2016-07-06 to 2021-02-16 | Doctor of Mathematics/Ph.D (Doctor of Mathematics), Institut Teknologi Bnadung, Indonesia
2011-07-09 to 2013-07-09 | Master of Education/M.Pd (Mathematics Education), Universitas Pendidikan Indonesia, Indonesia
2007-07-04 to 2011-07-07 | Bachelor of Mathematics Education/S.Pd. (Mathematics Education), Universitas Pendidikan Indonesia, Indonesia
RESEARCH INTERESTS
Mathematics Education
Education Statistics
Education Research Methodology
Correspondence Analysis
Categorical Data
24
Scopus Publications
6719
Scholar Citations
17
Scholar h-index
28
Scholar i10-index
Scopus Publications
Tucker3 Tensor Decomposition for the Standardized Residual Hypermatrix on Three-Way Correspondence Analysis Karunia Eka Lestari, Mokhammad Ridwan Yudhanegara, Edwin Setiawan Nugraha, Sisilia Sylviani Journal of the Indonesian Mathematical Society, 2025 This study investigates the theoretical and practical mathematical aspects of Tucker3 tensor decomposition from the three-way correspondence analysis point of view. Since the standardized residual hypermatrix represents the association of the three categorical variables, this study focused on (1) Tucker3 tensor decomposition for the standardized residual hypermatrix, (2) some mathematical properties of Tucker3 tensor decomposition, and (3) constructing the correspondence plot via Tucker3 tensor decomposition. Some mathematical results are presented in lemmas, theorems and algorithms, while a practical result is exhibited at the end of the discussion.
ESTIMATION OF VALUE AT RISK FOR GENERAL INSURANCE COMPANY STOCKS USING THE GARCH MODEL Edwin Setiawan Nugraha, Agna Olivia, Fauziah Nur Fahirah Sudding, Karunia Eka Lestari Barekeng, 2025 Investment plays a crucial role in supporting economic development by allocating funds to generate future profits. Among various investment options, stock investment is widely popular. However, investors face the challenge of developing strategies to maximize returns while minimizing risks. Effective investment requires understanding the potential maximum risk of loss, known as Value at Risk (VaR). This research focuses on estimating VaR for four top general insurance companies in Indonesia: PT Lippo General Insurance Tbk (LPGI), PT Asuransi Tugu Pratama Indonesia Tbk (TUGU), PT Victoria Insurance Tbk (VINS), and PT Asuransi Dayin Mitra Tbk (ASDM). These companies were selected due to their leading positions in the industry. The Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model, an extension of the ARIMA method designed to handle volatility clustering, is utilized for VaR estimation. Results at confidence levels of 90%, 95%, and 99% reveal that VINS carries the highest risk, with a maximum VaR of IDR 2,848,710 at 99% confidence, while LPGI shows the lowest risk, with a maximum VaR of IDR 22,677. For TUGU, the maximum possible loss is IDR 517,589, and for ASDM, it is IDR 1,532,267. Backtesting confirms the reliability of the models, with some accepted at specific significance levels. Based on this analysis, the results can help investors make investment decisions that minimize potential losses, specifically in the four stocks analyzed.
CLUSTERING BASED ON BETWEENNESS CENTRALITY IN PERIOD: TRANSFORMATION OF CORRELATION COEFFICIENT VALUE INTO DISTANCE IN MATRIC SPACE Mokhammad Ridwan Yudhanegara, Edwin Setiawan Nugraha, Sisilia Sylviani, Karunia Eka Lestari, Ebenezer Bonyah Barekeng, 2025 The main information of this research is the transformation of the correlation coefficient value for stock price into the distance. It is done to create a representation in metric space that can be used in cluster analysis on the correlation network, which is a dynamic network. The dynamic network is generated from the weighted edges in the form of distances in each period. Finding the cluster members of the network can be analyzed using a simple technique called a minimum spanning tree. The central cluster member is the vertex betweenness. Vertex betweenness represents banking companies with a high degree of proximity and correlation. It means that the banks that are members of the central cluster are banks with high investment value. Clustering based on betweenness centrality in the case study of stock price correlation becomes useful when transforming the value of the correlation coefficient to distance. The effort to build a network with the edge weight being the distance makes the minimum spanning tree a simple, valuable method for cluster analysis on bank stock prices. In particular, the benefit to investors, i.e., it can reveal which assets are closely correlated, indicating that they may respond to market events in a similar way and make decisions in stock purchases
Clustering Company Profitability from the IDX30 Index Using K-Medoids and DBSCAN Edwin Setiawan Nugraha, Andreanne Intan Sulistyo Wardhani, Karunia Eka Lestari Icoait 2025 1st International Conference on Artificial Intelligence Technology Artificial Intelligence Driving Prosperity and Sustainability in the Modern World, 2025 The capital market serves as an intermediary for investors and companies seeking capital. In the Indonesian capital market, the IDX30 is a stock price index consisting of 30 highly liquid companies that reflect market performance in Indonesia. An important factor that needs to be evaluated before considering investing is the company's profitability ratio, which reflects the company's ability to generate profits. This research seeks to find patterns in the profitability ratios of IDX30 companies through the application of clustering techniques, specifically by using K-Medoids and Density-Based Spatial Clustering of Applications with Noise (DBSCAN) approaches. The exploited data are secondary data collected from the companies' annual reports for the period 2023, including Return on Assets (ROA), Return on Equity (ROE), Net Profit Margin (NPM), and Gross Profit Margin (GPM). Clustering analysis resulted in four clusters using K-Medoids and three clusters using DBSCAN. The results of the analysis show that the companies categorized in cluster 0 and 3 KMedoids and cluster 0 DBSCAN exhibit well-balanced profitability ratios, signifying their reliable ability to generate profits for investors. Simultaneously, DBSCAN effectively detects outlier companies that require more attention in investment considerations. Both approaches effectively identify data patterns based on their attributes, with DBSCAN having higher sensitivity to outliers. The findings of this study offer valuable insights for investors in identifying profitable companies and enhance the use of clustering algorithms in financial data analysis.
NEUROCOGNITIVE PREDICTION OF DYSLEXIC HANDWRITING PATTERN USING AN EXPLAINABLE AI-DRIVEN CUSTOM LITEBINARYNET-CNN Karunia Eka Lestari, Sri Winarni, Aditya Prihandhika, Edwin Setiawan Nugraha, Mokhammad Ridwan Yudhanegara Communications in Mathematical Biology and Neuroscience, 2025 Artificial intelligence (AI) based on deep learning, particularly convolutional neural networks (CNNs), shows strong potential in handwriting recognition. However, their limited transparency constrains use in sensitive domains such as dyslexia prediction. From a neurocognitive standpoint, dyslexia stems from atypical neural processing reflected in handwriting irregularities, making handwriting prediction a neurocognitive inference task. This study introduces a neurocognitively informed framework, Custom LiteBinaryNet, a lightweight CNN integrated with Explainable AI (XAI) for transparent dyslexia prediction from handwriting. Custom LiteBinaryNet-CNN was evaluated in baseline and tuned configurations, the latter optimized through aggressive augmentation and hyperparameter tuning. Compared to LeNet-5 (60.49% accuracy, AUC 0.56), the baseline achieved 78.73% accuracy and AUC 0.87, while the tuned model reached 83.36% accuracy and AUC 0.91. Loss analysis confirmed improved stability and generalization. XAI methods, including Grad-CAM and Occlusion Sensitivity, revealed neurocognitive interpretability by highlighting handwriting traits, such as letter reversals and spatial inconsistencies, which linked to dyslexic motor patterns. These results align computational predictions with cognitive evidence, enhancing transparency and diagnostic value. The proposed model offers a practical and explainable approach for early neurocognitive prediction of dyslexia through handwriting analysis.
