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Djoni Hatidja
Department Of Mathematics, Sam Ratulangi University, Manado
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Engineering Environmental Science Languange, Linguistic, Communication & Media Mathematics Physics Public Health

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Journal : Operations Research: International Conference Series

 1 
Comparing the Performance of Prediction Model of Ridge and Elastic Net in Correlated Dataset Bastiaan, Richy Marcelino; Salaki, Deiby Tineke; Hatidja, Djoni
Operations Research: International Conference Series Vol. 3 No. 1 (2022): Operations Research International Conference Series (ORICS), March 2022
Publisher : Indonesian Operations Research Association (IORA)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47194/orics.v3i1.127

Abstract

Multicollinearity refers to a condition where high correlation between independent variables in linear regression model occurs.  In this case, using ordinary least squares (OLS) leads to unstable model. Some penalized regression approaches such as ridge and elastic-net regression can be applied to overcome the problem. Penalized regression estimates model by adding a constrain on the size of parameter regression. In this study, simulation dataset is generated, comprised of 100 observation and 95 independent variables with high correlation. This empirical study shows that elastic-net method outperforms the ridge regression and OLS.  In correlated dataset, the OLS is failed to produce a prediction model based on mean squared error (MSE)
Distribution of Spread and Characteristics of Confirmed Covid-19 based on Spatial Autocorrelation in Manado Pontoh, Sophia Olga; Weku, Winsy; Hatidja, Djoni
Operations Research: International Conference Series Vol. 3 No. 1 (2022): Operations Research International Conference Series (ORICS), March 2022
Publisher : Indonesian Operations Research Association (IORA)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47194/orics.v3i1.128

Abstract

Covid-19 is a collection of viruses that attack the respiratory system. This virus spread quickly and spread to other regions in China and most countries in the world, including Indonesia. North Sulawesi Province, especially Manado City is one of the cities in Indonesia that has been affected by Covid-19. The highest confirmed Covid-19 cases in Manado City are in the Malalayang, Mapanget, and Wanea villages which are geographically not adjacent/neighboring. This study aims to analyze the spatial distribution of Covid-19 cases and their characteristics. This study uses significant data on Covid-19 cases in every village in Manado City, where there are 86 villages (Malayang Satu Barat Village and Malalayang Satu Timur Village combined), and the focus of this research is on the confirmed variables, with the latest data update is October 21, 2021. The effect of covid-19 between observation locations is accomplished using Moran's I, and the weighting matrix used is the Euclidean distance matrix. The Moran's Index provides an overview of the spatial relevance of the Covid-19 case data in every village in Manado City and specifically the spatial attachment of every village will be explained by the Local Moran's I value (LISA). The results of this study found that there is a spatial autocorrelation found using the Euclidean distance matrix. A spatial correlogram of 30 meters is used as the maximum geographical distance limit for being infected with Covid-19. The Moran's Index value of the Covid-19 case in Manado City is 0.348, meaning that there is a positive autocorrelation between the villages. There are thirteen villages that affect the spread of Covid-19 in Manado City, namely Malalayang Satu Timur dan Barat, Malalayang Satu, Winangun Satu, Kleak, Karombasan Utara, Ranotana Weru, Bumi Nyiur, Pakowa, Tinkulu, Taas, Paal Empat, Tikala Baru, and Paniki Dua.
Co-Authors Adianto Pakkung Alfrina Alfrina Alfrina, Alfrina Altien J. Rindengan Andar Alwein Pinilas Arini Mamangkey Aron F Pualalo Audy Denny Wuntu Bastiaan, Richy Marcelino Belenehu, Fiqih Syaukani Budiman, Ripit Chandra Purwanto Charles E Mongi Charles E Mongi Charles E. Mongi Charles E. Mongi Chirdy Onibala, Chirdy Christian Alderi Jeffta Soewoeh Christian Y Lumenta Deiby T Salaki Denis G. Allo Djaka Liputo Eka Elencya Trisilia Laloan Eliasta Ketaren, Eliasta Faranika Deysi G Maneking Fiqih Syaukani Belenehu Geovani Christie Greis S Lilipaly Hanny Komalig Hanny Komlaig Hanny Komlaig Harikadua, Meilissa Iriansu, Irfah Syagitsyah Jamner Lawendatu Janet Graciela Paruntu Jantje D Prang Jantje D Prang Jantje D Prang Jantje D. Prang Jaqualine Tinungki Jaqualine Tinungki John S Kekenusa John Socrates Kekenusa Josua A.S Pamekas Jullia Titaley Julyanti S Malensang Kaplale, Jaidun Ramadhan Komalig, Hanny Andrea Huibert Leivy G. Paruntu Lengkong, Vanda Lidya I Momuat Lidya I Momuat Lidya Irma Momuat Luther Latumakulita Mandagi, Tamariska Ega Tabitha Maneking, Faranika Deysi G Mans Mananohas Mans Mananohas, Mans Mapalie, Natassya Klarissa Ribka Marline Paendong Marline S Paendong Marsela Pangalila Mega Sriningsih Meilissa Harikadua Melky Sepang, Melky Momuat, Lidya Muliyati Gugutu Nelson Nainggolan NELSON NAINGGOLAN Nelson Nainggolan Nelson Nainggolan Pamekas, Josua A.S Pantow, Yehuda Paruntu, Janet Graciela Paruntu, Leivy G. Patrix Rembang Pontoh, Sophia Olga Prastika Tumilaar Pualalo, Aron F Redianus Daman Rembang, Patrix Ridel Runturambi Rindengan, Altien J. Rinny Tutud Ripit Budiman Runtu, Marini Runturambi, Ridel Sagai, Friska Sanriomi Sintaro Selfina Clara Wohon Sinnyo Salmon, Sinnyo Sriningsih, Mega Stefano Kasal Taarega Taarega, Stefano Kasal Tamariska Ega Tabitha Mandagi Tohap Manurung Trisnawaty V. Gobel Tumilaar, Rinancy Tutud, Rinny Victor N.R Watung Wawo, Rohelio Yoel Winsy Christo Deilan Weku Winsy Christo Deilan Weku Winsy Weku Wisard Widsli Kalengkongan Wohon, Selfina Clara Yohana Pangemanan Yohanes A. R. Langi Yohanes A.R Langi Yohanes A.R Langi Yohanes A.R. Langi Yohanes Langi Yulianti Talungke, Yulianti