Judul: Penyelesaian open vehicle routing problem menggunakan metode heuristik
Abstrak: This research is study of literature from the journal entitled A Heuristic Method for The Open Vehicle Routing Problem prepared by D Sariklis and S Powell in 2000. The issue is about management of goods distribution with a vehicle route that starts from the depot and stopped at the end customer, the vehicle is not required to return to the depot and each customer is visited by exactly one vehicle and its demand is totally satisfied. The objective is to generate the set of route that minimize the total travelling cost. This problem is an open problem to be solved using heuristic methods. The heuristic methods used in this study using Prim’s algorithm to find minimum spanning tree (MST) and the penalty method to modify the MST in order to form a chain. The heuristic methods are used to generate the set of routes that form a chain.
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Judul: The application of the heuristic method at the vehicle routing problem and its implementation at the PT Nippon Indosari Corpindo.
Abstrak: This paper is a case study in a division of PT Nippon Indosari Corpindo company. We used the vehicle routing problem with time windows (VRPTW) to formulate the distribution problem, which is a variation of the vehicle routing problem (VRP). In the VRP, all costumers have a time windows, so the service for the costumers must be completed in a specified time interval. The objective is to minimize the number of vehicles to serve all costumers in certain area and also to minimize the route length. As the VRPTW is a difficult problem in non polynomial hard problems, then we used the heuristic approach to solve the problem. In this paper, we used the nearest addition heuristic method to find the first solution. Next we used 2-Opt, Or-Opt, relocate, exchange, and cross methods to improve the first solution. In the last chapter of this paper, the results were compared to the current condition of the company. Key word: Vehicle routing problem, heuristic method, nearest addition heuristic method.
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Judul: Durability of Specific Immunoglobulin (Ig) Y Againts Influenza and Covid-19 in Sunscreen
Abstrak: The benefit of specific immunoglobulin Y (Ig Y) as an active ingredient in personal care products such as sunscreen has not been properly studied. Our study aims to evaluate the reliability of specific IgY against influenza and the COVID-19 virus in a sample sunscreen product. Specific IgY influenza and COVID-19 viruses were inserted in the sample sunscreen at two concentrations of 0.1% and 0.25%. Three treatments were observed: control (C) sunscreen without IgY, treatment 1 (T1) sunscreen with 0.1% IgY, and treatment 2 (T2) sunscreen with 0.25% IgY. Organoleptic observations were carried out to monitor changes in aroma, color, and texture, and sunscreen sampling was done every week for 6 weeks. The durability of IgY was evaluated using an enzyme-linked immunosorbent assay (ELISA) and a neutralization assay. Organoleptic observation from weeks 1 to 6 showed consistency in its aroma, color, and texture. Enzyme-linked immunosorbent assay and neutralization assay (NA) results of the T1 and T2 groups showed negative results except for sample T1 at week 5, which showed a positive result in the Influenza A ELISA. Based on the results, it seems that IgY concentrations of 0.1% or 0.25% were not optimal. However, this negative result might be due to low concentration of the IgY and the presence of beeswax, which inhibits IgY and causes it to dissolve in distilled water, thus preventing it from being detected in the assay.
Keyword: Immunoglobulin Y, Sunscreen, Influenza, COVID-19, Biological Activity