Judul: Cost Planning for Rice Straw Transportation as Feedstock  for Biomethane Liquid Natural Gas (Bio-LNG) in Karawang Regency.
Abstrak: Melimpahnya jumlah limbah jerami padi yang dihasilkan setiap tahunnya serta kurangnya pemanfaatan limbah tersebut menyebabkan permasalahan serius, salah satunya yaitu menjadi penyumbang dalam terbentuk emisi gas rumah kaca. Upaya yang harus dilakukan oleh pemerintah Indonesia yaitu melakukan pemanfaatan dan pengembangan EBT dalam bentuk Bio-LNG yang bersumber dari jerami padi sebagai bahan baku utama. Dalam usaha pengembangannya PT XYZ menghadapi masalah dalam hal transportasi pengangkutan bahan baku dari pemasok menuju pabrik. Adapun tujuan dari penelitian ini yaitu menganalisis biaya transportasi dan biaya pengadaan jerami padi pada PT XYZ. Penelitian ini dilakukan pada bulan Desember 2022 hingga Juli 2023 dan dilaksanakan di Kabupaten Karawang. Metode yang digunakan dalam penelitian ini yaitu metode transportasi yang terdiri dari dua tahap yaitu mencari solusi awal dengan vogel’s approximation method (VAM) dan uji optimalisasi dengan modified distribution (MODI). Hasil dari penelitian ini menunjukan bahwa biaya transportasi dipengaruhi oleh jarak dan juga kesedian supply jerami padi setiap bulannya, semakin jauh dan sedikitnya supply jerami padi pada setiap kecamatan maka semakin besar juga biaya transportasi yang dikeluarkan., The abundance of rice straw waste generated annually in Indonesia, along with the insufficient utilization of this waste, results in serious issues, one of which is its contribution to greenhouse gas emissions. The Indonesian government's effort to address this problem involves the utilization and development of Renewable Energy sources in the form of Bio-LNG derived from rice straw as the primary raw material. During the development process, PT XYZ encountered challenges related to the transportation of raw materials from suppliers to the factory. The purpose of this research is to analyze the transportation costs, and analyze the procurement costs of rice straw at PT XYZ. The study was conducted between December 2022 and July 2023 in the Karawang Regency. The research method employed for transportation cost analysis consisted of two stages: the initial solution search using Vogel's Approximation Method (VAM) and the optimization test using the Modified Distribution (MODI) approach. The research findings indicate that transportation costs are influenced by distance and the availability of rice straw supply on a monthly basis. The farther the distance and the lower the availability of rice straw supply in each sub-district, the greater the transportation costs incurred.
Keyword: Bio_LNG, Rice Straw, Transportation Method

Judul: Transportation Cost Planning of Rice Straw as Raw Material for Bio-LNG Manufacturing in Indramayu Regency
Abstrak: Industri bioenergi di Indonesia memiliki persentase terkecil sebesar 4% dari total penghasil emisi gas metana di sektor energi. Hal ini membuka peluang untuk mengembangkan Bio-LNG sebagai salah satu bentuk bioenergi dan sesuai dengan Rencana Umum Energi Nasional dan mendukung SDG 7 Energi Bersih dan Terjangkau. Jerami padi merupakan salah satu bahan baku Bio-LNG. PT XY yang merupakan perusaahaan pengembangan energi, berencana membangun pabrik pengolahan Bio-LNG di Kabupaten Indramayu dengan bahan baku dari jerami padi. Penelitian dilaksanakan di Kabupaten Indramayu pada bulan Desember 2022 sampai dengan Maret 2023 dengan tujuan menganalisis perencanaan biaya transportasi dan total biaya pengadaan jerami padi sebagai bahan baku Bio-LNG di Kabupaten Indramayu. Solusi optimum awal diperoleh menggunakan Vogel’s Approximation Method dan uji optimalitas menggunakan Modified Distribution. Hasil penelitian menunjukkan bahwa biaya transportasi jerami padi di Kabupaten Indramayu dipengaruhi oleh jarak dari pemasok ke pabrik dan jumlah jerami padi yang dapat diangkut dalam satu kali perjalanan. Semakin jauh jarak dari pemasok ke gudang mengakibatkan biaya transportasi semakin besar., The bioenergy industry in Indonesia has the smallest percentage of 4% of the total methane gas emitters in the energy sector. This opens up opportunities to develop Bio-LNG as a form of bioenergy and is in line with the National Energy General Plan and supports SDG 7 Clean and Affordable Energy. Rice straw is one of the raw materials for Bio-LNG. PT XY, an energy development company, plans to build a Bio-LNG processing plant in Indramayu Regency with raw materials from rice straw. The research was conducted in Indramayu Regency from December 2022 to March 2023 with the aim of analyzing transportation cost planning and the total cost of procuring rice straw as raw material for Bio-LNG in Indramayu Regency. The initial optimum solution was obtained using Vogel's Approximation Method and optimality test using Modified Distribution. The results showed that the transportation cost of rice straw in Indramayu Regency is influenced by the distance from the supplier to the factory and the amount of rice straw that can be transported in one trip. The longer the distance from the supplier to the warehouse results in greater transportation costs.
Keyword: bio-lng, rice straw, transportation, Sdgs

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology