Archive for category Knowledge Area

Workshop on Data Analytics and Visualization

Data Modeling and Visualization is one of the branches in our optimization research. Our new research groups, Signifier Analytics, has been established to foster the development of knowledge and experience on how data can turn to insights. Two of our prominent researchers, Komarudin and Aziiz Sutrisno, shared their experience on a half-day workshop. Pak Komarudin talked about his experiences as a data scientist for a mining company in Indonesia, where he must predict the weather for the following weeks of operations based on previous year data. Pak Aziiz shared his experiences in analyzing social media for trends and how to best visualizes these data for giving insights.

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The workshop is conducted in two waves, one for our students and one for external publics. The external workshop is conducted at Kekini Co-Working Space, Cikini, Jakarta

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SEMS Play Day!

As part of our research in Serious Simulation Games or SSG, we are testing two of our serious games for public feedback. We called this event SEMS Play Day.

The first game that we are testing is the Project Management Game or PMG, and the second game is MAGPort SSG. PMG has a new redesign board to make it more portable, and MAGPort or Multi-Actor Game for Port Development is our new game that for the first time considering a multi-actor scenario.

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The participants provide very valuable feedbacks into the design and delivery of both games. They all appreciate the use of Serious Simulation Games for Learning.

We will be conducting more PlayDay Event in the future. So be sure to wait for our announcement.

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Reducing Cost of Road Maintenance for the Resources Industry

production-1891426_640Haul road in open mine has short durability. It is because haul road is constructed without asphalt/concrete pavement and passed by big vehicle with heavy load. There is some kind of decreasing quality of haul road such as improper cross section, inadequate roadside drainage, corrugations, potholes, ruts, and loose aggregate. Poor haul road quality will impact on increasing production costs and decreasing mine productivity. Usually open mine use motor grader to maintain the quality of haul road. Way of working of motor grader is to scrap the inadequate haul road surface.

There are some differences among the haul road segments such as characteristic, traffic density, kind of decreasing quality, durability, etc. Therefore, systematically grader route and schedule is needed to minimize the delay of haul road maintenance. Usually grader route and schedule just based on grader’s operator experience. There is no specific approach that can be used in grader route and schedule.

This research focused on grader route and schedule optimization in coal haul road maintenance. Optimization model in this research is designed using Bandit Algorithm. The objective of the optimization model is to minimize the maximum penalty. In this case, penalty is used to describe amount of loss that is caused by maintenance delay on each haul road segment. Grader start from the initial point to a road segment and moves over and over to the other road segment until working hour is over. Determination of he next road segment is based on weight of maintenance delay on each road segment. Greater the weight of the maintenance delay of a road segment, greater the probability of that road segment to be addressed by grader. Grader scraps if the road segment is late maintained and just passes if otherwise. When the working hour is over, grader stops moving and optimization model calculates the objective and records the route as a new solution. The steps are done again as many as have been determined (iteration). Solution with the best objective is chosen as the final solution.

With the probability, grader is not directly addressed to the road segment with the greatest maintenance delay weight to allow for the other road segments to be the next grader destination. This is because short term solutions have effect on long-term solution (whole solution); maybe the best short-term solution is not the best long-term solution. An example in a simpler problem is: we must determine route from city A to city D with 2 possible route that are A-B-D and A-C-D. With the distance between A-B < A-C, A-B is the best first movement. But for the overall movement, maybe A-B-D is not the closest route. Although the distance between A-B < A-C, distance of A-C and C-D can be closer than A-B and B-D.

Optimization model showed a significant cost savings for the mining operations by creating a more effective roads maintenance with reduce cost. With the pressure of low prices in the resources industry, a simple but yet complex optimization can help them stay more competitive.

This research is conducted by Denni and Dr. Komarudin.

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Can Biodiesel Industry achieve its target by 2025: an Agent Based Model Exploration

“Change is easy to purpose, hard to implement and especially hard to sustain”

-Andy Hargreaves

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As we know, biodiesel or Fatty Acid Methyl Ester (FAME) is one type of biofuel produced as a substitution of diesel fuel. In Indonesia, biodiesel is produced using crude palm oil by trans-esterification process. The usage of crude palm oil is performed because it sees that Indonesia is a nation with the biggest yield of crude palm oil in the Earth. In summation to the potential of its natural resources, the role of biodiesel as a substitute of diesel fuel is caused because it considers the benefits generated by biodiesel itself. Benefits include the so-called “carbon neutral”, the fuel produced biodiesel does not raise the output of carbon dioxide (CO2). The issue occurs because when the oil crop grows, it absorbs CO2 at the same amount as releasing fuel. In addition, biodiesel has biodegradable compounds that are firm and completely non-toxic, having in mind that biodiesel spills have less risk than diesel fuel. Biodiesel also has a higher flash point than diesel fuel, can be determined from its higher cetane value (> 57) than diesel fuel.