RETROSPECTIVE ANALYSIS IN HYPOTHESIS TESTING TO EVALUATE INDONESIA'S GINI RATIO AFTER COVID-19 PANDEMIC Karunia Eka Lestari, Fitriani Agustina, Mokhammad Ridwan Yudhanegara, Edwin Setiawan Nugraha, Sisilia Sylviani Barekeng, 2024 The study highlighted three essential roles of retrospective analysis in hypothesis testing, particularly as a priori analysis, post hoc analysis, and sensitivity analysis. These approaches were applied to the Gini ratio data sourced from the National Socioeconomic Survey Indonesia 2023 to examine the income inequality level in Indonesia. The sample size, statistical power, and effect size for the one-sample t-test are evaluated by aid G*Power software. The test results show that for a sample size of 10, at the 95% confidence interval, there is not enough evidence to show that the Gini ratio in 2023 is smaller than 0.4. A retrospective analysis using G*power software reveals that for a sample size of 20 at the same confidence interval, there is enough evidence to suggest that the Gini ratio is statistically significant at less than 0.4 with a power of analysis of 90.8% and an effect size of 0.76. This study has important implications in hypothesis testing, especially in retrospective analysis, since understanding the effect of sample size and effect size makes it possible for academics or practitioners to optimize hypothesis testing and generate more accurate and reliable test results.
CORRESPONDENCE ANALYSIS ON STATISTICAL LITERACY AND GENDER: EMBEDDING E-CAMPUS PLATFORM WITH RANDOM ASSIGNMENT OF MATCHED SUBJECT IN EXPLANATORY ANALYSIS Karunia Eka Lestari, Risnawita Risnawita, Mokhammad Ridwan Yudhanegara, Edwin Setiawan Nugraha, Sisilia Sylviani Barekeng, 2024 This study aims to evaluate the embedding of e-campus platforms during the pandemic in dealing with gender disparities in statistical literacy and shed light on the association structure between statistical literacy and gender disparities. A mixed methods approach with sequential explanatory analysis was performed among 42 pairs (man-woman) sample of sophomore students enrolled in the Inferential Statistics course selected from a random assignment of matched subjects. The two main instruments, the placement test, and the statistical literacy test, were analyzed quantitatively using the Mann-Whitney test and correspondence analysis, followed by qualitative analysis using image and text analysis. The findings reveal that the e-campus platform has increased women's statistical literacy. Specifically, there is a statistically significant difference (1) between men's and women's statistical literacy scores, (2) an association between statistical literacy level and gender, and (3) different tendencies between men's and women's statistical literacy in various ways. The e-campus platform is an excellent solution for the teaching and learning process during the COVID-19 pandemic and beyond. Likewise, it can overcome gender disparities in literacy statistics. Since these findings lead to a higher statistical literacy rate for women than men, this could break the stereotype that women are less statistically literate than men.
Elliptic Confidence on Correspondence Analysis Stainless Steels Corrosion Problem Engineering Letters, 2024
PREDICTIVE DISTRIBUTION TO DETERMINE LEARNING MODEL AT THE STRATEGIC COMPETENCE LEVEL OF STUDENTS IN STATISTICS GROUP COURSE Mokhammad Ridwan Yudhanegara, Karunia Eka Lestari Barekeng, 2024 The problem of this research comes from a situation or condition that is not static. The description of these problems is the condition of the learning system, which tends to change due to the Covid-19 pandemic, causing learning conditions to be dynamic. From a statistical perspective, the dynamic situation can be modeled using a predictive distribution approach, so its characteristics can be studied. The purpose is to provide policy recommendations on appropriate learning models for lecturers in improving students' strategic competence, which is an ability that students need to master in solving various mathematical problems. The main discussion of this paper consists of three parts: clustering, predictive distribution, and statistical inference. The purpose of clustering is to group students based on test results to determine the level of strategic competence. In addition, clustering is also used as an initial process to predict students' strategic competence level if the learning used is still the same. The benefits of statistical inference in the distribution procedure in this study are used to determine the type of data distribution from each arrival of new information or data. The results of the statistical inference determine whether or not it is necessary to update the learning model of the lecturer. This research produce a new alternative statistical inference needed to make decisions. Based on the simulation results and discussion, the use of a predictive distribution approach to predict dynamic data is very appropriate. Distribution approach can use for detecting changes in new data distribution with historical data for the dynamic condition. If the changes are insignificant, direct instruction can still be used for the learning model in statistics course. A new learning model is recommended for the statistics group course at a higher level when the changes are significant.
