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Journal : Science and Technology Indonesia

Greedy Reduction Algorithm as the Heuristic Approach in Determining the Temporary Waste Disposal Sites in Sukarami Sub-District, Palembang, Indonesia Sisca Octarina; Fitri Maya Puspita; Siti Suzlin Supadi; Nur Attina Eliza
Science and Technology Indonesia Vol. 7 No. 4 (2022): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1079.812 KB) | DOI: 10.26554/sti.2022.7.4.469-480

Abstract

Waste is one of the problems in Palembang, Indonesia. The amount of waste in Palembang increases proportionally to the population yearly and can adversely affect the community. Therefore, we determine the optimal temporary waste disposal site (TWDS) to optimize the problems. The set covering model is the proper model for solving the location and allocation problem. In this study, data on the distance between each TWDS is needed in the set covering modeling. The novelty in this research is developing the p-median problem model, which is formed from the optimal solution of the set covering location problem (SCLP) model. Palembang consists of 18 sub-districts, of which the Sukarami sub-district has the highest population density. This study discussed the determination of strategic TWDS in the Sukarami sub-district using the SCLP model, the p-median problem, and a heuristic approach, namely the greedy reduction algorithm in solving the model. Based on the solution of the p-median problem model with LINGO 18.0 and the p-median problem solved by the greedy reduction algorithm, only three strategic TWDS were found for the Sukarami sub-district. The study results recommend a review of the existing TWDS and particularly the addition of a TWDS in Sukodadi and Talang Betutu villages, respectively.
3-Phase Matheuristic Model in Two-Dimensional Cutting Stock Problem of Triangular Shape Items Putra Bahtera Jaya Bangun; Sisca Octarina; Sisca Puspita Sepriliani; Laila Hanum; Endro Sastro cahyono
Science and Technology Indonesia Vol. 5 No. 1 (2020): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1397.786 KB) | DOI: 10.26554/sti.2020.5.1.23-27

Abstract

Cutting Stock Problem (CSP) is a problem of cutting stocks with certain cutting rules. This study used the data of rectangular stocks, which cut into triangular shape items with various order sizes. The Modified Branch and Bound Algorithm (MBBA) was used to determine the optimum cutting pattern then formulated it into the 3-Phase Matheuristic model which consisted of constructive phase, improvement phase, and compaction phase. Based on the results, it showed that the MBBA produces three optimum cutting patterns, which was used six times, eight times, and four times respectively to fulfill the consumer demand. Then the cutting patterns were formulated into the 3-Phase Matheuristic model whereas the optimum solution was the minimum trim loss for the first, second and third patterns.
Set Covering Model in Solving Multiple Cutting Stock Problem Sisca Octarina; Devi Gusmalia Juita; Ning Eliyati; Putra Bahtera Jaya Bangun
Science and Technology Indonesia Vol. 5 No. 4 (2020): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (943.33 KB) | DOI: 10.26554/sti.2020.5.4.121-130

Abstract

Cutting Stock Problem (CSP) is the determination of how to cut stocks into items with certain cutting rules. A diverse set of stocks is called multiple stock CSP. This study used Pattern Generation (PG) algorithm to determine cutting pattern, then formulated it into a Gilmore and Gomory model and solved by using Column Generation Technique (CGT). Set Covering model was generated from Gilmore and Gomory model. Based on the results, selected cutting patterns in the first stage can be used in the second stage. The combination of patterns generated from Gilmore and Gomory model showed that the use of stocks was more effective than Set Covering model.
Column Generation Model in Capacitated Multi-Periods Cutting Stock Problem with Pattern Set-Up Cost Putra Bahtera Jaya Bangun; Sisca Octarina; Laila Hanum; Ranti Sawitri; Endro Sastro Cahyono
Science and Technology Indonesia Vol. 6 No. 1 (2021): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1195.562 KB) | DOI: 10.26554/sti.2021.6.1.8-13

Abstract

Cutting Stock Problem (CSP) determines the cutting of stocks with standard length and width to meet the item’s demand. The optimal cutting pattern will minimize the usage of stocks and trim loss. This research implemented the pattern generation algorithm to form the Gilmore-Gomory and Column Generation model in two-dimensional CSP. The CSP in this research had three periods of cutting with different capacities in each period. The Column Generation model added the pattern set-up cost as the constraint. The Gilmore-Gomory model ensured that the first stage’s strips were used in the second stage and met the item’s demand. Based on the Column Generation model’s solution, the 1st period used the 2nd, 4th, and 5th patterns, the 2nd period used 4th and 5th patterns, and the 3rd period did not use any patterns. The first and second periods fulfilled all of the demands.
Analysis of Information Service Pricing Scheme Model Based on Customer Self-Selection Indrawati; Fitri Maya Puspita; Resmadona; Evi Yuliza; Oki Dwipurwani; Sisca Octarina
Science and Technology Indonesia Vol. 6 No. 4 (2021): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2021.6.4.337-343

