Clustering
Incomplete Multi-view Clustering via Cross-view Relation Transfer
Wang, Yiming, Chang, Dongxia, Fu, Zhiqiang, Zhao, Yao
In this paper, we consider the problem of multi-view clustering on incomplete views. Compared with complete multi-view clustering, the view-missing problem increases the difficulty of learning common representations from different views. To address the challenge, we propose a novel incomplete multi-view clustering framework, which incorporates cross-view relation transfer and multi-view fusion learning. Specifically, based on the consistency existing in multi-view data, we devise a cross-view relation transfer-based completion module, which transfers known similar inter-instance relationships to the missing view and recovers the missing data via graph networks based on the transferred relationship graph. Then the view-specific encoders are designed to extract the recovered multi-view data, and an attention-based fusion layer is introduced to obtain the common representation. Moreover, to reduce the impact of the error caused by the inconsistency between views and obtain a better clustering structure, a joint clustering layer is introduced to optimize recovery and clustering simultaneously. Extensive experiments conducted on several real datasets demonstrate the effectiveness of the proposed method.
Outlier Detection using AI: A Survey
Sikder, Md Nazmul Kabir, Batarseh, Feras A.
An outlier is an event or observation that is defined as an unusual activity, intrusion, or a suspicious data point that lies at an irregular distance from a population. The definition of an outlier event, however, is subjective and depends on the application and the domain (Energy, Health, Wireless Network, etc.). It is important to detect outlier events as carefully as possible to avoid infrastructure failures because anomalous events can cause minor to severe damage to infrastructure. For instance, an attack on a cyber-physical system such as a microgrid may initiate voltage or frequency instability, thereby damaging a smart inverter which involves very expensive repairing. Unusual activities in microgrids can be mechanical faults, behavior changes in the system, human or instrument errors or a malicious attack. Accordingly, and due to its variability, Outlier Detection (OD) is an ever-growing research field. In this chapter, we discuss the progress of OD methods using AI techniques. For that, the fundamental concepts of each OD model are introduced via multiple categories. Broad range of OD methods are categorized into six major categories: Statistical-based, Distance-based, Density-based, Clustering-based, Learning-based, and Ensemble methods. For every category, we discuss recent state-of-the-art approaches, their application areas, and performances. After that, a brief discussion regarding the advantages, disadvantages, and challenges of each technique is provided with recommendations on future research directions. This survey aims to guide the reader to better understand recent progress of OD methods for the assurance of AI.
Fast Topological Clustering with Wasserstein Distance
Songdechakraiwut, Tananun, Krause, Bryan M., Banks, Matthew I., Nourski, Kirill V., Van Veen, Barry D.
The topological patterns exhibited by many real-world networks motivate the development of topology-based methods for assessing the similarity of networks. However, extracting topological structure is difficult, especially for large and dense networks whose node degrees range over multiple orders of magnitude. In this paper, we propose a novel and computationally practical topological clustering method that clusters complex networks with intricate topology using principled theory from persistent homology and optimal transport. Such networks are aggregated into clusters through a centroid-based clustering strategy based on both their topological and geometric structure, preserving correspondence between nodes in different networks. The notions of topological proximity and centroid are characterized using a novel and efficient approach to computation of the Wasserstein distance and barycenter for persistence barcodes associated with connected components and cycles. The proposed method is demonstrated to be effective using both simulated networks and measured functional brain networks.
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.
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.
Transformed K-means Clustering
Goel, Anurag, Majumdar, Angshul
In this work we propose a clustering framework based on the paradigm of transform learning. In simple terms the representation from transform learning is used for K-means clustering; however, the problem is not solved in such a na\"ive piecemeal fashion. The K-means clustering loss is embedded into the transform learning framework and the joint problem is solved using the alternating direction method of multipliers. Results on document clustering show that our proposed approach improves over the state-of-the-art.
Natural Language Processing in-and-for Design Research
Siddharth, L, Blessing, Lucienne T. M., Luo, Jianxi
We review the scholarly contributions that utilise Natural Language Processing (NLP) methods to support the design process. Using a heuristic approach, we collected 223 articles published in 32 journals and within the period 1991-present. We present state-of-the-art NLP in-and-for design research by reviewing these articles according to the type of natural language text sources: internal reports, design concepts, discourse transcripts, technical publications, consumer opinions, and others. Upon summarizing and identifying the gaps in these contributions, we utilise an existing design innovation framework to identify the applications that are currently being supported by NLP. We then propose a few methodological and theoretical directions for future NLP in-and-for design research.
A Note on Machine Learning
Unsupervised learning uses algorithms to analyze and cluster unlabeled datasets. These algorithms discover hidden patterns and data groupings without the need of human intenvention. Generally it's used for expolarity data analysis, customer segmentation, recommender systems, big data visualization, feature elicitation etc. Roughly, there are three types of unsupervised learning approach. Clustering is a data mining techinuqe which groups unlabeled data based on similarities and differences. Clustering algorithms are used to process raw, unclassified data objects into groups represented by structures and patterns in the information.
Learn How To Do K-Means Clustering On An Image
If you've ever read anything related to data science, machine learning or data mining, there is a high probability of you coming across clustering. Clustering is a process of classifying data in clusters based on how similar the data is. There are many clustering algorithms. One of the most known is the K-means algorithm. K-means clusters the data into a determined number of clusters.
Introduction to Components with Knime Analytics - Analytics Vidhya
This article was published as a part of the Data Science Blogathon. In the last article A Friendly Introduction to KNIME Analytics Platform I provided a brief insight into the open-source software KNIME Analytics Platform and what it is capable of. With the help of a customer segmentation example, I showed the general functions of KNIME Analytics Platform. This article takes up a topic that was briefly mentioned at the end of the last article: Components. I'll provide an in-depth explanation of what components are, what functionalities they have, and why they are useful.