Empirical Study of Mathematical Investigation Skill on Graph Theory Mathematics Teaching Research Journal, 2024
Neurocognitive prediction of dyslexic handwriting pattern using an explainable AI-driven custom LiteBinaryNet-CNN KE Lestari, S Winarni, A Prihandhika, ES Nugraha, MR Yudhanegara Commun. Math. Biol. Neurosci. 2025, Article ID 141 , 2025 2025 Citations: 1
STRUKTUR ASOSIASI ANTARA KEMAMPUAN AWAL DAN KEMAMPUAN BERPIKIR KOMPUTASI MATEMATIS SISWA PADA SEKOLAH MENENGAH ATAS N Yasmin, KE Lestari Laplace: Jurnal Pendidikan Matematika 8 (2), 844-853 , 2025 2025 Citations: 1
Clustering Company Profitability from the IDX30 Index Using K-Medoids and DBSCAN ES Nugraha, AIS Wardhani, KE Lestari 2025 1st International Conference on Artificial Intelligence Technology … , 2025 2025
Efektivitas Pembelajaran Brain-Based Learning Terhadap Peningkatan Kemampuan Berpikir Logis Matematis Siswa KE Lestari Polinomial: Jurnal Pendidikan Matematika 4 (4), 883-891 , 2025 2025 Citations: 1
Model Persamaan Diskriminan untuk Prediksi Gaya Belajar Selmes Berdasarkan Kemampuan Metakognisi FN Arielhan, KE Lestari Polinomial: Jurnal Pendidikan Matematika 4 (3), 807-819 , 2025 2025 Citations: 1
Klasterisasi Siswa Sekolah Menengah Atas Berdasarkan Kemampuan Literasi Matematis dan Kemampuan Numerasi A Azkannaila, KE Lestari Polinomial: Jurnal Pendidikan Matematika 4 (3), 498-506 , 2025 2025 Citations: 1
Identifikasi Karakteristik Siswa Berdasarkan Kemampuan Representasi dan Pembuktian Matematis Menggunakan Pengelompokan K-Means DS Maharani, KE Lestari Polinomial: Jurnal Pendidikan Matematika 4 (3), 384-394 , 2025 2025 Citations: 1
Tucker3 Tensor Decomposition for the Standardized Residual Hypermatrix on Three-Way Correspondence Analysis KE Lestari, MR Yudhanegara, ES Nugraha, S Sylviani Journal of the Indonesian Mathematical Society 31 (2), 1491-1491 , 2025 2025
CLUSTERING BASED ON BETWEENNESS CENTRALITY IN PERIOD: TRANSFORMATION OF CORRELATION COEFFICIENT VALUE INTO DISTANCE IN MATRIC SPACE MR Yudhanegara, ES Nugraha, S Sylviani, KE Lestari, E Bonyah BAREKENG: Jurnal Ilmu Matematika dan Terapan 19 (2), 1109-1118 , 2025 2025 Citations: 1
Estimation of Value at Risk for General Insurance Company Stocks Using the Garch Model ES Nugraha, A Olivia, FNF Sudding, KE Lestari Barekeng: Jurnal Ilmu Matematika dan Terapan 19 (2), 1071-1082 , 2025 2025 Citations: 2
Penerapan Tpack: Modul Ajar dan Media Digital yang Berfokus pada Kemampuan Literasi dan Numerasi MRY Siswadi, MR Yudhanegara, KE Lestari, HI Umam Jurnal Pengabdian Kepada Masyarakat 6, 461-473 , 2025 2025 Citations: 2
Revealing the hidden pattern of under-five malnutrition prevalence distribution in West Java-Indonesia from canonical correspondence analysis and predictive clustering perspective KE Lestari, A Warmi, S Winarni, S Sylviani, ES Nugraha, ... Commun. Math. Biol. Neurosci. 2024, Article ID 132 , 2024 2024
