outlier Detection, denoted as UFSSOD, will be proposed, which is able to perform unsupervised feature selection for the purpose of outlier detection on streaming data. Furthermore, it is able to determine the amount of top-performing features by clustering their score values. A generic concept that shows two application scenarios of UFSSOD in conjunction with off-the-shell online outlier detection algorithms has been derived. Extensive experiments have shown that a promising feature selection mechanism for streaming data is not applicable in the field of outlier detection. Moreover, UFSSOD, as an online capable algorithm, yields comparable results to a state-of-the-art offline method trimmed for outlier detection.

scholarly journals Improving Sequential Recommendation Consistency with Self-Supervised Imitation

2021 ◽  
Author(s):  
Xu Yuan ◽  
Hongshen Chen ◽  
Yonghao Song ◽  
Xiaofang Zhao ◽  
Zhuoye Ding
Keyword(s):  
State Of The Art ◽  
User Interaction ◽  
Global Perspective ◽  
Sparse Learning ◽  
Temporal Consistency ◽  
Chronological Order ◽  
Learning Framework ◽  
Real World Datasets ◽  
Interaction History ◽  
Global And Local

Most sequential recommendation models capture the features of consecutive items in a user-item interaction history. Though effective, their representation expressiveness is still hindered by the sparse learning signals. As a result, the sequential recommender is prone to make inconsistent predictions. In this paper, we propose a model, SSI, to improve sequential recommendation consistency with Self-Supervised Imitation. Precisely, we extract the consistency knowledge by utilizing three self-supervised pre-training tasks, where temporal consistency and persona consistency capture user-interaction dynamics in terms of the chronological order and persona sensitivities, respectively. Furthermore, to provide the model with a global perspective, global session consistency is introduced by maximizing the mutual information among global and local interaction sequences. Finally, to comprehensively take advantage of all three independent aspects of consistency-enhanced knowledge, we establish an integrated imitation learning framework. The consistency knowledge is effectively internalized and transferred to the student model by imitating the conventional prediction logit as well as the consistency-enhanced item representations. In addition, the flexible self-supervised imitation framework can also benefit other student recommenders. Experiments on four real-world datasets show that SSI effectively outperforms the state-of-the-art sequential recommendation methods.

scholarly journals sDeepFM: Multi-Scale Stacking Feature Interactions for Click-Through Rate Prediction

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 350
Author(s):  
Baohua Qiang ◽  
Yongquan Lu ◽  
Minghao Yang ◽  
Xianjun Chen ◽  
Jinlong Chen ◽  
...  
Keyword(s):  
State Of The Art ◽  
Receptive Fields ◽  
Area Under The Curve ◽  
Sparse Data ◽  
High Order ◽  
Multi Scale ◽  
Feature Interactions ◽  
Novel Structure ◽  
Real World Datasets ◽  
Click Through Rate

For estimating the click-through rate of advertisements, there are some problems in that the features cannot be automatically constructed, or the features built are relatively simple, or the high-order combination features are difficult to learn under sparse data. To solve these problems, we propose a novel structure multi-scale stacking pooling (MSSP) to construct multi-scale features based on different receptive fields. The structure stacks multi-scale features bi-directionally from the angles of depth and width by constructing multiple observers with different angles and different fields of view, ensuring the diversity of extracted features. Furthermore, by learning the parameters through factorization, the structure can ensure high-order features being effectively learned in sparse data. We further combine the MSSP with the classical deep neural network (DNN) to form a unified model named sDeepFM. Experimental results on two real-world datasets show that the sDeepFM outperforms state-of-the-art models with respect to area under the curve (AUC) and log loss.

scholarly journals On the Improvement of the Isolation Forest Algorithm for Outlier Detection with Streaming Data

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1534
Author(s):  
Michael Heigl ◽  
Kumar Ashutosh Anand ◽  
Andreas Urmann ◽  
Dalibor Fiala ◽  
Martin Schramm ◽  
...  
Keyword(s):  
Outlier Detection ◽  
Real World ◽  
High Speed ◽  
State Of The Art ◽  
High Volume ◽  
Streaming Data ◽  
Steady Increase ◽  
Efficient Detection ◽  
Real World Datasets ◽  
Isolation Forest

In recent years, detecting anomalies in real-world computer networks has become a more and more challenging task due to the steady increase of high-volume, high-speed and high-dimensional streaming data, for which ground truth information is not available. Efficient detection schemes applied on networked embedded devices need to be fast and memory-constrained, and must be capable of dealing with concept drifts when they occur. Different approaches for unsupervised online outlier detection have been designed to deal with these circumstances in order to reliably detect malicious activity. In this paper, we introduce a novel framework called PCB-iForest, which generalized, is able to incorporate any ensemble-based online OD method to function on streaming data. Carefully engineered requirements are compared to the most popular state-of-the-art online methods with an in-depth focus on variants based on the widely accepted isolation forest algorithm, thereby highlighting the lack of a flexible and efficient solution which is satisfied by PCB-iForest. Therefore, we integrate two variants into PCB-iForest—an isolation forest improvement called extended isolation forest and a classic isolation forest variant equipped with the functionality to score features according to their contributions to a sample’s anomalousness. Extensive experiments were performed on 23 different multi-disciplinary and security-related real-world datasets in order to comprehensively evaluate the performance of our implementation compared with off-the-shelf methods. The discussion of results, including AUC, F1 score and averaged execution time metric, shows that PCB-iForest clearly outperformed the state-of-the-art competitors in 61% of cases and even achieved more promising results in terms of the tradeoff between classification and computational costs.

Sign in / Sign up

Export Citation Format

Share Document