2024 : 12 : 4
Shaho Zarei

Shaho Zarei

Academic rank: Assistant Professor
ORCID:
Education: PhD.
ScopusId: 6325
HIndex:
Faculty: Faculty of Science
Address:
Phone: 2492: داخلی

Research

Title
Robust semi-supervised learning via model-based classification
Type
Thesis
Keywords
semi-supervised Classification‎, ‎Model-based classification, ‎Robust estimation, ‎Label and attribute noise, ‎Impartial trimming‎.
Year
2024
Researchers Dashne Eizzaldin Ahmed(Student)، Shaho Zarei(PrimaryAdvisor)

Abstract

‎In a standard classification framework‎, ‎a meticulously selected collection of reliable training data is employed to develop a decision rule designed to reliably classify unlabeled cases within the test set‎. ‎This method has a considerable limitation‎, ‎it requires a substantial quantity of labeled cases to facilitate effective learning‎. ‎Due to the manual nature of labeling‎, ‎the process can be highly laborious and time consuming‎. ‎For this reason‎, ‎semi-supervised approaches have been developed to address these difficulties‎. ‎Within this educational context‎, ‎there exists a limited collection of classified instances for each class‎, ‎alongside a substantial collection of uncategorized instances‎. ‎The goal is to utilize the unlabelled examples in order to enhance the process of learning‎. ‎The existence of unreliable labeled observations‎, ‎including outliers and inaccurately labeled data‎, ‎can severely impair the classifier’s performance‎. ‎This danger is especially significant when the training dataset is somewhat small‎, ‎as it may lack adequate information to mitigate these mistakes‎. ‎The work presented here introduces a robust modification to the model-based classification framework‎, ‎integrating the concepts of impartial trimming and incorporating constraints on the ratio between the maximum and minimum eigenvalues of the group scatter matrices‎. ‎In order to achieve these goals‎, ‎in the First chapter‎, ‎we describe the classification preparations‎, ‎the evaluation of the results‎, ‎and the types of classification methods‎. ‎The Second chapter will include the model-based classification‎, ‎Semi-supervised classification and the concept of attribute and class noise‎, ‎and outliers and its effect on the classification‎. ‎In the Third chapter‎, ‎robust model-based classification for attribute and class noise is discussed in detail and we introduce a new technique called RUPCLASS along with the parameter estimation method with the EM algorithm‎. ‎In the Fourth chapter‎, ‎using several simulations and analysis of heart failure data in Pakistan‎, ‎we put the described methods and algorithms into practical use and evaluation‎. ‎Finally‎, ‎in the Fifth chapter‎, ‎conclusions and future work.