Pemanfaatan Media Manipulatif “Mata Uanga” untuk Pembelajaran Siswa Di Sekolah Inklusi Karawang A Warmi, KE Lestari, DA Putri, M Kusumawardani, W Wiwin J-ABDIPAMAS (Jurnal Pengabdian Kepada Masyarakat) 8 (2), 65-71 , 2024 2024 Citations: 1
The contribution biplot on correspondence analysis to investigate the floricultural crops production in West Java KE Lestari, MR Utami, MR Yudhanegara AIP Conference Proceedings 2867 (1), 020007 , 2024 2024 Citations: 1
RETROSPECTIVE ANALYSIS IN HYPOTHESIS TESTING TO EVALUATE INDONESIA'S GINI RATIO AFTER COVID-19 PANDEMIC KE Lestari, F Agustina, MR Yudhanegara, ES Nugraha, S Sylviani BAREKENG: Jurnal Ilmu Matematika dan Terapan 18 (4), 2517-2530 , 2024 2024
Analisis Kemampuan Pemecahan Masalah Matematis Siswa SMP Dalam Soal Sistem Persamaan Linear Dua Variabel Y Cahyana, KE Lestari, AP Abadi Jurnal Educatio FKIP UNMA 10 (3) , 2024 2024 Citations: 1
CORRESPONDENCE ANALYSIS ON STATISTICAL LITERACY AND GENDER: EMBEDDING E-CAMPUS PLATFORM WITH RANDOM ASSIGNMENT OF MATCHED SUBJECT IN EXPLANATORY ANALYSIS KE Lestari, R Risnawita, MR Yudhanegara, ES Nugraha, S Sylviani BAREKENG: Jurnal Ilmu Matematika dan Terapan 18 (3), 1975-1988 , 2024 2024
Pengaruh Kemampuan Eksplorasi Matematis Terhadap Kemampuan Berpikir Kritis Matematis Siswa AA Rahman, KE Lestari Didactical Mathematics 6 (2), 212-221 , 2024 2024 Citations: 2
Pengaruh Kemampuan Elaborasi Terhadap Kemampuan Berpikir Kreatif Matematis N Istiqomah, KE Lestari Didactical Mathematics 6 (2), 164-170 , 2024 2024 Citations: 2
Elliptic Confidence on Correspondence Analysis Stainless Steels Corrosion Problem. YS Afrianti, US Pasaribu, H Ardy, KE Lestari Engineering Letters 32 (7) , 2024 2024 Citations: 2
MOST CITED SCHOLAR PUBLICATIONS
Penelitian Pendidikan Matematika KE Lestari, MR Yudhanegara Cetakan Pertama, Refika Aditama , 2015 2015 Citations: 5410
Implementasi Brain-Based Learning untuk meningkatkan kemampuan koneksi dan kemampuan berpikir kritis serta motivasi belajar siswa SMP KE Lestari Judika (Jurnal pendidikan UNSIKA) 2 (1) , 2014 2014 Citations: 255
Penelitian Pendidikan Matematika Edisi Kedua KE Lestari, MR Yudhanegara Bandung: PT. Refika Aditama , 2017 2017 Citations: 186
Meningkatkan kemampuan representasi beragam matematis siswa melalui pembelajaran berbasis masalah terbuka MR Yudhanegara, KE Lestari Majalah Ilmiah Solusi 1 (03) , 2014 2014 Citations: 96
Analisis motivasi belajar siswa terhadap hasil belajar matematika A Budiyani, R Marlina, KE Lestari Maju 8 (2), 502080 , 2021 2021 Citations: 68
Penelitian Pendidikan Matematika KE Lestari, MR Yudhanegara Cetakan Ketiga, Refika Aditama , 2018 2018 Citations: 68