Abstract

This study attempts to analyze pricing schemes with monitoring cost and marginal cost for perfect substitute and quasi-linear utility functions for achieving Internet service Provider (ISP) in gaining benefit. Two types of customers analyzed, namely customers who are heterogeneous (both high-end and low-end) as well as heterogeneous customers (high-demand and low-demand) based on Flat-fee, usage-based, and two-part tariff are the three types of pricing methods employed. The results show that usage-based pricing schemes gain maximum profit optimal for heterogeneous customers (high-end and low-end), while for heterogeneous customers (high-demand and low-demand) type of pricing scheme two-part tariff obtains maximum profit optimal. The results of this study are more directed to the lemma of the perfect substitute utility function which compares the lemma of heterogeneous customers. This model was solved using LINGO 13.0 software and ISP to get maximum profit.
Set Covering Model Using Greedy Heuristic Algorithm to Determine The Temporary Waste Disposal Sites in Palembang Putra Bahtera Jaya Bangun; Sisca Octarina; Rizka Aniza; Laila Hanum; Fitri Maya Puspita; Siti Suzlin Supadi
Science and Technology Indonesia Vol. 7 No. 1 (2022): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (986.328 KB) | DOI: 10.26554/sti.2022.7.1.98-105

Abstract

Optimizing the facility location has a vital role in providing services to the community. This study aims to determine the Temporary Waste Disposal Site (TWDS) in Sako District, Palembang City. The distance data between each TWDS in Sako District is used to formulate the Set Covering model, consisting of the Set Covering Location Problem (SCLP) model and the p-Median Problem model. The classical approach is made by solving both models using Lingo 18.0 software. The Greedy Heuristic algorithm is used as the heuristic approach. Based on the results and discussion, Sako District consists of 4 Villages and 9 TWDS. The SCLP and p-Median Problem models with LINGO 18.0 software and the Greedy Heuristic algorithm show a difference. The study results suggest using the optimal solution resulting from the Greedy Heuristic algorithm because it can meet all requests in Sako District. Research shows that there are six optimal TWDS in Sako District. However, several locations are still not optimal, so it is recommended that there are an additional 14 new TWDS facilities in Sako District to serve all requests.
Facility Location Problem of Dynamic Optimal Location of Hospital Emergency Department in Palembang Robinson Sitepu; Fitri Maya Puspita; Ide Lestari; Indrawati; Evi Yuliza; Sisca Octarina
Science and Technology Indonesia Vol. 7 No. 2 (2022): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1752.885 KB) | DOI: 10.26554/sti.2022.7.2.251-256

Abstract

The Emergency Department (ED) is one part of a hospital that provides initial treatment for patients who suffer from illness and injury, which can threaten their survival. The importance of integrated care in the ED is one of the keys to successfully treating patients at an advanced level. This becomes complex because the ED works in a team consisting of various multi-disciplinary sciences and limited human resources, facilities, and infrastructure. In the City of Palembang, 23 hospitals have emergency room facilities from 18 Sub-Districts, by using the TOPSIS (Technique for Others Reference by Similarity to Ideal Solution) method to vary the distance (radius) the optimal location of the emergency department is obtained according to the number of hospitals that have emergency room facilities, namely Ilir Timur I District, Ilir Barat I District, Sukarami District, and Plaju District. Based on the formulation of the p-median model and the completion of the TOPSIS method, the order of Districts that have optimal locations from 18 Sub-Districts that have emergency department facilities in the City of Palembang is obtained.
Waste Collection Vehicle Routing Problem with TimeWindows for Route Optimization of Garbage Transport Vehicles Evi Yuliza; Bambang Suprihatin; Putra Bahtera Jaya Bangun; Fitri Maya Puspita; Indrawati; Sisca Octarina
Science and Technology Indonesia Vol. 8 No. 1 (2023): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.1.66-70

Abstract

The waste collection vehicle routing problem with time windows is an optimization problem on the route of the waste transport vehicle which aims to determine the route of the vehicle by considering the travel time and windows. Garbage transport vehicles transport garbage in several work areas. This affects the optimal time and distance. The working hours of the garbage collectors are divided into two parts. The first working hours are 07.00 - 11.00 West Indonesian Time (WIT) and 16.00-20.00 WIT. The cleaning staff has a break of 5 hours. This study aims to optimize the route of waste transportation vehicles in the problem of transporting waste so as to minimize travel time and distance. Waste collection vehicle routing problem with time windows on determining the route of a garbage transport vehicle which is simulated on the problem of transporting garbage in the city of Palembang. The waste collection vehicle routing problem with the time windows model is solved with an exact approach using LINGO software. The results of this study indicate that the proposed optimization model provides optimization of the route of the garbage transport vehicle, the total travel time, and break time of the cleaning staff.
Formulation of Set Covering Problem Using Myopic Algorithm and Greedy Reduction Algorithm in Determining the Location of Temporary Landfills in Semambu Island Village, Ogan Ilir Regency, South Sumatra Fitri Maya Puspita; Sisca Octarina; Laila Hanum; Chatrin Yohana Simamora; Helena Valenta Br Kemit; Evi Yuliza
Science and Technology Indonesia Vol. 8 No. 2 (2023): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2023.8.2.184-194

