Judul: Aplikasi Metode Modifikasi Aproksimasi Vogel Pada Masalah Distribusi Beras
Abstrak: Salah satu tugas pemerintah adalah menjaga ketahanan pangan Indonesia. Ketahanan pangan dapat ditingkatkan salah satunya melalui program raskin yang berada pada naungan Perum Bulog. Penelitian ini bertujuan untuk meminimumkan biaya distribusi raskin yang dikeluarkan oleh Perum Bulog Divisi Regional Jawa Timur menggunakan metode transportasi. Untuk mencari metode transportasi yang paling optimum dan efisien maka peneliti akan membandingkan beberapa metode. Metode yang dipakai diantaranya Metode Aproksimasi Vogel, Improved Vogel Approximation Method, Max-Min Vogel Approximation Method, dan juga Modified Vogel Approximation Method. Metode Aproksimasi Vogel merupakan metode yang paling optimum dan efisien karena menghasilkan biaya distribusi terendah dan metode yang paling cepat karena tidak perlu mencari matriks tereduksi seperti pada Modified Vogel Approximation Method. Total biaya pendistribusian raskin yang diperoleh pada penelitian ini adalah sebesar Rp501.735.413,00. Kata kunci: distribusi, metode pendekatan improved vogel, metode pendekatan max-min vogel, metode pendekatan modified vogel, metode aproksimasi vogel., One of the government's tasks is to maintain Indonesia's food security. One way to improve food security is through the Raskin program which is under the auspices of Perum Bulog. This research aims to minimize raskin distribution costs incurred by the East Java Regional Division of Perum Bulog using transportation methods. To find the most optimal and efficient transportation method, researchers will compare several methods. The methods used include the Vogel Approximation Method, the Improved Vogel Approximation Method, the Max-Min Vogel Approximation Method, and also the Modified Vogel Approximation Method. The Vogel Approximation Method is the most optimal and efficient method because it produces the lowest distribution costs and is the fastest method because there is no need to look for a reduced matrix as in the Modified Vogel Approximation Method. The total cost of distributing Raskin obtained in this research was Rp501,735,413.00. Keywords: distribution, improved vogel’s approximation method, max-min vogel’s approximation method, modified vogel’s approximation method, vogel’s approximation method.
Keyword: Distribution, improved vogel's approximation method, max-min vogel's approximation method, modified vogel's approximation method, vogel's approximation method

Judul: The Application of Genetic Algorithm in Vehicle Routing Problem and Its Implementation on Rastra Distribution
Abstrak: Rute pendistribusian kendaraan terkait proses distribusi produk merupakan masalah yang dihadapi produsen dalam memenuhi kebutuhan konsumen. Penentuan rute distribusi kendaraan atau vehicle routing problem (VRP) bertujuan menentukan rute dan penggunaan kendaraan agar biaya yang dikeluarkan minimal. Pada penelitian ini akan dibahas rute pendistribusian kendaraan untuk mengantarkan beras sejahtera dari beberapa gudang penyimpanan ke desa/kelurahan tertentu yang dimiliki Perum Bulog kabupaten Ponorogo untuk satu dari dua belas periode. Salah satu desa/kelurahan memiliki permintaan yang melebihi kapasitas kendaraan, sehingga lokasi tersebut dapat dikunjungi kendaraan dengan pendistribusian terpisah. VRP dapat diselesaikan menggunakan metode eksak dan metode heuristik. Metode heuristik genetic algorithm dengan pencarian solusi awal melalui nearest neighbour diterapkan untuk masalah pendistribusian beras pada periode di Perum Bulog. Solusi yang dihasilkan oleh metode heuristik memiliki waktu yang lebih cepat dibandingkan solusi metode eksak., The vehicle distribution route related to the product distribution process is a problem faced by manufacturers in meeting consumer needs. Determination of vehicle distribution routes or vehicle routing problem (VRP) aims to determine the route and use of vehicles so that the costs incurred are minimal. In this study the route of distribution of vehicles to deliver prosperous rice from several storage warehouses to certain villages will be discussed, which is owned by Perum Bulog in Ponorogo Regency for one of the twelve periods. One of the village has a demand that exceeds the vehicle capacity, so that the location can be visited by vehicles with split delivery. VRP can be solved using exact methods and heuristic methods. The heuristic genetic algorithm method by searching for an initial solution through the nearest neighbour is applied to the problem of distributing rice during the period at Perum Bulog. The solution produced by the heuristic methods has a faster time than the solution of the exact methods.
Keyword: distribution, heuristic method, multidepot, split delivery, vehicle routing problem

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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