Analisis kemampuan representasi matematis mahasiswa pada mata kuliah geometri transformasi berdasarkan latar belakang pendidikan menengah KE Lestari, MR Yudhanegara Jurnal Matematika Integratif 13 (1), 28-33 , 2017 2017 Citations: 62
Analisis kemampuan pembuktian matematis mahasiswa menggunakan pendekatan induktif-deduktif pada mata kuliah analisis real KE Lestari MENDIDIK: Jurnal kajian pendidikan dan pengajaran , 2015 2015 Citations: 59
Penelitian Pendidikan Matematika KE Lestari, MR Yudhanegara Edisi Revisi, Refika Aditama , 2017 2017 Citations: 43
Penerapan model pembelajaran M-APOS untuk meningkatkan kemampuan pemecahan masalah matematis siswa SMP KE Lestari JUDIKA (JURNAL PENDIDIKAN UNSIKA) 3 (1) , 2015 2015 Citations: 39
Generating roots of cubic polynomials by Cardano's approach on correspondence analysis KE Lestari, US Pasaribu, SW Indratno, H Garminia Heliyon 6 (6) , 2020 2020 Citations: 34
Analisis kemampuan literasi matematis siswa dalam menyelesaikan soal pisa konten space and shape ditinjau dari level kemampuan spasial matematis AS Fitriana, KE Lestari JPMI (Jurnal Pembelajaran Matematika Inovatif) 5 (3), 859-868 , 2022 2022 Citations: 31
Efektivitas model connected mathematics project terhadap kemampuan penalaran matematis dan kecemasan matematika E Aprillia, KE Lestari Jurnal Educatio FKIP UNMA 8 (3), 873-882 , 2022 2022 Citations: 22
Clustering for multi-dimensional data set: a case study on educational data MR Yudhanegara, KE Lestari Journal of Physics: Conference Series 1280 (4), 042025 , 2019 2019 Citations: 21
Exploratory Analysis on Adaptive Reasoning of Undergraduate Student in Statistical Inference. KE Lestari, MR Utami, MR Yudhanegara International Journal of Instruction 15 (4) , 2022 2022 Citations: 20
Analisis Kemampuan Literasi Matematis Siswa Kelas X SMA dalam Menyelesaikan Soal PISA A Amelia, KN Effendi, K Lestari Majamath: Jurnal Matematika Dan Pendidikan Matematika 4 (2), 136-145 , 2021 2021 Citations: 18
Implementasi Brain-Based Learning untuk Meningkatkan Kemampuan Koneksi dan Kemampuan Berpikir Kritis Matematis Siswa Sekolah Menengah Pertama KE Lestari Jurnal Pendidikan Unsika 2 (1) , 2013 2013 Citations: 17
Analisis kelancaran prosedural matematis siswa berdasarkan kemandirian belajar A Safitri, KE Lestari Jurnal Educatio FKIP UNMA 8 (2), 444-452 , 2022 2022 Citations: 16
Digital puzzle worksheet for identifying metacognition level of students: A study of gender differences AP Abadi, DS Aisyah, KE Lestari, MR Yudhanegara European Journal of Educational Research 12 (2), 795-810 , 2023 2023 Citations: 14
How to Develop Students' Experience on Mathematical Proof in Group Theory Course by Conditioning-Reinforcement-Scaffolding MR Yudhanegara, KE Lestari 5th SEA-DR (South East Asia Development Research) International Conference … , 2017 2017 Citations: 14