National Taiwan University of Science and Technology

About: National Taiwan University of Science and Technology is a education organization based out in Taipei, Taipei, Taiwan. It is known for research contribution in the topics: Fuzzy logic & Control theory. The organization has 16288 authors who have published 21577 publications receiving 426294 citations. The organization is also known as: Taiwan Tech & Taiwantech.

Anomaly Detection via Online Oversampling Principal Component Analysis

Abstract: Anomaly detection has been an important research topic in data mining and machine learning. Many real-world applications such as intrusion or credit card fraud detection require an effective and efficient framework to identify deviated data instances. However, most anomaly detection methods are typically implemented in batch mode, and thus cannot be easily extended to large-scale problems without sacrificing computation and memory requirements. In this paper, we propose an online oversampling principal component analysis (osPCA) algorithm to address this problem, and we aim at detecting the presence of outliers from a large amount of data via an online updating technique. Unlike prior principal component analysis (PCA)-based approaches, we do not store the entire data matrix or covariance matrix, and thus our approach is especially of interest in online or large-scale problems. By oversampling the target instance and extracting the principal direction of the data, the proposed osPCA allows us to determine the anomaly of the target instance according to the variation of the resulting dominant eigenvector. Since our osPCA need not perform eigen analysis explicitly, the proposed framework is favored for online applications which have computation or memory limitations. Compared with the well-known power method for PCA and other popular anomaly detection algorithms, our experimental results verify the feasibility of our proposed method in terms of both accuracy and efficiency.

Brand image strategy affects brand equity after M&A

Abstract: Purpose – The purpose of this study is to examine the relationship between the variance of two brand images and dimensions of brand equity after M&A, especially when the acquirer‐dominant is affiliated to a weak brand image and the acquired one has a stronger brand imageDesign/methodology/approach – In total, 409 responses were collected through random sampling from an internet survey platform in Taiwan (weak image differences were gathered from 209 respondents and strong image differences were gathered from 200 respondents)Findings – This study uses an experimental design to discuss how the variance of two brand images (this study uses two kinds of M&A: a company with an inferior brand image acquires one with a superior or average brand image) affects the acquirer's brand equity (perceived quality, brand association, and brand loyalty) This study also examines how brand equity of an acquired brand changes after M&A Results from the MANOVA and paired‐sample t‐test methods show that the greater the per