Paweena Wanchai

Dr. Paweena Wanchai


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 September 2024 in Journal of Big Data
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IAI Nyoman Mahayasa Adiputra
I Nyoman Mahayasa Adiputra
PWPaweena Wanchai
Paweena Wanchai
Class imbalance is one of many problems of customer churn datasets. One of the common problems is class overlap, where the data have a similar instance between classes. The prediction task of customer churn becomes more challenging when there is class overlap in the data training. In this research, we suggested a hybrid method based on tabular GANs, called CTGAN-ENN, to address class overlap and imbalanced data in datasets of customers that churn. We used five different customer churn datasets from an open platform. CTGAN is a tabular GAN-based oversampling to address class imbalance but has a class overlap problem. We combined CTGAN with the ENN under-sampling technique to overcome the class overlap. CTGAN-ENN reduced the number of class overlaps by each feature in all datasets. We investigated how effective CTGAN-ENN is in each machine learning technique. Based on our experiments, CTGAN-ENN achieved satisfactory results in KNN, GBM, XGB and LGB machine learning performance for customer churn predictions. We compared CTGAN-ENN with common over-sampling and hybrid sampling methods, and CTGAN-ENN achieved outperform results compared with other sampling methods and algorithm-level methods with cost-sensitive learning in several machine learning algorithms. We provide a time consumption algorithm between CTGAN and CTGAN-ENN. CTGAN-ENN achieved less time consumption than CTGAN. Our research work provides a new framework to handle customer churn prediction problems with several types of imbalanced datasets and can be useful in real-world data from customer churn prediction.

11 February 2025 in Electronics
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IAI Nyoman Mahayasa Adiputra
I Nyoman Mahayasa Adiputra
Pei-Chun LinPei-Chun Lin
Pei-Chun Lin
PWPaweena Wanchai
Paweena Wanchai
Credit score models are essential tools for evaluating creditworthiness and mitigating financial risks. However, the imbalanced nature of multi-class credit score datasets poses significant challenges for traditional classification algorithms, leading to poor performance in minority classes. This study explores the effectiveness of Generative Adversarial Network (GAN)-based oversampling methods, including CTGAN, CopulaGAN, WGAN-GP, and DraGAN, in addressing this issue. By synthesizing realistic data for minority classes and integrating it with majority class data, the study benchmarks these GAN-based methods across classical (KNN, Decision Tree, Logistic Regression) and ensemble machine learning models (XGBoost, Random Forest, LightGBM). Evaluation metrics such as accuracy and F1-score reveal that WGAN-GP consistently achieves superior performance, especially when combined with Random Forest, outperforming other methods in balancing dataset representation and enhancing classification accuracy. The results showed that WGAN-GP + RF achieved 0.873 in accuracy, 0.936 F1-score in the “good” class, 0.806 F1-score in the “poor” class, and 0.816 F1-score in the “standard” class. The findings underscore the potential of GAN-based oversampling in improving multi-class credit score classification and highlight future directions, including hybrid sampling and cost-sensitive learning, to address remaining challenges.

1 January 2017 in Journal of Healthcare Engineering
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NANgamnij Arch-Int
Ngamnij Arch-Int
SASomjit Arch-Int
Somjit Arch-Int
SSSuphachoke Sonsilphong
Suphachoke Sonsilphong
PWPaweena Wanchai
Paweena Wanchai
Within the numerous and heterogeneous web services offered through different sources, automatic web services composition is the most convenient method for building complex business processes that permit invocation of multiple existing atomic services. The current solutions in functional web services composition lack autonomous queries of semantic matches within the parameters of web services, which are necessary in the composition of large-scale related services. In this paper, we propose a graph-based Semantic Web Services composition system consisting of two subsystems: management time and run time. The management-time subsystem is responsible for dependency graph preparation in which a dependency graph of related services is generated automatically according to the proposed semantic matchmaking rules. The run-time subsystem is responsible for discovering the potential web services and nonredundant web services composition of a user’s query using a graph-based searching algorithm. The proposed approach was applied to healthcare data integration in different health organizations and was evaluated according to two aspects: execution time measurement and correctness measurement.

19 June 2025 in PeerJ Computer Science
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IAI Nyoman Mahayasa Adiputra
I Nyoman Mahayasa Adiputra
PWPaweena Wanchai
Paweena Wanchai
Pei-Chun LinPei-Chun Lin
Pei-Chun Lin
Background: Imbalanced and overlapped data in customer churn prediction significantly impact classification results. Various sampling and hybrid sampling methods have demonstrated effectiveness in addressing these issues. However, these methods have not performed well with classical machine learning algorithms. Methods: To optimize the performance of classical machine learning on customer churn prediction tasks, this study introduces an extension framework called CostLearnGAN, a tabular generative adversarial network (GAN)-hybrid sampling method, and cost-sensitive Learning. Utilizing a cost-sensitive learning perspective, this research aims to enhance the performance of several classical machine learning algorithms in customer churn prediction tasks. Based on the experimental results classical machine learning algorithms exhibit shorter execution times, making them suitable for predicting churn in large customer bases. Results: This study conducted an experiment with six comparative sampling methods, six datasets, and three machine learning algorithms. The results show that CostLearnGAN achieved a satisfying result across all evaluation metrics with a 1.44 average mean rank score. Additionally, this study provided a robustness measurement for algorithms, demonstrating that CostLearnGAN outperforms other sampling methods in improving the performance of classical machine learning models with a 5.68 robustness value on average.

1 January 2019 in Communications of the Association for Information Systems
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PWPaweena Wanchai
Paweena Wanchai
AAAntonio Díaz Andrade
Antonio Díaz Andrade
ATAngsana Techatassanasoontorn
Angsana Techatassanasoontorn
The introduction of enterprise-wide systems requires users to simultaneously adjust to both the new system’s requirements and changes associated with modified business processes—an adaptation that often goes beyond conspicuous behavioral elements. Therefore, to investigate the underlying attributes that characterize user interaction with and adaptation to information technology (IT), we collected data from four organizations that had implemented enterprise-wide systems for at least three years prior to commencing fieldwork. By taking a grounded theory approach, we identify four distinct adaptation patterns: reluctant, compliant, faithful, and enthusiastic. These patterns represent configurations of five interrelated attributes that users espouse in their interaction with enterprise-wide systems: attitude towards the system, approach to learning how to use the system, level of interaction with the system, exploration of system features, and stance towards changing work practices. We propose an emergent, substantive theory of IT adaptation patterns that explains the intricate interplay of individual, task, and organizational initiatives in shaping these adaptation patterns.