Abstract

This study discusses Set Covering Problem (SCP) in designing the optimal temporary waste disposal site (TWDS) in Semambu Island Village using the Myopic Algorithm (MA) and Greedy Reduction Algorithm (GRA). The analysis was carried out and compared using a maximum distance of 500m and 1000m to get the best solution from two methods. The results of the p Median Problem by LINGO 13.0 software and MA with a maximum distance of 500m show the same TWDS location, namely Working Area (WA) 1, 2, 3, 4, 5, and 6 with the location of the candidate TWDS being at TWDS 2 WA 1, TWDS 1 WA 2, TWDS 2 WA 3, and TWDS 2 WA 5. For 1000m, it will be the location of the candidate’s TWDS being at TWDS 2 WA 1, TWDS WA 2, and TWDS 2 WA 3. Using GRA, results were obtained will be 4 TWDS, namely TWDS 2 Hamlet 1, TWDS 1 Hamlet 2, TWDS 2 Hamlet 3, TWDS 2, Hamlet 5. Then using GRA, 2 solutions are obtained, namely columns 2 and 5 which dominate. Column 2 nomination are Hamlets 1, 2, 3, and 6. Column 5 which dominates will be Hamlets 1, 3, 5, and 6.
Robust-Set Covering Problem and Sensitivity Analysis to Determine The Location of Temporary Waste Disposal Sites Octarina, Sisca; Bangun, Putra Bahtera Jaya; Cahyono, Endro Setyo; Suprihatin, Bambang; Sarjani, Ita; Puspita, Fitri Maya; Yuliza, Evi
Science and Technology Indonesia Vol. 9 No. 2 (2024): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2024.9.2.260-272

Abstract

The increasing population has resulted in a significant increase in the amount of waste. One effort that can be made to overcome the waste problem is to provide a Temporary Waste Disposal Site (TWDS). This research aims to optimize the TWDS in the Bukit Kecil sub-district, Palembang city, by formulating a Robust-Set Covering Problem (Robust-SCP) model and solving the model with the software. Sensitivity analysis is used to analyze the optimal solution. Bukit Kecil sub-district is the sub-district that has the highest number of TWDS in Palembang city. The robust-SCP model obtained 10 optimal TWDS. Therefore, this research recommends the Robust SCP model as the optimal solution for the determination of TWDS in the Bukit Kecil sub-district, namely TWDS Kartini Street, TWDS front of Starbucks KI Street, TWDS Merdeka Street, TWDS Illegal at 26 Ilir Market, TWDS Flat Block 35, TWDS Flat Block 49, TWDS Merdeka Women’s Prison, TWDS Musi Riverbank Park, TWDS Monpera, and TWDS Cinde Market, with the addition of TWDS Mayor’s Office in 22 Ilir village and TWDS Flat Block 01 in 23 Ilir village. The sensitivity analysis results in this study show that the solution remains optimal if the coefficient change is within the coefficient interval value.
Co-Authors Adik Ahmadi Adinda Putri Ramadhany, Adinda Putri Ahmadi, Adik Ani Sahara Br. Simanjuntak Aprilia Nur Sabana Armalia, Divasanda Aryani, Robeah Asri Kuntari Asri Kuntari, Asri Ayu Nursafitri Ayu Wulandari Bambang Suprihatin Bambang Suprihatin Belly Wardhani Chatrin Yohana Simamora Destia Maharani Devi Gusmalia Juita Dewi Lisandra Diyaz Rachmaningtiyaz Diyaz Rachmaningtyas Elisa Nurnawati Endro Sastro cahyono Endro Setyo Cahyono, Endro Setyo Evi Yuliza Evi Yuliza Evi Yuliza Evi Yuliza Evi Yuliza Evi Yuliza Evi Yuliza, Evi Fidella Oktariana Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Fitri Maya Puspita Gina Sonia Gusti Ahta Virgo Haryati Pane Helena Valenta Br Kemit Helmayanti, Rizky Hernanda, Eggyana Deri Ide Lestari Indrawati Indrawati Indrawati Indrawati Indrawati Indrawati Indrawati Indrawati Indrawati Indrawati Jaya Bangun Jurnal Pepadu Laila Hanum Maya Puspita, Fitri Miranda Avifana Nanang Suwandi Narasti Wulandari Ning Eliyati Novi Rustiana Dewi Nur Attina Eliza Oki Dwipurwani Oki Dwipurwani Putra Bahtera Putra Bahtera Jaya Bangun Putra Bahtera Jaya Bangun Putra Bahtera Jaya Bangun Putra Bahtera Jaya Bangun Putra Bahtera Jaya Bangun, Putra Bahtera Jaya Putra BJ Bangun, Putra BJ Putri Rahmadia Rachmaningtiyaz, Diyaz Rani Elekta Togatorop Ranti Sawitri Resmadona Reza Andeka Rika Apriani Rima Melati Rizka Aniza Robeah Aryani Robinson Sitepu Robinson Sitepu Robinson Sitepu Sabana, Aprilia Nur Sarjani, Ita Sisca Puspita Sepriliani Siti Suzlin Supadi Sugandi Yahdin Tasiah, Mawar Tri Handayani Venty Yolanda Fitria Yulia Anisawati YUNITA Yunita Yunita