Judul: Optimasi Hetereogeneous Fleet Vehicle Routing Problem with Time Windows pada Distribusi Produk Beku dengan Algoritma Genetika
Abstrak: Penentuan rute distribusi yang disebut sebagai vehicle routing problem (VRP) merupakan salah satu permasalahan dalam sistem distribusi. PT X merupakan perusahaan importir yang menyediakan berbagai produk beku seperti daging sapi, daging ayam, daging kerbau, hasil laut, kentang,dan lain-lain. Proses penentuan rute distribusi di PT X dilakukan berdasarkan jumlah permintaan yang tidak tetap untuk setiap harinya yang menyebabkan kapasitas kendaraan tidak terutilisasi secara maksimal sesuai dengan standar perusahaan yang harus dipenuhi minimal 80%. Penentuan rute distribusi dilakukan menggunakan perangkat lunak Locus yang seringkali ditemukan beberapa rute yang tidak sesuai titik dan rute yang tersedia lebih jauh mengakibatkan tidak terpenuhinya time windows sehingga terjadi keterlambatan. Oleh karena itu, diperlukan pengkajian ulang efisiensi sistem distribusi yang sudah ada. Penelitian ini bertujuan meminumumkan jarak distribusi dengan melakukan pencarian rute distribusi terpendek. Metode penelitian ini diantaranya adalah pengumpulan alamat konsumen sebagai data utama dan pengolahan data. Proses optimasi perncarian rute dilakukan menggunakan algoritma genetika. Berdasarkan hasil optimasi diperoleh pengurangan total jarak tempuh sebesar 149.1 km dan penurunan penggunaan jumlah kendaraan sebanyak 2 unit. Selain itu, terjadi peningkatan rata-rata utilitas kendaraan sebesar 2.64%. Melalui hasil tersebut metode Algoritma Genetika yang digunakan mampu menghasilkan rute distribusi yang lebih optimal.
Keyword: Distribution, Genetic Algorithm, Time Windows, Vehicle Routing Problem

Judul: Penyelesaian Vehicle Routing Problem pada Pendistribusian Sayuran Dataran Tinggi Menggunakan Algoritme Genetika (Studi Kasus PT Saung Mirwan)
Abstrak: Vehicle routing problem (VRP) is an important issue on a transportation system that aims at minimizing the total vehicle mileage to reduce vehicle operating cost to a minimum. Vehicle routing problem belongs to the class of non-polynomial hard (NP-hard), which generally uses a heuristic approach to find a solution. In this time, Vehicle routing problem resolution will be applied to the distribution of highland vegetables from PT. Saung Mirwan as the vegetable distribution center. The problems that often arise in the distribution of highland plain vegetables is to how minimize the total of transportation costs without sacrificing the goal completion time to reduce the risk of the decline in the quality of vegetables during the trip. Issues will become increasingly complex if the vehicle routing problem is flexible to changes that occur in the limit or the value of decision variables. The problems encountered in this case include heterogeneous multi fleet VRP, single source, single trip, and multi-product. Therefore, this research used genetic algorithm optimization method (GA) to solve the problem. Genetic algorithm is one of the heuristic methods, which is analogous to the process of evolution by natural selection phase, crossover and mutation. In this paper a simulation is performed by searching the optimum solution to the location of the distribution as the destination points. Optimum solutions are obtained in the form of division of highland vegetable distribution channels that meet the existing constraints. As a solution, there was reduction of the distribution time of about 1 hour 58 minutes or an increase in time efficiency by approximately 32.22% and a reduction of the fleet utilization by 1 fleet or an increase of fleet efficiency by 14.28%.
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Judul: Synthesis of Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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