Still, the condition of biodiesel production in Indonesia faces complex problems. The concentration of biodiesel has never been fully attained, with the concentration of non-subsidized biodiesel that has not been carried out optimally. There are four major problems facing biodiesel production. Firstly, the concentration of biodiesel production is not maximal, especially in non-subsidized biodiesel production. Second, the condition of Indonesia’s domestic biodiesel production that began to decline from 2014 to 2015 due to lower oil costs. Tierce, the number of business entities that are abundant, but relatively small to fulfill the objective of production capability in 2025 amounted to 10.22 million KL. And the last and most important is the increasing CPO price, condition that causes the Biodiesel Market Index Price to be less frugal. This problem becomes the consideration of the biodiesel industry to continue to sell its biodiesel in Indonesia.

To avoid such problems, agent-based modeling can be used to predict the impact of policies on influential actors to gain a deep understanding of the behavior and decisions made by the biodiesel industry by looking at the types of biodiesel industry in Indonesia that are differentiated by the type of production capacity that can be handled by the biodiesel industry, decision-making that depends on the type of industry, how the biodiesel industry calculates the expenditure and income as well as the learning gained by the biodiesel industry after large-scale production. This agent-based modeling is done with two policy alternatives, namely price determination of biodiesel market index and subsidy of installed capacity of the biodiesel plant.

The results obtained from this agent-based modeling show that the policy of adding the biodiesel plant installed capacity has a good impact in increasing the fulfillment of biodiesel production, the adoption and competition that occurs in the tender, and the profits gained by the biodiesel industry. Even so, the government should count the costs to be incurred and the net income from biodiesel industry, so the biodiesel production targets can be successfully accomplished.

This research is conducted by Vicky Larasvasti Respati and Akhmad Hidayatno

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This is What You Should Do When You Have No Doraemon’s Magical-Anywhere-Door

There are times when we wish Doraemon’s magical-anywhere-door really does exist. If so, we can reach our destination without having to travel miles in a long time. But, since Doraemon does not exist, fortunately there is something we can do to at least save the mileage and time we sacrificed to travel from one to another places. Especially in case of post men or delivery couriers who have to visit a lot of destinations in such limited amount of time and capability.

Recently, a research assistant from Systems Engineering, Modeling, and Simulation Laboratory from Industrial Engineering major, Universitas Indonesia is conducting a research about Vehicle Routing Problem with Time Windows to optimize distribution route and schedule. It was first inspired by Indonesia’s current logistic condition which is still not optimal. It is proven by the decreasing index of Indonesia’s logistic performance during the past five years. One of the reason is the high Indonesia’s logistic cost which can be considered as the highest logistic cost in the world. And the one that contributes almost half of the logistic cost is transportation cost.

On the other side, customer needs are rising annually. Moreover, the growing online shopping market create an increasing demand of same-day delivery service. Based on McKinsey survey, online retailers as the main originator of B2C shipments, have a large interest to reduce delivery time in order to foster the products sale. Therefore, we need a better planning of distribution route and schedule, especially for delivery service providers and courier companies.

The purpose of research conducted at SEMS Laboratory about Vehicle Routing Problem with Time Windows (VRPTW) is to find the most optimum distribution route with lowest total distance yet still manage to fulfill all demand and considering the constraints of vehicle capacity and customers’ time windows.

Since VRPTW belongs to NP-hard optimization problems, our researcher used heuristic method which is translated to Netbeans 8.1 software in C++ programming language. They also use local search to perform simple iterations to produce fairly accurate solutions. Local search methods which are used in this study are exchange, two-opt, and insert. They can be applied to customers in the same route (intra-route) and customers in different routes (inter-route). Basically, these methods perform some iterations of moves that determine the most optimum combination and sequence of customers to visit. This will be finalized by using Lin Kernighan Helsgaun algorithm. The iteration will stop once it can not generate a better solution.

Fig 1. Illustration of 2-opt intra-route move

Fig 1. Illustration of 2-opt intra-route move

The resulting improvements will ultimately result in reduced transportation costs. Thus, vehicle routing problem with time windows can be a solution for urban logistic problems. So, when you do not have any Doraemon’s magical door, make yourself sure that at least you have a well-planned distribution route and schedule!

This Research is Conducted by Vincencia Sydneyta and Dr. Komarudin

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