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All Journal Media Statistika Jurnal Ilmu Dasar Statistika Jurnal Matematika & Sains Telematika Jurnal Fourier Jurnal Sains Matematika dan Statistika PERFORMA : Media Ilmiah Teknik Industri Jurnal Teknik Industri: Jurnal Keilmuan dan Aplikasi Teknik Industri BAREKENG: Jurnal Ilmu Matematika dan Terapan IJID (International Journal on Informatics for Development) Journal of Industrial Engineering and Halal Industries JURTI Jurnal Teknik Industri STATISTIKA
Epha Diana Supandi
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Religion Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Energy Engineering Industrial & Manufacturing Engineering Mathematics Mechanical Engineering Physics Transportation

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A Full-Profile Conjoint Analysis to Identify University Students’ Preferences Toward Food Delivery Services: A Case Study of the Faculty of Science and Technology, UIN Sunan Kalijaga Yogyakarta Supandi, Epha Diana; Rochmiyani, Fitri
Journal of Industrial Engineering and Halal Industries Vol. 6 No. 2 (2025): Journal of Industrial Engineering and Halal Industries (JIEHIS)
Publisher : Industrial Engineering Department, Faculty of Science and Engineering, UIN Sunan Kalijaga Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14421/jiehis.5592

Abstract

The rapid development of digital technology has transformed consumer behavior, particularly in fulfilling food needs through online food delivery services. University students represent one of the most active user groups due to their high mobility and preference for practical lifestyles. This study aims to analyze students’ preferences toward food delivery service attributes and to identify the most influential factors in determining their choices. The research involved 100 respondents from the Faculty of Science and Technology, Universitas Islam Negeri Sunan Kalijaga Yogyakarta, using the traditional conjoint analysis method with a full-profile design approach. Six attributes were examined: type of service, price, payment method, courier service, food quality, and service quality. The results indicate that price has the highest level of importance (25.401%), followed by type of service (22.230%), service quality (16.231%), courier service (15.926%), payment method (10.960%), and food quality (9.252%). The most preferred combination of attributes includes GrabFood or GoFood services with promotional prices, uniformed couriers, diverse food options, and fast delivery. These findings suggest that promotional pricing strategies and service quality improvements are key factors for online food delivery providers to enhance customer satisfaction and attract student users.
Portfolio Risk Assessment Using VaR and CVaR: A Comparative Study of Variance–Covariance Method and Monte Carlo Simulation Epha Diana Supandi; Atika Oktavia
Telematika Vol 19, No 1: February (2026)
Publisher : Universitas Amikom Purwokerto

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35671/telematika.v19i1.3120

Abstract

This study examines portfolio risk in Indonesia’s energy sector by applying Value at Risk (VaR) and Conditional Value at Risk (CVaR) under the Variance–Covariance and Monte Carlo Simulation approaches. The analysis focuses on ten stocks from the oil and gas as well as coal subsectors listed on the Indonesia Stock Exchange (IDX), using monthly closing price data from January 2020 to December 2024. A Weighted Scoring Method (WSM) is first employed to select stocks with superior fundamentals and liquidity, based on market capitalization, return on equity, debt-to-equity ratio, net profit margin, trading volume, and dividend yield. An optimal portfolio is then constructed using the Maximum Sharpe Ratio (MSR) framework, resulting in a portfolio dominated by PTBA, MEDC, and MBAP. Portfolio risk is subsequently estimated using VaR and CVaR at the 95% and 99% confidence levels under both the Variance–Covariance and Monte Carlo approaches. The empirical results indicate that CVaR consistently produces higher risk estimates than VaR, highlighting its superior ability to capture tail risk. Furthermore, the Variance–Covariance method yields slightly more conservative CVaR estimates compared to Monte Carlo Simulation, which is attributed to the near-normal distribution of portfolio returns during the observation period. Model validity is confirmed through backtesting using the Kupiec test, which shows that the VaR estimates satisfy statistical adequacy criteria. Overall, the findings suggest that while the Variance–Covariance approach remains effective under normality assumptions, Monte Carlo Simulation offers greater flexibility in modeling extreme market conditions. This study contributes to the literature by providing empirical evidence on comparative risk estimation methods in Indonesia’s highly volatile energy sector.
Fourier Series Nonparametric Regression Modeling in the Case of Rainfall in West Java Province Anatansyah Ayomi Anandari; Epha Diana Supandi; Muhammad Wakhid Musthofa
IJID (International Journal on Informatics for Development) Vol. 11 No. 1 (2022): IJID June
Publisher : Faculty of Science and Technology, Universitas Islam Negeri (UIN) Sunan Kalijaga Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14421/ijid.2022.3300

Abstract

The Fourier series is a trigonometric polynomial that has flexibility, so it adapts effectively to the local nature of the data. This Fourier series estimator is generally used when the data used is investigated for unknown patterns and there is a tendency for seasonal patterns. This study aims to determine the results of the best Fourier series nonparametric regression model and the level of accuracy of the Fourier series nonparametric regression model on rainfall data by month in West Java Province in 2015-2019. This research is about a nonparametric regression model of Fourier series which is estimated using Ordinary Least Square method. Nonparametric regression using the Fourier series approach was applied to Rainfall data in West Java Province in 2015-2019. The independent variables used were the average air humidity, air pressure, wind speed, and air temperature. The model used to model the amount of rainfall in West Java Province is a nonparametric Fourier series. The nonparametric regression model is the best Fourier series with K =13 values obtained Generalized Cross Validation, Mean Square Error, and R2 respectively at 549.92; 462.09; and 97.30%. The results showed that the variables of air humidity and air pressure had a significant effect on rainfall.
Analisis Structural Equation Modeling Partial Least Square Terhadap Faktor Yang Mempengaruhi Keputusan Pembelian Konsumen Pada Produk AMDK Cindy Caroline; Ira Setyawati; Epha Diana Supandi
Performa: Media Ilmiah Teknik Industri Vol 23, No 1 (2024): Performa: Media Ilmiah Teknik Industri
Publisher : Industrial Engineering, Faculty of Engineering, Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/performa.23.1.84210

Abstract

Increasingly fierce competition requires companies to produce a good brand image. This encourages entrepreneurs to be more effective, efficient, creative, innovative and adaptive, so that companies are able to choose the right strategy. Companies need to know the position of their product brands in the minds of consumers and then develop strategies to further increase consumer loyalty. This study was conducted to analyze the factors of quality, price, and brand image on purchasing decisions. Data analysis was carried out by Partial Least Square - Structural Equation Model using SmartPLS statistical software. With the results of the R2 output of 64% and the significance test with the bootstrapping process, the price, quality and brand image factors have a significant influence on purchasing decisions. The variable that has the most influence on purchasing decisions is brand image with an original sample value of 0.426.
Co-Authors Abdurakhman Abdurakhman Akhmad Fauzy Anatansyah Ayomi Anandari Anatansyah Ayomi Anandari Atika Oktavia Cindy Caroline Dedi Rosadi Eka Nur Vanti Ira Setyaningsih Ira Setyawati Jana, Padrul Luh Putu Ratna Sundari Mohd. Rizam Abu Bakar Muhammad Wakhid Musthofa Noor Saif Muhammad Mussafi Pipit Pratiwi Rahayu PRAMONO, YUDA EKA Riska Yulianti Rochmiyani, Fitri Sri Puji Lestari Vanti, Eka Nur Veladita Apriyanti Wahyu Suryadi Suryadi Widiawati, Alfina Viona Isabela Yogi Anggara Zain, Zuva Amalina